From: Josh Poimboeuf jpoimboe@redhat.com

commit dcc914f44f065ef73685b37e59877a5bb3cb7358 upstream.

In preparation for the new 'objtool undwarf generate' command, which will rely on 'objtool check', move the checking code from builtin-check.c to check.c where it can be used by other commands.

Signed-off-by: Josh Poimboeuf jpoimboe@redhat.com Reviewed-by: Jiri Slaby jslaby@suse.cz Cc: Andy Lutomirski luto@kernel.org Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/294c5c695fd73c1a5000bbe5960a7c9bec4ee6b4.1498659915... Signed-off-by: Ingo Molnar mingo@kernel.org [backported by hand to 4.9, this was a pain... - gregkh] Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/objtool/Build | 1 + tools/objtool/builtin-check.c | 1346 +-------------------------------- tools/objtool/check.c | 1327 ++++++++++++++++++++++++++++++++ tools/objtool/check.h | 51 ++ 4 files changed, 1392 insertions(+), 1333 deletions(-) create mode 100644 tools/objtool/check.c create mode 100644 tools/objtool/check.h

diff --git a/tools/objtool/Build b/tools/objtool/Build index d6cdece5e58b..6f2e1987c4d9 100644 --- a/tools/objtool/Build +++ b/tools/objtool/Build @@ -1,5 +1,6 @@ objtool-y += arch/$(SRCARCH)/ objtool-y += builtin-check.o +objtool-y += check.o objtool-y += elf.o objtool-y += special.o objtool-y += objtool.o diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 2aa7313e31f2..365c34ecab26 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2015 Josh Poimboeuf jpoimboe@redhat.com + * Copyright (C) 2015-2017 Josh Poimboeuf jpoimboe@redhat.com * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -25,1352 +25,32 @@ * For more information, see tools/objtool/Documentation/stack-validation.txt. */

-#include <string.h> -#include <stdlib.h> #include <subcmd/parse-options.h> - #include "builtin.h" -#include "elf.h" -#include "special.h" -#include "arch.h" -#include "warn.h" - -#include <linux/hashtable.h> - -#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) - -#define STATE_FP_SAVED 0x1 -#define STATE_FP_SETUP 0x2 -#define STATE_FENTRY 0x4 - -struct instruction { - struct list_head list; - struct hlist_node hash; - struct section *sec; - unsigned long offset; - unsigned int len, state; - unsigned char type; - unsigned long immediate; - bool alt_group, visited, dead_end, ignore_alts; - struct symbol *call_dest; - struct instruction *jump_dest; - struct list_head alts; - struct symbol *func; -}; - -struct alternative { - struct list_head list; - struct instruction *insn; -}; - -struct objtool_file { - struct elf *elf; - struct list_head insn_list; - DECLARE_HASHTABLE(insn_hash, 16); - struct section *rodata, *whitelist; - bool ignore_unreachables, c_file; -}; - -const char *objname; -static bool nofp; - -static struct instruction *find_insn(struct objtool_file *file, - struct section *sec, unsigned long offset) -{ - struct instruction *insn; - - hash_for_each_possible(file->insn_hash, insn, hash, offset) - if (insn->sec == sec && insn->offset == offset) - return insn; - - return NULL; -} - -static struct instruction *next_insn_same_sec(struct objtool_file *file, - struct instruction *insn) -{ - struct instruction *next = list_next_entry(insn, list); - - if (&next->list == &file->insn_list || next->sec != insn->sec) - return NULL; - - return next; -} - -static bool gcov_enabled(struct objtool_file *file) -{ - struct section *sec; - struct symbol *sym; - - list_for_each_entry(sec, &file->elf->sections, list) - list_for_each_entry(sym, &sec->symbol_list, list) - if (!strncmp(sym->name, "__gcov_.", 8)) - return true; - - return false; -} - -#define for_each_insn(file, insn) \ - list_for_each_entry(insn, &file->insn_list, list) - -#define func_for_each_insn(file, func, insn) \ - for (insn = find_insn(file, func->sec, func->offset); \ - insn && &insn->list != &file->insn_list && \ - insn->sec == func->sec && \ - insn->offset < func->offset + func->len; \ - insn = list_next_entry(insn, list)) - -#define func_for_each_insn_continue_reverse(file, func, insn) \ - for (insn = list_prev_entry(insn, list); \ - &insn->list != &file->insn_list && \ - insn->sec == func->sec && insn->offset >= func->offset; \ - insn = list_prev_entry(insn, list)) - -#define sec_for_each_insn_from(file, insn) \ - for (; insn; insn = next_insn_same_sec(file, insn)) - - -/* - * Check if the function has been manually whitelisted with the - * STACK_FRAME_NON_STANDARD macro, or if it should be automatically whitelisted - * due to its use of a context switching instruction. - */ -static bool ignore_func(struct objtool_file *file, struct symbol *func) -{ - struct rela *rela; - struct instruction *insn; - - /* check for STACK_FRAME_NON_STANDARD */ - if (file->whitelist && file->whitelist->rela) - list_for_each_entry(rela, &file->whitelist->rela->rela_list, list) { - if (rela->sym->type == STT_SECTION && - rela->sym->sec == func->sec && - rela->addend == func->offset) - return true; - if (rela->sym->type == STT_FUNC && rela->sym == func) - return true; - } - - /* check if it has a context switching instruction */ - func_for_each_insn(file, func, insn) - if (insn->type == INSN_CONTEXT_SWITCH) - return true; - - return false; -} - -/* - * This checks to see if the given function is a "noreturn" function. - * - * For global functions which are outside the scope of this object file, we - * have to keep a manual list of them. - * - * For local functions, we have to detect them manually by simply looking for - * the lack of a return instruction. - * - * Returns: - * -1: error - * 0: no dead end - * 1: dead end - */ -static int __dead_end_function(struct objtool_file *file, struct symbol *func, - int recursion) -{ - int i; - struct instruction *insn; - bool empty = true; - - /* - * Unfortunately these have to be hard coded because the noreturn - * attribute isn't provided in ELF data. - */ - static const char * const global_noreturns[] = { - "__stack_chk_fail", - "panic", - "do_exit", - "do_task_dead", - "__module_put_and_exit", - "complete_and_exit", - "kvm_spurious_fault", - "__reiserfs_panic", - "lbug_with_loc" - }; - - if (func->bind == STB_WEAK) - return 0; - - if (func->bind == STB_GLOBAL) - for (i = 0; i < ARRAY_SIZE(global_noreturns); i++) - if (!strcmp(func->name, global_noreturns[i])) - return 1; - - if (!func->sec) - return 0; - - func_for_each_insn(file, func, insn) { - empty = false; - - if (insn->type == INSN_RETURN) - return 0; - } - - if (empty) - return 0; - - /* - * A function can have a sibling call instead of a return. In that - * case, the function's dead-end status depends on whether the target - * of the sibling call returns. - */ - func_for_each_insn(file, func, insn) { - if (insn->sec != func->sec || - insn->offset >= func->offset + func->len) - break; - - if (insn->type == INSN_JUMP_UNCONDITIONAL) { - struct instruction *dest = insn->jump_dest; - struct symbol *dest_func; - - if (!dest) - /* sibling call to another file */ - return 0; - - if (dest->sec != func->sec || - dest->offset < func->offset || - dest->offset >= func->offset + func->len) { - /* local sibling call */ - dest_func = find_symbol_by_offset(dest->sec, - dest->offset); - if (!dest_func) - continue; - - if (recursion == 5) { - WARN_FUNC("infinite recursion (objtool bug!)", - dest->sec, dest->offset); - return -1; - } - - return __dead_end_function(file, dest_func, - recursion + 1); - } - } - - if (insn->type == INSN_JUMP_DYNAMIC && list_empty(&insn->alts)) - /* sibling call */ - return 0; - } - - return 1; -} - -static int dead_end_function(struct objtool_file *file, struct symbol *func) -{ - return __dead_end_function(file, func, 0); -} - -/* - * Call the arch-specific instruction decoder for all the instructions and add - * them to the global instruction list. - */ -static int decode_instructions(struct objtool_file *file) -{ - struct section *sec; - struct symbol *func; - unsigned long offset; - struct instruction *insn; - int ret; - - list_for_each_entry(sec, &file->elf->sections, list) { - - if (!(sec->sh.sh_flags & SHF_EXECINSTR)) - continue; - - for (offset = 0; offset < sec->len; offset += insn->len) { - insn = malloc(sizeof(*insn)); - memset(insn, 0, sizeof(*insn)); - - INIT_LIST_HEAD(&insn->alts); - insn->sec = sec; - insn->offset = offset; - - ret = arch_decode_instruction(file->elf, sec, offset, - sec->len - offset, - &insn->len, &insn->type, - &insn->immediate); - if (ret) - return ret; - - if (!insn->type || insn->type > INSN_LAST) { - WARN_FUNC("invalid instruction type %d", - insn->sec, insn->offset, insn->type); - return -1; - } - - hash_add(file->insn_hash, &insn->hash, insn->offset); - list_add_tail(&insn->list, &file->insn_list); - } - - list_for_each_entry(func, &sec->symbol_list, list) { - if (func->type != STT_FUNC) - continue; - - if (!find_insn(file, sec, func->offset)) { - WARN("%s(): can't find starting instruction", - func->name); - return -1; - } - - func_for_each_insn(file, func, insn) - if (!insn->func) - insn->func = func; - } - } - - return 0; -} - -/* - * Find all uses of the unreachable() macro, which are code path dead ends. - */ -static int add_dead_ends(struct objtool_file *file) -{ - struct section *sec; - struct rela *rela; - struct instruction *insn; - bool found; - - sec = find_section_by_name(file->elf, ".rela__unreachable"); - if (!sec) - return 0; - - list_for_each_entry(rela, &sec->rela_list, list) { - if (rela->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in .rela__unreachable"); - return -1; - } - insn = find_insn(file, rela->sym->sec, rela->addend); - if (insn) - insn = list_prev_entry(insn, list); - else if (rela->addend == rela->sym->sec->len) { - found = false; - list_for_each_entry_reverse(insn, &file->insn_list, list) { - if (insn->sec == rela->sym->sec) { - found = true; - break; - } - } - - if (!found) { - WARN("can't find unreachable insn at %s+0x%x", - rela->sym->sec->name, rela->addend); - return -1; - } - } else { - WARN("can't find unreachable insn at %s+0x%x", - rela->sym->sec->name, rela->addend); - return -1; - } - - insn->dead_end = true; - } - - return 0; -} - -/* - * Warnings shouldn't be reported for ignored functions. - */ -static void add_ignores(struct objtool_file *file) -{ - struct instruction *insn; - struct section *sec; - struct symbol *func; - - list_for_each_entry(sec, &file->elf->sections, list) { - list_for_each_entry(func, &sec->symbol_list, list) { - if (func->type != STT_FUNC) - continue; - - if (!ignore_func(file, func)) - continue; - - func_for_each_insn(file, func, insn) - insn->visited = true; - } - } -} - -/* - * FIXME: For now, just ignore any alternatives which add retpolines. This is - * a temporary hack, as it doesn't allow ORC to unwind from inside a retpoline. - * But it at least allows objtool to understand the control flow *around* the - * retpoline. - */ -static int add_nospec_ignores(struct objtool_file *file) -{ - struct section *sec; - struct rela *rela; - struct instruction *insn; - - sec = find_section_by_name(file->elf, ".rela.discard.nospec"); - if (!sec) - return 0; - - list_for_each_entry(rela, &sec->rela_list, list) { - if (rela->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in %s", sec->name); - return -1; - } - - insn = find_insn(file, rela->sym->sec, rela->addend); - if (!insn) { - WARN("bad .discard.nospec entry"); - return -1; - } - - insn->ignore_alts = true; - } - - return 0; -} - -/* - * Find the destination instructions for all jumps. - */ -static int add_jump_destinations(struct objtool_file *file) -{ - struct instruction *insn; - struct rela *rela; - struct section *dest_sec; - unsigned long dest_off; - - for_each_insn(file, insn) { - if (insn->type != INSN_JUMP_CONDITIONAL && - insn->type != INSN_JUMP_UNCONDITIONAL) - continue; - - /* skip ignores */ - if (insn->visited) - continue; - - rela = find_rela_by_dest_range(insn->sec, insn->offset, - insn->len); - if (!rela) { - dest_sec = insn->sec; - dest_off = insn->offset + insn->len + insn->immediate; - } else if (rela->sym->type == STT_SECTION) { - dest_sec = rela->sym->sec; - dest_off = rela->addend + 4; - } else if (rela->sym->sec->idx) { - dest_sec = rela->sym->sec; - dest_off = rela->sym->sym.st_value + rela->addend + 4; - } else if (strstr(rela->sym->name, "_indirect_thunk_")) { - /* - * Retpoline jumps are really dynamic jumps in - * disguise, so convert them accordingly. - */ - insn->type = INSN_JUMP_DYNAMIC; - continue; - } else { - /* sibling call */ - insn->jump_dest = 0; - continue; - } - - insn->jump_dest = find_insn(file, dest_sec, dest_off); - if (!insn->jump_dest) { - - /* - * This is a special case where an alt instruction - * jumps past the end of the section. These are - * handled later in handle_group_alt(). - */ - if (!strcmp(insn->sec->name, ".altinstr_replacement")) - continue; - - WARN_FUNC("can't find jump dest instruction at %s+0x%lx", - insn->sec, insn->offset, dest_sec->name, - dest_off); - return -1; - } - } - - return 0; -} - -/* - * Find the destination instructions for all calls. - */ -static int add_call_destinations(struct objtool_file *file) -{ - struct instruction *insn; - unsigned long dest_off; - struct rela *rela; - - for_each_insn(file, insn) { - if (insn->type != INSN_CALL) - continue; - - rela = find_rela_by_dest_range(insn->sec, insn->offset, - insn->len); - if (!rela) { - dest_off = insn->offset + insn->len + insn->immediate; - insn->call_dest = find_symbol_by_offset(insn->sec, - dest_off); - /* - * FIXME: Thanks to retpolines, it's now considered - * normal for a function to call within itself. So - * disable this warning for now. - */ -#if 0 - if (!insn->call_dest) { - WARN_FUNC("can't find call dest symbol at offset 0x%lx", - insn->sec, insn->offset, dest_off); - return -1; - } -#endif - } else if (rela->sym->type == STT_SECTION) { - insn->call_dest = find_symbol_by_offset(rela->sym->sec, - rela->addend+4); - if (!insn->call_dest || - insn->call_dest->type != STT_FUNC) { - WARN_FUNC("can't find call dest symbol at %s+0x%x", - insn->sec, insn->offset, - rela->sym->sec->name, - rela->addend + 4); - return -1; - } - } else - insn->call_dest = rela->sym; - } - - return 0; -} - -/* - * The .alternatives section requires some extra special care, over and above - * what other special sections require: - * - * 1. Because alternatives are patched in-place, we need to insert a fake jump - * instruction at the end so that validate_branch() skips all the original - * replaced instructions when validating the new instruction path. - * - * 2. An added wrinkle is that the new instruction length might be zero. In - * that case the old instructions are replaced with noops. We simulate that - * by creating a fake jump as the only new instruction. - * - * 3. In some cases, the alternative section includes an instruction which - * conditionally jumps to the _end_ of the entry. We have to modify these - * jumps' destinations to point back to .text rather than the end of the - * entry in .altinstr_replacement. - * - * 4. It has been requested that we don't validate the !POPCNT feature path - * which is a "very very small percentage of machines". - */ -static int handle_group_alt(struct objtool_file *file, - struct special_alt *special_alt, - struct instruction *orig_insn, - struct instruction **new_insn) -{ - struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump; - unsigned long dest_off; - - last_orig_insn = NULL; - insn = orig_insn; - sec_for_each_insn_from(file, insn) { - if (insn->offset >= special_alt->orig_off + special_alt->orig_len) - break; - - if (special_alt->skip_orig) - insn->type = INSN_NOP; - - insn->alt_group = true; - last_orig_insn = insn; - } - - if (!next_insn_same_sec(file, last_orig_insn)) { - WARN("%s: don't know how to handle alternatives at end of section", - special_alt->orig_sec->name); - return -1; - } - - fake_jump = malloc(sizeof(*fake_jump)); - if (!fake_jump) { - WARN("malloc failed"); - return -1; - } - memset(fake_jump, 0, sizeof(*fake_jump)); - INIT_LIST_HEAD(&fake_jump->alts); - fake_jump->sec = special_alt->new_sec; - fake_jump->offset = -1; - fake_jump->type = INSN_JUMP_UNCONDITIONAL; - fake_jump->jump_dest = list_next_entry(last_orig_insn, list); - - if (!special_alt->new_len) { - *new_insn = fake_jump; - return 0; - } - - last_new_insn = NULL; - insn = *new_insn; - sec_for_each_insn_from(file, insn) { - if (insn->offset >= special_alt->new_off + special_alt->new_len) - break; - - last_new_insn = insn; - - if (insn->type != INSN_JUMP_CONDITIONAL && - insn->type != INSN_JUMP_UNCONDITIONAL) - continue; - - if (!insn->immediate) - continue; - - dest_off = insn->offset + insn->len + insn->immediate; - if (dest_off == special_alt->new_off + special_alt->new_len) - insn->jump_dest = fake_jump; - - if (!insn->jump_dest) { - WARN_FUNC("can't find alternative jump destination", - insn->sec, insn->offset); - return -1; - } - } - - if (!last_new_insn) { - WARN_FUNC("can't find last new alternative instruction", - special_alt->new_sec, special_alt->new_off); - return -1; - } - - list_add(&fake_jump->list, &last_new_insn->list); - - return 0; -} - -/* - * A jump table entry can either convert a nop to a jump or a jump to a nop. - * If the original instruction is a jump, make the alt entry an effective nop - * by just skipping the original instruction. - */ -static int handle_jump_alt(struct objtool_file *file, - struct special_alt *special_alt, - struct instruction *orig_insn, - struct instruction **new_insn) -{ - if (orig_insn->type == INSN_NOP) - return 0; - - if (orig_insn->type != INSN_JUMP_UNCONDITIONAL) { - WARN_FUNC("unsupported instruction at jump label", - orig_insn->sec, orig_insn->offset); - return -1; - } - - *new_insn = list_next_entry(orig_insn, list); - return 0; -} - -/* - * Read all the special sections which have alternate instructions which can be - * patched in or redirected to at runtime. Each instruction having alternate - * instruction(s) has them added to its insn->alts list, which will be - * traversed in validate_branch(). - */ -static int add_special_section_alts(struct objtool_file *file) -{ - struct list_head special_alts; - struct instruction *orig_insn, *new_insn; - struct special_alt *special_alt, *tmp; - struct alternative *alt; - int ret; +#include "check.h"

- ret = special_get_alts(file->elf, &special_alts); - if (ret) - return ret; +bool nofp;

- list_for_each_entry_safe(special_alt, tmp, &special_alts, list) { - - orig_insn = find_insn(file, special_alt->orig_sec, - special_alt->orig_off); - if (!orig_insn) { - WARN_FUNC("special: can't find orig instruction", - special_alt->orig_sec, special_alt->orig_off); - ret = -1; - goto out; - } - - /* Ignore retpoline alternatives. */ - if (orig_insn->ignore_alts) - continue; - - new_insn = NULL; - if (!special_alt->group || special_alt->new_len) { - new_insn = find_insn(file, special_alt->new_sec, - special_alt->new_off); - if (!new_insn) { - WARN_FUNC("special: can't find new instruction", - special_alt->new_sec, - special_alt->new_off); - ret = -1; - goto out; - } - } - - if (special_alt->group) { - ret = handle_group_alt(file, special_alt, orig_insn, - &new_insn); - if (ret) - goto out; - } else if (special_alt->jump_or_nop) { - ret = handle_jump_alt(file, special_alt, orig_insn, - &new_insn); - if (ret) - goto out; - } - - alt = malloc(sizeof(*alt)); - if (!alt) { - WARN("malloc failed"); - ret = -1; - goto out; - } - - alt->insn = new_insn; - list_add_tail(&alt->list, &orig_insn->alts); - - list_del(&special_alt->list); - free(special_alt); - } - -out: - return ret; -} - -static int add_switch_table(struct objtool_file *file, struct symbol *func, - struct instruction *insn, struct rela *table, - struct rela *next_table) -{ - struct rela *rela = table; - struct instruction *alt_insn; - struct alternative *alt; - - list_for_each_entry_from(rela, &file->rodata->rela->rela_list, list) { - if (rela == next_table) - break; - - if (rela->sym->sec != insn->sec || - rela->addend <= func->offset || - rela->addend >= func->offset + func->len) - break; - - alt_insn = find_insn(file, insn->sec, rela->addend); - if (!alt_insn) { - WARN("%s: can't find instruction at %s+0x%x", - file->rodata->rela->name, insn->sec->name, - rela->addend); - return -1; - } - - alt = malloc(sizeof(*alt)); - if (!alt) { - WARN("malloc failed"); - return -1; - } - - alt->insn = alt_insn; - list_add_tail(&alt->list, &insn->alts); - } - - return 0; -} - -/* - * find_switch_table() - Given a dynamic jump, find the switch jump table in - * .rodata associated with it. - * - * There are 3 basic patterns: - * - * 1. jmpq *[rodata addr](,%reg,8) - * - * This is the most common case by far. It jumps to an address in a simple - * jump table which is stored in .rodata. - * - * 2. jmpq *[rodata addr](%rip) - * - * This is caused by a rare GCC quirk, currently only seen in three driver - * functions in the kernel, only with certain obscure non-distro configs. - * - * As part of an optimization, GCC makes a copy of an existing switch jump - * table, modifies it, and then hard-codes the jump (albeit with an indirect - * jump) to use a single entry in the table. The rest of the jump table and - * some of its jump targets remain as dead code. - * - * In such a case we can just crudely ignore all unreachable instruction - * warnings for the entire object file. Ideally we would just ignore them - * for the function, but that would require redesigning the code quite a - * bit. And honestly that's just not worth doing: unreachable instruction - * warnings are of questionable value anyway, and this is such a rare issue. - * - * 3. mov [rodata addr],%reg1 - * ... some instructions ... - * jmpq *(%reg1,%reg2,8) - * - * This is a fairly uncommon pattern which is new for GCC 6. As of this - * writing, there are 11 occurrences of it in the allmodconfig kernel. - * - * TODO: Once we have DWARF CFI and smarter instruction decoding logic, - * ensure the same register is used in the mov and jump instructions. - */ -static struct rela *find_switch_table(struct objtool_file *file, - struct symbol *func, - struct instruction *insn) -{ - struct rela *text_rela, *rodata_rela; - struct instruction *orig_insn = insn; - - text_rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len); - if (text_rela && text_rela->sym == file->rodata->sym) { - /* case 1 */ - rodata_rela = find_rela_by_dest(file->rodata, - text_rela->addend); - if (rodata_rela) - return rodata_rela; - - /* case 2 */ - rodata_rela = find_rela_by_dest(file->rodata, - text_rela->addend + 4); - if (!rodata_rela) - return NULL; - file->ignore_unreachables = true; - return rodata_rela; - } - - /* case 3 */ - func_for_each_insn_continue_reverse(file, func, insn) { - if (insn->type == INSN_JUMP_DYNAMIC) - break; - - /* allow small jumps within the range */ - if (insn->type == INSN_JUMP_UNCONDITIONAL && - insn->jump_dest && - (insn->jump_dest->offset <= insn->offset || - insn->jump_dest->offset > orig_insn->offset)) - break; - - /* look for a relocation which references .rodata */ - text_rela = find_rela_by_dest_range(insn->sec, insn->offset, - insn->len); - if (!text_rela || text_rela->sym != file->rodata->sym) - continue; - - /* - * Make sure the .rodata address isn't associated with a - * symbol. gcc jump tables are anonymous data. - */ - if (find_symbol_containing(file->rodata, text_rela->addend)) - continue; - - return find_rela_by_dest(file->rodata, text_rela->addend); - } - - return NULL; -} - -static int add_func_switch_tables(struct objtool_file *file, - struct symbol *func) -{ - struct instruction *insn, *prev_jump = NULL; - struct rela *rela, *prev_rela = NULL; - int ret; - - func_for_each_insn(file, func, insn) { - if (insn->type != INSN_JUMP_DYNAMIC) - continue; - - rela = find_switch_table(file, func, insn); - if (!rela) - continue; - - /* - * We found a switch table, but we don't know yet how big it - * is. Don't add it until we reach the end of the function or - * the beginning of another switch table in the same function. - */ - if (prev_jump) { - ret = add_switch_table(file, func, prev_jump, prev_rela, - rela); - if (ret) - return ret; - } - - prev_jump = insn; - prev_rela = rela; - } - - if (prev_jump) { - ret = add_switch_table(file, func, prev_jump, prev_rela, NULL); - if (ret) - return ret; - } - - return 0; -} - -/* - * For some switch statements, gcc generates a jump table in the .rodata - * section which contains a list of addresses within the function to jump to. - * This finds these jump tables and adds them to the insn->alts lists. - */ -static int add_switch_table_alts(struct objtool_file *file) -{ - struct section *sec; - struct symbol *func; - int ret; - - if (!file->rodata || !file->rodata->rela) - return 0; - - list_for_each_entry(sec, &file->elf->sections, list) { - list_for_each_entry(func, &sec->symbol_list, list) { - if (func->type != STT_FUNC) - continue; - - ret = add_func_switch_tables(file, func); - if (ret) - return ret; - } - } - - return 0; -} - -static int decode_sections(struct objtool_file *file) -{ - int ret; - - ret = decode_instructions(file); - if (ret) - return ret; - - ret = add_dead_ends(file); - if (ret) - return ret; - - add_ignores(file); - - ret = add_nospec_ignores(file); - if (ret) - return ret; - - ret = add_jump_destinations(file); - if (ret) - return ret; - - ret = add_call_destinations(file); - if (ret) - return ret; - - ret = add_special_section_alts(file); - if (ret) - return ret; - - ret = add_switch_table_alts(file); - if (ret) - return ret; - - return 0; -} - -static bool is_fentry_call(struct instruction *insn) -{ - if (insn->type == INSN_CALL && - insn->call_dest->type == STT_NOTYPE && - !strcmp(insn->call_dest->name, "__fentry__")) - return true; - - return false; -} - -static bool has_modified_stack_frame(struct instruction *insn) -{ - return (insn->state & STATE_FP_SAVED) || - (insn->state & STATE_FP_SETUP); -} - -static bool has_valid_stack_frame(struct instruction *insn) -{ - return (insn->state & STATE_FP_SAVED) && - (insn->state & STATE_FP_SETUP); -} - -static unsigned int frame_state(unsigned long state) -{ - return (state & (STATE_FP_SAVED | STATE_FP_SETUP)); -} - -/* - * Follow the branch starting at the given instruction, and recursively follow - * any other branches (jumps). Meanwhile, track the frame pointer state at - * each instruction and validate all the rules described in - * tools/objtool/Documentation/stack-validation.txt. - */ -static int validate_branch(struct objtool_file *file, - struct instruction *first, unsigned char first_state) -{ - struct alternative *alt; - struct instruction *insn; - struct section *sec; - struct symbol *func = NULL; - unsigned char state; - int ret; - - insn = first; - sec = insn->sec; - state = first_state; - - if (insn->alt_group && list_empty(&insn->alts)) { - WARN_FUNC("don't know how to handle branch to middle of alternative instruction group", - sec, insn->offset); - return 1; - } - - while (1) { - if (file->c_file && insn->func) { - if (func && func != insn->func) { - WARN("%s() falls through to next function %s()", - func->name, insn->func->name); - return 1; - } - - func = insn->func; - } - - if (insn->visited) { - if (frame_state(insn->state) != frame_state(state)) { - WARN_FUNC("frame pointer state mismatch", - sec, insn->offset); - return 1; - } - - return 0; - } - - insn->visited = true; - insn->state = state; - - list_for_each_entry(alt, &insn->alts, list) { - ret = validate_branch(file, alt->insn, state); - if (ret) - return 1; - } - - switch (insn->type) { - - case INSN_FP_SAVE: - if (!nofp) { - if (state & STATE_FP_SAVED) { - WARN_FUNC("duplicate frame pointer save", - sec, insn->offset); - return 1; - } - state |= STATE_FP_SAVED; - } - break; - - case INSN_FP_SETUP: - if (!nofp) { - if (state & STATE_FP_SETUP) { - WARN_FUNC("duplicate frame pointer setup", - sec, insn->offset); - return 1; - } - state |= STATE_FP_SETUP; - } - break; - - case INSN_FP_RESTORE: - if (!nofp) { - if (has_valid_stack_frame(insn)) - state &= ~STATE_FP_SETUP; - - state &= ~STATE_FP_SAVED; - } - break; - - case INSN_RETURN: - if (!nofp && has_modified_stack_frame(insn)) { - WARN_FUNC("return without frame pointer restore", - sec, insn->offset); - return 1; - } - return 0; - - case INSN_CALL: - if (is_fentry_call(insn)) { - state |= STATE_FENTRY; - break; - } - - ret = dead_end_function(file, insn->call_dest); - if (ret == 1) - return 0; - if (ret == -1) - return 1; - - /* fallthrough */ - case INSN_CALL_DYNAMIC: - if (!nofp && !has_valid_stack_frame(insn)) { - WARN_FUNC("call without frame pointer save/setup", - sec, insn->offset); - return 1; - } - break; - - case INSN_JUMP_CONDITIONAL: - case INSN_JUMP_UNCONDITIONAL: - if (insn->jump_dest) { - ret = validate_branch(file, insn->jump_dest, - state); - if (ret) - return 1; - } else if (has_modified_stack_frame(insn)) { - WARN_FUNC("sibling call from callable instruction with changed frame pointer", - sec, insn->offset); - return 1; - } /* else it's a sibling call */ - - if (insn->type == INSN_JUMP_UNCONDITIONAL) - return 0; - - break; - - case INSN_JUMP_DYNAMIC: - if (list_empty(&insn->alts) && - has_modified_stack_frame(insn)) { - WARN_FUNC("sibling call from callable instruction with changed frame pointer", - sec, insn->offset); - return 1; - } - - return 0; - - default: - break; - } - - if (insn->dead_end) - return 0; - - insn = next_insn_same_sec(file, insn); - if (!insn) { - WARN("%s: unexpected end of section", sec->name); - return 1; - } - } - - return 0; -} - -static bool is_kasan_insn(struct instruction *insn) -{ - return (insn->type == INSN_CALL && - !strcmp(insn->call_dest->name, "__asan_handle_no_return")); -} - -static bool is_ubsan_insn(struct instruction *insn) -{ - return (insn->type == INSN_CALL && - !strcmp(insn->call_dest->name, - "__ubsan_handle_builtin_unreachable")); -} - -static bool ignore_unreachable_insn(struct symbol *func, - struct instruction *insn) -{ - int i; - - if (insn->type == INSN_NOP) - return true; - - /* - * Check if this (or a subsequent) instruction is related to - * CONFIG_UBSAN or CONFIG_KASAN. - * - * End the search at 5 instructions to avoid going into the weeds. - */ - for (i = 0; i < 5; i++) { - - if (is_kasan_insn(insn) || is_ubsan_insn(insn)) - return true; - - if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest) { - insn = insn->jump_dest; - continue; - } - - if (insn->offset + insn->len >= func->offset + func->len) - break; - insn = list_next_entry(insn, list); - } - - return false; -} - -static int validate_functions(struct objtool_file *file) -{ - struct section *sec; - struct symbol *func; - struct instruction *insn; - int ret, warnings = 0; - - list_for_each_entry(sec, &file->elf->sections, list) { - list_for_each_entry(func, &sec->symbol_list, list) { - if (func->type != STT_FUNC) - continue; - - insn = find_insn(file, sec, func->offset); - if (!insn) - continue; - - ret = validate_branch(file, insn, 0); - warnings += ret; - } - } - - list_for_each_entry(sec, &file->elf->sections, list) { - list_for_each_entry(func, &sec->symbol_list, list) { - if (func->type != STT_FUNC) - continue; - - func_for_each_insn(file, func, insn) { - if (insn->visited) - continue; - - insn->visited = true; - - if (file->ignore_unreachables || warnings || - ignore_unreachable_insn(func, insn)) - continue; - - /* - * gcov produces a lot of unreachable - * instructions. If we get an unreachable - * warning and the file has gcov enabled, just - * ignore it, and all other such warnings for - * the file. - */ - if (!file->ignore_unreachables && - gcov_enabled(file)) { - file->ignore_unreachables = true; - continue; - } - - WARN_FUNC("function has unreachable instruction", insn->sec, insn->offset); - warnings++; - } - } - } - - return warnings; -} - -static int validate_uncallable_instructions(struct objtool_file *file) -{ - struct instruction *insn; - int warnings = 0; - - for_each_insn(file, insn) { - if (!insn->visited && insn->type == INSN_RETURN) { - - /* - * Don't warn about call instructions in unvisited - * retpoline alternatives. - */ - if (!strcmp(insn->sec->name, ".altinstr_replacement")) - continue; - - WARN_FUNC("return instruction outside of a callable function", - insn->sec, insn->offset); - warnings++; - } - } - - return warnings; -} - -static void cleanup(struct objtool_file *file) -{ - struct instruction *insn, *tmpinsn; - struct alternative *alt, *tmpalt; - - list_for_each_entry_safe(insn, tmpinsn, &file->insn_list, list) { - list_for_each_entry_safe(alt, tmpalt, &insn->alts, list) { - list_del(&alt->list); - free(alt); - } - list_del(&insn->list); - hash_del(&insn->hash); - free(insn); - } - elf_close(file->elf); -} - -const char * const check_usage[] = { +static const char * const check_usage[] = { "objtool check [<options>] file.o", NULL, };

+const struct option check_options[] = { + OPT_BOOLEAN('f', "no-fp", &nofp, "Skip frame pointer validation"), + OPT_END(), +}; + int cmd_check(int argc, const char **argv) { - struct objtool_file file; - int ret, warnings = 0; + const char *objname;

- const struct option options[] = { - OPT_BOOLEAN('f', "no-fp", &nofp, "Skip frame pointer validation"), - OPT_END(), - }; - - argc = parse_options(argc, argv, options, check_usage, 0); + argc = parse_options(argc, argv, check_options, check_usage, 0);

if (argc != 1) - usage_with_options(check_usage, options); + usage_with_options(check_usage, check_options);

objname = argv[0];

- file.elf = elf_open(objname); - if (!file.elf) { - fprintf(stderr, "error reading elf file %s\n", objname); - return 1; - } - - INIT_LIST_HEAD(&file.insn_list); - hash_init(file.insn_hash); - file.whitelist = find_section_by_name(file.elf, ".discard.func_stack_frame_non_standard"); - file.rodata = find_section_by_name(file.elf, ".rodata"); - file.ignore_unreachables = false; - file.c_file = find_section_by_name(file.elf, ".comment"); - - ret = decode_sections(&file); - if (ret < 0) - goto out; - warnings += ret; - - ret = validate_functions(&file); - if (ret < 0) - goto out; - warnings += ret; - - ret = validate_uncallable_instructions(&file); - if (ret < 0) - goto out; - warnings += ret; - -out: - cleanup(&file); - - /* ignore warnings for now until we get all the code cleaned up */ - if (ret || warnings) - return 0; - return 0; + return check(objname, nofp); } diff --git a/tools/objtool/check.c b/tools/objtool/check.c new file mode 100644 index 000000000000..b7a0af57a43d --- /dev/null +++ b/tools/objtool/check.c @@ -0,0 +1,1327 @@ +/* + * Copyright (C) 2015-2017 Josh Poimboeuf jpoimboe@redhat.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ + +#include <string.h> +#include <stdlib.h> + +#include "check.h" +#include "elf.h" +#include "special.h" +#include "arch.h" +#include "warn.h" + +#include <linux/hashtable.h> + +#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) + +#define STATE_FP_SAVED 0x1 +#define STATE_FP_SETUP 0x2 +#define STATE_FENTRY 0x4 + +struct alternative { + struct list_head list; + struct instruction *insn; +}; + +const char *objname; +static bool nofp; + +static struct instruction *find_insn(struct objtool_file *file, + struct section *sec, unsigned long offset) +{ + struct instruction *insn; + + hash_for_each_possible(file->insn_hash, insn, hash, offset) + if (insn->sec == sec && insn->offset == offset) + return insn; + + return NULL; +} + +static struct instruction *next_insn_same_sec(struct objtool_file *file, + struct instruction *insn) +{ + struct instruction *next = list_next_entry(insn, list); + + if (&next->list == &file->insn_list || next->sec != insn->sec) + return NULL; + + return next; +} + +static bool gcov_enabled(struct objtool_file *file) +{ + struct section *sec; + struct symbol *sym; + + list_for_each_entry(sec, &file->elf->sections, list) + list_for_each_entry(sym, &sec->symbol_list, list) + if (!strncmp(sym->name, "__gcov_.", 8)) + return true; + + return false; +} + +#define for_each_insn(file, insn) \ + list_for_each_entry(insn, &file->insn_list, list) + +#define func_for_each_insn(file, func, insn) \ + for (insn = find_insn(file, func->sec, func->offset); \ + insn && &insn->list != &file->insn_list && \ + insn->sec == func->sec && \ + insn->offset < func->offset + func->len; \ + insn = list_next_entry(insn, list)) + +#define func_for_each_insn_continue_reverse(file, func, insn) \ + for (insn = list_prev_entry(insn, list); \ + &insn->list != &file->insn_list && \ + insn->sec == func->sec && insn->offset >= func->offset; \ + insn = list_prev_entry(insn, list)) + +#define sec_for_each_insn_from(file, insn) \ + for (; insn; insn = next_insn_same_sec(file, insn)) + + +/* + * Check if the function has been manually whitelisted with the + * STACK_FRAME_NON_STANDARD macro, or if it should be automatically whitelisted + * due to its use of a context switching instruction. + */ +static bool ignore_func(struct objtool_file *file, struct symbol *func) +{ + struct rela *rela; + struct instruction *insn; + + /* check for STACK_FRAME_NON_STANDARD */ + if (file->whitelist && file->whitelist->rela) + list_for_each_entry(rela, &file->whitelist->rela->rela_list, list) { + if (rela->sym->type == STT_SECTION && + rela->sym->sec == func->sec && + rela->addend == func->offset) + return true; + if (rela->sym->type == STT_FUNC && rela->sym == func) + return true; + } + + /* check if it has a context switching instruction */ + func_for_each_insn(file, func, insn) + if (insn->type == INSN_CONTEXT_SWITCH) + return true; + + return false; +} + +/* + * This checks to see if the given function is a "noreturn" function. + * + * For global functions which are outside the scope of this object file, we + * have to keep a manual list of them. + * + * For local functions, we have to detect them manually by simply looking for + * the lack of a return instruction. + * + * Returns: + * -1: error + * 0: no dead end + * 1: dead end + */ +static int __dead_end_function(struct objtool_file *file, struct symbol *func, + int recursion) +{ + int i; + struct instruction *insn; + bool empty = true; + + /* + * Unfortunately these have to be hard coded because the noreturn + * attribute isn't provided in ELF data. + */ + static const char * const global_noreturns[] = { + "__stack_chk_fail", + "panic", + "do_exit", + "do_task_dead", + "__module_put_and_exit", + "complete_and_exit", + "kvm_spurious_fault", + "__reiserfs_panic", + "lbug_with_loc" + }; + + if (func->bind == STB_WEAK) + return 0; + + if (func->bind == STB_GLOBAL) + for (i = 0; i < ARRAY_SIZE(global_noreturns); i++) + if (!strcmp(func->name, global_noreturns[i])) + return 1; + + if (!func->sec) + return 0; + + func_for_each_insn(file, func, insn) { + empty = false; + + if (insn->type == INSN_RETURN) + return 0; + } + + if (empty) + return 0; + + /* + * A function can have a sibling call instead of a return. In that + * case, the function's dead-end status depends on whether the target + * of the sibling call returns. + */ + func_for_each_insn(file, func, insn) { + if (insn->sec != func->sec || + insn->offset >= func->offset + func->len) + break; + + if (insn->type == INSN_JUMP_UNCONDITIONAL) { + struct instruction *dest = insn->jump_dest; + struct symbol *dest_func; + + if (!dest) + /* sibling call to another file */ + return 0; + + if (dest->sec != func->sec || + dest->offset < func->offset || + dest->offset >= func->offset + func->len) { + /* local sibling call */ + dest_func = find_symbol_by_offset(dest->sec, + dest->offset); + if (!dest_func) + continue; + + if (recursion == 5) { + WARN_FUNC("infinite recursion (objtool bug!)", + dest->sec, dest->offset); + return -1; + } + + return __dead_end_function(file, dest_func, + recursion + 1); + } + } + + if (insn->type == INSN_JUMP_DYNAMIC && list_empty(&insn->alts)) + /* sibling call */ + return 0; + } + + return 1; +} + +static int dead_end_function(struct objtool_file *file, struct symbol *func) +{ + return __dead_end_function(file, func, 0); +} + +/* + * Call the arch-specific instruction decoder for all the instructions and add + * them to the global instruction list. + */ +static int decode_instructions(struct objtool_file *file) +{ + struct section *sec; + struct symbol *func; + unsigned long offset; + struct instruction *insn; + int ret; + + list_for_each_entry(sec, &file->elf->sections, list) { + + if (!(sec->sh.sh_flags & SHF_EXECINSTR)) + continue; + + for (offset = 0; offset < sec->len; offset += insn->len) { + insn = malloc(sizeof(*insn)); + memset(insn, 0, sizeof(*insn)); + + INIT_LIST_HEAD(&insn->alts); + insn->sec = sec; + insn->offset = offset; + + ret = arch_decode_instruction(file->elf, sec, offset, + sec->len - offset, + &insn->len, &insn->type, + &insn->immediate); + if (ret) + return ret; + + if (!insn->type || insn->type > INSN_LAST) { + WARN_FUNC("invalid instruction type %d", + insn->sec, insn->offset, insn->type); + return -1; + } + + hash_add(file->insn_hash, &insn->hash, insn->offset); + list_add_tail(&insn->list, &file->insn_list); + } + + list_for_each_entry(func, &sec->symbol_list, list) { + if (func->type != STT_FUNC) + continue; + + if (!find_insn(file, sec, func->offset)) { + WARN("%s(): can't find starting instruction", + func->name); + return -1; + } + + func_for_each_insn(file, func, insn) + if (!insn->func) + insn->func = func; + } + } + + return 0; +} + +/* + * Find all uses of the unreachable() macro, which are code path dead ends. + */ +static int add_dead_ends(struct objtool_file *file) +{ + struct section *sec; + struct rela *rela; + struct instruction *insn; + bool found; + + sec = find_section_by_name(file->elf, ".rela__unreachable"); + if (!sec) + return 0; + + list_for_each_entry(rela, &sec->rela_list, list) { + if (rela->sym->type != STT_SECTION) { + WARN("unexpected relocation symbol type in .rela__unreachable"); + return -1; + } + insn = find_insn(file, rela->sym->sec, rela->addend); + if (insn) + insn = list_prev_entry(insn, list); + else if (rela->addend == rela->sym->sec->len) { + found = false; + list_for_each_entry_reverse(insn, &file->insn_list, list) { + if (insn->sec == rela->sym->sec) { + found = true; + break; + } + } + + if (!found) { + WARN("can't find unreachable insn at %s+0x%x", + rela->sym->sec->name, rela->addend); + return -1; + } + } else { + WARN("can't find unreachable insn at %s+0x%x", + rela->sym->sec->name, rela->addend); + return -1; + } + + insn->dead_end = true; + } + + return 0; +} + +/* + * Warnings shouldn't be reported for ignored functions. + */ +static void add_ignores(struct objtool_file *file) +{ + struct instruction *insn; + struct section *sec; + struct symbol *func; + + list_for_each_entry(sec, &file->elf->sections, list) { + list_for_each_entry(func, &sec->symbol_list, list) { + if (func->type != STT_FUNC) + continue; + + if (!ignore_func(file, func)) + continue; + + func_for_each_insn(file, func, insn) + insn->visited = true; + } + } +} + +/* + * FIXME: For now, just ignore any alternatives which add retpolines. This is + * a temporary hack, as it doesn't allow ORC to unwind from inside a retpoline. + * But it at least allows objtool to understand the control flow *around* the + * retpoline. + */ +static int add_nospec_ignores(struct objtool_file *file) +{ + struct section *sec; + struct rela *rela; + struct instruction *insn; + + sec = find_section_by_name(file->elf, ".rela.discard.nospec"); + if (!sec) + return 0; + + list_for_each_entry(rela, &sec->rela_list, list) { + if (rela->sym->type != STT_SECTION) { + WARN("unexpected relocation symbol type in %s", sec->name); + return -1; + } + + insn = find_insn(file, rela->sym->sec, rela->addend); + if (!insn) { + WARN("bad .discard.nospec entry"); + return -1; + } + + insn->ignore_alts = true; + } + + return 0; +} + +/* + * Find the destination instructions for all jumps. + */ +static int add_jump_destinations(struct objtool_file *file) +{ + struct instruction *insn; + struct rela *rela; + struct section *dest_sec; + unsigned long dest_off; + + for_each_insn(file, insn) { + if (insn->type != INSN_JUMP_CONDITIONAL && + insn->type != INSN_JUMP_UNCONDITIONAL) + continue; + + /* skip ignores */ + if (insn->visited) + continue; + + rela = find_rela_by_dest_range(insn->sec, insn->offset, + insn->len); + if (!rela) { + dest_sec = insn->sec; + dest_off = insn->offset + insn->len + insn->immediate; + } else if (rela->sym->type == STT_SECTION) { + dest_sec = rela->sym->sec; + dest_off = rela->addend + 4; + } else if (rela->sym->sec->idx) { + dest_sec = rela->sym->sec; + dest_off = rela->sym->sym.st_value + rela->addend + 4; + } else if (strstr(rela->sym->name, "_indirect_thunk_")) { + /* + * Retpoline jumps are really dynamic jumps in + * disguise, so convert them accordingly. + */ + insn->type = INSN_JUMP_DYNAMIC; + continue; + } else { + /* sibling call */ + insn->jump_dest = 0; + continue; + } + + insn->jump_dest = find_insn(file, dest_sec, dest_off); + if (!insn->jump_dest) { + + /* + * This is a special case where an alt instruction + * jumps past the end of the section. These are + * handled later in handle_group_alt(). + */ + if (!strcmp(insn->sec->name, ".altinstr_replacement")) + continue; + + WARN_FUNC("can't find jump dest instruction at %s+0x%lx", + insn->sec, insn->offset, dest_sec->name, + dest_off); + return -1; + } + } + + return 0; +} + +/* + * Find the destination instructions for all calls. + */ +static int add_call_destinations(struct objtool_file *file) +{ + struct instruction *insn; + unsigned long dest_off; + struct rela *rela; + + for_each_insn(file, insn) { + if (insn->type != INSN_CALL) + continue; + + rela = find_rela_by_dest_range(insn->sec, insn->offset, + insn->len); + if (!rela) { + dest_off = insn->offset + insn->len + insn->immediate; + insn->call_dest = find_symbol_by_offset(insn->sec, + dest_off); + /* + * FIXME: Thanks to retpolines, it's now considered + * normal for a function to call within itself. So + * disable this warning for now. + */ +#if 0 + if (!insn->call_dest) { + WARN_FUNC("can't find call dest symbol at offset 0x%lx", + insn->sec, insn->offset, dest_off); + return -1; + } +#endif + } else if (rela->sym->type == STT_SECTION) { + insn->call_dest = find_symbol_by_offset(rela->sym->sec, + rela->addend+4); + if (!insn->call_dest || + insn->call_dest->type != STT_FUNC) { + WARN_FUNC("can't find call dest symbol at %s+0x%x", + insn->sec, insn->offset, + rela->sym->sec->name, + rela->addend + 4); + return -1; + } + } else + insn->call_dest = rela->sym; + } + + return 0; +} + +/* + * The .alternatives section requires some extra special care, over and above + * what other special sections require: + * + * 1. Because alternatives are patched in-place, we need to insert a fake jump + * instruction at the end so that validate_branch() skips all the original + * replaced instructions when validating the new instruction path. + * + * 2. An added wrinkle is that the new instruction length might be zero. In + * that case the old instructions are replaced with noops. We simulate that + * by creating a fake jump as the only new instruction. + * + * 3. In some cases, the alternative section includes an instruction which + * conditionally jumps to the _end_ of the entry. We have to modify these + * jumps' destinations to point back to .text rather than the end of the + * entry in .altinstr_replacement. + * + * 4. It has been requested that we don't validate the !POPCNT feature path + * which is a "very very small percentage of machines". + */ +static int handle_group_alt(struct objtool_file *file, + struct special_alt *special_alt, + struct instruction *orig_insn, + struct instruction **new_insn) +{ + struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump; + unsigned long dest_off; + + last_orig_insn = NULL; + insn = orig_insn; + sec_for_each_insn_from(file, insn) { + if (insn->offset >= special_alt->orig_off + special_alt->orig_len) + break; + + if (special_alt->skip_orig) + insn->type = INSN_NOP; + + insn->alt_group = true; + last_orig_insn = insn; + } + + if (!next_insn_same_sec(file, last_orig_insn)) { + WARN("%s: don't know how to handle alternatives at end of section", + special_alt->orig_sec->name); + return -1; + } + + fake_jump = malloc(sizeof(*fake_jump)); + if (!fake_jump) { + WARN("malloc failed"); + return -1; + } + memset(fake_jump, 0, sizeof(*fake_jump)); + INIT_LIST_HEAD(&fake_jump->alts); + fake_jump->sec = special_alt->new_sec; + fake_jump->offset = -1; + fake_jump->type = INSN_JUMP_UNCONDITIONAL; + fake_jump->jump_dest = list_next_entry(last_orig_insn, list); + + if (!special_alt->new_len) { + *new_insn = fake_jump; + return 0; + } + + last_new_insn = NULL; + insn = *new_insn; + sec_for_each_insn_from(file, insn) { + if (insn->offset >= special_alt->new_off + special_alt->new_len) + break; + + last_new_insn = insn; + + if (insn->type != INSN_JUMP_CONDITIONAL && + insn->type != INSN_JUMP_UNCONDITIONAL) + continue; + + if (!insn->immediate) + continue; + + dest_off = insn->offset + insn->len + insn->immediate; + if (dest_off == special_alt->new_off + special_alt->new_len) + insn->jump_dest = fake_jump; + + if (!insn->jump_dest) { + WARN_FUNC("can't find alternative jump destination", + insn->sec, insn->offset); + return -1; + } + } + + if (!last_new_insn) { + WARN_FUNC("can't find last new alternative instruction", + special_alt->new_sec, special_alt->new_off); + return -1; + } + + list_add(&fake_jump->list, &last_new_insn->list); + + return 0; +} + +/* + * A jump table entry can either convert a nop to a jump or a jump to a nop. + * If the original instruction is a jump, make the alt entry an effective nop + * by just skipping the original instruction. + */ +static int handle_jump_alt(struct objtool_file *file, + struct special_alt *special_alt, + struct instruction *orig_insn, + struct instruction **new_insn) +{ + if (orig_insn->type == INSN_NOP) + return 0; + + if (orig_insn->type != INSN_JUMP_UNCONDITIONAL) { + WARN_FUNC("unsupported instruction at jump label", + orig_insn->sec, orig_insn->offset); + return -1; + } + + *new_insn = list_next_entry(orig_insn, list); + return 0; +} + +/* + * Read all the special sections which have alternate instructions which can be + * patched in or redirected to at runtime. Each instruction having alternate + * instruction(s) has them added to its insn->alts list, which will be + * traversed in validate_branch(). + */ +static int add_special_section_alts(struct objtool_file *file) +{ + struct list_head special_alts; + struct instruction *orig_insn, *new_insn; + struct special_alt *special_alt, *tmp; + struct alternative *alt; + int ret; + + ret = special_get_alts(file->elf, &special_alts); + if (ret) + return ret; + + list_for_each_entry_safe(special_alt, tmp, &special_alts, list) { + orig_insn = find_insn(file, special_alt->orig_sec, + special_alt->orig_off); + if (!orig_insn) { + WARN_FUNC("special: can't find orig instruction", + special_alt->orig_sec, special_alt->orig_off); + ret = -1; + goto out; + } + + /* Ignore retpoline alternatives. */ + if (orig_insn->ignore_alts) + continue; + + new_insn = NULL; + if (!special_alt->group || special_alt->new_len) { + new_insn = find_insn(file, special_alt->new_sec, + special_alt->new_off); + if (!new_insn) { + WARN_FUNC("special: can't find new instruction", + special_alt->new_sec, + special_alt->new_off); + ret = -1; + goto out; + } + } + + if (special_alt->group) { + ret = handle_group_alt(file, special_alt, orig_insn, + &new_insn); + if (ret) + goto out; + } else if (special_alt->jump_or_nop) { + ret = handle_jump_alt(file, special_alt, orig_insn, + &new_insn); + if (ret) + goto out; + } + + alt = malloc(sizeof(*alt)); + if (!alt) { + WARN("malloc failed"); + ret = -1; + goto out; + } + + alt->insn = new_insn; + list_add_tail(&alt->list, &orig_insn->alts); + + list_del(&special_alt->list); + free(special_alt); + } + +out: + return ret; +} + +static int add_switch_table(struct objtool_file *file, struct symbol *func, + struct instruction *insn, struct rela *table, + struct rela *next_table) +{ + struct rela *rela = table; + struct instruction *alt_insn; + struct alternative *alt; + + list_for_each_entry_from(rela, &file->rodata->rela->rela_list, list) { + if (rela == next_table) + break; + + if (rela->sym->sec != insn->sec || + rela->addend <= func->offset || + rela->addend >= func->offset + func->len) + break; + + alt_insn = find_insn(file, insn->sec, rela->addend); + if (!alt_insn) { + WARN("%s: can't find instruction at %s+0x%x", + file->rodata->rela->name, insn->sec->name, + rela->addend); + return -1; + } + + alt = malloc(sizeof(*alt)); + if (!alt) { + WARN("malloc failed"); + return -1; + } + + alt->insn = alt_insn; + list_add_tail(&alt->list, &insn->alts); + } + + return 0; +} + +/* + * find_switch_table() - Given a dynamic jump, find the switch jump table in + * .rodata associated with it. + * + * There are 3 basic patterns: + * + * 1. jmpq *[rodata addr](,%reg,8) + * + * This is the most common case by far. It jumps to an address in a simple + * jump table which is stored in .rodata. + * + * 2. jmpq *[rodata addr](%rip) + * + * This is caused by a rare GCC quirk, currently only seen in three driver + * functions in the kernel, only with certain obscure non-distro configs. + * + * As part of an optimization, GCC makes a copy of an existing switch jump + * table, modifies it, and then hard-codes the jump (albeit with an indirect + * jump) to use a single entry in the table. The rest of the jump table and + * some of its jump targets remain as dead code. + * + * In such a case we can just crudely ignore all unreachable instruction + * warnings for the entire object file. Ideally we would just ignore them + * for the function, but that would require redesigning the code quite a + * bit. And honestly that's just not worth doing: unreachable instruction + * warnings are of questionable value anyway, and this is such a rare issue. + * + * 3. mov [rodata addr],%reg1 + * ... some instructions ... + * jmpq *(%reg1,%reg2,8) + * + * This is a fairly uncommon pattern which is new for GCC 6. As of this + * writing, there are 11 occurrences of it in the allmodconfig kernel. + * + * TODO: Once we have DWARF CFI and smarter instruction decoding logic, + * ensure the same register is used in the mov and jump instructions. + */ +static struct rela *find_switch_table(struct objtool_file *file, + struct symbol *func, + struct instruction *insn) +{ + struct rela *text_rela, *rodata_rela; + struct instruction *orig_insn = insn; + + text_rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len); + if (text_rela && text_rela->sym == file->rodata->sym) { + /* case 1 */ + rodata_rela = find_rela_by_dest(file->rodata, + text_rela->addend); + if (rodata_rela) + return rodata_rela; + + /* case 2 */ + rodata_rela = find_rela_by_dest(file->rodata, + text_rela->addend + 4); + if (!rodata_rela) + return NULL; + file->ignore_unreachables = true; + return rodata_rela; + } + + /* case 3 */ + func_for_each_insn_continue_reverse(file, func, insn) { + if (insn->type == INSN_JUMP_DYNAMIC) + break; + + /* allow small jumps within the range */ + if (insn->type == INSN_JUMP_UNCONDITIONAL && + insn->jump_dest && + (insn->jump_dest->offset <= insn->offset || + insn->jump_dest->offset > orig_insn->offset)) + break; + + /* look for a relocation which references .rodata */ + text_rela = find_rela_by_dest_range(insn->sec, insn->offset, + insn->len); + if (!text_rela || text_rela->sym != file->rodata->sym) + continue; + + /* + * Make sure the .rodata address isn't associated with a + * symbol. gcc jump tables are anonymous data. + */ + if (find_symbol_containing(file->rodata, text_rela->addend)) + continue; + + return find_rela_by_dest(file->rodata, text_rela->addend); + } + + return NULL; +} + +static int add_func_switch_tables(struct objtool_file *file, + struct symbol *func) +{ + struct instruction *insn, *prev_jump = NULL; + struct rela *rela, *prev_rela = NULL; + int ret; + + func_for_each_insn(file, func, insn) { + if (insn->type != INSN_JUMP_DYNAMIC) + continue; + + rela = find_switch_table(file, func, insn); + if (!rela) + continue; + + /* + * We found a switch table, but we don't know yet how big it + * is. Don't add it until we reach the end of the function or + * the beginning of another switch table in the same function. + */ + if (prev_jump) { + ret = add_switch_table(file, func, prev_jump, prev_rela, + rela); + if (ret) + return ret; + } + + prev_jump = insn; + prev_rela = rela; + } + + if (prev_jump) { + ret = add_switch_table(file, func, prev_jump, prev_rela, NULL); + if (ret) + return ret; + } + + return 0; +} + +/* + * For some switch statements, gcc generates a jump table in the .rodata + * section which contains a list of addresses within the function to jump to. + * This finds these jump tables and adds them to the insn->alts lists. + */ +static int add_switch_table_alts(struct objtool_file *file) +{ + struct section *sec; + struct symbol *func; + int ret; + + if (!file->rodata || !file->rodata->rela) + return 0; + + list_for_each_entry(sec, &file->elf->sections, list) { + list_for_each_entry(func, &sec->symbol_list, list) { + if (func->type != STT_FUNC) + continue; + + ret = add_func_switch_tables(file, func); + if (ret) + return ret; + } + } + + return 0; +} + +static int decode_sections(struct objtool_file *file) +{ + int ret; + + ret = decode_instructions(file); + if (ret) + return ret; + + ret = add_dead_ends(file); + if (ret) + return ret; + + add_ignores(file); + + ret = add_nospec_ignores(file); + if (ret) + return ret; + + ret = add_jump_destinations(file); + if (ret) + return ret; + + ret = add_call_destinations(file); + if (ret) + return ret; + + ret = add_special_section_alts(file); + if (ret) + return ret; + + ret = add_switch_table_alts(file); + if (ret) + return ret; + + return 0; +} + +static bool is_fentry_call(struct instruction *insn) +{ + if (insn->type == INSN_CALL && + insn->call_dest->type == STT_NOTYPE && + !strcmp(insn->call_dest->name, "__fentry__")) + return true; + + return false; +} + +static bool has_modified_stack_frame(struct instruction *insn) +{ + return (insn->state & STATE_FP_SAVED) || + (insn->state & STATE_FP_SETUP); +} + +static bool has_valid_stack_frame(struct instruction *insn) +{ + return (insn->state & STATE_FP_SAVED) && + (insn->state & STATE_FP_SETUP); +} + +static unsigned int frame_state(unsigned long state) +{ + return (state & (STATE_FP_SAVED | STATE_FP_SETUP)); +} + +/* + * Follow the branch starting at the given instruction, and recursively follow + * any other branches (jumps). Meanwhile, track the frame pointer state at + * each instruction and validate all the rules described in + * tools/objtool/Documentation/stack-validation.txt. + */ +static int validate_branch(struct objtool_file *file, + struct instruction *first, unsigned char first_state) +{ + struct alternative *alt; + struct instruction *insn; + struct section *sec; + struct symbol *func = NULL; + unsigned char state; + int ret; + + insn = first; + sec = insn->sec; + state = first_state; + + if (insn->alt_group && list_empty(&insn->alts)) { + WARN_FUNC("don't know how to handle branch to middle of alternative instruction group", + sec, insn->offset); + return 1; + } + + while (1) { + if (file->c_file && insn->func) { + if (func && func != insn->func) { + WARN("%s() falls through to next function %s()", + func->name, insn->func->name); + return 1; + } + + func = insn->func; + } + + if (insn->visited) { + if (frame_state(insn->state) != frame_state(state)) { + WARN_FUNC("frame pointer state mismatch", + sec, insn->offset); + return 1; + } + + return 0; + } + + insn->visited = true; + insn->state = state; + + list_for_each_entry(alt, &insn->alts, list) { + ret = validate_branch(file, alt->insn, state); + if (ret) + return 1; + } + + switch (insn->type) { + + case INSN_FP_SAVE: + if (!nofp) { + if (state & STATE_FP_SAVED) { + WARN_FUNC("duplicate frame pointer save", + sec, insn->offset); + return 1; + } + state |= STATE_FP_SAVED; + } + break; + + case INSN_FP_SETUP: + if (!nofp) { + if (state & STATE_FP_SETUP) { + WARN_FUNC("duplicate frame pointer setup", + sec, insn->offset); + return 1; + } + state |= STATE_FP_SETUP; + } + break; + + case INSN_FP_RESTORE: + if (!nofp) { + if (has_valid_stack_frame(insn)) + state &= ~STATE_FP_SETUP; + + state &= ~STATE_FP_SAVED; + } + break; + + case INSN_RETURN: + if (!nofp && has_modified_stack_frame(insn)) { + WARN_FUNC("return without frame pointer restore", + sec, insn->offset); + return 1; + } + return 0; + + case INSN_CALL: + if (is_fentry_call(insn)) { + state |= STATE_FENTRY; + break; + } + + ret = dead_end_function(file, insn->call_dest); + if (ret == 1) + return 0; + if (ret == -1) + return 1; + + /* fallthrough */ + case INSN_CALL_DYNAMIC: + if (!nofp && !has_valid_stack_frame(insn)) { + WARN_FUNC("call without frame pointer save/setup", + sec, insn->offset); + return 1; + } + break; + + case INSN_JUMP_CONDITIONAL: + case INSN_JUMP_UNCONDITIONAL: + if (insn->jump_dest) { + ret = validate_branch(file, insn->jump_dest, + state); + if (ret) + return 1; + } else if (has_modified_stack_frame(insn)) { + WARN_FUNC("sibling call from callable instruction with changed frame pointer", + sec, insn->offset); + return 1; + } /* else it's a sibling call */ + + if (insn->type == INSN_JUMP_UNCONDITIONAL) + return 0; + + break; + + case INSN_JUMP_DYNAMIC: + if (list_empty(&insn->alts) && + has_modified_stack_frame(insn)) { + WARN_FUNC("sibling call from callable instruction with changed frame pointer", + sec, insn->offset); + return 1; + } + + return 0; + + default: + break; + } + + if (insn->dead_end) + return 0; + + insn = next_insn_same_sec(file, insn); + if (!insn) { + WARN("%s: unexpected end of section", sec->name); + return 1; + } + } + + return 0; +} + +static bool is_kasan_insn(struct instruction *insn) +{ + return (insn->type == INSN_CALL && + !strcmp(insn->call_dest->name, "__asan_handle_no_return")); +} + +static bool is_ubsan_insn(struct instruction *insn) +{ + return (insn->type == INSN_CALL && + !strcmp(insn->call_dest->name, + "__ubsan_handle_builtin_unreachable")); +} + +static bool ignore_unreachable_insn(struct symbol *func, + struct instruction *insn) +{ + int i; + + if (insn->type == INSN_NOP) + return true; + + /* + * Check if this (or a subsequent) instruction is related to + * CONFIG_UBSAN or CONFIG_KASAN. + * + * End the search at 5 instructions to avoid going into the weeds. + */ + for (i = 0; i < 5; i++) { + + if (is_kasan_insn(insn) || is_ubsan_insn(insn)) + return true; + + if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest) { + insn = insn->jump_dest; + continue; + } + + if (insn->offset + insn->len >= func->offset + func->len) + break; + insn = list_next_entry(insn, list); + } + + return false; +} + +static int validate_functions(struct objtool_file *file) +{ + struct section *sec; + struct symbol *func; + struct instruction *insn; + int ret, warnings = 0; + + list_for_each_entry(sec, &file->elf->sections, list) { + list_for_each_entry(func, &sec->symbol_list, list) { + if (func->type != STT_FUNC) + continue; + + insn = find_insn(file, sec, func->offset); + if (!insn) + continue; + + ret = validate_branch(file, insn, 0); + warnings += ret; + } + } + + list_for_each_entry(sec, &file->elf->sections, list) { + list_for_each_entry(func, &sec->symbol_list, list) { + if (func->type != STT_FUNC) + continue; + + func_for_each_insn(file, func, insn) { + if (insn->visited) + continue; + + insn->visited = true; + + if (file->ignore_unreachables || warnings || + ignore_unreachable_insn(func, insn)) + continue; + + /* + * gcov produces a lot of unreachable + * instructions. If we get an unreachable + * warning and the file has gcov enabled, just + * ignore it, and all other such warnings for + * the file. + */ + if (!file->ignore_unreachables && + gcov_enabled(file)) { + file->ignore_unreachables = true; + continue; + } + + WARN_FUNC("function has unreachable instruction", insn->sec, insn->offset); + warnings++; + } + } + } + + return warnings; +} + +static int validate_uncallable_instructions(struct objtool_file *file) +{ + struct instruction *insn; + int warnings = 0; + + for_each_insn(file, insn) { + if (!insn->visited && insn->type == INSN_RETURN) { + + /* + * Don't warn about call instructions in unvisited + * retpoline alternatives. + */ + if (!strcmp(insn->sec->name, ".altinstr_replacement")) + continue; + + WARN_FUNC("return instruction outside of a callable function", + insn->sec, insn->offset); + warnings++; + } + } + + return warnings; +} + +static void cleanup(struct objtool_file *file) +{ + struct instruction *insn, *tmpinsn; + struct alternative *alt, *tmpalt; + + list_for_each_entry_safe(insn, tmpinsn, &file->insn_list, list) { + list_for_each_entry_safe(alt, tmpalt, &insn->alts, list) { + list_del(&alt->list); + free(alt); + } + list_del(&insn->list); + hash_del(&insn->hash); + free(insn); + } + elf_close(file->elf); +} + +int check(const char *_objname, bool _nofp) +{ + struct objtool_file file; + int ret, warnings = 0; + + objname = _objname; + nofp = _nofp; + + file.elf = elf_open(objname); + if (!file.elf) { + fprintf(stderr, "error reading elf file %s\n", objname); + return 1; + } + + INIT_LIST_HEAD(&file.insn_list); + hash_init(file.insn_hash); + file.whitelist = find_section_by_name(file.elf, ".discard.func_stack_frame_non_standard"); + file.rodata = find_section_by_name(file.elf, ".rodata"); + file.ignore_unreachables = false; + file.c_file = find_section_by_name(file.elf, ".comment"); + + ret = decode_sections(&file); + if (ret < 0) + goto out; + warnings += ret; + + ret = validate_functions(&file); + if (ret < 0) + goto out; + warnings += ret; + + ret = validate_uncallable_instructions(&file); + if (ret < 0) + goto out; + warnings += ret; + +out: + cleanup(&file); + + /* ignore warnings for now until we get all the code cleaned up */ + if (ret || warnings) + return 0; + return 0; +} diff --git a/tools/objtool/check.h b/tools/objtool/check.h new file mode 100644 index 000000000000..aca248a049e0 --- /dev/null +++ b/tools/objtool/check.h @@ -0,0 +1,51 @@ +/* + * Copyright (C) 2017 Josh Poimboeuf jpoimboe@redhat.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ + +#ifndef _CHECK_H +#define _CHECK_H + +#include <stdbool.h> +#include "elf.h" +#include "arch.h" +#include <linux/hashtable.h> + +struct instruction { + struct list_head list; + struct hlist_node hash; + struct section *sec; + unsigned long offset; + unsigned int len, state; + unsigned char type; + unsigned long immediate; + bool alt_group, visited, dead_end, ignore_alts; + struct symbol *call_dest; + struct instruction *jump_dest; + struct list_head alts; + struct symbol *func; +}; + +struct objtool_file { + struct elf *elf; + struct list_head insn_list; + DECLARE_HASHTABLE(insn_hash, 16); + struct section *rodata, *whitelist; + bool ignore_unreachables, c_file; +}; + +int check(const char *objname, bool nofp); + +#endif /* _CHECK_H */

From: Matthew Wilcox willy@linux.intel.com

commit b328daf3b7130098b105c18bdae694ddaad5b6e3 upstream.

I need the following functions for the radix tree:

bitmap_fill bitmap_empty bitmap_full

Copy the implementations from include/linux/bitmap.h

Signed-off-by: Matthew Wilcox willy@linux.intel.com Tested-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Cc: Konstantin Khlebnikov koct9i@gmail.com Cc: Ross Zwisler ross.zwisler@linux.intel.com Cc: Matthew Wilcox mawilcox@microsoft.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/include/linux/bitmap.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)

diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h index 43c1c5021e4b..eef41d500e9e 100644 --- a/tools/include/linux/bitmap.h +++ b/tools/include/linux/bitmap.h @@ -35,6 +35,32 @@ static inline void bitmap_zero(unsigned long *dst, int nbits) } }

+static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) +{ + unsigned int nlongs = BITS_TO_LONGS(nbits); + if (!small_const_nbits(nbits)) { + unsigned int len = (nlongs - 1) * sizeof(unsigned long); + memset(dst, 0xff, len); + } + dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); +} + +static inline int bitmap_empty(const unsigned long *src, unsigned nbits) +{ + if (small_const_nbits(nbits)) + return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); + + return find_first_bit(src, nbits) == nbits; +} + +static inline int bitmap_full(const unsigned long *src, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); + + return find_first_zero_bit(src, nbits) == nbits; +} + static inline int bitmap_weight(const unsigned long *src, int nbits) { if (small_const_nbits(nbits))

From: Arnaldo Carvalho de Melo acme@redhat.com

commit 192614010a5052fe92611c7076ef664fd9bb60e8 upstream.

To match the kernel headers structure, setting up things that are specific to gcc or to some specific version of gcc.

It gets included by linux/compiler.h when gcc is the compiler being used.

Cc: Adrian Hunter adrian.hunter@intel.com Cc: David Ahern dsahern@gmail.com Cc: Jiri Olsa jolsa@kernel.org Cc: Joe Perches joe@perches.com Cc: Namhyung Kim namhyung@kernel.org Cc: Wang Nan wangnan0@huawei.com Link: http://lkml.kernel.org/n/tip-fabcqfq4asodq9t158hcs8t3@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/include/linux/compiler-gcc.h | 14 ++++++++++++++ tools/include/linux/compiler.h | 10 +++++----- tools/perf/MANIFEST | 1 + 3 files changed, 20 insertions(+), 5 deletions(-) create mode 100644 tools/include/linux/compiler-gcc.h

diff --git a/tools/include/linux/compiler-gcc.h b/tools/include/linux/compiler-gcc.h new file mode 100644 index 000000000000..48af2f10a42d --- /dev/null +++ b/tools/include/linux/compiler-gcc.h @@ -0,0 +1,14 @@ +#ifndef _TOOLS_LINUX_COMPILER_H_ +#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead." +#endif + +/* + * Common definitions for all gcc versions go here. + */ +#define GCC_VERSION (__GNUC__ * 10000 \ + + __GNUC_MINOR__ * 100 \ + + __GNUC_PATCHLEVEL__) + +#if GCC_VERSION >= 70000 && !defined(__CHECKER__) +# define __fallthrough __attribute__ ((fallthrough)) +#endif diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index d94179f94caa..6326ede9aece 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -1,6 +1,10 @@ #ifndef _TOOLS_LINUX_COMPILER_H_ #define _TOOLS_LINUX_COMPILER_H_

+#ifdef __GNUC__ +#include <linux/compiler-gcc.h> +#endif + /* Optimization barrier */ /* The "volatile" is due to gcc bugs */ #define barrier() __asm__ __volatile__("": : :"memory") @@ -128,11 +132,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s

#ifndef __fallthrough -# if defined(__GNUC__) && __GNUC__ >= 7 -# define __fallthrough __attribute__ ((fallthrough)) -# else -# define __fallthrough -# endif +# define __fallthrough #endif

#endif /* _TOOLS_LINUX_COMPILER_H */ diff --git a/tools/perf/MANIFEST b/tools/perf/MANIFEST index a511e5f31e36..8672f835ae4e 100644 --- a/tools/perf/MANIFEST +++ b/tools/perf/MANIFEST @@ -61,6 +61,7 @@ tools/include/asm-generic/bitops.h tools/include/linux/atomic.h tools/include/linux/bitops.h tools/include/linux/compiler.h +tools/include/linux/compiler-gcc.h tools/include/linux/coresight-pmu.h tools/include/linux/filter.h tools/include/linux/hash.h

From: Arnaldo Carvalho de Melo acme@redhat.com

commit 4900653829175f60356efc279695bb23c59483c3 upstream.

From the kernel, get the gcc one and provide the fallback so that we can

continue build with other compilers, such as with clang.

Will be used by tools/arch/x86/include/asm/cmpxchg.h.

Cc: Adrian Hunter adrian.hunter@intel.com Cc: David Ahern dsahern@gmail.com Cc: Elena Reshetova elena.reshetova@intel.com Cc: Jiri Olsa jolsa@kernel.org Cc: Namhyung Kim namhyung@kernel.org Cc: Wang Nan wangnan0@huawei.com Link: http://lkml.kernel.org/n/tip-pecgz6efai4a9euuk4rxuotr@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/include/linux/compiler-gcc.h | 4 ++++ tools/include/linux/compiler.h | 4 ++++ 2 files changed, 8 insertions(+)

diff --git a/tools/include/linux/compiler-gcc.h b/tools/include/linux/compiler-gcc.h index 48af2f10a42d..616935f1ff56 100644 --- a/tools/include/linux/compiler-gcc.h +++ b/tools/include/linux/compiler-gcc.h @@ -12,3 +12,7 @@ #if GCC_VERSION >= 70000 && !defined(__CHECKER__) # define __fallthrough __attribute__ ((fallthrough)) #endif + +#if GCC_VERSION >= 40300 +# define __compiletime_error(message) __attribute__((error(message))) +#endif /* GCC_VERSION >= 40300 */ diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index 8de163b17c0d..c9e65e8faacd 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -5,6 +5,10 @@ #include <linux/compiler-gcc.h> #endif

+#ifndef __compiletime_error +# define __compiletime_error(message) +#endif + /* Optimization barrier */ /* The "volatile" is due to gcc bugs */ #define barrier() __asm__ __volatile__("": : :"memory")

From: Arnaldo Carvalho de Melo acme@redhat.com

commit eaa75b5117d52adf1efd3c6c3fb4bd8f97de648b upstream.

The kernel has it and some files we got from there would require us including the userland header for that, so add it conditionally.

Cc: Adrian Hunter adrian.hunter@intel.com Cc: David Ahern dsahern@gmail.com Cc: Elena Reshetova elena.reshetova@intel.com Cc: Jiri Olsa jolsa@kernel.org Cc: Namhyung Kim namhyung@kernel.org Cc: Wang Nan wangnan0@huawei.com Link: http://lkml.kernel.org/n/tip-gmwyal7c9vzzttlyk6u59rzn@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/include/linux/kernel.h | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/tools/include/linux/kernel.h b/tools/include/linux/kernel.h index 28607db02bd3..adb4d0147755 100644 --- a/tools/include/linux/kernel.h +++ b/tools/include/linux/kernel.h @@ -5,6 +5,10 @@ #include <stddef.h> #include <assert.h>

+#ifndef UINT_MAX +#define UINT_MAX (~0U) +#endif + #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))

#define PERF_ALIGN(x, a) __PERF_ALIGN_MASK(x, (typeof(x))(a)-1)

From: Jiri Olsa jolsa@kernel.org

commit abb26210a39522a6645bce3f438ed9a26bedb11b upstream.

The fixdep tool needs to be built before everything else, because it fixes every object dependency file.

We handle this currently by making all objects to depend on fixdep, which is error prone and is easily forgotten when new object is added.

Instead of this, this patch force fixdep tool to be built as the first target in the separate make session. This way we don't need to handle extra fixdep dependencies and we are certain there's no fixdep race with any parallel make job.

Committer notes:

Testing it:

Before:

$ rm -rf /tmp/build/perf/ ; mkdir -p /tmp/build/perf ; make -k O=/tmp/build/perf -C tools/perf install-bin make: Entering directory '/home/acme/git/linux/tools/perf' BUILD: Doing 'make -j4' parallel build

Auto-detecting system features: ... dwarf: [ on ] ... dwarf_getlocations: [ on ] ... glibc: [ on ] ... gtk2: [ on ] ... libaudit: [ on ] ... libbfd: [ on ] ... libelf: [ on ] ... libnuma: [ on ] ... numa_num_possible_cpus: [ on ] ... libperl: [ on ] ... libpython: [ on ] ... libslang: [ on ] ... libcrypto: [ on ] ... libunwind: [ on ] ... libdw-dwarf-unwind: [ on ] ... zlib: [ on ] ... lzma: [ on ] ... get_cpuid: [ on ] ... bpf: [ on ]

GEN /tmp/build/perf/common-cmds.h HOSTCC /tmp/build/perf/fixdep.o HOSTLD /tmp/build/perf/fixdep-in.o LINK /tmp/build/perf/fixdep MKDIR /tmp/build/perf/pmu-events/ HOSTCC /tmp/build/perf/pmu-events/json.o MKDIR /tmp/build/perf/pmu-events/ HOSTCC /tmp/build/perf/pmu-events/jsmn.o HOSTCC /tmp/build/perf/pmu-events/jevents.o HOSTLD /tmp/build/perf/pmu-events/jevents-in.o PERF_VERSION = 4.9.rc8.g868cd5 CC /tmp/build/perf/perf-read-vdso32 <SNIP>

After:

$ rm -rf /tmp/build/perf/ ; mkdir -p /tmp/build/perf ; make -k O=/tmp/build/perf -C tools/perf install-bin make: Entering directory '/home/acme/git/linux/tools/perf' BUILD: Doing 'make -j4' parallel build HOSTCC /tmp/build/perf/fixdep.o HOSTLD /tmp/build/perf/fixdep-in.o LINK /tmp/build/perf/fixdep

Auto-detecting system features: ... dwarf: [ on ] ... dwarf_getlocations: [ on ] ... glibc: [ on ] ... gtk2: [ on ] ... libaudit: [ on ] ... libbfd: [ on ] ... libelf: [ on ] ... libnuma: [ on ] ... numa_num_possible_cpus: [ on ] ... libperl: [ on ] ... libpython: [ on ] ... libslang: [ on ] ... libcrypto: [ on ] ... libunwind: [ on ] ... libdw-dwarf-unwind: [ on ] ... zlib: [ on ] ... lzma: [ on ] ... get_cpuid: [ on ] ... bpf: [ on ]

GEN /tmp/build/perf/common-cmds.h MKDIR /tmp/build/perf/fd/ CC /tmp/build/perf/fd/array.o LD /tmp/build/perf/fd/libapi-in.o MKDIR /tmp/build/perf/fs/ CC /tmp/build/perf/event-parse.o CC /tmp/build/perf/fs/fs.o PERF_VERSION = 4.9.rc8.g57a92f CC /tmp/build/perf/event-plugin.o MKDIR /tmp/build/perf/fs/ CC /tmp/build/perf/fs/tracing_path.o <SNIP>

Signed-off-by: Jiri Olsa jolsa@kernel.org Tested-by: Arnaldo Carvalho de Melo acme@redhat.com Cc: David Ahern dsahern@gmail.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra a.p.zijlstra@chello.nl Link: http://lkml.kernel.org/r/1481030331-31944-3-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/perf/Makefile.perf | 50 ++++++++++++++++++++++++++++++---------- 1 file changed, 38 insertions(+), 12 deletions(-)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 2b92ffef554b..7dde2618d677 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -177,6 +177,35 @@ ifeq ($(filter-out $(NON_CONFIG_TARGETS),$(MAKECMDGOALS)),) endif endif

+# The fixdep build - we force fixdep tool to be built as +# the first target in the separate make session not to be +# disturbed by any parallel make jobs. Once fixdep is done +# we issue the requested build with FIXDEP=1 variable. +# +# The fixdep build is disabled for $(NON_CONFIG_TARGETS) +# targets, because it's not necessary. + +ifdef FIXDEP + force_fixdep := 0 +else + force_fixdep := $(config) +endif + +export srctree OUTPUT RM CC CXX LD AR CFLAGS CXXFLAGS V BISON FLEX AWK +export HOSTCC HOSTLD HOSTAR + +include $(srctree)/tools/build/Makefile.include + +ifeq ($(force_fixdep),1) +goals := $(filter-out all sub-make, $(MAKECMDGOALS)) + +$(goals) all: sub-make + +sub-make: fixdep + $(Q)$(MAKE) FIXDEP=1 -f Makefile.perf $(goals) + +else # force_fixdep + # Set FEATURE_TESTS to 'all' so all possible feature checkers are executed. # Without this setting the output feature dump file misses some features, for # example, liberty. Select all checkers so we won't get an incomplete feature @@ -348,10 +377,6 @@ strip: $(PROGRAMS) $(OUTPUT)perf

PERF_IN := $(OUTPUT)perf-in.o

-export srctree OUTPUT RM CC LD AR CFLAGS V BISON FLEX AWK -export HOSTCC HOSTLD HOSTAR -include $(srctree)/tools/build/Makefile.include - JEVENTS := $(OUTPUT)pmu-events/jevents JEVENTS_IN := $(OUTPUT)pmu-events/jevents-in.o

@@ -470,7 +495,7 @@ $(OUTPUT)perf: $(PERFLIBS) $(PERF_IN) $(PMU_EVENTS_IN) $(LIBTRACEEVENT_DYNAMIC_L $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $(LIBTRACEEVENT_DYNAMIC_LIST_LDFLAGS) \ $(PERF_IN) $(PMU_EVENTS_IN) $(LIBS) -o $@

-$(GTK_IN): fixdep FORCE +$(GTK_IN): FORCE $(Q)$(MAKE) $(build)=gtk

$(OUTPUT)libperf-gtk.so: $(GTK_IN) $(PERFLIBS) @@ -515,7 +540,7 @@ endif __build-dir = $(subst $(OUTPUT),,$(dir $@)) build-dir = $(if $(__build-dir),$(__build-dir),.)

-prepare: $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)common-cmds.h fixdep archheaders +prepare: $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)common-cmds.h archheaders

$(OUTPUT)%.o: %.c prepare FORCE $(Q)$(MAKE) -f $(srctree)/tools/build/Makefile.build dir=$(build-dir) $@ @@ -555,7 +580,7 @@ $(patsubst perf-%,%.o,$(PROGRAMS)): $(wildcard */*.h)

LIBPERF_IN := $(OUTPUT)libperf-in.o

-$(LIBPERF_IN): prepare fixdep FORCE +$(LIBPERF_IN): prepare FORCE $(Q)$(MAKE) $(build)=libperf

$(LIB_FILE): $(LIBPERF_IN) @@ -563,10 +588,10 @@ $(LIB_FILE): $(LIBPERF_IN)

LIBTRACEEVENT_FLAGS += plugin_dir=$(plugindir_SQ)

-$(LIBTRACEEVENT): fixdep FORCE +$(LIBTRACEEVENT): FORCE $(Q)$(MAKE) -C $(TRACE_EVENT_DIR) $(LIBTRACEEVENT_FLAGS) O=$(OUTPUT) $(OUTPUT)libtraceevent.a

-libtraceevent_plugins: fixdep FORCE +libtraceevent_plugins: FORCE $(Q)$(MAKE) -C $(TRACE_EVENT_DIR) $(LIBTRACEEVENT_FLAGS) O=$(OUTPUT) plugins

$(LIBTRACEEVENT_DYNAMIC_LIST): libtraceevent_plugins @@ -579,21 +604,21 @@ $(LIBTRACEEVENT)-clean: install-traceevent-plugins: libtraceevent_plugins $(Q)$(MAKE) -C $(TRACE_EVENT_DIR) $(LIBTRACEEVENT_FLAGS) O=$(OUTPUT) install_plugins

-$(LIBAPI): fixdep FORCE +$(LIBAPI): FORCE $(Q)$(MAKE) -C $(LIB_DIR) O=$(OUTPUT) $(OUTPUT)libapi.a

$(LIBAPI)-clean: $(call QUIET_CLEAN, libapi) $(Q)$(MAKE) -C $(LIB_DIR) O=$(OUTPUT) clean >/dev/null

-$(LIBBPF): fixdep FORCE +$(LIBBPF): FORCE $(Q)$(MAKE) -C $(BPF_DIR) O=$(OUTPUT) $(OUTPUT)libbpf.a FEATURES_DUMP=$(FEATURE_DUMP_EXPORT)

$(LIBBPF)-clean: $(call QUIET_CLEAN, libbpf) $(Q)$(MAKE) -C $(BPF_DIR) O=$(OUTPUT) clean >/dev/null

-$(LIBSUBCMD): fixdep FORCE +$(LIBSUBCMD): FORCE $(Q)$(MAKE) -C $(SUBCMD_DIR) O=$(OUTPUT) $(OUTPUT)libsubcmd.a

$(LIBSUBCMD)-clean: @@ -790,3 +815,4 @@ FORCE: .PHONY: $(GIT-HEAD-PHONY) TAGS tags cscope FORCE prepare .PHONY: libtraceevent_plugins archheaders

+endif # force_fixdep

From: Arnaldo Carvalho de Melo acme@redhat.com

commit 67ef28794d7e30f33936d655f2951e8dcae7cd5a upstream.

We will need it to build tools/perf/trace/beauty/statx.h.

Cc: Adrian Hunter adrian.hunter@intel.com Cc: David Ahern dsahern@gmail.com Cc: Jiri Olsa jolsa@kernel.org Cc: Namhyung Kim namhyung@kernel.org Cc: Wang Nan wangnan0@huawei.com Link: http://lkml.kernel.org/n/tip-nin41ve2fa63lrfbdr6x57yr@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/include/linux/types.h | 1 + tools/include/uapi/linux/fcntl.h | 72 +++++++++++++ tools/include/uapi/linux/stat.h | 176 +++++++++++++++++++++++++++++++ tools/perf/MANIFEST | 2 + tools/perf/check-headers.sh | 2 + 5 files changed, 253 insertions(+) create mode 100644 tools/include/uapi/linux/fcntl.h create mode 100644 tools/include/uapi/linux/stat.h

diff --git a/tools/include/linux/types.h b/tools/include/linux/types.h index c24b3e3ae296..77a28a26a670 100644 --- a/tools/include/linux/types.h +++ b/tools/include/linux/types.h @@ -7,6 +7,7 @@

#define __SANE_USERSPACE_TYPES__ /* For PPC64, to get LL64 types */ #include <asm/types.h> +#include <asm/posix_types.h>

struct page; struct kmem_cache; diff --git a/tools/include/uapi/linux/fcntl.h b/tools/include/uapi/linux/fcntl.h new file mode 100644 index 000000000000..813afd6eee71 --- /dev/null +++ b/tools/include/uapi/linux/fcntl.h @@ -0,0 +1,72 @@ +#ifndef _UAPI_LINUX_FCNTL_H +#define _UAPI_LINUX_FCNTL_H + +#include <asm/fcntl.h> + +#define F_SETLEASE (F_LINUX_SPECIFIC_BASE + 0) +#define F_GETLEASE (F_LINUX_SPECIFIC_BASE + 1) + +/* + * Cancel a blocking posix lock; internal use only until we expose an + * asynchronous lock api to userspace: + */ +#define F_CANCELLK (F_LINUX_SPECIFIC_BASE + 5) + +/* Create a file descriptor with FD_CLOEXEC set. */ +#define F_DUPFD_CLOEXEC (F_LINUX_SPECIFIC_BASE + 6) + +/* + * Request nofications on a directory. + * See below for events that may be notified. + */ +#define F_NOTIFY (F_LINUX_SPECIFIC_BASE+2) + +/* + * Set and get of pipe page size array + */ +#define F_SETPIPE_SZ (F_LINUX_SPECIFIC_BASE + 7) +#define F_GETPIPE_SZ (F_LINUX_SPECIFIC_BASE + 8) + +/* + * Set/Get seals + */ +#define F_ADD_SEALS (F_LINUX_SPECIFIC_BASE + 9) +#define F_GET_SEALS (F_LINUX_SPECIFIC_BASE + 10) + +/* + * Types of seals + */ +#define F_SEAL_SEAL 0x0001 /* prevent further seals from being set */ +#define F_SEAL_SHRINK 0x0002 /* prevent file from shrinking */ +#define F_SEAL_GROW 0x0004 /* prevent file from growing */ +#define F_SEAL_WRITE 0x0008 /* prevent writes */ +/* (1U << 31) is reserved for signed error codes */ + +/* + * Types of directory notifications that may be requested. + */ +#define DN_ACCESS 0x00000001 /* File accessed */ +#define DN_MODIFY 0x00000002 /* File modified */ +#define DN_CREATE 0x00000004 /* File created */ +#define DN_DELETE 0x00000008 /* File removed */ +#define DN_RENAME 0x00000010 /* File renamed */ +#define DN_ATTRIB 0x00000020 /* File changed attibutes */ +#define DN_MULTISHOT 0x80000000 /* Don't remove notifier */ + +#define AT_FDCWD -100 /* Special value used to indicate + openat should use the current + working directory. */ +#define AT_SYMLINK_NOFOLLOW 0x100 /* Do not follow symbolic links. */ +#define AT_REMOVEDIR 0x200 /* Remove directory instead of + unlinking file. */ +#define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */ +#define AT_NO_AUTOMOUNT 0x800 /* Suppress terminal automount traversal */ +#define AT_EMPTY_PATH 0x1000 /* Allow empty relative pathname */ + +#define AT_STATX_SYNC_TYPE 0x6000 /* Type of synchronisation required from statx() */ +#define AT_STATX_SYNC_AS_STAT 0x0000 /* - Do whatever stat() does */ +#define AT_STATX_FORCE_SYNC 0x2000 /* - Force the attributes to be sync'd with the server */ +#define AT_STATX_DONT_SYNC 0x4000 /* - Don't sync attributes with the server */ + + +#endif /* _UAPI_LINUX_FCNTL_H */ diff --git a/tools/include/uapi/linux/stat.h b/tools/include/uapi/linux/stat.h new file mode 100644 index 000000000000..51a6b86e3700 --- /dev/null +++ b/tools/include/uapi/linux/stat.h @@ -0,0 +1,176 @@ +#ifndef _UAPI_LINUX_STAT_H +#define _UAPI_LINUX_STAT_H + +#include <linux/types.h> + +#if defined(__KERNEL__) || !defined(__GLIBC__) || (__GLIBC__ < 2) + +#define S_IFMT 00170000 +#define S_IFSOCK 0140000 +#define S_IFLNK 0120000 +#define S_IFREG 0100000 +#define S_IFBLK 0060000 +#define S_IFDIR 0040000 +#define S_IFCHR 0020000 +#define S_IFIFO 0010000 +#define S_ISUID 0004000 +#define S_ISGID 0002000 +#define S_ISVTX 0001000 + +#define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK) +#define S_ISREG(m) (((m) & S_IFMT) == S_IFREG) +#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR) +#define S_ISCHR(m) (((m) & S_IFMT) == S_IFCHR) +#define S_ISBLK(m) (((m) & S_IFMT) == S_IFBLK) +#define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO) +#define S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK) + +#define S_IRWXU 00700 +#define S_IRUSR 00400 +#define S_IWUSR 00200 +#define S_IXUSR 00100 + +#define S_IRWXG 00070 +#define S_IRGRP 00040 +#define S_IWGRP 00020 +#define S_IXGRP 00010 + +#define S_IRWXO 00007 +#define S_IROTH 00004 +#define S_IWOTH 00002 +#define S_IXOTH 00001 + +#endif + +/* + * Timestamp structure for the timestamps in struct statx. + * + * tv_sec holds the number of seconds before (negative) or after (positive) + * 00:00:00 1st January 1970 UTC. + * + * tv_nsec holds a number of nanoseconds before (0..-999,999,999 if tv_sec is + * negative) or after (0..999,999,999 if tv_sec is positive) the tv_sec time. + * + * Note that if both tv_sec and tv_nsec are non-zero, then the two values must + * either be both positive or both negative. + * + * __reserved is held in case we need a yet finer resolution. + */ +struct statx_timestamp { + __s64 tv_sec; + __s32 tv_nsec; + __s32 __reserved; +}; + +/* + * Structures for the extended file attribute retrieval system call + * (statx()). + * + * The caller passes a mask of what they're specifically interested in as a + * parameter to statx(). What statx() actually got will be indicated in + * st_mask upon return. + * + * For each bit in the mask argument: + * + * - if the datum is not supported: + * + * - the bit will be cleared, and + * + * - the datum will be set to an appropriate fabricated value if one is + * available (eg. CIFS can take a default uid and gid), otherwise + * + * - the field will be cleared; + * + * - otherwise, if explicitly requested: + * + * - the datum will be synchronised to the server if AT_STATX_FORCE_SYNC is + * set or if the datum is considered out of date, and + * + * - the field will be filled in and the bit will be set; + * + * - otherwise, if not requested, but available in approximate form without any + * effort, it will be filled in anyway, and the bit will be set upon return + * (it might not be up to date, however, and no attempt will be made to + * synchronise the internal state first); + * + * - otherwise the field and the bit will be cleared before returning. + * + * Items in STATX_BASIC_STATS may be marked unavailable on return, but they + * will have values installed for compatibility purposes so that stat() and + * co. can be emulated in userspace. + */ +struct statx { + /* 0x00 */ + __u32 stx_mask; /* What results were written [uncond] */ + __u32 stx_blksize; /* Preferred general I/O size [uncond] */ + __u64 stx_attributes; /* Flags conveying information about the file [uncond] */ + /* 0x10 */ + __u32 stx_nlink; /* Number of hard links */ + __u32 stx_uid; /* User ID of owner */ + __u32 stx_gid; /* Group ID of owner */ + __u16 stx_mode; /* File mode */ + __u16 __spare0[1]; + /* 0x20 */ + __u64 stx_ino; /* Inode number */ + __u64 stx_size; /* File size */ + __u64 stx_blocks; /* Number of 512-byte blocks allocated */ + __u64 __spare1[1]; + /* 0x40 */ + struct statx_timestamp stx_atime; /* Last access time */ + struct statx_timestamp stx_btime; /* File creation time */ + struct statx_timestamp stx_ctime; /* Last attribute change time */ + struct statx_timestamp stx_mtime; /* Last data modification time */ + /* 0x80 */ + __u32 stx_rdev_major; /* Device ID of special file [if bdev/cdev] */ + __u32 stx_rdev_minor; + __u32 stx_dev_major; /* ID of device containing file [uncond] */ + __u32 stx_dev_minor; + /* 0x90 */ + __u64 __spare2[14]; /* Spare space for future expansion */ + /* 0x100 */ +}; + +/* + * Flags to be stx_mask + * + * Query request/result mask for statx() and struct statx::stx_mask. + * + * These bits should be set in the mask argument of statx() to request + * particular items when calling statx(). + */ +#define STATX_TYPE 0x00000001U /* Want/got stx_mode & S_IFMT */ +#define STATX_MODE 0x00000002U /* Want/got stx_mode & ~S_IFMT */ +#define STATX_NLINK 0x00000004U /* Want/got stx_nlink */ +#define STATX_UID 0x00000008U /* Want/got stx_uid */ +#define STATX_GID 0x00000010U /* Want/got stx_gid */ +#define STATX_ATIME 0x00000020U /* Want/got stx_atime */ +#define STATX_MTIME 0x00000040U /* Want/got stx_mtime */ +#define STATX_CTIME 0x00000080U /* Want/got stx_ctime */ +#define STATX_INO 0x00000100U /* Want/got stx_ino */ +#define STATX_SIZE 0x00000200U /* Want/got stx_size */ +#define STATX_BLOCKS 0x00000400U /* Want/got stx_blocks */ +#define STATX_BASIC_STATS 0x000007ffU /* The stuff in the normal stat struct */ +#define STATX_BTIME 0x00000800U /* Want/got stx_btime */ +#define STATX_ALL 0x00000fffU /* All currently supported flags */ + +/* + * Attributes to be found in stx_attributes + * + * These give information about the features or the state of a file that might + * be of use to ordinary userspace programs such as GUIs or ls rather than + * specialised tools. + * + * Note that the flags marked [I] correspond to generic FS_IOC_FLAGS + * semantically. Where possible, the numerical value is picked to correspond + * also. + */ +#define STATX_ATTR_COMPRESSED 0x00000004 /* [I] File is compressed by the fs */ +#define STATX_ATTR_IMMUTABLE 0x00000010 /* [I] File is marked immutable */ +#define STATX_ATTR_APPEND 0x00000020 /* [I] File is append-only */ +#define STATX_ATTR_NODUMP 0x00000040 /* [I] File is not to be dumped */ +#define STATX_ATTR_ENCRYPTED 0x00000800 /* [I] File requires key to decrypt in fs */ + +#define STATX_ATTR_AUTOMOUNT 0x00001000 /* Dir: Automount trigger */ + + +#endif /* _UAPI_LINUX_STAT_H */ diff --git a/tools/perf/MANIFEST b/tools/perf/MANIFEST index 7ea8a3ba097b..776f6b23ea2e 100644 --- a/tools/perf/MANIFEST +++ b/tools/perf/MANIFEST @@ -72,9 +72,11 @@ tools/include/uapi/asm-generic/mman-common.h tools/include/uapi/asm-generic/mman.h tools/include/uapi/linux/bpf.h tools/include/uapi/linux/bpf_common.h +tools/include/uapi/linux/fcntl.h tools/include/uapi/linux/hw_breakpoint.h tools/include/uapi/linux/mman.h tools/include/uapi/linux/perf_event.h +tools/include/uapi/linux/stat.h tools/include/linux/poison.h tools/include/linux/rbtree.h tools/include/linux/rbtree_augmented.h diff --git a/tools/perf/check-headers.sh b/tools/perf/check-headers.sh index c747bfd7f14d..83fe2202382e 100644 --- a/tools/perf/check-headers.sh +++ b/tools/perf/check-headers.sh @@ -1,7 +1,9 @@ #!/bin/sh

HEADERS=' +include/uapi/linux/fcntl.h include/uapi/linux/perf_event.h +include/uapi/linux/stat.h include/linux/hash.h include/uapi/linux/hw_breakpoint.h arch/x86/include/asm/disabled-features.h

From: Arnaldo Carvalho de Melo acme@redhat.com

commit f6441aff8946f7fd6ab730d7eb9eba18a9ebeba4 upstream.

Will be used to adopt the more stringent version of ARRAY_SIZE(), the one in the kernel sources.

Cc: Adrian Hunter adrian.hunter@intel.com Cc: David Ahern dsahern@gmail.com Cc: Jiri Olsa jolsa@kernel.org Cc: Namhyung Kim namhyung@kernel.org Cc: Wang Nan wangnan0@huawei.com Link: http://lkml.kernel.org/n/tip-d85dpvay1hoqscpezlntyd8x@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/include/linux/compiler-gcc.h | 3 +++ tools/include/linux/compiler.h | 5 +++++ 2 files changed, 8 insertions(+)

diff --git a/tools/include/linux/compiler-gcc.h b/tools/include/linux/compiler-gcc.h index 616935f1ff56..825d44f89a29 100644 --- a/tools/include/linux/compiler-gcc.h +++ b/tools/include/linux/compiler-gcc.h @@ -16,3 +16,6 @@ #if GCC_VERSION >= 40300 # define __compiletime_error(message) __attribute__((error(message))) #endif /* GCC_VERSION >= 40300 */ + +/* &a[0] degrades to a pointer: a different type from an array */ +#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index c9e65e8faacd..23299d7e7160 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -17,6 +17,11 @@ # define __always_inline inline __attribute__((always_inline)) #endif

+/* Are two types/vars the same type (ignoring qualifiers)? */ +#ifndef __same_type +# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) +#endif + #ifdef __ANDROID__ /* * FIXME: Big hammer to get rid of tons of:

From: Arnaldo Carvalho de Melo acme@redhat.com

commit 68289cbd83eaa20faef7cc818121bc8e769065de upstream.

As tools/include/linux/kernel.h has it now, with the goodies present in the kernel.h counterpart, i.e. checking that the parameter is an array at build time.

Cc: Adrian Hunter adrian.hunter@intel.com Cc: David Ahern dsahern@gmail.com Cc: Jiri Olsa jolsa@kernel.org Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Namhyung Kim namhyung@kernel.org Cc: Wang Nan wangnan0@huawei.com Link: http://lkml.kernel.org/n/tip-v0b41ivu6z6dyugbq9ffa9ez@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/include/linux/hashtable.h | 4 ---- 1 file changed, 4 deletions(-)

diff --git a/tools/include/linux/hashtable.h b/tools/include/linux/hashtable.h index c65cc0aa2659..251eabf2a05e 100644 --- a/tools/include/linux/hashtable.h +++ b/tools/include/linux/hashtable.h @@ -13,10 +13,6 @@ #include <linux/hash.h> #include <linux/log2.h>

-#ifndef ARRAY_SIZE -#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) -#endif - #define DEFINE_HASHTABLE(name, bits) \ struct hlist_head name[1 << (bits)] = \ { [0 ... ((1 << (bits)) - 1)] = HLIST_HEAD_INIT }

There are pros and cons of dealing with tools in the kernel directory. The pros are the fact that development happens fast, and new features can be added to the kernel and the tools at the same times. The cons are when dealing with backported kernel patches, it can be necessary to backport parts of the tool changes as well.

For 4.9.y so far, we have backported individual patches. That quickly breaks down when there are minor differences between how backports were handled, so grabbing 40+ patch long series can be difficult, not impossible, but really frustrating to attempt.

To help mitigate this mess, here's a single big patch to sync up the objtool logic to the 4.14.47 version of the tool. From this point forward (after some other minor header file patches are applied), the tool should be in sync and much easier to maintain over time.

This has survivied my limited testing, and as the codebase is identical to 4.14.47, I'm pretty comfortable dropping this big change in here in 4.9.y. Hopefully all goes well...

Cc: Josh Poimboeuf jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/include/asm/orc_types.h | 107 ++ arch/x86/include/asm/unwind_hints.h | 103 ++ tools/objtool/Build | 3 + .../Documentation/stack-validation.txt | 195 +-- tools/objtool/Makefile | 35 +- tools/objtool/arch.h | 65 +- tools/objtool/arch/x86/Build | 10 +- tools/objtool/arch/x86/decode.c | 408 ++++- .../arch/x86/{insn => include/asm}/inat.h | 12 +- .../x86/{insn => include/asm}/inat_types.h | 0 .../arch/x86/{insn => include/asm}/insn.h | 2 +- .../objtool/arch/x86/include/asm/orc_types.h | 107 ++ tools/objtool/arch/x86/{insn => lib}/inat.c | 2 +- tools/objtool/arch/x86/{insn => lib}/insn.c | 4 +- .../arch/x86/{insn => lib}/x86-opcode-map.txt | 15 +- .../x86/{insn => tools}/gen-insn-attr-x86.awk | 1 + tools/objtool/builtin-check.c | 9 +- tools/objtool/builtin-orc.c | 68 + tools/objtool/builtin.h | 6 + tools/objtool/cfi.h | 55 + tools/objtool/check.c | 1329 ++++++++++++++--- tools/objtool/check.h | 39 +- tools/objtool/elf.c | 284 +++- tools/objtool/elf.h | 21 +- tools/objtool/objtool.c | 12 +- tools/objtool/orc.h | 30 + tools/objtool/orc_dump.c | 213 +++ tools/objtool/orc_gen.c | 221 +++ tools/objtool/special.c | 6 +- tools/objtool/sync-check.sh | 29 + tools/objtool/warn.h | 10 + 31 files changed, 2887 insertions(+), 514 deletions(-) create mode 100644 arch/x86/include/asm/orc_types.h create mode 100644 arch/x86/include/asm/unwind_hints.h rename tools/objtool/arch/x86/{insn => include/asm}/inat.h (95%) rename tools/objtool/arch/x86/{insn => include/asm}/inat_types.h (100%) rename tools/objtool/arch/x86/{insn => include/asm}/insn.h (99%) create mode 100644 tools/objtool/arch/x86/include/asm/orc_types.h rename tools/objtool/arch/x86/{insn => lib}/inat.c (99%) rename tools/objtool/arch/x86/{insn => lib}/insn.c (99%) rename tools/objtool/arch/x86/{insn => lib}/x86-opcode-map.txt (99%) rename tools/objtool/arch/x86/{insn => tools}/gen-insn-attr-x86.awk (99%) create mode 100644 tools/objtool/builtin-orc.c create mode 100644 tools/objtool/cfi.h create mode 100644 tools/objtool/orc.h create mode 100644 tools/objtool/orc_dump.c create mode 100644 tools/objtool/orc_gen.c create mode 100644 tools/objtool/sync-check.sh

diff --git a/arch/x86/include/asm/orc_types.h b/arch/x86/include/asm/orc_types.h new file mode 100644 index 000000000000..7dc777a6cb40 --- /dev/null +++ b/arch/x86/include/asm/orc_types.h @@ -0,0 +1,107 @@ +/* + * Copyright (C) 2017 Josh Poimboeuf jpoimboe@redhat.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ + +#ifndef _ORC_TYPES_H +#define _ORC_TYPES_H + +#include <linux/types.h> +#include <linux/compiler.h> + +/* + * The ORC_REG_* registers are base registers which are used to find other + * registers on the stack. + * + * ORC_REG_PREV_SP, also known as DWARF Call Frame Address (CFA), is the + * address of the previous frame: the caller's SP before it called the current + * function. + * + * ORC_REG_UNDEFINED means the corresponding register's value didn't change in + * the current frame. + * + * The most commonly used base registers are SP and BP -- which the previous SP + * is usually based on -- and PREV_SP and UNDEFINED -- which the previous BP is + * usually based on. + * + * The rest of the base registers are needed for special cases like entry code + * and GCC realigned stacks. + */ +#define ORC_REG_UNDEFINED 0 +#define ORC_REG_PREV_SP 1 +#define ORC_REG_DX 2 +#define ORC_REG_DI 3 +#define ORC_REG_BP 4 +#define ORC_REG_SP 5 +#define ORC_REG_R10 6 +#define ORC_REG_R13 7 +#define ORC_REG_BP_INDIRECT 8 +#define ORC_REG_SP_INDIRECT 9 +#define ORC_REG_MAX 15 + +/* + * ORC_TYPE_CALL: Indicates that sp_reg+sp_offset resolves to PREV_SP (the + * caller's SP right before it made the call). Used for all callable + * functions, i.e. all C code and all callable asm functions. + * + * ORC_TYPE_REGS: Used in entry code to indicate that sp_reg+sp_offset points + * to a fully populated pt_regs from a syscall, interrupt, or exception. + * + * ORC_TYPE_REGS_IRET: Used in entry code to indicate that sp_reg+sp_offset + * points to the iret return frame. + * + * The UNWIND_HINT macros are used only for the unwind_hint struct. They + * aren't used in struct orc_entry due to size and complexity constraints. + * Objtool converts them to real types when it converts the hints to orc + * entries. + */ +#define ORC_TYPE_CALL 0 +#define ORC_TYPE_REGS 1 +#define ORC_TYPE_REGS_IRET 2 +#define UNWIND_HINT_TYPE_SAVE 3 +#define UNWIND_HINT_TYPE_RESTORE 4 + +#ifndef __ASSEMBLY__ +/* + * This struct is more or less a vastly simplified version of the DWARF Call + * Frame Information standard. It contains only the necessary parts of DWARF + * CFI, simplified for ease of access by the in-kernel unwinder. It tells the + * unwinder how to find the previous SP and BP (and sometimes entry regs) on + * the stack for a given code address. Each instance of the struct corresponds + * to one or more code locations. + */ +struct orc_entry { + s16 sp_offset; + s16 bp_offset; + unsigned sp_reg:4; + unsigned bp_reg:4; + unsigned type:2; +}; + +/* + * This struct is used by asm and inline asm code to manually annotate the + * location of registers on the stack for the ORC unwinder. + * + * Type can be either ORC_TYPE_* or UNWIND_HINT_TYPE_*. + */ +struct unwind_hint { + u32 ip; + s16 sp_offset; + u8 sp_reg; + u8 type; +}; +#endif /* __ASSEMBLY__ */ + +#endif /* _ORC_TYPES_H */ diff --git a/arch/x86/include/asm/unwind_hints.h b/arch/x86/include/asm/unwind_hints.h new file mode 100644 index 000000000000..5e02b11c9b86 --- /dev/null +++ b/arch/x86/include/asm/unwind_hints.h @@ -0,0 +1,103 @@ +#ifndef _ASM_X86_UNWIND_HINTS_H +#define _ASM_X86_UNWIND_HINTS_H + +#include "orc_types.h" + +#ifdef __ASSEMBLY__ + +/* + * In asm, there are two kinds of code: normal C-type callable functions and + * the rest. The normal callable functions can be called by other code, and + * don't do anything unusual with the stack. Such normal callable functions + * are annotated with the ENTRY/ENDPROC macros. Most asm code falls in this + * category. In this case, no special debugging annotations are needed because + * objtool can automatically generate the ORC data for the ORC unwinder to read + * at runtime. + * + * Anything which doesn't fall into the above category, such as syscall and + * interrupt handlers, tends to not be called directly by other functions, and + * often does unusual non-C-function-type things with the stack pointer. Such + * code needs to be annotated such that objtool can understand it. The + * following CFI hint macros are for this type of code. + * + * These macros provide hints to objtool about the state of the stack at each + * instruction. Objtool starts from the hints and follows the code flow, + * making automatic CFI adjustments when it sees pushes and pops, filling out + * the debuginfo as necessary. It will also warn if it sees any + * inconsistencies. + */ +.macro UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=0 type=ORC_TYPE_CALL +#ifdef CONFIG_STACK_VALIDATION +.Lunwind_hint_ip_@: + .pushsection .discard.unwind_hints + /* struct unwind_hint */ + .long .Lunwind_hint_ip_@ - . + .short \sp_offset + .byte \sp_reg + .byte \type + .popsection +#endif +.endm + +.macro UNWIND_HINT_EMPTY + UNWIND_HINT sp_reg=ORC_REG_UNDEFINED +.endm + +.macro UNWIND_HINT_REGS base=%rsp offset=0 indirect=0 extra=1 iret=0 + .if \base == %rsp && \indirect + .set sp_reg, ORC_REG_SP_INDIRECT + .elseif \base == %rsp + .set sp_reg, ORC_REG_SP + .elseif \base == %rbp + .set sp_reg, ORC_REG_BP + .elseif \base == %rdi + .set sp_reg, ORC_REG_DI + .elseif \base == %rdx + .set sp_reg, ORC_REG_DX + .elseif \base == %r10 + .set sp_reg, ORC_REG_R10 + .else + .error "UNWIND_HINT_REGS: bad base register" + .endif + + .set sp_offset, \offset + + .if \iret + .set type, ORC_TYPE_REGS_IRET + .elseif \extra == 0 + .set type, ORC_TYPE_REGS_IRET + .set sp_offset, \offset + (16*8) + .else + .set type, ORC_TYPE_REGS + .endif + + UNWIND_HINT sp_reg=sp_reg sp_offset=sp_offset type=type +.endm + +.macro UNWIND_HINT_IRET_REGS base=%rsp offset=0 + UNWIND_HINT_REGS base=\base offset=\offset iret=1 +.endm + +.macro UNWIND_HINT_FUNC sp_offset=8 + UNWIND_HINT sp_offset=\sp_offset +.endm + +#else /* !__ASSEMBLY__ */ + +#define UNWIND_HINT(sp_reg, sp_offset, type) \ + "987: \n\t" \ + ".pushsection .discard.unwind_hints\n\t" \ + /* struct unwind_hint */ \ + ".long 987b - .\n\t" \ + ".short " __stringify(sp_offset) "\n\t" \ + ".byte " __stringify(sp_reg) "\n\t" \ + ".byte " __stringify(type) "\n\t" \ + ".popsection\n\t" + +#define UNWIND_HINT_SAVE UNWIND_HINT(0, 0, UNWIND_HINT_TYPE_SAVE) + +#define UNWIND_HINT_RESTORE UNWIND_HINT(0, 0, UNWIND_HINT_TYPE_RESTORE) + +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_X86_UNWIND_HINTS_H */ diff --git a/tools/objtool/Build b/tools/objtool/Build index 6f2e1987c4d9..749becdf5b90 100644 --- a/tools/objtool/Build +++ b/tools/objtool/Build @@ -1,6 +1,9 @@ objtool-y += arch/$(SRCARCH)/ objtool-y += builtin-check.o +objtool-y += builtin-orc.o objtool-y += check.o +objtool-y += orc_gen.o +objtool-y += orc_dump.o objtool-y += elf.o objtool-y += special.o objtool-y += objtool.o diff --git a/tools/objtool/Documentation/stack-validation.txt b/tools/objtool/Documentation/stack-validation.txt index 55a60d331f47..3995735a878f 100644 --- a/tools/objtool/Documentation/stack-validation.txt +++ b/tools/objtool/Documentation/stack-validation.txt @@ -11,9 +11,6 @@ analyzes every .o file and ensures the validity of its stack metadata. It enforces a set of rules on asm code and C inline assembly code so that stack traces can be reliable.

-Currently it only checks frame pointer usage, but there are plans to add -CFI validation for C files and CFI generation for asm files. - For each function, it recursively follows all possible code paths and validates the correct frame pointer state at each instruction.

@@ -23,6 +20,10 @@ alternative execution paths to a given instruction (or set of instructions). Similarly, it knows how to follow switch statements, for which gcc sometimes uses jump tables.

+(Objtool also has an 'orc generate' subcommand which generates debuginfo +for the ORC unwinder. See Documentation/x86/orc-unwinder.txt in the +kernel tree for more details.) +

Why do we need stack metadata validation? ----------------------------------------- @@ -93,62 +94,24 @@ a) More reliable stack traces for frame pointer enabled kernels or at the very end of the function after the stack frame has been destroyed. This is an inherent limitation of frame pointers.

-b) 100% reliable stack traces for DWARF enabled kernels - - (NOTE: This is not yet implemented) - - As an alternative to frame pointers, DWARF Call Frame Information - (CFI) metadata can be used to walk the stack. Unlike frame pointers, - CFI metadata is out of band. So it doesn't affect runtime - performance and it can be reliable even when interrupts or exceptions - are involved. - - For C code, gcc automatically generates DWARF CFI metadata. But for - asm code, generating CFI is a tedious manual approach which requires - manually placed .cfi assembler macros to be scattered throughout the - code. It's clumsy and very easy to get wrong, and it makes the real - code harder to read. - - Stacktool will improve this situation in several ways. For code - which already has CFI annotations, it will validate them. For code - which doesn't have CFI annotations, it will generate them. So an - architecture can opt to strip out all the manual .cfi annotations - from their asm code and have objtool generate them instead. +b) ORC (Oops Rewind Capability) unwind table generation

- We might also add a runtime stack validation debug option where we - periodically walk the stack from schedule() and/or an NMI to ensure - that the stack metadata is sane and that we reach the bottom of the - stack. + An alternative to frame pointers and DWARF, ORC unwind data can be + used to walk the stack. Unlike frame pointers, ORC data is out of + band. So it doesn't affect runtime performance and it can be + reliable even when interrupts or exceptions are involved.

- So the benefit of objtool here will be that external tooling should - always show perfect stack traces. And the same will be true for - kernel warning/oops traces if the architecture has a runtime DWARF - unwinder. + For more details, see Documentation/x86/orc-unwinder.txt.

c) Higher live patching compatibility rate

- (NOTE: This is not yet implemented) - - Currently with CONFIG_LIVEPATCH there's a basic live patching - framework which is safe for roughly 85-90% of "security" fixes. But - patches can't have complex features like function dependency or - prototype changes, or data structure changes. - - There's a strong need to support patches which have the more complex - features so that the patch compatibility rate for security fixes can - eventually approach something resembling 100%. To achieve that, a - "consistency model" is needed, which allows tasks to be safely - transitioned from an unpatched state to a patched state. - - One of the key requirements of the currently proposed livepatch - consistency model [*] is that it needs to walk the stack of each - sleeping task to determine if it can be transitioned to the patched - state. If objtool can ensure that stack traces are reliable, this - consistency model can be used and the live patching compatibility - rate can be improved significantly. - - [*] https://lkml.kernel.org/r/cover.1423499826.git.jpoimboe@redhat.com + Livepatch has an optional "consistency model", which is needed for + more complex patches. In order for the consistency model to work, + stack traces need to be reliable (or an unreliable condition needs to + be detectable). Objtool makes that possible.

+ For more details, see the livepatch documentation in the Linux kernel + source tree at Documentation/livepatch/livepatch.txt.

Rules ----- @@ -201,80 +164,84 @@ To achieve the validation, objtool enforces the following rules: return normally.

-Errors in .S files ------------------- +Objtool warnings +---------------- + +For asm files, if you're getting an error which doesn't make sense, +first make sure that the affected code follows the above rules.

-If you're getting an error in a compiled .S file which you don't -understand, first make sure that the affected code follows the above -rules. +For C files, the common culprits are inline asm statements and calls to +"noreturn" functions. See below for more details. + +Another possible cause for errors in C code is if the Makefile removes +-fno-omit-frame-pointer or adds -fomit-frame-pointer to the gcc options.

Here are some examples of common warnings reported by objtool, what they mean, and suggestions for how to fix them.

-1. asm_file.o: warning: objtool: func()+0x128: call without frame pointer save/setup +1. file.o: warning: objtool: func()+0x128: call without frame pointer save/setup

The func() function made a function call without first saving and/or - updating the frame pointer. - - If func() is indeed a callable function, add proper frame pointer - logic using the FRAME_BEGIN and FRAME_END macros. Otherwise, remove - its ELF function annotation by changing ENDPROC to END. - - If you're getting this error in a .c file, see the "Errors in .c - files" section. + updating the frame pointer, and CONFIG_FRAME_POINTER is enabled.

+ If the error is for an asm file, and func() is indeed a callable + function, add proper frame pointer logic using the FRAME_BEGIN and + FRAME_END macros. Otherwise, if it's not a callable function, remove + its ELF function annotation by changing ENDPROC to END, and instead + use the manual unwind hint macros in asm/unwind_hints.h.

-2. asm_file.o: warning: objtool: .text+0x53: return instruction outside of a callable function + If it's a GCC-compiled .c file, the error may be because the function + uses an inline asm() statement which has a "call" instruction. An + asm() statement with a call instruction must declare the use of the + stack pointer in its output operand. On x86_64, this means adding + the ASM_CALL_CONSTRAINT as an output constraint:

- A return instruction was detected, but objtool couldn't find a way - for a callable function to reach the instruction. + asm volatile("call func" : ASM_CALL_CONSTRAINT);

- If the return instruction is inside (or reachable from) a callable - function, the function needs to be annotated with the ENTRY/ENDPROC - macros. + Otherwise the stack frame may not get created before the call.

- If you _really_ need a return instruction outside of a function, and - are 100% sure that it won't affect stack traces, you can tell - objtool to ignore it. See the "Adding exceptions" section below.

+2. file.o: warning: objtool: .text+0x53: unreachable instruction

-3. asm_file.o: warning: objtool: func()+0x9: function has unreachable instruction + Objtool couldn't find a code path to reach the instruction.

- The instruction lives inside of a callable function, but there's no - possible control flow path from the beginning of the function to the - instruction. + If the error is for an asm file, and the instruction is inside (or + reachable from) a callable function, the function should be annotated + with the ENTRY/ENDPROC macros (ENDPROC is the important one). + Otherwise, the code should probably be annotated with the unwind hint + macros in asm/unwind_hints.h so objtool and the unwinder can know the + stack state associated with the code.

- If the instruction is actually needed, and it's actually in a - callable function, ensure that its function is properly annotated - with ENTRY/ENDPROC. + If you're 100% sure the code won't affect stack traces, or if you're + a just a bad person, you can tell objtool to ignore it. See the + "Adding exceptions" section below.

If it's not actually in a callable function (e.g. kernel entry code), change ENDPROC to END.

-4. asm_file.o: warning: objtool: func(): can't find starting instruction +4. file.o: warning: objtool: func(): can't find starting instruction or - asm_file.o: warning: objtool: func()+0x11dd: can't decode instruction + file.o: warning: objtool: func()+0x11dd: can't decode instruction

- Did you put data in a text section? If so, that can confuse + Does the file have data in a text section? If so, that can confuse objtool's instruction decoder. Move the data to a more appropriate section like .data or .rodata.

-5. asm_file.o: warning: objtool: func()+0x6: kernel entry/exit from callable instruction - - This is a kernel entry/exit instruction like sysenter or sysret. - Such instructions aren't allowed in a callable function, and are most - likely part of the kernel entry code. +5. file.o: warning: objtool: func()+0x6: unsupported instruction in callable function

- If the instruction isn't actually in a callable function, change - ENDPROC to END. + This is a kernel entry/exit instruction like sysenter or iret. Such + instructions aren't allowed in a callable function, and are most + likely part of the kernel entry code. They should usually not have + the callable function annotation (ENDPROC) and should always be + annotated with the unwind hint macros in asm/unwind_hints.h.

-6. asm_file.o: warning: objtool: func()+0x26: sibling call from callable instruction with changed frame pointer +6. file.o: warning: objtool: func()+0x26: sibling call from callable instruction with modified stack frame

- This is a dynamic jump or a jump to an undefined symbol. Stacktool + This is a dynamic jump or a jump to an undefined symbol. Objtool assumed it's a sibling call and detected that the frame pointer wasn't first restored to its original state.

@@ -282,24 +249,28 @@ they mean, and suggestions for how to fix them. destination code to the local file.

If the instruction is not actually in a callable function (e.g. - kernel entry code), change ENDPROC to END. + kernel entry code), change ENDPROC to END and annotate manually with + the unwind hint macros in asm/unwind_hints.h.

-7. asm_file: warning: objtool: func()+0x5c: frame pointer state mismatch +7. file: warning: objtool: func()+0x5c: stack state mismatch

The instruction's frame pointer state is inconsistent, depending on which execution path was taken to reach the instruction.

- Make sure the function pushes and sets up the frame pointer (for - x86_64, this means rbp) at the beginning of the function and pops it - at the end of the function. Also make sure that no other code in the - function touches the frame pointer. + Make sure that, when CONFIG_FRAME_POINTER is enabled, the function + pushes and sets up the frame pointer (for x86_64, this means rbp) at + the beginning of the function and pops it at the end of the function. + Also make sure that no other code in the function touches the frame + pointer.

+ Another possibility is that the code has some asm or inline asm which + does some unusual things to the stack or the frame pointer. In such + cases it's probably appropriate to use the unwind hint macros in + asm/unwind_hints.h.

-Errors in .c files -------------------

-1. c_file.o: warning: objtool: funcA() falls through to next function funcB() +8. file.o: warning: objtool: funcA() falls through to next function funcB()

This means that funcA() doesn't end with a return instruction or an unconditional jump, and that objtool has determined that the function @@ -318,22 +289,6 @@ Errors in .c files might be corrupt due to a gcc bug. For more details, see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70646

-2. If you're getting any other objtool error in a compiled .c file, it - may be because the file uses an asm() statement which has a "call" - instruction. An asm() statement with a call instruction must declare - the use of the stack pointer in its output operand. For example, on - x86_64: - - register void *__sp asm("rsp"); - asm volatile("call func" : "+r" (__sp)); - - Otherwise the stack frame may not get created before the call. - -3. Another possible cause for errors in C code is if the Makefile removes - -fno-omit-frame-pointer or adds -fomit-frame-pointer to the gcc options. - -Also see the above section for .S file errors for more information what -the individual error messages mean.

If the error doesn't seem to make sense, it could be a bug in objtool. Feel free to ask the objtool maintainer for help. diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile index 041b493ad3ab..e6acc281dd37 100644 --- a/tools/objtool/Makefile +++ b/tools/objtool/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 include ../scripts/Makefile.include include ../scripts/Makefile.arch

@@ -6,17 +7,19 @@ ARCH := x86 endif

# always use the host compiler -CC = gcc -LD = ld -AR = ar +HOSTCC ?= gcc +HOSTLD ?= ld +CC = $(HOSTCC) +LD = $(HOSTLD) +AR = ar

ifeq ($(srctree),) -srctree := $(patsubst %/,%,$(dir $(shell pwd))) +srctree := $(patsubst %/,%,$(dir $(CURDIR))) srctree := $(patsubst %/,%,$(dir $(srctree))) endif

SUBCMD_SRCDIR = $(srctree)/tools/lib/subcmd/ -LIBSUBCMD_OUTPUT = $(if $(OUTPUT),$(OUTPUT),$(PWD)/) +LIBSUBCMD_OUTPUT = $(if $(OUTPUT),$(OUTPUT),$(CURDIR)/) LIBSUBCMD = $(LIBSUBCMD_OUTPUT)libsubcmd.a

OBJTOOL := $(OUTPUT)objtool @@ -24,8 +27,11 @@ OBJTOOL_IN := $(OBJTOOL)-in.o

all: $(OBJTOOL)

-INCLUDES := -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi -CFLAGS += -Wall -Werror $(EXTRA_WARNINGS) -fomit-frame-pointer -O2 -g $(INCLUDES) +INCLUDES := -I$(srctree)/tools/include \ + -I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \ + -I$(srctree)/tools/objtool/arch/$(ARCH)/include +WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed +CFLAGS += -Wall -Werror $(WARNINGS) -fomit-frame-pointer -O2 -g $(INCLUDES) LDFLAGS += -lelf $(LIBSUBCMD)

# Allow old libelf to be used: @@ -39,19 +45,8 @@ include $(srctree)/tools/build/Makefile.include $(OBJTOOL_IN): fixdep FORCE @$(MAKE) $(build)=objtool

-# Busybox's diff doesn't have -I, avoid warning in that case -# $(OBJTOOL): $(LIBSUBCMD) $(OBJTOOL_IN) - @(diff -I 2>&1 | grep -q 'option requires an argument' && \ - test -d ../../kernel -a -d ../../tools -a -d ../objtool && (( \ - diff -I'^#include' arch/x86/insn/insn.c ../../arch/x86/lib/insn.c >/dev/null && \ - diff -I'^#include' arch/x86/insn/inat.c ../../arch/x86/lib/inat.c >/dev/null && \ - diff arch/x86/insn/x86-opcode-map.txt ../../arch/x86/lib/x86-opcode-map.txt >/dev/null && \ - diff arch/x86/insn/gen-insn-attr-x86.awk ../../arch/x86/tools/gen-insn-attr-x86.awk >/dev/null && \ - diff -I'^#include' arch/x86/insn/insn.h ../../arch/x86/include/asm/insn.h >/dev/null && \ - diff -I'^#include' arch/x86/insn/inat.h ../../arch/x86/include/asm/inat.h >/dev/null && \ - diff -I'^#include' arch/x86/insn/inat_types.h ../../arch/x86/include/asm/inat_types.h >/dev/null) \ - || echo "warning: objtool: x86 instruction decoder differs from kernel" >&2 )) || true + @$(CONFIG_SHELL) ./sync-check.sh $(QUIET_LINK)$(CC) $(OBJTOOL_IN) $(LDFLAGS) -o $@

@@ -61,7 +56,7 @@ $(LIBSUBCMD): fixdep FORCE clean: $(call QUIET_CLEAN, objtool) $(RM) $(OBJTOOL) $(Q)find $(OUTPUT) -name '*.o' -delete -o -name '.*.cmd' -delete -o -name '.*.d' -delete - $(Q)$(RM) $(OUTPUT)arch/x86/insn/inat-tables.c $(OUTPUT)fixdep + $(Q)$(RM) $(OUTPUT)arch/x86/lib/inat-tables.c $(OUTPUT)fixdep

FORCE:

diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h index a59e061c0b4a..b0d7dc3d71b5 100644 --- a/tools/objtool/arch.h +++ b/tools/objtool/arch.h @@ -19,25 +19,64 @@ #define _ARCH_H

#include <stdbool.h> +#include <linux/list.h> #include "elf.h" +#include "cfi.h"

-#define INSN_FP_SAVE 1 -#define INSN_FP_SETUP 2 -#define INSN_FP_RESTORE 3 -#define INSN_JUMP_CONDITIONAL 4 -#define INSN_JUMP_UNCONDITIONAL 5 -#define INSN_JUMP_DYNAMIC 6 -#define INSN_CALL 7 -#define INSN_CALL_DYNAMIC 8 -#define INSN_RETURN 9 -#define INSN_CONTEXT_SWITCH 10 -#define INSN_NOP 11 -#define INSN_OTHER 12 +#define INSN_JUMP_CONDITIONAL 1 +#define INSN_JUMP_UNCONDITIONAL 2 +#define INSN_JUMP_DYNAMIC 3 +#define INSN_CALL 4 +#define INSN_CALL_DYNAMIC 5 +#define INSN_RETURN 6 +#define INSN_CONTEXT_SWITCH 7 +#define INSN_STACK 8 +#define INSN_BUG 9 +#define INSN_NOP 10 +#define INSN_OTHER 11 #define INSN_LAST INSN_OTHER

+enum op_dest_type { + OP_DEST_REG, + OP_DEST_REG_INDIRECT, + OP_DEST_MEM, + OP_DEST_PUSH, + OP_DEST_LEAVE, +}; + +struct op_dest { + enum op_dest_type type; + unsigned char reg; + int offset; +}; + +enum op_src_type { + OP_SRC_REG, + OP_SRC_REG_INDIRECT, + OP_SRC_CONST, + OP_SRC_POP, + OP_SRC_ADD, + OP_SRC_AND, +}; + +struct op_src { + enum op_src_type type; + unsigned char reg; + int offset; +}; + +struct stack_op { + struct op_dest dest; + struct op_src src; +}; + +void arch_initial_func_cfi_state(struct cfi_state *state); + int arch_decode_instruction(struct elf *elf, struct section *sec, unsigned long offset, unsigned int maxlen, unsigned int *len, unsigned char *type, - unsigned long *displacement); + unsigned long *immediate, struct stack_op *op); + +bool arch_callee_saved_reg(unsigned char reg);

#endif /* _ARCH_H */ diff --git a/tools/objtool/arch/x86/Build b/tools/objtool/arch/x86/Build index debbdb0b5c43..b998412c017d 100644 --- a/tools/objtool/arch/x86/Build +++ b/tools/objtool/arch/x86/Build @@ -1,12 +1,12 @@ objtool-y += decode.o

-inat_tables_script = arch/x86/insn/gen-insn-attr-x86.awk -inat_tables_maps = arch/x86/insn/x86-opcode-map.txt +inat_tables_script = arch/x86/tools/gen-insn-attr-x86.awk +inat_tables_maps = arch/x86/lib/x86-opcode-map.txt

-$(OUTPUT)arch/x86/insn/inat-tables.c: $(inat_tables_script) $(inat_tables_maps) +$(OUTPUT)arch/x86/lib/inat-tables.c: $(inat_tables_script) $(inat_tables_maps) $(call rule_mkdir) $(Q)$(call echo-cmd,gen)$(AWK) -f $(inat_tables_script) $(inat_tables_maps) > $@

-$(OUTPUT)arch/x86/decode.o: $(OUTPUT)arch/x86/insn/inat-tables.c +$(OUTPUT)arch/x86/decode.o: $(OUTPUT)arch/x86/lib/inat-tables.c

-CFLAGS_decode.o += -I$(OUTPUT)arch/x86/insn +CFLAGS_decode.o += -I$(OUTPUT)arch/x86/lib diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 6ac99e3266eb..540a209b78ab 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -19,14 +19,25 @@ #include <stdlib.h>

#define unlikely(cond) (cond) -#include "insn/insn.h" -#include "insn/inat.c" -#include "insn/insn.c" +#include <asm/insn.h> +#include "lib/inat.c" +#include "lib/insn.c"

#include "../../elf.h" #include "../../arch.h" #include "../../warn.h"

+static unsigned char op_to_cfi_reg[][2] = { + {CFI_AX, CFI_R8}, + {CFI_CX, CFI_R9}, + {CFI_DX, CFI_R10}, + {CFI_BX, CFI_R11}, + {CFI_SP, CFI_R12}, + {CFI_BP, CFI_R13}, + {CFI_SI, CFI_R14}, + {CFI_DI, CFI_R15}, +}; + static int is_x86_64(struct elf *elf) { switch (elf->ehdr.e_machine) { @@ -40,24 +51,50 @@ static int is_x86_64(struct elf *elf) } }

+bool arch_callee_saved_reg(unsigned char reg) +{ + switch (reg) { + case CFI_BP: + case CFI_BX: + case CFI_R12: + case CFI_R13: + case CFI_R14: + case CFI_R15: + return true; + + case CFI_AX: + case CFI_CX: + case CFI_DX: + case CFI_SI: + case CFI_DI: + case CFI_SP: + case CFI_R8: + case CFI_R9: + case CFI_R10: + case CFI_R11: + case CFI_RA: + default: + return false; + } +} + int arch_decode_instruction(struct elf *elf, struct section *sec, unsigned long offset, unsigned int maxlen, unsigned int *len, unsigned char *type, - unsigned long *immediate) + unsigned long *immediate, struct stack_op *op) { struct insn insn; - int x86_64; - unsigned char op1, op2, ext; + int x86_64, sign; + unsigned char op1, op2, rex = 0, rex_b = 0, rex_r = 0, rex_w = 0, + rex_x = 0, modrm = 0, modrm_mod = 0, modrm_rm = 0, + modrm_reg = 0, sib = 0;

x86_64 = is_x86_64(elf); if (x86_64 == -1) return -1;

- insn_init(&insn, (void *)(sec->data + offset), maxlen, x86_64); + insn_init(&insn, sec->data->d_buf + offset, maxlen, x86_64); insn_get_length(&insn); - insn_get_opcode(&insn); - insn_get_modrm(&insn); - insn_get_immediate(&insn);

if (!insn_complete(&insn)) { WARN_FUNC("can't decode instruction", sec, offset); @@ -73,67 +110,317 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, op1 = insn.opcode.bytes[0]; op2 = insn.opcode.bytes[1];

+ if (insn.rex_prefix.nbytes) { + rex = insn.rex_prefix.bytes[0]; + rex_w = X86_REX_W(rex) >> 3; + rex_r = X86_REX_R(rex) >> 2; + rex_x = X86_REX_X(rex) >> 1; + rex_b = X86_REX_B(rex); + } + + if (insn.modrm.nbytes) { + modrm = insn.modrm.bytes[0]; + modrm_mod = X86_MODRM_MOD(modrm); + modrm_reg = X86_MODRM_REG(modrm); + modrm_rm = X86_MODRM_RM(modrm); + } + + if (insn.sib.nbytes) + sib = insn.sib.bytes[0]; + switch (op1) { - case 0x55: - if (!insn.rex_prefix.nbytes) - /* push rbp */ - *type = INSN_FP_SAVE; + + case 0x1: + case 0x29: + if (rex_w && !rex_b && modrm_mod == 3 && modrm_rm == 4) { + + /* add/sub reg, %rsp */ + *type = INSN_STACK; + op->src.type = OP_SRC_ADD; + op->src.reg = op_to_cfi_reg[modrm_reg][rex_r]; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + } + break; + + case 0x50 ... 0x57: + + /* push reg */ + *type = INSN_STACK; + op->src.type = OP_SRC_REG; + op->src.reg = op_to_cfi_reg[op1 & 0x7][rex_b]; + op->dest.type = OP_DEST_PUSH; + + break; + + case 0x58 ... 0x5f: + + /* pop reg */ + *type = INSN_STACK; + op->src.type = OP_SRC_POP; + op->dest.type = OP_DEST_REG; + op->dest.reg = op_to_cfi_reg[op1 & 0x7][rex_b]; + break;

- case 0x5d: - if (!insn.rex_prefix.nbytes) - /* pop rbp */ - *type = INSN_FP_RESTORE; + case 0x68: + case 0x6a: + /* push immediate */ + *type = INSN_STACK; + op->src.type = OP_SRC_CONST; + op->dest.type = OP_DEST_PUSH; break;

case 0x70 ... 0x7f: *type = INSN_JUMP_CONDITIONAL; break;

+ case 0x81: + case 0x83: + if (rex != 0x48) + break; + + if (modrm == 0xe4) { + /* and imm, %rsp */ + *type = INSN_STACK; + op->src.type = OP_SRC_AND; + op->src.reg = CFI_SP; + op->src.offset = insn.immediate.value; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + break; + } + + if (modrm == 0xc4) + sign = 1; + else if (modrm == 0xec) + sign = -1; + else + break; + + /* add/sub imm, %rsp */ + *type = INSN_STACK; + op->src.type = OP_SRC_ADD; + op->src.reg = CFI_SP; + op->src.offset = insn.immediate.value * sign; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + break; + case 0x89: - if (insn.rex_prefix.nbytes == 1 && - insn.rex_prefix.bytes[0] == 0x48 && - insn.modrm.nbytes && insn.modrm.bytes[0] == 0xe5) - /* mov rsp, rbp */ - *type = INSN_FP_SETUP; + if (rex_w && !rex_r && modrm_mod == 3 && modrm_reg == 4) { + + /* mov %rsp, reg */ + *type = INSN_STACK; + op->src.type = OP_SRC_REG; + op->src.reg = CFI_SP; + op->dest.type = OP_DEST_REG; + op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b]; + break; + } + + if (rex_w && !rex_b && modrm_mod == 3 && modrm_rm == 4) { + + /* mov reg, %rsp */ + *type = INSN_STACK; + op->src.type = OP_SRC_REG; + op->src.reg = op_to_cfi_reg[modrm_reg][rex_r]; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + break; + } + + /* fallthrough */ + case 0x88: + if (!rex_b && + (modrm_mod == 1 || modrm_mod == 2) && modrm_rm == 5) { + + /* mov reg, disp(%rbp) */ + *type = INSN_STACK; + op->src.type = OP_SRC_REG; + op->src.reg = op_to_cfi_reg[modrm_reg][rex_r]; + op->dest.type = OP_DEST_REG_INDIRECT; + op->dest.reg = CFI_BP; + op->dest.offset = insn.displacement.value; + + } else if (rex_w && !rex_b && modrm_rm == 4 && sib == 0x24) { + + /* mov reg, disp(%rsp) */ + *type = INSN_STACK; + op->src.type = OP_SRC_REG; + op->src.reg = op_to_cfi_reg[modrm_reg][rex_r]; + op->dest.type = OP_DEST_REG_INDIRECT; + op->dest.reg = CFI_SP; + op->dest.offset = insn.displacement.value; + } + + break; + + case 0x8b: + if (rex_w && !rex_b && modrm_mod == 1 && modrm_rm == 5) { + + /* mov disp(%rbp), reg */ + *type = INSN_STACK; + op->src.type = OP_SRC_REG_INDIRECT; + op->src.reg = CFI_BP; + op->src.offset = insn.displacement.value; + op->dest.type = OP_DEST_REG; + op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r]; + + } else if (rex_w && !rex_b && sib == 0x24 && + modrm_mod != 3 && modrm_rm == 4) { + + /* mov disp(%rsp), reg */ + *type = INSN_STACK; + op->src.type = OP_SRC_REG_INDIRECT; + op->src.reg = CFI_SP; + op->src.offset = insn.displacement.value; + op->dest.type = OP_DEST_REG; + op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r]; + } + break;

case 0x8d: - if (insn.rex_prefix.nbytes && - insn.rex_prefix.bytes[0] == 0x48 && - insn.modrm.nbytes && insn.modrm.bytes[0] == 0x2c && - insn.sib.nbytes && insn.sib.bytes[0] == 0x24) - /* lea %(rsp), %rbp */ - *type = INSN_FP_SETUP; + if (sib == 0x24 && rex_w && !rex_b && !rex_x) { + + *type = INSN_STACK; + if (!insn.displacement.value) { + /* lea (%rsp), reg */ + op->src.type = OP_SRC_REG; + } else { + /* lea disp(%rsp), reg */ + op->src.type = OP_SRC_ADD; + op->src.offset = insn.displacement.value; + } + op->src.reg = CFI_SP; + op->dest.type = OP_DEST_REG; + op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r]; + + } else if (rex == 0x48 && modrm == 0x65) { + + /* lea disp(%rbp), %rsp */ + *type = INSN_STACK; + op->src.type = OP_SRC_ADD; + op->src.reg = CFI_BP; + op->src.offset = insn.displacement.value; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + + } else if (rex == 0x49 && modrm == 0x62 && + insn.displacement.value == -8) { + + /* + * lea -0x8(%r10), %rsp + * + * Restoring rsp back to its original value after a + * stack realignment. + */ + *type = INSN_STACK; + op->src.type = OP_SRC_ADD; + op->src.reg = CFI_R10; + op->src.offset = -8; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + + } else if (rex == 0x49 && modrm == 0x65 && + insn.displacement.value == -16) { + + /* + * lea -0x10(%r13), %rsp + * + * Restoring rsp back to its original value after a + * stack realignment. + */ + *type = INSN_STACK; + op->src.type = OP_SRC_ADD; + op->src.reg = CFI_R13; + op->src.offset = -16; + op->dest.type = OP_DEST_REG; + op->dest.reg = CFI_SP; + } + + break; + + case 0x8f: + /* pop to mem */ + *type = INSN_STACK; + op->src.type = OP_SRC_POP; + op->dest.type = OP_DEST_MEM; break;

case 0x90: *type = INSN_NOP; break;

+ case 0x9c: + /* pushf */ + *type = INSN_STACK; + op->src.type = OP_SRC_CONST; + op->dest.type = OP_DEST_PUSH; + break; + + case 0x9d: + /* popf */ + *type = INSN_STACK; + op->src.type = OP_SRC_POP; + op->dest.type = OP_DEST_MEM; + break; + case 0x0f: - if (op2 >= 0x80 && op2 <= 0x8f) + + if (op2 >= 0x80 && op2 <= 0x8f) { + *type = INSN_JUMP_CONDITIONAL; - else if (op2 == 0x05 || op2 == 0x07 || op2 == 0x34 || - op2 == 0x35) + + } else if (op2 == 0x05 || op2 == 0x07 || op2 == 0x34 || + op2 == 0x35) { + /* sysenter, sysret */ *type = INSN_CONTEXT_SWITCH; - else if (op2 == 0x0d || op2 == 0x1f) + + } else if (op2 == 0x0b || op2 == 0xb9) { + + /* ud2 */ + *type = INSN_BUG; + + } else if (op2 == 0x0d || op2 == 0x1f) { + /* nopl/nopw */ *type = INSN_NOP; - else if (op2 == 0x01 && insn.modrm.nbytes && - (insn.modrm.bytes[0] == 0xc2 || - insn.modrm.bytes[0] == 0xd8)) - /* vmlaunch, vmrun */ - *type = INSN_CONTEXT_SWITCH; + + } else if (op2 == 0xa0 || op2 == 0xa8) { + + /* push fs/gs */ + *type = INSN_STACK; + op->src.type = OP_SRC_CONST; + op->dest.type = OP_DEST_PUSH; + + } else if (op2 == 0xa1 || op2 == 0xa9) { + + /* pop fs/gs */ + *type = INSN_STACK; + op->src.type = OP_SRC_POP; + op->dest.type = OP_DEST_MEM; + }

break;

- case 0xc9: /* leave */ - *type = INSN_FP_RESTORE; + case 0xc9: + /* + * leave + * + * equivalent to: + * mov bp, sp + * pop bp + */ + *type = INSN_STACK; + op->dest.type = OP_DEST_LEAVE; + break;

- case 0xe3: /* jecxz/jrcxz */ + case 0xe3: + /* jecxz/jrcxz */ *type = INSN_JUMP_CONDITIONAL; break;

@@ -158,14 +445,27 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, break;

case 0xff: - ext = X86_MODRM_REG(insn.modrm.bytes[0]); - if (ext == 2 || ext == 3) + if (modrm_reg == 2 || modrm_reg == 3) + *type = INSN_CALL_DYNAMIC; - else if (ext == 4) + + else if (modrm_reg == 4) + *type = INSN_JUMP_DYNAMIC; - else if (ext == 5) /*jmpf */ + + else if (modrm_reg == 5) + + /* jmpf */ *type = INSN_CONTEXT_SWITCH;

+ else if (modrm_reg == 6) { + + /* push from mem */ + *type = INSN_STACK; + op->src.type = OP_SRC_CONST; + op->dest.type = OP_DEST_PUSH; + } + break;

default: @@ -176,3 +476,21 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,

return 0; } + +void arch_initial_func_cfi_state(struct cfi_state *state) +{ + int i; + + for (i = 0; i < CFI_NUM_REGS; i++) { + state->regs[i].base = CFI_UNDEFINED; + state->regs[i].offset = 0; + } + + /* initial CFA (call frame address) */ + state->cfa.base = CFI_SP; + state->cfa.offset = 8; + + /* initial RA (return address) */ + state->regs[16].base = CFI_CFA; + state->regs[16].offset = -8; +} diff --git a/tools/objtool/arch/x86/insn/inat.h b/tools/objtool/arch/x86/include/asm/inat.h similarity index 95% rename from tools/objtool/arch/x86/insn/inat.h rename to tools/objtool/arch/x86/include/asm/inat.h index 125ecd2a300d..1c78580e58be 100644 --- a/tools/objtool/arch/x86/insn/inat.h +++ b/tools/objtool/arch/x86/include/asm/inat.h @@ -20,7 +20,7 @@ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * */ -#include "inat_types.h" +#include <asm/inat_types.h>

/* * Internal bits. Don't use bitmasks directly, because these bits are @@ -97,6 +97,16 @@ #define INAT_MAKE_GROUP(grp) ((grp << INAT_GRP_OFFS) | INAT_MODRM) #define INAT_MAKE_IMM(imm) (imm << INAT_IMM_OFFS)

+/* Identifiers for segment registers */ +#define INAT_SEG_REG_IGNORE 0 +#define INAT_SEG_REG_DEFAULT 1 +#define INAT_SEG_REG_CS 2 +#define INAT_SEG_REG_SS 3 +#define INAT_SEG_REG_DS 4 +#define INAT_SEG_REG_ES 5 +#define INAT_SEG_REG_FS 6 +#define INAT_SEG_REG_GS 7 + /* Attribute search APIs */ extern insn_attr_t inat_get_opcode_attribute(insn_byte_t opcode); extern int inat_get_last_prefix_id(insn_byte_t last_pfx); diff --git a/tools/objtool/arch/x86/insn/inat_types.h b/tools/objtool/arch/x86/include/asm/inat_types.h similarity index 100% rename from tools/objtool/arch/x86/insn/inat_types.h rename to tools/objtool/arch/x86/include/asm/inat_types.h diff --git a/tools/objtool/arch/x86/insn/insn.h b/tools/objtool/arch/x86/include/asm/insn.h similarity index 99% rename from tools/objtool/arch/x86/insn/insn.h rename to tools/objtool/arch/x86/include/asm/insn.h index e23578c7b1be..b3e32b010ab1 100644 --- a/tools/objtool/arch/x86/insn/insn.h +++ b/tools/objtool/arch/x86/include/asm/insn.h @@ -21,7 +21,7 @@ */

/* insn_attr_t is defined in inat.h */ -#include "inat.h" +#include <asm/inat.h>

struct insn_field { union { diff --git a/tools/objtool/arch/x86/include/asm/orc_types.h b/tools/objtool/arch/x86/include/asm/orc_types.h new file mode 100644 index 000000000000..9c9dc579bd7d --- /dev/null +++ b/tools/objtool/arch/x86/include/asm/orc_types.h @@ -0,0 +1,107 @@ +/* + * Copyright (C) 2017 Josh Poimboeuf jpoimboe@redhat.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ + +#ifndef _ORC_TYPES_H +#define _ORC_TYPES_H + +#include <linux/types.h> +#include <linux/compiler.h> + +/* + * The ORC_REG_* registers are base registers which are used to find other + * registers on the stack. + * + * ORC_REG_PREV_SP, also known as DWARF Call Frame Address (CFA), is the + * address of the previous frame: the caller's SP before it called the current + * function. + * + * ORC_REG_UNDEFINED means the corresponding register's value didn't change in + * the current frame. + * + * The most commonly used base registers are SP and BP -- which the previous SP + * is usually based on -- and PREV_SP and UNDEFINED -- which the previous BP is + * usually based on. + * + * The rest of the base registers are needed for special cases like entry code + * and GCC realigned stacks. + */ +#define ORC_REG_UNDEFINED 0 +#define ORC_REG_PREV_SP 1 +#define ORC_REG_DX 2 +#define ORC_REG_DI 3 +#define ORC_REG_BP 4 +#define ORC_REG_SP 5 +#define ORC_REG_R10 6 +#define ORC_REG_R13 7 +#define ORC_REG_BP_INDIRECT 8 +#define ORC_REG_SP_INDIRECT 9 +#define ORC_REG_MAX 15 + +/* + * ORC_TYPE_CALL: Indicates that sp_reg+sp_offset resolves to PREV_SP (the + * caller's SP right before it made the call). Used for all callable + * functions, i.e. all C code and all callable asm functions. + * + * ORC_TYPE_REGS: Used in entry code to indicate that sp_reg+sp_offset points + * to a fully populated pt_regs from a syscall, interrupt, or exception. + * + * ORC_TYPE_REGS_IRET: Used in entry code to indicate that sp_reg+sp_offset + * points to the iret return frame. + * + * The UNWIND_HINT macros are used only for the unwind_hint struct. They + * aren't used in struct orc_entry due to size and complexity constraints. + * Objtool converts them to real types when it converts the hints to orc + * entries. + */ +#define ORC_TYPE_CALL 0 +#define ORC_TYPE_REGS 1 +#define ORC_TYPE_REGS_IRET 2 +#define UNWIND_HINT_TYPE_SAVE 3 +#define UNWIND_HINT_TYPE_RESTORE 4 + +#ifndef __ASSEMBLY__ +/* + * This struct is more or less a vastly simplified version of the DWARF Call + * Frame Information standard. It contains only the necessary parts of DWARF + * CFI, simplified for ease of access by the in-kernel unwinder. It tells the + * unwinder how to find the previous SP and BP (and sometimes entry regs) on + * the stack for a given code address. Each instance of the struct corresponds + * to one or more code locations. + */ +struct orc_entry { + s16 sp_offset; + s16 bp_offset; + unsigned sp_reg:4; + unsigned bp_reg:4; + unsigned type:2; +} __packed; + +/* + * This struct is used by asm and inline asm code to manually annotate the + * location of registers on the stack for the ORC unwinder. + * + * Type can be either ORC_TYPE_* or UNWIND_HINT_TYPE_*. + */ +struct unwind_hint { + u32 ip; + s16 sp_offset; + u8 sp_reg; + u8 type; +}; +#endif /* __ASSEMBLY__ */ + +#endif /* _ORC_TYPES_H */ diff --git a/tools/objtool/arch/x86/insn/inat.c b/tools/objtool/arch/x86/lib/inat.c similarity index 99% rename from tools/objtool/arch/x86/insn/inat.c rename to tools/objtool/arch/x86/lib/inat.c index e4bf28e6f4c7..c1f01a8e9f65 100644 --- a/tools/objtool/arch/x86/insn/inat.c +++ b/tools/objtool/arch/x86/lib/inat.c @@ -18,7 +18,7 @@ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * */ -#include "insn.h" +#include <asm/insn.h>

/* Attribute tables are generated from opcode map */ #include "inat-tables.c" diff --git a/tools/objtool/arch/x86/insn/insn.c b/tools/objtool/arch/x86/lib/insn.c similarity index 99% rename from tools/objtool/arch/x86/insn/insn.c rename to tools/objtool/arch/x86/lib/insn.c index ca983e2bea8b..1088eb8f3a5f 100644 --- a/tools/objtool/arch/x86/insn/insn.c +++ b/tools/objtool/arch/x86/lib/insn.c @@ -23,8 +23,8 @@ #else #include <string.h> #endif -#include "inat.h" -#include "insn.h" +#include <asm/inat.h> +#include <asm/insn.h>

/* Verify next sizeof(t) bytes can be on the same instruction */ #define validate_next(t, insn, n) \ diff --git a/tools/objtool/arch/x86/insn/x86-opcode-map.txt b/tools/objtool/arch/x86/lib/x86-opcode-map.txt similarity index 99% rename from tools/objtool/arch/x86/insn/x86-opcode-map.txt rename to tools/objtool/arch/x86/lib/x86-opcode-map.txt index 1754e094bc28..e0b85930dd77 100644 --- a/tools/objtool/arch/x86/insn/x86-opcode-map.txt +++ b/tools/objtool/arch/x86/lib/x86-opcode-map.txt @@ -607,7 +607,7 @@ fb: psubq Pq,Qq | vpsubq Vx,Hx,Wx (66),(v1) fc: paddb Pq,Qq | vpaddb Vx,Hx,Wx (66),(v1) fd: paddw Pq,Qq | vpaddw Vx,Hx,Wx (66),(v1) fe: paddd Pq,Qq | vpaddd Vx,Hx,Wx (66),(v1) -ff: +ff: UD0 EndTable

Table: 3-byte opcode 1 (0x0f 0x38) @@ -717,7 +717,7 @@ AVXcode: 2 7e: vpermt2d/q Vx,Hx,Wx (66),(ev) 7f: vpermt2ps/d Vx,Hx,Wx (66),(ev) 80: INVEPT Gy,Mdq (66) -81: INVPID Gy,Mdq (66) +81: INVVPID Gy,Mdq (66) 82: INVPCID Gy,Mdq (66) 83: vpmultishiftqb Vx,Hx,Wx (66),(ev) 88: vexpandps/d Vpd,Wpd (66),(ev) @@ -970,6 +970,15 @@ GrpTable: Grp9 EndTable

GrpTable: Grp10 +# all are UD1 +0: UD1 +1: UD1 +2: UD1 +3: UD1 +4: UD1 +5: UD1 +6: UD1 +7: UD1 EndTable

# Grp11A and Grp11B are expressed as Grp11 in Intel SDM @@ -1009,7 +1018,7 @@ GrpTable: Grp15 1: fxstor | RDGSBASE Ry (F3),(11B) 2: vldmxcsr Md (v1) | WRFSBASE Ry (F3),(11B) 3: vstmxcsr Md (v1) | WRGSBASE Ry (F3),(11B) -4: XSAVE +4: XSAVE | ptwrite Ey (F3),(11B) 5: XRSTOR | lfence (11B) 6: XSAVEOPT | clwb (66) | mfence (11B) 7: clflush | clflushopt (66) | sfence (11B) diff --git a/tools/objtool/arch/x86/insn/gen-insn-attr-x86.awk b/tools/objtool/arch/x86/tools/gen-insn-attr-x86.awk similarity index 99% rename from tools/objtool/arch/x86/insn/gen-insn-attr-x86.awk rename to tools/objtool/arch/x86/tools/gen-insn-attr-x86.awk index a3d2c62fd805..b02a36b2c14f 100644 --- a/tools/objtool/arch/x86/insn/gen-insn-attr-x86.awk +++ b/tools/objtool/arch/x86/tools/gen-insn-attr-x86.awk @@ -1,4 +1,5 @@ #!/bin/awk -f +# SPDX-License-Identifier: GPL-2.0 # gen-insn-attr-x86.awk: Instruction attribute table generator # Written by Masami Hiramatsu mhiramat@redhat.com # diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 365c34ecab26..694abc628e9b 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -29,7 +29,7 @@ #include "builtin.h" #include "check.h"

-bool nofp; +bool no_fp, no_unreachable, retpoline, module;

static const char * const check_usage[] = { "objtool check [<options>] file.o", @@ -37,7 +37,10 @@ static const char * const check_usage[] = { };

const struct option check_options[] = { - OPT_BOOLEAN('f', "no-fp", &nofp, "Skip frame pointer validation"), + OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"), + OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"), + OPT_BOOLEAN('r', "retpoline", &retpoline, "Validate retpoline assumptions"), + OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"), OPT_END(), };

@@ -52,5 +55,5 @@ int cmd_check(int argc, const char **argv)

objname = argv[0];

- return check(objname, nofp); + return check(objname, false); } diff --git a/tools/objtool/builtin-orc.c b/tools/objtool/builtin-orc.c new file mode 100644 index 000000000000..77ea2b97117d --- /dev/null +++ b/tools/objtool/builtin-orc.c @@ -0,0 +1,68 @@ +/* + * Copyright (C) 2017 Josh Poimboeuf jpoimboe@redhat.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ + +/* + * objtool orc: + * + * This command analyzes a .o file and adds .orc_unwind and .orc_unwind_ip + * sections to it, which is used by the in-kernel ORC unwinder. + * + * This command is a superset of "objtool check". + */ + +#include <string.h> +#include "builtin.h" +#include "check.h" + + +static const char *orc_usage[] = { + "objtool orc generate [<options>] file.o", + "objtool orc dump file.o", + NULL, +}; + +int cmd_orc(int argc, const char **argv) +{ + const char *objname; + + argc--; argv++; + if (argc <= 0) + usage_with_options(orc_usage, check_options); + + if (!strncmp(argv[0], "gen", 3)) { + argc = parse_options(argc, argv, check_options, orc_usage, 0); + if (argc != 1) + usage_with_options(orc_usage, check_options); + + objname = argv[0]; + + return check(objname, true); + } + + if (!strcmp(argv[0], "dump")) { + if (argc != 2) + usage_with_options(orc_usage, check_options); + + objname = argv[1]; + + return orc_dump(objname); + } + + usage_with_options(orc_usage, check_options); + + return 0; +} diff --git a/tools/objtool/builtin.h b/tools/objtool/builtin.h index 34d2ba78a616..28ff40e19a14 100644 --- a/tools/objtool/builtin.h +++ b/tools/objtool/builtin.h @@ -17,6 +17,12 @@ #ifndef _BUILTIN_H #define _BUILTIN_H

+#include <subcmd/parse-options.h> + +extern const struct option check_options[]; +extern bool no_fp, no_unreachable, retpoline, module; + extern int cmd_check(int argc, const char **argv); +extern int cmd_orc(int argc, const char **argv);

#endif /* _BUILTIN_H */ diff --git a/tools/objtool/cfi.h b/tools/objtool/cfi.h new file mode 100644 index 000000000000..2fe883c665c7 --- /dev/null +++ b/tools/objtool/cfi.h @@ -0,0 +1,55 @@ +/* + * Copyright (C) 2015-2017 Josh Poimboeuf jpoimboe@redhat.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ + +#ifndef _OBJTOOL_CFI_H +#define _OBJTOOL_CFI_H + +#define CFI_UNDEFINED -1 +#define CFI_CFA -2 +#define CFI_SP_INDIRECT -3 +#define CFI_BP_INDIRECT -4 + +#define CFI_AX 0 +#define CFI_DX 1 +#define CFI_CX 2 +#define CFI_BX 3 +#define CFI_SI 4 +#define CFI_DI 5 +#define CFI_BP 6 +#define CFI_SP 7 +#define CFI_R8 8 +#define CFI_R9 9 +#define CFI_R10 10 +#define CFI_R11 11 +#define CFI_R12 12 +#define CFI_R13 13 +#define CFI_R14 14 +#define CFI_R15 15 +#define CFI_RA 16 +#define CFI_NUM_REGS 17 + +struct cfi_reg { + int base; + int offset; +}; + +struct cfi_state { + struct cfi_reg cfa; + struct cfi_reg regs[CFI_NUM_REGS]; +}; + +#endif /* _OBJTOOL_CFI_H */ diff --git a/tools/objtool/check.c b/tools/objtool/check.c index b7a0af57a43d..c8b8b7101c6f 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -18,6 +18,7 @@ #include <string.h> #include <stdlib.h>

+#include "builtin.h" #include "check.h" #include "elf.h" #include "special.h" @@ -25,12 +26,7 @@ #include "warn.h"

#include <linux/hashtable.h> - -#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) - -#define STATE_FP_SAVED 0x1 -#define STATE_FP_SETUP 0x2 -#define STATE_FENTRY 0x4 +#include <linux/kernel.h>

struct alternative { struct list_head list; @@ -38,10 +34,10 @@ struct alternative { };

const char *objname; -static bool nofp; +struct cfi_state initial_func_cfi;

-static struct instruction *find_insn(struct objtool_file *file, - struct section *sec, unsigned long offset) +struct instruction *find_insn(struct objtool_file *file, + struct section *sec, unsigned long offset) { struct instruction *insn;

@@ -57,28 +53,12 @@ static struct instruction *next_insn_same_sec(struct objtool_file *file, { struct instruction *next = list_next_entry(insn, list);

- if (&next->list == &file->insn_list || next->sec != insn->sec) + if (!next || &next->list == &file->insn_list || next->sec != insn->sec) return NULL;

return next; }

-static bool gcov_enabled(struct objtool_file *file) -{ - struct section *sec; - struct symbol *sym; - - list_for_each_entry(sec, &file->elf->sections, list) - list_for_each_entry(sym, &sec->symbol_list, list) - if (!strncmp(sym->name, "__gcov_.", 8)) - return true; - - return false; -} - -#define for_each_insn(file, insn) \ - list_for_each_entry(insn, &file->insn_list, list) - #define func_for_each_insn(file, func, insn) \ for (insn = find_insn(file, func->sec, func->offset); \ insn && &insn->list != &file->insn_list && \ @@ -95,6 +75,9 @@ static bool gcov_enabled(struct objtool_file *file) #define sec_for_each_insn_from(file, insn) \ for (; insn; insn = next_insn_same_sec(file, insn))

+#define sec_for_each_insn_continue(file, insn) \ + for (insn = next_insn_same_sec(file, insn); insn; \ + insn = next_insn_same_sec(file, insn))

/* * Check if the function has been manually whitelisted with the @@ -104,7 +87,6 @@ static bool gcov_enabled(struct objtool_file *file) static bool ignore_func(struct objtool_file *file, struct symbol *func) { struct rela *rela; - struct instruction *insn;

/* check for STACK_FRAME_NON_STANDARD */ if (file->whitelist && file->whitelist->rela) @@ -117,11 +99,6 @@ static bool ignore_func(struct objtool_file *file, struct symbol *func) return true; }

- /* check if it has a context switching instruction */ - func_for_each_insn(file, func, insn) - if (insn->type == INSN_CONTEXT_SWITCH) - return true; - return false; }

@@ -159,7 +136,8 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func, "complete_and_exit", "kvm_spurious_fault", "__reiserfs_panic", - "lbug_with_loc" + "lbug_with_loc", + "fortify_panic", };

if (func->bind == STB_WEAK) @@ -234,6 +212,20 @@ static int dead_end_function(struct objtool_file *file, struct symbol *func) return __dead_end_function(file, func, 0); }

+static void clear_insn_state(struct insn_state *state) +{ + int i; + + memset(state, 0, sizeof(*state)); + state->cfa.base = CFI_UNDEFINED; + for (i = 0; i < CFI_NUM_REGS; i++) { + state->regs[i].base = CFI_UNDEFINED; + state->vals[i].base = CFI_UNDEFINED; + } + state->drap_reg = CFI_UNDEFINED; + state->drap_offset = -1; +} + /* * Call the arch-specific instruction decoder for all the instructions and add * them to the global instruction list. @@ -246,30 +238,42 @@ static int decode_instructions(struct objtool_file *file) struct instruction *insn; int ret;

- list_for_each_entry(sec, &file->elf->sections, list) { + for_each_sec(file, sec) {

if (!(sec->sh.sh_flags & SHF_EXECINSTR)) continue;

+ if (strcmp(sec->name, ".altinstr_replacement") && + strcmp(sec->name, ".altinstr_aux") && + strncmp(sec->name, ".discard.", 9)) + sec->text = true; + for (offset = 0; offset < sec->len; offset += insn->len) { insn = malloc(sizeof(*insn)); + if (!insn) { + WARN("malloc failed"); + return -1; + } memset(insn, 0, sizeof(*insn)); - INIT_LIST_HEAD(&insn->alts); + clear_insn_state(&insn->state); + insn->sec = sec; insn->offset = offset;

ret = arch_decode_instruction(file->elf, sec, offset, sec->len - offset, &insn->len, &insn->type, - &insn->immediate); + &insn->immediate, + &insn->stack_op); if (ret) - return ret; + goto err;

if (!insn->type || insn->type > INSN_LAST) { WARN_FUNC("invalid instruction type %d", insn->sec, insn->offset, insn->type); - return -1; + ret = -1; + goto err; }

hash_add(file->insn_hash, &insn->hash, insn->offset); @@ -293,10 +297,14 @@ static int decode_instructions(struct objtool_file *file) }

return 0; + +err: + free(insn); + return ret; }

/* - * Find all uses of the unreachable() macro, which are code path dead ends. + * Mark "ud2" instructions and manually annotated dead ends. */ static int add_dead_ends(struct objtool_file *file) { @@ -305,13 +313,24 @@ static int add_dead_ends(struct objtool_file *file) struct instruction *insn; bool found;

- sec = find_section_by_name(file->elf, ".rela__unreachable"); + /* + * By default, "ud2" is a dead end unless otherwise annotated, because + * GCC 7 inserts it for certain divide-by-zero cases. + */ + for_each_insn(file, insn) + if (insn->type == INSN_BUG) + insn->dead_end = true; + + /* + * Check for manually annotated dead ends. + */ + sec = find_section_by_name(file->elf, ".rela.discard.unreachable"); if (!sec) - return 0; + goto reachable;

list_for_each_entry(rela, &sec->rela_list, list) { if (rela->sym->type != STT_SECTION) { - WARN("unexpected relocation symbol type in .rela__unreachable"); + WARN("unexpected relocation symbol type in %s", sec->name); return -1; } insn = find_insn(file, rela->sym->sec, rela->addend); @@ -340,6 +359,48 @@ static int add_dead_ends(struct objtool_file *file) insn->dead_end = true; }

+reachable: + /* + * These manually annotated reachable checks are needed for GCC 4.4, + * where the Linux unreachable() macro isn't supported. In that case + * GCC doesn't know the "ud2" is fatal, so it generates code as if it's + * not a dead end. + */ + sec = find_section_by_name(file->elf, ".rela.discard.reachable"); + if (!sec) + return 0; + + list_for_each_entry(rela, &sec->rela_list, list) { + if (rela->sym->type != STT_SECTION) { + WARN("unexpected relocation symbol type in %s", sec->name); + return -1; + } + insn = find_insn(file, rela->sym->sec, rela->addend); + if (insn) + insn = list_prev_entry(insn, list); + else if (rela->addend == rela->sym->sec->len) { + found = false; + list_for_each_entry_reverse(insn, &file->insn_list, list) { + if (insn->sec == rela->sym->sec) { + found = true; + break; + } + } + + if (!found) { + WARN("can't find reachable insn at %s+0x%x", + rela->sym->sec->name, rela->addend); + return -1; + } + } else { + WARN("can't find reachable insn at %s+0x%x", + rela->sym->sec->name, rela->addend); + return -1; + } + + insn->dead_end = false; + } + return 0; }

@@ -352,7 +413,7 @@ static void add_ignores(struct objtool_file *file) struct section *sec; struct symbol *func;

- list_for_each_entry(sec, &file->elf->sections, list) { + for_each_sec(file, sec) { list_for_each_entry(func, &sec->symbol_list, list) { if (func->type != STT_FUNC) continue; @@ -361,7 +422,7 @@ static void add_ignores(struct objtool_file *file) continue;

func_for_each_insn(file, func, insn) - insn->visited = true; + insn->ignore = true; } } } @@ -415,8 +476,7 @@ static int add_jump_destinations(struct objtool_file *file) insn->type != INSN_JUMP_UNCONDITIONAL) continue;

- /* skip ignores */ - if (insn->visited) + if (insn->ignore) continue;

rela = find_rela_by_dest_range(insn->sec, insn->offset, @@ -436,6 +496,7 @@ static int add_jump_destinations(struct objtool_file *file) * disguise, so convert them accordingly. */ insn->type = INSN_JUMP_DYNAMIC; + insn->retpoline_safe = true; continue; } else { /* sibling call */ @@ -483,18 +544,15 @@ static int add_call_destinations(struct objtool_file *file) dest_off = insn->offset + insn->len + insn->immediate; insn->call_dest = find_symbol_by_offset(insn->sec, dest_off); - /* - * FIXME: Thanks to retpolines, it's now considered - * normal for a function to call within itself. So - * disable this warning for now. - */ -#if 0 - if (!insn->call_dest) { - WARN_FUNC("can't find call dest symbol at offset 0x%lx", - insn->sec, insn->offset, dest_off); + + if (!insn->call_dest && !insn->ignore) { + WARN_FUNC("unsupported intra-function call", + insn->sec, insn->offset); + if (retpoline) + WARN("If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE."); return -1; } -#endif + } else if (rela->sym->type == STT_SECTION) { insn->call_dest = find_symbol_by_offset(rela->sym->sec, rela->addend+4); @@ -538,7 +596,7 @@ static int handle_group_alt(struct objtool_file *file, struct instruction *orig_insn, struct instruction **new_insn) { - struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump; + struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump = NULL; unsigned long dest_off;

last_orig_insn = NULL; @@ -554,25 +612,30 @@ static int handle_group_alt(struct objtool_file *file, last_orig_insn = insn; }

- if (!next_insn_same_sec(file, last_orig_insn)) { - WARN("%s: don't know how to handle alternatives at end of section", - special_alt->orig_sec->name); - return -1; - } - - fake_jump = malloc(sizeof(*fake_jump)); - if (!fake_jump) { - WARN("malloc failed"); - return -1; + if (next_insn_same_sec(file, last_orig_insn)) { + fake_jump = malloc(sizeof(*fake_jump)); + if (!fake_jump) { + WARN("malloc failed"); + return -1; + } + memset(fake_jump, 0, sizeof(*fake_jump)); + INIT_LIST_HEAD(&fake_jump->alts); + clear_insn_state(&fake_jump->state); + + fake_jump->sec = special_alt->new_sec; + fake_jump->offset = -1; + fake_jump->type = INSN_JUMP_UNCONDITIONAL; + fake_jump->jump_dest = list_next_entry(last_orig_insn, list); + fake_jump->ignore = true; } - memset(fake_jump, 0, sizeof(*fake_jump)); - INIT_LIST_HEAD(&fake_jump->alts); - fake_jump->sec = special_alt->new_sec; - fake_jump->offset = -1; - fake_jump->type = INSN_JUMP_UNCONDITIONAL; - fake_jump->jump_dest = list_next_entry(last_orig_insn, list);

if (!special_alt->new_len) { + if (!fake_jump) { + WARN("%s: empty alternative at end of section", + special_alt->orig_sec->name); + return -1; + } + *new_insn = fake_jump; return 0; } @@ -585,6 +648,8 @@ static int handle_group_alt(struct objtool_file *file,

last_new_insn = insn;

+ insn->ignore = orig_insn->ignore_alts; + if (insn->type != INSN_JUMP_CONDITIONAL && insn->type != INSN_JUMP_UNCONDITIONAL) continue; @@ -593,8 +658,14 @@ static int handle_group_alt(struct objtool_file *file, continue;

dest_off = insn->offset + insn->len + insn->immediate; - if (dest_off == special_alt->new_off + special_alt->new_len) + if (dest_off == special_alt->new_off + special_alt->new_len) { + if (!fake_jump) { + WARN("%s: alternative jump to end of section", + special_alt->orig_sec->name); + return -1; + } insn->jump_dest = fake_jump; + }

if (!insn->jump_dest) { WARN_FUNC("can't find alternative jump destination", @@ -609,7 +680,8 @@ static int handle_group_alt(struct objtool_file *file, return -1; }

- list_add(&fake_jump->list, &last_new_insn->list); + if (fake_jump) + list_add(&fake_jump->list, &last_new_insn->list);

return 0; } @@ -656,6 +728,7 @@ static int add_special_section_alts(struct objtool_file *file) return ret;

list_for_each_entry_safe(special_alt, tmp, &special_alts, list) { + orig_insn = find_insn(file, special_alt->orig_sec, special_alt->orig_off); if (!orig_insn) { @@ -665,10 +738,6 @@ static int add_special_section_alts(struct objtool_file *file) goto out; }

- /* Ignore retpoline alternatives. */ - if (orig_insn->ignore_alts) - continue; - new_insn = NULL; if (!special_alt->group || special_alt->new_len) { new_insn = find_insn(file, special_alt->new_sec, @@ -784,8 +853,14 @@ static int add_switch_table(struct objtool_file *file, struct symbol *func, * This is a fairly uncommon pattern which is new for GCC 6. As of this * writing, there are 11 occurrences of it in the allmodconfig kernel. * + * As of GCC 7 there are quite a few more of these and the 'in between' code + * is significant. Esp. with KASAN enabled some of the code between the mov + * and jmpq uses .rodata itself, which can confuse things. + * * TODO: Once we have DWARF CFI and smarter instruction decoding logic, * ensure the same register is used in the mov and jump instructions. + * + * NOTE: RETPOLINE made it harder still to decode dynamic jumps. */ static struct rela *find_switch_table(struct objtool_file *file, struct symbol *func, @@ -807,12 +882,25 @@ static struct rela *find_switch_table(struct objtool_file *file, text_rela->addend + 4); if (!rodata_rela) return NULL; + file->ignore_unreachables = true; return rodata_rela; }

/* case 3 */ - func_for_each_insn_continue_reverse(file, func, insn) { + /* + * Backward search using the @first_jump_src links, these help avoid + * much of the 'in between' code. Which avoids us getting confused by + * it. + */ + for (insn = list_prev_entry(insn, list); + + &insn->list != &file->insn_list && + insn->sec == func->sec && + insn->offset >= func->offset; + + insn = insn->first_jump_src ?: list_prev_entry(insn, list)) { + if (insn->type == INSN_JUMP_DYNAMIC) break;

@@ -836,20 +924,42 @@ static struct rela *find_switch_table(struct objtool_file *file, if (find_symbol_containing(file->rodata, text_rela->addend)) continue;

- return find_rela_by_dest(file->rodata, text_rela->addend); + rodata_rela = find_rela_by_dest(file->rodata, text_rela->addend); + if (!rodata_rela) + continue; + + return rodata_rela; }

return NULL; }

+ static int add_func_switch_tables(struct objtool_file *file, struct symbol *func) { - struct instruction *insn, *prev_jump = NULL; + struct instruction *insn, *last = NULL, *prev_jump = NULL; struct rela *rela, *prev_rela = NULL; int ret;

func_for_each_insn(file, func, insn) { + if (!last) + last = insn; + + /* + * Store back-pointers for unconditional forward jumps such + * that find_switch_table() can back-track using those and + * avoid some potentially confusing code. + */ + if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest && + insn->offset > last->offset && + insn->jump_dest->offset > insn->offset && + !insn->jump_dest->first_jump_src) { + + insn->jump_dest->first_jump_src = insn; + last = insn->jump_dest; + } + if (insn->type != INSN_JUMP_DYNAMIC) continue;

@@ -896,7 +1006,7 @@ static int add_switch_table_alts(struct objtool_file *file) if (!file->rodata || !file->rodata->rela) return 0;

- list_for_each_entry(sec, &file->elf->sections, list) { + for_each_sec(file, sec) { list_for_each_entry(func, &sec->symbol_list, list) { if (func->type != STT_FUNC) continue; @@ -910,6 +1020,134 @@ static int add_switch_table_alts(struct objtool_file *file) return 0; }

+static int read_unwind_hints(struct objtool_file *file) +{ + struct section *sec, *relasec; + struct rela *rela; + struct unwind_hint *hint; + struct instruction *insn; + struct cfi_reg *cfa; + int i; + + sec = find_section_by_name(file->elf, ".discard.unwind_hints"); + if (!sec) + return 0; + + relasec = sec->rela; + if (!relasec) { + WARN("missing .rela.discard.unwind_hints section"); + return -1; + } + + if (sec->len % sizeof(struct unwind_hint)) { + WARN("struct unwind_hint size mismatch"); + return -1; + } + + file->hints = true; + + for (i = 0; i < sec->len / sizeof(struct unwind_hint); i++) { + hint = (struct unwind_hint *)sec->data->d_buf + i; + + rela = find_rela_by_dest(sec, i * sizeof(*hint)); + if (!rela) { + WARN("can't find rela for unwind_hints[%d]", i); + return -1; + } + + insn = find_insn(file, rela->sym->sec, rela->addend); + if (!insn) { + WARN("can't find insn for unwind_hints[%d]", i); + return -1; + } + + cfa = &insn->state.cfa; + + if (hint->type == UNWIND_HINT_TYPE_SAVE) { + insn->save = true; + continue; + + } else if (hint->type == UNWIND_HINT_TYPE_RESTORE) { + insn->restore = true; + insn->hint = true; + continue; + } + + insn->hint = true; + + switch (hint->sp_reg) { + case ORC_REG_UNDEFINED: + cfa->base = CFI_UNDEFINED; + break; + case ORC_REG_SP: + cfa->base = CFI_SP; + break; + case ORC_REG_BP: + cfa->base = CFI_BP; + break; + case ORC_REG_SP_INDIRECT: + cfa->base = CFI_SP_INDIRECT; + break; + case ORC_REG_R10: + cfa->base = CFI_R10; + break; + case ORC_REG_R13: + cfa->base = CFI_R13; + break; + case ORC_REG_DI: + cfa->base = CFI_DI; + break; + case ORC_REG_DX: + cfa->base = CFI_DX; + break; + default: + WARN_FUNC("unsupported unwind_hint sp base reg %d", + insn->sec, insn->offset, hint->sp_reg); + return -1; + } + + cfa->offset = hint->sp_offset; + insn->state.type = hint->type; + } + + return 0; +} + +static int read_retpoline_hints(struct objtool_file *file) +{ + struct section *sec; + struct instruction *insn; + struct rela *rela; + + sec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe"); + if (!sec) + return 0; + + list_for_each_entry(rela, &sec->rela_list, list) { + if (rela->sym->type != STT_SECTION) { + WARN("unexpected relocation symbol type in %s", sec->name); + return -1; + } + + insn = find_insn(file, rela->sym->sec, rela->addend); + if (!insn) { + WARN("bad .discard.retpoline_safe entry"); + return -1; + } + + if (insn->type != INSN_JUMP_DYNAMIC && + insn->type != INSN_CALL_DYNAMIC) { + WARN_FUNC("retpoline_safe hint not an indirect jump/call", + insn->sec, insn->offset); + return -1; + } + + insn->retpoline_safe = true; + } + + return 0; +} + static int decode_sections(struct objtool_file *file) { int ret; @@ -932,11 +1170,11 @@ static int decode_sections(struct objtool_file *file) if (ret) return ret;

- ret = add_call_destinations(file); + ret = add_special_section_alts(file); if (ret) return ret;

- ret = add_special_section_alts(file); + ret = add_call_destinations(file); if (ret) return ret;

@@ -944,6 +1182,14 @@ static int decode_sections(struct objtool_file *file) if (ret) return ret;

+ ret = read_unwind_hints(file); + if (ret) + return ret; + + ret = read_retpoline_hints(file); + if (ret) + return ret; + return 0; }

@@ -957,125 +1203,647 @@ static bool is_fentry_call(struct instruction *insn) return false; }

-static bool has_modified_stack_frame(struct instruction *insn) +static bool has_modified_stack_frame(struct insn_state *state) +{ + int i; + + if (state->cfa.base != initial_func_cfi.cfa.base || + state->cfa.offset != initial_func_cfi.cfa.offset || + state->stack_size != initial_func_cfi.cfa.offset || + state->drap) + return true; + + for (i = 0; i < CFI_NUM_REGS; i++) + if (state->regs[i].base != initial_func_cfi.regs[i].base || + state->regs[i].offset != initial_func_cfi.regs[i].offset) + return true; + + return false; +} + +static bool has_valid_stack_frame(struct insn_state *state) +{ + if (state->cfa.base == CFI_BP && state->regs[CFI_BP].base == CFI_CFA && + state->regs[CFI_BP].offset == -16) + return true; + + if (state->drap && state->regs[CFI_BP].base == CFI_BP) + return true; + + return false; +} + +static int update_insn_state_regs(struct instruction *insn, struct insn_state *state) { - return (insn->state & STATE_FP_SAVED) || - (insn->state & STATE_FP_SETUP); + struct cfi_reg *cfa = &state->cfa; + struct stack_op *op = &insn->stack_op; + + if (cfa->base != CFI_SP) + return 0; + + /* push */ + if (op->dest.type == OP_DEST_PUSH) + cfa->offset += 8; + + /* pop */ + if (op->src.type == OP_SRC_POP) + cfa->offset -= 8; + + /* add immediate to sp */ + if (op->dest.type == OP_DEST_REG && op->src.type == OP_SRC_ADD && + op->dest.reg == CFI_SP && op->src.reg == CFI_SP) + cfa->offset -= op->src.offset; + + return 0; }

-static bool has_valid_stack_frame(struct instruction *insn) +static void save_reg(struct insn_state *state, unsigned char reg, int base, + int offset) { - return (insn->state & STATE_FP_SAVED) && - (insn->state & STATE_FP_SETUP); + if (arch_callee_saved_reg(reg) && + state->regs[reg].base == CFI_UNDEFINED) { + state->regs[reg].base = base; + state->regs[reg].offset = offset; + } }

-static unsigned int frame_state(unsigned long state) +static void restore_reg(struct insn_state *state, unsigned char reg) { - return (state & (STATE_FP_SAVED | STATE_FP_SETUP)); + state->regs[reg].base = CFI_UNDEFINED; + state->regs[reg].offset = 0; }

/* - * Follow the branch starting at the given instruction, and recursively follow - * any other branches (jumps). Meanwhile, track the frame pointer state at - * each instruction and validate all the rules described in - * tools/objtool/Documentation/stack-validation.txt. + * A note about DRAP stack alignment: + * + * GCC has the concept of a DRAP register, which is used to help keep track of + * the stack pointer when aligning the stack. r10 or r13 is used as the DRAP + * register. The typical DRAP pattern is: + * + * 4c 8d 54 24 08 lea 0x8(%rsp),%r10 + * 48 83 e4 c0 and $0xffffffffffffffc0,%rsp + * 41 ff 72 f8 pushq -0x8(%r10) + * 55 push %rbp + * 48 89 e5 mov %rsp,%rbp + * (more pushes) + * 41 52 push %r10 + * ... + * 41 5a pop %r10 + * (more pops) + * 5d pop %rbp + * 49 8d 62 f8 lea -0x8(%r10),%rsp + * c3 retq + * + * There are some variations in the epilogues, like: + * + * 5b pop %rbx + * 41 5a pop %r10 + * 41 5c pop %r12 + * 41 5d pop %r13 + * 41 5e pop %r14 + * c9 leaveq + * 49 8d 62 f8 lea -0x8(%r10),%rsp + * c3 retq + * + * and: + * + * 4c 8b 55 e8 mov -0x18(%rbp),%r10 + * 48 8b 5d e0 mov -0x20(%rbp),%rbx + * 4c 8b 65 f0 mov -0x10(%rbp),%r12 + * 4c 8b 6d f8 mov -0x8(%rbp),%r13 + * c9 leaveq + * 49 8d 62 f8 lea -0x8(%r10),%rsp + * c3 retq + * + * Sometimes r13 is used as the DRAP register, in which case it's saved and + * restored beforehand: + * + * 41 55 push %r13 + * 4c 8d 6c 24 10 lea 0x10(%rsp),%r13 + * 48 83 e4 f0 and $0xfffffffffffffff0,%rsp + * ... + * 49 8d 65 f0 lea -0x10(%r13),%rsp + * 41 5d pop %r13 + * c3 retq */ -static int validate_branch(struct objtool_file *file, - struct instruction *first, unsigned char first_state) +static int update_insn_state(struct instruction *insn, struct insn_state *state) { - struct alternative *alt; - struct instruction *insn; - struct section *sec; - struct symbol *func = NULL; - unsigned char state; - int ret; + struct stack_op *op = &insn->stack_op; + struct cfi_reg *cfa = &state->cfa; + struct cfi_reg *regs = state->regs; + + /* stack operations don't make sense with an undefined CFA */ + if (cfa->base == CFI_UNDEFINED) { + if (insn->func) { + WARN_FUNC("undefined stack state", insn->sec, insn->offset); + return -1; + } + return 0; + }

- insn = first; - sec = insn->sec; - state = first_state; + if (state->type == ORC_TYPE_REGS || state->type == ORC_TYPE_REGS_IRET) + return update_insn_state_regs(insn, state);

- if (insn->alt_group && list_empty(&insn->alts)) { - WARN_FUNC("don't know how to handle branch to middle of alternative instruction group", - sec, insn->offset); - return 1; - } + switch (op->dest.type) {

- while (1) { - if (file->c_file && insn->func) { - if (func && func != insn->func) { - WARN("%s() falls through to next function %s()", - func->name, insn->func->name); - return 1; - } + case OP_DEST_REG: + switch (op->src.type) {

- func = insn->func; - } + case OP_SRC_REG: + if (op->src.reg == CFI_SP && op->dest.reg == CFI_BP && + cfa->base == CFI_SP && + regs[CFI_BP].base == CFI_CFA && + regs[CFI_BP].offset == -cfa->offset) {

- if (insn->visited) { - if (frame_state(insn->state) != frame_state(state)) { - WARN_FUNC("frame pointer state mismatch", - sec, insn->offset); - return 1; + /* mov %rsp, %rbp */ + cfa->base = op->dest.reg; + state->bp_scratch = false; }

- return 0; + else if (op->src.reg == CFI_SP && + op->dest.reg == CFI_BP && state->drap) { + + /* drap: mov %rsp, %rbp */ + regs[CFI_BP].base = CFI_BP; + regs[CFI_BP].offset = -state->stack_size; + state->bp_scratch = false; + } + + else if (op->src.reg == CFI_SP && cfa->base == CFI_SP) { + + /* + * mov %rsp, %reg + * + * This is needed for the rare case where GCC + * does: + * + * mov %rsp, %rax + * ... + * mov %rax, %rsp + */ + state->vals[op->dest.reg].base = CFI_CFA; + state->vals[op->dest.reg].offset = -state->stack_size; + } + + else if (op->src.reg == CFI_BP && op->dest.reg == CFI_SP && + cfa->base == CFI_BP) { + + /* + * mov %rbp, %rsp + * + * Restore the original stack pointer (Clang). + */ + state->stack_size = -state->regs[CFI_BP].offset; + } + + else if (op->dest.reg == cfa->base) { + + /* mov %reg, %rsp */ + if (cfa->base == CFI_SP && + state->vals[op->src.reg].base == CFI_CFA) { + + /* + * This is needed for the rare case + * where GCC does something dumb like: + * + * lea 0x8(%rsp), %rcx + * ... + * mov %rcx, %rsp + */ + cfa->offset = -state->vals[op->src.reg].offset; + state->stack_size = cfa->offset; + + } else { + cfa->base = CFI_UNDEFINED; + cfa->offset = 0; + } + } + + break; + + case OP_SRC_ADD: + if (op->dest.reg == CFI_SP && op->src.reg == CFI_SP) { + + /* add imm, %rsp */ + state->stack_size -= op->src.offset; + if (cfa->base == CFI_SP) + cfa->offset -= op->src.offset; + break; + } + + if (op->dest.reg == CFI_SP && op->src.reg == CFI_BP) { + + /* lea disp(%rbp), %rsp */ + state->stack_size = -(op->src.offset + regs[CFI_BP].offset); + break; + } + + if (op->src.reg == CFI_SP && cfa->base == CFI_SP) { + + /* drap: lea disp(%rsp), %drap */ + state->drap_reg = op->dest.reg; + + /* + * lea disp(%rsp), %reg + * + * This is needed for the rare case where GCC + * does something dumb like: + * + * lea 0x8(%rsp), %rcx + * ... + * mov %rcx, %rsp + */ + state->vals[op->dest.reg].base = CFI_CFA; + state->vals[op->dest.reg].offset = \ + -state->stack_size + op->src.offset; + + break; + } + + if (state->drap && op->dest.reg == CFI_SP && + op->src.reg == state->drap_reg) { + + /* drap: lea disp(%drap), %rsp */ + cfa->base = CFI_SP; + cfa->offset = state->stack_size = -op->src.offset; + state->drap_reg = CFI_UNDEFINED; + state->drap = false; + break; + } + + if (op->dest.reg == state->cfa.base) { + WARN_FUNC("unsupported stack register modification", + insn->sec, insn->offset); + return -1; + } + + break; + + case OP_SRC_AND: + if (op->dest.reg != CFI_SP || + (state->drap_reg != CFI_UNDEFINED && cfa->base != CFI_SP) || + (state->drap_reg == CFI_UNDEFINED && cfa->base != CFI_BP)) { + WARN_FUNC("unsupported stack pointer realignment", + insn->sec, insn->offset); + return -1; + } + + if (state->drap_reg != CFI_UNDEFINED) { + /* drap: and imm, %rsp */ + cfa->base = state->drap_reg; + cfa->offset = state->stack_size = 0; + state->drap = true; + } + + /* + * Older versions of GCC (4.8ish) realign the stack + * without DRAP, with a frame pointer. + */ + + break; + + case OP_SRC_POP: + if (!state->drap && op->dest.type == OP_DEST_REG && + op->dest.reg == cfa->base) { + + /* pop %rbp */ + cfa->base = CFI_SP; + } + + if (state->drap && cfa->base == CFI_BP_INDIRECT && + op->dest.type == OP_DEST_REG && + op->dest.reg == state->drap_reg && + state->drap_offset == -state->stack_size) { + + /* drap: pop %drap */ + cfa->base = state->drap_reg; + cfa->offset = 0; + state->drap_offset = -1; + + } else if (regs[op->dest.reg].offset == -state->stack_size) { + + /* pop %reg */ + restore_reg(state, op->dest.reg); + } + + state->stack_size -= 8; + if (cfa->base == CFI_SP) + cfa->offset -= 8; + + break; + + case OP_SRC_REG_INDIRECT: + if (state->drap && op->src.reg == CFI_BP && + op->src.offset == state->drap_offset) { + + /* drap: mov disp(%rbp), %drap */ + cfa->base = state->drap_reg; + cfa->offset = 0; + state->drap_offset = -1; + } + + if (state->drap && op->src.reg == CFI_BP && + op->src.offset == regs[op->dest.reg].offset) { + + /* drap: mov disp(%rbp), %reg */ + restore_reg(state, op->dest.reg); + + } else if (op->src.reg == cfa->base && + op->src.offset == regs[op->dest.reg].offset + cfa->offset) { + + /* mov disp(%rbp), %reg */ + /* mov disp(%rsp), %reg */ + restore_reg(state, op->dest.reg); + } + + break; + + default: + WARN_FUNC("unknown stack-related instruction", + insn->sec, insn->offset); + return -1; }

- insn->visited = true; - insn->state = state; + break;

- list_for_each_entry(alt, &insn->alts, list) { - ret = validate_branch(file, alt->insn, state); - if (ret) + case OP_DEST_PUSH: + state->stack_size += 8; + if (cfa->base == CFI_SP) + cfa->offset += 8; + + if (op->src.type != OP_SRC_REG) + break; + + if (state->drap) { + if (op->src.reg == cfa->base && op->src.reg == state->drap_reg) { + + /* drap: push %drap */ + cfa->base = CFI_BP_INDIRECT; + cfa->offset = -state->stack_size; + + /* save drap so we know when to restore it */ + state->drap_offset = -state->stack_size; + + } else if (op->src.reg == CFI_BP && cfa->base == state->drap_reg) { + + /* drap: push %rbp */ + state->stack_size = 0; + + } else if (regs[op->src.reg].base == CFI_UNDEFINED) { + + /* drap: push %reg */ + save_reg(state, op->src.reg, CFI_BP, -state->stack_size); + } + + } else { + + /* push %reg */ + save_reg(state, op->src.reg, CFI_CFA, -state->stack_size); + } + + /* detect when asm code uses rbp as a scratch register */ + if (!no_fp && insn->func && op->src.reg == CFI_BP && + cfa->base != CFI_BP) + state->bp_scratch = true; + break; + + case OP_DEST_REG_INDIRECT: + + if (state->drap) { + if (op->src.reg == cfa->base && op->src.reg == state->drap_reg) { + + /* drap: mov %drap, disp(%rbp) */ + cfa->base = CFI_BP_INDIRECT; + cfa->offset = op->dest.offset; + + /* save drap offset so we know when to restore it */ + state->drap_offset = op->dest.offset; + } + + else if (regs[op->src.reg].base == CFI_UNDEFINED) { + + /* drap: mov reg, disp(%rbp) */ + save_reg(state, op->src.reg, CFI_BP, op->dest.offset); + } + + } else if (op->dest.reg == cfa->base) { + + /* mov reg, disp(%rbp) */ + /* mov reg, disp(%rsp) */ + save_reg(state, op->src.reg, CFI_CFA, + op->dest.offset - state->cfa.offset); + } + + break; + + case OP_DEST_LEAVE: + if ((!state->drap && cfa->base != CFI_BP) || + (state->drap && cfa->base != state->drap_reg)) { + WARN_FUNC("leave instruction with modified stack frame", + insn->sec, insn->offset); + return -1; + } + + /* leave (mov %rbp, %rsp; pop %rbp) */ + + state->stack_size = -state->regs[CFI_BP].offset - 8; + restore_reg(state, CFI_BP); + + if (!state->drap) { + cfa->base = CFI_SP; + cfa->offset -= 8; + } + + break; + + case OP_DEST_MEM: + if (op->src.type != OP_SRC_POP) { + WARN_FUNC("unknown stack-related memory operation", + insn->sec, insn->offset); + return -1; + } + + /* pop mem */ + state->stack_size -= 8; + if (cfa->base == CFI_SP) + cfa->offset -= 8; + + break; + + default: + WARN_FUNC("unknown stack-related instruction", + insn->sec, insn->offset); + return -1; + } + + return 0; +} + +static bool insn_state_match(struct instruction *insn, struct insn_state *state) +{ + struct insn_state *state1 = &insn->state, *state2 = state; + int i; + + if (memcmp(&state1->cfa, &state2->cfa, sizeof(state1->cfa))) { + WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d", + insn->sec, insn->offset, + state1->cfa.base, state1->cfa.offset, + state2->cfa.base, state2->cfa.offset); + + } else if (memcmp(&state1->regs, &state2->regs, sizeof(state1->regs))) { + for (i = 0; i < CFI_NUM_REGS; i++) { + if (!memcmp(&state1->regs[i], &state2->regs[i], + sizeof(struct cfi_reg))) + continue; + + WARN_FUNC("stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d", + insn->sec, insn->offset, + i, state1->regs[i].base, state1->regs[i].offset, + i, state2->regs[i].base, state2->regs[i].offset); + break; + } + + } else if (state1->type != state2->type) { + WARN_FUNC("stack state mismatch: type1=%d type2=%d", + insn->sec, insn->offset, state1->type, state2->type); + + } else if (state1->drap != state2->drap || + (state1->drap && state1->drap_reg != state2->drap_reg) || + (state1->drap && state1->drap_offset != state2->drap_offset)) { + WARN_FUNC("stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)", + insn->sec, insn->offset, + state1->drap, state1->drap_reg, state1->drap_offset, + state2->drap, state2->drap_reg, state2->drap_offset); + + } else + return true; + + return false; +} + +/* + * Follow the branch starting at the given instruction, and recursively follow + * any other branches (jumps). Meanwhile, track the frame pointer state at + * each instruction and validate all the rules described in + * tools/objtool/Documentation/stack-validation.txt. + */ +static int validate_branch(struct objtool_file *file, struct instruction *first, + struct insn_state state) +{ + struct alternative *alt; + struct instruction *insn, *next_insn; + struct section *sec; + struct symbol *func = NULL; + int ret; + + insn = first; + sec = insn->sec; + + if (insn->alt_group && list_empty(&insn->alts)) { + WARN_FUNC("don't know how to handle branch to middle of alternative instruction group", + sec, insn->offset); + return 1; + } + + while (1) { + next_insn = next_insn_same_sec(file, insn); + + + if (file->c_file && func && insn->func && func != insn->func) { + WARN("%s() falls through to next function %s()", + func->name, insn->func->name); + return 1; + } + + if (insn->func) + func = insn->func; + + if (func && insn->ignore) { + WARN_FUNC("BUG: why am I validating an ignored function?", + sec, insn->offset); + return 1; + } + + if (insn->visited) { + if (!insn->hint && !insn_state_match(insn, &state)) return 1; + + return 0; }

- switch (insn->type) { + if (insn->hint) { + if (insn->restore) { + struct instruction *save_insn, *i; + + i = insn; + save_insn = NULL; + func_for_each_insn_continue_reverse(file, func, i) { + if (i->save) { + save_insn = i; + break; + } + }

- case INSN_FP_SAVE: - if (!nofp) { - if (state & STATE_FP_SAVED) { - WARN_FUNC("duplicate frame pointer save", + if (!save_insn) { + WARN_FUNC("no corresponding CFI save for CFI restore", sec, insn->offset); return 1; } - state |= STATE_FP_SAVED; - } - break;

- case INSN_FP_SETUP: - if (!nofp) { - if (state & STATE_FP_SETUP) { - WARN_FUNC("duplicate frame pointer setup", + if (!save_insn->visited) { + /* + * Oops, no state to copy yet. + * Hopefully we can reach this + * instruction from another branch + * after the save insn has been + * visited. + */ + if (insn == first) + return 0; + + WARN_FUNC("objtool isn't smart enough to handle this CFI save/restore combo", sec, insn->offset); return 1; } - state |= STATE_FP_SETUP; + + insn->state = save_insn->state; } - break;

- case INSN_FP_RESTORE: - if (!nofp) { - if (has_valid_stack_frame(insn)) - state &= ~STATE_FP_SETUP; + state = insn->state; + + } else + insn->state = state; + + insn->visited = true;

- state &= ~STATE_FP_SAVED; + if (!insn->ignore_alts) { + list_for_each_entry(alt, &insn->alts, list) { + ret = validate_branch(file, alt->insn, state); + if (ret) + return 1; } - break; + } + + switch (insn->type) {

case INSN_RETURN: - if (!nofp && has_modified_stack_frame(insn)) { - WARN_FUNC("return without frame pointer restore", + if (func && has_modified_stack_frame(&state)) { + WARN_FUNC("return with modified stack frame", sec, insn->offset); return 1; } + + if (state.bp_scratch) { + WARN("%s uses BP as a scratch register", + insn->func->name); + return 1; + } + return 0;

case INSN_CALL: - if (is_fentry_call(insn)) { - state |= STATE_FENTRY; + if (is_fentry_call(insn)) break; - }

ret = dead_end_function(file, insn->call_dest); if (ret == 1) @@ -1085,7 +1853,7 @@ static int validate_branch(struct objtool_file *file,

/* fallthrough */ case INSN_CALL_DYNAMIC: - if (!nofp && !has_valid_stack_frame(insn)) { + if (!no_fp && func && !has_valid_stack_frame(&state)) { WARN_FUNC("call without frame pointer save/setup", sec, insn->offset); return 1; @@ -1094,16 +1862,19 @@ static int validate_branch(struct objtool_file *file,

case INSN_JUMP_CONDITIONAL: case INSN_JUMP_UNCONDITIONAL: - if (insn->jump_dest) { + if (insn->jump_dest && + (!func || !insn->jump_dest->func || + func == insn->jump_dest->func)) { ret = validate_branch(file, insn->jump_dest, state); if (ret) return 1; - } else if (has_modified_stack_frame(insn)) { - WARN_FUNC("sibling call from callable instruction with changed frame pointer", + + } else if (func && has_modified_stack_frame(&state)) { + WARN_FUNC("sibling call from callable instruction with modified stack frame", sec, insn->offset); return 1; - } /* else it's a sibling call */ + }

if (insn->type == INSN_JUMP_UNCONDITIONAL) return 0; @@ -1111,15 +1882,29 @@ static int validate_branch(struct objtool_file *file, break;

case INSN_JUMP_DYNAMIC: - if (list_empty(&insn->alts) && - has_modified_stack_frame(insn)) { - WARN_FUNC("sibling call from callable instruction with changed frame pointer", + if (func && list_empty(&insn->alts) && + has_modified_stack_frame(&state)) { + WARN_FUNC("sibling call from callable instruction with modified stack frame", sec, insn->offset); return 1; }

return 0;

+ case INSN_CONTEXT_SWITCH: + if (func && (!next_insn || !next_insn->hint)) { + WARN_FUNC("unsupported instruction in callable function", + sec, insn->offset); + return 1; + } + return 0; + + case INSN_STACK: + if (update_insn_state(insn, &state)) + return 1; + + break; + default: break; } @@ -1127,16 +1912,72 @@ static int validate_branch(struct objtool_file *file, if (insn->dead_end) return 0;

- insn = next_insn_same_sec(file, insn); - if (!insn) { + if (!next_insn) { + if (state.cfa.base == CFI_UNDEFINED) + return 0; WARN("%s: unexpected end of section", sec->name); return 1; } + + insn = next_insn; }

return 0; }

+static int validate_unwind_hints(struct objtool_file *file) +{ + struct instruction *insn; + int ret, warnings = 0; + struct insn_state state; + + if (!file->hints) + return 0; + + clear_insn_state(&state); + + for_each_insn(file, insn) { + if (insn->hint && !insn->visited) { + ret = validate_branch(file, insn, state); + warnings += ret; + } + } + + return warnings; +} + +static int validate_retpoline(struct objtool_file *file) +{ + struct instruction *insn; + int warnings = 0; + + for_each_insn(file, insn) { + if (insn->type != INSN_JUMP_DYNAMIC && + insn->type != INSN_CALL_DYNAMIC) + continue; + + if (insn->retpoline_safe) + continue; + + /* + * .init.text code is ran before userspace and thus doesn't + * strictly need retpolines, except for modules which are + * loaded late, they very much do need retpoline in their + * .init.text + */ + if (!strcmp(insn->sec->name, ".init.text") && !module) + continue; + + WARN_FUNC("indirect %s found in RETPOLINE build", + insn->sec, insn->offset, + insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call"); + + warnings++; + } + + return warnings; +} + static bool is_kasan_insn(struct instruction *insn) { return (insn->type == INSN_CALL && @@ -1150,12 +1991,23 @@ static bool is_ubsan_insn(struct instruction *insn) "__ubsan_handle_builtin_unreachable")); }

-static bool ignore_unreachable_insn(struct symbol *func, - struct instruction *insn) +static bool ignore_unreachable_insn(struct instruction *insn) { int i;

- if (insn->type == INSN_NOP) + if (insn->ignore || insn->type == INSN_NOP) + return true; + + /* + * Ignore any unused exceptions. This can happen when a whitelisted + * function has an exception table entry. + * + * Also ignore alternative replacement instructions. This can happen + * when a whitelisted function uses one of the ALTERNATIVE macros. + */ + if (!strcmp(insn->sec->name, ".fixup") || + !strcmp(insn->sec->name, ".altinstr_replacement") || + !strcmp(insn->sec->name, ".altinstr_aux")) return true;

/* @@ -1164,18 +2016,26 @@ static bool ignore_unreachable_insn(struct symbol *func, * * End the search at 5 instructions to avoid going into the weeds. */ + if (!insn->func) + return false; for (i = 0; i < 5; i++) {

if (is_kasan_insn(insn) || is_ubsan_insn(insn)) return true;

- if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest) { - insn = insn->jump_dest; - continue; + if (insn->type == INSN_JUMP_UNCONDITIONAL) { + if (insn->jump_dest && + insn->jump_dest->func == insn->func) { + insn = insn->jump_dest; + continue; + } + + break; }

- if (insn->offset + insn->len >= func->offset + func->len) + if (insn->offset + insn->len >= insn->func->offset + insn->func->len) break; + insn = list_next_entry(insn, list); }

@@ -1187,81 +2047,49 @@ static int validate_functions(struct objtool_file *file) struct section *sec; struct symbol *func; struct instruction *insn; + struct insn_state state; int ret, warnings = 0;

- list_for_each_entry(sec, &file->elf->sections, list) { + clear_insn_state(&state); + + state.cfa = initial_func_cfi.cfa; + memcpy(&state.regs, &initial_func_cfi.regs, + CFI_NUM_REGS * sizeof(struct cfi_reg)); + state.stack_size = initial_func_cfi.cfa.offset; + + for_each_sec(file, sec) { list_for_each_entry(func, &sec->symbol_list, list) { if (func->type != STT_FUNC) continue;

insn = find_insn(file, sec, func->offset); - if (!insn) + if (!insn || insn->ignore) continue;

- ret = validate_branch(file, insn, 0); + ret = validate_branch(file, insn, state); warnings += ret; } }

- list_for_each_entry(sec, &file->elf->sections, list) { - list_for_each_entry(func, &sec->symbol_list, list) { - if (func->type != STT_FUNC) - continue; - - func_for_each_insn(file, func, insn) { - if (insn->visited) - continue; - - insn->visited = true; - - if (file->ignore_unreachables || warnings || - ignore_unreachable_insn(func, insn)) - continue; - - /* - * gcov produces a lot of unreachable - * instructions. If we get an unreachable - * warning and the file has gcov enabled, just - * ignore it, and all other such warnings for - * the file. - */ - if (!file->ignore_unreachables && - gcov_enabled(file)) { - file->ignore_unreachables = true; - continue; - } - - WARN_FUNC("function has unreachable instruction", insn->sec, insn->offset); - warnings++; - } - } - } - return warnings; }

-static int validate_uncallable_instructions(struct objtool_file *file) +static int validate_reachable_instructions(struct objtool_file *file) { struct instruction *insn; - int warnings = 0;

- for_each_insn(file, insn) { - if (!insn->visited && insn->type == INSN_RETURN) { + if (file->ignore_unreachables) + return 0;

- /* - * Don't warn about call instructions in unvisited - * retpoline alternatives. - */ - if (!strcmp(insn->sec->name, ".altinstr_replacement")) - continue; + for_each_insn(file, insn) { + if (insn->visited || ignore_unreachable_insn(insn)) + continue;

- WARN_FUNC("return instruction outside of a callable function", - insn->sec, insn->offset); - warnings++; - } + WARN_FUNC("unreachable instruction", insn->sec, insn->offset); + return 1; }

- return warnings; + return 0; }

static void cleanup(struct objtool_file *file) @@ -1281,42 +2109,73 @@ static void cleanup(struct objtool_file *file) elf_close(file->elf); }

-int check(const char *_objname, bool _nofp) +int check(const char *_objname, bool orc) { struct objtool_file file; int ret, warnings = 0;

objname = _objname; - nofp = _nofp;

- file.elf = elf_open(objname); - if (!file.elf) { - fprintf(stderr, "error reading elf file %s\n", objname); + file.elf = elf_open(objname, orc ? O_RDWR : O_RDONLY); + if (!file.elf) return 1; - }

INIT_LIST_HEAD(&file.insn_list); hash_init(file.insn_hash); file.whitelist = find_section_by_name(file.elf, ".discard.func_stack_frame_non_standard"); file.rodata = find_section_by_name(file.elf, ".rodata"); - file.ignore_unreachables = false; file.c_file = find_section_by_name(file.elf, ".comment"); + file.ignore_unreachables = no_unreachable; + file.hints = false; + + arch_initial_func_cfi_state(&initial_func_cfi);

ret = decode_sections(&file); if (ret < 0) goto out; warnings += ret;

+ if (list_empty(&file.insn_list)) + goto out; + + if (retpoline) { + ret = validate_retpoline(&file); + if (ret < 0) + return ret; + warnings += ret; + } + ret = validate_functions(&file); if (ret < 0) goto out; warnings += ret;

- ret = validate_uncallable_instructions(&file); + ret = validate_unwind_hints(&file); if (ret < 0) goto out; warnings += ret;

+ if (!warnings) { + ret = validate_reachable_instructions(&file); + if (ret < 0) + goto out; + warnings += ret; + } + + if (orc) { + ret = create_orc(&file); + if (ret < 0) + goto out; + + ret = create_orc_sections(&file); + if (ret < 0) + goto out; + + ret = elf_write(file.elf); + if (ret < 0) + goto out; + } + out: cleanup(&file);

diff --git a/tools/objtool/check.h b/tools/objtool/check.h index aca248a049e0..c6b68fcb926f 100644 --- a/tools/objtool/check.h +++ b/tools/objtool/check.h @@ -20,22 +20,40 @@

#include <stdbool.h> #include "elf.h" +#include "cfi.h" #include "arch.h" +#include "orc.h" #include <linux/hashtable.h>

+struct insn_state { + struct cfi_reg cfa; + struct cfi_reg regs[CFI_NUM_REGS]; + int stack_size; + unsigned char type; + bool bp_scratch; + bool drap; + int drap_reg, drap_offset; + struct cfi_reg vals[CFI_NUM_REGS]; +}; + struct instruction { struct list_head list; struct hlist_node hash; struct section *sec; unsigned long offset; - unsigned int len, state; + unsigned int len; unsigned char type; unsigned long immediate; - bool alt_group, visited, dead_end, ignore_alts; + bool alt_group, visited, dead_end, ignore, hint, save, restore, ignore_alts; + bool retpoline_safe; struct symbol *call_dest; struct instruction *jump_dest; + struct instruction *first_jump_src; struct list_head alts; struct symbol *func; + struct stack_op stack_op; + struct insn_state state; + struct orc_entry orc; };

struct objtool_file { @@ -43,9 +61,22 @@ struct objtool_file { struct list_head insn_list; DECLARE_HASHTABLE(insn_hash, 16); struct section *rodata, *whitelist; - bool ignore_unreachables, c_file; + bool ignore_unreachables, c_file, hints; };

-int check(const char *objname, bool nofp); +int check(const char *objname, bool orc); + +struct instruction *find_insn(struct objtool_file *file, + struct section *sec, unsigned long offset); + +#define for_each_insn(file, insn) \ + list_for_each_entry(insn, &file->insn_list, list) + +#define sec_for_each_insn(file, sec, insn) \ + for (insn = find_insn(file, sec, 0); \ + insn && &insn->list != &file->insn_list && \ + insn->sec == sec; \ + insn = list_next_entry(insn, list)) +

#endif /* _CHECK_H */ diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index faacf0c89976..c1c338661699 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -31,13 +31,6 @@ #include "elf.h" #include "warn.h"

-/* - * Fallback for systems without this "read, mmaping if possible" cmd. - */ -#ifndef ELF_C_READ_MMAP -#define ELF_C_READ_MMAP ELF_C_READ -#endif - struct section *find_section_by_name(struct elf *elf, const char *name) { struct section *sec; @@ -140,12 +133,12 @@ static int read_sections(struct elf *elf) int i;

if (elf_getshdrnum(elf->elf, &sections_nr)) { - perror("elf_getshdrnum"); + WARN_ELF("elf_getshdrnum"); return -1; }

if (elf_getshdrstrndx(elf->elf, &shstrndx)) { - perror("elf_getshdrstrndx"); + WARN_ELF("elf_getshdrstrndx"); return -1; }

@@ -166,37 +159,37 @@ static int read_sections(struct elf *elf)

s = elf_getscn(elf->elf, i); if (!s) { - perror("elf_getscn"); + WARN_ELF("elf_getscn"); return -1; }

sec->idx = elf_ndxscn(s);

if (!gelf_getshdr(s, &sec->sh)) { - perror("gelf_getshdr"); + WARN_ELF("gelf_getshdr"); return -1; }

sec->name = elf_strptr(elf->elf, shstrndx, sec->sh.sh_name); if (!sec->name) { - perror("elf_strptr"); - return -1; - } - - sec->elf_data = elf_getdata(s, NULL); - if (!sec->elf_data) { - perror("elf_getdata"); + WARN_ELF("elf_strptr"); return -1; }

- if (sec->elf_data->d_off != 0 || - sec->elf_data->d_size != sec->sh.sh_size) { - WARN("unexpected data attributes for %s", sec->name); - return -1; + if (sec->sh.sh_size != 0) { + sec->data = elf_getdata(s, NULL); + if (!sec->data) { + WARN_ELF("elf_getdata"); + return -1; + } + if (sec->data->d_off != 0 || + sec->data->d_size != sec->sh.sh_size) { + WARN("unexpected data attributes for %s", + sec->name); + return -1; + } } - - sec->data = (unsigned long)sec->elf_data->d_buf; - sec->len = sec->elf_data->d_size; + sec->len = sec->sh.sh_size; }

/* sanity check, one more call to elf_nextscn() should return NULL */ @@ -233,15 +226,15 @@ static int read_symbols(struct elf *elf)

sym->idx = i;

- if (!gelf_getsym(symtab->elf_data, i, &sym->sym)) { - perror("gelf_getsym"); + if (!gelf_getsym(symtab->data, i, &sym->sym)) { + WARN_ELF("gelf_getsym"); goto err; }

sym->name = elf_strptr(elf->elf, symtab->sh.sh_link, sym->sym.st_name); if (!sym->name) { - perror("elf_strptr"); + WARN_ELF("elf_strptr"); goto err; }

@@ -323,8 +316,8 @@ static int read_relas(struct elf *elf) } memset(rela, 0, sizeof(*rela));

- if (!gelf_getrela(sec->elf_data, i, &rela->rela)) { - perror("gelf_getrela"); + if (!gelf_getrela(sec->data, i, &rela->rela)) { + WARN_ELF("gelf_getrela"); return -1; }

@@ -348,9 +341,10 @@ static int read_relas(struct elf *elf) return 0; }

-struct elf *elf_open(const char *name) +struct elf *elf_open(const char *name, int flags) { struct elf *elf; + Elf_Cmd cmd;

elf_version(EV_CURRENT);

@@ -363,27 +357,28 @@ struct elf *elf_open(const char *name)

INIT_LIST_HEAD(&elf->sections);

- elf->name = strdup(name); - if (!elf->name) { - perror("strdup"); - goto err; - } - - elf->fd = open(name, O_RDONLY); + elf->fd = open(name, flags); if (elf->fd == -1) { fprintf(stderr, "objtool: Can't open '%s': %s\n", name, strerror(errno)); goto err; }

- elf->elf = elf_begin(elf->fd, ELF_C_READ_MMAP, NULL); + if ((flags & O_ACCMODE) == O_RDONLY) + cmd = ELF_C_READ_MMAP; + else if ((flags & O_ACCMODE) == O_RDWR) + cmd = ELF_C_RDWR; + else /* O_WRONLY */ + cmd = ELF_C_WRITE; + + elf->elf = elf_begin(elf->fd, cmd, NULL); if (!elf->elf) { - perror("elf_begin"); + WARN_ELF("elf_begin"); goto err; }

if (!gelf_getehdr(elf->elf, &elf->ehdr)) { - perror("gelf_getehdr"); + WARN_ELF("gelf_getehdr"); goto err; }

@@ -403,12 +398,212 @@ struct elf *elf_open(const char *name) return NULL; }

+struct section *elf_create_section(struct elf *elf, const char *name, + size_t entsize, int nr) +{ + struct section *sec, *shstrtab; + size_t size = entsize * nr; + struct Elf_Scn *s; + Elf_Data *data; + + sec = malloc(sizeof(*sec)); + if (!sec) { + perror("malloc"); + return NULL; + } + memset(sec, 0, sizeof(*sec)); + + INIT_LIST_HEAD(&sec->symbol_list); + INIT_LIST_HEAD(&sec->rela_list); + hash_init(sec->rela_hash); + hash_init(sec->symbol_hash); + + list_add_tail(&sec->list, &elf->sections); + + s = elf_newscn(elf->elf); + if (!s) { + WARN_ELF("elf_newscn"); + return NULL; + } + + sec->name = strdup(name); + if (!sec->name) { + perror("strdup"); + return NULL; + } + + sec->idx = elf_ndxscn(s); + sec->len = size; + sec->changed = true; + + sec->data = elf_newdata(s); + if (!sec->data) { + WARN_ELF("elf_newdata"); + return NULL; + } + + sec->data->d_size = size; + sec->data->d_align = 1; + + if (size) { + sec->data->d_buf = malloc(size); + if (!sec->data->d_buf) { + perror("malloc"); + return NULL; + } + memset(sec->data->d_buf, 0, size); + } + + if (!gelf_getshdr(s, &sec->sh)) { + WARN_ELF("gelf_getshdr"); + return NULL; + } + + sec->sh.sh_size = size; + sec->sh.sh_entsize = entsize; + sec->sh.sh_type = SHT_PROGBITS; + sec->sh.sh_addralign = 1; + sec->sh.sh_flags = SHF_ALLOC; + + + /* Add section name to .shstrtab */ + shstrtab = find_section_by_name(elf, ".shstrtab"); + if (!shstrtab) { + WARN("can't find .shstrtab section"); + return NULL; + } + + s = elf_getscn(elf->elf, shstrtab->idx); + if (!s) { + WARN_ELF("elf_getscn"); + return NULL; + } + + data = elf_newdata(s); + if (!data) { + WARN_ELF("elf_newdata"); + return NULL; + } + + data->d_buf = sec->name; + data->d_size = strlen(name) + 1; + data->d_align = 1; + + sec->sh.sh_name = shstrtab->len; + + shstrtab->len += strlen(name) + 1; + shstrtab->changed = true; + + return sec; +} + +struct section *elf_create_rela_section(struct elf *elf, struct section *base) +{ + char *relaname; + struct section *sec; + + relaname = malloc(strlen(base->name) + strlen(".rela") + 1); + if (!relaname) { + perror("malloc"); + return NULL; + } + strcpy(relaname, ".rela"); + strcat(relaname, base->name); + + sec = elf_create_section(elf, relaname, sizeof(GElf_Rela), 0); + free(relaname); + if (!sec) + return NULL; + + base->rela = sec; + sec->base = base; + + sec->sh.sh_type = SHT_RELA; + sec->sh.sh_addralign = 8; + sec->sh.sh_link = find_section_by_name(elf, ".symtab")->idx; + sec->sh.sh_info = base->idx; + sec->sh.sh_flags = SHF_INFO_LINK; + + return sec; +} + +int elf_rebuild_rela_section(struct section *sec) +{ + struct rela *rela; + int nr, idx = 0, size; + GElf_Rela *relas; + + nr = 0; + list_for_each_entry(rela, &sec->rela_list, list) + nr++; + + size = nr * sizeof(*relas); + relas = malloc(size); + if (!relas) { + perror("malloc"); + return -1; + } + + sec->data->d_buf = relas; + sec->data->d_size = size; + + sec->sh.sh_size = size; + + idx = 0; + list_for_each_entry(rela, &sec->rela_list, list) { + relas[idx].r_offset = rela->offset; + relas[idx].r_addend = rela->addend; + relas[idx].r_info = GELF_R_INFO(rela->sym->idx, rela->type); + idx++; + } + + return 0; +} + +int elf_write(struct elf *elf) +{ + struct section *sec; + Elf_Scn *s; + + /* Update section headers for changed sections: */ + list_for_each_entry(sec, &elf->sections, list) { + if (sec->changed) { + s = elf_getscn(elf->elf, sec->idx); + if (!s) { + WARN_ELF("elf_getscn"); + return -1; + } + if (!gelf_update_shdr(s, &sec->sh)) { + WARN_ELF("gelf_update_shdr"); + return -1; + } + } + } + + /* Make sure the new section header entries get updated properly. */ + elf_flagelf(elf->elf, ELF_C_SET, ELF_F_DIRTY); + + /* Write all changes to the file. */ + if (elf_update(elf->elf, ELF_C_WRITE) < 0) { + WARN_ELF("elf_update"); + return -1; + } + + return 0; +} + void elf_close(struct elf *elf) { struct section *sec, *tmpsec; struct symbol *sym, *tmpsym; struct rela *rela, *tmprela;

+ if (elf->elf) + elf_end(elf->elf); + + if (elf->fd > 0) + close(elf->fd); + list_for_each_entry_safe(sec, tmpsec, &elf->sections, list) { list_for_each_entry_safe(sym, tmpsym, &sec->symbol_list, list) { list_del(&sym->list); @@ -423,11 +618,6 @@ void elf_close(struct elf *elf) list_del(&sec->list); free(sec); } - if (elf->name) - free(elf->name); - if (elf->fd > 0) - close(elf->fd); - if (elf->elf) - elf_end(elf->elf); + free(elf); } diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h index 731973e1a3f5..d86e2ff14466 100644 --- a/tools/objtool/elf.h +++ b/tools/objtool/elf.h @@ -28,6 +28,13 @@ # define elf_getshdrstrndx elf_getshstrndx #endif

+/* + * Fallback for systems without this "read, mmaping if possible" cmd. + */ +#ifndef ELF_C_READ_MMAP +#define ELF_C_READ_MMAP ELF_C_READ +#endif + struct section { struct list_head list; GElf_Shdr sh; @@ -37,11 +44,11 @@ struct section { DECLARE_HASHTABLE(rela_hash, 16); struct section *base, *rela; struct symbol *sym; - Elf_Data *elf_data; + Elf_Data *data; char *name; int idx; - unsigned long data; unsigned int len; + bool changed, text; };

struct symbol { @@ -76,7 +83,7 @@ struct elf { };

-struct elf *elf_open(const char *name); +struct elf *elf_open(const char *name, int flags); struct section *find_section_by_name(struct elf *elf, const char *name); struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset); struct symbol *find_symbol_containing(struct section *sec, unsigned long offset); @@ -84,8 +91,14 @@ struct rela *find_rela_by_dest(struct section *sec, unsigned long offset); struct rela *find_rela_by_dest_range(struct section *sec, unsigned long offset, unsigned int len); struct symbol *find_containing_func(struct section *sec, unsigned long offset); +struct section *elf_create_section(struct elf *elf, const char *name, size_t + entsize, int nr); +struct section *elf_create_rela_section(struct elf *elf, struct section *base); +int elf_rebuild_rela_section(struct section *sec); +int elf_write(struct elf *elf); void elf_close(struct elf *elf);

- +#define for_each_sec(file, sec) \ + list_for_each_entry(sec, &file->elf->sections, list)

#endif /* _OBJTOOL_ELF_H */ diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c index 46c326db4f46..07f329919828 100644 --- a/tools/objtool/objtool.c +++ b/tools/objtool/objtool.c @@ -31,11 +31,10 @@ #include <stdlib.h> #include <subcmd/exec-cmd.h> #include <subcmd/pager.h> +#include <linux/kernel.h>

#include "builtin.h"

-#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0])) - struct cmd_struct { const char *name; int (*fn)(int, const char **); @@ -43,10 +42,11 @@ struct cmd_struct { };

static const char objtool_usage_string[] = - "objtool [OPTIONS] COMMAND [ARGS]"; + "objtool COMMAND [ARGS]";

static struct cmd_struct objtool_cmds[] = { {"check", cmd_check, "Perform stack metadata validation on an object file" }, + {"orc", cmd_orc, "Generate in-place ORC unwind tables for an object file" }, };

bool help; @@ -70,7 +70,7 @@ static void cmd_usage(void)

printf("\n");

- exit(1); + exit(129); }

static void handle_options(int *argc, const char ***argv) @@ -86,9 +86,7 @@ static void handle_options(int *argc, const char ***argv) break; } else { fprintf(stderr, "Unknown option: %s\n", cmd); - fprintf(stderr, "\n Usage: %s\n", - objtool_usage_string); - exit(1); + cmd_usage(); }

(*argv)++; diff --git a/tools/objtool/orc.h b/tools/objtool/orc.h new file mode 100644 index 000000000000..b0e92a6d0903 --- /dev/null +++ b/tools/objtool/orc.h @@ -0,0 +1,30 @@ +/* + * Copyright (C) 2017 Josh Poimboeuf jpoimboe@redhat.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ + +#ifndef _ORC_H +#define _ORC_H + +#include <asm/orc_types.h> + +struct objtool_file; + +int create_orc(struct objtool_file *file); +int create_orc_sections(struct objtool_file *file); + +int orc_dump(const char *objname); + +#endif /* _ORC_H */ diff --git a/tools/objtool/orc_dump.c b/tools/objtool/orc_dump.c new file mode 100644 index 000000000000..c3343820916a --- /dev/null +++ b/tools/objtool/orc_dump.c @@ -0,0 +1,213 @@ +/* + * Copyright (C) 2017 Josh Poimboeuf jpoimboe@redhat.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ + +#include <unistd.h> +#include "orc.h" +#include "warn.h" + +static const char *reg_name(unsigned int reg) +{ + switch (reg) { + case ORC_REG_PREV_SP: + return "prevsp"; + case ORC_REG_DX: + return "dx"; + case ORC_REG_DI: + return "di"; + case ORC_REG_BP: + return "bp"; + case ORC_REG_SP: + return "sp"; + case ORC_REG_R10: + return "r10"; + case ORC_REG_R13: + return "r13"; + case ORC_REG_BP_INDIRECT: + return "bp(ind)"; + case ORC_REG_SP_INDIRECT: + return "sp(ind)"; + default: + return "?"; + } +} + +static const char *orc_type_name(unsigned int type) +{ + switch (type) { + case ORC_TYPE_CALL: + return "call"; + case ORC_TYPE_REGS: + return "regs"; + case ORC_TYPE_REGS_IRET: + return "iret"; + default: + return "?"; + } +} + +static void print_reg(unsigned int reg, int offset) +{ + if (reg == ORC_REG_BP_INDIRECT) + printf("(bp%+d)", offset); + else if (reg == ORC_REG_SP_INDIRECT) + printf("(sp%+d)", offset); + else if (reg == ORC_REG_UNDEFINED) + printf("(und)"); + else + printf("%s%+d", reg_name(reg), offset); +} + +int orc_dump(const char *_objname) +{ + int fd, nr_entries, i, *orc_ip = NULL, orc_size = 0; + struct orc_entry *orc = NULL; + char *name; + size_t nr_sections; + Elf64_Addr orc_ip_addr = 0; + size_t shstrtab_idx; + Elf *elf; + Elf_Scn *scn; + GElf_Shdr sh; + GElf_Rela rela; + GElf_Sym sym; + Elf_Data *data, *symtab = NULL, *rela_orc_ip = NULL; + + + objname = _objname; + + elf_version(EV_CURRENT); + + fd = open(objname, O_RDONLY); + if (fd == -1) { + perror("open"); + return -1; + } + + elf = elf_begin(fd, ELF_C_READ_MMAP, NULL); + if (!elf) { + WARN_ELF("elf_begin"); + return -1; + } + + if (elf_getshdrnum(elf, &nr_sections)) { + WARN_ELF("elf_getshdrnum"); + return -1; + } + + if (elf_getshdrstrndx(elf, &shstrtab_idx)) { + WARN_ELF("elf_getshdrstrndx"); + return -1; + } + + for (i = 0; i < nr_sections; i++) { + scn = elf_getscn(elf, i); + if (!scn) { + WARN_ELF("elf_getscn"); + return -1; + } + + if (!gelf_getshdr(scn, &sh)) { + WARN_ELF("gelf_getshdr"); + return -1; + } + + name = elf_strptr(elf, shstrtab_idx, sh.sh_name); + if (!name) { + WARN_ELF("elf_strptr"); + return -1; + } + + data = elf_getdata(scn, NULL); + if (!data) { + WARN_ELF("elf_getdata"); + return -1; + } + + if (!strcmp(name, ".symtab")) { + symtab = data; + } else if (!strcmp(name, ".orc_unwind")) { + orc = data->d_buf; + orc_size = sh.sh_size; + } else if (!strcmp(name, ".orc_unwind_ip")) { + orc_ip = data->d_buf; + orc_ip_addr = sh.sh_addr; + } else if (!strcmp(name, ".rela.orc_unwind_ip")) { + rela_orc_ip = data; + } + } + + if (!symtab || !orc || !orc_ip) + return 0; + + if (orc_size % sizeof(*orc) != 0) { + WARN("bad .orc_unwind section size"); + return -1; + } + + nr_entries = orc_size / sizeof(*orc); + for (i = 0; i < nr_entries; i++) { + if (rela_orc_ip) { + if (!gelf_getrela(rela_orc_ip, i, &rela)) { + WARN_ELF("gelf_getrela"); + return -1; + } + + if (!gelf_getsym(symtab, GELF_R_SYM(rela.r_info), &sym)) { + WARN_ELF("gelf_getsym"); + return -1; + } + + scn = elf_getscn(elf, sym.st_shndx); + if (!scn) { + WARN_ELF("elf_getscn"); + return -1; + } + + if (!gelf_getshdr(scn, &sh)) { + WARN_ELF("gelf_getshdr"); + return -1; + } + + name = elf_strptr(elf, shstrtab_idx, sh.sh_name); + if (!name || !*name) { + WARN_ELF("elf_strptr"); + return -1; + } + + printf("%s+%llx:", name, (unsigned long long)rela.r_addend); + + } else { + printf("%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i])); + } + + + printf(" sp:"); + + print_reg(orc[i].sp_reg, orc[i].sp_offset); + + printf(" bp:"); + + print_reg(orc[i].bp_reg, orc[i].bp_offset); + + printf(" type:%s\n", orc_type_name(orc[i].type)); + } + + elf_end(elf); + close(fd); + + return 0; +} diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c new file mode 100644 index 000000000000..18384d9be4e1 --- /dev/null +++ b/tools/objtool/orc_gen.c @@ -0,0 +1,221 @@ +/* + * Copyright (C) 2017 Josh Poimboeuf jpoimboe@redhat.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ + +#include <stdlib.h> +#include <string.h> + +#include "orc.h" +#include "check.h" +#include "warn.h" + +int create_orc(struct objtool_file *file) +{ + struct instruction *insn; + + for_each_insn(file, insn) { + struct orc_entry *orc = &insn->orc; + struct cfi_reg *cfa = &insn->state.cfa; + struct cfi_reg *bp = &insn->state.regs[CFI_BP]; + + if (cfa->base == CFI_UNDEFINED) { + orc->sp_reg = ORC_REG_UNDEFINED; + continue; + } + + switch (cfa->base) { + case CFI_SP: + orc->sp_reg = ORC_REG_SP; + break; + case CFI_SP_INDIRECT: + orc->sp_reg = ORC_REG_SP_INDIRECT; + break; + case CFI_BP: + orc->sp_reg = ORC_REG_BP; + break; + case CFI_BP_INDIRECT: + orc->sp_reg = ORC_REG_BP_INDIRECT; + break; + case CFI_R10: + orc->sp_reg = ORC_REG_R10; + break; + case CFI_R13: + orc->sp_reg = ORC_REG_R13; + break; + case CFI_DI: + orc->sp_reg = ORC_REG_DI; + break; + case CFI_DX: + orc->sp_reg = ORC_REG_DX; + break; + default: + WARN_FUNC("unknown CFA base reg %d", + insn->sec, insn->offset, cfa->base); + return -1; + } + + switch(bp->base) { + case CFI_UNDEFINED: + orc->bp_reg = ORC_REG_UNDEFINED; + break; + case CFI_CFA: + orc->bp_reg = ORC_REG_PREV_SP; + break; + case CFI_BP: + orc->bp_reg = ORC_REG_BP; + break; + default: + WARN_FUNC("unknown BP base reg %d", + insn->sec, insn->offset, bp->base); + return -1; + } + + orc->sp_offset = cfa->offset; + orc->bp_offset = bp->offset; + orc->type = insn->state.type; + } + + return 0; +} + +static int create_orc_entry(struct section *u_sec, struct section *ip_relasec, + unsigned int idx, struct section *insn_sec, + unsigned long insn_off, struct orc_entry *o) +{ + struct orc_entry *orc; + struct rela *rela; + + if (!insn_sec->sym) { + WARN("missing symbol for section %s", insn_sec->name); + return -1; + } + + /* populate ORC data */ + orc = (struct orc_entry *)u_sec->data->d_buf + idx; + memcpy(orc, o, sizeof(*orc)); + + /* populate rela for ip */ + rela = malloc(sizeof(*rela)); + if (!rela) { + perror("malloc"); + return -1; + } + memset(rela, 0, sizeof(*rela)); + + rela->sym = insn_sec->sym; + rela->addend = insn_off; + rela->type = R_X86_64_PC32; + rela->offset = idx * sizeof(int); + + list_add_tail(&rela->list, &ip_relasec->rela_list); + hash_add(ip_relasec->rela_hash, &rela->hash, rela->offset); + + return 0; +} + +int create_orc_sections(struct objtool_file *file) +{ + struct instruction *insn, *prev_insn; + struct section *sec, *u_sec, *ip_relasec; + unsigned int idx; + + struct orc_entry empty = { + .sp_reg = ORC_REG_UNDEFINED, + .bp_reg = ORC_REG_UNDEFINED, + .type = ORC_TYPE_CALL, + }; + + sec = find_section_by_name(file->elf, ".orc_unwind"); + if (sec) { + WARN("file already has .orc_unwind section, skipping"); + return -1; + } + + /* count the number of needed orcs */ + idx = 0; + for_each_sec(file, sec) { + if (!sec->text) + continue; + + prev_insn = NULL; + sec_for_each_insn(file, sec, insn) { + if (!prev_insn || + memcmp(&insn->orc, &prev_insn->orc, + sizeof(struct orc_entry))) { + idx++; + } + prev_insn = insn; + } + + /* section terminator */ + if (prev_insn) + idx++; + } + if (!idx) + return -1; + + + /* create .orc_unwind_ip and .rela.orc_unwind_ip sections */ + sec = elf_create_section(file->elf, ".orc_unwind_ip", sizeof(int), idx); + if (!sec) + return -1; + + ip_relasec = elf_create_rela_section(file->elf, sec); + if (!ip_relasec) + return -1; + + /* create .orc_unwind section */ + u_sec = elf_create_section(file->elf, ".orc_unwind", + sizeof(struct orc_entry), idx); + + /* populate sections */ + idx = 0; + for_each_sec(file, sec) { + if (!sec->text) + continue; + + prev_insn = NULL; + sec_for_each_insn(file, sec, insn) { + if (!prev_insn || memcmp(&insn->orc, &prev_insn->orc, + sizeof(struct orc_entry))) { + + if (create_orc_entry(u_sec, ip_relasec, idx, + insn->sec, insn->offset, + &insn->orc)) + return -1; + + idx++; + } + prev_insn = insn; + } + + /* section terminator */ + if (prev_insn) { + if (create_orc_entry(u_sec, ip_relasec, idx, + prev_insn->sec, + prev_insn->offset + prev_insn->len, + &empty)) + return -1; + + idx++; + } + } + + if (elf_rebuild_rela_section(ip_relasec)) + return -1; + + return 0; +} diff --git a/tools/objtool/special.c b/tools/objtool/special.c index bff8abb3a4aa..84f001d52322 100644 --- a/tools/objtool/special.c +++ b/tools/objtool/special.c @@ -91,16 +91,16 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry, alt->jump_or_nop = entry->jump_or_nop;

if (alt->group) { - alt->orig_len = *(unsigned char *)(sec->data + offset + + alt->orig_len = *(unsigned char *)(sec->data->d_buf + offset + entry->orig_len); - alt->new_len = *(unsigned char *)(sec->data + offset + + alt->new_len = *(unsigned char *)(sec->data->d_buf + offset + entry->new_len); }

if (entry->feature) { unsigned short feature;

- feature = *(unsigned short *)(sec->data + offset + + feature = *(unsigned short *)(sec->data->d_buf + offset + entry->feature);

/* diff --git a/tools/objtool/sync-check.sh b/tools/objtool/sync-check.sh new file mode 100644 index 000000000000..1470e74e9d66 --- /dev/null +++ b/tools/objtool/sync-check.sh @@ -0,0 +1,29 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +FILES=' +arch/x86/lib/insn.c +arch/x86/lib/inat.c +arch/x86/lib/x86-opcode-map.txt +arch/x86/tools/gen-insn-attr-x86.awk +arch/x86/include/asm/insn.h +arch/x86/include/asm/inat.h +arch/x86/include/asm/inat_types.h +arch/x86/include/asm/orc_types.h +' + +check() +{ + local file=$1 + + diff $file ../../$file > /dev/null || + echo "Warning: synced file at 'tools/objtool/$file' differs from latest kernel version at '$file'" +} + +if [ ! -d ../../kernel ] || [ ! -d ../../tools ] || [ ! -d ../objtool ]; then + exit 0 +fi + +for i in $FILES; do + check $i +done diff --git a/tools/objtool/warn.h b/tools/objtool/warn.h index ac7e07523e84..afd9f7a05f6d 100644 --- a/tools/objtool/warn.h +++ b/tools/objtool/warn.h @@ -18,6 +18,13 @@ #ifndef _WARN_H #define _WARN_H

+#include <stdlib.h> +#include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include "elf.h" + extern const char *objname;

static inline char *offstr(struct section *sec, unsigned long offset) @@ -57,4 +64,7 @@ static inline char *offstr(struct section *sec, unsigned long offset) free(_str); \ })

+#define WARN_ELF(format, ...) \ + WARN(format ": %s", ##__VA_ARGS__, elf_errmsg(-1)) + #endif /* _WARN_H */

From: Josh Poimboeuf jpoimboe@redhat.com

commit fd35c88b74170d9335530d9abf271d5d73eb5401 upstream.

With GCC 8, some issues were found with the objtool switch table detection.

1) In the .rodata section, immediately after the switch table, there can be another object which contains a pointer to the function which had the switch statement. In this case objtool wrongly considers the function pointer to be part of the switch table. Fix it by:

a) making sure there are no pointers to the beginning of the function; and

b) making sure there are no gaps in the switch table.

Only the former was needed, the latter adds additional protection for future optimizations.

2) In find_switch_table(), case 1 and case 2 are missing the check to ensure that the .rodata switch table data is anonymous, i.e. that it isn't already associated with an ELF symbol. Fix it by adding the same find_symbol_containing() check which is used for case 3.

This fixes the following warnings with GCC 8:

drivers/block/virtio_blk.o: warning: objtool: virtio_queue_rq()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+72 net/ipv6/icmp.o: warning: objtool: icmpv6_rcv()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+64 drivers/usb/core/quirks.o: warning: objtool: quirks_param_set()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+48 drivers/mtd/nand/raw/nand_hynix.o: warning: objtool: hynix_nand_decode_id()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+24 drivers/mtd/nand/raw/nand_samsung.o: warning: objtool: samsung_nand_decode_id()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+32 drivers/gpu/drm/nouveau/nvkm/subdev/top/gk104.o: warning: objtool: gk104_top_oneinit()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+64

Reported-by: Arnd Bergmann arnd@arndb.de Reported-by: kbuild test robot lkp@intel.com Signed-off-by: Josh Poimboeuf jpoimboe@redhat.com Acked-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: David Laight David.Laight@ACULAB.COM Cc: Greg KH gregkh@linuxfoundation.org Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Randy Dunlap rdunlap@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Cc: damian damian.tometzki@icloud.com Link: http://lkml.kernel.org/r/20180510224849.xwi34d6tzheb5wgw@treble Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/objtool/check.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 3126760180c4..063afbdec42d 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -805,17 +805,28 @@ static int add_switch_table(struct objtool_file *file, struct instruction *insn, struct rela *rela = table; struct instruction *alt_insn; struct alternative *alt; + struct symbol *pfunc = insn->func->pfunc; + unsigned int prev_offset = 0;

list_for_each_entry_from(rela, &file->rodata->rela->rela_list, list) { if (rela == next_table) break;

+ /* Make sure the switch table entries are consecutive: */ + if (prev_offset && rela->offset != prev_offset + 8) + break; + + /* Detect function pointers from contiguous objects: */ + if (rela->sym->sec == pfunc->sec && + rela->addend == pfunc->offset) + break; + alt_insn = find_insn(file, rela->sym->sec, rela->addend); if (!alt_insn) break;

/* Make sure the jmp dest is in the function or subfunction: */ - if (alt_insn->func->pfunc != insn->func->pfunc) + if (alt_insn->func->pfunc != pfunc) break;

alt = malloc(sizeof(*alt)); @@ -826,6 +837,13 @@ static int add_switch_table(struct objtool_file *file, struct instruction *insn,

alt->insn = alt_insn; list_add_tail(&alt->list, &insn->alts); + prev_offset = rela->offset; + } + + if (!prev_offset) { + WARN_FUNC("can't find switch jump table", + insn->sec, insn->offset); + return -1; }

return 0; @@ -882,7 +900,9 @@ static struct rela *find_switch_table(struct objtool_file *file, struct instruction *orig_insn = insn;

text_rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len); - if (text_rela && text_rela->sym == file->rodata->sym) { + if (text_rela && text_rela->sym == file->rodata->sym && + !find_symbol_containing(file->rodata, text_rela->addend)) { + /* case 1 */ rodata_rela = find_rela_by_dest(file->rodata, text_rela->addend);

From: Josh Poimboeuf jpoimboe@redhat.com

commit 7dec80ccbe310fb7e225bf21c48c672bb780ce7b upstream.

With the following commit:

fd35c88b7417 ("objtool: Support GCC 8 switch tables")

I added a "can't find switch jump table" warning, to stop covering up silent failures if add_switch_table() can't find anything.

That warning found yet another bug in the objtool switch table detection logic. For cases 1 and 2 (as described in the comments of find_switch_table()), the find_symbol_containing() check doesn't adjust the offset for RIP-relative switch jumps.

Incidentally, this bug was already fixed for case 3 with:

6f5ec2993b1f ("objtool: Detect RIP-relative switch table references")

However, that commit missed the fix for cases 1 and 2.

The different cases are now starting to look more and more alike. So fix the bug by consolidating them into a single case, by checking the original dynamic jump instruction in the case 3 loop.

This also simplifies the code and makes it more robust against future switch table detection issues -- of which I'm sure there will be many...

Switch table detection has been the most fragile area of objtool, by far. I long for the day when we'll have a GCC plugin for annotating switch tables. Linus asked me to delay such a plugin due to the flakiness of the plugin infrastructure in older versions of GCC, so this rickety code is what we're stuck with for now. At least the code is now a little simpler than it was.

Reported-by: kbuild test robot lkp@intel.com Signed-off-by: Josh Poimboeuf jpoimboe@redhat.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Link: http://lkml.kernel.org/r/f400541613d45689086329432f3095119ffbc328.1526674218... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/objtool/check.c | 37 ++++++++++++------------------------- 1 file changed, 12 insertions(+), 25 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 27c79e4d274c..2299eae155ac 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -900,40 +900,19 @@ static struct rela *find_switch_table(struct objtool_file *file, struct instruction *orig_insn = insn; unsigned long table_offset;

- /* case 1 & 2 */ - text_rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len); - if (text_rela && text_rela->sym == file->rodata->sym && - !find_symbol_containing(file->rodata, text_rela->addend)) { - - table_offset = text_rela->addend; - if (text_rela->type == R_X86_64_PC32) { - /* case 2 */ - table_offset += 4; - file->ignore_unreachables = true; - } - - rodata_rela = find_rela_by_dest(file->rodata, table_offset); - if (!rodata_rela) - return NULL; - - return rodata_rela; - } - - /* case 3 */ /* * Backward search using the @first_jump_src links, these help avoid * much of the 'in between' code. Which avoids us getting confused by * it. */ - for (insn = list_prev_entry(insn, list); - + for (; &insn->list != &file->insn_list && insn->sec == func->sec && insn->offset >= func->offset;

insn = insn->first_jump_src ?: list_prev_entry(insn, list)) {

- if (insn->type == INSN_JUMP_DYNAMIC) + if (insn != orig_insn && insn->type == INSN_JUMP_DYNAMIC) break;

/* allow small jumps within the range */ @@ -960,10 +939,18 @@ static struct rela *find_switch_table(struct objtool_file *file, if (find_symbol_containing(file->rodata, table_offset)) continue;

- /* mov [rodata addr], %reg */ rodata_rela = find_rela_by_dest(file->rodata, table_offset); - if (rodata_rela) + if (rodata_rela) { + /* + * Use of RIP-relative switch jumps is quite rare, and + * indicates a rare GCC quirk/bug which can leave dead + * code behind. + */ + if (text_rela->type == R_X86_64_PC32) + file->ignore_unreachables = true; + return rodata_rela; + } }

return NULL;

From: Josh Poimboeuf jpoimboe@redhat.com

commit c207aee48037abca71c669cbec407b9891965c34 upstream.

In preparation for an objtool rewrite which will have broader checks, whitelist functions and files which cause problems because they do unusual things with the stack.

These whitelists serve as a TODO list for which functions and files don't yet have undwarf unwinder coverage. Eventually most of the whitelists can be removed in favor of manual CFI hint annotations or objtool improvements.

Signed-off-by: Josh Poimboeuf jpoimboe@redhat.com Cc: Andy Lutomirski luto@kernel.org Cc: Jiri Slaby jslaby@suse.cz Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/7f934a5d707a574bda33ea282e9478e627fb1829.1498659915... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/crypto/Makefile | 2 ++ arch/x86/crypto/sha1-mb/Makefile | 2 ++ arch/x86/crypto/sha256-mb/Makefile | 2 ++ arch/x86/kernel/Makefile | 1 + arch/x86/kernel/acpi/Makefile | 2 ++ arch/x86/kernel/kprobes/opt.c | 9 ++++++++- arch/x86/kernel/reboot.c | 2 ++ arch/x86/kvm/svm.c | 2 ++ arch/x86/kvm/vmx.c | 3 +++ arch/x86/lib/msr-reg.S | 8 ++++---- arch/x86/net/Makefile | 2 ++ arch/x86/platform/efi/Makefile | 1 + arch/x86/power/Makefile | 2 ++ arch/x86/xen/Makefile | 3 +++ kernel/kexec_core.c | 4 +++- 15 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/arch/x86/crypto/Makefile b/arch/x86/crypto/Makefile index 34b3fa2889d1..9e32d40d71bd 100644 --- a/arch/x86/crypto/Makefile +++ b/arch/x86/crypto/Makefile @@ -2,6 +2,8 @@ # Arch-specific CryptoAPI modules. #

+OBJECT_FILES_NON_STANDARD := y + avx_supported := $(call as-instr,vpxor %xmm0$(comma)%xmm0$(comma)%xmm0,yes,no) avx2_supported := $(call as-instr,vpgatherdd %ymm0$(comma)(%eax$(comma)%ymm1\ $(comma)4)$(comma)%ymm2,yes,no) diff --git a/arch/x86/crypto/sha1-mb/Makefile b/arch/x86/crypto/sha1-mb/Makefile index 2f8756375df5..2e14acc3da25 100644 --- a/arch/x86/crypto/sha1-mb/Makefile +++ b/arch/x86/crypto/sha1-mb/Makefile @@ -2,6 +2,8 @@ # Arch-specific CryptoAPI modules. #

+OBJECT_FILES_NON_STANDARD := y + avx2_supported := $(call as-instr,vpgatherdd %ymm0$(comma)(%eax$(comma)%ymm1\ $(comma)4)$(comma)%ymm2,yes,no) ifeq ($(avx2_supported),yes) diff --git a/arch/x86/crypto/sha256-mb/Makefile b/arch/x86/crypto/sha256-mb/Makefile index 41089e7c400c..45b4fca6c4a8 100644 --- a/arch/x86/crypto/sha256-mb/Makefile +++ b/arch/x86/crypto/sha256-mb/Makefile @@ -2,6 +2,8 @@ # Arch-specific CryptoAPI modules. #

+OBJECT_FILES_NON_STANDARD := y + avx2_supported := $(call as-instr,vpgatherdd %ymm0$(comma)(%eax$(comma)%ymm1\ $(comma)4)$(comma)%ymm2,yes,no) ifeq ($(avx2_supported),yes) diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 79076d75bdbf..4c9c61517613 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -29,6 +29,7 @@ OBJECT_FILES_NON_STANDARD_head_$(BITS).o := y OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o := y OBJECT_FILES_NON_STANDARD_mcount_$(BITS).o := y OBJECT_FILES_NON_STANDARD_test_nx.o := y +OBJECT_FILES_NON_STANDARD_paravirt_patch_$(BITS).o := y

# If instrumentation of this dir is enabled, boot hangs during first second. # Probably could be more selective here, but note that files related to irqs, diff --git a/arch/x86/kernel/acpi/Makefile b/arch/x86/kernel/acpi/Makefile index 26b78d86f25a..85a9e17e0dbc 100644 --- a/arch/x86/kernel/acpi/Makefile +++ b/arch/x86/kernel/acpi/Makefile @@ -1,3 +1,5 @@ +OBJECT_FILES_NON_STANDARD_wakeup_$(BITS).o := y + obj-$(CONFIG_ACPI) += boot.o obj-$(CONFIG_ACPI_SLEEP) += sleep.o wakeup_$(BITS).o obj-$(CONFIG_ACPI_APEI) += apei.o diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index fa671b90c374..1808a9cc7701 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -28,6 +28,7 @@ #include <linux/kdebug.h> #include <linux/kallsyms.h> #include <linux/ftrace.h> +#include <linux/frame.h>

#include <asm/text-patching.h> #include <asm/cacheflush.h> @@ -91,6 +92,7 @@ static void synthesize_set_arg1(kprobe_opcode_t *addr, unsigned long val) }

asm ( + "optprobe_template_func:\n" ".global optprobe_template_entry\n" "optprobe_template_entry:\n" #ifdef CONFIG_X86_64 @@ -128,7 +130,12 @@ asm ( " popf\n" #endif ".global optprobe_template_end\n" - "optprobe_template_end:\n"); + "optprobe_template_end:\n" + ".type optprobe_template_func, @function\n" + ".size optprobe_template_func, .-optprobe_template_func\n"); + +void optprobe_template_func(void); +STACK_FRAME_NON_STANDARD(optprobe_template_func);

#define TMPL_MOVE_IDX \ ((long)&optprobe_template_val - (long)&optprobe_template_entry) diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index 03f21dbfaa9d..4a12362a194a 100644 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -9,6 +9,7 @@ #include <linux/sched.h> #include <linux/tboot.h> #include <linux/delay.h> +#include <linux/frame.h> #include <acpi/reboot.h> #include <asm/io.h> #include <asm/apic.h> @@ -127,6 +128,7 @@ void __noreturn machine_real_restart(unsigned int type) #ifdef CONFIG_APM_MODULE EXPORT_SYMBOL(machine_real_restart); #endif +STACK_FRAME_NON_STANDARD(machine_real_restart);

/* * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index a27f9e442ffc..c4cd1280ac3e 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -36,6 +36,7 @@ #include <linux/slab.h> #include <linux/amd-iommu.h> #include <linux/hashtable.h> +#include <linux/frame.h>

#include <asm/apic.h> #include <asm/perf_event.h> @@ -5111,6 +5112,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)

mark_all_clean(svm->vmcb); } +STACK_FRAME_NON_STANDARD(svm_vcpu_run);

static void svm_set_cr3(struct kvm_vcpu *vcpu, unsigned long root) { diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 2827a9622d97..4a66a620fc17 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -33,6 +33,7 @@ #include <linux/slab.h> #include <linux/tboot.h> #include <linux/hrtimer.h> +#include <linux/frame.h> #include <linux/nospec.h> #include "kvm_cache_regs.h" #include "x86.h" @@ -8698,6 +8699,7 @@ static void vmx_handle_external_intr(struct kvm_vcpu *vcpu) ); } } +STACK_FRAME_NON_STANDARD(vmx_handle_external_intr);

static bool vmx_has_emulated_msr(int index) { @@ -9138,6 +9140,7 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) vmx_recover_nmi_blocking(vmx); vmx_complete_interrupts(vmx); } +STACK_FRAME_NON_STANDARD(vmx_vcpu_run);

static void vmx_load_vmcs01(struct kvm_vcpu *vcpu) { diff --git a/arch/x86/lib/msr-reg.S b/arch/x86/lib/msr-reg.S index c81556409bbb..10ffa7e8519f 100644 --- a/arch/x86/lib/msr-reg.S +++ b/arch/x86/lib/msr-reg.S @@ -13,14 +13,14 @@ .macro op_safe_regs op ENTRY(\op()_safe_regs) pushq %rbx - pushq %rbp + pushq %r12 movq %rdi, %r10 /* Save pointer */ xorl %r11d, %r11d /* Return value */ movl (%rdi), %eax movl 4(%rdi), %ecx movl 8(%rdi), %edx movl 12(%rdi), %ebx - movl 20(%rdi), %ebp + movl 20(%rdi), %r12d movl 24(%rdi), %esi movl 28(%rdi), %edi 1: \op @@ -29,10 +29,10 @@ ENTRY(\op()_safe_regs) movl %ecx, 4(%r10) movl %edx, 8(%r10) movl %ebx, 12(%r10) - movl %ebp, 20(%r10) + movl %r12d, 20(%r10) movl %esi, 24(%r10) movl %edi, 28(%r10) - popq %rbp + popq %r12 popq %rbx ret 3: diff --git a/arch/x86/net/Makefile b/arch/x86/net/Makefile index 90568c33ddb0..fefb4b619598 100644 --- a/arch/x86/net/Makefile +++ b/arch/x86/net/Makefile @@ -1,4 +1,6 @@ # # Arch-specific network modules # +OBJECT_FILES_NON_STANDARD_bpf_jit.o += y + obj-$(CONFIG_BPF_JIT) += bpf_jit.o bpf_jit_comp.o diff --git a/arch/x86/platform/efi/Makefile b/arch/x86/platform/efi/Makefile index 066619b0700c..7a255022933e 100644 --- a/arch/x86/platform/efi/Makefile +++ b/arch/x86/platform/efi/Makefile @@ -1,4 +1,5 @@ OBJECT_FILES_NON_STANDARD_efi_thunk_$(BITS).o := y +OBJECT_FILES_NON_STANDARD_efi_stub_$(BITS).o := y

obj-$(CONFIG_EFI) += quirks.o efi.o efi_$(BITS).o efi_stub_$(BITS).o obj-$(CONFIG_ACPI_BGRT) += efi-bgrt.o diff --git a/arch/x86/power/Makefile b/arch/x86/power/Makefile index a6a198c33623..05041871ac90 100644 --- a/arch/x86/power/Makefile +++ b/arch/x86/power/Makefile @@ -1,3 +1,5 @@ +OBJECT_FILES_NON_STANDARD_hibernate_asm_$(BITS).o := y + # __restore_processor_state() restores %gs after S3 resume and so should not # itself be stack-protected nostackp := $(call cc-option, -fno-stack-protector) diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile index e47e52787d32..4a54059f42ba 100644 --- a/arch/x86/xen/Makefile +++ b/arch/x86/xen/Makefile @@ -1,3 +1,6 @@ +OBJECT_FILES_NON_STANDARD_xen-asm_$(BITS).o := y +OBJECT_FILES_NON_STANDARD_xen-pvh.o := y + ifdef CONFIG_FUNCTION_TRACER # Do not profile debug and lowlevel utilities CFLAGS_REMOVE_spinlock.o = -pg diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 561675589511..f5ab72ebda11 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -38,6 +38,7 @@ #include <linux/syscore_ops.h> #include <linux/compiler.h> #include <linux/hugetlb.h> +#include <linux/frame.h>

#include <asm/page.h> #include <asm/sections.h> @@ -878,7 +879,7 @@ int kexec_load_disabled; * only when panic_cpu holds the current CPU number; this is the only CPU * which processes crash_kexec routines. */ -void __crash_kexec(struct pt_regs *regs) +void __noclone __crash_kexec(struct pt_regs *regs) { /* Take the kexec_mutex here to prevent sys_kexec_load * running on one cpu from replacing the crash kernel @@ -900,6 +901,7 @@ void __crash_kexec(struct pt_regs *regs) mutex_unlock(&kexec_mutex); } } +STACK_FRAME_NON_STANDARD(__crash_kexec);

void crash_kexec(struct pt_regs *regs) {

When building tools/objtool/ it rightly complains about a number of files being out of sync. Fix this up by syncing them properly with the relevant in-kernel versions.

Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/objtool/arch/x86/include/asm/inat.h | 10 ---------- tools/objtool/arch/x86/include/asm/orc_types.h | 2 +- tools/objtool/arch/x86/lib/x86-opcode-map.txt | 15 +++------------ .../objtool/arch/x86/tools/gen-insn-attr-x86.awk | 1 - 4 files changed, 4 insertions(+), 24 deletions(-)

diff --git a/tools/objtool/arch/x86/include/asm/inat.h b/tools/objtool/arch/x86/include/asm/inat.h index 1c78580e58be..02aff0867211 100644 --- a/tools/objtool/arch/x86/include/asm/inat.h +++ b/tools/objtool/arch/x86/include/asm/inat.h @@ -97,16 +97,6 @@ #define INAT_MAKE_GROUP(grp) ((grp << INAT_GRP_OFFS) | INAT_MODRM) #define INAT_MAKE_IMM(imm) (imm << INAT_IMM_OFFS)

-/* Identifiers for segment registers */ -#define INAT_SEG_REG_IGNORE 0 -#define INAT_SEG_REG_DEFAULT 1 -#define INAT_SEG_REG_CS 2 -#define INAT_SEG_REG_SS 3 -#define INAT_SEG_REG_DS 4 -#define INAT_SEG_REG_ES 5 -#define INAT_SEG_REG_FS 6 -#define INAT_SEG_REG_GS 7 - /* Attribute search APIs */ extern insn_attr_t inat_get_opcode_attribute(insn_byte_t opcode); extern int inat_get_last_prefix_id(insn_byte_t last_pfx); diff --git a/tools/objtool/arch/x86/include/asm/orc_types.h b/tools/objtool/arch/x86/include/asm/orc_types.h index 9c9dc579bd7d..7dc777a6cb40 100644 --- a/tools/objtool/arch/x86/include/asm/orc_types.h +++ b/tools/objtool/arch/x86/include/asm/orc_types.h @@ -88,7 +88,7 @@ struct orc_entry { unsigned sp_reg:4; unsigned bp_reg:4; unsigned type:2; -} __packed; +};

/* * This struct is used by asm and inline asm code to manually annotate the diff --git a/tools/objtool/arch/x86/lib/x86-opcode-map.txt b/tools/objtool/arch/x86/lib/x86-opcode-map.txt index e0b85930dd77..1754e094bc28 100644 --- a/tools/objtool/arch/x86/lib/x86-opcode-map.txt +++ b/tools/objtool/arch/x86/lib/x86-opcode-map.txt @@ -607,7 +607,7 @@ fb: psubq Pq,Qq | vpsubq Vx,Hx,Wx (66),(v1) fc: paddb Pq,Qq | vpaddb Vx,Hx,Wx (66),(v1) fd: paddw Pq,Qq | vpaddw Vx,Hx,Wx (66),(v1) fe: paddd Pq,Qq | vpaddd Vx,Hx,Wx (66),(v1) -ff: UD0 +ff: EndTable

Table: 3-byte opcode 1 (0x0f 0x38) @@ -717,7 +717,7 @@ AVXcode: 2 7e: vpermt2d/q Vx,Hx,Wx (66),(ev) 7f: vpermt2ps/d Vx,Hx,Wx (66),(ev) 80: INVEPT Gy,Mdq (66) -81: INVVPID Gy,Mdq (66) +81: INVPID Gy,Mdq (66) 82: INVPCID Gy,Mdq (66) 83: vpmultishiftqb Vx,Hx,Wx (66),(ev) 88: vexpandps/d Vpd,Wpd (66),(ev) @@ -970,15 +970,6 @@ GrpTable: Grp9 EndTable

GrpTable: Grp10 -# all are UD1 -0: UD1 -1: UD1 -2: UD1 -3: UD1 -4: UD1 -5: UD1 -6: UD1 -7: UD1 EndTable

# Grp11A and Grp11B are expressed as Grp11 in Intel SDM @@ -1018,7 +1009,7 @@ GrpTable: Grp15 1: fxstor | RDGSBASE Ry (F3),(11B) 2: vldmxcsr Md (v1) | WRFSBASE Ry (F3),(11B) 3: vstmxcsr Md (v1) | WRGSBASE Ry (F3),(11B) -4: XSAVE | ptwrite Ey (F3),(11B) +4: XSAVE 5: XRSTOR | lfence (11B) 6: XSAVEOPT | clwb (66) | mfence (11B) 7: clflush | clflushopt (66) | sfence (11B) diff --git a/tools/objtool/arch/x86/tools/gen-insn-attr-x86.awk b/tools/objtool/arch/x86/tools/gen-insn-attr-x86.awk index b02a36b2c14f..a3d2c62fd805 100644 --- a/tools/objtool/arch/x86/tools/gen-insn-attr-x86.awk +++ b/tools/objtool/arch/x86/tools/gen-insn-attr-x86.awk @@ -1,5 +1,4 @@ #!/bin/awk -f -# SPDX-License-Identifier: GPL-2.0 # gen-insn-attr-x86.awk: Instruction attribute table generator # Written by Masami Hiramatsu mhiramat@redhat.com #