In Documentation/trace/kprobetrace.txt, it says

@SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)

However, the parser doesn't parse minus offset correctly. This fixes the parser to get minus offset correctly.

Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- kernel/trace/trace_kprobe.c | 2 +- kernel/trace/trace_probe.c | 10 +++++----- kernel/trace/trace_probe.h | 2 +- 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 5ce9b8cf7be3..dab4a5b54269 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -754,7 +754,7 @@ static int create_trace_kprobe(int argc, char **argv) /* a symbol specified */ symbol = argv[1]; /* TODO: support .init module functions */ - ret = traceprobe_split_symbol_offset(symbol, &offset); + ret = traceprobe_split_symbol_offset(symbol, (long *)&offset); if (ret) { pr_info("Failed to parse either an address or a symbol.\n"); return ret; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index d59357308677..3e291a754862 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -320,7 +320,7 @@ static fetch_func_t get_fetch_size_function(const struct fetch_type *type, }

/* Split symbol and offset. */ -int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) +int traceprobe_split_symbol_offset(char *symbol, long *offset) { char *tmp; int ret; @@ -328,13 +328,13 @@ int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) if (!offset) return -EINVAL;

- tmp = strchr(symbol, '+'); + tmp = strpbrk(symbol, "+-"); if (tmp) { - /* skip sign because kstrtoul doesn't accept '+' */ - ret = kstrtoul(tmp + 1, 0, offset); + ret = kstrtoul(tmp + 1, 0, (unsigned long *)offset); if (ret) return ret; - + if (*tmp == '-') + *offset = -(*offset); *tmp = '\0'; } else *offset = 0; diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 0745f895f780..75daff22ccea 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -365,7 +365,7 @@ extern int traceprobe_conflict_field_name(const char *name, extern void traceprobe_update_arg(struct probe_arg *arg); extern void traceprobe_free_probe_arg(struct probe_arg *arg);

-extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); +extern int traceprobe_split_symbol_offset(char *symbol, long *offset);

/* Sum up total data length for dynamic arraies (strings) */ static nokprobe_inline int

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Add a testcase for string type with kprobe event. This tests good/bad syntax combinations and also the traced data is correct in several way.

Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- .../ftrace/test.d/kprobe/kprobe_args_string.tc | 46 ++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc

diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc new file mode 100644 index 000000000000..5ba73035e1d9 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc @@ -0,0 +1,46 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Kprobe event string type argument + +[ -f kprobe_events ] || exit_unsupported # this is configurable + +echo 0 > events/enable +echo > kprobe_events + +case `uname -m` in +x86_64) + ARG2=%si + OFFS=8 +;; +i[3456]86) + ARG2=%cx + OFFS=4 +;; +aarch64) + ARG2=%x1 + OFFS=8 +;; +arm*) + ARG2=%r1 + OFFS=4 +;; +*) + echo "Please implement other architecture here" + exit_untested +esac + +: "Test get argument (1)" +echo "p:testprobe create_trace_kprobe arg1=+0(+0(${ARG2})):string" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo test >> kprobe_events +tail -n 1 trace | grep -qe "testprobe.* arg1="test"" + +echo 0 > events/kprobes/testprobe/enable +: "Test get argument (2)" +echo "p:testprobe create_trace_kprobe arg1=+0(+0(${ARG2})):string arg2=+0(+${OFFS}(${ARG2})):string" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo test1 test2 >> kprobe_events +tail -n 1 trace | grep -qe "testprobe.* arg1="test1" arg2="test2"" + +echo 0 > events/enable +echo > kprobe_events

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Cleanup event argument definition code in one place for maintenancability.

Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- kernel/trace/trace_kprobe.c | 32 ++++---------------------------- kernel/trace/trace_probe.c | 21 +++++++++++++++++++++ kernel/trace/trace_probe.h | 2 ++ kernel/trace/trace_uprobe.c | 15 ++------------- 4 files changed, 29 insertions(+), 41 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 59882393fc1b..a96328dfc012 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1146,49 +1146,25 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,

static int kprobe_event_define_fields(struct trace_event_call *event_call) { - int ret, i; + int ret; struct kprobe_trace_entry_head field; struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;

DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); - /* Set argument names as fields */ - for (i = 0; i < tk->tp.nr_args; i++) { - struct probe_arg *parg = &tk->tp.args[i];

- ret = trace_define_field(event_call, parg->type->fmttype, - parg->name, - sizeof(field) + parg->offset, - parg->type->size, - parg->type->is_signed, - FILTER_OTHER); - if (ret) - return ret; - } - return 0; + return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp); }

static int kretprobe_event_define_fields(struct trace_event_call *event_call) { - int ret, i; + int ret; struct kretprobe_trace_entry_head field; struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;

DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); - /* Set argument names as fields */ - for (i = 0; i < tk->tp.nr_args; i++) { - struct probe_arg *parg = &tk->tp.args[i];

- ret = trace_define_field(event_call, parg->type->fmttype, - parg->name, - sizeof(field) + parg->offset, - parg->type->size, - parg->type->is_signed, - FILTER_OTHER); - if (ret) - return ret; - } - return 0; + return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp); }

#ifdef CONFIG_PERF_EVENTS diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 59b0f76fb4a5..4f5447cec44a 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -682,3 +682,24 @@ int set_print_fmt(struct trace_probe *tp, bool is_return)

return 0; } + +int traceprobe_define_arg_fields(struct trace_event_call *event_call, + size_t offset, struct trace_probe *tp) +{ + int ret, i; + + /* Set argument names as fields */ + for (i = 0; i < tp->nr_args; i++) { + struct probe_arg *parg = &tp->args[i]; + + ret = trace_define_field(event_call, parg->type->fmttype, + parg->name, + offset + parg->offset, + parg->type->size, + parg->type->is_signed, + FILTER_OTHER); + if (ret) + return ret; + } + return 0; +} diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 0c8e66f9c855..de928052926b 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -440,3 +440,5 @@ extern struct trace_event_call * create_local_trace_uprobe(char *name, unsigned long offs, bool is_return); extern void destroy_local_trace_uprobe(struct trace_event_call *event_call); #endif +extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, + size_t offset, struct trace_probe *tp); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 4c006a693663..887da2bb63aa 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -982,7 +982,7 @@ probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)

static int uprobe_event_define_fields(struct trace_event_call *event_call) { - int ret, i, size; + int ret, size; struct uprobe_trace_entry_head field; struct trace_uprobe *tu = event_call->data;

@@ -994,19 +994,8 @@ static int uprobe_event_define_fields(struct trace_event_call *event_call) DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); size = SIZEOF_TRACE_ENTRY(false); } - /* Set argument names as fields */ - for (i = 0; i < tu->tp.nr_args; i++) { - struct probe_arg *parg = &tu->tp.args[i]; - - ret = trace_define_field(event_call, parg->type->fmttype, - parg->name, size + parg->offset, - parg->type->size, parg->type->is_signed, - FILTER_OTHER);

- if (ret) - return ret; - } - return 0; + return traceprobe_define_arg_fields(event_call, size, &tu->tp); }

#ifdef CONFIG_PERF_EVENTS

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Replace {k,u}probe event argument fetching framework with switch-case based. Currently that is implemented with structures, macros and chain of function-pointers, which is more complicated than necessary and may get a performance penalty by retpoline.

This simplify that with an array of "fetch_insn" (opcode and oprands), and make process_fetch_insn() just interprets it. No function pointers are used.

Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- Changes in v2: - Allow $comm:string. --- kernel/trace/trace_kprobe.c | 314 +++++++++++----------------- kernel/trace/trace_probe.c | 441 ++++++++++++--------------------------- kernel/trace/trace_probe.h | 232 ++++----------------- kernel/trace/trace_probe_tmpl.h | 120 +++++++++++ kernel/trace/trace_uprobe.c | 150 +++++++------ 5 files changed, 517 insertions(+), 740 deletions(-) create mode 100644 kernel/trace/trace_probe_tmpl.h

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index a96328dfc012..5dd2d470cc7e 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -24,6 +24,7 @@ #include <linux/error-injection.h>

#include "trace_probe.h" +#include "trace_probe_tmpl.h"

#define KPROBE_EVENT_SYSTEM "kprobes" #define KRETPROBE_MAXACTIVE_MAX 4096 @@ -121,184 +122,6 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs);

-/* Memory fetching by symbol */ -struct symbol_cache { - char *symbol; - long offset; - unsigned long addr; -}; - -unsigned long update_symbol_cache(struct symbol_cache *sc) -{ - sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); - - if (sc->addr) - sc->addr += sc->offset; - - return sc->addr; -} - -void free_symbol_cache(struct symbol_cache *sc) -{ - kfree(sc->symbol); - kfree(sc); -} - -struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) -{ - struct symbol_cache *sc; - - if (!sym || strlen(sym) == 0) - return NULL; - - sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); - if (!sc) - return NULL; - - sc->symbol = kstrdup(sym, GFP_KERNEL); - if (!sc->symbol) { - kfree(sc); - return NULL; - } - sc->offset = offset; - update_symbol_cache(sc); - - return sc; -} - -/* - * Kprobes-specific fetch functions - */ -#define DEFINE_FETCH_stack(type) \ -static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ - (unsigned int)((unsigned long)offset)); \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type)); - -DEFINE_BASIC_FETCH_FUNCS(stack) -/* No string on the stack entry */ -#define fetch_stack_string NULL -#define fetch_stack_string_size NULL - -#define DEFINE_FETCH_memory(type) \ -static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ - void *addr, void *dest) \ -{ \ - type retval; \ - if (probe_kernel_address(addr, retval)) \ - *(type *)dest = 0; \ - else \ - *(type *)dest = retval; \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type)); - -DEFINE_BASIC_FETCH_FUNCS(memory) -/* - * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max - * length and relative data location. - */ -static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, - void *addr, void *dest) -{ - int maxlen = get_rloc_len(*(u32 *)dest); - u8 *dst = get_rloc_data(dest); - long ret; - - if (!maxlen) - return; - - /* - * Try to get string again, since the string can be changed while - * probing. - */ - ret = strncpy_from_unsafe(dst, addr, maxlen); - - if (ret < 0) { /* Failed to fetch string */ - dst[0] = '\0'; - *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); - } else { - *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); - } -} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string)); - -/* Return the length of string -- including null terminal byte */ -static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, - void *addr, void *dest) -{ - mm_segment_t old_fs; - int ret, len = 0; - u8 c; - - old_fs = get_fs(); - set_fs(KERNEL_DS); - pagefault_disable(); - - do { - ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); - len++; - } while (c && ret == 0 && len < MAX_STRING_SIZE); - - pagefault_enable(); - set_fs(old_fs); - - if (ret < 0) /* Failed to check the length */ - *(u32 *)dest = 0; - else - *(u32 *)dest = len; -} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size)); - -#define DEFINE_FETCH_symbol(type) \ -void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\ -{ \ - struct symbol_cache *sc = data; \ - if (sc->addr) \ - fetch_memory_##type(regs, (void *)sc->addr, dest); \ - else \ - *(type *)dest = 0; \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type)); - -DEFINE_BASIC_FETCH_FUNCS(symbol) -DEFINE_FETCH_symbol(string) -DEFINE_FETCH_symbol(string_size) - -/* kprobes don't support file_offset fetch methods */ -#define fetch_file_offset_u8 NULL -#define fetch_file_offset_u16 NULL -#define fetch_file_offset_u32 NULL -#define fetch_file_offset_u64 NULL -#define fetch_file_offset_string NULL -#define fetch_file_offset_string_size NULL - -/* Fetch type information table */ -static const struct fetch_type kprobes_fetch_type_table[] = { - /* Special types */ - [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, - sizeof(u32), 1, "__data_loc char[]"), - [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, - string_size, sizeof(u32), 0, "u32"), - /* Basic types */ - ASSIGN_FETCH_TYPE(u8, u8, 0), - ASSIGN_FETCH_TYPE(u16, u16, 0), - ASSIGN_FETCH_TYPE(u32, u32, 0), - ASSIGN_FETCH_TYPE(u64, u64, 0), - ASSIGN_FETCH_TYPE(s8, u8, 1), - ASSIGN_FETCH_TYPE(s16, u16, 1), - ASSIGN_FETCH_TYPE(s32, u32, 1), - ASSIGN_FETCH_TYPE(s64, u64, 1), - ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), - ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), - ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), - ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), - - ASSIGN_FETCH_TYPE_END -}; - /* * Allocate new trace_probe and initialize it (including kprobes). */ @@ -490,14 +313,11 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) /* Internal register function - just handle k*probes and flags */ static int __register_trace_kprobe(struct trace_kprobe *tk) { - int i, ret; + int ret;

if (trace_probe_is_registered(&tk->tp)) return -EINVAL;

- for (i = 0; i < tk->tp.nr_args; i++) - traceprobe_update_arg(&tk->tp.args[i]); - /* Set/clear disabled flag according to tp->flag */ if (trace_probe_is_enabled(&tk->tp)) tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; @@ -830,8 +650,7 @@ static int create_trace_kprobe(int argc, char **argv)

/* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, - is_return, true, - kprobes_fetch_type_table); + is_return, true); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; @@ -985,6 +804,133 @@ static const struct file_operations kprobe_profile_ops = { .release = seq_release, };

+/* Kprobe specific fetch functions */ + +/* Return the length of string -- including null terminal byte */ +static nokprobe_inline void +fetch_store_strlen(unsigned long addr, void *dest) +{ + mm_segment_t old_fs; + int ret, len = 0; + u8 c; + + old_fs = get_fs(); + set_fs(KERNEL_DS); + pagefault_disable(); + + do { + ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); + len++; + } while (c && ret == 0 && len < MAX_STRING_SIZE); + + pagefault_enable(); + set_fs(old_fs); + + if (ret < 0) /* Failed to check the length */ + *(u32 *)dest = 0; + else + *(u32 *)dest = len; +} + +/* + * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max + * length and relative data location. + */ +static nokprobe_inline void +fetch_store_string(unsigned long addr, void *dest) +{ + int maxlen = get_rloc_len(*(u32 *)dest); + u8 *dst = get_rloc_data(dest); + long ret; + + if (!maxlen) + return; + + /* + * Try to get string again, since the string can be changed while + * probing. + */ + ret = strncpy_from_unsafe(dst, (void *)addr, maxlen); + + if (ret < 0) { /* Failed to fetch string */ + dst[0] = '\0'; + *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); + } else { + *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); + } +} + +/* Note that we don't verify it, since the code does not come from user space */ +static int +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, + bool pre) +{ + unsigned long val; + int ret; + + /* 1st stage: get value from context */ + switch (code->op) { + case FETCH_OP_REG: + val = regs_get_register(regs, code->param); + break; + case FETCH_OP_STACK: + val = regs_get_kernel_stack_nth(regs, code->param); + break; + case FETCH_OP_STACKP: + val = kernel_stack_pointer(regs); + break; + case FETCH_OP_RETVAL: + val = regs_return_value(regs); + break; + case FETCH_OP_IMM: + val = code->immediate; + break; + case FETCH_OP_COMM: + val = (unsigned long)current->comm; + break; + default: + return -EILSEQ; + } + code++; + + /* 2nd stage: dereference memory if needed */ + while (code->op == FETCH_OP_DEREF) { + ret = probe_kernel_read(&val, (void *)val + code->offset, + sizeof(val)); + if (ret) + return ret; + code++; + } + + /* 3rd stage: store value to buffer */ + switch (code->op) { + case FETCH_OP_ST_RAW: + fetch_store_raw(val, code, dest); + break; + case FETCH_OP_ST_MEM: + probe_kernel_read(dest, (void *)val + code->offset, code->size); + break; + case FETCH_OP_ST_STRING: + if (pre) + fetch_store_strlen(val + code->offset, dest); + else + fetch_store_string(val + code->offset, dest); + break; + default: + return -EILSEQ; + } + code++; + + /* 4th stage: modify stored value if needed */ + if (code->op == FETCH_OP_MOD_BF) { + fetch_apply_bitfield(code, dest); + code++; + } + + return code->op == FETCH_OP_END ? 0 : -EILSEQ; +} +NOKPROBE_SYMBOL(process_fetch_insn) + /* Kprobe handler */ static nokprobe_inline void __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 37bdd56b4988..cd87490b3492 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -73,176 +73,29 @@ int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)

const char PRINT_TYPE_FMT_NAME(string)[] = "\"%s\"";

-#define CHECK_FETCH_FUNCS(method, fn) \ - (((FETCH_FUNC_NAME(method, u8) == fn) || \ - (FETCH_FUNC_NAME(method, u16) == fn) || \ - (FETCH_FUNC_NAME(method, u32) == fn) || \ - (FETCH_FUNC_NAME(method, u64) == fn) || \ - (FETCH_FUNC_NAME(method, string) == fn) || \ - (FETCH_FUNC_NAME(method, string_size) == fn)) \ - && (fn != NULL)) - -/* Data fetch function templates */ -#define DEFINE_FETCH_reg(type) \ -void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_register(regs, \ - (unsigned int)((unsigned long)offset)); \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type)); -DEFINE_BASIC_FETCH_FUNCS(reg) -/* No string on the register */ -#define fetch_reg_string NULL -#define fetch_reg_string_size NULL - -#define DEFINE_FETCH_retval(type) \ -void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \ - void *dummy, void *dest) \ -{ \ - *(type *)dest = (type)regs_return_value(regs); \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type)); -DEFINE_BASIC_FETCH_FUNCS(retval) -/* No string on the retval */ -#define fetch_retval_string NULL -#define fetch_retval_string_size NULL - -/* Dereference memory access function */ -struct deref_fetch_param { - struct fetch_param orig; - long offset; - fetch_func_t fetch; - fetch_func_t fetch_size; -}; - -#define DEFINE_FETCH_deref(type) \ -void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \ - void *data, void *dest) \ -{ \ - struct deref_fetch_param *dprm = data; \ - unsigned long addr; \ - call_fetch(&dprm->orig, regs, &addr); \ - if (addr) { \ - addr += dprm->offset; \ - dprm->fetch(regs, (void *)addr, dest); \ - } else \ - *(type *)dest = 0; \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type)); -DEFINE_BASIC_FETCH_FUNCS(deref) -DEFINE_FETCH_deref(string) - -void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs, - void *data, void *dest) -{ - struct deref_fetch_param *dprm = data; - unsigned long addr; - - call_fetch(&dprm->orig, regs, &addr); - if (addr && dprm->fetch_size) { - addr += dprm->offset; - dprm->fetch_size(regs, (void *)addr, dest); - } else - *(string_size *)dest = 0; -} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size)); - -static void update_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - update_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - update_symbol_cache(data->orig.data); -} -NOKPROBE_SYMBOL(update_deref_fetch_param); - -static void free_deref_fetch_param(struct deref_fetch_param *data) -{ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - kfree(data); -} -NOKPROBE_SYMBOL(free_deref_fetch_param); - -/* Bitfield fetch function */ -struct bitfield_fetch_param { - struct fetch_param orig; - unsigned char hi_shift; - unsigned char low_shift; +/* Fetch type information table */ +static const struct fetch_type probe_fetch_types[] = { + /* Special types */ + __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, + "__data_loc char[]"), + /* Basic types */ + ASSIGN_FETCH_TYPE(u8, u8, 0), + ASSIGN_FETCH_TYPE(u16, u16, 0), + ASSIGN_FETCH_TYPE(u32, u32, 0), + ASSIGN_FETCH_TYPE(u64, u64, 0), + ASSIGN_FETCH_TYPE(s8, u8, 1), + ASSIGN_FETCH_TYPE(s16, u16, 1), + ASSIGN_FETCH_TYPE(s32, u32, 1), + ASSIGN_FETCH_TYPE(s64, u64, 1), + ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), + ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), + ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), + ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), + + ASSIGN_FETCH_TYPE_END };

-#define DEFINE_FETCH_bitfield(type) \ -void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \ - void *data, void *dest) \ -{ \ - struct bitfield_fetch_param *bprm = data; \ - type buf = 0; \ - call_fetch(&bprm->orig, regs, &buf); \ - if (buf) { \ - buf <<= bprm->hi_shift; \ - buf >>= bprm->low_shift; \ - } \ - *(type *)dest = buf; \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type)); -DEFINE_BASIC_FETCH_FUNCS(bitfield) -#define fetch_bitfield_string NULL -#define fetch_bitfield_string_size NULL - -static void -update_bitfield_fetch_param(struct bitfield_fetch_param *data) -{ - /* - * Don't check the bitfield itself, because this must be the - * last fetch function. - */ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - update_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - update_symbol_cache(data->orig.data); -} - -static void -free_bitfield_fetch_param(struct bitfield_fetch_param *data) -{ - /* - * Don't check the bitfield itself, because this must be the - * last fetch function. - */ - if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) - free_deref_fetch_param(data->orig.data); - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) - free_symbol_cache(data->orig.data); - - kfree(data); -} - -void FETCH_FUNC_NAME(comm, string)(struct pt_regs *regs, - void *data, void *dest) -{ - int maxlen = get_rloc_len(*(u32 *)dest); - u8 *dst = get_rloc_data(dest); - long ret; - - if (!maxlen) - return; - - ret = strlcpy(dst, current->comm, maxlen); - *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); -} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string)); - -void FETCH_FUNC_NAME(comm, string_size)(struct pt_regs *regs, - void *data, void *dest) -{ - *(u32 *)dest = strlen(current->comm) + 1; -} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string_size)); - -static const struct fetch_type *find_fetch_type(const char *type, - const struct fetch_type *ftbl) +static const struct fetch_type *find_fetch_type(const char *type) { int i;

@@ -263,58 +116,27 @@ static const struct fetch_type *find_fetch_type(const char *type,

switch (bs) { case 8: - return find_fetch_type("u8", ftbl); + return find_fetch_type("u8"); case 16: - return find_fetch_type("u16", ftbl); + return find_fetch_type("u16"); case 32: - return find_fetch_type("u32", ftbl); + return find_fetch_type("u32"); case 64: - return find_fetch_type("u64", ftbl); + return find_fetch_type("u64"); default: goto fail; } }

- for (i = 0; ftbl[i].name; i++) { - if (strcmp(type, ftbl[i].name) == 0) - return &ftbl[i]; + for (i = 0; probe_fetch_types[i].name; i++) { + if (strcmp(type, probe_fetch_types[i].name) == 0) + return &probe_fetch_types[i]; }

fail: return NULL; }

-/* Special function : only accept unsigned long */ -static void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest) -{ - *(unsigned long *)dest = kernel_stack_pointer(regs); -} -NOKPROBE_SYMBOL(fetch_kernel_stack_address); - -static void fetch_user_stack_address(struct pt_regs *regs, void *dummy, void *dest) -{ - *(unsigned long *)dest = user_stack_pointer(regs); -} -NOKPROBE_SYMBOL(fetch_user_stack_address); - -static fetch_func_t get_fetch_size_function(const struct fetch_type *type, - fetch_func_t orig_fn, - const struct fetch_type *ftbl) -{ - int i; - - if (type != &ftbl[FETCH_TYPE_STRING]) - return NULL; /* Only string type needs size function */ - - for (i = 0; i < FETCH_MTD_END; i++) - if (type->fetch[i] == orig_fn) - return ftbl[FETCH_TYPE_STRSIZE].fetch[i]; - - WARN_ON(1); /* This should not happen */ - - return NULL; -} - /* Split symbol and offset. */ int traceprobe_split_symbol_offset(char *symbol, long *offset) { @@ -341,7 +163,7 @@ int traceprobe_split_symbol_offset(char *symbol, long *offset) #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))

static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return, + struct fetch_insn *code, bool is_return, bool is_kprobe) { int ret = 0; @@ -349,33 +171,24 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,

if (strcmp(arg, "retval") == 0) { if (is_return) - f->fn = t->fetch[FETCH_MTD_retval]; + code->op = FETCH_OP_RETVAL; else ret = -EINVAL; } else if (strncmp(arg, "stack", 5) == 0) { if (arg[5] == '\0') { - if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR)) - return -EINVAL; - - if (is_kprobe) - f->fn = fetch_kernel_stack_address; - else - f->fn = fetch_user_stack_address; + code->op = FETCH_OP_STACKP; } else if (isdigit(arg[5])) { ret = kstrtoul(arg + 5, 10, &param); if (ret || (is_kprobe && param > PARAM_MAX_STACK)) ret = -EINVAL; else { - f->fn = t->fetch[FETCH_MTD_stack]; - f->data = (void *)param; + code->op = FETCH_OP_STACK; + code->param = (unsigned int)param; } } else ret = -EINVAL; } else if (strcmp(arg, "comm") == 0) { - if (strcmp(t->name, "string") != 0 && - strcmp(t->name, "string_size") != 0) - return -EINVAL; - f->fn = t->fetch[FETCH_MTD_comm]; + code->op = FETCH_OP_COMM; } else ret = -EINVAL;

@@ -383,10 +196,12 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, }

/* Recursive argument parser */ -static int parse_probe_arg(char *arg, const struct fetch_type *t, - struct fetch_param *f, bool is_return, bool is_kprobe, - const struct fetch_type *ftbl) +static int +parse_probe_arg(char *arg, const struct fetch_type *type, + struct fetch_insn **pcode, struct fetch_insn *end, + bool is_return, bool is_kprobe) { + struct fetch_insn *code = *pcode; unsigned long param; long offset; char *tmp; @@ -394,14 +209,15 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,

switch (arg[0]) { case '$': - ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe); + ret = parse_probe_vars(arg + 1, type, code, + is_return, is_kprobe); break;

case '%': /* named register */ ret = regs_query_register_offset(arg + 1); if (ret >= 0) { - f->fn = t->fetch[FETCH_MTD_reg]; - f->data = (void *)(unsigned long)ret; + code->op = FETCH_OP_REG; + code->param = (unsigned int)ret; ret = 0; } break; @@ -411,9 +227,9 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, ret = kstrtoul(arg + 1, 0, &param); if (ret) break; - - f->fn = t->fetch[FETCH_MTD_memory]; - f->data = (void *)param; + /* load address */ + code->op = FETCH_OP_IMM; + code->immediate = param; } else if (arg[1] == '+') { /* kprobes don't support file offsets */ if (is_kprobe) @@ -423,8 +239,8 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, if (ret) break;

- f->fn = t->fetch[FETCH_MTD_file_offset]; - f->data = (void *)offset; + code->op = FETCH_OP_FOFFS; + code->immediate = (unsigned long)offset; // imm64? } else { /* uprobes don't support symbols */ if (!is_kprobe) @@ -434,10 +250,19 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, if (ret) break;

- f->data = alloc_symbol_cache(arg + 1, offset); - if (f->data) - f->fn = t->fetch[FETCH_MTD_symbol]; + code->op = FETCH_OP_IMM; + code->immediate = + (unsigned long)kallsyms_lookup_name(arg + 1); + if (!code->immediate) + return -ENOENT; + code->immediate += offset; } + /* These are fetching from memory */ + if (++code == end) + return -E2BIG; + *pcode = code; + code->op = FETCH_OP_DEREF; + code->offset = offset; break;

case '+': /* deref memory */ @@ -445,11 +270,10 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, case '-': tmp = strchr(arg, '('); if (!tmp) - break; + return -EINVAL;

*tmp = '\0'; ret = kstrtol(arg, 0, &offset); - if (ret) break;

@@ -457,36 +281,28 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, tmp = strrchr(arg, ')');

if (tmp) { - struct deref_fetch_param *dprm; - const struct fetch_type *t2; + const struct fetch_type *t2 = find_fetch_type(NULL);

- t2 = find_fetch_type(NULL, ftbl); *tmp = '\0'; - dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL); - - if (!dprm) - return -ENOMEM; - - dprm->offset = offset; - dprm->fetch = t->fetch[FETCH_MTD_memory]; - dprm->fetch_size = get_fetch_size_function(t, - dprm->fetch, ftbl); - ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, - is_kprobe, ftbl); + ret = parse_probe_arg(arg, t2, &code, end, is_return, + is_kprobe); if (ret) - kfree(dprm); - else { - f->fn = t->fetch[FETCH_MTD_deref]; - f->data = (void *)dprm; - } + break; + if (code->op == FETCH_OP_COMM) + return -EINVAL; + if (++code == end) + return -E2BIG; + *pcode = code; + + code->op = FETCH_OP_DEREF; + code->offset = offset; } break; } - if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ - pr_info("%s type has no corresponding fetch method.\n", t->name); + if (!ret && code->op == FETCH_OP_NOP) { + /* Parsed, but do not find fetch method */ ret = -EINVAL; } - return ret; }

@@ -495,22 +311,15 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, /* Bitfield type needs to be parsed into a fetch function */ static int __parse_bitfield_probe_arg(const char *bf, const struct fetch_type *t, - struct fetch_param *f) + struct fetch_insn **pcode) { - struct bitfield_fetch_param *bprm; + struct fetch_insn *code = *pcode; unsigned long bw, bo; char *tail;

if (*bf != 'b') return 0;

- bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); - if (!bprm) - return -ENOMEM; - - bprm->orig = *f; - f->fn = t->fetch[FETCH_MTD_bitfield]; - f->data = (void *)bprm; bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */

if (bw == 0 || *tail != '@') @@ -521,18 +330,24 @@ static int __parse_bitfield_probe_arg(const char *bf,

if (tail == bf || *tail != '/') return -EINVAL; + code++; + if (code->op != FETCH_OP_NOP) + return -E2BIG; + *pcode = code;

- bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); - bprm->low_shift = bprm->hi_shift + bo; + code->op = FETCH_OP_MOD_BF; + code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); + code->rshift = BYTES_TO_BITS(t->size) - bw; + code->basesize = t->size;

return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; }

/* String length checking wrapper */ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return, bool is_kprobe, - const struct fetch_type *ftbl) + struct probe_arg *parg, bool is_return, bool is_kprobe) { + struct fetch_insn *code, *tmp = NULL; const char *t; int ret;

@@ -556,25 +371,67 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, */ if (!t && strcmp(arg, "$comm") == 0) t = "string"; - parg->type = find_fetch_type(t, ftbl); + parg->type = find_fetch_type(t); if (!parg->type) { pr_info("Unsupported type: %s\n", t); return -EINVAL; } parg->offset = *size; *size += parg->type->size; - ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, - is_kprobe, ftbl); - - if (ret >= 0 && t != NULL) - ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);

- if (ret >= 0) { - parg->fetch_size.fn = get_fetch_size_function(parg->type, - parg->fetch.fn, - ftbl); - parg->fetch_size.data = parg->fetch.data; + code = tmp = kzalloc(sizeof(*code) * FETCH_INSN_MAX, GFP_KERNEL); + if (!code) + return -ENOMEM; + code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; + + ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], + is_return, is_kprobe); + if (ret) + goto fail; + + /* Store operation */ + if (!strcmp(parg->type->name, "string")) { + if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM && + code->op != FETCH_OP_COMM) { + pr_info("string only accepts memory or address.\n"); + ret = -EINVAL; + goto fail; + } + /* Since IMM or COMM must be the 1st insn, this is safe */ + if (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM) + code++; + code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */ + parg->dynamic = true; + } else if (code->op == FETCH_OP_DEREF) { + code->op = FETCH_OP_ST_MEM; + code->size = parg->type->size; + } else { + code++; + if (code->op != FETCH_OP_NOP) { + ret = -E2BIG; + goto fail; + } + code->op = FETCH_OP_ST_RAW; + code->size = parg->type->size; } + /* Modify operation */ + if (t != NULL) { + ret = __parse_bitfield_probe_arg(t, parg->type, &code); + if (ret) + goto fail; + } + code++; + code->op = FETCH_OP_END; + + /* Shrink down the code buffer */ + parg->code = kzalloc(sizeof(*code) * (code - tmp + 1), GFP_KERNEL); + if (!parg->code) + ret = -ENOMEM; + else + memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); + +fail: + kfree(tmp);

return ret; } @@ -596,25 +453,9 @@ int traceprobe_conflict_field_name(const char *name, return 0; }

-void traceprobe_update_arg(struct probe_arg *arg) -{ - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) - update_bitfield_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) - update_deref_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) - update_symbol_cache(arg->fetch.data); -} - void traceprobe_free_probe_arg(struct probe_arg *arg) { - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) - free_bitfield_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) - free_deref_fetch_param(arg->fetch.data); - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) - free_symbol_cache(arg->fetch.data); - + kfree(arg->code); kfree(arg->name); kfree(arg->comm); } diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index de928052926b..89d853ef5174 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -91,25 +91,50 @@ static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) return (u8 *)ent + get_rloc_offs(*dl); }

-/* Data fetch function type */ -typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); /* Printing function type */ typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);

-/* Fetch types */ -enum { - FETCH_MTD_reg = 0, - FETCH_MTD_stack, - FETCH_MTD_retval, - FETCH_MTD_comm, - FETCH_MTD_memory, - FETCH_MTD_symbol, - FETCH_MTD_deref, - FETCH_MTD_bitfield, - FETCH_MTD_file_offset, - FETCH_MTD_END, +enum fetch_op { + FETCH_OP_NOP = 0, + // Stage 1 (load) ops + FETCH_OP_REG, /* Register : .param = offset */ + FETCH_OP_STACK, /* Stack : .param = index */ + FETCH_OP_STACKP, /* Stack pointer */ + FETCH_OP_RETVAL, /* Return value */ + FETCH_OP_IMM, /* Immediate : .immediate */ + FETCH_OP_COMM, /* Current comm */ + FETCH_OP_FOFFS, /* File offset: .immediate */ + // Stage 2 (dereference) op + FETCH_OP_DEREF, /* Dereference: .offset */ + // Stage 3 (store) ops + FETCH_OP_ST_RAW, /* Raw: .size */ + FETCH_OP_ST_MEM, /* Mem: .offset, .size */ + FETCH_OP_ST_STRING, /* String: .offset, .size */ + // Stage 4 (modify) op + FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */ + FETCH_OP_END, };

+struct fetch_insn { + enum fetch_op op; + union { + unsigned int param; + struct { + unsigned int size; + int offset; + }; + struct { + unsigned char basesize; + unsigned char lshift; + unsigned char rshift; + }; + unsigned long immediate; + }; +}; + +/* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */ +#define FETCH_INSN_MAX 16 + /* Fetch type information table */ struct fetch_type { const char *name; /* Name of type */ @@ -118,13 +143,6 @@ struct fetch_type { print_type_func_t print; /* Print functions */ const char *fmt; /* Fromat string */ const char *fmttype; /* Name in format file */ - /* Fetch functions */ - fetch_func_t fetch[FETCH_MTD_END]; -}; - -struct fetch_param { - fetch_func_t fn; - void *data; };

/* For defining macros, define string/string_size types */ @@ -154,66 +172,12 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(x64);

DECLARE_BASIC_PRINT_TYPE_FUNC(string);

-#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type - -/* Declare macro for basic types */ -#define DECLARE_FETCH_FUNC(method, type) \ -extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, \ - void *data, void *dest) - -#define DECLARE_BASIC_FETCH_FUNCS(method) \ -DECLARE_FETCH_FUNC(method, u8); \ -DECLARE_FETCH_FUNC(method, u16); \ -DECLARE_FETCH_FUNC(method, u32); \ -DECLARE_FETCH_FUNC(method, u64) - -DECLARE_BASIC_FETCH_FUNCS(reg); -#define fetch_reg_string NULL -#define fetch_reg_string_size NULL - -DECLARE_BASIC_FETCH_FUNCS(retval); -#define fetch_retval_string NULL -#define fetch_retval_string_size NULL - -DECLARE_BASIC_FETCH_FUNCS(symbol); -DECLARE_FETCH_FUNC(symbol, string); -DECLARE_FETCH_FUNC(symbol, string_size); - -DECLARE_BASIC_FETCH_FUNCS(deref); -DECLARE_FETCH_FUNC(deref, string); -DECLARE_FETCH_FUNC(deref, string_size); - -DECLARE_BASIC_FETCH_FUNCS(bitfield); -#define fetch_bitfield_string NULL -#define fetch_bitfield_string_size NULL - -/* comm only makes sense as a string */ -#define fetch_comm_u8 NULL -#define fetch_comm_u16 NULL -#define fetch_comm_u32 NULL -#define fetch_comm_u64 NULL -DECLARE_FETCH_FUNC(comm, string); -DECLARE_FETCH_FUNC(comm, string_size); - -/* - * Define macro for basic types - we don't need to define s* types, because - * we have to care only about bitwidth at recording time. - */ -#define DEFINE_BASIC_FETCH_FUNCS(method) \ -DEFINE_FETCH_##method(u8) \ -DEFINE_FETCH_##method(u16) \ -DEFINE_FETCH_##method(u32) \ -DEFINE_FETCH_##method(u64) - /* Default (unsigned long) fetch type */ #define __DEFAULT_FETCH_TYPE(t) x##t #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)

-#define ASSIGN_FETCH_FUNC(method, type) \ - [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) - #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ {.name = _name, \ .size = _size, \ @@ -221,17 +185,6 @@ DEFINE_FETCH_##method(u64) .print = PRINT_TYPE_FUNC_NAME(ptype), \ .fmt = PRINT_TYPE_FMT_NAME(ptype), \ .fmttype = _fmttype, \ - .fetch = { \ -ASSIGN_FETCH_FUNC(reg, ftype), \ -ASSIGN_FETCH_FUNC(stack, ftype), \ -ASSIGN_FETCH_FUNC(retval, ftype), \ -ASSIGN_FETCH_FUNC(comm, ftype), \ -ASSIGN_FETCH_FUNC(memory, ftype), \ -ASSIGN_FETCH_FUNC(symbol, ftype), \ -ASSIGN_FETCH_FUNC(deref, ftype), \ -ASSIGN_FETCH_FUNC(bitfield, ftype), \ -ASSIGN_FETCH_FUNC(file_offset, ftype), \ - } \ }

#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ @@ -243,42 +196,10 @@ ASSIGN_FETCH_FUNC(file_offset, ftype), \

#define ASSIGN_FETCH_TYPE_END {}

-#define FETCH_TYPE_STRING 0 -#define FETCH_TYPE_STRSIZE 1 - #ifdef CONFIG_KPROBE_EVENTS -struct symbol_cache; -unsigned long update_symbol_cache(struct symbol_cache *sc); -void free_symbol_cache(struct symbol_cache *sc); -struct symbol_cache *alloc_symbol_cache(const char *sym, long offset); bool trace_kprobe_on_func_entry(struct trace_event_call *call); bool trace_kprobe_error_injectable(struct trace_event_call *call); #else -/* uprobes do not support symbol fetch methods */ -#define fetch_symbol_u8 NULL -#define fetch_symbol_u16 NULL -#define fetch_symbol_u32 NULL -#define fetch_symbol_u64 NULL -#define fetch_symbol_string NULL -#define fetch_symbol_string_size NULL - -struct symbol_cache { -}; -static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc) -{ - return 0; -} - -static inline void __used free_symbol_cache(struct symbol_cache *sc) -{ -} - -static inline struct symbol_cache * __used -alloc_symbol_cache(const char *sym, long offset) -{ - return NULL; -} - static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call) { return false; @@ -291,8 +212,8 @@ static inline bool trace_kprobe_error_injectable(struct trace_event_call *call) #endif /* CONFIG_KPROBE_EVENTS */

struct probe_arg { - struct fetch_param fetch; - struct fetch_param fetch_size; + struct fetch_insn *code; + bool dynamic;/* Dynamic array (string) is used */ unsigned int offset; /* Offset from argument entry */ const char *name; /* Name of this argument */ const char *comm; /* Command of this argument */ @@ -324,12 +245,6 @@ static inline bool trace_probe_is_registered(struct trace_probe *tp) return !!(tp->flags & TP_FLAG_REGISTERED); }

-static nokprobe_inline void call_fetch(struct fetch_param *fprm, - struct pt_regs *regs, void *dest) -{ - return fprm->fn(regs, fprm->data, dest); -} - /* Check the name is good for event/group/fields */ static inline bool is_good_name(const char *name) { @@ -355,8 +270,7 @@ find_event_file_link(struct trace_probe *tp, struct trace_event_file *file) }

extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return, bool is_kprobe, - const struct fetch_type *ftbl); + struct probe_arg *parg, bool is_return, bool is_kprobe);

extern int traceprobe_conflict_field_name(const char *name, struct probe_arg *args, int narg); @@ -366,68 +280,6 @@ extern void traceprobe_free_probe_arg(struct probe_arg *arg);

extern int traceprobe_split_symbol_offset(char *symbol, long *offset);

-/* Sum up total data length for dynamic arraies (strings) */ -static nokprobe_inline int -__get_data_size(struct trace_probe *tp, struct pt_regs *regs) -{ - int i, ret = 0; - u32 len; - - for (i = 0; i < tp->nr_args; i++) - if (unlikely(tp->args[i].fetch_size.fn)) { - call_fetch(&tp->args[i].fetch_size, regs, &len); - ret += len; - } - - return ret; -} - -/* Store the value of each argument */ -static nokprobe_inline void -store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, - u8 *data, int maxlen) -{ - int i; - u32 end = tp->size; - u32 *dl; /* Data (relative) location */ - - for (i = 0; i < tp->nr_args; i++) { - if (unlikely(tp->args[i].fetch_size.fn)) { - /* - * First, we set the relative location and - * maximum data length to *dl - */ - dl = (u32 *)(data + tp->args[i].offset); - *dl = make_data_rloc(maxlen, end - tp->args[i].offset); - /* Then try to fetch string or dynamic array data */ - call_fetch(&tp->args[i].fetch, regs, dl); - /* Reduce maximum length */ - end += get_rloc_len(*dl); - maxlen -= get_rloc_len(*dl); - /* Trick here, convert data_rloc to data_loc */ - *dl = convert_rloc_to_loc(*dl, - ent_size + tp->args[i].offset); - } else - /* Just fetching data normally */ - call_fetch(&tp->args[i].fetch, regs, - data + tp->args[i].offset); - } -} - -static inline int -print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args, - u8 *data, void *field) -{ - int i; - - for (i = 0; i < nr_args; i++) { - trace_seq_printf(s, " %s=", args[i].name); - if (!args[i].type->print(s, data + args[i].offset, field)) - return -ENOMEM; - } - return 0; -} - extern int set_print_fmt(struct trace_probe *tp, bool is_return);

#ifdef CONFIG_PERF_EVENTS diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h new file mode 100644 index 000000000000..c8a5272abf01 --- /dev/null +++ b/kernel/trace/trace_probe_tmpl.h @@ -0,0 +1,120 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Traceprobe fetch helper inlines + */ + +static nokprobe_inline void +fetch_store_raw(unsigned long val, struct fetch_insn *code, void *buf) +{ + switch (code->size) { + case 1: + *(u8 *)buf = (u8)val; + break; + case 2: + *(u16 *)buf = (u16)val; + break; + case 4: + *(u32 *)buf = (u32)val; + break; + case 8: + //TBD: 32bit signed + *(u64 *)buf = (u64)val; + break; + default: + *(unsigned long *)buf = val; + } +} + +static nokprobe_inline void +fetch_apply_bitfield(struct fetch_insn *code, void *buf) +{ + switch (code->basesize) { + case 1: + *(u8 *)buf <<= code->lshift; + *(u8 *)buf >>= code->rshift; + break; + case 2: + *(u16 *)buf <<= code->lshift; + *(u16 *)buf >>= code->rshift; + break; + case 4: + *(u32 *)buf <<= code->lshift; + *(u32 *)buf >>= code->rshift; + break; + case 8: + *(u64 *)buf <<= code->lshift; + *(u64 *)buf >>= code->rshift; + break; + } +} + +/* Define this for each callsite */ +static int +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, + void *dest, bool pre); + +/* Sum up total data length for dynamic arraies (strings) */ +static nokprobe_inline int +__get_data_size(struct trace_probe *tp, struct pt_regs *regs) +{ + struct probe_arg *arg; + int i, ret = 0; + u32 len; + + for (i = 0; i < tp->nr_args; i++) { + arg = tp->args + i; + if (unlikely(arg->dynamic)) { + process_fetch_insn(arg->code, regs, &len, true); + ret += len; + } + } + + return ret; +} + +/* Store the value of each argument */ +static nokprobe_inline void +store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, + u8 *data, int maxlen) +{ + struct probe_arg *arg; + u32 end = tp->size; + u32 *dl; /* Data (relative) location */ + int i; + + for (i = 0; i < tp->nr_args; i++) { + arg = tp->args + i; + if (unlikely(arg->dynamic)) { + /* + * First, we set the relative location and + * maximum data length to *dl + */ + dl = (u32 *)(data + arg->offset); + *dl = make_data_rloc(maxlen, end - arg->offset); + /* Then try to fetch string or dynamic array data */ + process_fetch_insn(arg->code, regs, dl, false); + /* Reduce maximum length */ + end += get_rloc_len(*dl); + maxlen -= get_rloc_len(*dl); + /* Trick here, convert data_rloc to data_loc */ + *dl = convert_rloc_to_loc(*dl, ent_size + arg->offset); + } else + /* Just fetching data normally */ + process_fetch_insn(arg->code, regs, data + arg->offset, + false); + } +} + +static inline int +print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args, + u8 *data, void *field) +{ + int i; + + for (i = 0; i < nr_args; i++) { + trace_seq_printf(s, " %s=", args[i].name); + if (!args[i].type->print(s, data + args[i].offset, field)) + return -ENOMEM; + } + return 0; +} diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 887da2bb63aa..9fc0123c721f 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -27,6 +27,7 @@ #include <linux/rculist.h>

#include "trace_probe.h" +#include "trace_probe_tmpl.h"

#define UPROBE_EVENT_SYSTEM "uprobes"

@@ -109,37 +110,19 @@ static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) /* * Uprobes-specific fetch functions */ -#define DEFINE_FETCH_stack(type) \ -static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)get_user_stack_nth(regs, \ - ((unsigned long)offset)); \ -} -DEFINE_BASIC_FETCH_FUNCS(stack) -/* No string on the stack entry */ -#define fetch_stack_string NULL -#define fetch_stack_string_size NULL - -#define DEFINE_FETCH_memory(type) \ -static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ - void *addr, void *dest) \ -{ \ - type retval; \ - void __user *vaddr = (void __force __user *) addr; \ - \ - if (copy_from_user(&retval, vaddr, sizeof(type))) \ - *(type *)dest = 0; \ - else \ - *(type *) dest = retval; \ +static nokprobe_inline int +probe_user_read(void *dest, void *src, size_t size) +{ + void __user *vaddr = (void __force __user *)src; + + return copy_from_user(dest, vaddr, size); } -DEFINE_BASIC_FETCH_FUNCS(memory) /* * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max * length and relative data location. */ -static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, - void *addr, void *dest) +static nokprobe_inline void +fetch_store_string(unsigned long addr, void *dest) { long ret; u32 rloc = *(u32 *)dest; @@ -160,8 +143,9 @@ static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, } }

-static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, - void *addr, void *dest) +/* Return the length of string -- including null terminal byte */ +static nokprobe_inline void +fetch_store_strlen(unsigned long addr, void *dest) { int len; void __user *vaddr = (void __force __user *) addr; @@ -174,7 +158,7 @@ static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, *(u32 *)dest = len; }

-static unsigned long translate_user_vaddr(void *file_offset) +static unsigned long translate_user_vaddr(unsigned long file_offset) { unsigned long base_addr; struct uprobe_dispatch_data *udd; @@ -182,44 +166,79 @@ static unsigned long translate_user_vaddr(void *file_offset) udd = (void *) current->utask->vaddr;

base_addr = udd->bp_addr - udd->tu->offset; - return base_addr + (unsigned long)file_offset; + return base_addr + file_offset; }

-#define DEFINE_FETCH_file_offset(type) \ -static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \ - void *offset, void *dest)\ -{ \ - void *vaddr = (void *)translate_user_vaddr(offset); \ - \ - FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \ +/* Note that we don't verify it, since the code does not come from user space */ +static int +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, + bool pre) +{ + unsigned long val; + int ret; + + /* 1st stage: get value from context */ + switch (code->op) { + case FETCH_OP_REG: + val = regs_get_register(regs, code->param); + break; + case FETCH_OP_STACK: + val = get_user_stack_nth(regs, code->param); + break; + case FETCH_OP_STACKP: + val = user_stack_pointer(regs); + break; + case FETCH_OP_RETVAL: + val = regs_return_value(regs); + break; + case FETCH_OP_IMM: + val = code->immediate; + break; + case FETCH_OP_FOFFS: + val = translate_user_vaddr(code->immediate); + break; + default: + return -EILSEQ; + } + code++; + + /* 2nd stage: dereference memory if needed */ + while (code->op == FETCH_OP_DEREF) { + ret = probe_user_read(&val, (void *)val + code->offset, + sizeof(val)); + if (ret) + return ret; + code++; + } + + /* 3rd stage: store value to buffer */ + switch (code->op) { + case FETCH_OP_ST_RAW: + fetch_store_raw(val, code, dest); + break; + case FETCH_OP_ST_MEM: + probe_user_read(dest, (void *)val + code->offset, code->size); + break; + case FETCH_OP_ST_STRING: + if (pre) + fetch_store_strlen(val + code->offset, dest); + else + fetch_store_string(val + code->offset, dest); + break; + default: + return -EILSEQ; + } + code++; + + /* 4th stage: modify stored value if needed */ + if (code->op == FETCH_OP_MOD_BF) { + fetch_apply_bitfield(code, dest); + code++; + } + + return code->op == FETCH_OP_END ? 0 : -EILSEQ; } -DEFINE_BASIC_FETCH_FUNCS(file_offset) -DEFINE_FETCH_file_offset(string) -DEFINE_FETCH_file_offset(string_size) - -/* Fetch type information table */ -static const struct fetch_type uprobes_fetch_type_table[] = { - /* Special types */ - [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, - sizeof(u32), 1, "__data_loc char[]"), - [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, - string_size, sizeof(u32), 0, "u32"), - /* Basic types */ - ASSIGN_FETCH_TYPE(u8, u8, 0), - ASSIGN_FETCH_TYPE(u16, u16, 0), - ASSIGN_FETCH_TYPE(u32, u32, 0), - ASSIGN_FETCH_TYPE(u64, u64, 0), - ASSIGN_FETCH_TYPE(s8, u8, 1), - ASSIGN_FETCH_TYPE(s16, u16, 1), - ASSIGN_FETCH_TYPE(s32, u32, 1), - ASSIGN_FETCH_TYPE(s64, u64, 1), - ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), - ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), - ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), - ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), - - ASSIGN_FETCH_TYPE_END -}; +NOKPROBE_SYMBOL(process_fetch_insn)

static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) { @@ -538,8 +557,7 @@ static int create_trace_uprobe(int argc, char **argv)

/* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg, - is_return, false, - uprobes_fetch_type_table); + is_return, false); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error;

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Append traceprobe_ for exported function set_print_fmt() as same as other functions.

Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- kernel/trace/trace_kprobe.c | 4 ++-- kernel/trace/trace_probe.c | 2 +- kernel/trace/trace_probe.h | 2 +- kernel/trace/trace_uprobe.c | 4 ++-- 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index ee41d5700e25..ec20f0b56cfe 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1305,7 +1305,7 @@ static int register_kprobe_event(struct trace_kprobe *tk)

init_trace_event_call(tk, call);

- if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) + if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) return -ENOMEM; ret = register_trace_event(&call->event); if (!ret) { @@ -1362,7 +1362,7 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,

init_trace_event_call(tk, &tk->tp.call);

- if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { + if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { ret = -ENOMEM; goto error; } diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index cd87490b3492..8d43f377143d 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -504,7 +504,7 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, return pos; }

-int set_print_fmt(struct trace_probe *tp, bool is_return) +int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return) { int len; char *print_fmt; diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index d1b8bd74bf56..3bc43c1ce628 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -266,7 +266,7 @@ extern void traceprobe_free_probe_arg(struct probe_arg *arg);

extern int traceprobe_split_symbol_offset(char *symbol, long *offset);

-extern int set_print_fmt(struct trace_probe *tp, bool is_return); +extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);

#ifdef CONFIG_PERF_EVENTS extern struct trace_event_call * diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index de4f91bb313a..fafd48310823 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1314,7 +1314,7 @@ static int register_uprobe_event(struct trace_uprobe *tu)

init_trace_event_call(tu, call);

- if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) + if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) return -ENOMEM;

ret = register_trace_event(&call->event); @@ -1388,7 +1388,7 @@ create_local_trace_uprobe(char *name, unsigned long offs, bool is_return) tu->filename = kstrdup(name, GFP_KERNEL); init_trace_event_call(tu, &tu->tp.call);

- if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) { + if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) { ret = -ENOMEM; goto error; }

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Add "symbol" type to probeevent, which is an alias of u32 or u64 (depends on BITS_PER_LONG). This shows the result value in symbol+offset style. This type is only available with kprobe events.

Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- Changes in v2: - Add symbol type to README file. --- Documentation/trace/kprobetrace.txt | 3 +++ kernel/trace/trace.c | 2 +- kernel/trace/trace_probe.c | 8 ++++++++ kernel/trace/trace_probe.h | 12 +++++++++--- 4 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index 1a3a3d6bc2a8..d49381f2e411 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -62,6 +62,7 @@ respectively. 'x' prefix implies it is unsigned. Traced arguments are shown in decimal ('s' and 'u') or hexadecimal ('x'). Without type casting, 'x32' or 'x64' is used depends on the architecture (e.g. x86-32 uses x32, and x86-64 uses x64). + String type is a special type, which fetches a "null-terminated" string from kernel space. This means it will fail and store NULL if the string container has been paged out. @@ -70,6 +71,8 @@ offset, and container-size (usually 32). The syntax is;

b<bit-width>@<bit-offset>/<container-size>

+Symbol type('symbol') is an alias of u32 or u64 type (depends on BITS_PER_LONG) +which shows given pointer in "symbol+offset" style. For $comm, the default type is "string"; any other type is invalid.

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 20a2300ae4e8..8f08811d15b8 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4609,7 +4609,7 @@ static const char readme_msg[] = "\t args: <name>=fetcharg[:type]\n" "\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n" "\t $stack<index>, $stack, $retval, $comm\n" - "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string,\n" + "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" "\t b<bit-width>@<bit-offset>/<container-size>\n" #endif " events/\t\t- Directory containing all trace event subsystems:\n" diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 8d43f377143d..f41a2989130c 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -58,6 +58,13 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")

+int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) +{ + trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data); + return !trace_seq_has_overflowed(s); +} +const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS"; + /* Print type function for string type */ int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) { @@ -91,6 +98,7 @@ static const struct fetch_type probe_fetch_types[] = { ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), + ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),

ASSIGN_FETCH_TYPE_END }; diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 3bc43c1ce628..ef477bd8468a 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -157,6 +157,7 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(x32); DECLARE_BASIC_PRINT_TYPE_FUNC(x64);

DECLARE_BASIC_PRINT_TYPE_FUNC(string); +DECLARE_BASIC_PRINT_TYPE_FUNC(symbol);

/* Default (unsigned long) fetch type */ #define __DEFAULT_FETCH_TYPE(t) x##t @@ -164,6 +165,10 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(string); #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)

+#define __ADDR_FETCH_TYPE(t) u##t +#define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t) +#define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG) + #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ {.name = _name, \ .size = _size, \ @@ -172,13 +177,14 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(string); .fmt = PRINT_TYPE_FMT_NAME(ptype), \ .fmttype = _fmttype, \ } - +#define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ + __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype) #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ - __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) + _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype)

/* If ptype is an alias of atype, use this macro (show atype in format) */ #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \ - __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #atype) + _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)

#define ASSIGN_FETCH_TYPE_END {}

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Add $argN special fetch variable for accessing function arguments. This allows user to trace the Nth argument easily at the function entry.

Note that this returns most probably assignment of registers and stacks. In some case, it may not work well. If you need to access correct registers or stacks you should use perf-probe.

Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- Changes in v2: - Add $argN in README file - Make N start from 1 as same as auto-generate event argument names. --- Documentation/trace/kprobetrace.txt | 10 ++++++---- kernel/trace/trace.c | 2 +- kernel/trace/trace_kprobe.c | 18 +++++++++++++----- kernel/trace/trace_probe.c | 36 ++++++++++++++++++++++------------- kernel/trace/trace_probe.h | 9 ++++++++- kernel/trace/trace_uprobe.c | 2 +- 6 files changed, 52 insertions(+), 25 deletions(-)

diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index d49381f2e411..1d082f8ffeee 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -43,16 +43,18 @@ Synopsis of kprobe_events @SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol) $stackN : Fetch Nth entry of stack (N >= 0) $stack : Fetch stack address. - $retval : Fetch return value.(*) + $argN : Fetch the Nth function argument. (N >= 1) (*1) + $retval : Fetch return value.(*2) $comm : Fetch current task comm. - +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**) + +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(*3) NAME=FETCHARG : Set NAME as the argument name of FETCHARG. FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types (u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types (x8/x16/x32/x64), "string" and bitfield are supported.

- (*) only for return probe. - (**) this is useful for fetching a field of data structures. + (*1) only for the probe on function entry (offs == 0). + (*2) only for return probe. + (*3) this is useful for fetching a field of data structures.

Types ----- diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8f08811d15b8..94423529b986 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4608,7 +4608,7 @@ static const char readme_msg[] = #endif "\t args: <name>=fetcharg[:type]\n" "\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n" - "\t $stack<index>, $stack, $retval, $comm\n" + "\t $stack<index>, $stack, $retval, $comm, $arg<N>\n" "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" "\t b<bit-width>@<bit-offset>/<container-size>\n" #endif diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 5025907e0c99..df39c7d5dd4c 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -490,13 +490,15 @@ static int create_trace_kprobe(int argc, char **argv) unsigned long offset = 0; void *addr = NULL; char buf[MAX_EVENT_NAME_LEN]; + unsigned int flags = TPARG_FL_KERNEL;

/* argc must be >= 1 */ if (argv[0][0] == 'p') is_return = false; - else if (argv[0][0] == 'r') + else if (argv[0][0] == 'r') { is_return = true; - else if (argv[0][0] == '-') + flags |= TPARG_FL_RETURN; + } else if (argv[0][0] == '-') is_delete = true; else { pr_info("Probe definition must be started with 'p', 'r' or" @@ -579,8 +581,9 @@ static int create_trace_kprobe(int argc, char **argv) pr_info("Failed to parse either an address or a symbol.\n"); return ret; } - if (offset && is_return && - !kprobe_on_func_entry(NULL, symbol, offset)) { + if (kprobe_on_func_entry(NULL, symbol, offset)) + flags |= TPARG_FL_FENTRY; + if (offset && is_return && !(flags & TPARG_FL_FENTRY)) { pr_info("Given offset is not valid for return probe.\n"); return -EINVAL; } @@ -650,7 +653,7 @@ static int create_trace_kprobe(int argc, char **argv)

/* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, - is_return, true); + flags); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; @@ -890,6 +893,11 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, case FETCH_OP_COMM: val = (unsigned long)current->comm; break; +#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API + case FETCH_OP_ARG: + val = regs_get_kernel_argument(regs, code->param); + break; +#endif default: return -EILSEQ; } diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index f41a2989130c..f4b83927d6c0 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -171,14 +171,13 @@ int traceprobe_split_symbol_offset(char *symbol, long *offset) #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))

static int parse_probe_vars(char *arg, const struct fetch_type *t, - struct fetch_insn *code, bool is_return, - bool is_kprobe) + struct fetch_insn *code, unsigned int flags) { int ret = 0; unsigned long param;

if (strcmp(arg, "retval") == 0) { - if (is_return) + if (flags & TPARG_FL_RETURN) code->op = FETCH_OP_RETVAL; else ret = -EINVAL; @@ -187,7 +186,8 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, code->op = FETCH_OP_STACKP; } else if (isdigit(arg[5])) { ret = kstrtoul(arg + 5, 10, &param); - if (ret || (is_kprobe && param > PARAM_MAX_STACK)) + if (ret || ((flags & TPARG_FL_KERNEL) && + param > PARAM_MAX_STACK)) ret = -EINVAL; else { code->op = FETCH_OP_STACK; @@ -197,6 +197,18 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, ret = -EINVAL; } else if (strcmp(arg, "comm") == 0) { code->op = FETCH_OP_COMM; +#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API + } else if (((flags & TPARG_FL_MASK) == + (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) && + strncmp(arg, "arg", 3) == 0) { + if (!isdigit(arg[3])) + return -EINVAL; + ret = kstrtoul(arg + 3, 10, &param); + if (ret || !param || param > PARAM_MAX_STACK) + return -EINVAL; + code->op = FETCH_OP_ARG; + code->param = (unsigned int)param - 1; +#endif } else ret = -EINVAL;

@@ -207,7 +219,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, static int parse_probe_arg(char *arg, const struct fetch_type *type, struct fetch_insn **pcode, struct fetch_insn *end, - bool is_return, bool is_kprobe) + unsigned int flags) { struct fetch_insn *code = *pcode; unsigned long param; @@ -217,8 +229,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,

switch (arg[0]) { case '$': - ret = parse_probe_vars(arg + 1, type, code, - is_return, is_kprobe); + ret = parse_probe_vars(arg + 1, type, code, flags); break;

case '%': /* named register */ @@ -240,7 +251,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type, code->immediate = param; } else if (arg[1] == '+') { /* kprobes don't support file offsets */ - if (is_kprobe) + if (flags & TPARG_FL_KERNEL) return -EINVAL;

ret = kstrtol(arg + 2, 0, &offset); @@ -251,7 +262,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type, code->immediate = (unsigned long)offset; // imm64? } else { /* uprobes don't support symbols */ - if (!is_kprobe) + if (!(flags & TPARG_FL_KERNEL)) return -EINVAL;

ret = traceprobe_split_symbol_offset(arg + 1, &offset); @@ -292,8 +303,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type, const struct fetch_type *t2 = find_fetch_type(NULL);

*tmp = '\0'; - ret = parse_probe_arg(arg, t2, &code, end, is_return, - is_kprobe); + ret = parse_probe_arg(arg, t2, &code, end, flags); if (ret) break; if (code->op == FETCH_OP_COMM) @@ -353,7 +363,7 @@ static int __parse_bitfield_probe_arg(const char *bf,

/* String length checking wrapper */ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return, bool is_kprobe) + struct probe_arg *parg, unsigned int flags) { struct fetch_insn *code, *tmp = NULL; const char *t; @@ -393,7 +403,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;

ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], - is_return, is_kprobe); + flags); if (ret) goto fail;

diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index ef477bd8468a..ff91faf70887 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -35,6 +35,7 @@ #include <linux/stringify.h> #include <linux/limits.h> #include <linux/uaccess.h> +#include <linux/bitops.h> #include <asm/bitsperlong.h>

#include "trace.h" @@ -89,6 +90,7 @@ enum fetch_op { FETCH_OP_RETVAL, /* Return value */ FETCH_OP_IMM, /* Immediate : .immediate */ FETCH_OP_COMM, /* Current comm */ + FETCH_OP_ARG, /* Function argument : .param */ FETCH_OP_FOFFS, /* File offset: .immediate */ // Stage 2 (dereference) op FETCH_OP_DEREF, /* Dereference: .offset */ @@ -261,8 +263,13 @@ find_event_file_link(struct trace_probe *tp, struct trace_event_file *file) return NULL; }

+#define TPARG_FL_RETURN BIT(0) +#define TPARG_FL_KERNEL BIT(1) +#define TPARG_FL_FENTRY BIT(2) +#define TPARG_FL_MASK GENMASK(2, 0) + extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, - struct probe_arg *parg, bool is_return, bool is_kprobe); + struct probe_arg *parg, unsigned int flags);

extern int traceprobe_conflict_field_name(const char *name, struct probe_arg *args, int narg); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 64c1fbe087a1..e15da2281855 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -519,7 +519,7 @@ static int create_trace_uprobe(int argc, char **argv)

/* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg, - is_return, false); + is_return ? TPARG_FL_RETURN : 0); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error;

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Add a testcase for symbol type with kprobe event. This tests good/bad syntax combinations and also the traced data. If the kernel doesn't support symbol type, it skips the test as UNSUPPORTED.

Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- .../ftrace/test.d/kprobe/kprobe_args_symbol.tc | 73 ++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc

diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc new file mode 100644 index 000000000000..a5820b175df5 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc @@ -0,0 +1,73 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Kprobe event argument symbol type + +[ -f kprobe_events ] || exit_unsupported # this is configurable + +grep -qe "type:.* symbol" README || exit_unsupported # version issue + +echo 0 > events/enable +echo > kprobe_events + +PROBEFUNC="vfs_read" +GOODREG= +BADREG= +GOODSYM="_sdata" +if ! grep -qw ${GOODSYM} /proc/kallsyms ; then + GOODSYM=$PROBEFUNC +fi + +case `uname -m` in +x86_64|i[3456]86) + GOODREG=%ax + BADREG=%ex +;; +aarch64) + GOODREG=%x0 + BADREG=%ax +;; +arm*) + GOODREG=%r0 + BADREG=%ax +;; +*) + echo "Please implement other architecture here" + exit_untested +esac + +test_goodarg() # Good-args +{ + while [ "$1" ]; do + echo "p ${PROBEFUNC} $1" > kprobe_events + shift 1 + done; +} + +test_badarg() # Bad-args +{ + while [ "$1" ]; do + ! echo "p ${PROBEFUNC} $1" > kprobe_events + shift 1 + done; +} + +echo > kprobe_events + +: "Symbol type" +test_goodarg "${GOODREG}:symbol" "@${GOODSYM}:symbol" "@${GOODSYM}+10:symbol" \ + "$stack0:symbol" "+0($stack):symbol" +test_badarg "$comm:symbol" + +: "Retval with symbol type" +echo "r ${PROBEFUNC} $retval:symbol" > kprobe_events + +echo > kprobe_events + +: "Test get symbol" +echo 'p:testprobe create_trace_kprobe $stack0:symbol' > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo test >> kprobe_events +tail -n 1 trace | grep -q "arg1=trace_run_command" + +echo 0 > events/enable +echo > kprobe_events

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Add a testcase for array type with kprobe event. This tests good/bad syntax combinations and also the traced data is correct in several way. If the kernel doesn't support array type, it skips the test as UNSUPPORTED.

Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- .../ftrace/test.d/kprobe/kprobe_args_array.tc | 75 ++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_array.tc

diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_array.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_array.tc new file mode 100644 index 000000000000..27c9628c1fff --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_array.tc @@ -0,0 +1,75 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Kprobe event array argument + +[ -f kprobe_events ] || exit_unsupported # this is configurable + +grep -q "<type>[<array-size>]" README || exit_unsupported # version issue + +GOODSYM="_sdata" +if ! grep -qw ${GOODSYM} /proc/kallsyms ; then + GOODSYM="create_trace_kprobe" +fi +case `uname -m` in +x86_64) + ARG2=%si + OFFS=8 +;; +i[3456]86) + ARG2=%cx + OFFS=4 +;; +aarch64) + ARG2=%x1 + OFFS=8 +;; +arm*) + ARG2=%r1 + OFFS=4 +;; +*) + echo "Please implement other architecture here" + exit_untested +esac + +create_testprobe() { # args + echo "p:testprobe create_trace_kprobe $*" > kprobe_events +} + +echo 0 > events/enable +echo > kprobe_events + +: "Syntax test" +create_testprobe "+0(${ARG2}):x8[1] +0(${ARG2}):s16[1] +0(${ARG2}):u32[1]" +create_testprobe "+0(${ARG2}):x64[1] +0(${ARG2}):symbol[1]" +create_testprobe "+0(${ARG2}):b2@3/8[1] +0(${ARG2}):string[1]" +create_testprobe "+0(${ARG2}):x8[64] @${GOODSYM}:x8[4]" + +! create_testprobe "${ARG2}:x8[1]" # Can not use array type on register +! create_testprobe "$comm:x8[1]" # Can not use array type on $comm +! create_testprobe "$comm:string[1]" # No, even if it is string array +! create_testprobe "+0(${ARG2}):x64[0]" # array size >= 1 +! create_testprobe "+0(${ARG2}):x64[65]" # array size <= 64 + +: "Test get argument (1)" +create_testprobe "arg1=+0(${ARG2}):string[1]" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo test >> kprobe_events +tail -n 1 trace | grep -qe "testprobe.* arg1={"test"}" +echo 0 > events/kprobes/testprobe/enable + +: "Test get argument (2)" +create_testprobe "arg1=+0(${ARG2}):string[3]" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo foo bar buzz >> kprobe_events +tail -n 1 trace | grep -qe "testprobe.* arg1={"foo","bar","buzz"}" +echo 0 > events/kprobes/testprobe/enable + +: "Test get argument (3)" +create_testprobe "arg1=+0(+0(${ARG2})):u8[4]" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo 1234 >> kprobe_events +tail -n 1 trace | grep -qe "testprobe.* arg1={49,50,51,52}" # ascii code +echo 0 > events/kprobes/testprobe/enable + +echo > kprobe_events

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In Documentation/trace/kprobetrace.txt, it says

@SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)

However, the parser doesn't parse minus offset correctly, since commit 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") drops minus ("-") offset support for kprobe probe address usage.

This fixes the traceprobe_split_symbol_offset() to parse minus offset again with checking the offset range, and add a minus offset check in kprobe probe address usage.

Fixes: 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- Changes in v2.1: - Fix to ensure the offset value is less than LONG_MAX. - Fail if the offset is minus when traceprobe_split_symbol_offset() is used for the probe address. - Add Fixes tag. --- kernel/trace/trace_kprobe.c | 4 ++-- kernel/trace/trace_probe.c | 15 ++++++++++----- kernel/trace/trace_probe.h | 2 +- 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 5ce9b8cf7be3..b5b1d8aa47d6 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -667,7 +667,7 @@ static int create_trace_kprobe(int argc, char **argv) char *symbol = NULL, *event = NULL, *group = NULL; int maxactive = 0; char *arg; - unsigned long offset = 0; + long offset = 0; void *addr = NULL; char buf[MAX_EVENT_NAME_LEN];

@@ -755,7 +755,7 @@ static int create_trace_kprobe(int argc, char **argv) symbol = argv[1]; /* TODO: support .init module functions */ ret = traceprobe_split_symbol_offset(symbol, &offset); - if (ret) { + if (ret || offset < 0) { pr_info("Failed to parse either an address or a symbol.\n"); return ret; } diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index d59357308677..ec3856147fdd 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -320,21 +320,26 @@ static fetch_func_t get_fetch_size_function(const struct fetch_type *type, }

/* Split symbol and offset. */ -int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) +int traceprobe_split_symbol_offset(char *symbol, long *offset) { + unsigned long ul; char *tmp; int ret;

if (!offset) return -EINVAL;

- tmp = strchr(symbol, '+'); + tmp = strpbrk(symbol, "+-"); if (tmp) { - /* skip sign because kstrtoul doesn't accept '+' */ - ret = kstrtoul(tmp + 1, 0, offset); + ret = kstrtoul(tmp + 1, 0, &ul); if (ret) return ret; - + if (ul > LONG_MAX) + return -E2BIG; + if (*tmp == '-') + *offset = -ul; + else + *offset = ul; *tmp = '\0'; } else *offset = 0; diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 0745f895f780..75daff22ccea 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -365,7 +365,7 @@ extern int traceprobe_conflict_field_name(const char *name, extern void traceprobe_update_arg(struct probe_arg *arg); extern void traceprobe_free_probe_arg(struct probe_arg *arg);

-extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); +extern int traceprobe_split_symbol_offset(char *symbol, long *offset);

/* Sum up total data length for dynamic arraies (strings) */ static nokprobe_inline int

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On Thu, 22 Feb 2018 00:01:29 +0900 Masami Hiramatsu mhiramat@kernel.org wrote:

Add a testcase for symbol type with kprobe event. This tests good/bad syntax combinations and also the traced data. If the kernel doesn't support symbol type, it skips the test as UNSUPPORTED.

Signed-off-by: Masami Hiramatsu mhiramat@kernel.org

.../ftrace/test.d/kprobe/kprobe_args_symbol.tc | 73 ++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc

diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc new file mode 100644 index 000000000000..a5820b175df5 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_symbol.tc @@ -0,0 +1,73 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Kprobe event argument symbol type

+[ -f kprobe_events ] || exit_unsupported # this is configurable

+grep -qe "type:.* symbol" README || exit_unsupported # version issue

+echo 0 > events/enable +echo > kprobe_events

+PROBEFUNC="vfs_read" +GOODREG= +BADREG= +GOODSYM="_sdata" +if ! grep -qw ${GOODSYM} /proc/kallsyms ; then

• GOODSYM=$PROBEFUNC

+fi

+case `uname -m` in +x86_64|i[3456]86)

• GOODREG=%ax
• BADREG=%ex

+;; +aarch64)

• GOODREG=%x0
• BADREG=%ax

+;; +arm*)

• GOODREG=%r0
• BADREG=%ax

+;; +*)

• echo "Please implement other architecture here"
• exit_untested

+esac

+test_goodarg() # Good-args +{

• while [ "$1" ]; do
• echo "p ${PROBEFUNC} $1" > kprobe_events
• shift 1
• done;

+}

+test_badarg() # Bad-args +{

• while [ "$1" ]; do
• ! echo "p ${PROBEFUNC} $1" > kprobe_events
• shift 1
• done;

+}

+echo > kprobe_events

+: "Symbol type" +test_goodarg "${GOODREG}:symbol" "@${GOODSYM}:symbol" "@${GOODSYM}+10:symbol" \

• "\$stack0:symbol" "+0(\$stack):symbol"
  

+test_badarg "$comm:symbol"

+: "Retval with symbol type" +echo "r ${PROBEFUNC} $retval:symbol" > kprobe_events

+echo > kprobe_events

+: "Test get symbol" +echo 'p:testprobe create_trace_kprobe $stack0:symbol' > kprobe_events +echo 1 > events/kprobes/testprobe/enable +! echo test >> kprobe_events +tail -n 1 trace | grep -q "arg1=trace_run_command"

Hmm, this works only on x86 and other arch which stores return address on top of stack. I'll find some other good point to test it.

Thanks,

+echo 0 > events/enable +echo > kprobe_events

On Wed, Feb 21, 2018 at 11:57:36PM +0900, Masami Hiramatsu wrote:

Replace {k,u}probe event argument fetching framework with switch-case based. Currently that is implemented with structures, macros and chain of function-pointers, which is more complicated than necessary and may get a performance penalty by retpoline.

This simplify that with an array of "fetch_insn" (opcode and oprands), and make process_fetch_insn() just interprets it. No function pointers are used.

I think it'd be nice to split this commit to 3 parts:

* convert to the fetch_insn * remove fetch methods (now unused) * unify fetch type table

Thanks, Namhyung

Signed-off-by: Masami Hiramatsu mhiramat@kernel.org

Changes in v2:

• Allow $comm:string.

---

kernel/trace/trace_kprobe.c | 314 +++++++++++----------------- kernel/trace/trace_probe.c | 441 ++++++++++++--------------------------- kernel/trace/trace_probe.h | 232 ++++----------------- kernel/trace/trace_probe_tmpl.h | 120 +++++++++++ kernel/trace/trace_uprobe.c | 150 +++++++------ 5 files changed, 517 insertions(+), 740 deletions(-) create mode 100644 kernel/trace/trace_probe_tmpl.h

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index a96328dfc012..5dd2d470cc7e 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -24,6 +24,7 @@ #include <linux/error-injection.h> #include "trace_probe.h" +#include "trace_probe_tmpl.h" #define KPROBE_EVENT_SYSTEM "kprobes" #define KRETPROBE_MAXACTIVE_MAX 4096 @@ -121,184 +122,6 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs); -/* Memory fetching by symbol */ -struct symbol_cache {

• char *symbol;
• long offset;
• unsigned long addr;

-};

-unsigned long update_symbol_cache(struct symbol_cache *sc) -{

• sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
• if (sc->addr)

• sc->addr += sc->offset;
  

• return sc->addr;

-}

-void free_symbol_cache(struct symbol_cache *sc) -{

• kfree(sc->symbol);
• kfree(sc);

-}

-struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) -{

• struct symbol_cache *sc;
• if (!sym || strlen(sym) == 0)

• return NULL;
  

• sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
• if (!sc)

• return NULL;
  

• sc->symbol = kstrdup(sym, GFP_KERNEL);
• if (!sc->symbol) {

• kfree(sc);
  

• return NULL;
  

• }
• sc->offset = offset;
• update_symbol_cache(sc);
• return sc;

-}

-/*

• • Kprobes-specific fetch functions
• */

-#define DEFINE_FETCH_stack(type) \ -static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \

• 			  void *offset, void *dest)	\
  

-{ \

• *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \

• 		(unsigned int)((unsigned long)offset));	\
  

-} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type));

-DEFINE_BASIC_FETCH_FUNCS(stack) -/* No string on the stack entry */ -#define fetch_stack_string NULL -#define fetch_stack_string_size NULL

-#define DEFINE_FETCH_memory(type) \ -static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \

• 			  void *addr, void *dest)	\
  

-{ \

• type retval; \
• if (probe_kernel_address(addr, retval)) \

• *(type *)dest = 0;					\
  

• else \

• *(type *)dest = retval;					\
  

-} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type));

-DEFINE_BASIC_FETCH_FUNCS(memory) -/*

• • Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
• • length and relative data location.
• */

-static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,

• 			    void *addr, void *dest)
  

-{

• int maxlen = get_rloc_len(*(u32 *)dest);
• u8 *dst = get_rloc_data(dest);
• long ret;
• if (!maxlen)

• return;
  

• /*

• * Try to get string again, since the string can be changed while
  

• * probing.
  

• */
  

• ret = strncpy_from_unsafe(dst, addr, maxlen);
• if (ret < 0) { /* Failed to fetch string */

• dst[0] = '\0';
  

• *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
  

• } else {

• *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
  

• }

-} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string));

-/* Return the length of string -- including null terminal byte */ -static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,

• 				 void *addr, void *dest)
  

-{

• mm_segment_t old_fs;
• int ret, len = 0;
• u8 c;
• old_fs = get_fs();
• set_fs(KERNEL_DS);
• pagefault_disable();
• do {

• ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
  

• len++;
  

• } while (c && ret == 0 && len < MAX_STRING_SIZE);
• pagefault_enable();
• set_fs(old_fs);
• if (ret < 0) /* Failed to check the length */

• *(u32 *)dest = 0;
  

• else

• *(u32 *)dest = len;
  

-} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size));

-#define DEFINE_FETCH_symbol(type) \ -void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\ -{ \

• struct symbol_cache *sc = data; \
• if (sc->addr) \

• fetch_memory_##type(regs, (void *)sc->addr, dest);	\
  

• else \

• *(type *)dest = 0;					\
  

-} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type));

-DEFINE_BASIC_FETCH_FUNCS(symbol) -DEFINE_FETCH_symbol(string) -DEFINE_FETCH_symbol(string_size)

-/* kprobes don't support file_offset fetch methods */ -#define fetch_file_offset_u8 NULL -#define fetch_file_offset_u16 NULL -#define fetch_file_offset_u32 NULL -#define fetch_file_offset_u64 NULL -#define fetch_file_offset_string NULL -#define fetch_file_offset_string_size NULL

-/* Fetch type information table */ -static const struct fetch_type kprobes_fetch_type_table[] = {

• /* Special types */
• [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,

• 			sizeof(u32), 1, "__data_loc char[]"),
  

• [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,

• 			string_size, sizeof(u32), 0, "u32"),
  

• /* Basic types */
• ASSIGN_FETCH_TYPE(u8, u8, 0),
• ASSIGN_FETCH_TYPE(u16, u16, 0),
• ASSIGN_FETCH_TYPE(u32, u32, 0),
• ASSIGN_FETCH_TYPE(u64, u64, 0),
• ASSIGN_FETCH_TYPE(s8, u8, 1),
• ASSIGN_FETCH_TYPE(s16, u16, 1),
• ASSIGN_FETCH_TYPE(s32, u32, 1),
• ASSIGN_FETCH_TYPE(s64, u64, 1),
• ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
• ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
• ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
• ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
• ASSIGN_FETCH_TYPE_END

-};

/*

• Allocate new trace_probe and initialize it (including kprobes).

*/ @@ -490,14 +313,11 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) /* Internal register function - just handle k*probes and flags */ static int __register_trace_kprobe(struct trace_kprobe *tk) {

• int i, ret;

• int ret;

if (trace_probe_is_registered(&tk->tp)) return -EINVAL;

• for (i = 0; i < tk->tp.nr_args; i++)

• traceprobe_update_arg(&tk->tp.args[i]);
  

• /* Set/clear disabled flag according to tp->flag */ if (trace_probe_is_enabled(&tk->tp)) tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;

@@ -830,8 +650,7 @@ static int create_trace_kprobe(int argc, char **argv) /* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg,

• 				is_return, true,
  

• 				kprobes_fetch_type_table);
  

• 				 is_return, true);
  

  if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error;

@@ -985,6 +804,133 @@ static const struct file_operations kprobe_profile_ops = { .release = seq_release, }; +/* Kprobe specific fetch functions */

+/* Return the length of string -- including null terminal byte */ +static nokprobe_inline void +fetch_store_strlen(unsigned long addr, void *dest) +{

• mm_segment_t old_fs;
• int ret, len = 0;
• u8 c;
• old_fs = get_fs();
• set_fs(KERNEL_DS);
• pagefault_disable();
• do {

• ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
  

• len++;
  

• } while (c && ret == 0 && len < MAX_STRING_SIZE);
• pagefault_enable();
• set_fs(old_fs);
• if (ret < 0) /* Failed to check the length */

• *(u32 *)dest = 0;
  

• else

• *(u32 *)dest = len;
  

+}

+/*

• • Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
• • length and relative data location.
• */

+static nokprobe_inline void +fetch_store_string(unsigned long addr, void *dest) +{

• int maxlen = get_rloc_len(*(u32 *)dest);
• u8 *dst = get_rloc_data(dest);
• long ret;
• if (!maxlen)

• return;
  

• /*

• * Try to get string again, since the string can be changed while
  

• * probing.
  

• */
  

• ret = strncpy_from_unsafe(dst, (void *)addr, maxlen);
• if (ret < 0) { /* Failed to fetch string */

• dst[0] = '\0';
  

• *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
  

• } else {

• *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
  

• }

+}

+/* Note that we don't verify it, since the code does not come from user space */ +static int +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,

•    bool pre)
  

+{

• unsigned long val;
• int ret;
• /* 1st stage: get value from context */
• switch (code->op) {
• case FETCH_OP_REG:

• val = regs_get_register(regs, code->param);
  

• break;
  

• case FETCH_OP_STACK:

• val = regs_get_kernel_stack_nth(regs, code->param);
  

• break;
  

• case FETCH_OP_STACKP:

• val = kernel_stack_pointer(regs);
  

• break;
  

• case FETCH_OP_RETVAL:

• val = regs_return_value(regs);
  

• break;
  

• case FETCH_OP_IMM:

• val = code->immediate;
  

• break;
  

• case FETCH_OP_COMM:

• val = (unsigned long)current->comm;
  

• break;
  

• default:

• return -EILSEQ;
  

• }
• code++;
• /* 2nd stage: dereference memory if needed */
• while (code->op == FETCH_OP_DEREF) {

• ret = probe_kernel_read(&val, (void *)val + code->offset,
  

• 			sizeof(val));
  

• if (ret)
  

• 	return ret;
  

• code++;
  

• }
• /* 3rd stage: store value to buffer */
• switch (code->op) {
• case FETCH_OP_ST_RAW:

• fetch_store_raw(val, code, dest);
  

• break;
  

• case FETCH_OP_ST_MEM:

• probe_kernel_read(dest, (void *)val + code->offset, code->size);
  

• break;
  

• case FETCH_OP_ST_STRING:

• if (pre)
  

• 	fetch_store_strlen(val + code->offset, dest);
  

• else
  

• 	fetch_store_string(val + code->offset, dest);
  

• break;
  

• default:

• return -EILSEQ;
  

• }
• code++;
• /* 4th stage: modify stored value if needed */
• if (code->op == FETCH_OP_MOD_BF) {

• fetch_apply_bitfield(code, dest);
  

• code++;
  

• }
• return code->op == FETCH_OP_END ? 0 : -EILSEQ;

+} +NOKPROBE_SYMBOL(process_fetch_insn)

/* Kprobe handler */ static nokprobe_inline void __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 37bdd56b4988..cd87490b3492 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -73,176 +73,29 @@ int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) const char PRINT_TYPE_FMT_NAME(string)[] = "\"%s\""; -#define CHECK_FETCH_FUNCS(method, fn) \

• (((FETCH_FUNC_NAME(method, u8) == fn) || \

•  (FETCH_FUNC_NAME(method, u16) == fn) ||	\
  

•  (FETCH_FUNC_NAME(method, u32) == fn) ||	\
  

•  (FETCH_FUNC_NAME(method, u64) == fn) ||	\
  

•  (FETCH_FUNC_NAME(method, string) == fn) ||	\
  

•  (FETCH_FUNC_NAME(method, string_size) == fn)) \
  

• && (fn != NULL))
  

-/* Data fetch function templates */ -#define DEFINE_FETCH_reg(type) \ -void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, void *offset, void *dest) \ -{ \

• *(type *)dest = (type)regs_get_register(regs, \

• 		(unsigned int)((unsigned long)offset));	\
  

-} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type)); -DEFINE_BASIC_FETCH_FUNCS(reg) -/* No string on the register */ -#define fetch_reg_string NULL -#define fetch_reg_string_size NULL

-#define DEFINE_FETCH_retval(type) \ -void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \

• 		   void *dummy, void *dest)		\
  

-{ \

• *(type *)dest = (type)regs_return_value(regs); \

-} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type)); -DEFINE_BASIC_FETCH_FUNCS(retval) -/* No string on the retval */ -#define fetch_retval_string NULL -#define fetch_retval_string_size NULL

-/* Dereference memory access function */ -struct deref_fetch_param {

• struct fetch_param orig;
• long offset;
• fetch_func_t fetch;
• fetch_func_t fetch_size;

-};

-#define DEFINE_FETCH_deref(type) \ -void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \

• 		  void *data, void *dest)		\
  

-{ \

• struct deref_fetch_param *dprm = data; \
• unsigned long addr; \
• call_fetch(&dprm->orig, regs, &addr); \
• if (addr) { \

• addr += dprm->offset;					\
  

• dprm->fetch(regs, (void *)addr, dest);			\
  

• } else \

• *(type *)dest = 0;					\
  

-} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type)); -DEFINE_BASIC_FETCH_FUNCS(deref) -DEFINE_FETCH_deref(string)

-void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs,

• 			 void *data, void *dest)
  

-{

• struct deref_fetch_param *dprm = data;
• unsigned long addr;
• call_fetch(&dprm->orig, regs, &addr);
• if (addr && dprm->fetch_size) {

• addr += dprm->offset;
  

• dprm->fetch_size(regs, (void *)addr, dest);
  

• } else

• *(string_size *)dest = 0;
  

-} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size));

-static void update_deref_fetch_param(struct deref_fetch_param *data) -{

• if (CHECK_FETCH_FUNCS(deref, data->orig.fn))

• update_deref_fetch_param(data->orig.data);
  

• else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))

• update_symbol_cache(data->orig.data);
  

-} -NOKPROBE_SYMBOL(update_deref_fetch_param);

-static void free_deref_fetch_param(struct deref_fetch_param *data) -{

• if (CHECK_FETCH_FUNCS(deref, data->orig.fn))

• free_deref_fetch_param(data->orig.data);
  

• else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))

• free_symbol_cache(data->orig.data);
  

• kfree(data);

-} -NOKPROBE_SYMBOL(free_deref_fetch_param);

-/* Bitfield fetch function */ -struct bitfield_fetch_param {

• struct fetch_param orig;
• unsigned char hi_shift;
• unsigned char low_shift;

+/* Fetch type information table */ +static const struct fetch_type probe_fetch_types[] = {

• /* Special types */
• __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1,

• 	    "__data_loc char[]"),
  

• /* Basic types */
• ASSIGN_FETCH_TYPE(u8, u8, 0),
• ASSIGN_FETCH_TYPE(u16, u16, 0),
• ASSIGN_FETCH_TYPE(u32, u32, 0),
• ASSIGN_FETCH_TYPE(u64, u64, 0),
• ASSIGN_FETCH_TYPE(s8, u8, 1),
• ASSIGN_FETCH_TYPE(s16, u16, 1),
• ASSIGN_FETCH_TYPE(s32, u32, 1),
• ASSIGN_FETCH_TYPE(s64, u64, 1),
• ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
• ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
• ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
• ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
• ASSIGN_FETCH_TYPE_END

}; -#define DEFINE_FETCH_bitfield(type) \ -void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \

• 		     void *data, void *dest)		\
  

-{ \

• struct bitfield_fetch_param *bprm = data; \
• type buf = 0; \
• call_fetch(&bprm->orig, regs, &buf); \
• if (buf) { \

• buf <<= bprm->hi_shift;					\
  

• buf >>= bprm->low_shift;				\
  

• } \
• *(type *)dest = buf; \

-} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type)); -DEFINE_BASIC_FETCH_FUNCS(bitfield) -#define fetch_bitfield_string NULL -#define fetch_bitfield_string_size NULL

-static void -update_bitfield_fetch_param(struct bitfield_fetch_param *data) -{

• /*

• * Don't check the bitfield itself, because this must be the
  

• * last fetch function.
  

• */
  

• if (CHECK_FETCH_FUNCS(deref, data->orig.fn))

• update_deref_fetch_param(data->orig.data);
  

• else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))

• update_symbol_cache(data->orig.data);
  

-}

-static void -free_bitfield_fetch_param(struct bitfield_fetch_param *data) -{

• /*

• * Don't check the bitfield itself, because this must be the
  

• * last fetch function.
  

• */
  

• if (CHECK_FETCH_FUNCS(deref, data->orig.fn))

• free_deref_fetch_param(data->orig.data);
  

• else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))

• free_symbol_cache(data->orig.data);
  

• kfree(data);

-}

-void FETCH_FUNC_NAME(comm, string)(struct pt_regs *regs,

• 			  void *data, void *dest)
  

-{

• int maxlen = get_rloc_len(*(u32 *)dest);
• u8 *dst = get_rloc_data(dest);
• long ret;
• if (!maxlen)

• return;
  

• ret = strlcpy(dst, current->comm, maxlen);
• *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));

-} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string));

-void FETCH_FUNC_NAME(comm, string_size)(struct pt_regs *regs,

• 			       void *data, void *dest)
  

-{

• *(u32 *)dest = strlen(current->comm) + 1;

-} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string_size));

-static const struct fetch_type *find_fetch_type(const char *type,

• 				const struct fetch_type *ftbl)
  

+static const struct fetch_type *find_fetch_type(const char *type) { int i; @@ -263,58 +116,27 @@ static const struct fetch_type *find_fetch_type(const char *type, switch (bs) { case 8:

• 	return find_fetch_type("u8", ftbl);
  

• 	return find_fetch_type("u8");
  

  case 16:

• 	return find_fetch_type("u16", ftbl);
  

• 	return find_fetch_type("u16");
  

  case 32:

• 	return find_fetch_type("u32", ftbl);
  

• 	return find_fetch_type("u32");
  

  case 64:

• 	return find_fetch_type("u64", ftbl);
  

• 	return find_fetch_type("u64");
  

  default: goto fail; } }

• for (i = 0; ftbl[i].name; i++) {

• if (strcmp(type, ftbl[i].name) == 0)
  

• 	return &ftbl[i];
  

• for (i = 0; probe_fetch_types[i].name; i++) {

• if (strcmp(type, probe_fetch_types[i].name) == 0)
  

• 	return &probe_fetch_types[i];
  

  }

fail: return NULL; } -/* Special function : only accept unsigned long */ -static void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest) -{

• *(unsigned long *)dest = kernel_stack_pointer(regs);

-} -NOKPROBE_SYMBOL(fetch_kernel_stack_address);

-static void fetch_user_stack_address(struct pt_regs *regs, void *dummy, void *dest) -{

• *(unsigned long *)dest = user_stack_pointer(regs);

-} -NOKPROBE_SYMBOL(fetch_user_stack_address);

-static fetch_func_t get_fetch_size_function(const struct fetch_type *type,

• 			    fetch_func_t orig_fn,
  

• 			    const struct fetch_type *ftbl)
  

-{

• int i;
• if (type != &ftbl[FETCH_TYPE_STRING])

• return NULL;	/* Only string type needs size function */
  

• for (i = 0; i < FETCH_MTD_END; i++)

• if (type->fetch[i] == orig_fn)
  

• 	return ftbl[FETCH_TYPE_STRSIZE].fetch[i];
  

• WARN_ON(1); /* This should not happen */
• return NULL;

-}

/* Split symbol and offset. */ int traceprobe_split_symbol_offset(char *symbol, long *offset) { @@ -341,7 +163,7 @@ int traceprobe_split_symbol_offset(char *symbol, long *offset) #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) static int parse_probe_vars(char *arg, const struct fetch_type *t,

• 	    struct fetch_param *f, bool is_return,
  

• 	    struct fetch_insn *code, bool is_return,
      bool is_kprobe)
  

{ int ret = 0; @@ -349,33 +171,24 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, if (strcmp(arg, "retval") == 0) { if (is_return)

• 	f->fn = t->fetch[FETCH_MTD_retval];
  

• 	code->op = FETCH_OP_RETVAL;
  

  else ret = -EINVAL; } else if (strncmp(arg, "stack", 5) == 0) { if (arg[5] == '\0') {

• 	if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR))
  

• 		return -EINVAL;
  

• 	if (is_kprobe)
  

• 		f->fn = fetch_kernel_stack_address;
  

• 	else
  

• 		f->fn = fetch_user_stack_address;
  

• 	code->op = FETCH_OP_STACKP;
  

  } else if (isdigit(arg[5])) { ret = kstrtoul(arg + 5, 10, &param); if (ret || (is_kprobe && param > PARAM_MAX_STACK)) ret = -EINVAL; else {

• 		f->fn = t->fetch[FETCH_MTD_stack];
  

• 		f->data = (void *)param;
  

• 		code->op = FETCH_OP_STACK;
  

• 		code->param = (unsigned int)param;
  }
  

  } else ret = -EINVAL; } else if (strcmp(arg, "comm") == 0) {

• if (strcmp(t->name, "string") != 0 &&
  

•     strcmp(t->name, "string_size") != 0)
  

• 	return -EINVAL;
  

• f->fn = t->fetch[FETCH_MTD_comm];
  

• code->op = FETCH_OP_COMM;
  

  } else ret = -EINVAL;

@@ -383,10 +196,12 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, } /* Recursive argument parser */ -static int parse_probe_arg(char *arg, const struct fetch_type *t,

•      struct fetch_param *f, bool is_return, bool is_kprobe,
  

•      const struct fetch_type *ftbl)
  

+static int +parse_probe_arg(char *arg, const struct fetch_type *type,

• struct fetch_insn **pcode, struct fetch_insn *end,
  

• bool is_return, bool is_kprobe)
  

{

• struct fetch_insn *code = *pcode; unsigned long param; long offset; char *tmp;

@@ -394,14 +209,15 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, switch (arg[0]) { case '$':

• ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe);
  

• ret = parse_probe_vars(arg + 1, type, code,
  

• 			is_return, is_kprobe);
  

  break;

case '%': /* named register */ ret = regs_query_register_offset(arg + 1); if (ret >= 0) {

• 	f->fn = t->fetch[FETCH_MTD_reg];
  

• 	f->data = (void *)(unsigned long)ret;
  

• 	code->op = FETCH_OP_REG;
  

• 	code->param = (unsigned int)ret;
  ret = 0;
  

  } break;

@@ -411,9 +227,9 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, ret = kstrtoul(arg + 1, 0, &param); if (ret) break;

• 	f->fn = t->fetch[FETCH_MTD_memory];
  

• 	f->data = (void *)param;
  

• 	/* load address */
  

• 	code->op = FETCH_OP_IMM;
  

• 	code->immediate = param;
  

  } else if (arg[1] == '+') { /* kprobes don't support file offsets */ if (is_kprobe)

@@ -423,8 +239,8 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, if (ret) break;

• 	f->fn = t->fetch[FETCH_MTD_file_offset];
  

• 	f->data = (void *)offset;
  

• 	code->op = FETCH_OP_FOFFS;
  

• 	code->immediate = (unsigned long)offset;  // imm64?
  

  } else { /* uprobes don't support symbols */ if (!is_kprobe)

@@ -434,10 +250,19 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, if (ret) break;

• 	f->data = alloc_symbol_cache(arg + 1, offset);
  

• 	if (f->data)
  

• 		f->fn = t->fetch[FETCH_MTD_symbol];
  

• 	code->op = FETCH_OP_IMM;
  

• 	code->immediate =
  

• 		(unsigned long)kallsyms_lookup_name(arg + 1);
  

• 	if (!code->immediate)
  

• 		return -ENOENT;
  

• 	code->immediate += offset;
  

  }

• /* These are fetching from memory */
  

• if (++code == end)
  

• 	return -E2BIG;
  

• *pcode = code;
  

• code->op = FETCH_OP_DEREF;
  

• code->offset = offset;
  

  break;

case '+': /* deref memory */ @@ -445,11 +270,10 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, case '-': tmp = strchr(arg, '('); if (!tmp)

• 	break;
  

• 	return -EINVAL;
  

*tmp = '\0'; ret = kstrtol(arg, 0, &offset);

• if (ret) break;

@@ -457,36 +281,28 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, tmp = strrchr(arg, ')'); if (tmp) {

• 	struct deref_fetch_param	*dprm;
  

• 	const struct fetch_type		*t2;
  

• 	const struct fetch_type *t2 = find_fetch_type(NULL);
  

• 	t2 = find_fetch_type(NULL, ftbl);
  *tmp = '\0';
  

• 	dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
  

• 	if (!dprm)
  

• 		return -ENOMEM;
  

• 	dprm->offset = offset;
  

• 	dprm->fetch = t->fetch[FETCH_MTD_memory];
  

• 	dprm->fetch_size = get_fetch_size_function(t,
  

• 					dprm->fetch, ftbl);
  

• 	ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
  

• 					is_kprobe, ftbl);
  

• 	ret = parse_probe_arg(arg, t2, &code, end, is_return,
  

• 			      is_kprobe);
  if (ret)
  

• 		kfree(dprm);
  

• 	else {
  

• 		f->fn = t->fetch[FETCH_MTD_deref];
  

• 		f->data = (void *)dprm;
  

• 	}
  

• 		break;
  

• 	if (code->op == FETCH_OP_COMM)
  

• 		return -EINVAL;
  

• 	if (++code == end)
  

• 		return -E2BIG;
  

• 	*pcode = code;
  

• 	code->op = FETCH_OP_DEREF;
  

• 	code->offset = offset;
  

  } break; }

• if (!ret && !f->fn) { /* Parsed, but do not find fetch method */

• pr_info("%s type has no corresponding fetch method.\n", t->name);
  

• if (!ret && code->op == FETCH_OP_NOP) {

• /* Parsed, but do not find fetch method */
  

  ret = -EINVAL; }

• return ret;

} @@ -495,22 +311,15 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, /* Bitfield type needs to be parsed into a fetch function */ static int __parse_bitfield_probe_arg(const char *bf, const struct fetch_type *t,

• 		      struct fetch_param *f)
  

• 		      struct fetch_insn **pcode)
  

{

• struct bitfield_fetch_param *bprm;

• struct fetch_insn *code = *pcode; unsigned long bw, bo; char *tail;

if (*bf != 'b') return 0;

• bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
• if (!bprm)

• return -ENOMEM;
  

• bprm->orig = *f;
• f->fn = t->fetch[FETCH_MTD_bitfield];
• f->data = (void *)bprm; bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */

if (bw == 0 || *tail != '@') @@ -521,18 +330,24 @@ static int __parse_bitfield_probe_arg(const char *bf, if (tail == bf || *tail != '/') return -EINVAL;

• code++;
• if (code->op != FETCH_OP_NOP)

• return -E2BIG;
  

• *pcode = code;

• bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
• bprm->low_shift = bprm->hi_shift + bo;

• code->op = FETCH_OP_MOD_BF;
• code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
• code->rshift = BYTES_TO_BITS(t->size) - bw;
• code->basesize = t->size;

return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; } /* String length checking wrapper */ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,

• struct probe_arg *parg, bool is_return, bool is_kprobe,
  

• const struct fetch_type *ftbl)
  

• struct probe_arg *parg, bool is_return, bool is_kprobe)
  

{

• struct fetch_insn *code, *tmp = NULL; const char *t; int ret;

@@ -556,25 +371,67 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size, */ if (!t && strcmp(arg, "$comm") == 0) t = "string";

• parg->type = find_fetch_type(t, ftbl);

• parg->type = find_fetch_type(t); if (!parg->type) { pr_info("Unsupported type: %s\n", t); return -EINVAL; } parg->offset = *size; *size += parg->type->size;

• ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return,

• 	      is_kprobe, ftbl);
  

• if (ret >= 0 && t != NULL)

• ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
  

• if (ret >= 0) {

• parg->fetch_size.fn = get_fetch_size_function(parg->type,
  

• 					      parg->fetch.fn,
  

• 					      ftbl);
  

• parg->fetch_size.data = parg->fetch.data;
  

• code = tmp = kzalloc(sizeof(*code) * FETCH_INSN_MAX, GFP_KERNEL);
• if (!code)

• return -ENOMEM;
  

• code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
• ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],

• 	      is_return, is_kprobe);
  

• if (ret)

• goto fail;
  

• /* Store operation */
• if (!strcmp(parg->type->name, "string")) {

• if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM &&
  

•     code->op != FETCH_OP_COMM) {
  

• 	pr_info("string only accepts memory or address.\n");
  

• 	ret = -EINVAL;
  

• 	goto fail;
  

• }
  

• /* Since IMM or COMM must be the 1st insn, this is safe */
  

• if (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM)
  

• 	code++;
  

• code->op = FETCH_OP_ST_STRING;	/* In DEREF case, replace it */
  

• parg->dynamic = true;
  

• } else if (code->op == FETCH_OP_DEREF) {

• code->op = FETCH_OP_ST_MEM;
  

• code->size = parg->type->size;
  

• } else {

• code++;
  

• if (code->op != FETCH_OP_NOP) {
  

• 	ret = -E2BIG;
  

• 	goto fail;
  

• }
  

• code->op = FETCH_OP_ST_RAW;
  

• code->size = parg->type->size;
  

  }
• /* Modify operation */
• if (t != NULL) {

• ret = __parse_bitfield_probe_arg(t, parg->type, &code);
  

• if (ret)
  

• 	goto fail;
  

• }
• code++;
• code->op = FETCH_OP_END;
• /* Shrink down the code buffer */
• parg->code = kzalloc(sizeof(*code) * (code - tmp + 1), GFP_KERNEL);
• if (!parg->code)

• ret = -ENOMEM;
  

• else

• memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1));
  

+fail:

• kfree(tmp);

return ret; } @@ -596,25 +453,9 @@ int traceprobe_conflict_field_name(const char *name, return 0; } -void traceprobe_update_arg(struct probe_arg *arg) -{

• if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))

• update_bitfield_fetch_param(arg->fetch.data);
  

• else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))

• update_deref_fetch_param(arg->fetch.data);
  

• else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))

• update_symbol_cache(arg->fetch.data);
  

-}

void traceprobe_free_probe_arg(struct probe_arg *arg) {

• if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))

• free_bitfield_fetch_param(arg->fetch.data);
  

• else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))

• free_deref_fetch_param(arg->fetch.data);
  

• else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))

• free_symbol_cache(arg->fetch.data);
  

• kfree(arg->code); kfree(arg->name); kfree(arg->comm);

} diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index de928052926b..89d853ef5174 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -91,25 +91,50 @@ static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) return (u8 *)ent + get_rloc_offs(*dl); } -/* Data fetch function type */ -typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); /* Printing function type */ typedef int (*print_type_func_t)(struct trace_seq *, void *, void *); -/* Fetch types */ -enum {

• FETCH_MTD_reg = 0,
• FETCH_MTD_stack,
• FETCH_MTD_retval,
• FETCH_MTD_comm,
• FETCH_MTD_memory,
• FETCH_MTD_symbol,
• FETCH_MTD_deref,
• FETCH_MTD_bitfield,
• FETCH_MTD_file_offset,
• FETCH_MTD_END,

+enum fetch_op {

• FETCH_OP_NOP = 0,
• // Stage 1 (load) ops
• FETCH_OP_REG, /* Register : .param = offset */
• FETCH_OP_STACK, /* Stack : .param = index */
• FETCH_OP_STACKP, /* Stack pointer */
• FETCH_OP_RETVAL, /* Return value */
• FETCH_OP_IMM, /* Immediate : .immediate */
• FETCH_OP_COMM, /* Current comm */
• FETCH_OP_FOFFS, /* File offset: .immediate */
• // Stage 2 (dereference) op
• FETCH_OP_DEREF, /* Dereference: .offset */
• // Stage 3 (store) ops
• FETCH_OP_ST_RAW, /* Raw: .size */
• FETCH_OP_ST_MEM, /* Mem: .offset, .size */
• FETCH_OP_ST_STRING, /* String: .offset, .size */
• // Stage 4 (modify) op
• FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */
• FETCH_OP_END,

}; +struct fetch_insn {

• enum fetch_op op;
• union {

• unsigned int param;
  

• struct {
  

• 	unsigned int size;
  

• 	int offset;
  

• };
  

• struct {
  

• 	unsigned char basesize;
  

• 	unsigned char lshift;
  

• 	unsigned char rshift;
  

• };
  

• unsigned long immediate;
  

• };

+};

+/* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */ +#define FETCH_INSN_MAX 16

/* Fetch type information table */ struct fetch_type { const char *name; /* Name of type */ @@ -118,13 +143,6 @@ struct fetch_type { print_type_func_t print; /* Print functions */ const char *fmt; /* Fromat string */ const char *fmttype; /* Name in format file */

• /* Fetch functions */
• fetch_func_t fetch[FETCH_MTD_END];

-};

-struct fetch_param {

• fetch_func_t fn;
• void *data;

}; /* For defining macros, define string/string_size types */ @@ -154,66 +172,12 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(x64); DECLARE_BASIC_PRINT_TYPE_FUNC(string); -#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type

-/* Declare macro for basic types */ -#define DECLARE_FETCH_FUNC(method, type) \ -extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, \

• 			  void *data, void *dest)
  

-#define DECLARE_BASIC_FETCH_FUNCS(method) \ -DECLARE_FETCH_FUNC(method, u8); \ -DECLARE_FETCH_FUNC(method, u16); \ -DECLARE_FETCH_FUNC(method, u32); \ -DECLARE_FETCH_FUNC(method, u64)

-DECLARE_BASIC_FETCH_FUNCS(reg); -#define fetch_reg_string NULL -#define fetch_reg_string_size NULL

-DECLARE_BASIC_FETCH_FUNCS(retval); -#define fetch_retval_string NULL -#define fetch_retval_string_size NULL

-DECLARE_BASIC_FETCH_FUNCS(symbol); -DECLARE_FETCH_FUNC(symbol, string); -DECLARE_FETCH_FUNC(symbol, string_size);

-DECLARE_BASIC_FETCH_FUNCS(deref); -DECLARE_FETCH_FUNC(deref, string); -DECLARE_FETCH_FUNC(deref, string_size);

-DECLARE_BASIC_FETCH_FUNCS(bitfield); -#define fetch_bitfield_string NULL -#define fetch_bitfield_string_size NULL

-/* comm only makes sense as a string */ -#define fetch_comm_u8 NULL -#define fetch_comm_u16 NULL -#define fetch_comm_u32 NULL -#define fetch_comm_u64 NULL -DECLARE_FETCH_FUNC(comm, string); -DECLARE_FETCH_FUNC(comm, string_size);

-/*

• • Define macro for basic types - we don't need to define s* types, because
• • we have to care only about bitwidth at recording time.
• */

-#define DEFINE_BASIC_FETCH_FUNCS(method) \ -DEFINE_FETCH_##method(u8) \ -DEFINE_FETCH_##method(u16) \ -DEFINE_FETCH_##method(u32) \ -DEFINE_FETCH_##method(u64)

/* Default (unsigned long) fetch type */ #define __DEFAULT_FETCH_TYPE(t) x##t #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) -#define ASSIGN_FETCH_FUNC(method, type) \

• [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)

#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ {.name = _name, \ .size = _size, \ @@ -221,17 +185,6 @@ DEFINE_FETCH_##method(u64) .print = PRINT_TYPE_FUNC_NAME(ptype), \ .fmt = PRINT_TYPE_FMT_NAME(ptype), \ .fmttype = _fmttype, \

• .fetch = {					\
  

-ASSIGN_FETCH_FUNC(reg, ftype), \ -ASSIGN_FETCH_FUNC(stack, ftype), \ -ASSIGN_FETCH_FUNC(retval, ftype), \ -ASSIGN_FETCH_FUNC(comm, ftype), \ -ASSIGN_FETCH_FUNC(memory, ftype), \ -ASSIGN_FETCH_FUNC(symbol, ftype), \ -ASSIGN_FETCH_FUNC(deref, ftype), \ -ASSIGN_FETCH_FUNC(bitfield, ftype), \ -ASSIGN_FETCH_FUNC(file_offset, ftype), \

•  }						\
  

  }

#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ @@ -243,42 +196,10 @@ ASSIGN_FETCH_FUNC(file_offset, ftype), \ #define ASSIGN_FETCH_TYPE_END {} -#define FETCH_TYPE_STRING 0 -#define FETCH_TYPE_STRSIZE 1

#ifdef CONFIG_KPROBE_EVENTS -struct symbol_cache; -unsigned long update_symbol_cache(struct symbol_cache *sc); -void free_symbol_cache(struct symbol_cache *sc); -struct symbol_cache *alloc_symbol_cache(const char *sym, long offset); bool trace_kprobe_on_func_entry(struct trace_event_call *call); bool trace_kprobe_error_injectable(struct trace_event_call *call); #else -/* uprobes do not support symbol fetch methods */ -#define fetch_symbol_u8 NULL -#define fetch_symbol_u16 NULL -#define fetch_symbol_u32 NULL -#define fetch_symbol_u64 NULL -#define fetch_symbol_string NULL -#define fetch_symbol_string_size NULL

-struct symbol_cache { -}; -static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc) -{

• return 0;

-}

-static inline void __used free_symbol_cache(struct symbol_cache *sc) -{ -}

-static inline struct symbol_cache * __used -alloc_symbol_cache(const char *sym, long offset) -{

• return NULL;

-}

static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call) { return false; @@ -291,8 +212,8 @@ static inline bool trace_kprobe_error_injectable(struct trace_event_call *call) #endif /* CONFIG_KPROBE_EVENTS */ struct probe_arg {

• struct fetch_param fetch;
• struct fetch_param fetch_size;

• struct fetch_insn *code;
• bool dynamic;/* Dynamic array (string) is used */ unsigned int offset; /* Offset from argument entry */ const char *name; /* Name of this argument */ const char *comm; /* Command of this argument */

@@ -324,12 +245,6 @@ static inline bool trace_probe_is_registered(struct trace_probe *tp) return !!(tp->flags & TP_FLAG_REGISTERED); } -static nokprobe_inline void call_fetch(struct fetch_param *fprm,

• 		 struct pt_regs *regs, void *dest)
  

-{

• return fprm->fn(regs, fprm->data, dest);

-}

/* Check the name is good for event/group/fields */ static inline bool is_good_name(const char *name) { @@ -355,8 +270,7 @@ find_event_file_link(struct trace_probe *tp, struct trace_event_file *file) } extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,

•    struct probe_arg *parg, bool is_return, bool is_kprobe,
  

•    const struct fetch_type *ftbl);
  

•    struct probe_arg *parg, bool is_return, bool is_kprobe);
  

extern int traceprobe_conflict_field_name(const char *name, struct probe_arg *args, int narg); @@ -366,68 +280,6 @@ extern void traceprobe_free_probe_arg(struct probe_arg *arg); extern int traceprobe_split_symbol_offset(char *symbol, long *offset); -/* Sum up total data length for dynamic arraies (strings) */ -static nokprobe_inline int -__get_data_size(struct trace_probe *tp, struct pt_regs *regs) -{

• int i, ret = 0;
• u32 len;
• for (i = 0; i < tp->nr_args; i++)

• if (unlikely(tp->args[i].fetch_size.fn)) {
  

• 	call_fetch(&tp->args[i].fetch_size, regs, &len);
  

• 	ret += len;
  

• }
  

• return ret;

-}

-/* Store the value of each argument */ -static nokprobe_inline void -store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,

•  u8 *data, int maxlen)
  

-{

• int i;
• u32 end = tp->size;
• u32 *dl; /* Data (relative) location */
• for (i = 0; i < tp->nr_args; i++) {

• if (unlikely(tp->args[i].fetch_size.fn)) {
  

• 	/*
  

• 	 * First, we set the relative location and
  

• 	 * maximum data length to *dl
  

• 	 */
  

• 	dl = (u32 *)(data + tp->args[i].offset);
  

• 	*dl = make_data_rloc(maxlen, end - tp->args[i].offset);
  

• 	/* Then try to fetch string or dynamic array data */
  

• 	call_fetch(&tp->args[i].fetch, regs, dl);
  

• 	/* Reduce maximum length */
  

• 	end += get_rloc_len(*dl);
  

• 	maxlen -= get_rloc_len(*dl);
  

• 	/* Trick here, convert data_rloc to data_loc */
  

• 	*dl = convert_rloc_to_loc(*dl,
  

• 		 ent_size + tp->args[i].offset);
  

• } else
  

• 	/* Just fetching data normally */
  

• 	call_fetch(&tp->args[i].fetch, regs,
  

• 		   data + tp->args[i].offset);
  

• }

-}

-static inline int -print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args,

•  u8 *data, void *field)
  

-{

• int i;
• for (i = 0; i < nr_args; i++) {

• trace_seq_printf(s, " %s=", args[i].name);
  

• if (!args[i].type->print(s, data + args[i].offset, field))
  

• 	return -ENOMEM;
  

• }
• return 0;

-}

extern int set_print_fmt(struct trace_probe *tp, bool is_return); #ifdef CONFIG_PERF_EVENTS diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h new file mode 100644 index 000000000000..c8a5272abf01 --- /dev/null +++ b/kernel/trace/trace_probe_tmpl.h @@ -0,0 +1,120 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/*

• • Traceprobe fetch helper inlines
• */

+static nokprobe_inline void +fetch_store_raw(unsigned long val, struct fetch_insn *code, void *buf) +{

• switch (code->size) {
• case 1:

• *(u8 *)buf = (u8)val;
  

• break;
  

• case 2:

• *(u16 *)buf = (u16)val;
  

• break;
  

• case 4:

• *(u32 *)buf = (u32)val;
  

• break;
  

• case 8:

• //TBD: 32bit signed
  

• *(u64 *)buf = (u64)val;
  

• break;
  

• default:

• *(unsigned long *)buf = val;
  

• }

+}

+static nokprobe_inline void +fetch_apply_bitfield(struct fetch_insn *code, void *buf) +{

• switch (code->basesize) {
• case 1:

• *(u8 *)buf <<= code->lshift;
  

• *(u8 *)buf >>= code->rshift;
  

• break;
  

• case 2:

• *(u16 *)buf <<= code->lshift;
  

• *(u16 *)buf >>= code->rshift;
  

• break;
  

• case 4:

• *(u32 *)buf <<= code->lshift;
  

• *(u32 *)buf >>= code->rshift;
  

• break;
  

• case 8:

• *(u64 *)buf <<= code->lshift;
  

• *(u64 *)buf >>= code->rshift;
  

• break;
  

• }

+}

+/* Define this for each callsite */ +static int +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs,

•    void *dest, bool pre);
  

+/* Sum up total data length for dynamic arraies (strings) */ +static nokprobe_inline int +__get_data_size(struct trace_probe *tp, struct pt_regs *regs) +{

• struct probe_arg *arg;
• int i, ret = 0;
• u32 len;
• for (i = 0; i < tp->nr_args; i++) {

• arg = tp->args + i;
  

• if (unlikely(arg->dynamic)) {
  

• 	process_fetch_insn(arg->code, regs, &len, true);
  

• 	ret += len;
  

• }
  

• }
• return ret;

+}

+/* Store the value of each argument */ +static nokprobe_inline void +store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,

•  u8 *data, int maxlen)
  

+{

• struct probe_arg *arg;
• u32 end = tp->size;
• u32 *dl; /* Data (relative) location */
• int i;
• for (i = 0; i < tp->nr_args; i++) {

• arg = tp->args + i;
  

• if (unlikely(arg->dynamic)) {
  

• 	/*
  

• 	 * First, we set the relative location and
  

• 	 * maximum data length to *dl
  

• 	 */
  

• 	dl = (u32 *)(data + arg->offset);
  

• 	*dl = make_data_rloc(maxlen, end - arg->offset);
  

• 	/* Then try to fetch string or dynamic array data */
  

• 	process_fetch_insn(arg->code, regs, dl, false);
  

• 	/* Reduce maximum length */
  

• 	end += get_rloc_len(*dl);
  

• 	maxlen -= get_rloc_len(*dl);
  

• 	/* Trick here, convert data_rloc to data_loc */
  

• 	*dl = convert_rloc_to_loc(*dl, ent_size + arg->offset);
  

• } else
  

• 	/* Just fetching data normally */
  

• 	process_fetch_insn(arg->code, regs, data + arg->offset,
  

• 			   false);
  

• }

+}

+static inline int +print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args,

•  u8 *data, void *field)
  

+{

• int i;
• for (i = 0; i < nr_args; i++) {

• trace_seq_printf(s, " %s=", args[i].name);
  

• if (!args[i].type->print(s, data + args[i].offset, field))
  

• 	return -ENOMEM;
  

• }
• return 0;

+} diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 887da2bb63aa..9fc0123c721f 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -27,6 +27,7 @@ #include <linux/rculist.h> #include "trace_probe.h" +#include "trace_probe_tmpl.h" #define UPROBE_EVENT_SYSTEM "uprobes" @@ -109,37 +110,19 @@ static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) /*

• Uprobes-specific fetch functions

*/ -#define DEFINE_FETCH_stack(type) \ -static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \

• 			 void *offset, void *dest)	\
  

-{ \

• *(type *)dest = (type)get_user_stack_nth(regs, \

• 			      ((unsigned long)offset)); \
  

-} -DEFINE_BASIC_FETCH_FUNCS(stack) -/* No string on the stack entry */ -#define fetch_stack_string NULL -#define fetch_stack_string_size NULL

-#define DEFINE_FETCH_memory(type) \ -static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \

• 			  void *addr, void *dest)	\
  

-{ \

• type retval; \
• void __user *vaddr = (void __force __user *) addr; \

• 							\
  

• if (copy_from_user(&retval, vaddr, sizeof(type))) \

• *(type *)dest = 0;					\
  

• else \

• *(type *) dest = retval;				\
  

+static nokprobe_inline int +probe_user_read(void *dest, void *src, size_t size) +{

• void __user *vaddr = (void __force __user *)src;
• return copy_from_user(dest, vaddr, size);

} -DEFINE_BASIC_FETCH_FUNCS(memory) /*

• Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
• length and relative data location.

*/ -static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,

• 			    void *addr, void *dest)
  

+static nokprobe_inline void +fetch_store_string(unsigned long addr, void *dest) { long ret; u32 rloc = *(u32 *)dest; @@ -160,8 +143,9 @@ static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, } } -static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,

• 				 void *addr, void *dest)
  

+/* Return the length of string -- including null terminal byte */ +static nokprobe_inline void +fetch_store_strlen(unsigned long addr, void *dest) { int len; void __user *vaddr = (void __force __user *) addr; @@ -174,7 +158,7 @@ static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, *(u32 *)dest = len; } -static unsigned long translate_user_vaddr(void *file_offset) +static unsigned long translate_user_vaddr(unsigned long file_offset) { unsigned long base_addr; struct uprobe_dispatch_data *udd; @@ -182,44 +166,79 @@ static unsigned long translate_user_vaddr(void *file_offset) udd = (void *) current->utask->vaddr; base_addr = udd->bp_addr - udd->tu->offset;

• return base_addr + (unsigned long)file_offset;

• return base_addr + file_offset;

} -#define DEFINE_FETCH_file_offset(type) \ -static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \

• 			       void *offset, void *dest)\
  

-{ \

• void *vaddr = (void *)translate_user_vaddr(offset); \

• 							\
  

• FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \

+/* Note that we don't verify it, since the code does not come from user space */ +static int +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,

•    bool pre)
  

+{

• unsigned long val;
• int ret;
• /* 1st stage: get value from context */
• switch (code->op) {
• case FETCH_OP_REG:

• val = regs_get_register(regs, code->param);
  

• break;
  

• case FETCH_OP_STACK:

• val = get_user_stack_nth(regs, code->param);
  

• break;
  

• case FETCH_OP_STACKP:

• val = user_stack_pointer(regs);
  

• break;
  

• case FETCH_OP_RETVAL:

• val = regs_return_value(regs);
  

• break;
  

• case FETCH_OP_IMM:

• val = code->immediate;
  

• break;
  

• case FETCH_OP_FOFFS:

• val = translate_user_vaddr(code->immediate);
  

• break;
  

• default:

• return -EILSEQ;
  

• }
• code++;
• /* 2nd stage: dereference memory if needed */
• while (code->op == FETCH_OP_DEREF) {

• ret = probe_user_read(&val, (void *)val + code->offset,
  

• 		      sizeof(val));
  

• if (ret)
  

• 	return ret;
  

• code++;
  

• }
• /* 3rd stage: store value to buffer */
• switch (code->op) {
• case FETCH_OP_ST_RAW:

• fetch_store_raw(val, code, dest);
  

• break;
  

• case FETCH_OP_ST_MEM:

• probe_user_read(dest, (void *)val + code->offset, code->size);
  

• break;
  

• case FETCH_OP_ST_STRING:

• if (pre)
  

• 	fetch_store_strlen(val + code->offset, dest);
  

• else
  

• 	fetch_store_string(val + code->offset, dest);
  

• break;
  

• default:

• return -EILSEQ;
  

• }
• code++;
• /* 4th stage: modify stored value if needed */
• if (code->op == FETCH_OP_MOD_BF) {

• fetch_apply_bitfield(code, dest);
  

• code++;
  

• }
• return code->op == FETCH_OP_END ? 0 : -EILSEQ;

} -DEFINE_BASIC_FETCH_FUNCS(file_offset) -DEFINE_FETCH_file_offset(string) -DEFINE_FETCH_file_offset(string_size)

-/* Fetch type information table */ -static const struct fetch_type uprobes_fetch_type_table[] = {

• /* Special types */
• [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,

• 			sizeof(u32), 1, "__data_loc char[]"),
  

• [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,

• 			string_size, sizeof(u32), 0, "u32"),
  

• /* Basic types */
• ASSIGN_FETCH_TYPE(u8, u8, 0),
• ASSIGN_FETCH_TYPE(u16, u16, 0),
• ASSIGN_FETCH_TYPE(u32, u32, 0),
• ASSIGN_FETCH_TYPE(u64, u64, 0),
• ASSIGN_FETCH_TYPE(s8, u8, 1),
• ASSIGN_FETCH_TYPE(s16, u16, 1),
• ASSIGN_FETCH_TYPE(s32, u32, 1),
• ASSIGN_FETCH_TYPE(s64, u64, 1),
• ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
• ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
• ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
• ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
• ASSIGN_FETCH_TYPE_END

-}; +NOKPROBE_SYMBOL(process_fetch_insn) static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) { @@ -538,8 +557,7 @@ static int create_trace_uprobe(int argc, char **argv) /* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,

• 				 is_return, false,
  

• 				 uprobes_fetch_type_table);
  

• 				 is_return, false);
  

  if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error;

-- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html

On Fri, 23 Feb 2018 09:15:42 +0900 Namhyung Kim namhyung@kernel.org wrote:

Hi Masami,

On Thu, Feb 22, 2018 at 04:45:01PM +0900, Masami Hiramatsu wrote:

...

In Documentation/trace/kprobetrace.txt, it says

@SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)

However, the parser doesn't parse minus offset correctly, since commit 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") drops minus ("-") offset support for kprobe probe address usage.

This fixes the traceprobe_split_symbol_offset() to parse minus offset again with checking the offset range, and add a minus offset check in kprobe probe address usage.

Fixes: 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") Signed-off-by: Masami Hiramatsu mhiramat@kernel.org

---

Changes in v2.1:

• Fix to ensure the offset value is less than LONG_MAX.
• Fail if the offset is minus when traceprobe_split_symbol_offset() is used for the probe address.
• Add Fixes tag.

---

kernel/trace/trace_kprobe.c | 4 ++-- kernel/trace/trace_probe.c | 15 ++++++++++----- kernel/trace/trace_probe.h | 2 +- 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 5ce9b8cf7be3..b5b1d8aa47d6 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -667,7 +667,7 @@ static int create_trace_kprobe(int argc, char **argv) char *symbol = NULL, *event = NULL, *group = NULL; int maxactive = 0; char *arg;

• unsigned long offset = 0;

• long offset = 0; void *addr = NULL; char buf[MAX_EVENT_NAME_LEN];

@@ -755,7 +755,7 @@ static int create_trace_kprobe(int argc, char **argv) symbol = argv[1]; /* TODO: support .init module functions */ ret = traceprobe_split_symbol_offset(symbol, &offset);

• if (ret) {
  

• if (ret || offset < 0) {
  pr_info("Failed to parse either an address or a symbol.\n");
  return ret;
  

  }

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index d59357308677..ec3856147fdd 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -320,21 +320,26 @@ static fetch_func_t get_fetch_size_function(const struct fetch_type *type, } /* Split symbol and offset. */ -int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) +int traceprobe_split_symbol_offset(char *symbol, long *offset) {

• unsigned long ul; char *tmp; int ret;

if (!offset) return -EINVAL;

• tmp = strchr(symbol, '+');

• tmp = strpbrk(symbol, "+-"); if (tmp) {

• /* skip sign because kstrtoul doesn't accept '+' */
  

• ret = kstrtoul(tmp + 1, 0, offset);
  

• ret = kstrtoul(tmp + 1, 0, &ul);
  

Why not just using kstrtol() which handles the sign correctly?

Oops, right!

Thank you!

Thanks, Namhyung

...

if (ret)
	return ret;

• if (ul > LONG_MAX)
  

• 	return -E2BIG;
  

• if (*tmp == '-')
  

• 	*offset = -ul;
  

• else
  

• 	*offset = ul;
  

  *tmp = '\0'; } else *offset = 0;

diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 0745f895f780..75daff22ccea 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -365,7 +365,7 @@ extern int traceprobe_conflict_field_name(const char *name, extern void traceprobe_update_arg(struct probe_arg *arg); extern void traceprobe_free_probe_arg(struct probe_arg *arg); -extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); +extern int traceprobe_split_symbol_offset(char *symbol, long *offset); /* Sum up total data length for dynamic arraies (strings) */ static nokprobe_inline int