5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sandipan Das sandipan.das@amd.com
[ Upstream commit 4462fbfe6ec1bfe2196b977010f6ce7b43a32f2c ]
Commit 3e702ff6d1ea ("perf/x86: Add LBR software filter support for Intel CPUs") introduces a software branch filter which complements the hardware branch filter and adds an x86 branch classifier.
Move the branch classifier to arch/x86/events/ so that it can be utilized by other vendors for branch record filtering.
Signed-off-by: Sandipan Das sandipan.das@amd.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Link: https://lore.kernel.org/r/bae5b95470d6bd49f40954bd379f414f5afcb965.166021139... Stable-dep-of: e53899771a02 ("perf/x86/lbr: Filter vsyscall addresses") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/events/Makefile | 2 +- arch/x86/events/intel/lbr.c | 273 ----------------------------------- arch/x86/events/perf_event.h | 62 ++++++++ arch/x86/events/utils.c | 216 +++++++++++++++++++++++++++ 4 files changed, 279 insertions(+), 274 deletions(-) create mode 100644 arch/x86/events/utils.c
diff --git a/arch/x86/events/Makefile b/arch/x86/events/Makefile index 9933c0e8e97a9..86a76efa8bb6d 100644 --- a/arch/x86/events/Makefile +++ b/arch/x86/events/Makefile @@ -1,5 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only -obj-y += core.o probe.o +obj-y += core.o probe.o utils.o obj-$(CONFIG_PERF_EVENTS_INTEL_RAPL) += rapl.o obj-y += amd/ obj-$(CONFIG_X86_LOCAL_APIC) += msr.o diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c index bc3e40184719f..e8c6575cf65ea 100644 --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -4,7 +4,6 @@
#include <asm/perf_event.h> #include <asm/msr.h> -#include <asm/insn.h>
#include "../perf_event.h"
@@ -73,65 +72,6 @@ static const enum {
#define LBR_FROM_SIGNEXT_2MSB (BIT_ULL(60) | BIT_ULL(59))
-/* - * x86control flow change classification - * x86control flow changes include branches, interrupts, traps, faults - */ -enum { - X86_BR_NONE = 0, /* unknown */ - - X86_BR_USER = 1 << 0, /* branch target is user */ - X86_BR_KERNEL = 1 << 1, /* branch target is kernel */ - - X86_BR_CALL = 1 << 2, /* call */ - X86_BR_RET = 1 << 3, /* return */ - X86_BR_SYSCALL = 1 << 4, /* syscall */ - X86_BR_SYSRET = 1 << 5, /* syscall return */ - X86_BR_INT = 1 << 6, /* sw interrupt */ - X86_BR_IRET = 1 << 7, /* return from interrupt */ - X86_BR_JCC = 1 << 8, /* conditional */ - X86_BR_JMP = 1 << 9, /* jump */ - X86_BR_IRQ = 1 << 10,/* hw interrupt or trap or fault */ - X86_BR_IND_CALL = 1 << 11,/* indirect calls */ - X86_BR_ABORT = 1 << 12,/* transaction abort */ - X86_BR_IN_TX = 1 << 13,/* in transaction */ - X86_BR_NO_TX = 1 << 14,/* not in transaction */ - X86_BR_ZERO_CALL = 1 << 15,/* zero length call */ - X86_BR_CALL_STACK = 1 << 16,/* call stack */ - X86_BR_IND_JMP = 1 << 17,/* indirect jump */ - - X86_BR_TYPE_SAVE = 1 << 18,/* indicate to save branch type */ - -}; - -#define X86_BR_PLM (X86_BR_USER | X86_BR_KERNEL) -#define X86_BR_ANYTX (X86_BR_NO_TX | X86_BR_IN_TX) - -#define X86_BR_ANY \ - (X86_BR_CALL |\ - X86_BR_RET |\ - X86_BR_SYSCALL |\ - X86_BR_SYSRET |\ - X86_BR_INT |\ - X86_BR_IRET |\ - X86_BR_JCC |\ - X86_BR_JMP |\ - X86_BR_IRQ |\ - X86_BR_ABORT |\ - X86_BR_IND_CALL |\ - X86_BR_IND_JMP |\ - X86_BR_ZERO_CALL) - -#define X86_BR_ALL (X86_BR_PLM | X86_BR_ANY) - -#define X86_BR_ANY_CALL \ - (X86_BR_CALL |\ - X86_BR_IND_CALL |\ - X86_BR_ZERO_CALL |\ - X86_BR_SYSCALL |\ - X86_BR_IRQ |\ - X86_BR_INT) - /* * Intel LBR_CTL bits * @@ -1168,219 +1108,6 @@ int intel_pmu_setup_lbr_filter(struct perf_event *event) return ret; }
-/* - * return the type of control flow change at address "from" - * instruction is not necessarily a branch (in case of interrupt). - * - * The branch type returned also includes the priv level of the - * target of the control flow change (X86_BR_USER, X86_BR_KERNEL). - * - * If a branch type is unknown OR the instruction cannot be - * decoded (e.g., text page not present), then X86_BR_NONE is - * returned. - */ -static int branch_type(unsigned long from, unsigned long to, int abort) -{ - struct insn insn; - void *addr; - int bytes_read, bytes_left; - int ret = X86_BR_NONE; - int ext, to_plm, from_plm; - u8 buf[MAX_INSN_SIZE]; - int is64 = 0; - - to_plm = kernel_ip(to) ? X86_BR_KERNEL : X86_BR_USER; - from_plm = kernel_ip(from) ? X86_BR_KERNEL : X86_BR_USER; - - /* - * maybe zero if lbr did not fill up after a reset by the time - * we get a PMU interrupt - */ - if (from == 0 || to == 0) - return X86_BR_NONE; - - if (abort) - return X86_BR_ABORT | to_plm; - - if (from_plm == X86_BR_USER) { - /* - * can happen if measuring at the user level only - * and we interrupt in a kernel thread, e.g., idle. - */ - if (!current->mm) - return X86_BR_NONE; - - /* may fail if text not present */ - bytes_left = copy_from_user_nmi(buf, (void __user *)from, - MAX_INSN_SIZE); - bytes_read = MAX_INSN_SIZE - bytes_left; - if (!bytes_read) - return X86_BR_NONE; - - addr = buf; - } else { - /* - * The LBR logs any address in the IP, even if the IP just - * faulted. This means userspace can control the from address. - * Ensure we don't blindly read any address by validating it is - * a known text address. - */ - if (kernel_text_address(from)) { - addr = (void *)from; - /* - * Assume we can get the maximum possible size - * when grabbing kernel data. This is not - * _strictly_ true since we could possibly be - * executing up next to a memory hole, but - * it is very unlikely to be a problem. - */ - bytes_read = MAX_INSN_SIZE; - } else { - return X86_BR_NONE; - } - } - - /* - * decoder needs to know the ABI especially - * on 64-bit systems running 32-bit apps - */ -#ifdef CONFIG_X86_64 - is64 = kernel_ip((unsigned long)addr) || any_64bit_mode(current_pt_regs()); -#endif - insn_init(&insn, addr, bytes_read, is64); - if (insn_get_opcode(&insn)) - return X86_BR_ABORT; - - switch (insn.opcode.bytes[0]) { - case 0xf: - switch (insn.opcode.bytes[1]) { - case 0x05: /* syscall */ - case 0x34: /* sysenter */ - ret = X86_BR_SYSCALL; - break; - case 0x07: /* sysret */ - case 0x35: /* sysexit */ - ret = X86_BR_SYSRET; - break; - case 0x80 ... 0x8f: /* conditional */ - ret = X86_BR_JCC; - break; - default: - ret = X86_BR_NONE; - } - break; - case 0x70 ... 0x7f: /* conditional */ - ret = X86_BR_JCC; - break; - case 0xc2: /* near ret */ - case 0xc3: /* near ret */ - case 0xca: /* far ret */ - case 0xcb: /* far ret */ - ret = X86_BR_RET; - break; - case 0xcf: /* iret */ - ret = X86_BR_IRET; - break; - case 0xcc ... 0xce: /* int */ - ret = X86_BR_INT; - break; - case 0xe8: /* call near rel */ - if (insn_get_immediate(&insn) || insn.immediate1.value == 0) { - /* zero length call */ - ret = X86_BR_ZERO_CALL; - break; - } - fallthrough; - case 0x9a: /* call far absolute */ - ret = X86_BR_CALL; - break; - case 0xe0 ... 0xe3: /* loop jmp */ - ret = X86_BR_JCC; - break; - case 0xe9 ... 0xeb: /* jmp */ - ret = X86_BR_JMP; - break; - case 0xff: /* call near absolute, call far absolute ind */ - if (insn_get_modrm(&insn)) - return X86_BR_ABORT; - - ext = (insn.modrm.bytes[0] >> 3) & 0x7; - switch (ext) { - case 2: /* near ind call */ - case 3: /* far ind call */ - ret = X86_BR_IND_CALL; - break; - case 4: - case 5: - ret = X86_BR_IND_JMP; - break; - } - break; - default: - ret = X86_BR_NONE; - } - /* - * interrupts, traps, faults (and thus ring transition) may - * occur on any instructions. Thus, to classify them correctly, - * we need to first look at the from and to priv levels. If they - * are different and to is in the kernel, then it indicates - * a ring transition. If the from instruction is not a ring - * transition instr (syscall, systenter, int), then it means - * it was a irq, trap or fault. - * - * we have no way of detecting kernel to kernel faults. - */ - if (from_plm == X86_BR_USER && to_plm == X86_BR_KERNEL - && ret != X86_BR_SYSCALL && ret != X86_BR_INT) - ret = X86_BR_IRQ; - - /* - * branch priv level determined by target as - * is done by HW when LBR_SELECT is implemented - */ - if (ret != X86_BR_NONE) - ret |= to_plm; - - return ret; -} - -#define X86_BR_TYPE_MAP_MAX 16 - -static int branch_map[X86_BR_TYPE_MAP_MAX] = { - PERF_BR_CALL, /* X86_BR_CALL */ - PERF_BR_RET, /* X86_BR_RET */ - PERF_BR_SYSCALL, /* X86_BR_SYSCALL */ - PERF_BR_SYSRET, /* X86_BR_SYSRET */ - PERF_BR_UNKNOWN, /* X86_BR_INT */ - PERF_BR_ERET, /* X86_BR_IRET */ - PERF_BR_COND, /* X86_BR_JCC */ - PERF_BR_UNCOND, /* X86_BR_JMP */ - PERF_BR_IRQ, /* X86_BR_IRQ */ - PERF_BR_IND_CALL, /* X86_BR_IND_CALL */ - PERF_BR_UNKNOWN, /* X86_BR_ABORT */ - PERF_BR_UNKNOWN, /* X86_BR_IN_TX */ - PERF_BR_UNKNOWN, /* X86_BR_NO_TX */ - PERF_BR_CALL, /* X86_BR_ZERO_CALL */ - PERF_BR_UNKNOWN, /* X86_BR_CALL_STACK */ - PERF_BR_IND, /* X86_BR_IND_JMP */ -}; - -static int -common_branch_type(int type) -{ - int i; - - type >>= 2; /* skip X86_BR_USER and X86_BR_KERNEL */ - - if (type) { - i = __ffs(type); - if (i < X86_BR_TYPE_MAP_MAX) - return branch_map[i]; - } - - return PERF_BR_UNKNOWN; -} - enum { ARCH_LBR_BR_TYPE_JCC = 0, ARCH_LBR_BR_TYPE_NEAR_IND_JMP = 1, diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h index e3ac05c97b5e5..9b4d51c0e0ad4 100644 --- a/arch/x86/events/perf_event.h +++ b/arch/x86/events/perf_event.h @@ -1181,6 +1181,68 @@ static inline void set_linear_ip(struct pt_regs *regs, unsigned long ip) regs->ip = ip; }
+/* + * x86control flow change classification + * x86control flow changes include branches, interrupts, traps, faults + */ +enum { + X86_BR_NONE = 0, /* unknown */ + + X86_BR_USER = 1 << 0, /* branch target is user */ + X86_BR_KERNEL = 1 << 1, /* branch target is kernel */ + + X86_BR_CALL = 1 << 2, /* call */ + X86_BR_RET = 1 << 3, /* return */ + X86_BR_SYSCALL = 1 << 4, /* syscall */ + X86_BR_SYSRET = 1 << 5, /* syscall return */ + X86_BR_INT = 1 << 6, /* sw interrupt */ + X86_BR_IRET = 1 << 7, /* return from interrupt */ + X86_BR_JCC = 1 << 8, /* conditional */ + X86_BR_JMP = 1 << 9, /* jump */ + X86_BR_IRQ = 1 << 10,/* hw interrupt or trap or fault */ + X86_BR_IND_CALL = 1 << 11,/* indirect calls */ + X86_BR_ABORT = 1 << 12,/* transaction abort */ + X86_BR_IN_TX = 1 << 13,/* in transaction */ + X86_BR_NO_TX = 1 << 14,/* not in transaction */ + X86_BR_ZERO_CALL = 1 << 15,/* zero length call */ + X86_BR_CALL_STACK = 1 << 16,/* call stack */ + X86_BR_IND_JMP = 1 << 17,/* indirect jump */ + + X86_BR_TYPE_SAVE = 1 << 18,/* indicate to save branch type */ + +}; + +#define X86_BR_PLM (X86_BR_USER | X86_BR_KERNEL) +#define X86_BR_ANYTX (X86_BR_NO_TX | X86_BR_IN_TX) + +#define X86_BR_ANY \ + (X86_BR_CALL |\ + X86_BR_RET |\ + X86_BR_SYSCALL |\ + X86_BR_SYSRET |\ + X86_BR_INT |\ + X86_BR_IRET |\ + X86_BR_JCC |\ + X86_BR_JMP |\ + X86_BR_IRQ |\ + X86_BR_ABORT |\ + X86_BR_IND_CALL |\ + X86_BR_IND_JMP |\ + X86_BR_ZERO_CALL) + +#define X86_BR_ALL (X86_BR_PLM | X86_BR_ANY) + +#define X86_BR_ANY_CALL \ + (X86_BR_CALL |\ + X86_BR_IND_CALL |\ + X86_BR_ZERO_CALL |\ + X86_BR_SYSCALL |\ + X86_BR_IRQ |\ + X86_BR_INT) + +int common_branch_type(int type); +int branch_type(unsigned long from, unsigned long to, int abort); + ssize_t x86_event_sysfs_show(char *page, u64 config, u64 event); ssize_t intel_event_sysfs_show(char *page, u64 config);
diff --git a/arch/x86/events/utils.c b/arch/x86/events/utils.c new file mode 100644 index 0000000000000..a32368945462f --- /dev/null +++ b/arch/x86/events/utils.c @@ -0,0 +1,216 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <asm/insn.h> + +#include "perf_event.h" + +/* + * return the type of control flow change at address "from" + * instruction is not necessarily a branch (in case of interrupt). + * + * The branch type returned also includes the priv level of the + * target of the control flow change (X86_BR_USER, X86_BR_KERNEL). + * + * If a branch type is unknown OR the instruction cannot be + * decoded (e.g., text page not present), then X86_BR_NONE is + * returned. + */ +int branch_type(unsigned long from, unsigned long to, int abort) +{ + struct insn insn; + void *addr; + int bytes_read, bytes_left; + int ret = X86_BR_NONE; + int ext, to_plm, from_plm; + u8 buf[MAX_INSN_SIZE]; + int is64 = 0; + + to_plm = kernel_ip(to) ? X86_BR_KERNEL : X86_BR_USER; + from_plm = kernel_ip(from) ? X86_BR_KERNEL : X86_BR_USER; + + /* + * maybe zero if lbr did not fill up after a reset by the time + * we get a PMU interrupt + */ + if (from == 0 || to == 0) + return X86_BR_NONE; + + if (abort) + return X86_BR_ABORT | to_plm; + + if (from_plm == X86_BR_USER) { + /* + * can happen if measuring at the user level only + * and we interrupt in a kernel thread, e.g., idle. + */ + if (!current->mm) + return X86_BR_NONE; + + /* may fail if text not present */ + bytes_left = copy_from_user_nmi(buf, (void __user *)from, + MAX_INSN_SIZE); + bytes_read = MAX_INSN_SIZE - bytes_left; + if (!bytes_read) + return X86_BR_NONE; + + addr = buf; + } else { + /* + * The LBR logs any address in the IP, even if the IP just + * faulted. This means userspace can control the from address. + * Ensure we don't blindly read any address by validating it is + * a known text address. + */ + if (kernel_text_address(from)) { + addr = (void *)from; + /* + * Assume we can get the maximum possible size + * when grabbing kernel data. This is not + * _strictly_ true since we could possibly be + * executing up next to a memory hole, but + * it is very unlikely to be a problem. + */ + bytes_read = MAX_INSN_SIZE; + } else { + return X86_BR_NONE; + } + } + + /* + * decoder needs to know the ABI especially + * on 64-bit systems running 32-bit apps + */ +#ifdef CONFIG_X86_64 + is64 = kernel_ip((unsigned long)addr) || any_64bit_mode(current_pt_regs()); +#endif + insn_init(&insn, addr, bytes_read, is64); + if (insn_get_opcode(&insn)) + return X86_BR_ABORT; + + switch (insn.opcode.bytes[0]) { + case 0xf: + switch (insn.opcode.bytes[1]) { + case 0x05: /* syscall */ + case 0x34: /* sysenter */ + ret = X86_BR_SYSCALL; + break; + case 0x07: /* sysret */ + case 0x35: /* sysexit */ + ret = X86_BR_SYSRET; + break; + case 0x80 ... 0x8f: /* conditional */ + ret = X86_BR_JCC; + break; + default: + ret = X86_BR_NONE; + } + break; + case 0x70 ... 0x7f: /* conditional */ + ret = X86_BR_JCC; + break; + case 0xc2: /* near ret */ + case 0xc3: /* near ret */ + case 0xca: /* far ret */ + case 0xcb: /* far ret */ + ret = X86_BR_RET; + break; + case 0xcf: /* iret */ + ret = X86_BR_IRET; + break; + case 0xcc ... 0xce: /* int */ + ret = X86_BR_INT; + break; + case 0xe8: /* call near rel */ + if (insn_get_immediate(&insn) || insn.immediate1.value == 0) { + /* zero length call */ + ret = X86_BR_ZERO_CALL; + break; + } + fallthrough; + case 0x9a: /* call far absolute */ + ret = X86_BR_CALL; + break; + case 0xe0 ... 0xe3: /* loop jmp */ + ret = X86_BR_JCC; + break; + case 0xe9 ... 0xeb: /* jmp */ + ret = X86_BR_JMP; + break; + case 0xff: /* call near absolute, call far absolute ind */ + if (insn_get_modrm(&insn)) + return X86_BR_ABORT; + + ext = (insn.modrm.bytes[0] >> 3) & 0x7; + switch (ext) { + case 2: /* near ind call */ + case 3: /* far ind call */ + ret = X86_BR_IND_CALL; + break; + case 4: + case 5: + ret = X86_BR_IND_JMP; + break; + } + break; + default: + ret = X86_BR_NONE; + } + /* + * interrupts, traps, faults (and thus ring transition) may + * occur on any instructions. Thus, to classify them correctly, + * we need to first look at the from and to priv levels. If they + * are different and to is in the kernel, then it indicates + * a ring transition. If the from instruction is not a ring + * transition instr (syscall, systenter, int), then it means + * it was a irq, trap or fault. + * + * we have no way of detecting kernel to kernel faults. + */ + if (from_plm == X86_BR_USER && to_plm == X86_BR_KERNEL + && ret != X86_BR_SYSCALL && ret != X86_BR_INT) + ret = X86_BR_IRQ; + + /* + * branch priv level determined by target as + * is done by HW when LBR_SELECT is implemented + */ + if (ret != X86_BR_NONE) + ret |= to_plm; + + return ret; +} + +#define X86_BR_TYPE_MAP_MAX 16 + +static int branch_map[X86_BR_TYPE_MAP_MAX] = { + PERF_BR_CALL, /* X86_BR_CALL */ + PERF_BR_RET, /* X86_BR_RET */ + PERF_BR_SYSCALL, /* X86_BR_SYSCALL */ + PERF_BR_SYSRET, /* X86_BR_SYSRET */ + PERF_BR_UNKNOWN, /* X86_BR_INT */ + PERF_BR_ERET, /* X86_BR_IRET */ + PERF_BR_COND, /* X86_BR_JCC */ + PERF_BR_UNCOND, /* X86_BR_JMP */ + PERF_BR_IRQ, /* X86_BR_IRQ */ + PERF_BR_IND_CALL, /* X86_BR_IND_CALL */ + PERF_BR_UNKNOWN, /* X86_BR_ABORT */ + PERF_BR_UNKNOWN, /* X86_BR_IN_TX */ + PERF_BR_UNKNOWN, /* X86_BR_NO_TX */ + PERF_BR_CALL, /* X86_BR_ZERO_CALL */ + PERF_BR_UNKNOWN, /* X86_BR_CALL_STACK */ + PERF_BR_IND, /* X86_BR_IND_JMP */ +}; + +int common_branch_type(int type) +{ + int i; + + type >>= 2; /* skip X86_BR_USER and X86_BR_KERNEL */ + + if (type) { + i = __ffs(type); + if (i < X86_BR_TYPE_MAP_MAX) + return branch_map[i]; + } + + return PERF_BR_UNKNOWN; +}