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author | Adrian Hunter <adrian.hunter@intel.com> | 2020-05-12 15:19:12 +0300 |
---|---|---|
committer | Peter Zijlstra <peterz@infradead.org> | 2020-06-15 14:09:49 +0200 |
commit | 3e46bb40af8c12947c093efb8af56e0e921cd39b (patch) | |
tree | 368afd1f003f6f75ab49c2d1c21146304205eb6f /arch/x86/kernel/kprobes/core.c | |
parent | 69e49088692899d25dedfa22f00dfb9761e86ed7 (diff) | |
download | linux-3e46bb40af8c12947c093efb8af56e0e921cd39b.tar.bz2 |
perf/x86: Add perf text poke events for kprobes
Add perf text poke events for kprobes. That includes:
- the replaced instruction(s) which are executed out-of-line
i.e. arch_copy_kprobe() and arch_remove_kprobe()
- the INT3 that activates the kprobe
i.e. arch_arm_kprobe() and arch_disarm_kprobe()
- optimised kprobe function
i.e. arch_prepare_optimized_kprobe() and
__arch_remove_optimized_kprobe()
- optimised kprobe
i.e. arch_optimize_kprobes() and arch_unoptimize_kprobe()
Resulting in 8 possible text_poke events:
0: NULL -> probe.ainsn.insn (if ainsn.boostable && !kp.post_handler)
arch_copy_kprobe()
1: old0 -> INT3 arch_arm_kprobe()
// boosted kprobe active
2: NULL -> optprobe_trampoline arch_prepare_optimized_kprobe()
3: INT3,old1,old2,old3,old4 -> JMP32 arch_optimize_kprobes()
// optprobe active
4: JMP32 -> INT3,old1,old2,old3,old4
// optprobe disabled and kprobe active (this sometimes goes back to 3)
arch_unoptimize_kprobe()
5: optprobe_trampoline -> NULL arch_remove_optimized_kprobe()
// boosted kprobe active
6: INT3 -> old0 arch_disarm_kprobe()
7: probe.ainsn.insn -> NULL (if ainsn.boostable && !kp.post_handler)
arch_remove_kprobe()
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20200512121922.8997-6-adrian.hunter@intel.com
Diffstat (limited to 'arch/x86/kernel/kprobes/core.c')
-rw-r--r-- | arch/x86/kernel/kprobes/core.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 3bafe1bd4dc7..bcc53c0d17c1 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -33,6 +33,7 @@ #include <linux/hardirq.h> #include <linux/preempt.h> #include <linux/sched/debug.h> +#include <linux/perf_event.h> #include <linux/extable.h> #include <linux/kdebug.h> #include <linux/kallsyms.h> @@ -471,6 +472,9 @@ static int arch_copy_kprobe(struct kprobe *p) /* Also, displacement change doesn't affect the first byte */ p->opcode = buf[0]; + p->ainsn.tp_len = len; + perf_event_text_poke(p->ainsn.insn, NULL, 0, buf, len); + /* OK, write back the instruction(s) into ROX insn buffer */ text_poke(p->ainsn.insn, buf, len); @@ -502,12 +506,18 @@ int arch_prepare_kprobe(struct kprobe *p) void arch_arm_kprobe(struct kprobe *p) { - text_poke(p->addr, ((unsigned char []){INT3_INSN_OPCODE}), 1); + u8 int3 = INT3_INSN_OPCODE; + + text_poke(p->addr, &int3, 1); text_poke_sync(); + perf_event_text_poke(p->addr, &p->opcode, 1, &int3, 1); } void arch_disarm_kprobe(struct kprobe *p) { + u8 int3 = INT3_INSN_OPCODE; + + perf_event_text_poke(p->addr, &int3, 1, &p->opcode, 1); text_poke(p->addr, &p->opcode, 1); text_poke_sync(); } @@ -515,6 +525,9 @@ void arch_disarm_kprobe(struct kprobe *p) void arch_remove_kprobe(struct kprobe *p) { if (p->ainsn.insn) { + /* Record the perf event before freeing the slot */ + perf_event_text_poke(p->ainsn.insn, p->ainsn.insn, + p->ainsn.tp_len, NULL, 0); free_insn_slot(p->ainsn.insn, p->ainsn.boostable); p->ainsn.insn = NULL; } |