diff options
| author | Adrian Hunter <adrian.hunter@intel.com> | 2020-05-12 15:19:15 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-06-15 14:09:50 +0200 |
| commit | 548e1f6c76e1eb80ba29edd4286b9b9f2c37f5bf (patch) | |
| tree | 04890e877c028014798f9a7008de5377e7a2a81d /kernel/trace/ftrace.c | |
| parent | dd9ddf466ad7a5d2e247925d81ebb0b878bf3b76 (diff) | |
ftrace: Add perf text poke events for ftrace trampolines
Add perf text poke events for ftrace trampolines when created and when
freed.
There can be 3 text_poke events for ftrace trampolines:
1. NULL -> trampoline
By ftrace_update_trampoline() when !ops->trampoline
Trampoline created
2. [e.g. on x86] CALL rel32 -> CALL rel32
By arch_ftrace_update_trampoline() when ops->trampoline and
ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP
[e.g. on x86] via text_poke_bp() which generates text poke events
Trampoline-called function target updated
3. trampoline -> NULL
By ftrace_trampoline_free() when ops->trampoline and
ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP
Trampoline freed
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>
Link: https://lkml.kernel.org/r/20200512121922.8997-9-adrian.hunter@intel.com
Diffstat (limited to 'kernel/trace/ftrace.c')
| -rw-r--r-- | kernel/trace/ftrace.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 2baaf7716537..d6bba734ab72 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2791,6 +2791,13 @@ static void ftrace_trampoline_free(struct ftrace_ops *ops) { if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) && ops->trampoline) { + /* + * Record the text poke event before the ksymbol unregister + * event. + */ + perf_event_text_poke((void *)ops->trampoline, + (void *)ops->trampoline, + ops->trampoline_size, NULL, 0); perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, ops->trampoline, ops->trampoline_size, true, FTRACE_TRAMPOLINE_SYM); @@ -6816,6 +6823,13 @@ static void ftrace_update_trampoline(struct ftrace_ops *ops) perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, ops->trampoline, ops->trampoline_size, false, FTRACE_TRAMPOLINE_SYM); + /* + * Record the perf text poke event after the ksymbol register + * event. + */ + perf_event_text_poke((void *)ops->trampoline, NULL, 0, + (void *)ops->trampoline, + ops->trampoline_size); } } |