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Subject[PATCH V2 08/13] ftrace: Add perf text poke events for ftrace trampolines
Date
Add perf text poke events for ftrace trampolines when created and when
freed.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
arch/x86/kernel/ftrace.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 34e1dd495ce4..cec2ffae9e60 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -410,6 +410,8 @@ static void create_trampoline(struct ftrace_ops *ops)
ftrace_add_trampoline_to_kallsyms(ops);
perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, (u64)trampoline,
tramp_size, false, FTRACE_TRAMPOLINE_SYM);
+ /* Record the perf text poke event after the ksymbol register event */
+ perf_event_text_poke(trampoline, NULL, 0, trampoline, tramp_size);

set_vm_flush_reset_perms(trampoline);

@@ -537,6 +539,9 @@ void arch_ftrace_trampoline_free(struct ftrace_ops *ops)
if (!ops || !(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
return;

+ /* 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, (u64)ops->trampoline,
ops->trampoline_size, true, FTRACE_TRAMPOLINE_SYM);
/* Remove from kallsyms after the perf events */
--
2.17.1
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