[PATCH V4 08/13] ftrace: Add perf text poke events for ftrace trampolines

Adrian Hunter
2020-03-04T09:07:57Z

Add perf text poke events for ftrace trampolines when created and when
freed.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
kernel/trace/ftrace.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index fda0c9144642..75f9aac31fec 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2795,6 +2795,13 @@ 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);
@@ -6812,6 +6819,13 @@ 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);
}
}

--
2.17.1