| Message ID | 20230816154928.4171614-4-svens@linux.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | c4d6b5438116c184027b2e911c0f2c7c406fb47c |
| Headers | show |
| Series | few fixes for synthetic trace events | expand |
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 80a2a832f857..9897d0bfcab7 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -528,7 +528,8 @@ static notrace void trace_event_raw_event_synth(void *__data, str_val = (char *)(long)var_ref_vals[val_idx]; if (event->dynamic_fields[i]->is_stack) { - len = *((unsigned long *)str_val); + /* reserve one extra element for size */ + len = *((unsigned long *)str_val) + 1; len *= sizeof(unsigned long); } else { len = fetch_store_strlen((unsigned long)str_val);
While debugging another issue i noticed that the stack trace contains one invalid entry at the end: <idle>-0 [008] d..4. 26.484201: wake_lat: pid=0 delta=2629976084 000000009cc24024 stack=STACK: => __schedule+0xac6/0x1a98 => schedule+0x126/0x2c0 => schedule_timeout+0x150/0x2c0 => kcompactd+0x9ca/0xc20 => kthread+0x2f6/0x3d8 => __ret_from_fork+0x8a/0xe8 => 0x6b6b6b6b6b6b6b6b This is because the code failed to add the one element containing the number of entries to field_size. Fixes: 00cf3d672a9d ("tracing: Allow synthetic events to pass around stacktraces") Signed-off-by: Sven Schnelle <svens@linux.ibm.com> --- kernel/trace/trace_events_synth.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)