6.4-stable review patch. If anyone has any objections, please let me know.
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From: Sven Schnelle svens@linux.ibm.com
[ Upstream commit c4d6b5438116c184027b2e911c0f2c7c406fb47c ]
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.
Link: https://lkml.kernel.org/r/20230816154928.4171614-4-svens@linux.ibm.com
Cc: Masami Hiramatsu mhiramat@kernel.org Fixes: 00cf3d672a9d ("tracing: Allow synthetic events to pass around stacktraces") Signed-off-by: Sven Schnelle svens@linux.ibm.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/trace/trace_events_synth.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index a4c58a932dfa6..32109d092b10f 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);