From: Sven Schnelle Date: Wed, 16 Aug 2023 15:49:28 +0000 (+0200) Subject: tracing/synthetic: Allocate one additional element for size X-Git-Tag: v6.6.17~4171^2~3 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c4d6b5438116c184027b2e911c0f2c7c406fb47c;p=platform%2Fkernel%2Flinux-rpi.git tracing/synthetic: Allocate one additional element for size While debugging another issue I noticed that the stack trace contains one invalid entry at the end: -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 Fixes: 00cf3d672a9d ("tracing: Allow synthetic events to pass around stacktraces") Signed-off-by: Sven Schnelle Signed-off-by: Steven Rostedt (Google) --- diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 80a2a83..9897d0b 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);