diff options
| author | Tom Zanussi <zanussi@kernel.org> | 2023-02-10 15:33:03 -0600 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2023-02-15 19:59:09 -0500 |
| commit | fc1a9dc101292403babe0c5c2f99f4748580ed98 (patch) | |
| tree | 0483ad668866fb6f5d2f58690b1d08733153afe7 /kernel/trace/trace_events_synth.c | |
| parent | 9c1c251d670bc107b9ce600a2c20adb08b4849e9 (diff) | |
tracing/histogram: Don't use strlen to find length of stacktrace variables
Because stacktraces are saved in dynamic strings,
trace_event_raw_event_synth() uses strlen to determine the length of
the stack. Stacktraces may contain 0-bytes, though, in the saved
addresses, so the length found and passed to reserve() will be too
small.
Fix this by using the first unsigned long in the stack variables to
store the actual number of elements in the stack and have
trace_event_raw_event_synth() use that to determine the length of the
stack.
Link: https://lkml.kernel.org/r/1ed6906cd9d6477ef2bd8e63c61de20a9ffe64d7.1676063532.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_events_synth.c')
| -rw-r--r-- | kernel/trace/trace_events_synth.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 306c89e0ce55..70bddb25d9c0 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -538,7 +538,12 @@ static notrace void trace_event_raw_event_synth(void *__data, val_idx = var_ref_idx[field_pos]; str_val = (char *)(long)var_ref_vals[val_idx]; - len = kern_fetch_store_strlen((unsigned long)str_val); + if (event->dynamic_fields[i]->is_stack) { + len = *((unsigned long *)str_val); + len *= sizeof(unsigned long); + } else { + len = kern_fetch_store_strlen((unsigned long)str_val); + } fields_size += len; } |