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| author | Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> | 2023-07-03 07:28:53 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-07-23 13:49:24 +0200 |
| commit | f92a82dc486a539e2888b403ab18cf3963eb5b4d (patch) | |
| tree | 2c2e0b909b9aa64fa6d7cbdf8a0b21440530fb5d /kernel | |
| parent | 7772d5c44011aaf7035ff86b5881e89e7765c49f (diff) | |
| download | linux-f92a82dc486a539e2888b403ab18cf3963eb5b4d.tar.gz | |
kernel/trace: Fix cleanup logic of enable_trace_eprobe
[ Upstream commit cf0a624dc706c306294c14e6b3e7694702f25191 ]
The enable_trace_eprobe() function enables all event probes, attached
to given trace probe. If an error occurs in enabling one of the event
probes, all others should be roll backed. There is a bug in that roll
back logic - instead of all event probes, only the failed one is
disabled.
Link: https://lore.kernel.org/all/20230703042853.1427493-1-tz.stoyanov@gmail.com/
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_eprobe.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 753fc536525d..d2370cdb4c1d 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -743,6 +743,7 @@ static int enable_trace_eprobe(struct trace_event_call *call, struct trace_eprobe *ep; bool enabled; int ret = 0; + int cnt = 0; tp = trace_probe_primary_from_call(call); if (WARN_ON_ONCE(!tp)) @@ -766,12 +767,25 @@ static int enable_trace_eprobe(struct trace_event_call *call, if (ret) break; enabled = true; + cnt++; } if (ret) { /* Failed to enable one of them. Roll back all */ - if (enabled) - disable_eprobe(ep, file->tr); + if (enabled) { + /* + * It's a bug if one failed for something other than memory + * not being available but another eprobe succeeded. + */ + WARN_ON_ONCE(ret != -ENOMEM); + + list_for_each_entry(pos, trace_probe_probe_list(tp), list) { + ep = container_of(pos, struct trace_eprobe, tp); + disable_eprobe(ep, file->tr); + if (!--cnt) + break; + } + } if (file) trace_probe_remove_file(tp, file); else |