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| author | Steven Rostedt <srostedt@redhat.com> | 2011-01-14 19:25:58 +0300 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2011-01-14 19:25:58 +0300 |
| commit | c94fbe1d9e1e9b1a1f82eb0b53b1cf53bcf9712b (patch) | |
| tree | 0191c752be8ea739136106f6cca95df61cffc676 /include/trace | |
| parent | 4ad9f594d7199c99f6b1b3ef88c64bd5920a4592 (diff) | |
| download | linux-c94fbe1d9e1e9b1a1f82eb0b53b1cf53bcf9712b.tar.xz | |
tracing: Only process module tracepoints once
The commit:
9f987b3141f086de27832514aad9f50a53f754
tracing: Include module.h in define_trace.h
only solved half the problem. If the trace/events/module.h header is
included at the time of define_trace.h (or in ftrace.h within it),
the module.h TRACE_SYSTEM will override the current TRACE_SYSTEM
macro.
Since define_trace.h is included when CREATE_TRACE_POINTS is set,
and the first thing it does is to #undef CREATE_TRACE_POINTS,
by placing the module.h TRACE_SYSTEM inside a
#ifdef CREATE_TRACE_POINTS
we can prevent it from overriding the TRACE_SYSTEM that is
being processed, and still process the module.h tracepoints
when the module code defines CREATE_TRACE_POINTS and includes
the trace/events/module.h header.
As with commit 9f987b3141, this is only an issue if module.h
is not included before the trace/events/<event>.h file is
included, which (luckily) has not happened yet.
Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include/trace')
| -rw-r--r-- | include/trace/events/module.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/trace/events/module.h b/include/trace/events/module.h index c7bb2f0482fe..c6bae36547e5 100644 --- a/include/trace/events/module.h +++ b/include/trace/events/module.h @@ -1,5 +1,15 @@ +/* + * Because linux/module.h has tracepoints in the header, and ftrace.h + * eventually includes this file, define_trace.h includes linux/module.h + * But we do not want the module.h to override the TRACE_SYSTEM macro + * variable that define_trace.h is processing, so we only set it + * when module events are being processed, which would happen when + * CREATE_TRACE_POINTS is defined. + */ +#ifdef CREATE_TRACE_POINTS #undef TRACE_SYSTEM #define TRACE_SYSTEM module +#endif #if !defined(_TRACE_MODULE_H) || defined(TRACE_HEADER_MULTI_READ) #define _TRACE_MODULE_H |