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author | Oleg Nesterov <oleg@redhat.com> | 2013-06-17 19:02:11 +0200 |
---|---|---|
committer | Steven Rostedt <rostedt@goodmis.org> | 2013-07-19 03:31:28 +0200 |
commit | cd92bf61d6d70bd3eb33b46d600e3f3eb9c5778a (patch) | |
tree | 7f02ec47e54b3fa2a139a21bbcfed90318de79d3 /kernel/trace/trace_event_perf.c | |
parent | tracing/syscall: Avoid perf_trace_buf_*() if sys_data->perf_events is empty (diff) | |
download | linux-cd92bf61d6d70bd3eb33b46d600e3f3eb9c5778a.tar.xz linux-cd92bf61d6d70bd3eb33b46d600e3f3eb9c5778a.zip |
tracing/perf: Move the PERF_MAX_TRACE_SIZE check into perf_trace_buf_prepare()
Every perf_trace_buf_prepare() caller does
WARN_ONCE(size > PERF_MAX_TRACE_SIZE, message) and "message" is
almost the same.
Shift this WARN_ONCE() into perf_trace_buf_prepare(). This changes
the meaning of _ONCE, but I think this is fine.
- 4947014 2932448 10104832 17984294 1126b26 vmlinux
+ 4948422 2932448 10104832 17985702 11270a6 vmlinux
on my build.
Link: http://lkml.kernel.org/r/20130617170211.GA19813@redhat.com
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_event_perf.c')
-rw-r--r-- | kernel/trace/trace_event_perf.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 12df5573086e..80c36bcf66e8 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -236,6 +236,10 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type, BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long)); + if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, + "perf buffer not large enough")) + return NULL; + pc = preempt_count(); *rctxp = perf_swevent_get_recursion_context(); |