Messages in this thread Patch in this message | | | From | Frederic Weisbecker <> | Subject | [PATCH 1/3] perfcounter: Initialize tracepoint record before any use | Date | Sat, 8 Aug 2009 04:26:35 +0200 |
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Despite that the tracepoint record is always present when the PERF_SAMPLE_TP_RECORD flag is set, gcc whines, thinking it might not be initialized:
kernel/perf_counter.c: In function ‘perf_counter_output’: kernel/perf_counter.c:2650: warning: ‘tp’ may be used uninitialized in this function
Then, initialize it to NULL and always check if it's not NULL before dereference it.
Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> --- kernel/perf_counter.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 142ae5a..a6963e2 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -2647,7 +2647,7 @@ void perf_counter_output(struct perf_counter *counter, int nmi, u64 counter; } group_entry; struct perf_callchain_entry *callchain = NULL; - struct perf_tracepoint_record *tp; + struct perf_tracepoint_record *tp = NULL; int callchain_size = 0; u64 time; struct { @@ -2718,7 +2718,8 @@ void perf_counter_output(struct perf_counter *counter, int nmi, if (sample_type & PERF_SAMPLE_TP_RECORD) { tp = data->private; - header.size += tp->size; + if (tp) + header.size += tp->size; } ret = perf_output_begin(&handle, counter, header.size, nmi, 1); @@ -2784,7 +2785,7 @@ void perf_counter_output(struct perf_counter *counter, int nmi, } } - if (sample_type & PERF_SAMPLE_TP_RECORD) + if ((sample_type & PERF_SAMPLE_TP_RECORD) && tp) perf_output_copy(&handle, tp->record, tp->size); perf_output_end(&handle); -- 1.6.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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