Hi Colin, On Sat, 19 Jan 2013 16:36:54 +0000, Colin King wrote: > From: Colin Ian King <colin.k...@canonical.com> > > __perf_evsel__read_on_cpu() only bails out with -ENOMEM if > evsel->counts is NULL and perf_evsel__alloc_counts() has returned > an error. If perf_evsel__alloc_counts() does not return an error > we get an NULL pointer deference on evsel->counts->cpu[cpu] > if evsel->counts is NULL.
perf_evsel__alloc_counts() should allocate evsel->counts when it sees evsel->counts is NULL and return negative error code if the allocation fails. So I don't see any problem in current code. With your code, it won't try to allocate if ->counts is NULL but overwrite existing ->counts? Thanks, Namhyung > > Signed-off-by: Colin Ian King <colin.k...@canonical.com> > --- > tools/perf/util/evsel.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c > index 1b16dd1..93acd06 100644 > --- a/tools/perf/util/evsel.c > +++ b/tools/perf/util/evsel.c > @@ -640,7 +640,7 @@ int __perf_evsel__read_on_cpu(struct perf_evsel *evsel, > if (FD(evsel, cpu, thread) < 0) > return -EINVAL; > > - if (evsel->counts == NULL && perf_evsel__alloc_counts(evsel, cpu + 1) < > 0) > + if (evsel->counts == NULL || perf_evsel__alloc_counts(evsel, cpu + 1) < > 0) > return -ENOMEM; > > if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) < 0) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
