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authorVineet Gupta <Vineet.Gupta1@synopsys.com>2015-01-13 19:13:23 +0530
committerArnaldo Carvalho de Melo <acme@redhat.com>2015-01-28 12:43:32 -0300
commit8d9cbd8f870e1aab00fb0f8a465887877a1d6f82 (patch)
tree35b4f3b3dd3cad7e0bc55290ac7b3204c49ba2c8 /tools/perf
parentb3890e4704594fa23abe1395d1fafc97d3214be8 (diff)
downloadlinux-8d9cbd8f870e1aab00fb0f8a465887877a1d6f82.tar.bz2
perf evsel: Don't rely on malloc working for sz 0
When running perf on ARC (uClibc based userspace), ran into this issue ------------->8---------------- [ARCLinux]$ ./perf record ls bin etc perf sys debug init perf.data tmp [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.001 MB perf.data (~24 samples) ] [ARCLinux]$ ./perf report incompatible file format (rerun with -v to learn more) ------------->8---------------- The problem happens in the following call stack when zalloc is called with size zero glibc default / uClibc with MALLOC_GLIBC_COMPAT are OK, but not if that config option is not enabled. cmd_report perf_session__new perf_session__open perf_session__read_header read_attr(fd, header, &f_attr) nr_ids = f_attr.ids.size / sizeof(u64); <-- 0 perf_evsel__alloc_id(vsel, 1, nr_ids) zalloc(ncpus * nthreads * sizeof(u64)) <-- 0 header.c: read_attr() (gdb) p *f_attr $17 = { attr = { type = 0, size = 96, config = 0, { sample_period = 4000, sample_freq = 4000 }, ... ids = { offset = 104, size = 0 <------ } } Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Suggested-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexey Brodkin <Alexey.Brodkin@synopsys.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1421156604-30603-5-git-send-email-vgupta@synopsys.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
-rw-r--r--tools/perf/util/evsel.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 1e90c8557ede..1d826d63bc20 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -797,6 +797,9 @@ int perf_evsel__enable(struct perf_evsel *evsel, int ncpus, int nthreads)
int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
{
+ if (ncpus == 0 || nthreads == 0)
+ return 0;
+
if (evsel->system_wide)
nthreads = 1;