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authorJiri Olsa <jolsa@redhat.com>2012-10-12 13:02:21 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2013-08-07 17:35:21 -0300
commitc4861afe30aa3b00c95f9389f24cf6ede88416e4 (patch)
tree03533a832810cece7d2eac4d076ad32fd5e4e716 /tools/perf/util/evlist.c
parent9ede473cc9f655f8a10cfc8ebbf04c48d84db7ee (diff)
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perf evlist: Fix event ID retrieval for group format read case
We need to fail the event ID retrieval in case both following conditions are true: - we are on kernel with no PERF_EVENT_IOC_ID support - PERF_FORMAT_GROUP read format is set The PERF_FORMAT_GROUP read format bit is the killer for retrieving event ID out of the read syscall, because we have no guarantee of the event placement within leader kernel sibling list. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-e93pgyj20rqx48qzw10vj4r4@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/evlist.c')
-rw-r--r--tools/perf/util/evlist.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index df77a44fe276..10fcc0372aa9 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -314,6 +314,13 @@ static int perf_evlist__id_add_fd(struct perf_evlist *evlist,
/* Legacy way to get event id.. All hail to old kernels! */
+ /*
+ * This way does not work with group format read, so bail
+ * out in that case.
+ */
+ if (perf_evlist__read_format(evlist) & PERF_FORMAT_GROUP)
+ return -1;
+
if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
read(fd, &read_data, sizeof(read_data)) == -1)
return -1;