Commit-ID: c4861afe30aa3b00c95f9389f24cf6ede88416e4 Gitweb: http://git.kernel.org/tip/c4861afe30aa3b00c95f9389f24cf6ede88416e4 Author: Jiri Olsa <jolsa@xxxxxxxxxx> AuthorDate: Fri, 12 Oct 2012 13:02:21 +0200 Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> CommitDate: Wed, 7 Aug 2013 17:35:21 -0300 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@xxxxxxxxxx> Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Link: http://lkml.kernel.org/n/tip-e93pgyj20rqx48qzw10vj4r4@xxxxxxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> --- tools/perf/util/evlist.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index df77a44..10fcc03 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; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html