From: Namhyung Kim namhyung@kernel.org
[ Upstream commit 999e4eaa4b3691acf85d094836260ec4b66c74fd ]
It needs to enter the namespace before reading a file.
Fixes: 4183a8d70a288627 ("perf tools: Allow synthesizing the build id for kernel/modules/tasks in PERF_RECORD_MMAP2") Signed-off-by: Namhyung Kim namhyung@kernel.org Cc: Adrian Hunter adrian.hunter@intel.com Cc: Ian Rogers irogers@google.com Cc: Jiri Olsa jolsa@kernel.org Cc: Peter Zijlstra peterz@infradead.org Link: http://lore.kernel.org/lkml/20220920222822.2171056-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/synthetic-events.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c index 84d17bd4efae..64e273b2b1b2 100644 --- a/tools/perf/util/synthetic-events.c +++ b/tools/perf/util/synthetic-events.c @@ -367,13 +367,24 @@ static void perf_record_mmap2__read_build_id(struct perf_record_mmap2 *event, bool is_kernel) { struct build_id bid; + struct nsinfo *nsi; + struct nscookie nc; int rc;
- if (is_kernel) + if (is_kernel) { rc = sysfs__read_build_id("/sys/kernel/notes", &bid); - else - rc = filename__read_build_id(event->filename, &bid) > 0 ? 0 : -1; + goto out; + } + + nsi = nsinfo__new(event->pid); + nsinfo__mountns_enter(nsi, &nc);
+ rc = filename__read_build_id(event->filename, &bid) > 0 ? 0 : -1; + + nsinfo__mountns_exit(&nc); + nsinfo__put(nsi); + +out: if (rc == 0) { memcpy(event->build_id, bid.data, sizeof(bid.data)); event->build_id_size = (u8) bid.size;