From 2c369d91d0933aaff96b6b807b22363e6a38a625 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Fri, 22 Aug 2025 17:00:24 -0700 Subject: perf symbol: Add blocking argument to filename__read_build_id When synthesizing build-ids, for build ID mmap2 events, they will be added for data mmaps if -d/--data is specified. The files opened for their build IDs may block on the open causing perf to hang during synthesis. There is some robustness in existing calls to filename__read_build_id by checking the file path is to a regular file, which unfortunately fails for symlinks. Rather than adding more is_regular_file calls, switch filename__read_build_id to take a "block" argument and specify O_NONBLOCK when this is false. The existing is_regular_file checking callers and the event synthesis callers are made to pass false and thereby avoiding the hang. Fixes: 53b00ff358dc ("perf record: Make --buildid-mmap the default") Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250823000024.724394-3-irogers@google.com Signed-off-by: Namhyung Kim --- tools/perf/util/build-id.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'tools/perf/util/build-id.c') diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c index a7018a3b0437..bf7f3268b9a2 100644 --- a/tools/perf/util/build-id.c +++ b/tools/perf/util/build-id.c @@ -115,7 +115,7 @@ int filename__snprintf_build_id(const char *pathname, char *sbuild_id, size_t sb struct build_id bid = { .size = 0, }; int ret; - ret = filename__read_build_id(pathname, &bid); + ret = filename__read_build_id(pathname, &bid, /*block=*/true); if (ret < 0) return ret; @@ -841,7 +841,7 @@ static int filename__read_build_id_ns(const char *filename, int ret; nsinfo__mountns_enter(nsi, &nsc); - ret = filename__read_build_id(filename, bid); + ret = filename__read_build_id(filename, bid, /*block=*/true); nsinfo__mountns_exit(&nsc); return ret; -- cgit v1.2.3