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/symbol.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'tools/perf/util/symbol.c') diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index e816e4220d33..3fed54de5401 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -1869,14 +1869,14 @@ int dso__load(struct dso *dso, struct map *map) /* * Read the build id if possible. This is required for - * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work + * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work. Don't block in case path + * isn't for a regular file. */ - if (!dso__has_build_id(dso) && - is_regular_file(dso__long_name(dso))) { + if (!dso__has_build_id(dso)) { struct build_id bid = { .size = 0, }; __symbol__join_symfs(name, PATH_MAX, dso__long_name(dso)); - if (filename__read_build_id(name, &bid) > 0) + if (filename__read_build_id(name, &bid, /*block=*/false) > 0) dso__set_build_id(dso, &bid); } -- cgit v1.2.3