From: Arnaldo Carvalho de Melo Date: Wed, 10 Jun 2026 23:16:02 +0000 (-0300) Subject: perf dso: Set error code when open() fails on uncompressed fallback path X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d2c6069d68ee9d53b05fe38bc2049cc4286fbb16;p=thirdparty%2Flinux.git perf dso: Set error code when open() fails on uncompressed fallback path filename__decompress() has an early return for files that are not actually compressed, where it calls open() directly. When open() fails, the function returns -1 but never sets *err. The caller chain (decompress_kmodule → dso__decompress_kmodule_path → dso__get_filename) then reads *dso__load_errno(dso) to set errno, but that field was never populated, so errno gets a stale or zero value. With errno=0, __open_dso() computes fd = -errno = 0, which is non- negative, so callers treat fd 0 (stdin) as a valid DSO file descriptor. Set *err = errno when open() fails on the uncompressed path, matching the error handling on the compressed path at line 354. Reported-by: sashiko-bot Fixes: 8b42b7e5e8b5692b ("perf tools: Add is_compressed callback to compressions array") Cc: Jiri Olsa Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index 511921bd901d8..1a2fc6d18da74 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -344,9 +344,12 @@ int filename__decompress(const char *name, char *pathname, * descriptor to the uncompressed file. */ if (!compressions[comp].is_compressed(name)) { + fd = open(name, O_RDONLY | O_CLOEXEC); + if (fd < 0) + *err = errno; if (pathname && len > 0) pathname[0] = '\0'; - return open(name, O_RDONLY | O_CLOEXEC); + return fd; } fd = mkostemp(tmpbuf, O_CLOEXEC);