perf_evlist__mmap_ex() can fail without setting errno (for example, fail in condition checking. In this case all syscall is success). If this happen, record__open() incorrectly returns 0. Force setting rc is a quick way to avoid this problem, or we have to follow all possible code path in perf_evlist__mmap_ex() to make sure there's at least one system call before returning an error.
Signed-off-by: Wang Nan <[email protected]> Signed-off-by: He Kuang <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Zefan Li <[email protected]> Cc: [email protected] --- tools/perf/builtin-record.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index a2de15b..fa16099 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -363,7 +363,10 @@ try_again: } else { pr_err("failed to mmap with %d (%s)\n", errno, strerror_r(errno, msg, sizeof(msg))); - rc = -errno; + if (errno) + rc = -errno; + else + rc = -EINVAL; } goto out; } -- 1.8.3.4
