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 <wangn...@huawei.com> Signed-off-by: He Kuang <heku...@huawei.com> Cc: Arnaldo Carvalho de Melo <a...@redhat.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Zefan Li <lize...@huawei.com> Cc: pi3or...@163.com --- 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