diff options
| author | Dmitry V. Levin <ldv@altlinux.org> | 2019-06-23 13:28:00 +0200 |
|---|---|---|
| committer | Christian Brauner <christian@brauner.io> | 2019-06-24 15:55:50 +0200 |
| commit | bee19cd8f241ab3cd1bf79e03884e5371f9ef514 (patch) | |
| tree | 49430f9d17dcbc8c1d47b1cd5b15426a5ec6ba0d /samples/pidfd | |
| parent | fork: don't check parent_tidptr with CLONE_PIDFD (diff) | |
| download | linux-bee19cd8f241ab3cd1bf79e03884e5371f9ef514.tar.xz linux-bee19cd8f241ab3cd1bf79e03884e5371f9ef514.zip | |
samples: make pidfd-metadata fail gracefully on older kernels
Initialize pidfd to an invalid descriptor, to fail gracefully on
those kernels that do not implement CLONE_PIDFD and leave pidfd
unchanged.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Christian Brauner <christian@brauner.io>
Diffstat (limited to 'samples/pidfd')
| -rw-r--r-- | samples/pidfd/pidfd-metadata.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/samples/pidfd/pidfd-metadata.c b/samples/pidfd/pidfd-metadata.c index 14b454448429..c459155daf9a 100644 --- a/samples/pidfd/pidfd-metadata.c +++ b/samples/pidfd/pidfd-metadata.c @@ -83,7 +83,7 @@ static int pidfd_metadata_fd(pid_t pid, int pidfd) int main(int argc, char *argv[]) { - int pidfd = 0, ret = EXIT_FAILURE; + int pidfd = -1, ret = EXIT_FAILURE; char buf[4096] = { 0 }; pid_t pid; int procfd, statusfd; @@ -91,7 +91,11 @@ int main(int argc, char *argv[]) pid = pidfd_clone(CLONE_PIDFD, &pidfd); if (pid < 0) - exit(ret); + err(ret, "CLONE_PIDFD"); + if (pidfd == -1) { + warnx("CLONE_PIDFD is not supported by the kernel"); + goto out; + } procfd = pidfd_metadata_fd(pid, pidfd); close(pidfd); |