Add a selftest for PIDFD_INFO_EXIT behavior.

Link: https://lore.kernel.org/r/20250305-work-pidfs-kill_on_last_close-v3-16-c8c3d8361705@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

Add a selftest for PIDFD_INFO_EXIT behavior.

Link: https://lore.kernel.org/r/20250305-work-pidfs-kill_on_last_close-v3-10-c8c3d8361705@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

Link: https://lore.kernel.org/r/20241219-work-pidfs-mount-v1-2-dbc56198b839@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

Add selftests for pidfs file handles.

Link: https://lore.kernel.org/r/20241202-imstande-einsicht-d78753e1c632@brauner
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Use $(KHDR_INCLUDES) as lookup path for kernel headers. This prevents
building against kernel headers from the build environment in scenarios
where kernel headers are installed into a specific output directory
(O=...).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: <stable@vger.kernel.org> # 5.18+
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Fix warnings and enable Wall.

pidfd_wait.c: In function ‘wait_nonblock’:
pidfd_wait.c:150:13: warning: unused variable ‘status’ [-Wunused-variable]
  150 |  int pidfd, status = 0;
      |             ^~~~~~
...
pidfd_test.c: In function ‘child_poll_exec_test’:
pidfd_test.c:438:1: warning: no return statement in function returning non-void [-Wreturn-type]
  438 | }
      | ^

Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
v2: fix mistake assignment to pidfd
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

This is basically a test-suite for setns() and as of now contains:
- test that we can't pass garbage flags
- test that we can't attach to the namespaces of  task that has already exited
- test that we can incrementally setns into all namespaces of a target task
  using a pidfd
- test that we can setns atomically into all namespaces of a target task
- test that we can't cross setns into a user namespace outside of our user
  namespace hierarchy
- test that we can't setns into namespaces owned by user namespaces over which
  we are not privileged

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200505140432.181565-4-christian.brauner@ubuntu.com

The following tests:
  * Fetch FD, and then compare via kcmp
  * Make sure getfd can be blocked by blocking ptrace_may_access
  * Making sure fetching bad FDs fails
  * Make sure trying to set flags to non-zero results in an EINVAL

Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200107175927.4558-5-sargun@sargun.me
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Add a test that checks that if pid namespaces are configured the fdinfo
file of a pidfd contains an NSpid: entry containing the process id in
the current and additionally all nested namespaces. In the case that
a pidfd is from a pid namespace not in the same namespace hierarchy as
the process accessing the fdinfo file, ensure the 'NSpid' shows 0 for
that pidfd, analogous to the 'Pid' entry.

Signed-off-by: Christian Kellner <christian@kellner.me>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20191014162034.2185-2-ckellner@redhat.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

Fix build failure:

undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status

Fix CFLAGS to include pthread correctly.

Fixes: 740378dc7834 ("pidfd: add polling selftests")
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190924195237.30519-1-skhan@linuxfoundation.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>