Patch "selftests: fixup build warnings in pidfd / clone3 tests" has been added to the 5.16-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    selftests: fixup build warnings in pidfd / clone3 tests

to the 5.16-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     selftests-fixup-build-warnings-in-pidfd-clone3-tests.patch
and it can be found in the queue-5.16 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit e24b19429a02047169cb6e117fddf28d6648fb69
Author: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Date:   Thu Jan 27 14:11:15 2022 -0800

    selftests: fixup build warnings in pidfd / clone3 tests
    
    [ Upstream commit e2aa5e650b07693477dff554053605976789fd68 ]
    
    These are some trivial fixups, which were needed to build the tests with
    clang and -Werror. The following issues are fixed:
    
    - Remove various unused variables.
    - In child_poll_leader_exit_test, clang isn't smart enough to realize
      syscall(SYS_exit, 0) won't return, so it complains we never return
      from a non-void function. Add an extra exit(0) to appease it.
    - In test_pidfd_poll_leader_exit, ret may be branched on despite being
      uninitialized, if we have !use_waitpid. Initialize it to zero to get
      the right behavior in that case.
    
    Signed-off-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
    Acked-by: Christian Brauner <brauner@xxxxxxxxxx>
    Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
index 076cf4325f783..cd4582129c7d6 100644
--- a/tools/testing/selftests/clone3/clone3.c
+++ b/tools/testing/selftests/clone3/clone3.c
@@ -126,8 +126,6 @@ static void test_clone3(uint64_t flags, size_t size, int expected,
 
 int main(int argc, char *argv[])
 {
-	pid_t pid;
-
 	uid_t uid = getuid();
 
 	ksft_print_header();
diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c
index 529eb700ac26a..9a2d64901d591 100644
--- a/tools/testing/selftests/pidfd/pidfd_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_test.c
@@ -441,7 +441,6 @@ static void test_pidfd_poll_exec(int use_waitpid)
 {
 	int pid, pidfd = 0;
 	int status, ret;
-	pthread_t t1;
 	time_t prog_start = time(NULL);
 	const char *test_name = "pidfd_poll check for premature notification on child thread exec";
 
@@ -500,13 +499,14 @@ static int child_poll_leader_exit_test(void *args)
 	 */
 	*child_exit_secs = time(NULL);
 	syscall(SYS_exit, 0);
+	/* Never reached, but appeases compiler thinking we should return. */
+	exit(0);
 }
 
 static void test_pidfd_poll_leader_exit(int use_waitpid)
 {
 	int pid, pidfd = 0;
-	int status, ret;
-	time_t prog_start = time(NULL);
+	int status, ret = 0;
 	const char *test_name = "pidfd_poll check for premature notification on non-empty"
 				"group leader exit";
 
diff --git a/tools/testing/selftests/pidfd/pidfd_wait.c b/tools/testing/selftests/pidfd/pidfd_wait.c
index be2943f072f60..17999e082aa71 100644
--- a/tools/testing/selftests/pidfd/pidfd_wait.c
+++ b/tools/testing/selftests/pidfd/pidfd_wait.c
@@ -39,7 +39,7 @@ static int sys_waitid(int which, pid_t pid, siginfo_t *info, int options,
 
 TEST(wait_simple)
 {
-	int pidfd = -1, status = 0;
+	int pidfd = -1;
 	pid_t parent_tid = -1;
 	struct clone_args args = {
 		.parent_tid = ptr_to_u64(&parent_tid),
@@ -47,7 +47,6 @@ TEST(wait_simple)
 		.flags = CLONE_PIDFD | CLONE_PARENT_SETTID,
 		.exit_signal = SIGCHLD,
 	};
-	int ret;
 	pid_t pid;
 	siginfo_t info = {
 		.si_signo = 0,
@@ -88,7 +87,7 @@ TEST(wait_simple)
 
 TEST(wait_states)
 {
-	int pidfd = -1, status = 0;
+	int pidfd = -1;
 	pid_t parent_tid = -1;
 	struct clone_args args = {
 		.parent_tid = ptr_to_u64(&parent_tid),