[PATCH 1/2] selftests: riscv: vstate_exec_nolibc: Check the return value of waitpid()

[Danish Khateeb <danishkhateeb03@gmail.com>]

vstate_exec_nolibc does not check whether waitpid() succeeds, so status
is used uninitialized if it fails. Since nolibc implements waitpid() on
top of waitid(), GCC can see this, and warns:

  vstate_exec_nolibc.c:78:12: warning: 'status' may be used uninitialized [-Wmaybe-uninitialized]

Fail if waitpid() fails, as launch_test() does for the same call.

Fixes: 7cf6198ce22d ("selftests: Test RISC-V Vector prctl interface")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202609250003.hvssJlRZ-lkp@intel.com/
Assisted-by: LLM
Signed-off-by: Danish Khateeb <danishkhateeb03@gmail.com>
---
 tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c b/tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c
index 12f1b1b1c7aa..5f53e5e8ac52 100644
--- a/tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c
+++ b/tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c
@@ -69,6 +69,10 @@ int main(int argc, char **argv)
 	}
 
 	rc = waitpid(-1, &status, 0);
+	if (rc == -1) {
+		puts("waitpid failed\n");
+		exit(-1);
+	}
 
 	if (WIFEXITED(status) && WEXITSTATUS(status) == -1) {
 		puts("child exited abnormally\n");
-- 
2.55.0