[PATCH 08/17] selftests/nolibc: exit with poweroff on success when getpid() == 1

Willy Tarreau
2022-07-19T21:47:29Z

The idea is to ease automated testing under qemu. If the test succeeds
while running as PID 1, indicating the system was booted with init=/test,
let's just power off so that qemu can exit with a successful code. In
other situations it will exit and provoke a panic, which may be caught
for example with CONFIG_PVPANIC.

Signed-off-by: Willy Tarreau <w@1wt.eu>
---
tools/testing/selftests/nolibc/nolibc-test.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index ab7c4cbdef9b..5f2173610d03 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -626,6 +626,20 @@ int main(int argc, char **argv, char **envp)
}

printf("Total number of errors: %d\n", ret);
+
+ if (getpid() == 1) {
+ /* we're running as init, there's no other process on the
+ * system, thus likely started from a VM for a quick check.
+ * Exiting will provoke a kernel panic that may be reported
+ * as an error by Qemu or the hypervisor, while stopping
+ * cleanly will often be reported as a success. This allows
+ * to use the output of this program for bisecting kernels.
+ */
+ printf("Leaving init with final status: %d\n", !!ret);
+ if (ret == 0)
+ reboot(LINUX_REBOOT_CMD_POWER_OFF);
+ }
+
printf("Exiting with status %d\n", !!ret);
return !!ret;
}
--
2.17.5