QEMU, when started with "-device isa-debug-exit -no-reboot" will exit with status code 2N+1 when N is written to 0x501. This is particularly convenient for automated tests but this is not portable. As such we only enable this on x86_64 when pid==1. In addition, this requires an ioperm() call but in order not to have to define arch-specific syscalls we just perform the syscall by hand there.
Signed-off-by: Willy Tarreau w@1wt.eu --- tools/testing/selftests/nolibc/nolibc-test.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index 5f2173610d03..45793b6f2244 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -638,6 +638,15 @@ int main(int argc, char **argv, char **envp) printf("Leaving init with final status: %d\n", !!ret); if (ret == 0) reboot(LINUX_REBOOT_CMD_POWER_OFF); +#if defined(__x86_64__) + /* QEMU started with "-device isa-debug-exit -no-reboot" will + * exit with status code 2N+1 when N is written to 0x501. We + * hard-code the syscall here as it's arch-dependent. + */ + else if (my_syscall3(__NR_ioperm, 0x501, 1, 1) == 0) + asm volatile ("outb %%al, %%dx" :: "d"(0x501), "a"(0)); + /* if it does nothing, fall back to the regular panic */ +#endif }
printf("Exiting with status %d\n", !!ret);