lib: Avoid assertion if sig_ioctl is unsed from a child accidentally

The timer is tied to the creator thread, i.e. it is not inheritable
across fork() or clone()/pthread_create(). Using it thus causes an
assertion failure in the test after the one that aborts (and so on until
we perform an interruptible test correctly) - one mistake snowballs. We
can stop the snowball by doing an initial check and diverting back to
drmIoctl().

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/igt_aux.c b/lib/igt_aux.c
index 91f3c4eb62ee..c32569f1e890 100644
--- a/lib/igt_aux.c
+++ b/lib/igt_aux.c
@@ -115,6 +115,12 @@ sig_ioctl(int fd, unsigned long request, void *arg)
 	SIG_ASSERT(__igt_sigiter.tid == gettid());
 
 	memset(&its, 0, sizeof(its));
+	if (timer_settime(__igt_sigiter.timer, 0, &its, NULL)) {
+		/* oops, we didn't undo the interrupter (i.e. !unwound abort) */
+		igt_ioctl = drmIoctl;
+		return drmIoctl(fd, request, arg);
+	}
+
 	its.it_value = __igt_sigiter.offset;
 	do {
 		long serial;