[PATCH AUTOSEL 5.10 040/100] drm/vkms: fix misuse of WARN_ON
From: Sasha Levin <sashal@kernel.org>
Date: 2021-05-03 16:49:57
Also in:
dri-devel, lkml
Subsystem:
drm driver for virtual kernel modesetting (vkms), drm drivers, drm drivers and misc gpu patches, the rest · Maintainers:
Louis Chauvet, David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Linus Torvalds
From: Dmitry Vyukov <dvyukov@google.com> [ Upstream commit b4142fc4d52d051d4d8df1fb6c569e5b445d369e ] vkms_vblank_simulate() uses WARN_ON for timing-dependent condition (timer overrun). This is a mis-use of WARN_ON, WARN_ON must be used to denote kernel bugs. Use pr_warn() instead. Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: syzbot+4fc21a003c8332eb0bdd@syzkaller.appspotmail.com Cc: Rodrigo Siqueira <redacted> Cc: Melissa Wen <melissa.srw@gmail.com> Cc: Haneen Mohammed <hamohammed.sa@gmail.com> Cc: Daniel Vetter <redacted> Cc: David Airlie <redacted> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Acked-by: Melissa Wen <melissa.srw@gmail.com> Signed-off-by: Melissa Wen <melissa.srw@gmail.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210320132840.1315853-1-dvyukov@google.com Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/gpu/drm/vkms/vkms_crtc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c
index 09c012d54d58..1ae5cd47d954 100644
--- a/drivers/gpu/drm/vkms/vkms_crtc.c
+++ b/drivers/gpu/drm/vkms/vkms_crtc.c@@ -18,7 +18,8 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer) ret_overrun = hrtimer_forward_now(&output->vblank_hrtimer, output->period_ns); - WARN_ON(ret_overrun != 1); + if (ret_overrun != 1) + pr_warn("%s: vblank timer overrun\n", __func__); spin_lock(&output->lock); ret = drm_crtc_handle_vblank(crtc);
--
2.30.2