From: Dmitry Vyukov <dvyukov@google.com>
To: daniel@ffwll.ch, airlied@linux.ie, hamohammed.sa@gmail.com,
melissa.srw@gmail.com, rodrigosiqueiramelo@gmail.com
Cc: syzbot+4fc21a003c8332eb0bdd@syzkaller.appspotmail.com,
dri-devel@lists.freedesktop.org,
Dmitry Vyukov <dvyukov@google.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH] drm/vkms: fix misuse of WARN_ON
Date: Sat, 20 Mar 2021 14:28:40 +0100 [thread overview]
Message-ID: <20210320132840.1315853-1-dvyukov@google.com> (raw)
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 <rodrigosiqueiramelo@gmail.com>
Cc: Melissa Wen <melissa.srw@gmail.com>
Cc: Haneen Mohammed <hamohammed.sa@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Change-Id: I7f01c288092bc7e472ec63af198f93ce3d8c49f7
---
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 0443b7deeaef6..758d8a98d96b3 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);
base-commit: e94c55b8e0a0bbe9a026250cf31e2fa45957d776
--
2.31.0.291.g576ba9dcdaf-goog
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next reply other threads:[~2021-03-20 13:28 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-20 13:28 Dmitry Vyukov [this message]
2021-03-24 22:00 ` [PATCH] drm/vkms: fix misuse of WARN_ON Melissa Wen
2021-03-25 6:48 ` Dmitry Vyukov
2021-03-25 11:55 ` Melissa Wen
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