Messages in this thread | | | Subject | Re: [PATCH 18/28] drm: avoid uninitialized timestamp use in wait_vblank | From | Mario Kleiner <> | Date | Tue, 18 Oct 2016 01:47:24 +0200 |
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On 10/18/2016 12:13 AM, Arnd Bergmann wrote: > gcc warns about the timestamp in drm_wait_vblank being possibly > used without an initialization: > > drivers/gpu/drm/drm_irq.c: In function 'drm_crtc_send_vblank_event': > drivers/gpu/drm/drm_irq.c:992:24: error: 'now.tv_usec' may be used uninitialized in this function [-Werror=maybe-uninitialized] > drivers/gpu/drm/drm_irq.c:1069:17: note: 'now.tv_usec' was declared here > drivers/gpu/drm/drm_irq.c:991:23: error: 'now.tv_sec' may be used uninitialized in this function [-Werror=maybe-uninitialized] > > This can happen if drm_vblank_count_and_time() returns 0 in its > error path. To sanitize the error case, I'm changing that function > to return a zero timestamp when it fails. > > Fixes: e6ae8687a87b ("drm: idiot-proof vblank") > Reviewed-by: David Herrmann <dh.herrmann@gmail.com> > Cc: Rob Clark <robdclark@gmail.com> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > First submitted in January 2016, second submission in February, > the patch is still required. > > drivers/gpu/drm/drm_irq.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c > index b969a64..48a6167 100644 > --- a/drivers/gpu/drm/drm_irq.c > +++ b/drivers/gpu/drm/drm_irq.c > @@ -952,8 +952,10 @@ static u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe, > u32 vblank_count; > unsigned int seq; > > - if (WARN_ON(pipe >= dev->num_crtcs)) > + if (WARN_ON(pipe >= dev->num_crtcs)) { > + *vblanktime = (struct timeval) { 0 }; > return 0; > + } > > do { > seq = read_seqbegin(&vblank->seqlock); >
Looks good to me.
Reviewed-by: Mario Kleiner <mario.kleiner.de@gmail.com>
-mario
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