lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 13 Dec 2017 12:56:37 -0800 From: Sinclair Yeh <syeh@...are.com> To: Arnd Bergmann <arnd@...db.de> Cc: VMware Graphics <linux-graphics-maintainer@...are.com>, Thomas Hellstrom <thellstrom@...are.com>, David Airlie <airlied@...ux.ie>, Deepak Singh Rawat <drawat@...are.com>, Tomi Valkeinen <tomi.valkeinen@...com>, Arvind Yadav <arvind.yadav.cs@...il.com>, Ravikant B Sharma <ravikant.s2@...sung.com>, Joe Perches <joe@...ches.com>, dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org Subject: Re: [PATCH] vmwgfx: use monotonic event timestamps This looks okay to me. Although we should change eaction->tv_* type to 64-bit as well. I'll roll this in to our next pull request. thanks, Sinclair On Mon, Nov 27, 2017 at 12:16:19PM +0100, Arnd Bergmann wrote: > DRM_VMW_EVENT_FENCE_SIGNALED (struct drm_vmw_event_fence) and > DRM_EVENT_VBLANK (struct drm_event_vblank) pass timestamps in 32-bit > seconds/microseconds format. > > As of commit c61eef726a78 ("drm: add support for monotonic vblank > timestamps"), other DRM drivers use monotonic times for drm_event_vblank, > but vmwgfx still uses CLOCK_REALTIME for both events, which suffers from > the y2038/y2106 overflow as well as time jumps. > > For consistency, this changes vmwgfx to use ktime_get_ts64 as well, > which solves those problems and avoids the deprecated do_gettimeofday() > function. > > This should be transparent to to user space, as long as it doesn't > compare the time against the result of gettimeofday(). > > Signed-off-by: Arnd Bergmann <arnd@...db.de> > --- > drivers/gpu/drm/vmwgfx/vmwgfx_fence.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c > index d6b1c509ae01..55214d0da66e 100644 > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c > @@ -897,11 +897,12 @@ static void vmw_event_fence_action_seq_passed(struct vmw_fence_action *action) > spin_lock_irq(&dev->event_lock); > > if (likely(eaction->tv_sec != NULL)) { > - struct timeval tv; > + struct timespec64 ts; > > - do_gettimeofday(&tv); > - *eaction->tv_sec = tv.tv_sec; > - *eaction->tv_usec = tv.tv_usec; > + ktime_get_ts64(&ts); > + /* monotonic time, so no y2038 overflow */ > + *eaction->tv_sec = ts.tv_sec; > + *eaction->tv_usec = ts.tv_nsec / NSEC_PER_USEC; > } > > drm_send_event_locked(dev, eaction->event); > -- > 2.9.0 >
Powered by blists - more mailing lists