Hi Guido,
On Di, 2020-01-21 at 13:55 +0100, Guido Günther wrote:
> Hi,
> On Tue, Jan 21, 2020 at 12:45:25PM +0100, Arnd Bergmann wrote:
> > As Guido Günther reported, get_abs_timeout() in the etnaviv user space
> > sometimes passes timeouts with nanosecond values larger than 1000000000,
> > which gets rejected after my first patch.
> >
> > To avoid breaking this, while also not allowing completely arbitrary
> > values, set the limit to 1999999999 and use set_normalized_timespec64()
> > to get the correct format before comparing it.
>
> I'm seeing values up to 5 seconds so I need
>
> if (args->timeout.tv_nsec > (5 * NSEC_PER_SEC))
>
> to unbreak rendering. Which seems to match what mesa's get_abs_timeout()
> does and how it's invoked.
I have not tested this myself yet, only looked at the code. From the
code I quoted earlier, I don't see how we end up with 5 * NSEC_PER_SEC
in the tv_nsec member, even if the timeout passed to get_abs_timeout()
is 5 seconds.
Regards,
Lucas
> with that:
>
> Tested-by: Guido Günther <agx@xxxxxxxxxxx>
>
> Cheers,
> -- Guido
>
> > This also addresses the off-by-1 glitch reported by Ben Hutchings.
> >
> > Fixes: 172a216ff334 ("drm/etnaviv: reject timeouts with tv_nsec >= NSEC_PER_SEC")
> > Cc: Guido Günther <agx@xxxxxxxxxxx>
> > Link: https://patchwork.kernel.org/patch/11291089/
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > ---
> > drivers/gpu/drm/etnaviv/etnaviv_drv.c | 10 +++++++---
> > drivers/gpu/drm/etnaviv/etnaviv_drv.h | 6 ++----
> > 2 files changed, 9 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.c b/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> > index 3eb0f9223bea..d94740c123d3 100644
> > --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> > +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> > @@ -292,7 +292,11 @@ static int etnaviv_ioctl_gem_cpu_prep(struct drm_device *dev, void *data,
> > if (args->op & ~(ETNA_PREP_READ | ETNA_PREP_WRITE | ETNA_PREP_NOSYNC))
> > return -EINVAL;
> >
> > - if (args->timeout.tv_nsec > NSEC_PER_SEC)
> > + /*
> > + * existing user space passes non-normalized timespecs, but never
> > + * more than 2 seconds worth of nanoseconds
> > + */
> > + if (args->timeout.tv_nsec >= (2 * NSEC_PER_SEC))
> > return -EINVAL;
> >
> > obj = drm_gem_object_lookup(file, args->handle);
> > @@ -358,7 +362,7 @@ static int etnaviv_ioctl_wait_fence(struct drm_device *dev, void *data,
> > if (args->flags & ~(ETNA_WAIT_NONBLOCK))
> > return -EINVAL;
> >
> > - if (args->timeout.tv_nsec > NSEC_PER_SEC)
> > + if (args->timeout.tv_nsec >= (2 * NSEC_PER_SEC))
> > return -EINVAL;
> >
> > if (args->pipe >= ETNA_MAX_PIPES)
> > @@ -412,7 +416,7 @@ static int etnaviv_ioctl_gem_wait(struct drm_device *dev, void *data,
> > if (args->flags & ~(ETNA_WAIT_NONBLOCK))
> > return -EINVAL;
> >
> > - if (args->timeout.tv_nsec > NSEC_PER_SEC)
> > + if (args->timeout.tv_nsec >= (2 * NSEC_PER_SEC))
> > return -EINVAL;
> >
> > if (args->pipe >= ETNA_MAX_PIPES)
> > diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.h b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
> > index efc656efeb0f..3e47050af706 100644
> > --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.h
> > +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
> > @@ -109,12 +109,10 @@ static inline size_t size_vstruct(size_t nelem, size_t elem_size, size_t base)
> > static inline unsigned long etnaviv_timeout_to_jiffies(
> > const struct drm_etnaviv_timespec *timeout)
> > {
> > - struct timespec64 ts, to = {
> > - .tv_sec = timeout->tv_sec,
> > - .tv_nsec = timeout->tv_nsec,
> > - };
> > + struct timespec64 ts, to;
> >
> > ktime_get_ts64(&ts);
> > + set_normalized_timespec64(&to, timeout->tv_sec, timeout->tv_nsec);
> >
> > /* timeouts before "now" have already expired */
> > if (timespec64_compare(&to, &ts) <= 0)
> > --
> > 2.25.0
> >
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