On Fr, 2020-01-17 at 16:47 +0100, Guido Günther wrote:
Hi, On Fri, Dec 13, 2019 at 09:53:41PM +0100, Arnd Bergmann wrote:
Most kernel interfaces that take a timespec require normalized representation with tv_nsec between 0 and NSEC_PER_SEC.
Passing values larger than 0x100000000ull further behaves differently on 32-bit and 64-bit kernels, and can cause the latter to spend a long time counting seconds in timespec64_sub()/set_normalized_timespec64().
Reject those large values at the user interface to enforce sane and portable behavior.
Signed-off-by: Arnd Bergmann arnd@arndb.de
drivers/gpu/drm/etnaviv/etnaviv_drv.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.c b/drivers/gpu/drm/etnaviv/etnaviv_drv.c index 1f9c01be40d7..95d72dc00280 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.c @@ -297,6 +297,9 @@ 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)
return -EINVAL;- obj = drm_gem_object_lookup(file, args->handle); if (!obj) return -ENOENT;
@@ -360,6 +363,9 @@ 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)
return -EINVAL;- if (args->pipe >= ETNA_MAX_PIPES) return -EINVAL;
@@ -411,6 +417,9 @@ 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)
return -EINVAL;- if (args->pipe >= ETNA_MAX_PIPES) return -EINVAL;
This breaks rendering here on arm64/gc7000 due to
ioctl(6, DRM_IOCTL_ETNAVIV_GEM_CPU_PREP or DRM_IOCTL_MSM_GEM_CPU_PREP, 0xfffff7888680) = -1 EINVAL (Invalid argument) ioctl(6, DRM_IOCTL_ETNAVIV_GEM_CPU_FINI or DRM_IOCTL_QXL_CLIENTCAP, 0xfffff78885e0) = 0 ioctl(6, DRM_IOCTL_ETNAVIV_GEM_CPU_PREP or DRM_IOCTL_MSM_GEM_CPU_PREP, 0xfffff7888680) = -1 EINVAL (Invalid argument) ioctl(6, DRM_IOCTL_ETNAVIV_GEM_CPU_FINI or DRM_IOCTL_QXL_CLIENTCAP, 0xfffff78885e0) = 0 ioctl(6, DRM_IOCTL_ETNAVIV_GEM_CPU_PREP or DRM_IOCTL_MSM_GEM_CPU_PREP, 0xfffff7888680) = -1 EINVAL (Invalid argument) ioctl(6, DRM_IOCTL_ETNAVIV_GEM_CPU_FINI or DRM_IOCTL_QXL_CLIENTCAP, 0xfffff78885e0) = 0
This is due to
get_abs_timeout(&req.timeout, 5000000000);in etna_bo_cpu_prep which can exceed NSEC_PER_SEC.
Should i send a patch to revert that change since it breaks existing userspace?
No need to revert. This patch has not been applied to the etnaviv tree yet, I guess it's just in one of Arnds branches feeding into -next.
That part of userspace is pretty dumb, as it misses to renormalize tv_nsec when it overflows the second boundary. So if what I see is correct it should be enough to allow 2 * NSEC_PER_SEC, which should both reject broken large timeout and keep existing userspace working.
Regards, Lucas