diff options
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 23f1a6bcee73..292a74f2fa87 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -300,6 +300,7 @@ i915_gem_shmem_pread(struct drm_device *dev, int shmem_page_offset, page_length, ret = 0; int obj_do_bit17_swizzling, page_do_bit17_swizzling; int hit_slowpath = 0; + int prefaulted = 0; int needs_clflush = 0; int release_page; @@ -368,6 +369,16 @@ i915_gem_shmem_pread(struct drm_device *dev, page_cache_get(page); mutex_unlock(&dev->struct_mutex); + if (!prefaulted) { + ret = fault_in_pages_writeable(user_data, remain); + /* Userspace is tricking us, but we've already clobbered + * its pages with the prefault and promised to write the + * data up to the first fault. Hence ignore any errors + * and just continue. */ + (void)ret; + prefaulted = 1; + } + vaddr = kmap(page); if (needs_clflush) drm_clflush_virt_range(vaddr + shmem_page_offset, @@ -431,11 +442,6 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data, args->size)) return -EFAULT; - ret = fault_in_pages_writeable((char __user *)(uintptr_t)args->data_ptr, - args->size); - if (ret) - return -EFAULT; - ret = i915_mutex_lock_interruptible(dev); if (ret) return ret; |