UPSTREAM: drm/i915: Report -EFAULT before pwrite fast path into shmemfs
When pwriting into shmemfs, the fast path pagecache_write does not
notice when it is writing to beyond the end of the truncated shmemfs
inode. Report -EFAULT directly when we try to use pwrite into the
!I915_MADV_WILLNEED object.
Fixes: 7c55e2c5772d ("drm/i915: Use pagecache write to prepopulate shmemfs from pwrite-ioctl")
Testcase: igt/gem_madvise/dontneed-before-pwrite
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171016202732.25459-1-chris@chris-wilson.co.uk
(cherry picked from commit a6d65e451cc4e7127698384868a4447ee7be7d16)
BUG=b:63740184
TEST=Build for poppy with USE=kasan and boot
Signed-off-by: Linux Patches Robot <linux-patches-robot@chromeos-missing-patches.google.com.iam.gserviceaccount.com>
Change-Id: I1eeb8f66e0be69b69c2476d9e7625801f7ddf33d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/2303545
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Commit-Queue: Guenter Roeck <groeck@chromium.org>
Tested-by: Guenter Roeck <groeck@chromium.org>
1 file changed
