drm/i915: Large page offsets for pread/pwrite

Handle integer overflow when computing the sub-page length for shmem
backed pread/pwrite.

Reported-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181012140228.29783-1-chris@chris-wilson.co.uk
(cherry picked from commit a5e856a534)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
This commit is contained in:
Chris Wilson 2018-10-12 15:02:28 +01:00 committed by Rodrigo Vivi
parent e3118a038d
commit ab0d6a1418

View file

@ -1127,11 +1127,7 @@ i915_gem_shmem_pread(struct drm_i915_gem_object *obj,
offset = offset_in_page(args->offset);
for (idx = args->offset >> PAGE_SHIFT; remain; idx++) {
struct page *page = i915_gem_object_get_page(obj, idx);
int length;
length = remain;
if (offset + length > PAGE_SIZE)
length = PAGE_SIZE - offset;
unsigned int length = min_t(u64, remain, PAGE_SIZE - offset);
ret = shmem_pread(page, offset, length, user_data,
page_to_phys(page) & obj_do_bit17_swizzling,
@ -1575,11 +1571,7 @@ i915_gem_shmem_pwrite(struct drm_i915_gem_object *obj,
offset = offset_in_page(args->offset);
for (idx = args->offset >> PAGE_SHIFT; remain; idx++) {
struct page *page = i915_gem_object_get_page(obj, idx);
int length;
length = remain;
if (offset + length > PAGE_SIZE)
length = PAGE_SIZE - offset;
unsigned int length = min_t(u64, remain, PAGE_SIZE - offset);
ret = shmem_pwrite(page, offset, length, user_data,
page_to_phys(page) & obj_do_bit17_swizzling,