On 9/28/22 11:51 AM, Jani Nikula wrote:
On Wed, 28 Sep 2022, Gwan-gyeong Mun <gwan-gyeong.mun@xxxxxxxxx> wrote:
diff --git a/drivers/gpu/drm/i915/i915_scatterlist.h b/drivers/gpu/drm/i915/i915_scatterlist.h
index 9ddb3e743a3e..1d1802beb42b 100644
--- a/drivers/gpu/drm/i915/i915_scatterlist.h
+++ b/drivers/gpu/drm/i915/i915_scatterlist.h
@@ -220,4 +220,15 @@ struct i915_refct_sgt *i915_rsgt_from_buddy_resource(struct ttm_resource *res,
u64 region_start,
u32 page_alignment);
+/* Wrap scatterlist.h to sanity check for integer truncation */
+typedef unsigned int __sg_size_t; /* see linux/scatterlist.h */
+#define sg_alloc_table(sgt, nents, gfp) \
+ overflows_type(nents, __sg_size_t) ? -E2BIG \
+ : ((sg_alloc_table)(sgt, (__sg_size_t)(nents), gfp))
+
+#define sg_alloc_table_from_pages_segment(sgt, pages, npages, offset, size, max_segment, gfp) \
+ overflows_type(npages, __sg_size_t) ? -E2BIG \
+ : ((sg_alloc_table_from_pages_segment)(sgt, pages, (__sg_size_t)(npages), offset, \
+ size, max_segment, gfp))
+
#endif
No. I don't think we should shadow sg_alloc_table() and
sg_alloc_table_from_pages_segment().
Either get this in scatterlist.h (preferred) or prefix with i915_ or
whatever to indicate it's our local thing.
i915_scatterlist.h already has too much scatterlist "namespace" abuse
that I'd rather see gone than violated more.
Hi Jani,
Thanks for you comments.
I will update this patch by removing the shadowing of
sg_alloc_table_from_pages_segment() / sg_alloc_table(), so that the
caller checks when overflow checking is required.
Br,
G.G.
BR,
Jani.
