1 files changed, 29 insertions, 13 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 0e051ec..1fa0131 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -405,30 +405,46 @@ static int
 i915_gem_execbuffer_relocate_object(struct drm_i915_gem_object *obj,
 				    struct eb_objects *eb)
 {
+#define N_RELOC(x) ((x) / sizeof(struct drm_i915_gem_relocation_entry))
+	struct drm_i915_gem_relocation_entry stack_reloc[N_RELOC(512)];
 	struct drm_i915_gem_relocation_entry __user *user_relocs;
 	struct drm_i915_gem_exec_object2 *entry = obj->exec_entry;
-	int i, ret;
+	int remain, ret;
 
 	user_relocs = (void __user *)(uintptr_t)entry->relocs_ptr;
-	for (i = 0; i < entry->relocation_count; i++) {
-		struct drm_i915_gem_relocation_entry reloc;
 
-		if (__copy_from_user_inatomic(&reloc,
-					      user_relocs+i,
-					      sizeof(reloc)))
+	remain = entry->relocation_count;
+	while (remain) {
+		struct drm_i915_gem_relocation_entry *r = stack_reloc;
+		int count = remain;
+		if (count > ARRAY_SIZE(stack_reloc))
+			count = ARRAY_SIZE(stack_reloc);
+		remain -= count;
+
+		if (__copy_from_user_inatomic(r, user_relocs, count*sizeof(r[0])))
 			return -EFAULT;
 
-		ret = i915_gem_execbuffer_relocate_entry(obj, eb, &reloc);
-		if (ret)
-			return ret;
+		do {
+			u64 offset = r->presumed_offset;
 
-		if (__copy_to_user_inatomic(&user_relocs[i].presumed_offset,
-					    &reloc.presumed_offset,
-					    sizeof(reloc.presumed_offset)))
-			return -EFAULT;
+			ret = i915_gem_execbuffer_relocate_entry(obj, eb, r);
+			if (ret)
+				return ret;
+
+			if (r->presumed_offset != offset &&
+			    __copy_to_user_inatomic(&user_relocs->presumed_offset,
+						    &r->presumed_offset,
+						    sizeof(r->presumed_offset))) {
+				return -EFAULT;
+			}
+
+			user_relocs++;
+			r++;
+		} while (--count);
 	}
 
 	return 0;
+#undef N_RELOC
 }
 
 static int