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 0e051eca3639..1fa01313d89f 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