Re: [PATCH v3] drm/i915/gem: Zero-initialize the eb.vma array in i915_gem_do_execbuffer()

Hi Krzysztof,

[...]

@@ -3375,7 +3360,9 @@ i915_gem_do_execbuffer(struct drm_device *dev, eb.exec = exec; eb.vma = (struct eb_vma *)(exec + args->buffer_count + 1);

• eb.vma[0].vma = NULL;

• memset(eb.vma, 0x00, args->buffer_count * sizeof(struct eb_vma));
• eb.batch_pool = NULL;

eb.invalid_flags = __EXEC_OBJECT_UNKNOWN_FLAGS; @@ -3584,7 +3571,16 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data, if (err) return err;

• /* Allocate extra slots for use by the command parser */

• /*

• * Allocate extra slots for use by the command parser.
  

• *
  

• * Note that this allocation handles two different arrays (the
  

• * exec2_list array, and the eventual eb.vma array introduced in
  

• * i915_gem_do_execubuffer()), that reside in virtually contiguous
  

• * memory. Also note that the allocation doesn't fill the area with
  

• * zeros (the first part doesn't need to be), but the second part only
  

• * is explicitly zeroed later in i915_gem_do_execbuffer().
  

I get the gist of this comment, but I think you could reword the last sentence: "Also note that the allocation doesn't fill the area with zeros, because it is unnecessary for exec2_list array, and eb.vma is explicitly zeroed later in i915_gem_do_execbuffer()."

• */
  

  exec2_list = kvmalloc_array(count + 2, eb_element_size(), __GFP_NOWARN | GFP_KERNEL); if (exec2_list == NULL) {

-- 2.45.2