[Intel-gfx] [drm-intel:for-linux-next-fixes 3/4] drivers/gpu/drm/i915/i915_gem_execbuffer.c:1419:47: sparse: incorrect type in initializer (different address spaces)

[Daniel Vetter]

Adding intel-gfx & Jani.

We don't deref the userpointer, we just take the address of one of its
fields. Imo this is just sparse being dense, since all other address
arithmetic is fine with sparse. Is there some way to shut up sparse
here without making the code loook horrible?
-Daniel

On Fri, May 23, 2014 at 2:25 PM, kbuild test robot
<fengguang.wu at intel.com> wrote:
> tree:   git://anongit.freedesktop.org/drm-intel for-linux-next-fixes
> head:   c1240bd2842f6ec26d7dc1d9c845a197a41d33fe
> commit: 03055f30e32f28dfb24bfa5d3beb75eb7ce7f0d7 [3/4] drm/i915: Only copy back the modified fields to userspace from execbuffer
> reproduce: make C=1 CF=-D__CHECK_ENDIAN__
>
>
> sparse warnings: (new ones prefixed by >>)
>
>>> drivers/gpu/drm/i915/i915_gem_execbuffer.c:1419:47: sparse: incorrect type in initializer (different address spaces)
>    drivers/gpu/drm/i915/i915_gem_execbuffer.c:1419:47:    expected struct drm_i915_gem_exec_object2 *user_exec_list
>    drivers/gpu/drm/i915/i915_gem_execbuffer.c:1419:47:    got void [noderef] <asn:1>*
>>> drivers/gpu/drm/i915/i915_gem_execbuffer.c:1423:61: sparse: incorrect type in argument 1 (different address spaces)
>    drivers/gpu/drm/i915/i915_gem_execbuffer.c:1423:61:    expected void [noderef] <asn:1>*dst
>    drivers/gpu/drm/i915/i915_gem_execbuffer.c:1423:61:    got unsigned long long *<noident>
>
> vim +1419 drivers/gpu/drm/i915/i915_gem_execbuffer.c
>
>   1413          }
>   1414
>   1415          ret = i915_gem_do_execbuffer(dev, data, file, args, exec2_list);
>   1416          if (!ret) {
>   1417                  /* Copy the new buffer offsets back to the user's exec list. */
>   1418                  struct drm_i915_gem_exec_object2 *user_exec_list =
>> 1419                                     to_user_ptr(args->buffers_ptr);
>   1420                  int i;
>   1421
>   1422                  for (i = 0; i < args->buffer_count; i++) {
>> 1423                          ret = __copy_to_user(&user_exec_list[i].offset,
>   1424                                               &exec2_list[i].offset,
>   1425                                               sizeof(user_exec_list[i].offset));
>   1426                          if (ret) {
>
> ---
> 0-DAY kernel build testing backend              Open Source Technology Center
> http://lists.01.org/mailman/listinfo/kbuild                 Intel Corporation



-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch