target/linux/brcm2708/patches-4.4/0297-drm-vc4-Return-EFAULT-on-copy_from_user-failure.patch

   1 From 5ae2b2779bed5095268019d56394420e7c751c29 Mon Sep 17 00:00:00 2001
   2 From: Dan Carpenter <dan.carpenter@oracle.com>
   3 Date: Tue, 8 Mar 2016 15:09:41 +0300
   4 Subject: [PATCH 297/304] drm/vc4: Return -EFAULT on copy_from_user() failure
   5
   6 The copy_from_user() function returns the number of bytes not copied but
   7 we want to return a negative error code.
   8
   9 Fixes: 463873d57014 ('drm/vc4: Add an API for creating GPU shaders in GEM BOs.')
  10 Cc: stable@vger.kernel.org
  11 Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
  12 Reviewed-by: Eric Anholt <eric@anholt.net>
  13 Signed-off-by: Eric Anholt <eric@anholt.net>
  14 (cherry picked from commit 585cb132a48190b554aecda2ebc3e2911fcbb665)
  15 ---
  16  drivers/gpu/drm/vc4/vc4_bo.c | 7 ++++---
  17  1 file changed, 4 insertions(+), 3 deletions(-)
  18
  19 --- a/drivers/gpu/drm/vc4/vc4_bo.c
  20 +++ b/drivers/gpu/drm/vc4/vc4_bo.c
  21 @@ -519,11 +519,12 @@ vc4_create_shader_bo_ioctl(struct drm_de
  22         if (IS_ERR(bo))
  23                 return PTR_ERR(bo);
  24
  25 -       ret = copy_from_user(bo->base.vaddr,
  26 +       if (copy_from_user(bo->base.vaddr,
  27                              (void __user *)(uintptr_t)args->data,
  28 -                            args->size);
  29 -       if (ret != 0)
  30 +                            args->size)) {
  31 +               ret = -EFAULT;
  32                 goto fail;
  33 +       }
  34         /* Clear the rest of the memory from allocating from the BO
  35          * cache.
  36          */