target/linux/brcm2708/patches-4.4/0271-drm-vc4-copy_to_user-returns-the-number-of-bytes-rem.patch

   1 From e1d56edafff76ade96b5dce25e7cf1300213929b Mon Sep 17 00:00:00 2001
   2 From: Dan Carpenter <dan.carpenter@oracle.com>
   3 Date: Thu, 17 Dec 2015 15:36:28 +0300
   4 Subject: [PATCH] drm/vc4: copy_to_user() returns the number of bytes remaining
   5
   6 The copy_to/from_user() functions return the number of bytes remaining
   7 to be copied.  We want to return error codes here.
   8
   9 Also it's a bad idea to print an error message if a copy from user fails
  10 because users can use that to spam /var/log/messages which is annoying
  11 so I removed those.
  12
  13 Fixes: 214613656b51 ('drm/vc4: Add an interface for capturing the GPU state after a hang.')
  14 Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
  15 Reviewed-by: Eric Anholt <eric@anholt.net>
  16 (cherry picked from commit 65c4777de54a39b2722a4b1ff3306d044014d511)
  17 ---
  18  drivers/gpu/drm/vc4/vc4_gem.c | 37 ++++++++++++++++++-------------------
  19  1 file changed, 18 insertions(+), 19 deletions(-)
  20
  21 --- a/drivers/gpu/drm/vc4/vc4_gem.c
  22 +++ b/drivers/gpu/drm/vc4/vc4_gem.c
  23 @@ -85,7 +85,7 @@ vc4_get_hang_state_ioctl(struct drm_devi
  24         struct vc4_dev *vc4 = to_vc4_dev(dev);
  25         unsigned long irqflags;
  26         u32 i;
  27 -       int ret;
  28 +       int ret = 0;
  29
  30         spin_lock_irqsave(&vc4->job_lock, irqflags);
  31         kernel_state = vc4->hang_state;
  32 @@ -133,9 +133,11 @@ vc4_get_hang_state_ioctl(struct drm_devi
  33                 bo_state[i].size = vc4_bo->base.base.size;
  34         }
  35
  36 -       ret = copy_to_user((void __user *)(uintptr_t)get_state->bo,
  37 -                          bo_state,
  38 -                          state->bo_count * sizeof(*bo_state));
  39 +       if (copy_to_user((void __user *)(uintptr_t)get_state->bo,
  40 +                        bo_state,
  41 +                        state->bo_count * sizeof(*bo_state)))
  42 +               ret = -EFAULT;
  43 +
  44         kfree(bo_state);
  45
  46  err_free:
  47 @@ -563,27 +565,24 @@ vc4_get_bcl(struct drm_device *dev, stru
  48         exec->shader_state = temp + exec_size;
  49         exec->shader_state_size = args->shader_rec_count;
  50
  51 -       ret = copy_from_user(bin,
  52 -                            (void __user *)(uintptr_t)args->bin_cl,
  53 -                            args->bin_cl_size);
  54 -       if (ret) {
  55 -               DRM_ERROR("Failed to copy in bin cl\n");
  56 +       if (copy_from_user(bin,
  57 +                          (void __user *)(uintptr_t)args->bin_cl,
  58 +                          args->bin_cl_size)) {
  59 +               ret = -EFAULT;
  60                 goto fail;
  61         }
  62
  63 -       ret = copy_from_user(exec->shader_rec_u,
  64 -                            (void __user *)(uintptr_t)args->shader_rec,
  65 -                            args->shader_rec_size);
  66 -       if (ret) {
  67 -               DRM_ERROR("Failed to copy in shader recs\n");
  68 +       if (copy_from_user(exec->shader_rec_u,
  69 +                          (void __user *)(uintptr_t)args->shader_rec,
  70 +                          args->shader_rec_size)) {
  71 +               ret = -EFAULT;
  72                 goto fail;
  73         }
  74
  75 -       ret = copy_from_user(exec->uniforms_u,
  76 -                            (void __user *)(uintptr_t)args->uniforms,
  77 -                            args->uniforms_size);
  78 -       if (ret) {
  79 -               DRM_ERROR("Failed to copy in uniforms cl\n");
  80 +       if (copy_from_user(exec->uniforms_u,
  81 +                          (void __user *)(uintptr_t)args->uniforms,
  82 +                          args->uniforms_size)) {
  83 +               ret = -EFAULT;
  84                 goto fail;
  85         }
  86