target/linux/brcm2708/patches-4.4/0275-drm-vc4-copy_to_user-returns-the-number-of-bytes-rem.patch

   1 From 543efa41ce1be43b927ddbb6c999063f8f4f9caa 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 275/304] drm/vc4: copy_to_user() returns the number of bytes
   5  remaining
   6
   7 The copy_to/from_user() functions return the number of bytes remaining
   8 to be copied.  We want to return error codes here.
   9
  10 Also it's a bad idea to print an error message if a copy from user fails
  11 because users can use that to spam /var/log/messages which is annoying
  12 so I removed those.
  13
  14 Fixes: 214613656b51 ('drm/vc4: Add an interface for capturing the GPU state after a hang.')
  15 Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
  16 Reviewed-by: Eric Anholt <eric@anholt.net>
  17 (cherry picked from commit 65c4777de54a39b2722a4b1ff3306d044014d511)
  18 ---
  19  drivers/gpu/drm/vc4/vc4_gem.c | 37 ++++++++++++++++++-------------------
  20  1 file changed, 18 insertions(+), 19 deletions(-)
  21
  22 --- a/drivers/gpu/drm/vc4/vc4_gem.c
  23 +++ b/drivers/gpu/drm/vc4/vc4_gem.c
  24 @@ -85,7 +85,7 @@ vc4_get_hang_state_ioctl(struct drm_devi
  25         struct vc4_dev *vc4 = to_vc4_dev(dev);
  26         unsigned long irqflags;
  27         u32 i;
  28 -       int ret;
  29 +       int ret = 0;
  30
  31         spin_lock_irqsave(&vc4->job_lock, irqflags);
  32         kernel_state = vc4->hang_state;
  33 @@ -133,9 +133,11 @@ vc4_get_hang_state_ioctl(struct drm_devi
  34                 bo_state[i].size = vc4_bo->base.base.size;
  35         }
  36
  37 -       ret = copy_to_user((void __user *)(uintptr_t)get_state->bo,
  38 -                          bo_state,
  39 -                          state->bo_count * sizeof(*bo_state));
  40 +       if (copy_to_user((void __user *)(uintptr_t)get_state->bo,
  41 +                        bo_state,
  42 +                        state->bo_count * sizeof(*bo_state)))
  43 +               ret = -EFAULT;
  44 +
  45         kfree(bo_state);
  46
  47  err_free:
  48 @@ -563,27 +565,24 @@ vc4_get_bcl(struct drm_device *dev, stru
  49         exec->shader_state = temp + exec_size;
  50         exec->shader_state_size = args->shader_rec_count;
  51
  52 -       ret = copy_from_user(bin,
  53 -                            (void __user *)(uintptr_t)args->bin_cl,
  54 -                            args->bin_cl_size);
  55 -       if (ret) {
  56 -               DRM_ERROR("Failed to copy in bin cl\n");
  57 +       if (copy_from_user(bin,
  58 +                          (void __user *)(uintptr_t)args->bin_cl,
  59 +                          args->bin_cl_size)) {
  60 +               ret = -EFAULT;
  61                 goto fail;
  62         }
  63
  64 -       ret = copy_from_user(exec->shader_rec_u,
  65 -                            (void __user *)(uintptr_t)args->shader_rec,
  66 -                            args->shader_rec_size);
  67 -       if (ret) {
  68 -               DRM_ERROR("Failed to copy in shader recs\n");
  69 +       if (copy_from_user(exec->shader_rec_u,
  70 +                          (void __user *)(uintptr_t)args->shader_rec,
  71 +                          args->shader_rec_size)) {
  72 +               ret = -EFAULT;
  73                 goto fail;
  74         }
  75
  76 -       ret = copy_from_user(exec->uniforms_u,
  77 -                            (void __user *)(uintptr_t)args->uniforms,
  78 -                            args->uniforms_size);
  79 -       if (ret) {
  80 -               DRM_ERROR("Failed to copy in uniforms cl\n");
  81 +       if (copy_from_user(exec->uniforms_u,
  82 +                          (void __user *)(uintptr_t)args->uniforms,
  83 +                          args->uniforms_size)) {
  84 +               ret = -EFAULT;
  85                 goto fail;
  86         }
  87