drm/amdgpu: make amdgpu_user_wait_ioctl more resilent v2

When the memory allocated by userspace isn't sufficient for all the
fences then just wait on them instead of returning an error.

v2: use correct variable as pointed out by Sunil

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Sunil Khatri <sunil.khatri@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
index 781896c9fd26701e40aa8710697fb3df0c89f88c..f77fc210cb9395eb49cfdfd866afdae556109963 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
@@ -705,7 +705,7 @@ amdgpu_userq_wait_count_fences(struct drm_file *filp,
                        num_fences++;
        }
 
-       wait_info->num_fences = num_fences;
+       wait_info->num_fences = min(num_fences, USHRT_MAX);
        r = 0;
 
 error_unlock:
@@ -714,6 +714,19 @@ error_unlock:
        return r;
 }
 
+static int
+amdgpu_userq_wait_add_fence(struct drm_amdgpu_userq_wait *wait_info,
+                           struct dma_fence **fences, unsigned int *num_fences,
+                           struct dma_fence *fence)
+{
+       /* As fallback shouldn't userspace allocate enough space */
+       if (*num_fences >= wait_info->num_fences)
+               return dma_fence_wait(fence, true);
+
+       fences[(*num_fences)++] = dma_fence_get(fence);
+       return 0;
+}
+
 static int
 amdgpu_userq_wait_return_fence_info(struct drm_file *filp,
                                    struct drm_amdgpu_userq_wait *wait_info,
@@ -757,13 +770,12 @@ amdgpu_userq_wait_return_fence_info(struct drm_file *filp,
                        goto free_fences;
 
                dma_fence_unwrap_for_each(f, &iter, fence) {
-                       if (num_fences >= wait_info->num_fences) {
-                               r = -EINVAL;
+                       r = amdgpu_userq_wait_add_fence(wait_info, fences,
+                                                       &num_fences, f);
+                       if (r) {
                                dma_fence_put(fence);
                                goto free_fences;
                        }
-
-                       fences[num_fences++] = dma_fence_get(f);
                }
 
                dma_fence_put(fence);
@@ -780,14 +792,12 @@ amdgpu_userq_wait_return_fence_info(struct drm_file *filp,
                if (r)
                        goto free_fences;
 
-               if (num_fences >= wait_info->num_fences) {
-                       dma_fence_put(fence);
-                       r = -EINVAL;
+               r = amdgpu_userq_wait_add_fence(wait_info, fences,
+                                               &num_fences, fence);
+               dma_fence_put(fence);
+               if (r)
                        goto free_fences;
-               }
 
-               /* Give the reference to the fence array */
-               fences[num_fences++] = fence;
        }
 
        /* Lock all the GEM objects */
@@ -817,12 +827,10 @@ amdgpu_userq_wait_return_fence_info(struct drm_file *filp,
 
                dma_resv_for_each_fence(&resv_cursor, gobj_read[i]->resv,
                                        DMA_RESV_USAGE_READ, fence) {
-                       if (num_fences >= wait_info->num_fences) {
-                               r = -EINVAL;
+                       r = amdgpu_userq_wait_add_fence(wait_info, fences,
+                                                       &num_fences, fence);
+                       if (r)
                                goto error_unlock;
-                       }
-
-                       fences[num_fences++] = dma_fence_get(fence);
                }
        }
 
@@ -833,12 +841,10 @@ amdgpu_userq_wait_return_fence_info(struct drm_file *filp,
 
                dma_resv_for_each_fence(&resv_cursor, gobj_write[i]->resv,
                                        DMA_RESV_USAGE_WRITE, fence) {
-                       if (num_fences >= wait_info->num_fences) {
-                               r = -EINVAL;
+                       r = amdgpu_userq_wait_add_fence(wait_info, fences,
+                                                       &num_fences, fence);
+                       if (r)
                                goto error_unlock;
-                       }
-
-                       fences[num_fences++] = dma_fence_get(fence);
                }
        }