[PATCH 2/3] drm/vmwgfx: Use memdup_user() rather than duplicating its implementation

SF Markus Elfring
2016-09-23T16:38:03Z

Date: Fri, 23 Sep 2016 17:26:02 +0200

* Reuse existing functionality from memdup_user() instead of keeping
duplicate source code.

* Try this copy operation before allocating memory for the data structure
member "offsets".

* Delete the local variable "user_sizes" which became unnecessary
with this refactoring.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 21 +++++----------------
1 file changed, 5 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
index f557549..15504c6 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
@@ -700,7 +700,6 @@ int vmw_surface_define_ioctl(struct drm_device *dev, void *data,
struct drm_vmw_surface_create_req *req = &arg->req;
struct drm_vmw_surface_arg *rep = &arg->rep;
struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
- struct drm_vmw_size __user *user_sizes;
int ret;
int i, j;
uint32_t cur_bo_offset;
@@ -763,11 +762,11 @@ int vmw_surface_define_ioctl(struct drm_device *dev, void *data,
memcpy(srf->mip_levels, req->mip_levels, sizeof(srf->mip_levels));
srf->num_sizes = num_sizes;
user_srf->size = size;
- srf->sizes = kmalloc_array(srf->num_sizes,
- sizeof(*srf->sizes),
- GFP_KERNEL);
- if (unlikely(srf->sizes = NULL)) {
- ret = -ENOMEM;
+ srf->sizes = memdup_user((struct drm_vmw_size __user *)(unsigned long)
+ req->size_addr,
+ sizeof(*srf->sizes) * srf->num_sizes);
+ if (IS_ERR(srf->sizes)) {
+ ret = PTR_ERR(srf->sizes);
goto out_no_sizes;
}
srf->offsets = kmalloc_array(srf->num_sizes,
@@ -778,16 +777,6 @@ int vmw_surface_define_ioctl(struct drm_device *dev, void *data,
goto out_no_offsets;
}

- user_sizes = (struct drm_vmw_size __user *)(unsigned long)
- req->size_addr;
-
- ret = copy_from_user(srf->sizes, user_sizes,
- srf->num_sizes * sizeof(*srf->sizes));
- if (unlikely(ret != 0)) {
- ret = -EFAULT;
- goto out_no_copy;
- }
-
srf->base_size = *srf->sizes;
srf->autogen_filter = SVGA3D_TEX_FILTER_NONE;
srf->multisample_count = 0;
--
2.10.0