drm/vmwgfx: use core drm to extend/check vmw_execbuf_ioctl

Currently vmw_execbuf_ioctl() open-codes the permission checking, size
extending and copying that is already done in core drm.

Kill all the duplication, adding a few comments for clarity.

Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Tested-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190522164119.24139-3-emil.l.velikov@gmail.com

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index fe0a679..275d90f 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -186,7 +186,7 @@ static const struct drm_ioctl_desc vmw_ioctls[] = {
                      DRM_RENDER_ALLOW),
        VMW_IOCTL_DEF(VMW_REF_SURFACE, vmw_surface_reference_ioctl,
                      DRM_AUTH | DRM_RENDER_ALLOW),
-       VMW_IOCTL_DEF(VMW_EXECBUF, NULL, DRM_AUTH |
+       VMW_IOCTL_DEF(VMW_EXECBUF, vmw_execbuf_ioctl, DRM_AUTH |
                      DRM_RENDER_ALLOW),
        VMW_IOCTL_DEF(VMW_FENCE_WAIT, vmw_fence_obj_wait_ioctl,
                      DRM_RENDER_ALLOW),
@@ -1117,15 +1117,7 @@ static long vmw_generic_ioctl(struct file *filp, unsigned int cmd,
                        &vmw_ioctls[nr - DRM_COMMAND_BASE];
 
                if (nr == DRM_COMMAND_BASE + DRM_VMW_EXECBUF) {
-                       ret = (long) drm_ioctl_permit(ioctl->flags, file_priv);
-                       if (unlikely(ret != 0))
-                               return ret;
-
-                       if (unlikely((cmd & (IOC_IN | IOC_OUT)) != IOC_IN))
-                               goto out_io_encoding;
-
-                       return (long) vmw_execbuf_ioctl(dev, arg, file_priv,
-                                                       _IOC_SIZE(cmd));
+                       return ioctl_func(filp, cmd, arg);
                } else if (nr == DRM_COMMAND_BASE + DRM_VMW_UPDATE_LAYOUT) {
                        if (!drm_is_current_master(file_priv) &&
                            !capable(CAP_SYS_ADMIN))

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index 0bf13d3..dbb04db 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -910,8 +910,8 @@ static inline struct page *vmw_piter_page(struct vmw_piter *viter)
  * Command submission - vmwgfx_execbuf.c
  */
 
-extern int vmw_execbuf_ioctl(struct drm_device *dev, unsigned long data,
-                            struct drm_file *file_priv, size_t size);
+extern int vmw_execbuf_ioctl(struct drm_device *dev, void *data,
+                            struct drm_file *file_priv);
 extern int vmw_execbuf_process(struct drm_file *file_priv,
                               struct vmw_private *dev_priv,
                               void __user *user_commands,

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
index 33533d1..ff86d49 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -3995,54 +3995,40 @@ void vmw_execbuf_release_pinned_bo(struct vmw_private *dev_priv)
        mutex_unlock(&dev_priv->cmdbuf_mutex);
 }
 
-int vmw_execbuf_ioctl(struct drm_device *dev, unsigned long data,
-                     struct drm_file *file_priv, size_t size)
+int vmw_execbuf_ioctl(struct drm_device *dev, void *data,
+                     struct drm_file *file_priv)
 {
        struct vmw_private *dev_priv = vmw_priv(dev);
-       struct drm_vmw_execbuf_arg arg;
+       struct drm_vmw_execbuf_arg *arg = data;
        int ret;
-       static const size_t copy_offset[] = {
-               offsetof(struct drm_vmw_execbuf_arg, context_handle),
-               sizeof(struct drm_vmw_execbuf_arg)};
        struct dma_fence *in_fence = NULL;
 
-       if (unlikely(size < copy_offset[0])) {
-               VMW_DEBUG_USER("Invalid command size, ioctl %d\n",
-                              DRM_VMW_EXECBUF);
-               return -EINVAL;
-       }
-
-       if (copy_from_user(&arg, (void __user *) data, copy_offset[0]) != 0)
-               return -EFAULT;
-
        /*
         * Extend the ioctl argument while maintaining backwards compatibility:
-        * We take different code paths depending on the value of arg.version.
+        * We take different code paths depending on the value of arg->version.
+        *
+        * Note: The ioctl argument is extended and zeropadded by core DRM.
         */
-       if (unlikely(arg.version > DRM_VMW_EXECBUF_VERSION ||
-                    arg.version == 0)) {
+       if (unlikely(arg->version > DRM_VMW_EXECBUF_VERSION ||
+                    arg->version == 0)) {
                VMW_DEBUG_USER("Incorrect execbuf version.\n");
                return -EINVAL;
        }
 
-       if (arg.version > 1 &&
-           copy_from_user(&arg.context_handle,
-                          (void __user *) (data + copy_offset[0]),
-                          copy_offset[arg.version - 1] - copy_offset[0]) != 0)
-               return -EFAULT;
-
-       switch (arg.version) {
+       switch (arg->version) {
        case 1:
-               arg.context_handle = (uint32_t) -1;
+               /* For v1 core DRM have extended + zeropadded the data */
+               arg->context_handle = (uint32_t) -1;
                break;
        case 2:
        default:
+               /* For v2 and later core DRM would have correctly copied it */
                break;
        }
 
        /* If imported a fence FD from elsewhere, then wait on it */
-       if (arg.flags & DRM_VMW_EXECBUF_FLAG_IMPORT_FENCE_FD) {
-               in_fence = sync_file_get_fence(arg.imported_fence_fd);
+       if (arg->flags & DRM_VMW_EXECBUF_FLAG_IMPORT_FENCE_FD) {
+               in_fence = sync_file_get_fence(arg->imported_fence_fd);
 
                if (!in_fence) {
                        VMW_DEBUG_USER("Cannot get imported fence\n");
@@ -4059,11 +4045,11 @@ int vmw_execbuf_ioctl(struct drm_device *dev, unsigned long data,
                return ret;
 
        ret = vmw_execbuf_process(file_priv, dev_priv,
-                                 (void __user *)(unsigned long)arg.commands,
-                                 NULL, arg.command_size, arg.throttle_us,
-                                 arg.context_handle,
-                                 (void __user *)(unsigned long)arg.fence_rep,
-                                 NULL, arg.flags);
+                                 (void __user *)(unsigned long)arg->commands,
+                                 NULL, arg->command_size, arg->throttle_us,
+                                 arg->context_handle,
+                                 (void __user *)(unsigned long)arg->fence_rep,
+                                 NULL, arg->flags);
 
        ttm_read_unlock(&dev_priv->reservation_sem);
        if (unlikely(ret != 0))