According to your(Villie) reply, the *info has been checked info earlier, and I 
have read the code of framebuffer_check() and related drm_get_format_info() 
which it calls, but unfortunatelly, I haven't seen  judgement(check) for it. 
What I only found related with check is the sentence below (in 
*drm_format_info() in drivers/gpu/drm/drm_fourcc.c):
```
info = __drm_format_info(format);
WARN_ON(!info);
``` 
But to the best of my knowledge, "WARN_ON" only gives a dump_stack(), not  
discontinue the program going on, so it will indeed go to the below line in 
framebuffer_check() and raise an error:
```
for (i = 0; i < info->num_planes; i++) {
```
So maybe it will make  sense of my commited code.

Signed-off-by: Peng Hao <[email protected]>
---
 drivers/gpu/drm/drm_framebuffer.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/drm_framebuffer.c 
b/drivers/gpu/drm/drm_framebuffer.c
index aff3746dedfb..be7dd1998c04 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -194,6 +194,10 @@ static int framebuffer_check(struct drm_device *dev,
 
         /* now let the driver pick its own format info */
         info = drm_get_format_info(dev, r);
+        if (!info) {
+                drm_dbg_kms(dev, "no matched format info\n");
+                return -EFAULT;
+        }
 
         for (i = 0; i < info->num_planes; i++) {
                 unsigned int width = fb_plane_width(r->width, info, i);
-- 
2.37.1

Reply via email to