amdkfd: Copy from the proper user command pointer

From: Borislav Petkov <[email protected]>

8f1d57c17248 ("amdkfd: don't open-code memdup_user()") mistakenly uses an uninitialized local pointer, gcc complains:

drivers/gpu/drm/amd/amdkfd/kfd_chardev.c: In function ‘kfd_ioctl_dbg_address_watch’:
drivers/gpu/drm/amd/amdkfd/kfd_chardev.c:562:12: warning: ‘args_buff’ may be used uninitialized in this function [-Wmaybe-uninitialized]
args_buff = memdup_user(args_buff,
^

Fix it.

---
 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

index d321222fd92e..d2b49c026cf6 100644
@@ -558,8 +558,7 @@ static int kfd_ioctl_dbg_address_watch(struct file *filep,
 		return -EINVAL;
 
 	/* this is the actual buffer to work with */
-
-	args_buff = memdup_user(args_buff,
+	args_buff = memdup_user(cmd_from_user,
 				args->buf_size_in_bytes - sizeof(*args));
 	if (IS_ERR(args_buff))
 		return PTR_ERR(args_buff);

2.3.5

Mea culpa... Applied, and I wonder how the hell I'd missed that..