[PATCH 4/5] sockptr: let copy_struct_from_sockptr() use copy_struct_from_bounce_buffer()

[Stefan Metzmacher]

The world would be better without sockptr_t, but this at least
simplifies copy_struct_from_sockptr() to be just a dispatcher for
copy_struct_from_user() or copy_struct_from_bounce_buffer() without any
special logic on its own.

Cc: Dmitry Safonov <0x7f454c46@xxxxxxxxx>
Cc: Dmitry Safonov <dima@xxxxxxxxxx>
Cc: Francesco Ruggeri <fruggeri@xxxxxxxxxx>
Cc: Salam Noureddine <noureddine@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Michal Luczaj <mhal@xxxxxxx>
Cc: David Wei <dw@xxxxxxxxxxx>
Cc: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Cc: Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx>
Cc: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Cc: Xin Long <lucien.xin@xxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: Willem de Bruijn <willemb@xxxxxxxxxx>
Cc: Neal Cardwell <ncardwell@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Simon Horman <horms@xxxxxxxxxx>
Cc: Aleksa Sarai <cyphar@xxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
CC: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: linux-bluetooth@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Stefan Metzmacher <metze@xxxxxxxxx>
---
 include/linux/sockptr.h | 16 +---------------
 1 file changed, 1 insertion(+), 15 deletions(-)

diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h
index ba88f4d78c1b..706a8526cf3c 100644
--- a/include/linux/sockptr.h
+++ b/include/linux/sockptr.h
@@ -87,24 +87,10 @@ static inline int copy_safe_from_sockptr(void *dst, size_t ksize,
 static inline int copy_struct_from_sockptr(void *dst, size_t ksize,
 		sockptr_t src, size_t usize)
 {
-	size_t size = min(ksize, usize);
-	size_t rest = max(ksize, usize) - size;
-
 	if (!sockptr_is_kernel(src))
 		return copy_struct_from_user(dst, ksize, src.user, usize);
 
-	if (usize < ksize) {
-		memset(dst + size, 0, rest);
-	} else if (usize > ksize) {
-		char *p = src.kernel;
-
-		while (rest--) {
-			if (*p++)
-				return -E2BIG;
-		}
-	}
-	memcpy(dst, src.kernel, size);
-	return 0;
+	return copy_struct_from_bounce_buffer(dst, ksize, src.kernel, usize);
 }
 
 static inline int copy_to_sockptr_offset(sockptr_t dst, size_t offset,
-- 
2.43.0