sockptr: let copy_struct_from_sockptr() use copy_struct_from_bounce_buffer()

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@gmail.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: Francesco Ruggeri <fruggeri@arista.com>
Cc: Salam Noureddine <noureddine@arista.com>
Cc: David Ahern <dsahern@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Michal Luczaj <mhal@rbox.co>
Cc: David Wei <dw@davidwei.uk>
Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Xin Long <lucien.xin@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Kuniyuki Iwashima <kuniyu@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Simon Horman <horms@kernel.org>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Christian Brauner <brauner@kernel.org>
CC: Kees Cook <keescook@chromium.org>
Cc: netdev@vger.kernel.org
Cc: linux-bluetooth@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Link: https://patch.msgid.link/b9b7e22664a53251d7ad099b12aead8b599c1257.1775576651.git.metze@samba.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h
index ba88f4d78c1b1687d01cc8ba609becab9f304fd6..706a8526cf3c6713a531359171c631354e26e1cd 100644 (file)
--- 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,