[PATCH v2] net: Protect INET_ADDR_COOKIE on 32-bit architectures

From: Stephen Kitt
Date: Fri May 08 2020 - 08:05:23 EST


Commit c7228317441f ("net: Use a more standard macro for
INET_ADDR_COOKIE") added a __deprecated marker to the cookie name on
32-bit architectures, with the intent that the compiler would flag
uses of the name. However since commit 771c035372a0 ("deprecate the
'__deprecated' attribute warnings entirely and for good"),
__deprecated doesn't do anything and should be avoided.

This patch changes INET_ADDR_COOKIE to declare a dummy struct so that
any subsequent use of the cookie's name will in all likelihood break
the build. It also removes the __deprecated marker.

Signed-off-by: Stephen Kitt <steve@xxxxxxx>
---
Changes since v1:
- use a dummy struct rather than a typedef

include/net/inet_hashtables.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index ad64ba6a057f..889d9b00c905 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -301,8 +301,9 @@ static inline struct sock *inet_lookup_listener(struct net *net,
((__sk)->sk_bound_dev_if == (__sdif))) && \
net_eq(sock_net(__sk), (__net)))
#else /* 32-bit arch */
+/* Break the build if anything tries to use the cookie's name. */
#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \
- const int __name __deprecated __attribute__((unused))
+ struct {} __name __attribute__((unused))

#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif, __sdif) \
(((__sk)->sk_portpair == (__ports)) && \
--
2.20.1