Commit 9706d633 authored by Shannon Nelson's avatar Shannon Nelson Committed by Ben Hutchings

tcp: fix tcp_fastopen unaligned access complaints on sparc

[ Upstream commit 003c9410 ]

Fix up a data alignment issue on sparc by swapping the order
of the cookie byte array field with the length field in
struct tcp_fastopen_cookie, and making it a proper union
to clean up the typecasting.

This addresses log complaints like these:
    log_unaligned: 113 callbacks suppressed
    Kernel unaligned access at TPC[976490] tcp_try_fastopen+0x2d0/0x360
    Kernel unaligned access at TPC[9764ac] tcp_try_fastopen+0x2ec/0x360
    Kernel unaligned access at TPC[9764c8] tcp_try_fastopen+0x308/0x360
    Kernel unaligned access at TPC[9764e4] tcp_try_fastopen+0x324/0x360
    Kernel unaligned access at TPC[976490] tcp_try_fastopen+0x2d0/0x360

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarShannon Nelson <shannon.nelson@oracle.com>
Acked-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
parent c10be27d
......@@ -57,8 +57,13 @@ static inline unsigned int tcp_optlen(const struct sk_buff *skb)
/* TCP Fast Open Cookie as stored in memory */
struct tcp_fastopen_cookie {
s8 len;
union {
u8 val[TCP_FASTOPEN_COOKIE_MAX];
#if IS_ENABLED(CONFIG_IPV6)
struct in6_addr addr;
#endif
};
s8 len;
};
/* This defines a selective acknowledgement block. */
......
......@@ -112,7 +112,7 @@ static bool tcp_fastopen_cookie_gen(struct request_sock *req,
struct tcp_fastopen_cookie tmp;
if (__tcp_fastopen_cookie_gen(&ip6h->saddr, &tmp)) {
struct in6_addr *buf = (struct in6_addr *) tmp.val;
struct in6_addr *buf = &tmp.addr;
int i = 4;
for (i = 0; i < 4; i++)
......
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