From f5f80e32de12fad2813d37270e8364a03e6d3ef0 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 20 Jul 2023 11:09:01 +0000 Subject: ipv6: remove hard coded limitation on ipv6_pinfo IPv6 inet sockets are supposed to have a "struct ipv6_pinfo" field at the end of their definition, so that inet6_sk_generic() can derive from socket size the offset of the "struct ipv6_pinfo". This is very fragile, and prevents adding bigger alignment in sockets, because inet6_sk_generic() does not work if the compiler adds padding after the ipv6_pinfo component. We are currently working on a patch series to reorganize TCP structures for better data locality and found issues similar to the one fixed in commit f5d547676ca0 ("tcp: fix tcp_inet6_sk() for 32bit kernels") Alternative would be to force an alignment on "struct ipv6_pinfo", greater or equal to __alignof__(any ipv6 sock) to ensure there is no padding. This does not look great. v2: fix typo in mptcp_proto_v6_init() (Paolo) Signed-off-by: Eric Dumazet Cc: Chao Wu Cc: Wei Wang Cc: Coco Li Cc: YiFei Zhu Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- net/ipv6/af_inet6.c | 4 ++-- net/ipv6/ping.c | 1 + net/ipv6/raw.c | 1 + net/ipv6/tcp_ipv6.c | 1 + net/ipv6/udp.c | 1 + net/ipv6/udplite.c | 1 + 6 files changed, 7 insertions(+), 2 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 5d593ddc0347..9f9c4b838664 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -102,9 +102,9 @@ bool ipv6_mod_enabled(void) } EXPORT_SYMBOL_GPL(ipv6_mod_enabled); -static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk) +static struct ipv6_pinfo *inet6_sk_generic(struct sock *sk) { - const int offset = sk->sk_prot->obj_size - sizeof(struct ipv6_pinfo); + const int offset = sk->sk_prot->ipv6_pinfo_offset; return (struct ipv6_pinfo *)(((u8 *)sk) + offset); } diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c index f804c11e2146..2a0e8bc07398 100644 --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -215,6 +215,7 @@ struct proto pingv6_prot = { .get_port = ping_get_port, .put_port = ping_unhash, .obj_size = sizeof(struct raw6_sock), + .ipv6_pinfo_offset = offsetof(struct raw6_sock, inet6), }; EXPORT_SYMBOL_GPL(pingv6_prot); diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index ac1cef094c5f..0fcf1b890807 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -1216,6 +1216,7 @@ struct proto rawv6_prot = { .hash = raw_hash_sk, .unhash = raw_unhash_sk, .obj_size = sizeof(struct raw6_sock), + .ipv6_pinfo_offset = offsetof(struct raw6_sock, inet6), .useroffset = offsetof(struct raw6_sock, filter), .usersize = sizeof_field(struct raw6_sock, filter), .h.raw_hash = &raw_v6_hashinfo, diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 4714eb695913..1b4529e833a1 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -2175,6 +2175,7 @@ struct proto tcpv6_prot = { .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem), .max_header = MAX_TCP_HEADER, .obj_size = sizeof(struct tcp6_sock), + .ipv6_pinfo_offset = offsetof(struct tcp6_sock, inet6), .slab_flags = SLAB_TYPESAFE_BY_RCU, .twsk_prot = &tcp6_timewait_sock_ops, .rsk_prot = &tcp6_request_sock_ops, diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index b7c972aa09a7..95c75d8f73d5 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1798,6 +1798,7 @@ struct proto udpv6_prot = { .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), .obj_size = sizeof(struct udp6_sock), + .ipv6_pinfo_offset = offsetof(struct udp6_sock, inet6), .h.udp_table = NULL, .diag_destroy = udp_abort, }; diff --git a/net/ipv6/udplite.c b/net/ipv6/udplite.c index 8e010d07917a..267d491e9707 100644 --- a/net/ipv6/udplite.c +++ b/net/ipv6/udplite.c @@ -67,6 +67,7 @@ struct proto udplitev6_prot = { .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), .obj_size = sizeof(struct udp6_sock), + .ipv6_pinfo_offset = offsetof(struct udp6_sock, inet6), .h.udp_table = &udplite_table, }; -- cgit v1.2.3