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authorEric Dumazet <edumazet@google.com>2023-07-20 11:09:01 +0000
committerDavid S. Miller <davem@davemloft.net>2023-07-24 09:39:31 +0100
commitf5f80e32de12fad2813d37270e8364a03e6d3ef0 (patch)
tree40646cf495a3ae868afc96d9d63fba08834be509 /include
parent1671bcfd76fdc0b9e65153cf759153083755fe4c (diff)
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 <edumazet@google.com> Cc: Chao Wu <wwchao@google.com> Cc: Wei Wang <weiwan@google.com> Cc: Coco Li <lixiaoyan@google.com> Cc: YiFei Zhu <zhuyifei@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r--include/linux/ipv6.h15
-rw-r--r--include/net/sock.h1
2 files changed, 5 insertions, 11 deletions
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index ed3d110c2eb5..0295b47c10a3 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -200,14 +200,7 @@ struct inet6_cork {
u8 tclass;
};
-/**
- * struct ipv6_pinfo - ipv6 private area
- *
- * In the struct sock hierarchy (tcp6_sock, upd6_sock, etc)
- * this _must_ be the last member, so that inet6_sk_generic
- * is able to calculate its offset from the base struct sock
- * by using the struct proto->slab_obj_size member. -acme
- */
+/* struct ipv6_pinfo - ipv6 private area */
struct ipv6_pinfo {
struct in6_addr saddr;
struct in6_pktinfo sticky_pktinfo;
@@ -307,19 +300,19 @@ struct raw6_sock {
__u32 offset; /* checksum offset */
struct icmp6_filter filter;
__u32 ip6mr_table;
- /* ipv6_pinfo has to be the last member of raw6_sock, see inet6_sk_generic */
+
struct ipv6_pinfo inet6;
};
struct udp6_sock {
struct udp_sock udp;
- /* ipv6_pinfo has to be the last member of udp6_sock, see inet6_sk_generic */
+
struct ipv6_pinfo inet6;
};
struct tcp6_sock {
struct tcp_sock tcp;
- /* ipv6_pinfo has to be the last member of tcp6_sock, see inet6_sk_generic */
+
struct ipv6_pinfo inet6;
};
diff --git a/include/net/sock.h b/include/net/sock.h
index 2eb916d1ff64..7ae44bf866af 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1339,6 +1339,7 @@ struct proto {
struct kmem_cache *slab;
unsigned int obj_size;
+ unsigned int ipv6_pinfo_offset;
slab_flags_t slab_flags;
unsigned int useroffset; /* Usercopy region offset */
unsigned int usersize; /* Usercopy region size */