diff options
| author | Eric Dumazet <edumazet@google.com> | 2023-07-20 11:09:01 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-07-24 09:39:31 +0100 |
| commit | f5f80e32de12fad2813d37270e8364a03e6d3ef0 (patch) | |
| tree | 40646cf495a3ae868afc96d9d63fba08834be509 /include | |
| parent | 1671bcfd76fdc0b9e65153cf759153083755fe4c (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.h | 15 | ||||
| -rw-r--r-- | include/net/sock.h | 1 |
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 */ |