kernel/linux.git/include/net/route.h, branch v6.4.15

net: annotate data-races around sk->sk_mark

2023-08-11T10:14:13+00:00

[ Upstream commit 3c5b4d69c358a9275a8de98f87caf6eda644b086 ] sk->sk_mark is often read while another thread could change the value. Fixes: 4a19ec5800fc ("[NET]: Introducing socket mark socket option.") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: dst: Prevent false sharing vs. dst_entry:: __refcnt

2023-03-29T01:52:22+00:00

dst_entry::__refcnt is highly contended in scenarios where many connections happen from and to the same IP. The reference count is an atomic_t, so the reference count operations have to take the cache-line exclusive. Aside of the unavoidable reference count contention there is another significant problem which is caused by that: False sharing. perf top identified two affected read accesses. dst_entry::lwtstate and rtable::rt_genid. dst_entry:__refcnt is located at offset 64 of dst_entry, which puts it into a seperate cacheline vs. the read mostly members located at the beginning of the struct. That prevents false sharing vs. the struct members in the first 64 bytes of the structure, but there is also dst_entry::lwtstate which is located after the reference count and in the same cache line. This member is read after a reference count has been acquired. struct rtable embeds a struct dst_entry at offset 0. struct dst_entry has a size of 112 bytes, which means that the struct members of rtable which follow the dst member share the same cache line as dst_entry::__refcnt. Especially rtable::rt_genid is also read by the contexts which have a reference count acquired already. When dst_entry:__refcnt is incremented or decremented via an atomic operation these read accesses stall. This was found when analysing the memtier benchmark in 1:100 mode, which amplifies the problem extremly. Move the rt[6i]_uncached[_list] members out of struct rtable and struct rt6_info into struct dst_entry to provide padding and move the lwtstate member after that so it ends up in the same cache line. The resulting improvement depends on the micro-architecture and the number of CPUs. It ranges from +20% to +120% with a localhost memtier/memcached benchmark. [ tglx: Rearrange struct ] Signed-off-by: Wangyang Guo Signed-off-by: Arjan van de Ven Signed-off-by: Thomas Gleixner Reviewed-by: Eric Dumazet Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20230323102800.042297517@linutronix.de Signed-off-by: Jakub Kicinski

net: add a couple of helpers for iph tot_len

2023-02-02T04:54:27+00:00

This patch adds three APIs to replace the iph->tot_len setting and getting in all places where IPv4 BIG TCP packets may reach, they will be used in the following patches. Note that iph_totlen() will be used when iph is not in linear data of the skb. Signed-off-by: Xin Long Reviewed-by: David Ahern Reviewed-by: Eric Dumazet Signed-off-by: Jakub Kicinski

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next

2022-07-25T12:25:39+00:00

Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2022-07-20 1) Don't set DST_NOPOLICY in IPv4, a recent patch made this superfluous. From Eyal Birger. 2) Convert alg_key to flexible array member to avoid an iproute2 compile warning when built with gcc-12. From Stephen Hemminger. 3) xfrm_register_km and xfrm_unregister_km do always return 0 so change the type to void. From Zhengchao Shao. 4) Fix spelling mistake in esp6.c From Zhang Jiaming. 5) Improve the wording of comment above XFRM_OFFLOAD flags. From Petr Vaněk. Please pull or let me know if there are problems. ==================== Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2022-07-21T20:03:39+00:00

No conflicts. Signed-off-by: Jakub Kicinski

ip: Fix data-races around sysctl_ip_default_ttl.

2022-07-15T10:49:55+00:00

While reading sysctl_ip_default_ttl, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

net: change the type of ip_route_input_rcu to static

2022-07-12T13:08:45+00:00

The type of ip_route_input_rcu should be static. Signed-off-by: Zhengchao Shao Link: https://lore.kernel.org/r/20220711073549.8947-1-shaozhengchao@huawei.com Signed-off-by: Paolo Abeni

xfrm: no need to set DST_NOPOLICY in IPv4

2022-06-10T09:01:36+00:00

This is a cleanup patch following commit e6175a2ed1f1 ("xfrm: fix "disable_policy" flag use when arriving from different devices") which made DST_NOPOLICY no longer be used for inbound policy checks. On outbound the flag was set, but never used. As such, avoid setting it altogether and remove the nopolicy argument from rt_dst_alloc(). Signed-off-by: Eyal Birger Reviewed-by: Nicolas Dichtel Signed-off-by: Steffen Klassert

ipv4: Avoid using RTO_ONLINK with ip_route_connect().

2022-04-22T12:06:03+00:00

Now that ip_rt_fix_tos() doesn't reset ->flowi4_scope unconditionally, we don't have to rely on the RTO_ONLINK bit to properly set the scope of a flowi4 structure. We can just set ->flowi4_scope explicitly and avoid using RTO_ONLINK in ->flowi4_tos. This patch converts callers of ip_route_connect(). Instead of setting the tos parameter with RT_CONN_FLAGS(sk), as all callers do, we can: 1- Drop the tos parameter from ip_route_connect(): its value was entirely based on sk, which is also passed as parameter. 2- Set ->flowi4_scope depending on the SOCK_LOCALROUTE socket option instead of always initialising it with RT_SCOPE_UNIVERSE (let's define ip_sock_rt_scope() for this purpose). 3- Avoid overloading ->flowi4_tos with RTO_ONLINK: since the scope is now properly initialised, we don't need to tell ip_rt_fix_tos() to adjust ->flowi4_scope for us. So let's define ip_sock_rt_tos(), which is the same as RT_CONN_FLAGS() but without the RTO_ONLINK bit overload. Note: In the original ip_route_connect() code, __ip_route_output_key() might clear the RTO_ONLINK bit of fl4->flowi4_tos (because of ip_rt_fix_tos()). Therefore flowi4_update_output() had to reuse the original tos variable. Now that we don't set RTO_ONLINK any more, this is not a problem and we can use fl4->flowi4_tos in flowi4_update_output(). Signed-off-by: Guillaume Nault Reviewed-by: David Ahern Signed-off-by: David S. Miller

ipv4: remove sparse error in ip_neigh_gw4()

2022-01-27T16:38:33+00:00

./include/net/route.h:373:48: warning: incorrect type in argument 2 (different base types) ./include/net/route.h:373:48: expected unsigned int [usertype] key ./include/net/route.h:373:48: got restricted __be32 [usertype] daddr Fixes: 5c9f7c1dfc2e ("ipv4: Add helpers for neigh lookup for nexthop") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20220127013404.1279313-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski