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sock: annotate data-races around prot->memory_pressure

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*prot->memory_pressure is read/writen locklessly, we need
to add proper annotations.

A recent commit added a new race, it is time to audit all accesses.

Fixes: 2d0c88e84e ("sock: Fix misuse of sk_under_memory_pressure()")
Fixes: 4d93df0abd ("[SCTP]: Rewrite of sctp buffer management code")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Abel Wu <wuyun.abel@bytedance.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Link: https://lore.kernel.org/r/20230818015132.2699348-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Eric Dumazet 2023-08-18 01:51:32 +00:00 committed by Jakub Kicinski
parent d44036cad3
commit 76f33296d2
2 changed files with 5 additions and 4 deletions
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7
include/net/sock.h
View File

@ -1323,6 +1323,7 @@ struct proto {
/*
* Pressure flag: try to collapse.
* Technical note: it is used by multiple contexts non atomically.
* Make sure to use READ_ONCE()/WRITE_ONCE() for all reads/writes.
* All the __sk_mem_schedule() is of this nature: accounting
* is strict, actions are advisory and have some latency.
*/
@ -1423,7 +1424,7 @@ static inline bool sk_has_memory_pressure(const struct sock *sk)
static inline bool sk_under_global_memory_pressure(const struct sock *sk)
{
return sk->sk_prot->memory_pressure &&
!!*sk->sk_prot->memory_pressure;
!!READ_ONCE(*sk->sk_prot->memory_pressure);
}
static inline bool sk_under_memory_pressure(const struct sock *sk)
@ -1435,7 +1436,7 @@ static inline bool sk_under_memory_pressure(const struct sock *sk)
mem_cgroup_under_socket_pressure(sk->sk_memcg))
return true;
return !!*sk->sk_prot->memory_pressure;
return !!READ_ONCE(*sk->sk_prot->memory_pressure);
}
static inline long
@ -1512,7 +1513,7 @@ proto_memory_pressure(struct proto *prot)
{
if (!prot->memory_pressure)
return false;
return !!*prot->memory_pressure;
return !!READ_ONCE(*prot->memory_pressure);
}

2
net/sctp/socket.c
View File

@ -99,7 +99,7 @@ struct percpu_counter sctp_sockets_allocated;
static void sctp_enter_memory_pressure(struct sock *sk)
{
sctp_memory_pressure = 1;
WRITE_ONCE(sctp_memory_pressure, 1);
}