[ Upstream commit
1f142c17d19a5618d5a633195a46f2c8be9bf232 ]
tcp_memory_pressure is read without holding any lock,
and its value could be changed on other cpus.
Use READ_ONCE() to annotate these lockless reads.
The write side is already using atomic ops.
Fixes:
b8da51ebb1aa ("tcp: introduce tcp_under_memory_pressure()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
mem_cgroup_under_socket_pressure(sk->sk_memcg))
return true;
mem_cgroup_under_socket_pressure(sk->sk_memcg))
return true;
- return tcp_memory_pressure;
+ return READ_ONCE(tcp_memory_pressure);
}
/*
* The next routines deal with comparing 32 bit unsigned ints
}
/*
* The next routines deal with comparing 32 bit unsigned ints
- if (tcp_memory_pressure)
+ if (READ_ONCE(tcp_memory_pressure))
- if (!tcp_memory_pressure)
+ if (!READ_ONCE(tcp_memory_pressure))
return;
val = xchg(&tcp_memory_pressure, 0);
if (val)
return;
val = xchg(&tcp_memory_pressure, 0);
if (val)