From: Eric Dumazet edumazet@google.com
[ Upstream commit 503978aca46124cd714703e180b9c8292ba50ba7 ]
As mentioned in https://github.com/google/ktsan/wiki/READ_ONCE-and-WRITE_ONCE#it-may-improve... a C compiler can legally transform :
if (memory_pressure && *memory_pressure) *memory_pressure = 0;
to :
if (memory_pressure) *memory_pressure = 0;
Fixes: 0604475119de ("tcp: add TCPMemoryPressuresChrono counter") Fixes: 180d8cd942ce ("foundations of per-cgroup memory pressure controlling.") Fixes: 3ab224be6d69 ("[NET] CORE: Introducing new memory accounting interface.") 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 --- net/core/sock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/core/sock.c b/net/core/sock.c index bbde5f6a7dc9..b9ec14f2c729 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2179,8 +2179,8 @@ static void sk_leave_memory_pressure(struct sock *sk) } else { unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
- if (memory_pressure && *memory_pressure) - *memory_pressure = 0; + if (memory_pressure && READ_ONCE(*memory_pressure)) + WRITE_ONCE(*memory_pressure, 0); } }