tcp: annotate data-races around tp->notsent_lowat

stable inclusion
from stable-v5.10.188
commit 3cf0a0f11d39e183000df4ce090409181834b677
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8KYFP

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3cf0a0f11d39e183000df4ce090409181834b677



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[ Upstream commit 1aeb87bc ]

tp->notsent_lowat can be read locklessly from do_tcp_getsockopt()
and tcp_poll().

Fixes: c9bee3b7 ("tcp: TCP_NOTSENT_LOWAT socket option")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-10-edumazet@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>