Re: [PATCH 4.19-stable 1/3] tcp: annotate tp->copied_seq lockless reads

On Fri, Mar 12, 2021 at 12:33:21AM -0800, Eric Dumazet wrote:

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 7db48e983930285b765743ebd665aecf9850582b ]

There are few places where we fetch tp->copied_seq while
this field can change from IRQ or other cpu.

We need to add READ_ONCE() annotations, and also make
sure write sides use corresponding WRITE_ONCE() to avoid
store-tearing.

Note that tcp_inq_hint() was already using READ_ONCE(tp->copied_seq)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

All now queued up, thanks!

greg k-h