xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

tcp: annotate sk->sk_rcvbuf lockless reads

Browse Source 
For the sake of tcp_poll(), there are few places where we fetch
sk->sk_rcvbuf 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 other transports probably need similar fixes.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2019-10-10 20:17:44 -07:00
committed by David S. Miller
parent d9b55bf7b6
commit ebb3b78db7
7 changed files with 15 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
include/net/tcp.h
View File

@@ -1380,14 +1380,14 @@ static inline int tcp_win_from_space(const struct sock *sk, int space)
/* Note: caller must be prepared to deal with negative returns */
static inline int tcp_space(const struct sock *sk)
{
return tcp_win_from_space(sk, sk->sk_rcvbuf -
return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) -
READ_ONCE(sk->sk_backlog.len) -
atomic_read(&sk->sk_rmem_alloc));
}
static inline int tcp_full_space(const struct sock *sk)
{
return tcp_win_from_space(sk, sk->sk_rcvbuf);
return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf));
}
extern void tcp_openreq_init_rwin(struct request_sock *req,