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![]() When sending multicast messages via blocking socket, if sending link is congested (tsk->cong_link_cnt is set to 1), the sending thread will be put into sleeping state. However, tipc_sk_filter_rcv() is called under socket spin lock but tipc_wait_for_cond() is not. So, there is no guarantee that the setting of tsk->cong_link_cnt to 0 in tipc_sk_proto_rcv() in CPU-1 will be perceived by CPU-0. If that is the case, the sending thread in CPU-0 after being waken up, will continue to see tsk->cong_link_cnt as 1 and put the sending thread into sleeping state again. The sending thread will sleep forever. CPU-0 | CPU-1 tipc_wait_for_cond() | { | // condition_ = !tsk->cong_link_cnt | while ((rc_ = !(condition_))) { | ... | release_sock(sk_); | wait_woken(); | | if (!sock_owned_by_user(sk)) | tipc_sk_filter_rcv() | { | ... | tipc_sk_proto_rcv() | { | ... | tsk->cong_link_cnt--; | ... | sk->sk_write_space(sk); | ... | } | ... | } sched_annotate_sleep(); | lock_sock(sk_); | remove_wait_queue(); | } | } | This commit fixes it by adding memory barrier to tipc_sk_proto_rcv() and tipc_wait_for_cond(). Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> |
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.. | ||
addr.c | ||
addr.h | ||
bcast.c | ||
bcast.h | ||
bearer.c | ||
bearer.h | ||
core.c | ||
core.h | ||
diag.c | ||
discover.c | ||
discover.h | ||
eth_media.c | ||
group.c | ||
group.h | ||
ib_media.c | ||
Kconfig | ||
link.c | ||
link.h | ||
Makefile | ||
monitor.c | ||
monitor.h | ||
msg.c | ||
msg.h | ||
name_distr.c | ||
name_distr.h | ||
name_table.c | ||
name_table.h | ||
net.c | ||
net.h | ||
netlink.c | ||
netlink.h | ||
netlink_compat.c | ||
node.c | ||
node.h | ||
socket.c | ||
socket.h | ||
subscr.c | ||
subscr.h | ||
sysctl.c | ||
topsrv.c | ||
topsrv.h | ||
trace.c | ||
trace.h | ||
udp_media.c | ||
udp_media.h |