kernel.git/net/dccp/proto.c, branch linux-5.18.y

dccp: put dccp_qpolicy_full() and dccp_qpolicy_push() in the same lock

2022-08-17T12:41:16Z

[ Upstream commit a41b17ff9dacd22f5f118ee53d82da0f3e52d5e3 ] In the case of sk->dccps_qpolicy == DCCPQ_POLICY_PRIO, dccp_qpolicy_full will drop a skb when qpolicy is full. And the lock in dccp_sendmsg is released before sock_alloc_send_skb and then relocked after sock_alloc_send_skb. The following conditions may lead dccp_qpolicy_push to add skb to an already full sk_write_queue: thread1--->lock thread1--->dccp_qpolicy_full: queue is full. drop a skb thread1--->unlock thread2--->lock thread2--->dccp_qpolicy_full: queue is not full. no need to drop. thread2--->unlock thread1--->lock thread1--->dccp_qpolicy_push: add a skb. queue is full. thread1--->unlock thread2--->lock thread2--->dccp_qpolicy_push: add a skb! thread2--->unlock Fix this by moving dccp_qpolicy_full. Fixes: b1308dc015eb ("[DCCP]: Set TX Queue Length Bounds via Sysctl") Signed-off-by: Hangyu Hua Link: https://lore.kernel.org/r/20220729110027.40569-1-hbh25y@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

dccp: Inline dccp_listen_start().

2021-11-24T04:16:22Z

This patch inlines dccp_listen_start() and removes a stale comment in inet_dccp_listen() so that it looks like inet_listen(). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Richard Sailer Signed-off-by: Jakub Kicinski

dccp/tcp: Remove an unused argument in inet_csk_listen_start().

2021-11-24T04:16:18Z

The commit 1295e2cf3065 ("inet: minor optimization for backlog setting in listen(2)") added change so that sk_max_ack_backlog is initialised earlier in inet_dccp_listen() and inet_listen(). Since then, we no longer use backlog in inet_csk_listen_start(), so let's remove it. Signed-off-by: Kuniyuki Iwashima Acked-by: Yafang Shao Reviewed-by: Richard Sailer Signed-off-by: Jakub Kicinski

tcp: switch orphan_count to bare per-cpu counters

2021-10-15T10:28:34Z

Use of percpu_counter structure to track count of orphaned sockets is causing problems on modern hosts with 256 cpus or more. Stefan Bach reported a serious spinlock contention in real workloads, that I was able to reproduce with a netfilter rule dropping incoming FIN packets. 53.56% server [kernel.kallsyms] [k] queued_spin_lock_slowpath | ---queued_spin_lock_slowpath | --53.51%--_raw_spin_lock_irqsave | --53.51%--__percpu_counter_sum tcp_check_oom | |--39.03%--__tcp_close | tcp_close | inet_release | inet6_release | sock_close | __fput | ____fput | task_work_run | exit_to_usermode_loop | do_syscall_64 | entry_SYSCALL_64_after_hwframe | __GI___libc_close | --14.48%--tcp_out_of_resources tcp_write_timeout tcp_retransmit_timer tcp_write_timer_handler tcp_write_timer call_timer_fn expire_timers __run_timers run_timer_softirq __softirqentry_text_start As explained in commit cf86a086a180 ("net/dst: use a smaller percpu_counter batch for dst entries accounting"), default batch size is too big for the default value of tcp_max_orphans (262144). But even if we reduce batch sizes, there would still be cases where the estimated count of orphans is beyond the limit, and where tcp_too_many_orphans() has to call the expensive percpu_counter_sum_positive(). One solution is to use plain per-cpu counters, and have a timer to periodically refresh this cache. Updating this cache every 100ms seems about right, tcp pressure state is not radically changing over shorter periods. percpu_counter was nice 15 years ago while hosts had less than 16 cpus, not anymore by current standards. v2: Fix the build issue for CONFIG_CRYPTO_DEV_CHELSIO_TLS=m, reported by kernel test robot Remove unused socket argument from tcp_too_many_orphans() Fixes: dd24c00191d5 ("net: Use a percpu_counter for orphan_count") Signed-off-by: Eric Dumazet Reported-by: Stefan Bach Cc: Neal Cardwell Acked-by: Neal Cardwell Signed-off-by: David S. Miller

memcg: enable accounting for inet_bin_bucket cache

2021-07-20T13:00:38Z

net namespace can create up to 64K tcp and dccp ports and force kernel to allocate up to several megabytes of memory per netns for inet_bind_bucket objects. It makes sense to account for them to restrict the host's memory consumption from inside the memcg-limited container. Signed-off-by: Vasily Averin Signed-off-by: David S. Miller

net: sock: introduce sk_error_report

2021-06-29T18:28:21Z

This patch introduces a function wrapper to call the sk_error_report callback. That will prepare to add additional handling whenever sk_error_report is called, for example to trace socket errors. Signed-off-by: Alexander Aring Signed-off-by: David S. Miller

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59Z

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

net: remove sockptr_advance

2020-07-28T20:43:40Z

sockptr_advance never properly worked. Replace it with _offset variants of copy_from_sockptr and copy_to_sockptr. Fixes: ba423fdaa589 ("net: add a new sockptr_t type") Reported-by: Jason A. Donenfeld Reported-by: Ido Schimmel Signed-off-by: Christoph Hellwig Acked-by: Jason A. Donenfeld Tested-by: Ido Schimmel Signed-off-by: David S. Miller

net: pass a sockptr_t into ->setsockopt

2020-07-24T22:41:54Z

Rework the remaining setsockopt code to pass a sockptr_t instead of a plain user pointer. This removes the last remaining set_fs(KERNEL_DS) outside of architecture specific code. Signed-off-by: Christoph Hellwig Acked-by: Stefan Schmidt [ieee802154] Acked-by: Matthieu Baerts Signed-off-by: David S. Miller

net: dccp: Add SIOCOUTQ IOCTL support (send buffer fill)

2020-07-23T00:00:37Z

This adds support for the SIOCOUTQ IOCTL to get the send buffer fill of a DCCP socket, like UDP and TCP sockets already have. Regarding the used data field: DCCP uses per packet sequence numbers, not per byte, so sequence numbers can't be used like in TCP. sk_wmem_queued is not used by DCCP and always 0, even in test on highly congested paths. Therefore this uses sk_wmem_alloc like in UDP. Signed-off-by: Richard Sailer Signed-off-by: David S. Miller