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* net/smc: Send out the remaining data in sndbuf before closeWen Gu2022-03-291-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current autocork algorithms will delay the data transmission in BH context to smc_release_cb() when sock_lock is hold by user. So there is a possibility that when connection is being actively closed (sock_lock is hold by user now), some corked data still remains in sndbuf, waiting to be sent by smc_release_cb(). This will cause: - smc_close_stream_wait(), which is called under the sock_lock, has a high probability of timeout because data transmission is delayed until sock_lock is released. - Unexpected data sends may happen after connction closed and use the rtoken which has been deleted by remote peer through LLC_DELETE_RKEY messages. So this patch will try to send out the remaining corked data in sndbuf before active close process, to ensure data integrity and avoid unexpected data transmission after close. Reported-by: Guangguan Wang <guangguan.wang@linux.alibaba.com> Fixes: 6b88af839d20 ("net/smc: don't send in the BH context if sock_owned_by_user") Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Link: https://lore.kernel.org/r/1648447836-111521-1-git-send-email-guwen@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net/smc: fix a memory leak in smc_sysctl_net_exit()Eric Dumazet2022-03-261-0/+5
| | | | | | | | | | | | | Recently added smc_sysctl_net_exit() forgot to free the memory allocated from smc_sysctl_net_init() for non initial network namespace. Fixes: 462791bbfa35 ("net/smc: add sysctl interface for SMC") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Tony Lu <tonylu@linux.alibaba.com> Cc: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: fix -Wmissing-prototypes warning when CONFIG_SYSCTL not setDust Li2022-03-101-2/+2
| | | | | | | | | | | | | | | when CONFIG_SYSCTL not set, smc_sysctl_net_init/exit need to be static inline to avoid missing-prototypes if compile with W=1. Since __net_exit has noinline annotation when CONFIG_NET_NS not set, it should not be used with static inline. So remove the __net_init/exit when CONFIG_SYSCTL not set. Fixes: 7de8eb0d9039 ("net/smc: fix compile warning for smc_sysctl") Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Link: https://lore.kernel.org/r/20220309033051.41893-1-dust.li@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net/smc: fix compile warning for smc_sysctlDust Li2022-03-074-31/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernel test robot reports multiple warning for smc_sysctl: In file included from net/smc/smc_sysctl.c:17: >> net/smc/smc_sysctl.h:23:5: warning: no previous prototype \ for function 'smc_sysctl_init' [-Wmissing-prototypes] int smc_sysctl_init(void) ^ and >> WARNING: modpost: vmlinux.o(.text+0x12ced2d): Section mismatch \ in reference from the function smc_sysctl_exit() to the variable .init.data:smc_sysctl_ops The function smc_sysctl_exit() references the variable __initdata smc_sysctl_ops. This is often because smc_sysctl_exit lacks a __initdata annotation or the annotation of smc_sysctl_ops is wrong. and net/smc/smc_sysctl.c: In function 'smc_sysctl_init_net': net/smc/smc_sysctl.c:47:17: error: 'struct netns_smc' has no member named 'smc_hdr' 47 | net->smc.smc_hdr = register_net_sysctl(net, "net/smc", table); Since we don't need global sysctl initialization. To make things clean and simple, remove the global pernet_operations and smc_sysctl_{init|exit}. Call smc_sysctl_net_{init|exit} directly from smc_net_{init|exit}. Also initialized sysctl_autocorking_size if CONFIG_SYSCTL it not set, this make sure SMC autocorking is enabled by default if CONFIG_SYSCTL is not set. Fixes: 462791bbfa35 ("net/smc: add sysctl interface for SMC") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Signed-off-by: David S. Miller <davem@davemloft.net>
* Revert "net/smc: don't req_notify until all CQEs drained"Dust Li2022-03-061-28/+21
| | | | | | | | | | | | | | | | | | | | | This reverts commit a505cce6f7cfaf2aa2385aab7286063c96444526. Leon says: We already discussed that. SMC should be changed to use RDMA CQ pool API drivers/infiniband/core/cq.c. ib_poll_handler() has much better implementation (tracing, IRQ rescheduling, proper error handling) than this SMC variant. Since we will switch to ib_poll_handler() in the future, revert this patch. Link: https://lore.kernel.org/netdev/20220301105332.GA9417@linux.alibaba.com/ Suggested-by: Leon Romanovsky <leon@kernel.org> Suggested-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Reviewed-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-03-032-5/+14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | net/batman-adv/hard-interface.c commit 690bb6fb64f5 ("batman-adv: Request iflink once in batadv-on-batadv check") commit 6ee3c393eeb7 ("batman-adv: Demote batadv-on-batadv skip error message") https://lore.kernel.org/all/20220302163049.101957-1-sw@simonwunderlich.de/ net/smc/af_smc.c commit 4d08b7b57ece ("net/smc: Fix cleanup when register ULP fails") commit 462791bbfa35 ("net/smc: add sysctl interface for SMC") https://lore.kernel.org/all/20220302112209.355def40@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error cause by serverD. Wythe2022-03-031-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The problem of SMC_CLC_DECL_ERR_REGRMB on the server is very clear. Based on the fact that whether a new SMC connection can be accepted or not depends on not only the limit of conn nums, but also the available entries of rtoken. Since the rtoken release is trigger by peer, while the conn nums is decrease by local, tons of thing can happen in this time difference. This only thing that needs to be mentioned is that now all connection creations are completely protected by smc_server_lgr_pending lock, it's enough to check only the available entries in rtokens_used_mask. Fixes: cd6851f30386 ("smc: remote memory buffers (RMBs)") Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error generated by clientD. Wythe2022-03-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The main reason for this unexpected SMC_CLC_DECL_ERR_REGRMB in client dues to following execution sequence: Server Conn A: Server Conn B: Client Conn B: smc_lgr_unregister_conn smc_lgr_register_conn smc_clc_send_accept -> smc_rtoken_add smcr_buf_unuse -> Client Conn A: smc_rtoken_delete smc_lgr_unregister_conn() makes current link available to assigned to new incoming connection, while smcr_buf_unuse() has not executed yet, which means that smc_rtoken_add may fail because of insufficient rtoken_entry, reversing their execution order will avoid this problem. Fixes: 3e034725c0d8 ("net/smc: common functions for RMBs and send buffers") Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * net/smc: Fix cleanup when register ULP failsTony Lu2022-02-281-1/+3
| | | | | | | | | | | | | | | | | | This patch calls smc_ib_unregister_client() when tcp_register_ulp() fails, and make sure to clean it up. Fixes: d7cd421da9da ("net/smc: Introduce TCP ULP support") Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * net/smc: fix connection leakD. Wythe2022-02-251-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a potential leak issue under following execution sequence : smc_release smc_connect_work if (sk->sk_state == SMC_INIT) send_clc_confirim tcp_abort(); ... sk.sk_state = SMC_ACTIVE smc_close_active switch(sk->sk_state) { ... case SMC_ACTIVE: smc_close_final() // then wait peer closed Unfortunately, tcp_abort() may discard CLC CONFIRM messages that are still in the tcp send buffer, in which case our connection token cannot be delivered to the server side, which means that we cannot get a passive close message at all. Therefore, it is impossible for the to be disconnected at all. This patch tries a very simple way to avoid this issue, once the state has changed to SMC_ACTIVE after tcp_abort(), we can actively abort the smc connection, considering that the state is SMC_INIT before tcp_abort(), abandoning the complete disconnection process should not cause too much problem. In fact, this problem may exist as long as the CLC CONFIRM message is not received by the server. Whether a timer should be added after smc_close_final() needs to be discussed in the future. But even so, this patch provides a faster release for connection in above case, it should also be valuable. Fixes: 39f41f367b08 ("net/smc: common release code for non-accepted sockets") Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: smc: fix different types in min()Jakub Kicinski2022-03-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix build: include/linux/minmax.h:45:25: note: in expansion of macro ‘__careful_cmp’ 45 | #define min(x, y) __careful_cmp(x, y, <) | ^~~~~~~~~~~~~ net/smc/smc_tx.c:150:24: note: in expansion of macro ‘min’ 150 | corking_size = min(sock_net(&smc->sk)->smc.sysctl_autocorking_size, | ^~~ Fixes: 12bbb0d163a9 ("net/smc: add sysctl for autocorking") Link: https://lore.kernel.org/r/20220301222446.1271127-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net/smc: don't send in the BH context if sock_owned_by_userDust Li2022-03-013-5/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Send data all the way down to the RDMA device is a time consuming operation(get a new slot, maybe do RDMA Write and send a CDC, etc). Moving those operations from BH to user context is good for performance. If the sock_lock is hold by user, we don't try to send data out in the BH context, but just mark we should send. Since the user will release the sock_lock soon, we can do the sending there. Add smc_release_cb() which will be called in release_sock() and try send in the callback if needed. This patch moves the sending part out from BH if sock lock is hold by user. In my testing environment, this saves about 20% softirq in the qperf 4K tcp_bw test in the sender side with no noticeable throughput drop. Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: don't req_notify until all CQEs drainedDust Li2022-03-011-21/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we are handling softirq workload, enable hardirq may again interrupt the current routine of softirq, and then try to raise softirq again. This only wastes CPU cycles and won't have any real gain. Since IB_CQ_REPORT_MISSED_EVENTS already make sure if ib_req_notify_cq() returns 0, it is safe to wait for the next event, with no need to poll the CQ again in this case. This patch disables hardirq during the processing of softirq, and re-arm the CQ after softirq is done. Somehow like NAPI. Co-developed-by: Guangguan Wang <guangguan.wang@linux.alibaba.com> Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com> Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: correct settings of RMB window update limitDust Li2022-03-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rmbe_update_limit is used to limit announcing receive window updating too frequently. RFC7609 request a minimal increase in the window size of 10% of the receive buffer space. But current implementation used: min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2) and SOCK_MIN_SNDBUF / 2 == 2304 Bytes, which is almost always less then 10% of the receive buffer space. This causes the receiver always sending CDC message to update its consumer cursor when it consumes more then 2K of data. And as a result, we may encounter something like "TCP silly window syndrome" when sending 2.5~8K message. This patch fixes this using max(rmbe_size / 10, SOCK_MIN_SNDBUF / 2). With this patch and SMC autocorking enabled, qperf 2K/4K/8K tcp_bw test shows 45%/75%/40% increase in throughput respectively. Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: send directly on setting TCP_NODELAYDust Li2022-03-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit ea785a1a573b("net/smc: Send directly when TCP_CORK is cleared"), we don't use delayed work to implement cork. This patch use the same algorithm, removes the delayed work when setting TCP_NODELAY and send directly in setsockopt(). This also makes the TCP_NODELAY the same as TCP. Cc: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: add sysctl for autocorkingDust Li2022-03-012-1/+11
| | | | | | | | | | | | | | | | | | | | | | This add a new sysctl: net.smc.autocorking_size We can dynamically change the behaviour of autocorking by change the value of autocorking_size. Setting to 0 disables autocorking in SMC Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: add autocorking supportDust Li2022-03-013-15/+105
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds autocorking support for SMC which could improve throughput for small message by x3+. The main idea is borrowed from TCP autocorking with some RDMA specific modification: 1. The first message should never cork to make sure we won't bring extra latency 2. If we have posted any Tx WRs to the NIC that have not completed, cork the new messages until: a) Receive CQE for the last Tx WR b) We have corked enough message on the connection 3. Try to push the corked data out when we receive CQE of the last Tx WR to prevent the corked messages hang in the send queue. Both SMC autocorking and TCP autocorking check the TX completion to decide whether we should cork or not. The difference is when we got a SMC Tx WR completion, the data have been confirmed by the RNIC while TCP TX completion just tells us the data have been sent out by the local NIC. Add an atomic variable tx_pushing in smc_connection to make sure only one can send to let it cork more and save CDC slot. SMC autocorking should not bring extra latency since the first message will always been sent out immediately. The qperf tcp_bw test shows more than x4 increase under small message size with Mellanox connectX4-Lx, same result with other throughput benchmarks like sockperf/netperf. The qperf tcp_lat test shows SMC autocorking has not increase any ping-pong latency. Test command: client: smc_run taskset -c 1 qperf smc-server -oo msg_size:1:64K:*2 \ -t 30 -vu tcp_{bw|lat} server: smc_run taskset -c 1 qperf === Bandwidth ==== MsgSize(Bytes) SMC-NoCork TCP SMC-AutoCorking 1 0.578 MB/s 2.392 MB/s(313.57%) 2.647 MB/s(357.72%) 2 1.159 MB/s 4.780 MB/s(312.53%) 5.153 MB/s(344.71%) 4 2.283 MB/s 10.266 MB/s(349.77%) 10.363 MB/s(354.02%) 8 4.668 MB/s 19.040 MB/s(307.86%) 21.215 MB/s(354.45%) 16 9.147 MB/s 38.904 MB/s(325.31%) 41.740 MB/s(356.32%) 32 18.369 MB/s 79.587 MB/s(333.25%) 82.392 MB/s(348.52%) 64 36.562 MB/s 148.668 MB/s(306.61%) 161.564 MB/s(341.89%) 128 72.961 MB/s 274.913 MB/s(276.80%) 325.363 MB/s(345.94%) 256 144.705 MB/s 512.059 MB/s(253.86%) 633.743 MB/s(337.96%) 512 288.873 MB/s 884.977 MB/s(206.35%) 1250.681 MB/s(332.95%) 1024 574.180 MB/s 1337.736 MB/s(132.98%) 2246.121 MB/s(291.19%) 2048 1095.192 MB/s 1865.952 MB/s( 70.38%) 2057.767 MB/s( 87.89%) 4096 2066.157 MB/s 2380.337 MB/s( 15.21%) 2173.983 MB/s( 5.22%) 8192 3717.198 MB/s 2733.073 MB/s(-26.47%) 3491.223 MB/s( -6.08%) 16384 4742.221 MB/s 2958.693 MB/s(-37.61%) 4637.692 MB/s( -2.20%) 32768 5349.550 MB/s 3061.285 MB/s(-42.77%) 5385.796 MB/s( 0.68%) 65536 5162.919 MB/s 3731.408 MB/s(-27.73%) 5223.890 MB/s( 1.18%) ==== Latency ==== MsgSize(Bytes) SMC-NoCork TCP SMC-AutoCorking 1 10.540 us 11.938 us( 13.26%) 10.573 us( 0.31%) 2 10.996 us 11.992 us( 9.06%) 10.269 us( -6.61%) 4 10.229 us 11.687 us( 14.25%) 10.240 us( 0.11%) 8 10.203 us 11.653 us( 14.21%) 10.402 us( 1.95%) 16 10.530 us 11.313 us( 7.44%) 10.599 us( 0.66%) 32 10.241 us 11.586 us( 13.13%) 10.223 us( -0.18%) 64 10.693 us 11.652 us( 8.97%) 10.251 us( -4.13%) 128 10.597 us 11.579 us( 9.27%) 10.494 us( -0.97%) 256 10.409 us 11.957 us( 14.87%) 10.710 us( 2.89%) 512 11.088 us 12.505 us( 12.78%) 10.547 us( -4.88%) 1024 11.240 us 12.255 us( 9.03%) 10.787 us( -4.03%) 2048 11.485 us 16.970 us( 47.76%) 11.256 us( -1.99%) 4096 12.077 us 13.948 us( 15.49%) 12.230 us( 1.27%) 8192 13.683 us 16.693 us( 22.00%) 13.786 us( 0.75%) 16384 16.470 us 23.615 us( 43.38%) 16.459 us( -0.07%) 32768 22.540 us 40.966 us( 81.75%) 23.284 us( 3.30%) 65536 34.192 us 73.003 us(113.51%) 34.233 us( 0.12%) With SMC autocorking support, we can archive better throughput than TCP in most message sizes without any latency trade-off. Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: add sysctl interface for SMCDust Li2022-03-014-1/+113
| | | | | | | | | | | | | | | | | | | | | | This patch add sysctl interface to support container environment for SMC as we talk in the mail list. Link: https://lore.kernel.org/netdev/20220224020253.GF5443@linux.alibaba.com Co-developed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: Call trace_smc_tx_sendmsg when data corkedTony Lu2022-02-281-9/+8
| | | | | | | | | | | | | | | | | | | | | | This also calls trace_smc_tx_sendmsg() even if data is corked. For ease of understanding, if statements are not expanded here. Link: https://lore.kernel.org/all/f4166712-9a1e-51a0-409d-b7df25a66c52@linux.ibm.com/ Fixes: 139653bc6635 ("net/smc: Remove corked dealyed work") Suggested-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-02-252-22/+22
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tools/testing/selftests/net/mptcp/mptcp_join.sh 34aa6e3bccd8 ("selftests: mptcp: add ip mptcp wrappers") 857898eb4b28 ("selftests: mptcp: add missing join check") 6ef84b1517e0 ("selftests: mptcp: more robust signal race test") https://lore.kernel.org/all/20220221131842.468893-1-broonie@kernel.org/ drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/act.h drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/ct.c fb7e76ea3f3b6 ("net/mlx5e: TC, Skip redundant ct clear actions") c63741b426e11 ("net/mlx5e: Fix MPLSoUDP encap to use MPLS action information") 09bf97923224f ("net/mlx5e: TC, Move pedit_headers_action to parse_attr") 84ba8062e383 ("net/mlx5e: Test CT and SAMPLE on flow attr") efe6f961cd2e ("net/mlx5e: CT, Don't set flow flag CT for ct clear flow") 3b49a7edec1d ("net/mlx5e: TC, Reject rules with multiple CT actions") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net/smc: Use a mutex for locking "struct smc_pnettable"Fabio M. De Francesco2022-02-242-22/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | smc_pnetid_by_table_ib() uses read_lock() and then it calls smc_pnet_apply_ib() which, in turn, calls mutex_lock(&smc_ib_devices.mutex). read_lock() disables preemption. Therefore, the code acquires a mutex while in atomic context and it leads to a SAC bug. Fix this bug by replacing the rwlock with a mutex. Reported-and-tested-by: syzbot+4f322a6d84e991c38775@syzkaller.appspotmail.com Fixes: 64e28b52c7a6 ("net/smc: add pnet table namespace support") Confirmed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Link: https://lore.kernel.org/r/20220223100252.22562-1-fmdefrancesco@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net/smc: unlock on error paths in __smc_setsockopt()Dan Carpenter2022-02-191-4/+8
| | | | | | | | | | | | | | | | | | These two error paths need to release_sock(sk) before returning. Fixes: a6a6fe27bab4 ("net/smc: Dynamic control handshake limitation by socket options") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-02-171-3/+7
|\| | | | | | | | | | | No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net/smc: Avoid overwriting the copies of clcsock callback functionsWen Gu2022-02-111-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The callback functions of clcsock will be saved and replaced during the fallback. But if the fallback happens more than once, then the copies of these callback functions will be overwritten incorrectly, resulting in a loop call issue: clcsk->sk_error_report |- smc_fback_error_report() <------------------------------| |- smc_fback_forward_wakeup() | (loop) |- clcsock_callback() (incorrectly overwritten) | |- smc->clcsk_error_report() ------------------| So this patch fixes the issue by saving these function pointers only once in the fallback and avoiding overwriting. Reported-by: syzbot+4de3c0e8a263e1e499bc@syzkaller.appspotmail.com Fixes: 341adeec9ada ("net/smc: Forward wakeup to smc socket waitqueue after fallback") Link: https://lore.kernel.org/r/0000000000006d045e05d78776f6@google.com Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: return ETIMEDOUT when smc_connect_clc() timeoutD. Wythe2022-02-171-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When smc_connect_clc() times out, it will return -EAGAIN(tcp_recvmsg retuns -EAGAIN while timeout), then this value will passed to the application, which is quite confusing to the applications, makes inconsistency with TCP. From the manual of connect, ETIMEDOUT is more suitable, and this patch try convert EAGAIN to ETIMEDOUT in that case. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Reviewed-by: Karsten Graul <kgraul@linux.ibm.com> Link: https://lore.kernel.org/r/1644913490-21594-1-git-send-email-alibuda@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net/smc: Add comment for smc_tx_pendingTony Lu2022-02-141-1/+6
| | | | | | | | | | | | | | | | | | | | The previous patch introduces a lock-free version of smc_tx_work() to solve unnecessary lock contention, which is expected to be held lock. So this adds comment to remind people to keep an eye out for locks. Suggested-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: Add global configure for handshake limitation by netlinkD. Wythe2022-02-114-0/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Although we can control SMC handshake limitation through socket options, which means that applications who need it must modify their code. It's quite troublesome for many existing applications. This patch modifies the global default value of SMC handshake limitation through netlink, providing a way to put constraint on handshake without modifies any code for applications. Suggested-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: Dynamic control handshake limitation by socket optionsD. Wythe2022-02-112-1/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch aims to add dynamic control for SMC handshake limitation for every smc sockets, in production environment, it is possible for the same applications to handle different service types, and may have different opinion on SMC handshake limitation. This patch try socket options to complete it, since we don't have socket option level for SMC yet, which requires us to implement it at the same time. This patch does the following: - add new socket option level: SOL_SMC. - add new SMC socket option: SMC_LIMIT_HS. - provide getter/setter for SMC socket options. Link: https://lore.kernel.org/all/20f504f961e1a803f85d64229ad84260434203bd.1644323503.git.alibuda@linux.alibaba.com/ Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: Limit SMC visits when handshake workqueue congestedD. Wythe2022-02-111-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch intends to provide a mechanism to put constraint on SMC connections visit according to the pressure of SMC handshake process. At present, frequent visits will cause the incoming connections to be backlogged in SMC handshake queue, raise the connections established time. Which is quite unacceptable for those applications who base on short lived connections. There are two ways to implement this mechanism: 1. Put limitation after TCP established. 2. Put limitation before TCP established. In the first way, we need to wait and receive CLC messages that the client will potentially send, and then actively reply with a decline message, in a sense, which is also a sort of SMC handshake, affect the connections established time on its way. In the second way, the only problem is that we need to inject SMC logic into TCP when it is about to reply the incoming SYN, since we already do that, it's seems not a problem anymore. And advantage is obvious, few additional processes are required to complete the constraint. This patch use the second way. After this patch, connections who beyond constraint will not informed any SMC indication, and SMC will not be involved in any of its subsequent processes. Link: https://lore.kernel.org/all/1641301961-59331-1-git-send-email-alibuda@linux.alibaba.com/ Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: Limit backlog connectionsD. Wythe2022-02-112-1/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current implementation does not handling backlog semantics, one potential risk is that server will be flooded by infinite amount connections, even if client was SMC-incapable. This patch works to put a limit on backlog connections, referring to the TCP implementation, we divides SMC connections into two categories: 1. Half SMC connection, which includes all TCP established while SMC not connections. 2. Full SMC connection, which includes all SMC established connections. For half SMC connection, since all half SMC connections starts with TCP established, we can achieve our goal by put a limit before TCP established. Refer to the implementation of TCP, this limits will based on not only the half SMC connections but also the full connections, which is also a constraint on full SMC connections. For full SMC connections, although we know exactly where it starts, it's quite hard to put a limit before it. The easiest way is to block wait before receive SMC confirm CLC message, while it's under protection by smc_server_lgr_pending, a global lock, which leads this limit to the entire host instead of a single listen socket. Another way is to drop the full connections, but considering the cast of SMC connections, we prefer to keep full SMC connections. Even so, the limits of full SMC connections still exists, see commits about half SMC connection below. After this patch, the limits of backend connection shows like: For SMC: 1. Client with SMC-capability can makes 2 * backlog full SMC connections or 1 * backlog half SMC connections and 1 * backlog full SMC connections at most. 2. Client without SMC-capability can only makes 1 * backlog half TCP connections and 1 * backlog full TCP connections. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: Make smc_tcp_listen_work() independentD. Wythe2022-02-111-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In multithread and 10K connections benchmark, the backend TCP connection established very slowly, and lots of TCP connections stay in SYN_SENT state. Client: smc_run wrk -c 10000 -t 4 http://server the netstate of server host shows like: 145042 times the listen queue of a socket overflowed 145042 SYNs to LISTEN sockets dropped One reason of this issue is that, since the smc_tcp_listen_work() shared the same workqueue (smc_hs_wq) with smc_listen_work(), while the smc_listen_work() do blocking wait for smc connection established. Once the workqueue became congested, it's will block the accept() from TCP listen. This patch creates a independent workqueue(smc_tcp_ls_wq) for smc_tcp_listen_work(), separate it from smc_listen_work(), which is quite acceptable considering that smc_tcp_listen_work() runs very fast. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-02-111-3/+5
|\| | | | | | | | | | | No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net/smc: use GFP_ATOMIC allocation in smc_pnet_add_eth()Eric Dumazet2022-02-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | My last patch moved the netdev_tracker_alloc() call to a section protected by a write_lock(). I should have replaced GFP_KERNEL with GFP_ATOMIC to avoid the infamous: BUG: sleeping function called from invalid context at include/linux/sched/mm.h:256 Fixes: 28f922213886 ("net/smc: fix ref_tracker issue in smc_pnet_add()") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * net/smc: fix ref_tracker issue in smc_pnet_add()Eric Dumazet2022-02-061-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I added the netdev_tracker_alloc() right after ndev was stored into the newly allocated object: new_pe->ndev = ndev; if (ndev) netdev_tracker_alloc(ndev, &new_pe->dev_tracker, GFP_KERNEL); But I missed that later, we could end up freeing new_pe, then calling dev_put(ndev) to release the reference on ndev. The new_pe->dev_tracker would not be freed. To solve this issue, move the netdev_tracker_alloc() call to the point we know for sure new_pe will be kept. syzbot report (on net-next tree, but the bug is present in net tree) WARNING: CPU: 0 PID: 6019 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31 Modules linked in: CPU: 0 PID: 6019 Comm: syz-executor.3 Not tainted 5.17.0-rc2-syzkaller-00650-g5a8fb33e5305 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31 Code: 1d f4 70 a0 09 31 ff 89 de e8 4d bc 99 fd 84 db 75 e0 e8 64 b8 99 fd 48 c7 c7 20 0c 06 8a c6 05 d4 70 a0 09 01 e8 9e 4e 28 05 <0f> 0b eb c4 e8 48 b8 99 fd 0f b6 1d c3 70 a0 09 31 ff 89 de e8 18 RSP: 0018:ffffc900043b7400 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff815fb318 RDI: fffff52000876e72 RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815f507e R11: 0000000000000000 R12: 1ffff92000876e85 R13: 0000000000000000 R14: ffff88805c1c6600 R15: 0000000000000000 FS: 00007f1ef6feb700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d02b000 CR3: 00000000223f4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __refcount_dec include/linux/refcount.h:344 [inline] refcount_dec include/linux/refcount.h:359 [inline] ref_tracker_free+0x53f/0x6c0 lib/ref_tracker.c:119 netdev_tracker_free include/linux/netdevice.h:3867 [inline] dev_put_track include/linux/netdevice.h:3884 [inline] dev_put_track include/linux/netdevice.h:3880 [inline] dev_put include/linux/netdevice.h:3910 [inline] smc_pnet_add_eth net/smc/smc_pnet.c:399 [inline] smc_pnet_enter net/smc/smc_pnet.c:493 [inline] smc_pnet_add+0x5fc/0x15f0 net/smc/smc_pnet.c:556 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:731 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Fixes: b60645248af3 ("net/smc: add net device tracker to struct smc_pnetentry") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-02-043-18/+137
|\| | | | | | | | | | | No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * Partially revert "net/smc: Add netlink net namespace support"Dmitry V. Levin2022-02-021-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The change of sizeof(struct smc_diag_linkinfo) by commit 79d39fc503b4 ("net/smc: Add netlink net namespace support") introduced an ABI regression: since struct smc_diag_lgrinfo contains an object of type "struct smc_diag_linkinfo", offset of all subsequent members of struct smc_diag_lgrinfo was changed by that change. As result, applications compiled with the old version of struct smc_diag_linkinfo will receive garbage in struct smc_diag_lgrinfo.role if the kernel implements this new version of struct smc_diag_linkinfo. Fix this regression by reverting the part of commit 79d39fc503b4 that changes struct smc_diag_linkinfo. After all, there is SMC_GEN_NETLINK interface which is good enough, so there is probably no need to touch the smc_diag ABI in the first place. Fixes: 79d39fc503b4 ("net/smc: Add netlink net namespace support") Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Reviewed-by: Karsten Graul <kgraul@linux.ibm.com> Link: https://lore.kernel.org/r/20220202030904.GA9742@altlinux.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net/smc: Forward wakeup to smc socket waitqueue after fallbackWen Gu2022-01-312-16/+137
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we replace TCP with SMC and a fallback occurs, there may be some socket waitqueue entries remaining in smc socket->wq, such as eppoll_entries inserted by userspace applications. After the fallback, data flows over TCP/IP and only clcsocket->wq will be woken up. Applications can't be notified by the entries which were inserted in smc socket->wq before fallback. So we need a mechanism to wake up smc socket->wq at the same time if some entries remaining in it. The current workaround is to transfer the entries from smc socket->wq to clcsock->wq during the fallback. But this may cause a crash like this: general protection fault, probably for non-canonical address 0xdead000000000100: 0000 [#1] PREEMPT SMP PTI CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Tainted: G E 5.16.0+ #107 RIP: 0010:__wake_up_common+0x65/0x170 Call Trace: <IRQ> __wake_up_common_lock+0x7a/0xc0 sock_def_readable+0x3c/0x70 tcp_data_queue+0x4a7/0xc40 tcp_rcv_established+0x32f/0x660 ? sk_filter_trim_cap+0xcb/0x2e0 tcp_v4_do_rcv+0x10b/0x260 tcp_v4_rcv+0xd2a/0xde0 ip_protocol_deliver_rcu+0x3b/0x1d0 ip_local_deliver_finish+0x54/0x60 ip_local_deliver+0x6a/0x110 ? tcp_v4_early_demux+0xa2/0x140 ? tcp_v4_early_demux+0x10d/0x140 ip_sublist_rcv_finish+0x49/0x60 ip_sublist_rcv+0x19d/0x230 ip_list_rcv+0x13e/0x170 __netif_receive_skb_list_core+0x1c2/0x240 netif_receive_skb_list_internal+0x1e6/0x320 napi_complete_done+0x11d/0x190 mlx5e_napi_poll+0x163/0x6b0 [mlx5_core] __napi_poll+0x3c/0x1b0 net_rx_action+0x27c/0x300 __do_softirq+0x114/0x2d2 irq_exit_rcu+0xb4/0xe0 common_interrupt+0xba/0xe0 </IRQ> <TASK> The crash is caused by privately transferring waitqueue entries from smc socket->wq to clcsock->wq. The owners of these entries, such as epoll, have no idea that the entries have been transferred to a different socket wait queue and still use original waitqueue spinlock (smc socket->wq.wait.lock) to make the entries operation exclusive, but it doesn't work. The operations to the entries, such as removing from the waitqueue (now is clcsock->wq after fallback), may cause a crash when clcsock waitqueue is being iterated over at the moment. This patch tries to fix this by no longer transferring wait queue entries privately, but introducing own implementations of clcsock's callback functions in fallback situation. The callback functions will forward the wakeup to smc socket->wq if clcsock->wq is actually woken up and smc socket->wq has remaining entries. Fixes: 2153bd1e3d3d ("net/smc: Transfer remaining wait queue entries during fallback") Suggested-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: Cork when sendpage with MSG_SENDPAGE_NOTLAST flagTony Lu2022-01-313-2/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This introduces a new corked flag, MSG_SENDPAGE_NOTLAST, which is involved in syscall sendfile() [1], it indicates this is not the last page. So we can cork the data until the page is not specify this flag. It has the same effect as MSG_MORE, but existed in sendfile() only. This patch adds a option MSG_SENDPAGE_NOTLAST for corking data, try to cork more data before sending when using sendfile(), which acts like TCP's behaviour. Also, this reimplements the default sendpage to inform that it is supported to some extent. [1] https://man7.org/linux/man-pages/man2/sendfile.2.html Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: Remove corked dealyed workTony Lu2022-01-311-9/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on the manual of TCP_CORK [1] and MSG_MORE [2], these two options have the same effect. Applications can set these options and informs the kernel to pend the data, and send them out only when the socket or syscall does not specify this flag. In other words, there's no need to send data out by a delayed work, which will queue a lot of work. This removes corked delayed work with SMC_TX_CORK_DELAY (250ms), and the applications control how/when to send them out. It improves the performance for sendfile and throughput, and remove unnecessary race of lock_sock(). This also unlocks the limitation of sndbuf, and try to fill it up before sending. [1] https://linux.die.net/man/7/tcp [2] https://man7.org/linux/man-pages/man2/send.2.html Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: Send directly when TCP_CORK is clearedTony Lu2022-01-313-12/+18
|/ | | | | | | | | | | | | | | | | | | | | According to the man page of TCP_CORK [1], if set, don't send out partial frames. All queued partial frames are sent when option is cleared again. When applications call setsockopt to disable TCP_CORK, this call is protected by lock_sock(), and tries to mod_delayed_work() to 0, in order to send pending data right now. However, the delayed work smc_tx_work is also protected by lock_sock(). There introduces lock contention for sending data. To fix it, send pending data directly which acts like TCP, without lock_sock() protected in the context of setsockopt (already lock_sock()ed), and cancel unnecessary dealyed work, which is protected by lock. [1] https://linux.die.net/man/7/tcp Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: Transitional solution for clcsock race issueWen Gu2022-01-241-12/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We encountered a crash in smc_setsockopt() and it is caused by accessing smc->clcsock after clcsock was released. BUG: kernel NULL pointer dereference, address: 0000000000000020 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 50309 Comm: nginx Kdump: loaded Tainted: G E 5.16.0-rc4+ #53 RIP: 0010:smc_setsockopt+0x59/0x280 [smc] Call Trace: <TASK> __sys_setsockopt+0xfc/0x190 __x64_sys_setsockopt+0x20/0x30 do_syscall_64+0x34/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f16ba83918e </TASK> This patch tries to fix it by holding clcsock_release_lock and checking whether clcsock has already been released before access. In case that a crash of the same reason happens in smc_getsockopt() or smc_switch_to_fallback(), this patch also checkes smc->clcsock in them too. And the caller of smc_switch_to_fallback() will identify whether fallback succeeds according to the return value. Fixes: fd57770dd198 ("net/smc: wait for pending work before clcsock release_sock") Link: https://lore.kernel.org/lkml/5dd7ffd1-28e2-24cc-9442-1defec27375e@linux.ibm.com/T/ Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: Fix hung_task when removing SMC-R devicesWen Gu2022-01-161-16/+1
| | | | | | | | | | | | | | | | | | | | | | A hung_task is observed when removing SMC-R devices. Suppose that a link group has two active links(lnk_A, lnk_B) associated with two different SMC-R devices(dev_A, dev_B). When dev_A is removed, the link group will be removed from smc_lgr_list and added into lgr_linkdown_list. lnk_A will be cleared and smcibdev(A)->lnk_cnt will reach to zero. However, when dev_B is removed then, the link group can't be found in smc_lgr_list and lnk_B won't be cleared, making smcibdev->lnk_cnt never reaches zero, which causes a hung_task. This patch fixes this issue by restoring the implementation of smc_smcr_terminate_all() to what it was before commit 349d43127dac ("net/smc: fix kernel panic caused by race of smc_sock"). The original implementation also satisfies the intention that make sure QP destroy earlier than CQ destroy because we will always wait for smcibdev->lnk_cnt reaches zero, which guarantees QP has been destroyed. Fixes: 349d43127dac ("net/smc: fix kernel panic caused by race of smc_sock") Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: Remove unused function declarationWen Gu2022-01-151-4/+0
| | | | | | | | | | The declaration of smc_wr_tx_dismiss_slots() is unused. So remove it. Fixes: 349d43127dac ("net/smc: fix kernel panic caused by race of smc_sock") Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Reviewed-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: Resolve the race between SMC-R link access and clearWen Gu2022-01-132-12/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We encountered some crashes caused by the race between SMC-R link access and link clear that triggered by abnormal link group termination, such as port error. Here is an example of this kind of crashes: BUG: kernel NULL pointer dereference, address: 0000000000000000 Workqueue: smc_hs_wq smc_listen_work [smc] RIP: 0010:smc_llc_flow_initiate+0x44/0x190 [smc] Call Trace: <TASK> ? __smc_buf_create+0x75a/0x950 [smc] smcr_lgr_reg_rmbs+0x2a/0xbf [smc] smc_listen_work+0xf72/0x1230 [smc] ? process_one_work+0x25c/0x600 process_one_work+0x25c/0x600 worker_thread+0x4f/0x3a0 ? process_one_work+0x600/0x600 kthread+0x15d/0x1a0 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x1f/0x30 </TASK> smc_listen_work() __smc_lgr_terminate() --------------------------------------------------------------- | smc_lgr_free() | |- smcr_link_clear() | |- memset(lnk, 0) smc_listen_rdma_reg() | |- smcr_lgr_reg_rmbs() | |- smc_llc_flow_initiate() | |- access lnk->lgr (panic) | These crashes are similarly caused by clearing SMC-R link resources when some functions is still accessing to them. This patch tries to fix the issue by introducing reference count of SMC-R links and ensuring that the sensitive resources of links won't be cleared until reference count reaches zero. The operation to the SMC-R link reference count can be concluded as follows: object [hold or initialized as 1] [put] -------------------------------------------------------------------- links smcr_link_init() smcr_link_clear() connections smc_conn_create() smc_conn_free() Through this way, the clear of SMC-R links is later than the free of all the smc connections above it, thus avoiding the unsafe reference to SMC-R links. Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: Introduce a new conn->lgr validity check helperWen Gu2022-01-136-12/+24
| | | | | | | | | | | | | | It is no longer suitable to identify whether a smc connection is registered in a link group through checking if conn->lgr is NULL, because conn->lgr won't be reset even the connection is unregistered from a link group. So this patch introduces a new helper smc_conn_lgr_valid() and replaces all the check of conn->lgr in original implementation with the new helper to judge if conn->lgr is valid to use. Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: Resolve the race between link group access and terminationWen Gu2022-01-133-11/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We encountered some crashes caused by the race between the access and the termination of link groups. Here are some of panic stacks we met: 1) Race between smc_clc_wait_msg() and __smc_lgr_terminate() BUG: kernel NULL pointer dereference, address: 00000000000002f0 Workqueue: smc_hs_wq smc_listen_work [smc] RIP: 0010:smc_clc_wait_msg+0x3eb/0x5c0 [smc] Call Trace: <TASK> ? smc_clc_send_accept+0x45/0xa0 [smc] ? smc_clc_send_accept+0x45/0xa0 [smc] smc_listen_work+0x783/0x1220 [smc] ? finish_task_switch+0xc4/0x2e0 ? process_one_work+0x1ad/0x3c0 process_one_work+0x1ad/0x3c0 worker_thread+0x4c/0x390 ? rescuer_thread+0x320/0x320 kthread+0x149/0x190 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x1f/0x30 </TASK> smc_listen_work() abnormal case like port error --------------------------------------------------------------- | __smc_lgr_terminate() | |- smc_conn_kill() | |- smc_lgr_unregister_conn() | |- set conn->lgr = NULL smc_clc_wait_msg() | |- access conn->lgr (panic) | 2) Race between smc_setsockopt() and __smc_lgr_terminate() BUG: kernel NULL pointer dereference, address: 00000000000002e8 RIP: 0010:smc_setsockopt+0x17a/0x280 [smc] Call Trace: <TASK> __sys_setsockopt+0xfc/0x190 __x64_sys_setsockopt+0x20/0x30 do_syscall_64+0x34/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae </TASK> smc_setsockopt() abnormal case like port error -------------------------------------------------------------- | __smc_lgr_terminate() | |- smc_conn_kill() | |- smc_lgr_unregister_conn() | |- set conn->lgr = NULL mod_delayed_work() | |- access conn->lgr (panic) | There are some other panic places and they are caused by the similar reason as described above, which is accessing link group after termination, thus getting a NULL pointer or invalid resource. Currently, there seems to be no synchronization between the link group access and a sudden termination of it. This patch tries to fix this by introducing reference count of link group and not freeing link group until reference count is zero. Link group might be referred to by links or smc connections. So the operation to the link group reference count can be concluded as follows: object [hold or initialized as 1] [put] ------------------------------------------------------------------- link group smc_lgr_create() smc_lgr_free() connections smc_conn_create() smc_conn_free() links smcr_link_init() smcr_link_clear() Througth this way, we extend the life cycle of link group and ensure it is longer than the life cycle of connections and links above it, so that avoid invalid access to link group after its termination. Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: fix possible NULL deref in smc_pnet_add_eth()Eric Dumazet2022-01-121-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I missed that @ndev value can be NULL. I prefer not factorizing this NULL check, and instead clearly document where a NULL might be expected. general protection fault, probably for non-canonical address 0xdffffc00000000ba: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000005d0-0x00000000000005d7] CPU: 0 PID: 19875 Comm: syz-executor.2 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0xd7a/0x5470 kernel/locking/lockdep.c:4897 Code: 14 0e 41 bf 01 00 00 00 0f 86 c8 00 00 00 89 05 5c 20 14 0e e9 bd 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 9f 2e 00 00 49 81 3e 20 c5 1a 8f 0f 84 52 f3 ff RSP: 0018:ffffc900057071d0 EFLAGS: 00010002 RAX: dffffc0000000000 RBX: 1ffff92000ae0e65 RCX: 1ffff92000ae0e4c RDX: 00000000000000ba RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: fffffbfff1b24ae2 R11: 000000000008808a R12: 0000000000000000 R13: ffff888040ca4000 R14: 00000000000005d0 R15: 0000000000000000 FS: 00007fbd683e0700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2be22000 CR3: 0000000013fea000 CR4: 00000000003526f0 Call Trace: <TASK> lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 ref_tracker_alloc+0x182/0x440 lib/ref_tracker.c:84 netdev_tracker_alloc include/linux/netdevice.h:3859 [inline] smc_pnet_add_eth net/smc/smc_pnet.c:372 [inline] smc_pnet_enter net/smc/smc_pnet.c:492 [inline] smc_pnet_add+0x49a/0x14d0 net/smc/smc_pnet.c:555 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:731 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Fixes: b60645248af3 ("net/smc: add net device tracker to struct smc_pnetentry") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-01-103-9/+13
|\ | | | | | | | | | | | | Merge in fixes directly in prep for the 5.17 merge window. No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net/smc: Reset conn->lgr when link group registration failsWen Gu2022-01-063-9/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SMC connections might fail to be registered in a link group due to unable to find a usable link during its creation. As a result, smc_conn_create() will return a failure and most resources related to the connection won't be applied or initialized, such as conn->abort_work or conn->lnk. If smc_conn_free() is invoked later, it will try to access the uninitialized resources related to the connection, thus causing a warning or crash. This patch tries to fix this by resetting conn->lgr to NULL if an abnormal exit occurs in smc_lgr_register_conn(), thus avoiding the access to uninitialized resources in smc_conn_free(). Meanwhile, the new created link group should be terminated if smc connections can't be registered in it. So smc_lgr_cleanup_early() is modified to take care of link group only and invoked to terminate unusable link group by smc_conn_create(). The call to smc_conn_free() is moved out from smc_lgr_cleanup_early() to smc_conn_abort(). Fixes: 56bc3b2094b4 ("net/smc: assign link to a new connection") Suggested-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: add comments for smc_link_{usable|sendable}Dust Li2022-01-021-1/+16
| | | | | | | | | | | | | | | | | | | | Add comments for both smc_link_sendable() and smc_link_usable() to help better distinguish and use them. No function changes. Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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