summary refs log tree commit diff
path: root/net/ipv4/sysctl_net_ipv4.c
AgeCommit message (Collapse)Author
2018-06-04net-tcp: extend tcp_tw_reuse sysctl to enable loopback only optimizationMaciej Żenczykowski
This changes the /proc/sys/net/ipv4/tcp_tw_reuse from a boolean to an integer. It now takes the values 0, 1 and 2, where 0 and 1 behave as before, while 2 enables timewait socket reuse only for sockets that we can prove are loopback connections: ie. bound to 'lo' interface or where one of source or destination IPs is 127.0.0.0/8, ::ffff:127.0.0.0/104 or ::1. This enables quicker reuse of ephemeral ports for loopback connections - where tcp_tw_reuse is 100% safe from a protocol perspective (this assumes no artificially induced packet loss on 'lo'). This also makes estblishing many loopback connections *much* faster (allocating ports out of the first half of the ephemeral port range is significantly faster, then allocating from the second half) Without this change in a 32K ephemeral port space my sample program (it just establishes and closes [::1]:ephemeral -> [::1]:server_port connections in a tight loop) fails after 32765 connections in 24 seconds. With it enabled 50000 connections only take 4.7 seconds. This is particularly problematic for IPv6 where we only have one local address and cannot play tricks with varying source IP from 127.0.0.0/8 pool. Signed-off-by: Maciej Żenczykowski <maze@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Wei Wang <weiwan@google.com> Change-Id: I0377961749979d0301b7b62871a32a4b34b654e1 Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-18tcp: add tcp_comp_sack_nr sysctlEric Dumazet
This per netns sysctl allows for TCP SACK compression fine-tuning. This limits number of SACK that can be compressed. Using 0 disables SACK compression. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-18tcp: add tcp_comp_sack_delay_ns sysctlEric Dumazet
This per netns sysctl allows for TCP SACK compression fine-tuning. Its default value is 1,000,000, or 1 ms to meet TSO autosizing period. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27net: Drop pernet_operations::asyncKirill Tkhai
Synchronous pernet_operations are not allowed anymore. All are asynchronous. So, drop the structure member. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-16udp: Move the udp sysctl to namespace.Tonghao Zhang
This patch moves the udp_rmem_min, udp_wmem_min to namespace and init the udp_l3mdev_accept explicitly. The udp_rmem_min/udp_wmem_min affect udp rx/tx queue, with this patch namespaces can set them differently. Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-04net: Rename NETEVENT_MULTIPATH_HASH_UPDATEDavid Ahern
Rename NETEVENT_MULTIPATH_HASH_UPDATE to NETEVENT_IPV4_MPATH_HASH_UPDATE to denote it relates to a change in the IPv4 hash policy. Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-13net: Convert ipv4_sysctl_opsKirill Tkhai
These pernet_operations create and destroy sysctl, which are not touched by anybody else. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-15tcp: Namespace-ify sysctl_tcp_default_congestion_controlStephen Hemminger
Make default TCP default congestion control to a per namespace value. This changes default congestion control to a pointer to congestion ops (rather than implicit as first element of available lsit). The congestion control setting of new namespaces is inherited from the current setting of the root namespace. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-10tcp: Namespace-ify sysctl_tcp_rmem and sysctl_tcp_wmemEric Dumazet
Note that when a new netns is created, it inherits its sysctl_tcp_rmem and sysctl_tcp_wmem from initial netns. This change is needed so that we can refine TCP rcvbuf autotuning, to take RTT into consideration. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Wei Wang <weiwan@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Files removed in 'net-next' had their license header updated in 'net'. We take the remove from 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-03ipv4: Send a netevent whenever multipath hash policy is changedIdo Schimmel
Devices performing IPv4 forwarding need to update their multipath hash policy whenever it is changed. Inform these devices by generating a netevent. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: Petr Machata <petrm@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-28tcp: Namespace-ify sysctl_tcp_pacing_ca_ratioEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-28tcp: Namespace-ify sysctl_tcp_pacing_ss_ratioEric Dumazet
Also remove an obsolete comment about TCP pacing. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-28tcp: Namespace-ify sysctl_tcp_invalid_ratelimitEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-28tcp: Namespace-ify sysctl_tcp_autocorkingEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-28tcp: Namespace-ify sysctl_tcp_min_rtt_wlenEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-28tcp: Namespace-ify sysctl_tcp_min_tso_segsEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-28tcp: Namespace-ify sysctl_tcp_challenge_ack_limitEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-28tcp: Namespace-ify sysctl_tcp_limit_output_bytesEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-28tcp: Namespace-ify sysctl_tcp_workaround_signed_windowsEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-28tcp: Namespace-ify sysctl_tcp_tso_win_divisorEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-28tcp: Namespace-ify sysctl_tcp_moderate_rcvbufEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-28tcp: Namespace-ify sysctl_tcp_nometrics_saveEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_frtoEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_adv_win_scaleEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_app_winEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_dsackEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_max_reorderingEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_fackEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_abort_on_overflowEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_rfc1337Eric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_stdurgEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_retrans_collapseEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_slow_start_after_idleEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_thin_linear_timeoutsEric Dumazet
Note that sysctl_tcp_thin_dupack was not used, I deleted it. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_recoveryEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-27tcp: Namespace-ify sysctl_tcp_early_retransEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20tcp: socket option to set TCP fast open keyYuchung Cheng
New socket option TCP_FASTOPEN_KEY to allow different keys per listener. The listener by default uses the global key until the socket option is set. The key is a 16 bytes long binary data. This option has no effect on regular non-listener TCP sockets. Signed-off-by: Yuchung Cheng <ycheng@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Christoph Paasch <cpaasch@apple.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-01ipv4: Namespaceify tcp_fastopen_blackhole_timeout knobHaishuang Yan
Different namespace application might require different time period in second to disable Fastopen on active TCP sockets. Tested: Simulate following similar situation that the server's data gets dropped after 3WHS. C ---- syn-data ---> S C <--- syn/ack ----- S C ---- ack --------> S S (accept & write) C? X <- data ------ S [retry and timeout] And then print netstat of TCPFastOpenBlackhole, the counter increased as expected when the firewall blackhole issue is detected and active TFO is disabled. # cat /proc/net/netstat | awk '{print $91}' TCPFastOpenBlackhole 1 Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-01ipv4: Namespaceify tcp_fastopen_key knobHaishuang Yan
Different namespace application might require different tcp_fastopen_key independently of the host. David Miller pointed out there is a leak without releasing the context of tcp_fastopen_key during netns teardown. So add the release action in exit_batch path. Tested: 1. Container namespace: # cat /proc/sys/net/ipv4/tcp_fastopen_key: 2817fff2-f803cf97-eadfd1f3-78c0992b cookie key in tcp syn packets: Fast Open Cookie Kind: TCP Fast Open Cookie (34) Length: 10 Fast Open Cookie: 1e5dd82a8c492ca9 2. Host: # cat /proc/sys/net/ipv4/tcp_fastopen_key: 107d7c5f-68eb2ac7-02fb06e6-ed341702 cookie key in tcp syn packets: Fast Open Cookie Kind: TCP Fast Open Cookie (34) Length: 10 Fast Open Cookie: e213c02bf0afbc8a Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-01ipv4: Remove the 'publish' logic in tcp_fastopen_init_key_onceHaishuang Yan
The 'publish' logic is not necessary after commit dfea2aa65424 ("tcp: Do not call tcp_fastopen_reset_cipher from interrupt context"), because in tcp_fastopen_cookie_gen,it wouldn't call tcp_fastopen_init_key_once. Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-01ipv4: Namespaceify tcp_fastopen knobHaishuang Yan
Different namespace application might require enable TCP Fast Open feature independently of the host. This patch series continues making more of the TCP Fast Open related sysctl knobs be per net-namespace. Reported-by: Luca BRUNO <lucab@debian.org> Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-31tcp: remove low_latency sysctlFlorian Westphal
Was only checked by the removed prequeue code. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-15tcp: ULP infrastructureDave Watson
Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08tcp: Namespaceify sysctl_tcp_timestampsEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08tcp: Namespaceify sysctl_tcp_window_scalingEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08tcp: Namespaceify sysctl_tcp_sackEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-24net/tcp_fastopen: Disable active side TFO in certain scenariosWei Wang
Middlebox firewall issues can potentially cause server's data being blackholed after a successful 3WHS using TFO. Following are the related reports from Apple: https://www.nanog.org/sites/default/files/Paasch_Network_Support.pdf Slide 31 identifies an issue where the client ACK to the server's data sent during a TFO'd handshake is dropped. C ---> syn-data ---> S C <--- syn/ack ----- S C (accept & write) C <---- data ------- S C ----- ACK -> X S [retry and timeout] https://www.ietf.org/proceedings/94/slides/slides-94-tcpm-13.pdf Slide 5 shows a similar situation that the server's data gets dropped after 3WHS. C ---- syn-data ---> S C <--- syn/ack ----- S C ---- ack --------> S S (accept & write) C? X <- data ------ S [retry and timeout] This is the worst failure b/c the client can not detect such behavior to mitigate the situation (such as disabling TFO). Failing to proceed, the application (e.g., SSL library) may simply timeout and retry with TFO again, and the process repeats indefinitely. The proposed solution is to disable active TFO globally under the following circumstances: 1. client side TFO socket detects out of order FIN 2. client side TFO socket receives out of order RST We disable active side TFO globally for 1hr at first. Then if it happens again, we disable it for 2h, then 4h, 8h, ... And we reset the timeout to 1hr if a client side TFO sockets not opened on loopback has successfully received data segs from server. And we examine this condition during close(). The rational behind it is that when such firewall issue happens, application running on the client should eventually close the socket as it is not able to get the data it is expecting. Or application running on the server should close the socket as it is not able to receive any response from client. In both cases, out of order FIN or RST will get received on the client given that the firewall will not block them as no data are in those frames. And we want to disable active TFO globally as it helps if the middle box is very close to the client and most of the connections are likely to fail. Also, add a debug sysctl: tcp_fastopen_blackhole_detect_timeout_sec: the initial timeout to use when firewall blackhole issue happens. This can be set and read. When setting it to 0, it means to disable the active disable logic. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-24net: add rcu locking when changing early demuxDavid Ahern
systemd-sysctl is triggering a suspicious RCU usage message when net.ipv4.tcp_early_demux or net.ipv4.udp_early_demux is changed via a sysctl config file: [ 33.896184] =============================== [ 33.899558] [ ERR: suspicious RCU usage. ] [ 33.900624] 4.11.0-rc7+ #104 Not tainted [ 33.901698] ------------------------------- [ 33.903059] /home/dsa/kernel-2.git/net/ipv4/sysctl_net_ipv4.c:305 suspicious rcu_dereference_check() usage! [ 33.905724] other info that might help us debug this: [ 33.907656] rcu_scheduler_active = 2, debug_locks = 0 [ 33.909288] 1 lock held by systemd-sysctl/143: [ 33.910373] #0: (sb_writers#5){.+.+.+}, at: [<ffffffff8123a370>] file_start_write+0x45/0x48 [ 33.912407] stack backtrace: [ 33.914018] CPU: 0 PID: 143 Comm: systemd-sysctl Not tainted 4.11.0-rc7+ #104 [ 33.915631] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 33.917870] Call Trace: [ 33.918431] dump_stack+0x81/0xb6 [ 33.919241] lockdep_rcu_suspicious+0x10f/0x118 [ 33.920263] proc_configure_early_demux+0x65/0x10a [ 33.921391] proc_udp_early_demux+0x3a/0x41 add rcu locking to proc_configure_early_demux. Fixes: dddb64bcb3461 ("net: Add sysctl to toggle early demux for tcp and udp") Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>