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* net: drop the weight argument from netif_napi_addJakub Kicinski2022-09-281-2/+1
| | | | | | | | | | | We tell driver developers to always pass NAPI_POLL_WEIGHT as the weight to netif_napi_add(). This may be confusing to newcomers, drop the weight argument, those who really need to tweak the weight can use netif_napi_add_weight(). Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for CAN Link: https://lore.kernel.org/r/20220927132753.750069-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net: Fix data-races around netdev_max_backlog.Kuniyuki Iwashima2022-08-241-1/+1
| | | | | | | | | | | While reading netdev_max_backlog, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. While at it, we remove the unnecessary spaces in the doc. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: add per-cpu storage and net->core_statsEric Dumazet2022-03-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Before adding yet another possibly contended atomic_long_t, it is time to add per-cpu storage for existing ones: dev->tx_dropped, dev->rx_dropped, and dev->rx_nohandler Because many devices do not have to increment such counters, allocate the per-cpu storage on demand, so that dev_get_stats() does not have to spend considerable time folding zero counters. Note that some drivers have abused these counters which were supposed to be only used by core networking stack. v4: should use per_cpu_ptr() in dev_get_stats() (Jakub) v3: added a READ_ONCE() in netdev_core_stats_alloc() (Paolo) v2: add a missing include (reported by kernel test robot <lkp@intel.com>) Change in netdev_core_stats_alloc() (Jakub) Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: jeffreyji <jeffreyji@google.com> Reviewed-by: Brian Vazquez <brianvv@google.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20220311051420.2608812-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* gro_cells: avoid using synchronize_rcu() in gro_cells_destroy()Eric Dumazet2022-02-221-5/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Another thing making netns dismantles potentially very slow is located in gro_cells_destroy(), whenever cleanup_net() has to remove a device using gro_cells framework. RTNL is not held at this stage, so synchronize_net() is calling synchronize_rcu(): netdev_run_todo() ip_tunnel_dev_free() gro_cells_destroy() synchronize_net() synchronize_rcu() // Ouch. This patch uses call_rcu(), and gave me a 25x performance improvement in my tests. cleanup_net() is no longer blocked ~10 ms per synchronize_rcu() call. In the case we could not allocate the memory needed to queue the deferred free, use synchronize_rcu_expedited() v2: made percpu_free_defer_callback() static Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20220220041155.607637-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* gro_cells: reduce number of synchronize_net() callsEric Dumazet2020-11-251-1/+6
| | | | | | | | | | | | | | | | | | | After cited commit, gro_cells_destroy() became damn slow on hosts with a lot of cores. This is because we have one additional synchronize_net() per cpu as stated in the changelog. gro_cells_init() is setting NAPI_STATE_NO_BUSY_POLL, and this was enough to not have one synchronize_net() call per netif_napi_del() We can factorize all the synchronize_net() to a single one, right before freeing per-cpu memory. Fixes: 5198d545dba8 ("net: remove napi_hash_del() from driver-facing API") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20201124203822.1360107-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* gro_cells: make sure device is up in gro_cells_receive()Eric Dumazet2019-03-101-4/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We keep receiving syzbot reports [1] that show that tunnels do not play the rcu/IFF_UP rules properly. At device dismantle phase, gro_cells_destroy() will be called only after a full rcu grace period is observed after IFF_UP has been cleared. This means that IFF_UP needs to be tested before queueing packets into netif_rx() or gro_cells. This patch implements the test in gro_cells_receive() because too many callers do not seem to bother enough. [1] BUG: unable to handle kernel paging request at fffff4ca0b9ffffe PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.0.0+ #97 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:__skb_unlink include/linux/skbuff.h:1929 [inline] RIP: 0010:__skb_dequeue include/linux/skbuff.h:1945 [inline] RIP: 0010:__skb_queue_purge include/linux/skbuff.h:2656 [inline] RIP: 0010:gro_cells_destroy net/core/gro_cells.c:89 [inline] RIP: 0010:gro_cells_destroy+0x19d/0x360 net/core/gro_cells.c:78 Code: 03 42 80 3c 20 00 0f 85 53 01 00 00 48 8d 7a 08 49 8b 47 08 49 c7 07 00 00 00 00 48 89 f9 49 c7 47 08 00 00 00 00 48 c1 e9 03 <42> 80 3c 21 00 0f 85 10 01 00 00 48 89 c1 48 89 42 08 48 c1 e9 03 RSP: 0018:ffff8880aa3f79a8 EFLAGS: 00010a02 RAX: 00ffffffffffffe8 RBX: ffffe8ffffc64b70 RCX: 1ffff8ca0b9ffffe RDX: ffffc6505cffffe8 RSI: ffffffff858410ca RDI: ffffc6505cfffff0 RBP: ffff8880aa3f7a08 R08: ffff8880aa3e8580 R09: fffffbfff1263645 R10: fffffbfff1263644 R11: ffffffff8931b223 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffe8ffffc64b80 R15: ffffe8ffffc64b75 kobject: 'loop2' (000000004bd7d84a): kobject_uevent_env FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffff4ca0b9ffffe CR3: 0000000094941000 CR4: 00000000001406f0 Call Trace: kobject: 'loop2' (000000004bd7d84a): fill_kobj_path: path = '/devices/virtual/block/loop2' ip_tunnel_dev_free+0x19/0x60 net/ipv4/ip_tunnel.c:1010 netdev_run_todo+0x51c/0x7d0 net/core/dev.c:8970 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:116 ip_tunnel_delete_nets+0x423/0x5f0 net/ipv4/ip_tunnel.c:1124 vti_exit_batch_net+0x23/0x30 net/ipv4/ip_vti.c:495 ops_exit_list.isra.0+0x105/0x160 net/core/net_namespace.c:156 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:551 process_one_work+0x98e/0x1790 kernel/workqueue.c:2173 worker_thread+0x98/0xe40 kernel/workqueue.c:2319 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Modules linked in: CR2: fffff4ca0b9ffffe [ end trace 513fc9c1338d1cb3 ] RIP: 0010:__skb_unlink include/linux/skbuff.h:1929 [inline] RIP: 0010:__skb_dequeue include/linux/skbuff.h:1945 [inline] RIP: 0010:__skb_queue_purge include/linux/skbuff.h:2656 [inline] RIP: 0010:gro_cells_destroy net/core/gro_cells.c:89 [inline] RIP: 0010:gro_cells_destroy+0x19d/0x360 net/core/gro_cells.c:78 Code: 03 42 80 3c 20 00 0f 85 53 01 00 00 48 8d 7a 08 49 8b 47 08 49 c7 07 00 00 00 00 48 89 f9 49 c7 47 08 00 00 00 00 48 c1 e9 03 <42> 80 3c 21 00 0f 85 10 01 00 00 48 89 c1 48 89 42 08 48 c1 e9 03 RSP: 0018:ffff8880aa3f79a8 EFLAGS: 00010a02 RAX: 00ffffffffffffe8 RBX: ffffe8ffffc64b70 RCX: 1ffff8ca0b9ffffe RDX: ffffc6505cffffe8 RSI: ffffffff858410ca RDI: ffffc6505cfffff0 RBP: ffff8880aa3f7a08 R08: ffff8880aa3e8580 R09: fffffbfff1263645 R10: fffffbfff1263644 R11: ffffffff8931b223 R12: dffffc0000000000 kobject: 'loop3' (00000000e4ee57a6): kobject_uevent_env R13: 0000000000000000 R14: ffffe8ffffc64b80 R15: ffffe8ffffc64b75 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffff4ca0b9ffffe CR3: 0000000094941000 CR4: 00000000001406f0 Fixes: c9e6bc644e55 ("net: add gro_cells infrastructure") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* gro_cell: add napi_disable in gro_cells_destroyLorenzo Bianconi2018-12-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add napi_disable routine in gro_cells_destroy since starting from commit c42858eaf492 ("gro_cells: remove spinlock protecting receive queues") gro_cell_poll and gro_cells_destroy can run concurrently on napi_skbs list producing a kernel Oops if the tunnel interface is removed while gro_cell_poll is running. The following Oops has been triggered removing a vxlan device while the interface is receiving traffic [ 5628.948853] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 [ 5628.949981] PGD 0 P4D 0 [ 5628.950308] Oops: 0002 [#1] SMP PTI [ 5628.950748] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 4.20.0-rc6+ #41 [ 5628.952940] RIP: 0010:gro_cell_poll+0x49/0x80 [ 5628.955615] RSP: 0018:ffffc9000004fdd8 EFLAGS: 00010202 [ 5628.956250] RAX: 0000000000000000 RBX: ffffe8ffffc08150 RCX: 0000000000000000 [ 5628.957102] RDX: 0000000000000000 RSI: ffff88802356bf00 RDI: ffffe8ffffc08150 [ 5628.957940] RBP: 0000000000000026 R08: 0000000000000000 R09: 0000000000000000 [ 5628.958803] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000040 [ 5628.959661] R13: ffffe8ffffc08100 R14: 0000000000000000 R15: 0000000000000040 [ 5628.960682] FS: 0000000000000000(0000) GS:ffff88803ea00000(0000) knlGS:0000000000000000 [ 5628.961616] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5628.962359] CR2: 0000000000000008 CR3: 000000000221c000 CR4: 00000000000006b0 [ 5628.963188] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 5628.964034] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 5628.964871] Call Trace: [ 5628.965179] net_rx_action+0xf0/0x380 [ 5628.965637] __do_softirq+0xc7/0x431 [ 5628.966510] run_ksoftirqd+0x24/0x30 [ 5628.966957] smpboot_thread_fn+0xc5/0x160 [ 5628.967436] kthread+0x113/0x130 [ 5628.968283] ret_from_fork+0x3a/0x50 [ 5628.968721] Modules linked in: [ 5628.969099] CR2: 0000000000000008 [ 5628.969510] ---[ end trace 9d9dedc7181661fe ]--- [ 5628.970073] RIP: 0010:gro_cell_poll+0x49/0x80 [ 5628.972965] RSP: 0018:ffffc9000004fdd8 EFLAGS: 00010202 [ 5628.973611] RAX: 0000000000000000 RBX: ffffe8ffffc08150 RCX: 0000000000000000 [ 5628.974504] RDX: 0000000000000000 RSI: ffff88802356bf00 RDI: ffffe8ffffc08150 [ 5628.975462] RBP: 0000000000000026 R08: 0000000000000000 R09: 0000000000000000 [ 5628.976413] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000040 [ 5628.977375] R13: ffffe8ffffc08100 R14: 0000000000000000 R15: 0000000000000040 [ 5628.978296] FS: 0000000000000000(0000) GS:ffff88803ea00000(0000) knlGS:0000000000000000 [ 5628.979327] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5628.980044] CR2: 0000000000000008 CR3: 000000000221c000 CR4: 00000000000006b0 [ 5628.980929] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 5628.981736] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 5628.982409] Kernel panic - not syncing: Fatal exception in interrupt [ 5628.983307] Kernel Offset: disabled Fixes: c42858eaf492 ("gro_cells: remove spinlock protecting receive queues") Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* net: Generic XDPDavid S. Miller2017-04-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This provides a generic SKB based non-optimized XDP path which is used if either the driver lacks a specific XDP implementation, or the user requests it via a new IFLA_XDP_FLAGS value named XDP_FLAGS_SKB_MODE. It is arguable that perhaps I should have required something like this as part of the initial XDP feature merge. I believe this is critical for two reasons: 1) Accessibility. More people can play with XDP with less dependencies. Yes I know we have XDP support in virtio_net, but that just creates another depedency for learning how to use this facility. I wrote this to make life easier for the XDP newbies. 2) As a model for what the expected semantics are. If there is a pure generic core implementation, it serves as a semantic example for driver folks adding XDP support. One thing I have not tried to address here is the issue of XDP_PACKET_HEADROOM, thanks to Daniel for spotting that. It seems incredibly expensive to do a skb_cow(skb, XDP_PACKET_HEADROOM) or whatever even if the XDP program doesn't try to push headers at all. I think we really need the verifier to somehow propagate whether certain XDP helpers are used or not. v5: - Handle both negative and positive offset after running prog - Fix mac length in XDP_TX case (Alexei) - Use rcu_dereference_protected() in free_netdev (kbuild test robot) v4: - Fix MAC header adjustmnet before calling prog (David Ahern) - Disable LRO when generic XDP is installed (Michael Chan) - Bypass qdisc et al. on XDP_TX and record the event (Alexei) - Do not perform generic XDP on reinjected packets (DaveM) v3: - Make sure XDP program sees packet at MAC header, push back MAC header if we do XDP_TX. (Alexei) - Elide GRO when generic XDP is in use. (Alexei) - Add XDP_FLAG_SKB_MODE flag which the user can use to request generic XDP even if the driver has an XDP implementation. (Alexei) - Report whether SKB mode is in use in rtnl_xdp_fill() via XDP_FLAGS attribute. (Daniel) v2: - Add some "fall through" comments in switch statements based upon feedback from Andrew Lunn - Use RCU for generic xdp_prog, thanks to Johannes Berg. Tested-by: Andy Gospodarek <andy@greyhouse.net> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* gro_cells: move to net/core/gro_cells.cEric Dumazet2017-02-081-0/+92
We have many gro cells users, so lets move the code to avoid duplication. This creates a CONFIG_GRO_CELLS option. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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