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2022-09-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netPaolo Abeni1-1/+1
drivers/net/ethernet/freescale/fec.h 7d650df99d52 ("net: fec: add pm_qos support on imx6q platform") 40c79ce13b03 ("net: fec: add stop mode support for imx8 platform") Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-07Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextPaolo Abeni1-57/+59
Daniel Borkmann says: ==================== pull-request: bpf-next 2022-09-05 The following pull-request contains BPF updates for your *net-next* tree. We've added 106 non-merge commits during the last 18 day(s) which contain a total of 159 files changed, 5225 insertions(+), 1358 deletions(-). There are two small merge conflicts, resolve them as follows: 1) tools/testing/selftests/bpf/DENYLIST.s390x Commit 27e23836ce22 ("selftests/bpf: Add lru_bug to s390x deny list") in bpf tree was needed to get BPF CI green on s390x, but it conflicted with newly added tests on bpf-next. Resolve by adding both hunks, result: [...] lru_bug # prog 'printk': failed to auto-attach: -524 setget_sockopt # attach unexpected error: -524 (trampoline) cb_refs # expected error message unexpected error: -524 (trampoline) cgroup_hierarchical_stats # JIT does not support calling kernel function (kfunc) htab_update # failed to attach: ERROR: strerror_r(-524)=22 (trampoline) [...] 2) net/core/filter.c Commit 1227c1771dd2 ("net: Fix data-races around sysctl_[rw]mem_(max|default).") from net tree conflicts with commit 29003875bd5b ("bpf: Change bpf_setsockopt(SOL_SOCKET) to reuse sk_setsockopt()") from bpf-next tree. Take the code as it is from bpf-next tree, result: [...] if (getopt) { if (optname == SO_BINDTODEVICE) return -EINVAL; return sk_getsockopt(sk, SOL_SOCKET, optname, KERNEL_SOCKPTR(optval), KERNEL_SOCKPTR(optlen)); } return sk_setsockopt(sk, SOL_SOCKET, optname, KERNEL_SOCKPTR(optval), *optlen); [...] The main changes are: 1) Add any-context BPF specific memory allocator which is useful in particular for BPF tracing with bonus of performance equal to full prealloc, from Alexei Starovoitov. 2) Big batch to remove duplicated code from bpf_{get,set}sockopt() helpers as an effort to reuse the existing core socket code as much as possible, from Martin KaFai Lau. 3) Extend BPF flow dissector for BPF programs to just augment the in-kernel dissector with custom logic. In other words, allow for partial replacement, from Shmulik Ladkani. 4) Add a new cgroup iterator to BPF with different traversal options, from Hao Luo. 5) Support for BPF to collect hierarchical cgroup statistics efficiently through BPF integration with the rstat framework, from Yosry Ahmed. 6) Support bpf_{g,s}et_retval() under more BPF cgroup hooks, from Stanislav Fomichev. 7) BPF hash table and local storages fixes under fully preemptible kernel, from Hou Tao. 8) Add various improvements to BPF selftests and libbpf for compilation with gcc BPF backend, from James Hilliard. 9) Fix verifier helper permissions and reference state management for synchronous callbacks, from Kumar Kartikeya Dwivedi. 10) Add support for BPF selftest's xskxceiver to also be used against real devices that support MAC loopback, from Maciej Fijalkowski. 11) Various fixes to the bpf-helpers(7) man page generation script, from Quentin Monnet. 12) Document BPF verifier's tnum_in(tnum_range(), ...) gotchas, from Shung-Hsi Yu. 13) Various minor misc improvements all over the place. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (106 commits) bpf: Optimize rcu_barrier usage between hash map and bpf_mem_alloc. bpf: Remove usage of kmem_cache from bpf_mem_cache. bpf: Remove prealloc-only restriction for sleepable bpf programs. bpf: Prepare bpf_mem_alloc to be used by sleepable bpf programs. bpf: Remove tracing program restriction on map types bpf: Convert percpu hash map to per-cpu bpf_mem_alloc. bpf: Add percpu allocation support to bpf_mem_alloc. bpf: Batch call_rcu callbacks instead of SLAB_TYPESAFE_BY_RCU. bpf: Adjust low/high watermarks in bpf_mem_cache bpf: Optimize call_rcu in non-preallocated hash map. bpf: Optimize element count in non-preallocated hash map. bpf: Relax the requirement to use preallocated hash maps in tracing progs. samples/bpf: Reduce syscall overhead in map_perf_test. selftests/bpf: Improve test coverage of test_maps bpf: Convert hash map to bpf_mem_alloc. bpf: Introduce any context BPF specific memory allocator. selftest/bpf: Add test for bpf_getsockopt() bpf: Change bpf_getsockopt(SOL_IPV6) to reuse do_ipv6_getsockopt() bpf: Change bpf_getsockopt(SOL_IP) to reuse do_ip_getsockopt() bpf: Change bpf_getsockopt(SOL_TCP) to reuse do_tcp_getsockopt() ... ==================== Link: https://lore.kernel.org/r/20220905161136.9150-1-daniel@iogearbox.net Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-03bpf: Change bpf_getsockopt(SOL_TCP) to reuse do_tcp_getsockopt()Martin KaFai Lau1-2/+2
This patch changes bpf_getsockopt(SOL_TCP) to reuse do_tcp_getsockopt(). It removes the duplicated code from bpf_getsockopt(SOL_TCP). Before this patch, there were some optnames available to bpf_setsockopt(SOL_TCP) but missing in bpf_getsockopt(SOL_TCP). For example, TCP_NODELAY, TCP_MAXSEG, TCP_KEEPIDLE, TCP_KEEPINTVL, and a few more. It surprises users from time to time. This patch automatically closes this gap without duplicating more code. bpf_getsockopt(TCP_SAVED_SYN) does not free the saved_syn, so it stays in sol_tcp_sockopt(). For string name value like TCP_CONGESTION, bpf expects it is always null terminated, so sol_tcp_sockopt() decrements optlen by one before calling do_tcp_getsockopt() and the 'if (optlen < saved_optlen) memset(..,0,..);' in __bpf_getsockopt() will always do a null termination. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20220902002918.2894511-1-kafai@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-03bpf: net: Avoid do_tcp_getsockopt() taking sk lock when called from bpfMartin KaFai Lau1-9/+9
Similar to the earlier commit that changed sk_setsockopt() to use sockopt_{lock,release}_sock() such that it can avoid taking lock when called from bpf. This patch also changes do_tcp_getsockopt() to use sockopt_{lock,release}_sock() such that a latter patch can make bpf_getsockopt(SOL_TCP) to reuse do_tcp_getsockopt(). Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20220902002821.2889765-1-kafai@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-03bpf: net: Change do_tcp_getsockopt() to take the sockptr_t argumentMartin KaFai Lau1-35/+37
Similar to the earlier patch that changes sk_getsockopt() to take the sockptr_t argument . This patch also changes do_tcp_getsockopt() to take the sockptr_t argument such that a latter patch can make bpf_getsockopt(SOL_TCP) to reuse do_tcp_getsockopt(). Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20220902002815.2889332-1-kafai@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-02tcp: TX zerocopy should not sense pfmemalloc statusEric Dumazet1-1/+1
We got a recent syzbot report [1] showing a possible misuse of pfmemalloc page status in TCP zerocopy paths. Indeed, for pages coming from user space or other layers, using page_is_pfmemalloc() is moot, and possibly could give false positives. There has been attempts to make page_is_pfmemalloc() more robust, but not using it in the first place in this context is probably better, removing cpu cycles. Note to stable teams : You need to backport 84ce071e38a6 ("net: introduce __skb_fill_page_desc_noacc") as a prereq. Race is more probable after commit c07aea3ef4d4 ("mm: add a signature in struct page") because page_is_pfmemalloc() is now using low order bit from page->lru.next, which can change more often than page->index. Low order bit should never be set for lru.next (when used as an anchor in LRU list), so KCSAN report is mostly a false positive. Backporting to older kernel versions seems not necessary. [1] BUG: KCSAN: data-race in lru_add_fn / tcp_build_frag write to 0xffffea0004a1d2c8 of 8 bytes by task 18600 on cpu 0: __list_add include/linux/list.h:73 [inline] list_add include/linux/list.h:88 [inline] lruvec_add_folio include/linux/mm_inline.h:105 [inline] lru_add_fn+0x440/0x520 mm/swap.c:228 folio_batch_move_lru+0x1e1/0x2a0 mm/swap.c:246 folio_batch_add_and_move mm/swap.c:263 [inline] folio_add_lru+0xf1/0x140 mm/swap.c:490 filemap_add_folio+0xf8/0x150 mm/filemap.c:948 __filemap_get_folio+0x510/0x6d0 mm/filemap.c:1981 pagecache_get_page+0x26/0x190 mm/folio-compat.c:104 grab_cache_page_write_begin+0x2a/0x30 mm/folio-compat.c:116 ext4_da_write_begin+0x2dd/0x5f0 fs/ext4/inode.c:2988 generic_perform_write+0x1d4/0x3f0 mm/filemap.c:3738 ext4_buffered_write_iter+0x235/0x3e0 fs/ext4/file.c:270 ext4_file_write_iter+0x2e3/0x1210 call_write_iter include/linux/fs.h:2187 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x468/0x760 fs/read_write.c:578 ksys_write+0xe8/0x1a0 fs/read_write.c:631 __do_sys_write fs/read_write.c:643 [inline] __se_sys_write fs/read_write.c:640 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:640 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffffea0004a1d2c8 of 8 bytes by task 18611 on cpu 1: page_is_pfmemalloc include/linux/mm.h:1740 [inline] __skb_fill_page_desc include/linux/skbuff.h:2422 [inline] skb_fill_page_desc include/linux/skbuff.h:2443 [inline] tcp_build_frag+0x613/0xb20 net/ipv4/tcp.c:1018 do_tcp_sendpages+0x3e8/0xaf0 net/ipv4/tcp.c:1075 tcp_sendpage_locked net/ipv4/tcp.c:1140 [inline] tcp_sendpage+0x89/0xb0 net/ipv4/tcp.c:1150 inet_sendpage+0x7f/0xc0 net/ipv4/af_inet.c:833 kernel_sendpage+0x184/0x300 net/socket.c:3561 sock_sendpage+0x5a/0x70 net/socket.c:1054 pipe_to_sendpage+0x128/0x160 fs/splice.c:361 splice_from_pipe_feed fs/splice.c:415 [inline] __splice_from_pipe+0x222/0x4d0 fs/splice.c:559 splice_from_pipe fs/splice.c:594 [inline] generic_splice_sendpage+0x89/0xc0 fs/splice.c:743 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:931 splice_direct_to_actor+0x305/0x620 fs/splice.c:886 do_splice_direct+0xfb/0x180 fs/splice.c:974 do_sendfile+0x3bf/0x910 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64 fs/read_write.c:1303 [inline] __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1303 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x0000000000000000 -> 0xffffea0004a1d288 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 18611 Comm: syz-executor.4 Not tainted 6.0.0-rc2-syzkaller-00248-ge022620b5d05-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Fixes: c07aea3ef4d4 ("mm: add a signature in struct page") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Shakeel Butt <shakeelb@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-31bpf, net: Avoid loading module when calling bpf_setsockopt(TCP_CONGESTION)Martin KaFai Lau1-1/+1
When bpf prog changes tcp-cc by calling bpf_setsockopt(TCP_CONGESTION), it should not try to load module which may be a blocking operation. This details was correct in the v1 [0] but missed by mistake in the later revision in commit cb388e7ee3a8 ("bpf: net: Change do_tcp_setsockopt() to use the sockopt's lock_sock() and capable()"). This patch fixes it by checking the has_current_bpf_ctx(). [0] https://lore.kernel.org/bpf/20220727060921.2373314-1-kafai@fb.com/ Fixes: cb388e7ee3a8 ("bpf: net: Change do_tcp_setsockopt() to use the sockopt's lock_sock() and capable()") Signed-off-by: Martin KaFai Lau <martin.lau@linux.dev> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220830231946.791504-1-martin.lau@linux.dev
2022-08-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-2/+2
drivers/net/ethernet/mellanox/mlx5/core/en_fs.c 21234e3a84c7 ("net/mlx5e: Fix use after free in mlx5e_fs_init()") c7eafc5ed068 ("net/mlx5e: Convert ethtool_steering member of flow_steering struct to pointer") https://lore.kernel.org/all/20220825104410.67d4709c@canb.auug.org.au/ https://lore.kernel.org/all/20220823055533.334471-1-saeed@kernel.org/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-25net: Add a bhash2 table hashed by port and addressJoanne Koong1-1/+10
The current bind hashtable (bhash) is hashed by port only. In the socket bind path, we have to check for bind conflicts by traversing the specified port's inet_bind_bucket while holding the hashbucket's spinlock (see inet_csk_get_port() and inet_csk_bind_conflict()). In instances where there are tons of sockets hashed to the same port at different addresses, the bind conflict check is time-intensive and can cause softirq cpu lockups, as well as stops new tcp connections since __inet_inherit_port() also contests for the spinlock. This patch adds a second bind table, bhash2, that hashes by port and sk->sk_rcv_saddr (ipv4) and sk->sk_v6_rcv_saddr (ipv6). Searching the bhash2 table leads to significantly faster conflict resolution and less time holding the hashbucket spinlock. Please note a few things: * There can be the case where the a socket's address changes after it has been bound. There are two cases where this happens: 1) The case where there is a bind() call on INADDR_ANY (ipv4) or IPV6_ADDR_ANY (ipv6) and then a connect() call. The kernel will assign the socket an address when it handles the connect() 2) In inet_sk_reselect_saddr(), which is called when rebuilding the sk header and a few pre-conditions are met (eg rerouting fails). In these two cases, we need to update the bhash2 table by removing the entry for the old address, and add a new entry reflecting the updated address. * The bhash2 table must have its own lock, even though concurrent accesses on the same port are protected by the bhash lock. Bhash2 must have its own lock to protect against cases where sockets on different ports hash to different bhash hashbuckets but to the same bhash2 hashbucket. This brings up a few stipulations: 1) When acquiring both the bhash and the bhash2 lock, the bhash2 lock will always be acquired after the bhash lock and released before the bhash lock is released. 2) There are no nested bhash2 hashbucket locks. A bhash2 lock is always acquired+released before another bhash2 lock is acquired+released. * The bhash table cannot be superseded by the bhash2 table because for bind requests on INADDR_ANY (ipv4) or IPV6_ADDR_ANY (ipv6), every socket bound to that port must be checked for a potential conflict. The bhash table is the only source of port->socket associations. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-24net: Fix data-races around sysctl_max_skb_frags.Kuniyuki Iwashima1-2/+2
While reading sysctl_max_skb_frags, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 5f74f82ea34c ("net:Add sysctl_max_skb_frags") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-24tcp: annotate data-race around tcp_md5sig_pool_populatedEric Dumazet1-4/+10
tcp_md5sig_pool_populated can be read while another thread changes its value. The race has no consequence because allocations are protected with tcp_md5sig_mutex. This patch adds READ_ONCE() and WRITE_ONCE() to document the race and silence KCSAN. Reported-by: Abhishek Shah <abhishek.shah@columbia.edu> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-19bpf: Change bpf_setsockopt(SOL_TCP) to reuse do_tcp_setsockopt()Martin KaFai Lau1-2/+2
After the prep work in the previous patches, this patch removes all the dup code from bpf_setsockopt(SOL_TCP) and reuses the do_tcp_setsockopt(). The existing optname white-list is refactored into a new function sol_tcp_setsockopt(). The sol_tcp_setsockopt() also calls the bpf_sol_tcp_setsockopt() to handle the TCP_BPF_XXX specific optnames. bpf_setsockopt(TCP_SAVE_SYN) now also allows a value 2 to save the eth header also and it comes for free from do_tcp_setsockopt(). Reviewed-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/r/20220817061819.4180146-1-kafai@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-19bpf: net: Change do_tcp_setsockopt() to use the sockopt's lock_sock() and ↵Martin KaFai Lau1-9/+9
capable() Similar to the earlier patch that avoids sk_setsockopt() from taking sk lock and doing capable test when called by bpf. This patch changes do_tcp_setsockopt() to use the sockopt_{lock,release}_sock() and sockopt_[ns_]capable(). Reviewed-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/r/20220817061730.4176021-1-kafai@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18tcp: handle pure FIN case correctlyCong Wang1-1/+1
When skb->len==0, the recv_actor() returns 0 too, but we also use 0 for error conditions. This patch amends this by propagating the errors to tcp_read_skb() so that we can distinguish skb->len==0 case from error cases. Fixes: 04919bed948d ("tcp: Introduce tcp_read_skb()") Reported-by: Eric Dumazet <edumazet@google.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-18tcp: refactor tcp_read_skb() a bitCong Wang1-17/+9
As tcp_read_skb() only reads one skb at a time, the while loop is unnecessary, we can turn it into an if. This also simplifies the code logic. Cc: Eric Dumazet <edumazet@google.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-18tcp: fix tcp_cleanup_rbuf() for tcp_read_skb()Cong Wang1-10/+14
tcp_cleanup_rbuf() retrieves the skb from sk_receive_queue, it assumes the skb is not yet dequeued. This is no longer true for tcp_read_skb() case where we dequeue the skb first. Fix this by introducing a helper __tcp_cleanup_rbuf() which does not require any skb and calling it in tcp_read_skb(). Fixes: 04919bed948d ("tcp: Introduce tcp_read_skb()") Cc: Eric Dumazet <edumazet@google.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-18tcp: fix sock skb accounting in tcp_read_skb()Cong Wang1-0/+1
Before commit 965b57b469a5 ("net: Introduce a new proto_ops ->read_skb()"), skb was not dequeued from receive queue hence when we close TCP socket skb can be just flushed synchronously. After this commit, we have to uncharge skb immediately after being dequeued, otherwise it is still charged in the original sock. And we still need to retain skb->sk, as eBPF programs may extract sock information from skb->sk. Therefore, we have to call skb_set_owner_sk_safe() here. Fixes: 965b57b469a5 ("net: Introduce a new proto_ops ->read_skb()") Reported-and-tested-by: syzbot+a0e6f8738b58f7654417@syzkaller.appspotmail.com Tested-by: Stanislav Fomichev <sdf@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-7/+16
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-27tcp: md5: fix IPv4-mapped supportEric Dumazet1-3/+12
After the blamed commit, IPv4 SYN packets handled by a dual stack IPv6 socket are dropped, even if perfectly valid. $ nstat | grep MD5 TcpExtTCPMD5Failure 5 0.0 For a dual stack listener, an incoming IPv4 SYN packet would call tcp_inbound_md5_hash() with @family == AF_INET, while tp->af_specific is pointing to tcp_sock_ipv6_specific. Only later when an IPv4-mapped child is created, tp->af_specific is changed to tcp_sock_ipv6_mapped_specific. Fixes: 7bbb765b7349 ("net/tcp: Merge TCP-MD5 inbound callbacks") Reported-by: Brian Vazquez <brianvv@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Dmitry Safonov <dima@arista.com> Tested-by: Leonard Crestez <cdleonard@gmail.com> Link: https://lore.kernel.org/r/20220726115743.2759832-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-27tcp: allow tls to decrypt directly from the tcp rcv queueJakub Kicinski1-1/+41
Expose TCP rx queue accessor and cleanup, so that TLS can decrypt directly from the TCP queue. The expectation is that the caller can access the skb returned from tcp_recv_skb() and up to inq bytes worth of data (some of which may be in ->next skbs) and then call tcp_read_done() when data has been consumed. The socket lock must be held continuously across those two operations. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-25net: Fix data-races around sysctl_[rw]mem(_offset)?.Kuniyuki Iwashima1-3/+3
While reading these sysctl variables, they can be changed concurrently. Thus, we need to add READ_ONCE() to their readers. - .sysctl_rmem - .sysctl_rwmem - .sysctl_rmem_offset - .sysctl_wmem_offset - sysctl_tcp_rmem[1, 2] - sysctl_tcp_wmem[1, 2] - sysctl_decnet_rmem[1] - sysctl_decnet_wmem[1] - sysctl_tipc_rmem[1] Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-22tcp: Fix a data-race around sysctl_tcp_autocorking.Kuniyuki Iwashima1-1/+1
While reading sysctl_tcp_autocorking, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: f54b311142a9 ("tcp: auto corking") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-5/+8
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-20Merge branch 'io_uring-zerocopy-send' of ↵Jakub Kicinski1-11/+20
git://git.kernel.org/pub/scm/linux/kernel/git/kuba/linux Pavel Begunkov says: ==================== io_uring zerocopy send The patchset implements io_uring zerocopy send. It works with both registered and normal buffers, mixing is allowed but not recommended. Apart from usual request completions, just as with MSG_ZEROCOPY, io_uring separately notifies the userspace when buffers are freed and can be reused (see API design below), which is delivered into io_uring's Completion Queue. Those "buffer-free" notifications are not necessarily per request, but the userspace has control over it and should explicitly attaching a number of requests to a single notification. The series also adds some internal optimisations when used with registered buffers like removing page referencing. From the kernel networking perspective there are two main changes. The first one is passing ubuf_info into the network layer from io_uring (inside of an in kernel struct msghdr). This allows extra optimisations, e.g. ubuf_info caching on the io_uring side, but also helps to avoid cross-referencing and synchronisation problems. The second part is an optional optimisation removing page referencing for requests with registered buffers. Benchmarking UDP with an optimised version of the selftest (see [1]), which sends a bunch of requests, waits for completions and repeats. "+ flush" column posts one additional "buffer-free" notification per request, and just "zc" doesn't post buffer notifications at all. NIC (requests / second): IO size | non-zc | zc | zc + flush 4000 | 495134 | 606420 (+22%) | 558971 (+12%) 1500 | 551808 | 577116 (+4.5%) | 565803 (+2.5%) 1000 | 584677 | 592088 (+1.2%) | 560885 (-4%) 600 | 596292 | 598550 (+0.4%) | 555366 (-6.7%) dummy (requests / second): IO size | non-zc | zc | zc + flush 8000 | 1299916 | 2396600 (+84%) | 2224219 (+71%) 4000 | 1869230 | 2344146 (+25%) | 2170069 (+16%) 1200 | 2071617 | 2361960 (+14%) | 2203052 (+6%) 600 | 2106794 | 2381527 (+13%) | 2195295 (+4%) Previously it also brought a massive performance speedup compared to the msg_zerocopy tool (see [3]), which is probably not super interesting. There is also an additional bunch of refcounting optimisations that was omitted from the series for simplicity and as they don't change the picture drastically, they will be sent as follow up, as well as flushing optimisations closing the performance gap b/w two last columns. For TCP on localhost (with hacks enabling localhost zerocopy) and including additional overhead for receive: IO size | non-zc | zc 1200 | 4174 | 4148 4096 | 7597 | 11228 Using a real NIC 1200 bytes, zc is worse than non-zc ~5-10%, maybe the omitted optimisations will somewhat help, should look better for 4000, but couldn't test properly because of setup problems. Links: liburing (benchmark + tests): [1] https://github.com/isilence/liburing/tree/zc_v4 kernel repo: [2] https://github.com/isilence/linux/tree/zc_v4 RFC v1: [3] https://lore.kernel.org/io-uring/cover.1638282789.git.asml.silence@gmail.com/ RFC v2: https://lore.kernel.org/io-uring/cover.1640029579.git.asml.silence@gmail.com/ Net patches based: git@github.com:isilence/linux.git zc_v4-net-base or https://github.com/isilence/linux/tree/zc_v4-net-base API design overview: The series introduces an io_uring concept of notifactors. From the userspace perspective it's an entity to which it can bind one or more requests and then requesting to flush it. Flushing a notifier makes it impossible to attach new requests to it, and instructs the notifier to post a completion once all requests attached to it are completed and the kernel doesn't need the buffers anymore. Notifications are stored in notification slots, which should be registered as an array in io_uring. Each slot stores only one notifier at any particular moment. Flushing removes it from the slot and the slot automatically replaces it with a new notifier. All operations with notifiers are done by specifying an index of a slot it's currently in. When registering a notification the userspace specifies a u64 tag for each slot, which will be copied in notification completion entries as cqe::user_data. cqe::res is 0 and cqe::flags is equal to wrap around u32 sequence number counting notifiers of a slot. ==================== Link: https://lore.kernel.org/r/cover.1657643355.git.asml.silence@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-20tcp: support externally provided ubufsPavel Begunkov1-11/+22
Teach tcp how to use external ubuf_info provided in msghdr and also prepare it for managed frags by sprinkling skb_zcopy_downgrade_managed() when it could mix managed and not managed frags. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-18tcp: Fix data-races around sysctl_tcp_fastopen.Kuniyuki Iwashima1-2/+4
While reading sysctl_tcp_fastopen, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 2100c8d2d9db ("net-tcp: Fast Open base") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18tcp: Fix data-races around some timeout sysctl knobs.Kuniyuki Iwashima1-1/+1
While reading these sysctl knobs, they can be changed concurrently. Thus, we need to add READ_ONCE() to their readers. - tcp_retries1 - tcp_retries2 - tcp_orphan_retries - tcp_fin_timeout Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18tcp: Fix data-races around sysctl_tcp_reordering.Kuniyuki Iwashima1-1/+1
While reading sysctl_tcp_reordering, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18tcp: Fix data-races around sysctl_tcp_syn(ack)?_retries.Kuniyuki Iwashima1-1/+2
While reading sysctl_tcp_syn(ack)?_retries, they can be changed concurrently. Thus, we need to add READ_ONCE() to their readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-1/+2
include/net/sock.h 310731e2f161 ("net: Fix data-races around sysctl_mem.") e70f3c701276 ("Revert "net: set SK_MEM_QUANTUM to 4096"") https://lore.kernel.org/all/20220711120211.7c8b7cba@canb.auug.org.au/ net/ipv4/fib_semantics.c 747c14307214 ("ip: fix dflt addr selection for connected nexthop") d62607c3fe45 ("net: rename reference+tracking helpers") net/tls/tls.h include/net/tls.h 3d8c51b25a23 ("net/tls: Check for errors in tls_device_init") 587903142308 ("tls: create an internal header") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-09Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski1-0/+44
Daniel Borkmann says: ==================== pull-request: bpf-next 2022-07-09 We've added 94 non-merge commits during the last 19 day(s) which contain a total of 125 files changed, 5141 insertions(+), 6701 deletions(-). The main changes are: 1) Add new way for performing BTF type queries to BPF, from Daniel Müller. 2) Add inlining of calls to bpf_loop() helper when its function callback is statically known, from Eduard Zingerman. 3) Implement BPF TCP CC framework usability improvements, from Jörn-Thorben Hinz. 4) Add LSM flavor for attaching per-cgroup BPF programs to existing LSM hooks, from Stanislav Fomichev. 5) Remove all deprecated libbpf APIs in prep for 1.0 release, from Andrii Nakryiko. 6) Add benchmarks around local_storage to BPF selftests, from Dave Marchevsky. 7) AF_XDP sample removal (given move to libxdp) and various improvements around AF_XDP selftests, from Magnus Karlsson & Maciej Fijalkowski. 8) Add bpftool improvements for memcg probing and bash completion, from Quentin Monnet. 9) Add arm64 JIT support for BPF-2-BPF coupled with tail calls, from Jakub Sitnicki. 10) Sockmap optimizations around throughput of UDP transmissions which have been improved by 61%, from Cong Wang. 11) Rework perf's BPF prologue code to remove deprecated functions, from Jiri Olsa. 12) Fix sockmap teardown path to avoid sleepable sk_psock_stop, from John Fastabend. 13) Fix libbpf's cleanup around legacy kprobe/uprobe on error case, from Chuang Wang. 14) Fix libbpf's bpf_helpers.h to work with gcc for the case of its sec/pragma macro, from James Hilliard. 15) Fix libbpf's pt_regs macros for riscv to use a0 for RC register, from Yixun Lan. 16) Fix bpftool to show the name of type BPF_OBJ_LINK, from Yafang Shao. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (94 commits) selftests/bpf: Fix xdp_synproxy build failure if CONFIG_NF_CONNTRACK=m/n bpf: Correctly propagate errors up from bpf_core_composites_match libbpf: Disable SEC pragma macro on GCC bpf: Check attach_func_proto more carefully in check_return_code selftests/bpf: Add test involving restrict type qualifier bpftool: Add support for KIND_RESTRICT to gen min_core_btf command MAINTAINERS: Add entry for AF_XDP selftests files selftests, xsk: Rename AF_XDP testing app bpf, docs: Remove deprecated xsk libbpf APIs description selftests/bpf: Add benchmark for local_storage RCU Tasks Trace usage libbpf, riscv: Use a0 for RC register libbpf: Remove unnecessary usdt_rel_ip assignments selftests/bpf: Fix few more compiler warnings selftests/bpf: Fix bogus uninitialized variable warning bpftool: Remove zlib feature test from Makefile libbpf: Cleanup the legacy uprobe_event on failed add/attach_event() libbpf: Fix wrong variable used in perf_event_uprobe_open_legacy() libbpf: Cleanup the legacy kprobe_event on failed add/attach_event() selftests/bpf: Add type match test against kernel's task_struct selftests/bpf: Add nested type to type based tests ... ==================== Link: https://lore.kernel.org/r/20220708233145.32365-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-08tcp: Fix a data-race around sysctl_tcp_max_orphans.Kuniyuki Iwashima1-1/+2
While reading sysctl_tcp_max_orphans, it can be changed concurrently. So, we need to add READ_ONCE() to avoid a data-race. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-29tcp: diag: add support for TIME_WAIT sockets to tcp_abort()Eric Dumazet1-9/+17
Currently, "ss -K -ta ..." does not support TIME_WAIT sockets. Issue has been raised at least two times in the past [1] [2] it is time to fix it. [1] https://lore.kernel.org/netdev/ba65f579-4e69-ae0d-4770-bc6234beb428@gmail.com/ [2] https://lore.kernel.org/netdev/CANn89i+R9RgmD=AQ4vX1Vb_SQAj4c3fi7-ZtQz-inYY4Sq4CMQ@mail.gmail.com/T/ While we are at it, use inet_sk_state_load() while tcp_abort() does not hold a lock on the socket. Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Link: https://lore.kernel.org/r/20220627121038.226500-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-20net: Introduce a new proto_ops ->read_skb()Cong Wang1-6/+3
Currently both splice() and sockmap use ->read_sock() to read skb from receive queue, but for sockmap we only read one entire skb at a time, so ->read_sock() is too conservative to use. Introduce a new proto_ops ->read_skb() which supports this sematic, with this we can finally pass the ownership of skb to recv actors. For non-TCP protocols, all ->read_sock() can be simply converted to ->read_skb(). Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20220615162014.89193-3-xiyou.wangcong@gmail.com
2022-06-20tcp: Introduce tcp_read_skb()Cong Wang1-0/+47
This patch inroduces tcp_read_skb() based on tcp_read_sock(), a preparation for the next patch which actually introduces a new sock ops. TCP is special here, because it has tcp_read_sock() which is mainly used by splice(). tcp_read_sock() supports partial read and arbitrary offset, neither of them is needed for sockmap. Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20220615162014.89193-2-xiyou.wangcong@gmail.com
2022-06-17tcp: fix build...David S. Miller1-16/+0
Remove accidental dup of tcp_wmem_schedule. Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-17tcp: fix possible freeze in tx path under memory pressureEric Dumazet1-0/+17
Blamed commit only dealt with applications issuing small writes. Issue here is that we allow to force memory schedule for the sk_buff allocation, but we have no guarantee that sendmsg() is able to copy some payload in it. In this patch, I make sure the socket can use up to tcp_wmem[0] bytes. For example, if we consider tcp_wmem[0] = 4096 (default on x86), and initial skb->truesize being 1280, tcp_sendmsg() is able to copy up to 2816 bytes under memory pressure. Before this patch a sendmsg() sending more than 2816 bytes would either block forever (if persistent memory pressure), or return -EAGAIN. For bigger MTU networks, it is advised to increase tcp_wmem[0] to avoid sending too small packets. v2: deal with zero copy paths. Fixes: 8e4d980ac215 ("tcp: fix behavior for epoll edge trigger") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Reviewed-by: Wei Wang <weiwan@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-17tcp: fix possible freeze in tx path under memory pressureEric Dumazet1-4/+29
Blamed commit only dealt with applications issuing small writes. Issue here is that we allow to force memory schedule for the sk_buff allocation, but we have no guarantee that sendmsg() is able to copy some payload in it. In this patch, I make sure the socket can use up to tcp_wmem[0] bytes. For example, if we consider tcp_wmem[0] = 4096 (default on x86), and initial skb->truesize being 1280, tcp_sendmsg() is able to copy up to 2816 bytes under memory pressure. Before this patch a sendmsg() sending more than 2816 bytes would either block forever (if persistent memory pressure), or return -EAGAIN. For bigger MTU networks, it is advised to increase tcp_wmem[0] to avoid sending too small packets. v2: deal with zero copy paths. Fixes: 8e4d980ac215 ("tcp: fix behavior for epoll edge trigger") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Reviewed-by: Wei Wang <weiwan@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-12/+2
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-16Revert "net: Add a second bind table hashed by port and address"Joanne Koong1-12/+2
This reverts: commit d5a42de8bdbe ("net: Add a second bind table hashed by port and address") commit 538aaf9b2383 ("selftests: Add test for timing a bind request to a port with a populated bhash entry") Link: https://lore.kernel.org/netdev/20220520001834.2247810-1-kuba@kernel.org/ There are a few things that need to be fixed here: * Updating bhash2 in cases where the socket's rcv saddr changes * Adding bhash2 hashbucket locks Links to syzbot reports: https://lore.kernel.org/netdev/00000000000022208805e0df247a@google.com/ https://lore.kernel.org/netdev/0000000000003f33bc05dfaf44fe@google.com/ Fixes: d5a42de8bdbe ("net: Add a second bind table hashed by port and address") Reported-by: syzbot+015d756bbd1f8b5c8f09@syzkaller.appspotmail.com Reported-by: syzbot+98fd2d1422063b0f8c44@syzkaller.appspotmail.com Reported-by: syzbot+0a847a982613c6438fba@syzkaller.appspotmail.com Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/r/20220615193213.2419568-1-joannelkoong@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-11net: keep sk->sk_forward_alloc as small as possibleEric Dumazet1-7/+0
Currently, tcp_memory_allocated can hit tcp_mem[] limits quite fast. Each TCP socket can forward allocate up to 2 MB of memory, even after flow became less active. 10,000 sockets can have reserved 20 GB of memory, and we have no shrinker in place to reclaim that. Instead of trying to reclaim the extra allocations in some places, just keep sk->sk_forward_alloc values as small as possible. This should not impact performance too much now we have per-cpu reserves: Changes to tcp_memory_allocated should not be too frequent. For sockets not using SO_RESERVE_MEM: - idle sockets (no packets in tx/rx queues) have zero forward alloc. - non idle sockets have a forward alloc smaller than one page. Note: - Removal of SK_RECLAIM_CHUNK and SK_RECLAIM_THRESHOLD is left to MPTCP maintainers as a follow up. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-11net: add per_cpu_fw_alloc field to struct protoEric Dumazet1-0/+2
Each protocol having a ->memory_allocated pointer gets a corresponding per-cpu reserve, that following patches will use. Instead of having reserved bytes per socket, we want to have per-cpu reserves. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-11net: remove SK_MEM_QUANTUM and SK_MEM_QUANTUM_SHIFTEric Dumazet1-2/+2
Due to memcg interface, SK_MEM_QUANTUM is effectively PAGE_SIZE. This might change in the future, but it seems better to avoid the confusion. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-21net: Add a second bind table hashed by port and addressJoanne Koong1-2/+12
We currently have one tcp bind table (bhash) which hashes by port number only. In the socket bind path, we check for bind conflicts by traversing the specified port's inet_bind2_bucket while holding the bucket's spinlock (see inet_csk_get_port() and inet_csk_bind_conflict()). In instances where there are tons of sockets hashed to the same port at different addresses, checking for a bind conflict is time-intensive and can cause softirq cpu lockups, as well as stops new tcp connections since __inet_inherit_port() also contests for the spinlock. This patch proposes adding a second bind table, bhash2, that hashes by port and ip address. Searching the bhash2 table leads to significantly faster conflict resolution and less time holding the spinlock. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-13net: inet: Retire port only listening_hashMartin KaFai Lau1-1/+0
The listen sk is currently stored in two hash tables, listening_hash (hashed by port) and lhash2 (hashed by port and address). After commit 0ee58dad5b06 ("net: tcp6: prefer listeners bound to an address") and commit d9fbc7f6431f ("net: tcp: prefer listeners bound to an address"), the TCP-SYN lookup fast path does not use listening_hash. The commit 05c0b35709c5 ("tcp: seq_file: Replace listening_hash with lhash2") also moved the seq_file (/proc/net/tcp) iteration usage from listening_hash to lhash2. There are still a few listening_hash usages left. One of them is inet_reuseport_add_sock() which uses the listening_hash to search a listen sk during the listen() system call. This turns out to be very slow on use cases that listen on many different VIPs at a popular port (e.g. 443). [ On top of the slowness in adding to the tail in the IPv6 case ]. The latter patch has a selftest to demonstrate this case. This patch takes this chance to move all remaining listening_hash usages to lhash2 and then retire listening_hash. Since most changes need to be done together, it is hard to cut the listening_hash to lhash2 switch into small patches. The changes in this patch is highlighted here for the review purpose. 1. Because of the listening_hash removal, lhash2 can use the sk->sk_nulls_node instead of the icsk->icsk_listen_portaddr_node. This will also keep the sk_unhashed() check to work as is after stop adding sk to listening_hash. The union is removed from inet_listen_hashbucket because only nulls_head is needed. 2. icsk->icsk_listen_portaddr_node and its helpers are removed. 3. The current lhash2 users needs to iterate with sk_nulls_node instead of icsk_listen_portaddr_node. One case is in the inet[6]_lhash2_lookup(). Another case is the seq_file iterator in tcp_ipv4.c. One thing to note is sk_nulls_next() is needed because the old inet_lhash2_for_each_icsk_continue() does a "next" first before iterating. 4. Move the remaining listening_hash usage to lhash2 inet_reuseport_add_sock() which this series is trying to improve. inet_diag.c and mptcp_diag.c are the final two remaining use cases and is moved to lhash2 now also. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-30Merge branch 'tcp-pass-back-data-left-in-socket-after-receive' of ↵Jakub Kicinski1-6/+10
git://git.kernel.org/pub/scm/linux/kernel/git/kuba/linux Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-30tcp: pass back data left in socket after receiveJens Axboe1-6/+10
This is currently done for CMSG_INQ, add an ability to do so via struct msghdr as well and have CMSG_INQ use that too. If the caller sets msghdr->msg_get_inq, then we'll pass back the hint in msghdr->msg_inq. Rearrange struct msghdr a bit so we can add this member while shrinking it at the same time. On a 64-bit build, it was 96 bytes before this change and 88 bytes afterwards. Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/650c22ca-cffc-0255-9a05-2413a1e20826@kernel.dk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-27net: generalize skb freeing deferral to per-cpu listsEric Dumazet1-24/+1
Logic added in commit f35f821935d8 ("tcp: defer skb freeing after socket lock is released") helped bulk TCP flows to move the cost of skbs frees outside of critical section where socket lock was held. But for RPC traffic, or hosts with RFS enabled, the solution is far from being ideal. For RPC traffic, recvmsg() has to return to user space right after skb payload has been consumed, meaning that BH handler has no chance to pick the skb before recvmsg() thread. This issue is more visible with BIG TCP, as more RPC fit one skb. For RFS, even if BH handler picks the skbs, they are still picked from the cpu on which user thread is running. Ideally, it is better to free the skbs (and associated page frags) on the cpu that originally allocated them. This patch removes the per socket anchor (sk->defer_list) and instead uses a per-cpu list, which will hold more skbs per round. This new per-cpu list is drained at the end of net_action_rx(), after incoming packets have been processed, to lower latencies. In normal conditions, skbs are added to the per-cpu list with no further action. In the (unlikely) cases where the cpu does not run net_action_rx() handler fast enough, we use an IPI to raise NET_RX_SOFTIRQ on the remote cpu. Also, we do not bother draining the per-cpu list from dev_cpu_dead() This is because skbs in this list have no requirement on how fast they should be freed. Note that we can add in the future a small per-cpu cache if we see any contention on sd->defer_lock. Tested on a pair of hosts with 100Gbit NIC, RFS enabled, and /proc/sys/net/ipv4/tcp_rmem[2] tuned to 16MB to work around page recycling strategy used by NIC driver (its page pool capacity being too small compared to number of skbs/pages held in sockets receive queues) Note that this tuning was only done to demonstrate worse conditions for skb freeing for this particular test. These conditions can happen in more general production workload. 10 runs of one TCP_STREAM flow Before: Average throughput: 49685 Mbit. Kernel profiles on cpu running user thread recvmsg() show high cost for skb freeing related functions (*) 57.81% [kernel] [k] copy_user_enhanced_fast_string (*) 12.87% [kernel] [k] skb_release_data (*) 4.25% [kernel] [k] __free_one_page (*) 3.57% [kernel] [k] __list_del_entry_valid 1.85% [kernel] [k] __netif_receive_skb_core 1.60% [kernel] [k] __skb_datagram_iter (*) 1.59% [kernel] [k] free_unref_page_commit (*) 1.16% [kernel] [k] __slab_free 1.16% [kernel] [k] _copy_to_iter (*) 1.01% [kernel] [k] kfree (*) 0.88% [kernel] [k] free_unref_page 0.57% [kernel] [k] ip6_rcv_core 0.55% [kernel] [k] ip6t_do_table 0.54% [kernel] [k] flush_smp_call_function_queue (*) 0.54% [kernel] [k] free_pcppages_bulk 0.51% [kernel] [k] llist_reverse_order 0.38% [kernel] [k] process_backlog (*) 0.38% [kernel] [k] free_pcp_prepare 0.37% [kernel] [k] tcp_recvmsg_locked (*) 0.37% [kernel] [k] __list_add_valid 0.34% [kernel] [k] sock_rfree 0.34% [kernel] [k] _raw_spin_lock_irq (*) 0.33% [kernel] [k] __page_cache_release 0.33% [kernel] [k] tcp_v6_rcv (*) 0.33% [kernel] [k] __put_page (*) 0.29% [kernel] [k] __mod_zone_page_state 0.27% [kernel] [k] _raw_spin_lock After patch: Average throughput: 73076 Mbit. Kernel profiles on cpu running user thread recvmsg() looks better: 81.35% [kernel] [k] copy_user_enhanced_fast_string 1.95% [kernel] [k] _copy_to_iter 1.95% [kernel] [k] __skb_datagram_iter 1.27% [kernel] [k] __netif_receive_skb_core 1.03% [kernel] [k] ip6t_do_table 0.60% [kernel] [k] sock_rfree 0.50% [kernel] [k] tcp_v6_rcv 0.47% [kernel] [k] ip6_rcv_core 0.45% [kernel] [k] read_tsc 0.44% [kernel] [k] _raw_spin_lock_irqsave 0.37% [kernel] [k] _raw_spin_lock 0.37% [kernel] [k] native_irq_return_iret 0.33% [kernel] [k] __inet6_lookup_established 0.31% [kernel] [k] ip6_protocol_deliver_rcu 0.29% [kernel] [k] tcp_rcv_established 0.29% [kernel] [k] llist_reverse_order v2: kdoc issue (kernel bots) do not defer if (alloc_cpu == smp_processor_id()) (Paolo) replace the sk_buff_head with a single-linked list (Jakub) add a READ_ONCE()/WRITE_ONCE() for the lockless read of sd->defer_list Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20220422201237.416238-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-12net: remove noblock parameter from recvmsg() entitiesOliver Hartkopp1-11/+8
The internal recvmsg() functions have two parameters 'flags' and 'noblock' that were merged inside skb_recv_datagram(). As a follow up patch to commit f4b41f062c42 ("net: remove noblock parameter from skb_recv_datagram()") this patch removes the separate 'noblock' parameter for recvmsg(). Analogue to the referenced patch for skb_recv_datagram() the 'flags' and 'noblock' parameters are unnecessarily split up with e.g. err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT, flags & ~MSG_DONTWAIT, &addr_len); or in err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg, sk, msg, size, flags & MSG_DONTWAIT, flags & ~MSG_DONTWAIT, &addr_len); instead of simply using only flags all the time and check for MSG_DONTWAIT where needed (to preserve for the formerly separated no(n)block condition). Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/r/20220411124955.154876-1-socketcan@hartkopp.net Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-04-06tcp: add accessors to read/set tp->snd_cwndEric Dumazet1-4/+4
We had various bugs over the years with code breaking the assumption that tp->snd_cwnd is greater than zero. Lately, syzbot reported the WARN_ON_ONCE(!tp->prior_cwnd) added in commit 8b8a321ff72c ("tcp: fix zero cwnd in tcp_cwnd_reduction") can trigger, and without a repro we would have to spend considerable time finding the bug. Instead of complaining too late, we want to catch where and when tp->snd_cwnd is set to an illegal value. Signed-off-by: Eric Dumazet <edumazet@google.com> Suggested-by: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Link: https://lore.kernel.org/r/20220405233538.947344-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>