From patchwork Tue Jan 12 22:38:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 12015443 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5501BC433E0 for ; Tue, 12 Jan 2021 22:39:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0BB58230FC for ; Tue, 12 Jan 2021 22:39:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405895AbhALWjd (ORCPT ); Tue, 12 Jan 2021 17:39:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405909AbhALWjc (ORCPT ); Tue, 12 Jan 2021 17:39:32 -0500 Received: from mail-qt1-x849.google.com (mail-qt1-x849.google.com [IPv6:2607:f8b0:4864:20::849]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E507C061794 for ; Tue, 12 Jan 2021 14:38:52 -0800 (PST) Received: by mail-qt1-x849.google.com with SMTP id j1so54134qtd.13 for ; Tue, 12 Jan 2021 14:38:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=g3y/V6PokWg4hkIl36oGydEWQphTq8UHAbA0JVhYOtc=; b=DYH3PUKIkv3jpdsK6t048WnT7AY2L2K3LOP+5NuEkawWq3wtCHPpxQ3N6P4s0T14+M 2g+g4S/LBcp9RaLhqOgitMN8pLLCwf/kj+plLlS/VbXnGsepg6b8i/1B1VP/w5jIqjJT Hst4R2cH4ZRYci85RBEVHclRnUfVl0+hl7BCN1WXsuvLnbS4puqVarBrXxDFwvkUM2Du Yn4pFm4szyiEj5q84+C2cEszEdOfNX+TDdHSQ/uQ3JhlVZEIpnMkKabXqArE8tWIqDKR 4IYRYjKHFazskAMR2pthDC4LHZDt+eQPQh6hed7lhebl4FnG+I5AIMid1rbppudswNha DYCw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=g3y/V6PokWg4hkIl36oGydEWQphTq8UHAbA0JVhYOtc=; b=UuK7xi8HYgJPE8c2RT7hkXWCvBBXBckN2NtTc1o5DmSsF+4hfOSGngZJQyECfiGVxD BZzY02nVozE4clumnlOXGfg+RX4gQlBKrd25oVqQ/VwRR8cJLPbKoY58NhBmhtK3qCAY qbz55gt17FIn39PK8A6UWwTSLUmsO9SNZkdCBySHn/W2Zzd8iCMpEvLLgLTY116VMWDt wSnPxo9jrbbbH4T5JIgobyiYaBQ5qkQuttxMvyIt9YywI1HTzzrs4wcTag38WtroAr5p +/NuIIEuTVG2KVMKucoZ2UIROXv+UilL59LqsN/pKsQ5G4YzKu3nB5sZRq/wPo3HcWtK t1yg== X-Gm-Message-State: AOAM531WUnZTKww9/w5W7JR0Bi48P3c8ZTgjnXIhWGliUQk3IBCCJOuD vxmurfTsI4a9GopjS9etsT3mvDI= X-Google-Smtp-Source: ABdhPJzsH3g6cRMWWGMCYHpLi+HYh+6wmDLqIJg4Ltu3TPVTsI7cSZ/7ySrsqDErl7v9aoiBaF/lmns= Sender: "sdf via sendgmr" X-Received: from sdf2.svl.corp.google.com ([2620:15c:2c4:1:7220:84ff:fe09:7732]) (user=sdf job=sendgmr) by 2002:ad4:46e7:: with SMTP id h7mr1953797qvw.44.1610491131495; Tue, 12 Jan 2021 14:38:51 -0800 (PST) Date: Tue, 12 Jan 2021 14:38:44 -0800 In-Reply-To: <20210112223847.1915615-1-sdf@google.com> Message-Id: <20210112223847.1915615-2-sdf@google.com> Mime-Version: 1.0 References: <20210112223847.1915615-1-sdf@google.com> X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog Subject: [PATCH bpf-next v7 1/4] bpf: remove extra lock_sock for TCP_ZEROCOPY_RECEIVE From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, Stanislav Fomichev , Martin KaFai Lau , Song Liu , Eric Dumazet Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add custom implementation of getsockopt hook for TCP_ZEROCOPY_RECEIVE. We skip generic hooks for TCP_ZEROCOPY_RECEIVE and have a custom call in do_tcp_getsockopt using the on-stack data. This removes 3% overhead for locking/unlocking the socket. Without this patch: 3.38% 0.07% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt | --3.30%--__cgroup_bpf_run_filter_getsockopt | --0.81%--__kmalloc With the patch applied: 0.52% 0.12% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt_kern Signed-off-by: Stanislav Fomichev Cc: Martin KaFai Lau Cc: Song Liu Cc: Eric Dumazet --- include/linux/bpf-cgroup.h | 27 +++++++++-- include/linux/indirect_call_wrapper.h | 6 +++ include/net/sock.h | 2 + include/net/tcp.h | 1 + kernel/bpf/cgroup.c | 46 +++++++++++++++++++ net/ipv4/tcp.c | 14 ++++++ net/ipv4/tcp_ipv4.c | 1 + net/ipv6/tcp_ipv6.c | 1 + net/socket.c | 3 ++ .../selftests/bpf/prog_tests/sockopt_sk.c | 22 +++++++++ .../testing/selftests/bpf/progs/sockopt_sk.c | 15 ++++++ 11 files changed, 134 insertions(+), 4 deletions(-) diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index 72e69a0e1e8c..bcb2915e6124 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -147,6 +147,10 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level, int __user *optlen, int max_optlen, int retval); +int __cgroup_bpf_run_filter_getsockopt_kern(struct sock *sk, int level, + int optname, void *optval, + int *optlen, int retval); + static inline enum bpf_cgroup_storage_type cgroup_storage_type( struct bpf_map *map) { @@ -364,10 +368,23 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, ({ \ int __ret = retval; \ if (cgroup_bpf_enabled) \ - __ret = __cgroup_bpf_run_filter_getsockopt(sock, level, \ - optname, optval, \ - optlen, max_optlen, \ - retval); \ + if (!(sock)->sk_prot->bpf_bypass_getsockopt || \ + !INDIRECT_CALL_INET_1((sock)->sk_prot->bpf_bypass_getsockopt, \ + tcp_bpf_bypass_getsockopt, \ + level, optname)) \ + __ret = __cgroup_bpf_run_filter_getsockopt( \ + sock, level, optname, optval, optlen, \ + max_optlen, retval); \ + __ret; \ +}) + +#define BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sock, level, optname, optval, \ + optlen, retval) \ +({ \ + int __ret = retval; \ + if (cgroup_bpf_enabled) \ + __ret = __cgroup_bpf_run_filter_getsockopt_kern( \ + sock, level, optname, optval, optlen, retval); \ __ret; \ }) @@ -452,6 +469,8 @@ static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map, #define BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen) ({ 0; }) #define BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock, level, optname, optval, \ optlen, max_optlen, retval) ({ retval; }) +#define BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sock, level, optname, optval, \ + optlen, retval) ({ retval; }) #define BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock, level, optname, optval, optlen, \ kernel_optval) ({ 0; }) diff --git a/include/linux/indirect_call_wrapper.h b/include/linux/indirect_call_wrapper.h index 54c02c84906a..cfcfef37b2f1 100644 --- a/include/linux/indirect_call_wrapper.h +++ b/include/linux/indirect_call_wrapper.h @@ -60,4 +60,10 @@ #define INDIRECT_CALL_INET(f, f2, f1, ...) f(__VA_ARGS__) #endif +#if IS_ENABLED(CONFIG_INET) +#define INDIRECT_CALL_INET_1(f, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__) +#else +#define INDIRECT_CALL_INET_1(f, f1, ...) f(__VA_ARGS__) +#endif + #endif diff --git a/include/net/sock.h b/include/net/sock.h index bdc4323ce53c..ebf44d724845 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1174,6 +1174,8 @@ struct proto { int (*backlog_rcv) (struct sock *sk, struct sk_buff *skb); + bool (*bpf_bypass_getsockopt)(int level, + int optname); void (*release_cb)(struct sock *sk); diff --git a/include/net/tcp.h b/include/net/tcp.h index 78d13c88720f..4bb42fb19711 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -403,6 +403,7 @@ __poll_t tcp_poll(struct file *file, struct socket *sock, struct poll_table_struct *wait); int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); +bool tcp_bpf_bypass_getsockopt(int level, int optname); int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, unsigned int optlen); void tcp_set_keepalive(struct sock *sk, int val); diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 96555a8a2c54..416e7738981b 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -1486,6 +1486,52 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level, sockopt_free_buf(&ctx); return ret; } + +int __cgroup_bpf_run_filter_getsockopt_kern(struct sock *sk, int level, + int optname, void *optval, + int *optlen, int retval) +{ + struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); + struct bpf_sockopt_kern ctx = { + .sk = sk, + .level = level, + .optname = optname, + .retval = retval, + .optlen = *optlen, + .optval = optval, + .optval_end = optval + *optlen, + }; + int ret; + + /* Note that __cgroup_bpf_run_filter_getsockopt doesn't copy + * user data back into BPF buffer when reval != 0. This is + * done as an optimization to avoid extra copy, assuming + * kernel won't populate the data in case of an error. + * Here we always pass the data and memset() should + * be called if that data shouldn't be "exported". + */ + + ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT], + &ctx, BPF_PROG_RUN); + if (!ret) + return -EPERM; + + if (ctx.optlen > *optlen) + return -EFAULT; + + /* BPF programs only allowed to set retval to 0, not some + * arbitrary value. + */ + if (ctx.retval != 0 && ctx.retval != retval) + return -EFAULT; + + /* BPF programs can shrink the buffer, export the modifications. + */ + if (ctx.optlen != 0) + *optlen = ctx.optlen; + + return ctx.retval; +} #endif static ssize_t sysctl_cpy_dir(const struct ctl_dir *dir, char **bufp, diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 2267d21c73a6..d434bdac2917 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4098,6 +4098,8 @@ static int do_tcp_getsockopt(struct sock *sk, int level, return -EFAULT; lock_sock(sk); err = tcp_zerocopy_receive(sk, &zc); + err = BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sk, level, optname, + &zc, &len, err); release_sock(sk); if (len >= offsetofend(struct tcp_zerocopy_receive, err)) goto zerocopy_rcv_sk_err; @@ -4132,6 +4134,18 @@ static int do_tcp_getsockopt(struct sock *sk, int level, return 0; } +bool tcp_bpf_bypass_getsockopt(int level, int optname) +{ + /* TCP do_tcp_getsockopt has optimized getsockopt implementation + * to avoid extra socket lock for TCP_ZEROCOPY_RECEIVE. + */ + if (level == SOL_TCP && optname == TCP_ZEROCOPY_RECEIVE) + return true; + + return false; +} +EXPORT_SYMBOL(tcp_bpf_bypass_getsockopt); + int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen) { diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 58207c7769d0..8b4906980fce 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2792,6 +2792,7 @@ struct proto tcp_prot = { .shutdown = tcp_shutdown, .setsockopt = tcp_setsockopt, .getsockopt = tcp_getsockopt, + .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt, .keepalive = tcp_set_keepalive, .recvmsg = tcp_recvmsg, .sendmsg = tcp_sendmsg, diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 0e1509b02cb3..8539715ff035 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -2121,6 +2121,7 @@ struct proto tcpv6_prot = { .shutdown = tcp_shutdown, .setsockopt = tcp_setsockopt, .getsockopt = tcp_getsockopt, + .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt, .keepalive = tcp_set_keepalive, .recvmsg = tcp_recvmsg, .sendmsg = tcp_sendmsg, diff --git a/net/socket.c b/net/socket.c index 33e8b6c4e1d3..7f0617ab5437 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2126,6 +2126,9 @@ SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname, return __sys_setsockopt(fd, level, optname, optval, optlen); } +INDIRECT_CALLABLE_DECLARE(bool tcp_bpf_bypass_getsockopt(int level, + int optname)); + /* * Get a socket option. Because we don't know the option lengths we have * to pass a user mode parameter for the protocols to sort out. diff --git a/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c b/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c index b25c9c45c148..6bb18b1d8578 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c +++ b/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c @@ -11,6 +11,7 @@ static int getsetsockopt(void) char u8[4]; __u32 u32; char cc[16]; /* TCP_CA_NAME_MAX */ + struct tcp_zerocopy_receive zc; } buf = {}; socklen_t optlen; char *big_buf = NULL; @@ -154,6 +155,27 @@ static int getsetsockopt(void) goto err; } + /* TCP_ZEROCOPY_RECEIVE triggers */ + memset(&buf, 0, sizeof(buf)); + optlen = sizeof(buf.zc); + err = getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen); + if (err) { + log_err("Unexpected getsockopt(TCP_ZEROCOPY_RECEIVE) err=%d errno=%d", + err, errno); + goto err; + } + + memset(&buf, 0, sizeof(buf)); + buf.zc.address = 12345; /* rejected by BPF */ + optlen = sizeof(buf.zc); + errno = 0; + err = getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen); + if (errno != EPERM) { + log_err("Unexpected getsockopt(TCP_ZEROCOPY_RECEIVE) err=%d errno=%d", + err, errno); + goto err; + } + free(big_buf); close(fd); return 0; diff --git a/tools/testing/selftests/bpf/progs/sockopt_sk.c b/tools/testing/selftests/bpf/progs/sockopt_sk.c index 712df7b49cb1..c726f0763a13 100644 --- a/tools/testing/selftests/bpf/progs/sockopt_sk.c +++ b/tools/testing/selftests/bpf/progs/sockopt_sk.c @@ -57,6 +57,21 @@ int _getsockopt(struct bpf_sockopt *ctx) return 1; } + if (ctx->level == SOL_TCP && ctx->optname == TCP_ZEROCOPY_RECEIVE) { + /* Verify that TCP_ZEROCOPY_RECEIVE triggers. + * It has a custom implementation for performance + * reasons. + */ + + if (optval + sizeof(struct tcp_zerocopy_receive) > optval_end) + return 0; /* EPERM, bounds check */ + + if (((struct tcp_zerocopy_receive *)optval)->address != 0) + return 0; /* EPERM, unexpected data */ + + return 1; + } + if (ctx->level == SOL_IP && ctx->optname == IP_FREEBIND) { if (optval + 1 > optval_end) return 0; /* EPERM, bounds check */