From patchwork Tue Jun 30 04:33:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 1319507 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=Wnkog++K; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49ws1v2nTCz9sR4 for ; Tue, 30 Jun 2020 14:33:55 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726939AbgF3Edu (ORCPT ); Tue, 30 Jun 2020 00:33:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726268AbgF3Edu (ORCPT ); Tue, 30 Jun 2020 00:33:50 -0400 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2EC2DC061755; Mon, 29 Jun 2020 21:33:50 -0700 (PDT) Received: by mail-pj1-x1041.google.com with SMTP id f6so4885929pjq.5; Mon, 29 Jun 2020 21:33:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=7OTv1ekDxOAnqvhvLmGu2MGZBJLyFM7F84Ei7ka2OxY=; b=Wnkog++K/Pwsv+TKBNIDdJfTnoPA8wv4Yxk62/EvCdKl6VKugl13cbdqT3JkRJA3/s UzBdl6mNHjWCB6+f8RdhLM2E8n64y16FU8KaLvQl57IvBC+4E/64o6uE/j3DimA7P4vw rrNohMZuZVxK7s91fhT/YlpD/Oo29OlyeOn2BA70UbjLtabCVKpuWmPTfbrlVrOC0i3l 4oFOalceYAkGOTeasrrDQoT/28/S+pYY4f1NIdQNrhDawaUt1GlsnUR+10/g0poFLrH5 i8IgdN8fiqJPSaCsgYInw6h+rr3RsnEJOkh7D85IA8orZm9ef8Ofhm2eSIXMNmRsG5U0 ospQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=7OTv1ekDxOAnqvhvLmGu2MGZBJLyFM7F84Ei7ka2OxY=; b=iSLj4S6AfzKWiRZEgk1vVVZA6qN0m7dk/yucLc90Oo2Bsgwe5CXbAE48ogY80tqJvD 5EZ6KQXElpTqNvbUkHkFGMUbC1AyA4M466M/+Of1Bkit0qhEi1dPoRhiipegKhanpG2y GrbYonT4zI5Pt7vbH4eSe4WckdSRtwTJn31P0kaAqa5BeM8fnn+mLpriPeUWZRxUjxvE 96nMzabTQyqToqRQ0MW1wyU+kEaotUMKS7PhQYtH/1OPpIFnIPASNxEffQYQiqMz0M7v guvJiz3Cmpu+dSIMo7jb/ErXNLkFJ8Eab3f2jZWw0a66+Xf2pJC0fPyvInn0iI7VUSMB e6KQ== X-Gm-Message-State: AOAM533KWxTffxgWPnNhYLIeinDXINFz0rE0gPAFvsBhgVgJdc3+p/Q2 uxIEaSEnqmbgapifrt/N4VE= X-Google-Smtp-Source: ABdhPJw4ndWwIwDJ1NfzWndUi1csB+EhAyYpdIQGvl2303qKafRr437PWu4naoK2h1q/kkuy8NGL+g== X-Received: by 2002:a17:902:c252:: with SMTP id 18mr9579984plg.39.1593491629653; Mon, 29 Jun 2020 21:33:49 -0700 (PDT) Received: from ast-mbp.thefacebook.com ([163.114.132.7]) by smtp.gmail.com with ESMTPSA id 21sm1111234pfv.43.2020.06.29.21.33.46 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 29 Jun 2020 21:33:47 -0700 (PDT) From: Alexei Starovoitov To: davem@davemloft.net Cc: daniel@iogearbox.net, paulmck@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com Subject: [PATCH v5 bpf-next 1/5] bpf: Remove redundant synchronize_rcu. Date: Mon, 29 Jun 2020 21:33:39 -0700 Message-Id: <20200630043343.53195-2-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.13.5 In-Reply-To: <20200630043343.53195-1-alexei.starovoitov@gmail.com> References: <20200630043343.53195-1-alexei.starovoitov@gmail.com> Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Alexei Starovoitov bpf_free_used_maps() or close(map_fd) will trigger map_free callback. bpf_free_used_maps() is called after bpf prog is no longer executing: bpf_prog_put->call_rcu->bpf_prog_free->bpf_free_used_maps. Hence there is no need to call synchronize_rcu() to protect map elements. Note that hash_of_maps and array_of_maps update/delete inner maps via sys_bpf() that calls maybe_wait_bpf_programs() and synchronize_rcu(). Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Acked-by: Paul E. McKenney --- kernel/bpf/arraymap.c | 9 --------- kernel/bpf/hashtab.c | 8 +++----- kernel/bpf/lpm_trie.c | 5 ----- kernel/bpf/queue_stack_maps.c | 7 ------- kernel/bpf/reuseport_array.c | 2 -- kernel/bpf/ringbuf.c | 7 ------- kernel/bpf/stackmap.c | 3 --- 7 files changed, 3 insertions(+), 38 deletions(-) diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index ec5cd11032aa..c66e8273fccd 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -386,13 +386,6 @@ static void array_map_free(struct bpf_map *map) { struct bpf_array *array = container_of(map, struct bpf_array, map); - /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0, - * so the programs (can be more than one that used this map) were - * disconnected from events. Wait for outstanding programs to complete - * and free the array - */ - synchronize_rcu(); - if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) bpf_array_free_percpu(array); @@ -546,8 +539,6 @@ static void fd_array_map_free(struct bpf_map *map) struct bpf_array *array = container_of(map, struct bpf_array, map); int i; - synchronize_rcu(); - /* make sure it's empty */ for (i = 0; i < array->map.max_entries; i++) BUG_ON(array->ptrs[i] != NULL); diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index acd06081d81d..d4378d7d442b 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -1290,12 +1290,10 @@ static void htab_map_free(struct bpf_map *map) { struct bpf_htab *htab = container_of(map, struct bpf_htab, map); - /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0, - * so the programs (can be more than one that used this map) were - * disconnected from events. Wait for outstanding critical sections in - * these programs to complete + /* bpf_free_used_maps() or close(map_fd) will trigger this map_free callback. + * bpf_free_used_maps() is called after bpf prog is no longer executing. + * There is no need to synchronize_rcu() here to protect map elements. */ - synchronize_rcu(); /* some of free_htab_elem() callbacks for elements of this map may * not have executed. Wait for them. diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index 1abd4e3f906d..44474bf3ab7a 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -589,11 +589,6 @@ static void trie_free(struct bpf_map *map) struct lpm_trie_node __rcu **slot; struct lpm_trie_node *node; - /* Wait for outstanding programs to complete - * update/lookup/delete/get_next_key and free the trie. - */ - synchronize_rcu(); - /* Always start at the root and walk down to a node that has no * children. Then free that node, nullify its reference in the parent * and start over. diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c index 80c66a6d7c54..44184f82916a 100644 --- a/kernel/bpf/queue_stack_maps.c +++ b/kernel/bpf/queue_stack_maps.c @@ -101,13 +101,6 @@ static void queue_stack_map_free(struct bpf_map *map) { struct bpf_queue_stack *qs = bpf_queue_stack(map); - /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0, - * so the programs (can be more than one that used this map) were - * disconnected from events. Wait for outstanding critical sections in - * these programs to complete - */ - synchronize_rcu(); - bpf_map_area_free(qs); } diff --git a/kernel/bpf/reuseport_array.c b/kernel/bpf/reuseport_array.c index a09922f656e4..3625c4fcc65c 100644 --- a/kernel/bpf/reuseport_array.c +++ b/kernel/bpf/reuseport_array.c @@ -96,8 +96,6 @@ static void reuseport_array_free(struct bpf_map *map) struct sock *sk; u32 i; - synchronize_rcu(); - /* * ops->map_*_elem() will not be able to access this * array now. Hence, this function only races with diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c index dbf37aff4827..13a8d3967e07 100644 --- a/kernel/bpf/ringbuf.c +++ b/kernel/bpf/ringbuf.c @@ -215,13 +215,6 @@ static void ringbuf_map_free(struct bpf_map *map) { struct bpf_ringbuf_map *rb_map; - /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0, - * so the programs (can be more than one that used this map) were - * disconnected from events. Wait for outstanding critical sections in - * these programs to complete - */ - synchronize_rcu(); - rb_map = container_of(map, struct bpf_ringbuf_map, map); bpf_ringbuf_free(rb_map->rb); kfree(rb_map); diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 27dc9b1b08a5..071f98d0f7c6 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -604,9 +604,6 @@ static void stack_map_free(struct bpf_map *map) { struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map); - /* wait for bpf programs to complete before freeing stack map */ - synchronize_rcu(); - bpf_map_area_free(smap->elems); pcpu_freelist_destroy(&smap->freelist); bpf_map_area_free(smap); From patchwork Tue Jun 30 04:33:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 1319508 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=F3qo9GH+; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49ws1w05Lwz9sDX for ; Tue, 30 Jun 2020 14:33:56 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727815AbgF3Edy (ORCPT ); Tue, 30 Jun 2020 00:33:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726268AbgF3Edw (ORCPT ); Tue, 30 Jun 2020 00:33:52 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1BCF9C061755; Mon, 29 Jun 2020 21:33:52 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id h4so1876565plt.9; Mon, 29 Jun 2020 21:33:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Es0+rCkq4TE7OdkGx5wMr379ruHlMMEm0ekHSzJL9Uc=; b=F3qo9GH+H0NRcuqsJpyIS2zB9DHVkRSsx7sCfasAQvDh5Q6kTRqg/FQUmgZ2wvy2qt xsNa1mgd1RLJHJDGsaoYwRGte52U+sTCdMC3fvX01gI6H182XOYhY49EL1a8m2P4vhcS 7XYLyABFYcV0F36GiNwMcqhSQvMBKE0D5vFw5MCPkfD/9eSED/h4sNPkWafRN7NG469/ GhmP2RMbavW67ZMFqx07FV2NF5MQmstAILojkEW/JLfK9KKCUXNAoiiAw78Xc8MST9Kr Ldq3ZhW6tcBP/aDCrW68bB5mCNHEUuHo4awrZ9AVXUIOL6TRqBEQul5PnCvdNgZpZSSl 1uAg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=Es0+rCkq4TE7OdkGx5wMr379ruHlMMEm0ekHSzJL9Uc=; b=nNdEZif9vnKuQB+ljAb26yGVdlBwe+VX+wCO2VgROqqJn5m/KGOorZenEX7mKCOZsx uNKDQtZrnxTqpKuRXlUoL+ObHuOqDuy6MusfQKki11QUFH6gOhACmU4J9W7VeAqImIh9 rzxf3P0CpB91FZiaViW7CyCcRYgPXxhNg152C4JJCAOTbgeN74yGCkuwmvN8WsN97up0 KC4dsvaupNhooYcFLCx5KEG62sFrz3UQVctYhqZR9pQFJUJH0WbxD5z4UQOi8br0+6jZ tNaHCgfs1nRKEGaKCFnzIZjX4yzxVhTfR0VL9pL5TvwMF1Yxstgub8wPOPvsMCshTXrD B5Hg== X-Gm-Message-State: AOAM533w83UW/et1Oz3otLr7KpCAKKTCaA1YgaPnVX5l85tH5mj2H5iT SUltAeUh7lq4w2P2F0xLNtg= X-Google-Smtp-Source: ABdhPJyozXnWxS2BdGqJytvFMpGg5lbrmLq0IzPu0aCBNec/w4ge7MmI6XZ78tCfn28OkA9e+tx9hQ== X-Received: by 2002:a17:902:8a8f:: with SMTP id p15mr16261327plo.172.1593491631493; Mon, 29 Jun 2020 21:33:51 -0700 (PDT) Received: from ast-mbp.thefacebook.com ([163.114.132.7]) by smtp.gmail.com with ESMTPSA id 21sm1111234pfv.43.2020.06.29.21.33.49 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 29 Jun 2020 21:33:50 -0700 (PDT) From: Alexei Starovoitov To: davem@davemloft.net Cc: daniel@iogearbox.net, paulmck@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com Subject: [PATCH v5 bpf-next 2/5] bpf: Introduce sleepable BPF programs Date: Mon, 29 Jun 2020 21:33:40 -0700 Message-Id: <20200630043343.53195-3-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.13.5 In-Reply-To: <20200630043343.53195-1-alexei.starovoitov@gmail.com> References: <20200630043343.53195-1-alexei.starovoitov@gmail.com> Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Alexei Starovoitov Introduce sleepable BPF programs that can request such property for themselves via BPF_F_SLEEPABLE flag at program load time. In such case they will be able to use helpers like bpf_copy_from_user() that might sleep. At present only fentry/fexit/fmod_ret and lsm programs can request to be sleepable and only when they are attached to kernel functions that are known to allow sleeping. The non-sleepable programs are relying on implicit rcu_read_lock() and migrate_disable() to protect life time of programs, maps that they use and per-cpu kernel structures used to pass info between bpf programs and the kernel. The sleepable programs cannot be enclosed into rcu_read_lock(). migrate_disable() maps to preempt_disable() in non-RT kernels, so the progs should not be enclosed in migrate_disable() as well. Therefore rcu_read_lock_trace is used to protect the life time of sleepable progs. There are many networking and tracing program types. In many cases the 'struct bpf_prog *' pointer itself is rcu protected within some other kernel data structure and the kernel code is using rcu_dereference() to load that program pointer and call BPF_PROG_RUN() on it. All these cases are not touched. Instead sleepable bpf programs are allowed with bpf trampoline only. The program pointers are hard-coded into generated assembly of bpf trampoline and synchronize_rcu_tasks_trace() is used to protect the life time of the program. The same trampoline can hold both sleepable and non-sleepable progs. When rcu_read_lock_trace is held it means that some sleepable bpf program is running from bpf trampoline. Those programs can use bpf arrays and preallocated hash/lru maps. These map types are waiting on programs to complete via synchronize_rcu_tasks_trace(); Updates to trampoline now has to do synchronize_rcu_tasks_trace() and synchronize_rcu_tasks() to wait for sleepable progs to finish and for trampoline assembly to finish. This is the first step of introducing sleepable progs. After that dynamically allocated hash maps can be allowed. All map elements would have to be rcu_trace protected instead of normal rcu. per-cpu maps will be allowed. Either via the following pattern: void *elem = bpf_map_lookup_elem(map, key); if (elem) { // access elem bpf_map_release_elem(map, elem); } where modified lookup() helper will do migrate_disable() and new bpf_map_release_elem() will do corresponding migrate_enable(). Or explicit bpf_migrate_disable/enable() helpers will be introduced. Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Acked-by: Paul E. McKenney --- arch/x86/net/bpf_jit_comp.c | 32 ++++++++++++------ include/linux/bpf.h | 3 ++ include/uapi/linux/bpf.h | 8 +++++ init/Kconfig | 1 + kernel/bpf/arraymap.c | 1 + kernel/bpf/hashtab.c | 12 +++---- kernel/bpf/syscall.c | 13 +++++-- kernel/bpf/trampoline.c | 28 +++++++++++++-- kernel/bpf/verifier.c | 62 +++++++++++++++++++++++++++++++++- tools/include/uapi/linux/bpf.h | 8 +++++ 10 files changed, 144 insertions(+), 24 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 42b6709e6dc7..7d9ea7b41c71 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1379,10 +1379,15 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, u8 *prog = *pprog; int cnt = 0; - if (emit_call(&prog, __bpf_prog_enter, prog)) - return -EINVAL; - /* remember prog start time returned by __bpf_prog_enter */ - emit_mov_reg(&prog, true, BPF_REG_6, BPF_REG_0); + if (p->aux->sleepable) { + if (emit_call(&prog, __bpf_prog_enter_sleepable, prog)) + return -EINVAL; + } else { + if (emit_call(&prog, __bpf_prog_enter, prog)) + return -EINVAL; + /* remember prog start time returned by __bpf_prog_enter */ + emit_mov_reg(&prog, true, BPF_REG_6, BPF_REG_0); + } /* arg1: lea rdi, [rbp - stack_size] */ EMIT4(0x48, 0x8D, 0x7D, -stack_size); @@ -1402,13 +1407,18 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, if (mod_ret) emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); - /* arg1: mov rdi, progs[i] */ - emit_mov_imm64(&prog, BPF_REG_1, (long) p >> 32, - (u32) (long) p); - /* arg2: mov rsi, rbx <- start time in nsec */ - emit_mov_reg(&prog, true, BPF_REG_2, BPF_REG_6); - if (emit_call(&prog, __bpf_prog_exit, prog)) - return -EINVAL; + if (p->aux->sleepable) { + if (emit_call(&prog, __bpf_prog_exit_sleepable, prog)) + return -EINVAL; + } else { + /* arg1: mov rdi, progs[i] */ + emit_mov_imm64(&prog, BPF_REG_1, (long) p >> 32, + (u32) (long) p); + /* arg2: mov rsi, rbx <- start time in nsec */ + emit_mov_reg(&prog, true, BPF_REG_2, BPF_REG_6); + if (emit_call(&prog, __bpf_prog_exit, prog)) + return -EINVAL; + } *pprog = prog; return 0; diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 3d2ade703a35..e2b1581b2195 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -495,6 +495,8 @@ int arch_prepare_bpf_trampoline(void *image, void *image_end, /* these two functions are called from generated trampoline */ u64 notrace __bpf_prog_enter(void); void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start); +void notrace __bpf_prog_enter_sleepable(void); +void notrace __bpf_prog_exit_sleepable(void); struct bpf_ksym { unsigned long start; @@ -687,6 +689,7 @@ struct bpf_prog_aux { bool offload_requested; bool attach_btf_trace; /* true if attaching to BTF-enabled raw tp */ bool func_proto_unreliable; + bool sleepable; enum bpf_tramp_prog_type trampoline_prog_type; struct bpf_trampoline *trampoline; struct hlist_node tramp_hlist; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 0cb8ec948816..73f9e3f84b77 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -332,6 +332,14 @@ enum bpf_link_type { /* The verifier internal test flag. Behavior is undefined */ #define BPF_F_TEST_STATE_FREQ (1U << 3) +/* If BPF_F_SLEEPABLE is used in BPF_PROG_LOAD command, the verifier will + * restrict map and helper usage for such programs. Sleepable BPF programs can + * only be attached to hooks where kernel execution context allows sleeping. + * Such programs are allowed to use helpers that may sleep like + * bpf_copy_from_user(). + */ +#define BPF_F_SLEEPABLE (1U << 4) + /* When BPF ldimm64's insn[0].src_reg != 0 then this can have * two extensions: * diff --git a/init/Kconfig b/init/Kconfig index a46aa8f3174d..62687583f822 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1663,6 +1663,7 @@ config BPF_SYSCALL bool "Enable bpf() system call" select BPF select IRQ_WORK + select TASKS_TRACE_RCU default n help Enable the bpf() system call that allows to manipulate eBPF diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index c66e8273fccd..b07abcd58785 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -10,6 +10,7 @@ #include #include #include +#include #include "map_in_map.h" diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index d4378d7d442b..65a7919e189d 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -9,6 +9,7 @@ #include #include #include +#include #include "percpu_freelist.h" #include "bpf_lru_list.h" #include "map_in_map.h" @@ -577,8 +578,7 @@ static void *__htab_map_lookup_elem(struct bpf_map *map, void *key) struct htab_elem *l; u32 hash, key_size; - /* Must be called with rcu_read_lock. */ - WARN_ON_ONCE(!rcu_read_lock_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); key_size = map->key_size; @@ -935,7 +935,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value, /* unknown flags */ return -EINVAL; - WARN_ON_ONCE(!rcu_read_lock_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); key_size = map->key_size; @@ -1026,7 +1026,7 @@ static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value, /* unknown flags */ return -EINVAL; - WARN_ON_ONCE(!rcu_read_lock_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); key_size = map->key_size; @@ -1214,7 +1214,7 @@ static int htab_map_delete_elem(struct bpf_map *map, void *key) u32 hash, key_size; int ret = -ENOENT; - WARN_ON_ONCE(!rcu_read_lock_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); key_size = map->key_size; @@ -1246,7 +1246,7 @@ static int htab_lru_map_delete_elem(struct bpf_map *map, void *key) u32 hash, key_size; int ret = -ENOENT; - WARN_ON_ONCE(!rcu_read_lock_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); key_size = map->key_size; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 8da159936bab..782b2b029539 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -29,6 +29,7 @@ #include #include #include +#include #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ @@ -1728,10 +1729,14 @@ static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) btf_put(prog->aux->btf); bpf_prog_free_linfo(prog); - if (deferred) - call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); - else + if (deferred) { + if (prog->aux->sleepable) + call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); + else + call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); + } else { __bpf_prog_put_rcu(&prog->aux->rcu); + } } static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock) @@ -2096,6 +2101,7 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | BPF_F_ANY_ALIGNMENT | BPF_F_TEST_STATE_FREQ | + BPF_F_SLEEPABLE | BPF_F_TEST_RND_HI32)) return -EINVAL; @@ -2151,6 +2157,7 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) } prog->aux->offload_requested = !!attr->prog_ifindex; + prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE; err = security_bpf_prog_alloc(prog->aux); if (err) diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 9be85aa4ec5f..c2b76545153c 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -7,6 +7,8 @@ #include #include #include +#include +#include /* dummy _ops. The verifier will operate on target program's ops. */ const struct bpf_verifier_ops bpf_extension_verifier_ops = { @@ -210,9 +212,12 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr) * updates to trampoline would change the code from underneath the * preempted task. Hence wait for tasks to voluntarily schedule or go * to userspace. + * The same trampoline can hold both sleepable and non-sleepable progs. + * synchronize_rcu_tasks_trace() is needed to make sure all sleepable + * programs finish executing. + * Wait for these two grace periods together. */ - - synchronize_rcu_tasks(); + synchronize_rcu_mult(call_rcu_tasks, call_rcu_tasks_trace); err = arch_prepare_bpf_trampoline(new_image, new_image + PAGE_SIZE / 2, &tr->func.model, flags, tprogs, @@ -344,7 +349,14 @@ void bpf_trampoline_put(struct bpf_trampoline *tr) if (WARN_ON_ONCE(!hlist_empty(&tr->progs_hlist[BPF_TRAMP_FEXIT]))) goto out; bpf_image_ksym_del(&tr->ksym); - /* wait for tasks to get out of trampoline before freeing it */ + /* This code will be executed when all bpf progs (both sleepable and + * non-sleepable) went through + * bpf_prog_put()->call_rcu[_tasks_trace]()->bpf_prog_free_deferred(). + * Hence no need for another synchronize_rcu_tasks_trace() here, + * but synchronize_rcu_tasks() is still needed, since trampoline + * may not have had any sleepable programs and we need to wait + * for tasks to get out of trampoline code before freeing it. + */ synchronize_rcu_tasks(); bpf_jit_free_exec(tr->image); hlist_del(&tr->hlist); @@ -394,6 +406,16 @@ void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start) rcu_read_unlock(); } +void notrace __bpf_prog_enter_sleepable(void) +{ + rcu_read_lock_trace(); +} + +void notrace __bpf_prog_exit_sleepable(void) +{ + rcu_read_unlock_trace(); +} + int __weak arch_prepare_bpf_trampoline(void *image, void *image_end, const struct btf_func_model *m, u32 flags, diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 7de98906ddf4..05aa990ba9a4 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -9112,6 +9112,23 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env, return -EINVAL; } + if (prog->aux->sleepable) + switch (map->map_type) { + case BPF_MAP_TYPE_HASH: + case BPF_MAP_TYPE_LRU_HASH: + case BPF_MAP_TYPE_ARRAY: + if (!is_preallocated_map(map)) { + verbose(env, + "Sleepable programs can only use preallocated hash maps\n"); + return -EINVAL; + } + break; + default: + verbose(env, + "Sleepable programs can only use array and hash maps\n"); + return -EINVAL; + } + return 0; } @@ -10722,6 +10739,22 @@ static int check_attach_modify_return(struct bpf_prog *prog, unsigned long addr) return -EINVAL; } +/* list of non-sleepable kernel functions that are otherwise + * available to attach by bpf_lsm or fmod_ret progs. + */ +static int check_sleepable_blacklist(unsigned long addr) +{ +#ifdef CONFIG_BPF_LSM + if (addr == (long)bpf_lsm_task_free) + return -EINVAL; +#endif +#ifdef CONFIG_SECURITY + if (addr == (long)security_task_free) + return -EINVAL; +#endif + return 0; +} + static int check_attach_btf_id(struct bpf_verifier_env *env) { struct bpf_prog *prog = env->prog; @@ -10739,6 +10772,12 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) long addr; u64 key; + if (prog->aux->sleepable && prog->type != BPF_PROG_TYPE_TRACING && + prog->type != BPF_PROG_TYPE_LSM) { + verbose(env, "Only fentry/fexit/fmod_ret and lsm programs can be sleepable\n"); + return -EINVAL; + } + if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) return check_struct_ops_btf_id(env); @@ -10952,8 +10991,29 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) if (ret) verbose(env, "%s() is not modifiable\n", prog->aux->attach_func_name); + } else if (prog->aux->sleepable) { + switch (prog->type) { + case BPF_PROG_TYPE_TRACING: + /* fentry/fexit progs can be sleepable only if they are + * attached to ALLOW_ERROR_INJECTION or security_*() funcs. + */ + ret = check_attach_modify_return(prog, addr); + if (!ret) + ret = check_sleepable_blacklist(addr); + break; + case BPF_PROG_TYPE_LSM: + /* LSM progs check that they are attached to bpf_lsm_*() funcs + * which are sleepable too. + */ + ret = check_sleepable_blacklist(addr); + break; + default: + break; + } + if (ret) + verbose(env, "%s is not sleepable\n", + prog->aux->attach_func_name); } - if (ret) goto out; tr->func.addr = (void *)addr; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 0cb8ec948816..73f9e3f84b77 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -332,6 +332,14 @@ enum bpf_link_type { /* The verifier internal test flag. Behavior is undefined */ #define BPF_F_TEST_STATE_FREQ (1U << 3) +/* If BPF_F_SLEEPABLE is used in BPF_PROG_LOAD command, the verifier will + * restrict map and helper usage for such programs. Sleepable BPF programs can + * only be attached to hooks where kernel execution context allows sleeping. + * Such programs are allowed to use helpers that may sleep like + * bpf_copy_from_user(). + */ +#define BPF_F_SLEEPABLE (1U << 4) + /* When BPF ldimm64's insn[0].src_reg != 0 then this can have * two extensions: * From patchwork Tue Jun 30 04:33:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 1319512 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=grTExM7X; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49ws1y2Xwfz9sRN for ; Tue, 30 Jun 2020 14:33:58 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728282AbgF3Ed5 (ORCPT ); Tue, 30 Jun 2020 00:33:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727885AbgF3Edy (ORCPT ); Tue, 30 Jun 2020 00:33:54 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30578C061755; Mon, 29 Jun 2020 21:33:54 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id 35so7976459ple.0; Mon, 29 Jun 2020 21:33:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=+4fMSpntLvSOLWBtcAoJWegH80p1FYzcqwVUArAZAf0=; b=grTExM7XeE+zSyvhFWeiE5Ltj+VtdrxIr5b7x5lbMTkWBgG5l16fjl6AAAroHRxAAC 5bB4hT2pz2EmT7C/TGgzozYi0iq5HQdXixVP470vkAS4FL2t+Xlqh4NJhLIufxuOramp ADtMtu9L8YF2IM6vbZ8E4w8fkDTbRpP+ellm8vK52YuxyM5HTw10ysz9HsNsFK0zABVN spEID88/y3QnrVgk2MqlM6IKeN1+Nyst/sQEaaopJPXGaveidteVGRhSv6p1K6NmW0+M 8QKtuCRu8Dy58+2jkwnmJf/QFP9ZWkH4s/9mPj4eHTCCwB/LTUp4pteDLMGWM67PGl/C G+3Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=+4fMSpntLvSOLWBtcAoJWegH80p1FYzcqwVUArAZAf0=; b=cSpmpeY+5UXMj22R7LC4jm39Qwo8RUXd3qdUUfh6d/9JasMl+lA6LcxMqqi2vJvsYV 76eDS6Dke6YiMxhHubs564fPLx09B0WOJ3YJbXSHUItWoCfgpXVTDzBKcgaQWYVjqzGW cCTwgad/DbuPBLVQtYBL+LH7gF3EwOoA9ZUgKKOOWeYyFM3L8vpQgLG8YUH0L7S5kp8T uJeaoZN/ZHvE3G/totMP92E4SrW1R02wZERiYbRtB44RNaOiQ47HPmYxOBloDWRCqhCu v/TYg950sy3am6td5Gqi+s6opSuM9SHA16nYTO8DLW54cUvZ1UwUnHavUlOGuEXftH9m P0rg== X-Gm-Message-State: AOAM531USDS1LNgYfHeZDWuumFrycNOOVrqXyZj+YizypJglolEblAaL 5Ok7Sw6XWkB6L3mHGVhW5Mc= X-Google-Smtp-Source: ABdhPJxTQkE/Yk3A3DX9tq1sw4QqoIGJeX+/YwThybjOFUZ08lWUovIqGZ0g7/O/Pyap4cWXKkRTbQ== X-Received: by 2002:a17:90a:c5:: with SMTP id v5mr20781003pjd.192.1593491633715; Mon, 29 Jun 2020 21:33:53 -0700 (PDT) Received: from ast-mbp.thefacebook.com ([163.114.132.7]) by smtp.gmail.com with ESMTPSA id 21sm1111234pfv.43.2020.06.29.21.33.51 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 29 Jun 2020 21:33:52 -0700 (PDT) From: Alexei Starovoitov To: davem@davemloft.net Cc: daniel@iogearbox.net, paulmck@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com Subject: [PATCH v5 bpf-next 3/5] bpf: Add bpf_copy_from_user() helper. Date: Mon, 29 Jun 2020 21:33:41 -0700 Message-Id: <20200630043343.53195-4-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.13.5 In-Reply-To: <20200630043343.53195-1-alexei.starovoitov@gmail.com> References: <20200630043343.53195-1-alexei.starovoitov@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Alexei Starovoitov Sleepable BPF programs can now use copy_from_user() to access user memory. Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Acked-by: KP Singh --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 11 ++++++++++- kernel/bpf/helpers.c | 22 ++++++++++++++++++++++ kernel/trace/bpf_trace.c | 2 ++ tools/include/uapi/linux/bpf.h | 11 ++++++++++- 5 files changed, 45 insertions(+), 2 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index e2b1581b2195..c9f27d5fdb7c 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1657,6 +1657,7 @@ extern const struct bpf_func_proto bpf_skc_to_tcp_sock_proto; extern const struct bpf_func_proto bpf_skc_to_tcp_timewait_sock_proto; extern const struct bpf_func_proto bpf_skc_to_tcp_request_sock_proto; extern const struct bpf_func_proto bpf_skc_to_udp6_sock_proto; +extern const struct bpf_func_proto bpf_copy_from_user_proto; const struct bpf_func_proto *bpf_tracing_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 73f9e3f84b77..6b347454dedc 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3293,6 +3293,13 @@ union bpf_attr { * Dynamically cast a *sk* pointer to a *udp6_sock* pointer. * Return * *sk* if casting is valid, or NULL otherwise. + * + * long bpf_copy_from_user(void *dst, u32 size, const void *user_ptr) + * Description + * Read *size* bytes from user space address *user_ptr* and store + * the data in *dst*. This is a wrapper of copy_from_user(). + * Return + * 0 on success, or a negative error in case of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3435,7 +3442,9 @@ union bpf_attr { FN(skc_to_tcp_sock), \ FN(skc_to_tcp_timewait_sock), \ FN(skc_to_tcp_request_sock), \ - FN(skc_to_udp6_sock), + FN(skc_to_udp6_sock), \ + FN(copy_from_user), \ + /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index be43ab3e619f..5cc7425ee476 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -601,6 +601,28 @@ const struct bpf_func_proto bpf_event_output_data_proto = { .arg5_type = ARG_CONST_SIZE_OR_ZERO, }; +BPF_CALL_3(bpf_copy_from_user, void *, dst, u32, size, + const void __user *, user_ptr) +{ + int ret = copy_from_user(dst, user_ptr, size); + + if (unlikely(ret)) { + memset(dst, 0, size); + ret = -EFAULT; + } + + return ret; +} + +const struct bpf_func_proto bpf_copy_from_user_proto = { + .func = bpf_copy_from_user, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_UNINIT_MEM, + .arg2_type = ARG_CONST_SIZE_OR_ZERO, + .arg3_type = ARG_ANYTHING, +}; + const struct bpf_func_proto bpf_get_current_task_proto __weak; const struct bpf_func_proto bpf_probe_read_user_proto __weak; const struct bpf_func_proto bpf_probe_read_user_str_proto __weak; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 5d59dda5f661..96121fa7f7e6 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1137,6 +1137,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_ringbuf_query_proto; case BPF_FUNC_jiffies64: return &bpf_jiffies64_proto; + case BPF_FUNC_copy_from_user: + return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL; default: return NULL; } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 73f9e3f84b77..6b347454dedc 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3293,6 +3293,13 @@ union bpf_attr { * Dynamically cast a *sk* pointer to a *udp6_sock* pointer. * Return * *sk* if casting is valid, or NULL otherwise. + * + * long bpf_copy_from_user(void *dst, u32 size, const void *user_ptr) + * Description + * Read *size* bytes from user space address *user_ptr* and store + * the data in *dst*. This is a wrapper of copy_from_user(). + * Return + * 0 on success, or a negative error in case of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3435,7 +3442,9 @@ union bpf_attr { FN(skc_to_tcp_sock), \ FN(skc_to_tcp_timewait_sock), \ FN(skc_to_tcp_request_sock), \ - FN(skc_to_udp6_sock), + FN(skc_to_udp6_sock), \ + FN(copy_from_user), \ + /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call From patchwork Tue Jun 30 04:33:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 1319514 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=aIvaGz23; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49ws2171QMz9sR4 for ; Tue, 30 Jun 2020 14:34:01 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728326AbgF3EeA (ORCPT ); Tue, 30 Jun 2020 00:34:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726268AbgF3Ed4 (ORCPT ); Tue, 30 Jun 2020 00:33:56 -0400 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0CAD4C061755; Mon, 29 Jun 2020 21:33:56 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id x3so3330658pfo.9; Mon, 29 Jun 2020 21:33:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=I5Dv5raHq6PKZyEpvvq0aeWAhucJ0jOmmbBdZJh0B1Y=; b=aIvaGz23E8eE8IwaaJj7UYpCXvcxyWUQN4hv0BwmYUPiUqSN44+BtyCazpizO9Pk6R DVCxtp9LrBlNJUFesBTVBdBesOnTqfR7k7MUvC3xX7iYO8B3ULS8pOtZVPL3DSzdrGte iR2l5M4rDe0feTbPiHIqN6AdlOYdls9ktk30VZNqJG2TUU0iYsf9Ghox7AsXzmndB394 TwH8VEWStwZTOD412bC96945OLAX/iJruSnUX0cOkszbU2cCjB4oaRr9awG5pyK1XU+y VfDsWXyWBgjqCey9eCHixeCeGwEIjJ0/zG1HlIKgBBbz1CNAKSJhF6ck3sxoajhT+Txt qsQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=I5Dv5raHq6PKZyEpvvq0aeWAhucJ0jOmmbBdZJh0B1Y=; b=gCN8SM1I4aUWxYtbAqGlHumfjEYCorc0HXnriTPKHEUF9psp/eHWs6BvjIjwVfJ4/J gXI0RjT+D9OAjapdL7/iWoBcYWyhV2qf6XdwgVrMDbNncreK4Gy8dO0xu2uWOiViOIcf 1epRD+pxGHH0cgwk69OVuRwKVYwBfqzzIjMm1ezN5pOhtgFU5PLN5iGFinW6vkXmH+a9 JoMLAPSaBRwEDnU8LEmCdTBm9BCrRM27QdinXsn1hzA02lEvKbzpZvPZfWOekiYJyH4I IhDmreejuIqcdHKLoozGqSmkCVspZe3mUP8J0l3axDEG42qYzNXcD/IjdCEwzDYF4RCq G4yw== X-Gm-Message-State: AOAM532A8mK6+A7S8wt7gZ8qtwpu7ahQrGW/+ozzZMSx7k5zfwUm2yz4 Zm8gYK3kDvc+iWqvIbu2slCwL89M X-Google-Smtp-Source: ABdhPJyfiguaqTfVEZKMdo0nmXJFXA16VZk1kZVKG/ZkQsXrP13vSuu2xBkFNwMnfeqr11LD4CLCjA== X-Received: by 2002:a63:d30a:: with SMTP id b10mr13084460pgg.430.1593491635597; Mon, 29 Jun 2020 21:33:55 -0700 (PDT) Received: from ast-mbp.thefacebook.com ([163.114.132.7]) by smtp.gmail.com with ESMTPSA id 21sm1111234pfv.43.2020.06.29.21.33.53 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 29 Jun 2020 21:33:54 -0700 (PDT) From: Alexei Starovoitov To: davem@davemloft.net Cc: daniel@iogearbox.net, paulmck@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com Subject: [PATCH v5 bpf-next 4/5] libbpf: support sleepable progs Date: Mon, 29 Jun 2020 21:33:42 -0700 Message-Id: <20200630043343.53195-5-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.13.5 In-Reply-To: <20200630043343.53195-1-alexei.starovoitov@gmail.com> References: <20200630043343.53195-1-alexei.starovoitov@gmail.com> Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Alexei Starovoitov Pass request to load program as sleepable via ".s" suffix in the section name. If it happens in the future that all map types and helpers are allowed with BPF_F_SLEEPABLE flag "fmod_ret/" and "lsm/" can be aliased to "fmod_ret.s/" and "lsm.s/" to make all lsm and fmod_ret programs sleepable by default. The fentry and fexit programs would always need to have sleepable vs non-sleepable distinction, since not all fentry/fexit progs will be attached to sleepable kernel functions. Signed-off-by: Alexei Starovoitov Acked-by: KP Singh Acked-by: Andrii Nakryiko --- tools/lib/bpf/libbpf.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 4ea7f4f1a691..c2f054fde30f 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -209,6 +209,7 @@ struct bpf_sec_def { bool is_exp_attach_type_optional; bool is_attachable; bool is_attach_btf; + bool is_sleepable; attach_fn_t attach_fn; }; @@ -5626,6 +5627,8 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, /* couldn't guess, but user might manually specify */ continue; + if (prog->sec_def->is_sleepable) + prog->prog_flags |= BPF_F_SLEEPABLE; bpf_program__set_type(prog, prog->sec_def->prog_type); bpf_program__set_expected_attach_type(prog, prog->sec_def->expected_attach_type); @@ -6893,6 +6896,21 @@ static const struct bpf_sec_def section_defs[] = { .expected_attach_type = BPF_TRACE_FEXIT, .is_attach_btf = true, .attach_fn = attach_trace), + SEC_DEF("fentry.s/", TRACING, + .expected_attach_type = BPF_TRACE_FENTRY, + .is_attach_btf = true, + .is_sleepable = true, + .attach_fn = attach_trace), + SEC_DEF("fmod_ret.s/", TRACING, + .expected_attach_type = BPF_MODIFY_RETURN, + .is_attach_btf = true, + .is_sleepable = true, + .attach_fn = attach_trace), + SEC_DEF("fexit.s/", TRACING, + .expected_attach_type = BPF_TRACE_FEXIT, + .is_attach_btf = true, + .is_sleepable = true, + .attach_fn = attach_trace), SEC_DEF("freplace/", EXT, .is_attach_btf = true, .attach_fn = attach_trace), @@ -6900,6 +6918,11 @@ static const struct bpf_sec_def section_defs[] = { .is_attach_btf = true, .expected_attach_type = BPF_LSM_MAC, .attach_fn = attach_lsm), + SEC_DEF("lsm.s/", LSM, + .is_attach_btf = true, + .is_sleepable = true, + .expected_attach_type = BPF_LSM_MAC, + .attach_fn = attach_lsm), SEC_DEF("iter/", TRACING, .expected_attach_type = BPF_TRACE_ITER, .is_attach_btf = true, @@ -7614,7 +7637,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, prog->prog_ifindex = attr->ifindex; prog->log_level = attr->log_level; - prog->prog_flags = attr->prog_flags; + prog->prog_flags |= attr->prog_flags; if (!first_prog) first_prog = prog; } From patchwork Tue Jun 30 04:33:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 1319515 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=J4AFeZiT; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49ws222Knsz9sRN for ; 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Mon, 29 Jun 2020 21:33:56 -0700 (PDT) From: Alexei Starovoitov To: davem@davemloft.net Cc: daniel@iogearbox.net, paulmck@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com Subject: [PATCH v5 bpf-next 5/5] selftests/bpf: Add sleepable tests Date: Mon, 29 Jun 2020 21:33:43 -0700 Message-Id: <20200630043343.53195-6-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.13.5 In-Reply-To: <20200630043343.53195-1-alexei.starovoitov@gmail.com> References: <20200630043343.53195-1-alexei.starovoitov@gmail.com> Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Alexei Starovoitov Modify few tests to sanity test sleepable bpf functionality. Running 'bench trig-fentry-sleep' vs 'bench trig-fentry' and 'perf report': sleepable with SRCU: 3.86% bench [k] __srcu_read_unlock 3.22% bench [k] __srcu_read_lock 0.92% bench [k] bpf_prog_740d4210cdcd99a3_bench_trigger_fentry_sleep 0.50% bench [k] bpf_trampoline_10297 0.26% bench [k] __bpf_prog_exit_sleepable 0.21% bench [k] __bpf_prog_enter_sleepable sleepable with RCU_TRACE: 0.79% bench [k] bpf_prog_740d4210cdcd99a3_bench_trigger_fentry_sleep 0.72% bench [k] bpf_trampoline_10381 0.31% bench [k] __bpf_prog_exit_sleepable 0.29% bench [k] __bpf_prog_enter_sleepable non-sleepable with RCU: 0.88% bench [k] bpf_prog_740d4210cdcd99a3_bench_trigger_fentry 0.84% bench [k] bpf_trampoline_10297 0.13% bench [k] __bpf_prog_enter 0.12% bench [k] __bpf_prog_exit Signed-off-by: Alexei Starovoitov Acked-by: KP Singh --- tools/testing/selftests/bpf/bench.c | 2 + .../selftests/bpf/benchs/bench_trigger.c | 17 +++++ .../selftests/bpf/prog_tests/test_lsm.c | 9 +++ tools/testing/selftests/bpf/progs/lsm.c | 66 ++++++++++++++++++- .../selftests/bpf/progs/trigger_bench.c | 7 ++ 5 files changed, 99 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c index 944ad4721c83..1a427685a8a8 100644 --- a/tools/testing/selftests/bpf/bench.c +++ b/tools/testing/selftests/bpf/bench.c @@ -317,6 +317,7 @@ extern const struct bench bench_trig_tp; extern const struct bench bench_trig_rawtp; extern const struct bench bench_trig_kprobe; extern const struct bench bench_trig_fentry; +extern const struct bench bench_trig_fentry_sleep; extern const struct bench bench_trig_fmodret; extern const struct bench bench_rb_libbpf; extern const struct bench bench_rb_custom; @@ -338,6 +339,7 @@ static const struct bench *benchs[] = { &bench_trig_rawtp, &bench_trig_kprobe, &bench_trig_fentry, + &bench_trig_fentry_sleep, &bench_trig_fmodret, &bench_rb_libbpf, &bench_rb_custom, diff --git a/tools/testing/selftests/bpf/benchs/bench_trigger.c b/tools/testing/selftests/bpf/benchs/bench_trigger.c index 49c22832f216..2a0b6c9885a4 100644 --- a/tools/testing/selftests/bpf/benchs/bench_trigger.c +++ b/tools/testing/selftests/bpf/benchs/bench_trigger.c @@ -90,6 +90,12 @@ static void trigger_fentry_setup() attach_bpf(ctx.skel->progs.bench_trigger_fentry); } +static void trigger_fentry_sleep_setup() +{ + setup_ctx(); + attach_bpf(ctx.skel->progs.bench_trigger_fentry_sleep); +} + static void trigger_fmodret_setup() { setup_ctx(); @@ -155,6 +161,17 @@ const struct bench bench_trig_fentry = { .report_final = hits_drops_report_final, }; +const struct bench bench_trig_fentry_sleep = { + .name = "trig-fentry-sleep", + .validate = trigger_validate, + .setup = trigger_fentry_sleep_setup, + .producer_thread = trigger_producer, + .consumer_thread = trigger_consumer, + .measure = trigger_measure, + .report_progress = hits_drops_report_progress, + .report_final = hits_drops_report_final, +}; + const struct bench bench_trig_fmodret = { .name = "trig-fmodret", .validate = trigger_validate, diff --git a/tools/testing/selftests/bpf/prog_tests/test_lsm.c b/tools/testing/selftests/bpf/prog_tests/test_lsm.c index b17eb2045c1d..6ab29226c99b 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_lsm.c +++ b/tools/testing/selftests/bpf/prog_tests/test_lsm.c @@ -10,6 +10,7 @@ #include #include #include +#include #include "lsm.skel.h" @@ -55,6 +56,7 @@ void test_test_lsm(void) { struct lsm *skel = NULL; int err, duration = 0; + int buf = 1234; skel = lsm__open_and_load(); if (CHECK(!skel, "skel_load", "lsm skeleton failed\n")) @@ -81,6 +83,13 @@ void test_test_lsm(void) CHECK(skel->bss->mprotect_count != 1, "mprotect_count", "mprotect_count = %d\n", skel->bss->mprotect_count); + syscall(__NR_setdomainname, &buf, -2L); + syscall(__NR_setdomainname, 0, -3L); + syscall(__NR_setdomainname, ~0L, -4L); + + CHECK(skel->bss->copy_test != 3, "copy_test", + "copy_test = %d\n", skel->bss->copy_test); + close_prog: lsm__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/lsm.c b/tools/testing/selftests/bpf/progs/lsm.c index b4598d4bc4f7..49fa6ca99755 100644 --- a/tools/testing/selftests/bpf/progs/lsm.c +++ b/tools/testing/selftests/bpf/progs/lsm.c @@ -9,16 +9,41 @@ #include #include +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u64); +} array SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u64); +} hash SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_LRU_HASH); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u64); +} lru_hash SEC(".maps"); + char _license[] SEC("license") = "GPL"; int monitored_pid = 0; int mprotect_count = 0; int bprm_count = 0; -SEC("lsm/file_mprotect") +SEC("lsm.s/file_mprotect") int BPF_PROG(test_int_hook, struct vm_area_struct *vma, unsigned long reqprot, unsigned long prot, int ret) { + char args[64]; + __u32 key = 0; + __u64 *value; + if (ret != 0) return ret; @@ -28,6 +53,18 @@ int BPF_PROG(test_int_hook, struct vm_area_struct *vma, is_stack = (vma->vm_start <= vma->vm_mm->start_stack && vma->vm_end >= vma->vm_mm->start_stack); + bpf_copy_from_user(args, sizeof(args), (void *)vma->vm_mm->arg_start); + + value = bpf_map_lookup_elem(&array, &key); + if (value) + *value = 0; + value = bpf_map_lookup_elem(&hash, &key); + if (value) + *value = 0; + value = bpf_map_lookup_elem(&lru_hash, &key); + if (value) + *value = 0; + if (is_stack && monitored_pid == pid) { mprotect_count++; ret = -EPERM; @@ -36,7 +73,7 @@ int BPF_PROG(test_int_hook, struct vm_area_struct *vma, return ret; } -SEC("lsm/bprm_committed_creds") +SEC("lsm.s/bprm_committed_creds") int BPF_PROG(test_void_hook, struct linux_binprm *bprm) { __u32 pid = bpf_get_current_pid_tgid() >> 32; @@ -46,3 +83,28 @@ int BPF_PROG(test_void_hook, struct linux_binprm *bprm) return 0; } +SEC("lsm/task_free") /* lsm/ is ok, lsm.s/ fails */ +int BPF_PROG(test_task_free, struct task_struct *task) +{ + return 0; +} + +int copy_test = 0; + +SEC("fentry.s/__x64_sys_setdomainname") +int BPF_PROG(test_sys_setdomainname, struct pt_regs *regs) +{ + void *ptr = (void *)PT_REGS_PARM1(regs); + int len = PT_REGS_PARM2(regs); + int buf = 0; + long ret; + + ret = bpf_copy_from_user(&buf, sizeof(buf), ptr); + if (len == -2 && ret == 0 && buf == 1234) + copy_test++; + if (len == -3 && ret == -EFAULT) + copy_test++; + if (len == -4 && ret == -EFAULT) + copy_test++; + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/trigger_bench.c b/tools/testing/selftests/bpf/progs/trigger_bench.c index 8b36b6640e7e..9a4d09590b3d 100644 --- a/tools/testing/selftests/bpf/progs/trigger_bench.c +++ b/tools/testing/selftests/bpf/progs/trigger_bench.c @@ -39,6 +39,13 @@ int bench_trigger_fentry(void *ctx) return 0; } +SEC("fentry.s/__x64_sys_getpgid") +int bench_trigger_fentry_sleep(void *ctx) +{ + __sync_add_and_fetch(&hits, 1); + return 0; +} + SEC("fmod_ret/__x64_sys_getpgid") int bench_trigger_fmodret(void *ctx) {