From patchwork Tue May 26 16:33:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KP Singh X-Patchwork-Id: 11570829 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id ED1A114B7 for ; Tue, 26 May 2020 16:34:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B534E2073B for ; Tue, 26 May 2020 16:34:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Blo2qDxO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388622AbgEZQdn (ORCPT ); Tue, 26 May 2020 12:33:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729303AbgEZQdl (ORCPT ); Tue, 26 May 2020 12:33:41 -0400 Received: from mail-wr1-x444.google.com (mail-wr1-x444.google.com [IPv6:2a00:1450:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B224C03E96E for ; Tue, 26 May 2020 09:33:41 -0700 (PDT) Received: by mail-wr1-x444.google.com with SMTP id j16so8603034wrb.7 for ; Tue, 26 May 2020 09:33:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=LS90sTALd8NA7/cmV0YDVxNZyjsIa6ptfH5wlHsa5io=; b=Blo2qDxOJplXQ6zslD8qIDWVLd8bWHl2nb2DDJ/wyWbnE2+NKd/CkFu91/gTomj3IK Q87orf5ffNk6LhW+aDLJyIDsT4a7wGM+hpcVLGeQD0bnLwFTAClUSDp3Y0uwdWjMc4iT bk06ozm91Vcti7BAw5q7P+nLPtAGfCTqucU80= 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:mime-version:content-transfer-encoding; bh=LS90sTALd8NA7/cmV0YDVxNZyjsIa6ptfH5wlHsa5io=; b=UtT1Y4kGcLarGnk9c0MVVsVJREuMQc95pQiCYPixWR3aRaLpwKHsOqdFS7cW1Mh7Pp RQGc/+SuOIWc2E8QWwYXjR8AKipmR3XrJ4pnyguC7DDU0o2p2oCQ/J+2KmiMZL1KibhM /l+2fqK06PN6nhZUZ8eSWwDf/5IwoTLSz7Ab71VdNd7uCYKHlP5PeXvIoiPrrQWOw0Zj JO+oR0B6x9iiiyIcKIjUozJyLWf5QFpXOV0BiVBJxFa6+BRVXBLQAxNi51PNEqJkIgb8 uinIKbxH+LTka9nFkTzm6lQGChqz9yt3VAcRkXDYpJ50ZhTkvfbd9xOI+vPEqQ9PCB4Z ccOw== X-Gm-Message-State: AOAM530VoBYcKcTBk2VQbaRYomskVFqjz9T+jCQVpkUw71xcqcMooDO7 rzOG5aQMGRGerVGpDBNaeVhBDg== X-Google-Smtp-Source: ABdhPJxWgfoH9yiX3rP2woDNw4FDLvNtqHCl7MYPyFiZ8pjikrxK8QnY0lsDYDkj0donn2Ue/POSrw== X-Received: by 2002:a5d:484b:: with SMTP id n11mr19279970wrs.356.1590510819423; Tue, 26 May 2020 09:33:39 -0700 (PDT) Received: from kpsingh.zrh.corp.google.com ([81.6.44.51]) by smtp.gmail.com with ESMTPSA id k17sm48654wmj.15.2020.05.26.09.33.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 May 2020 09:33:38 -0700 (PDT) From: KP Singh To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , James Morris , Alexander Viro , Martin KaFai Lau , Florent Revest Subject: [PATCH bpf-next 1/4] bpf: Generalize bpf_sk_storage Date: Tue, 26 May 2020 18:33:33 +0200 Message-Id: <20200526163336.63653-2-kpsingh@chromium.org> X-Mailer: git-send-email 2.27.0.rc0.183.gde8f92d652-goog In-Reply-To: <20200526163336.63653-1-kpsingh@chromium.org> References: <20200526163336.63653-1-kpsingh@chromium.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: KP Singh Refactor the functionality in bpf_sk_storage.c so that concept of storage linked to kernel objects can be extended to other objects like inode, task_struct etc. bpf_sk_storage is updated to be bpf_local_storage with a union that contains a pointer to the owner object. The type of the bpf_local_storage can be determined using the newly added bpf_local_storage_type enum. Each new local storage will still be a separate map and provide its own set of helpers. This allows for future object specific extensions and still share a lot of the underlying implementation. Signed-off-by: KP Singh Reported-by: kbuild test robot --- .../bpf_local_storage.h} | 6 +- include/net/sock.h | 4 +- include/uapi/linux/bpf.h | 13 +- kernel/bpf/Makefile | 4 + .../bpf/bpf_local_storage.c | 593 ++++++++++-------- kernel/bpf/cgroup.c | 2 +- net/bpf/test_run.c | 2 +- net/core/Makefile | 1 - net/core/filter.c | 2 +- net/core/sock.c | 2 +- net/ipv4/bpf_tcp_ca.c | 2 +- net/ipv4/inet_diag.c | 2 +- tools/include/uapi/linux/bpf.h | 13 +- 13 files changed, 365 insertions(+), 281 deletions(-) rename include/{net/bpf_sk_storage.h => linux/bpf_local_storage.h} (93%) rename net/core/bpf_sk_storage.c => kernel/bpf/bpf_local_storage.c (63%) diff --git a/include/net/bpf_sk_storage.h b/include/linux/bpf_local_storage.h similarity index 93% rename from include/net/bpf_sk_storage.h rename to include/linux/bpf_local_storage.h index 5036c94c0503..85524f18cd91 100644 --- a/include/net/bpf_sk_storage.h +++ b/include/linux/bpf_local_storage.h @@ -1,7 +1,7 @@ /* SPDX-License-Identifier: GPL-2.0 */ /* Copyright (c) 2019 Facebook */ -#ifndef _BPF_SK_STORAGE_H -#define _BPF_SK_STORAGE_H +#ifndef _BPF_LOCAL_STORAGE_H +#define _BPF_LOCAL_STORAGE_H struct sock; @@ -47,4 +47,4 @@ static inline int bpf_sk_storage_diag_put(struct bpf_sk_storage_diag *diag, } #endif -#endif /* _BPF_SK_STORAGE_H */ +#endif /* _BPF_LOCAL_STORAGE_H */ diff --git a/include/net/sock.h b/include/net/sock.h index 3e8c6d4b4b59..06b093788eb6 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -245,7 +245,7 @@ struct sock_common { /* public: */ }; -struct bpf_sk_storage; +struct bpf_local_storage; /** * struct sock - network layer representation of sockets @@ -516,7 +516,7 @@ struct sock { void (*sk_destruct)(struct sock *sk); struct sock_reuseport __rcu *sk_reuseport_cb; #ifdef CONFIG_BPF_SYSCALL - struct bpf_sk_storage __rcu *sk_bpf_storage; + struct bpf_local_storage __rcu *sk_bpf_storage; #endif struct rcu_head sk_rcu; }; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 97e1fd19ff58..4a202eea15c0 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2788,10 +2788,10 @@ union bpf_attr { * "type". The bpf-local-storage "type" (i.e. the *map*) is * searched against all bpf-local-storages residing at *sk*. * - * An optional *flags* (**BPF_SK_STORAGE_GET_F_CREATE**) can be + * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be * used such that a new bpf-local-storage will be * created if one does not exist. *value* can be used - * together with **BPF_SK_STORAGE_GET_F_CREATE** to specify + * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify * the initial value of a bpf-local-storage. If *value* is * **NULL**, the new bpf-local-storage will be zero initialized. * Return @@ -3388,11 +3388,16 @@ enum { BPF_F_SYSCTL_BASE_NAME = (1ULL << 0), }; -/* BPF_FUNC_sk_storage_get flags */ +/* BPF_FUNC__storage_get flags */ enum { - BPF_SK_STORAGE_GET_F_CREATE = (1ULL << 0), + BPF_LOCAL_STORAGE_GET_F_CREATE = (1ULL << 0), + /* BPF_SK_STORAGE_GET_F_CREATE is only kept for backward compatibility + * and BPF_LOCAL_STORAGE_GET_F_CREATE must be used instead. + */ + BPF_SK_STORAGE_GET_F_CREATE = BPF_LOCAL_STORAGE_GET_F_CREATE, }; + /* BPF_FUNC_read_branch_records flags. */ enum { BPF_F_GET_BRANCH_RECORDS_SIZE = (1ULL << 0), diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 375b933010dd..0d2c6703e279 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -12,6 +12,10 @@ obj-$(CONFIG_BPF_JIT) += dispatcher.o ifeq ($(CONFIG_NET),y) obj-$(CONFIG_BPF_SYSCALL) += devmap.o obj-$(CONFIG_BPF_SYSCALL) += cpumap.o +obj-$(CONFIG_BPF_SYSCALL) += bpf_local_storage.o +ifeq ($(CONFIG_XDP_SOCKETS),y) +obj-$(CONFIG_BPF_SYSCALL) += xskmap.o +endif obj-$(CONFIG_BPF_SYSCALL) += offload.o endif ifeq ($(CONFIG_PERF_EVENTS),y) diff --git a/net/core/bpf_sk_storage.c b/kernel/bpf/bpf_local_storage.c similarity index 63% rename from net/core/bpf_sk_storage.c rename to kernel/bpf/bpf_local_storage.c index d2c4d16dadba..0a1caac2f5f7 100644 --- a/net/core/bpf_sk_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -6,14 +6,14 @@ #include #include #include -#include +#include #include #include #include static atomic_t cache_idx; -#define SK_STORAGE_CREATE_FLAG_MASK \ +#define LOCAL_STORAGE_CREATE_FLAG_MASK \ (BPF_F_NO_PREALLOC | BPF_F_CLONE) struct bucket { @@ -21,11 +21,15 @@ struct bucket { raw_spinlock_t lock; }; -/* Thp map is not the primary owner of a bpf_sk_storage_elem. +enum bpf_local_storage_type { + BPF_LOCAL_STORAGE_SK, +}; + +/* Thp map is not the primary owner of a bpf_local_storage_elem. * Instead, the sk->sk_bpf_storage is. * - * The map (bpf_sk_storage_map) is for two purposes - * 1. Define the size of the "sk local storage". It is + * The map (bpf_local_storage_map) is for two purposes + * 1. Define the size of the "local storage". It is * the map's value_size. * * 2. Maintain a list to keep track of all elems such @@ -34,12 +38,12 @@ struct bucket { * When a bpf local storage is being looked up for a * particular sk, the "bpf_map" pointer is actually used * as the "key" to search in the list of elem in - * sk->sk_bpf_storage. + * the respective bpf_local_storage owned by the object. * - * Hence, consider sk->sk_bpf_storage is the mini-map - * with the "bpf_map" pointer as the searching key. + * e.g. sk->sk_bpf_storage is the mini-map with the "bpf_map" pointer + * as the searching key. */ -struct bpf_sk_storage_map { +struct bpf_local_storage_map { struct bpf_map map; /* Lookup elem does not require accessing the map. * @@ -53,46 +57,51 @@ struct bpf_sk_storage_map { u16 cache_idx; }; -struct bpf_sk_storage_data { +struct bpf_local_storage_data { /* smap is used as the searching key when looking up * from sk->sk_bpf_storage. * * Put it in the same cacheline as the data to minimize * the number of cachelines access during the cache hit case. */ - struct bpf_sk_storage_map __rcu *smap; + struct bpf_local_storage_map __rcu *smap; u8 data[] __aligned(8); }; -/* Linked to bpf_sk_storage and bpf_sk_storage_map */ -struct bpf_sk_storage_elem { - struct hlist_node map_node; /* Linked to bpf_sk_storage_map */ - struct hlist_node snode; /* Linked to bpf_sk_storage */ - struct bpf_sk_storage __rcu *sk_storage; +/* Linked to bpf_local_storage and bpf_local_storage_map */ +struct bpf_local_storage_elem { + struct hlist_node map_node; /* Linked to bpf_local_storage_map */ + struct hlist_node snode; /* Linked to bpf_local_storage */ + struct bpf_local_storage __rcu *local_storage; struct rcu_head rcu; /* 8 bytes hole */ /* The data is stored in aother cacheline to minimize * the number of cachelines access during a cache hit. */ - struct bpf_sk_storage_data sdata ____cacheline_aligned; + struct bpf_local_storage_data sdata ____cacheline_aligned; }; -#define SELEM(_SDATA) container_of((_SDATA), struct bpf_sk_storage_elem, sdata) +#define SELEM(_SDATA) \ + container_of((_SDATA), struct bpf_local_storage_elem, sdata) #define SDATA(_SELEM) (&(_SELEM)->sdata) -#define BPF_SK_STORAGE_CACHE_SIZE 16 - -struct bpf_sk_storage { - struct bpf_sk_storage_data __rcu *cache[BPF_SK_STORAGE_CACHE_SIZE]; - struct hlist_head list; /* List of bpf_sk_storage_elem */ - struct sock *sk; /* The sk that owns the the above "list" of - * bpf_sk_storage_elem. - */ +#define BPF_STORAGE_CACHE_SIZE 16 + +struct bpf_local_storage { + struct bpf_local_storage_data __rcu *cache[BPF_STORAGE_CACHE_SIZE]; + struct hlist_head list; /* List of bpf_local_storage_elem */ + /* The object that owns the the above "list" of + * bpf_local_storage_elem + */ + union { + struct sock *sk; + }; struct rcu_head rcu; raw_spinlock_t lock; /* Protect adding/removing from the "list" */ + enum bpf_local_storage_type stype; }; -static struct bucket *select_bucket(struct bpf_sk_storage_map *smap, - struct bpf_sk_storage_elem *selem) +static struct bucket *select_bucket(struct bpf_local_storage_map *smap, + struct bpf_local_storage_elem *selem) { return &smap->buckets[hash_ptr(selem, smap->bucket_log)]; } @@ -109,24 +118,20 @@ static int omem_charge(struct sock *sk, unsigned int size) return -ENOMEM; } -static bool selem_linked_to_sk(const struct bpf_sk_storage_elem *selem) +static bool selem_linked_to_node(const struct bpf_local_storage_elem *selem) { return !hlist_unhashed(&selem->snode); } -static bool selem_linked_to_map(const struct bpf_sk_storage_elem *selem) +static bool selem_linked_to_map(const struct bpf_local_storage_elem *selem) { return !hlist_unhashed(&selem->map_node); } -static struct bpf_sk_storage_elem *selem_alloc(struct bpf_sk_storage_map *smap, - struct sock *sk, void *value, - bool charge_omem) +static struct bpf_local_storage_elem *selem_alloc( + struct bpf_local_storage_map *smap, void *value) { - struct bpf_sk_storage_elem *selem; - - if (charge_omem && omem_charge(sk, smap->elem_size)) - return NULL; + struct bpf_local_storage_elem *selem; selem = kzalloc(smap->elem_size, GFP_ATOMIC | __GFP_NOWARN); if (selem) { @@ -135,94 +140,103 @@ static struct bpf_sk_storage_elem *selem_alloc(struct bpf_sk_storage_map *smap, return selem; } + return NULL; +} + +static struct bpf_local_storage_elem *sk_selem_alloc( + struct bpf_local_storage_map *smap, struct sock *sk, void *value, + bool charge_omem) +{ + struct bpf_local_storage_elem *selem; + + if (charge_omem && omem_charge(sk, smap->elem_size)) + return NULL; + + selem = selem_alloc(smap, value); + if (selem) + return selem; + if (charge_omem) atomic_sub(smap->elem_size, &sk->sk_omem_alloc); return NULL; } -/* sk_storage->lock must be held and selem->sk_storage == sk_storage. +static void __unlink_local_storage(struct bpf_local_storage *local_storage, + bool uncharge_omem) +{ + struct sock *sk; + + switch (local_storage->stype) { + case BPF_LOCAL_STORAGE_SK: + sk = local_storage->sk; + if (uncharge_omem) + atomic_sub(sizeof(struct bpf_local_storage), + &sk->sk_omem_alloc); + + /* After this RCU_INIT, sk may be freed and cannot be used */ + RCU_INIT_POINTER(sk->sk_bpf_storage, NULL); + local_storage->sk = NULL; + break; + } +} + +/* local_storage->lock must be held and selem->local_storage == local_storage. * The caller must ensure selem->smap is still valid to be * dereferenced for its smap->elem_size and smap->cache_idx. + * + * uncharge_omem is only relevant when: + * + * local_storage->stype == BPF_LOCAL_STORAGE_SK + * */ -static bool __selem_unlink_sk(struct bpf_sk_storage *sk_storage, - struct bpf_sk_storage_elem *selem, - bool uncharge_omem) +static bool __selem_unlink(struct bpf_local_storage *local_storage, + struct bpf_local_storage_elem *selem, + bool uncharge_omem) { - struct bpf_sk_storage_map *smap; - bool free_sk_storage; - struct sock *sk; + struct bpf_local_storage_map *smap; + bool free_local_storage; smap = rcu_dereference(SDATA(selem)->smap); - sk = sk_storage->sk; - - /* All uncharging on sk->sk_omem_alloc must be done first. - * sk may be freed once the last selem is unlinked from sk_storage. + free_local_storage = hlist_is_singular_node(&selem->snode, + &local_storage->list); + + /* local_storage is not freed now. local_storage->lock is + * still held and raw_spin_unlock_bh(&local_storage->lock) + * will be done by the caller. + * Although the unlock will be done under + * rcu_read_lock(), it is more intutivie to + * read if kfree_rcu(local_storage, rcu) is done + * after the raw_spin_unlock_bh(&local_storage->lock). + * + * Hence, a "bool free_local_storage" is returned + * to the caller which then calls the kfree_rcu() + * after unlock. */ - if (uncharge_omem) - atomic_sub(smap->elem_size, &sk->sk_omem_alloc); + if (free_local_storage) + __unlink_local_storage(local_storage, uncharge_omem); - free_sk_storage = hlist_is_singular_node(&selem->snode, - &sk_storage->list); - if (free_sk_storage) { - atomic_sub(sizeof(struct bpf_sk_storage), &sk->sk_omem_alloc); - sk_storage->sk = NULL; - /* After this RCU_INIT, sk may be freed and cannot be used */ - RCU_INIT_POINTER(sk->sk_bpf_storage, NULL); - /* sk_storage is not freed now. sk_storage->lock is - * still held and raw_spin_unlock_bh(&sk_storage->lock) - * will be done by the caller. - * - * Although the unlock will be done under - * rcu_read_lock(), it is more intutivie to - * read if kfree_rcu(sk_storage, rcu) is done - * after the raw_spin_unlock_bh(&sk_storage->lock). - * - * Hence, a "bool free_sk_storage" is returned - * to the caller which then calls the kfree_rcu() - * after unlock. - */ - } hlist_del_init_rcu(&selem->snode); - if (rcu_access_pointer(sk_storage->cache[smap->cache_idx]) == + if (rcu_access_pointer(local_storage->cache[smap->cache_idx]) == SDATA(selem)) - RCU_INIT_POINTER(sk_storage->cache[smap->cache_idx], NULL); + RCU_INIT_POINTER(local_storage->cache[smap->cache_idx], NULL); kfree_rcu(selem, rcu); - return free_sk_storage; + return free_local_storage; } -static void selem_unlink_sk(struct bpf_sk_storage_elem *selem) +static void __selem_link(struct bpf_local_storage *local_storage, + struct bpf_local_storage_elem *selem) { - struct bpf_sk_storage *sk_storage; - bool free_sk_storage = false; - - if (unlikely(!selem_linked_to_sk(selem))) - /* selem has already been unlinked from sk */ - return; - - sk_storage = rcu_dereference(selem->sk_storage); - raw_spin_lock_bh(&sk_storage->lock); - if (likely(selem_linked_to_sk(selem))) - free_sk_storage = __selem_unlink_sk(sk_storage, selem, true); - raw_spin_unlock_bh(&sk_storage->lock); - - if (free_sk_storage) - kfree_rcu(sk_storage, rcu); -} - -static void __selem_link_sk(struct bpf_sk_storage *sk_storage, - struct bpf_sk_storage_elem *selem) -{ - RCU_INIT_POINTER(selem->sk_storage, sk_storage); - hlist_add_head(&selem->snode, &sk_storage->list); + RCU_INIT_POINTER(selem->local_storage, local_storage); + hlist_add_head(&selem->snode, &local_storage->list); } -static void selem_unlink_map(struct bpf_sk_storage_elem *selem) +static void selem_unlink_map(struct bpf_local_storage_elem *selem) { - struct bpf_sk_storage_map *smap; + struct bpf_local_storage_map *smap; struct bucket *b; if (unlikely(!selem_linked_to_map(selem))) @@ -237,8 +251,8 @@ static void selem_unlink_map(struct bpf_sk_storage_elem *selem) raw_spin_unlock_bh(&b->lock); } -static void selem_link_map(struct bpf_sk_storage_map *smap, - struct bpf_sk_storage_elem *selem) +static void selem_link_map(struct bpf_local_storage_map *smap, + struct bpf_local_storage_elem *selem) { struct bucket *b = select_bucket(smap, selem); @@ -248,31 +262,46 @@ static void selem_link_map(struct bpf_sk_storage_map *smap, raw_spin_unlock_bh(&b->lock); } -static void selem_unlink(struct bpf_sk_storage_elem *selem) +static void selem_unlink(struct bpf_local_storage_elem *selem) { - /* Always unlink from map before unlinking from sk_storage + struct bpf_local_storage *local_storage; + bool free_local_storage = false; + + /* Always unlink from map before unlinking from local_storage * because selem will be freed after successfully unlinked from - * the sk_storage. + * the local_storage. */ selem_unlink_map(selem); - selem_unlink_sk(selem); + + if (unlikely(!selem_linked_to_node(selem))) + /* selem has already been unlinked from its owner */ + return; + + local_storage = rcu_dereference(selem->local_storage); + raw_spin_lock_bh(&local_storage->lock); + if (likely(selem_linked_to_node(selem))) + free_local_storage = __selem_unlink(local_storage, selem, true); + raw_spin_unlock_bh(&local_storage->lock); + + if (free_local_storage) + kfree_rcu(local_storage, rcu); } -static struct bpf_sk_storage_data * -__sk_storage_lookup(struct bpf_sk_storage *sk_storage, - struct bpf_sk_storage_map *smap, +static struct bpf_local_storage_data * +__local_storage_lookup(struct bpf_local_storage *local_storage, + struct bpf_local_storage_map *smap, bool cacheit_lockit) { - struct bpf_sk_storage_data *sdata; - struct bpf_sk_storage_elem *selem; + struct bpf_local_storage_data *sdata; + struct bpf_local_storage_elem *selem; /* Fast path (cache hit) */ - sdata = rcu_dereference(sk_storage->cache[smap->cache_idx]); + sdata = rcu_dereference(local_storage->cache[smap->cache_idx]); if (sdata && rcu_access_pointer(sdata->smap) == smap) return sdata; /* Slow path (cache miss) */ - hlist_for_each_entry_rcu(selem, &sk_storage->list, snode) + hlist_for_each_entry_rcu(selem, &local_storage->list, snode) if (rcu_access_pointer(SDATA(selem)->smap) == smap) break; @@ -284,33 +313,33 @@ __sk_storage_lookup(struct bpf_sk_storage *sk_storage, /* spinlock is needed to avoid racing with the * parallel delete. Otherwise, publishing an already * deleted sdata to the cache will become a use-after-free - * problem in the next __sk_storage_lookup(). + * problem in the next __local_storage_lookup(). */ - raw_spin_lock_bh(&sk_storage->lock); - if (selem_linked_to_sk(selem)) - rcu_assign_pointer(sk_storage->cache[smap->cache_idx], - sdata); - raw_spin_unlock_bh(&sk_storage->lock); + raw_spin_lock_bh(&local_storage->lock); + if (selem_linked_to_node(selem)) + rcu_assign_pointer( + local_storage->cache[smap->cache_idx], sdata); + raw_spin_unlock_bh(&local_storage->lock); } return sdata; } -static struct bpf_sk_storage_data * +static struct bpf_local_storage_data * sk_storage_lookup(struct sock *sk, struct bpf_map *map, bool cacheit_lockit) { - struct bpf_sk_storage *sk_storage; - struct bpf_sk_storage_map *smap; + struct bpf_local_storage *sk_storage; + struct bpf_local_storage_map *smap; sk_storage = rcu_dereference(sk->sk_bpf_storage); if (!sk_storage) return NULL; - smap = (struct bpf_sk_storage_map *)map; - return __sk_storage_lookup(sk_storage, smap, cacheit_lockit); + smap = (struct bpf_local_storage_map *)map; + return __local_storage_lookup(sk_storage, smap, cacheit_lockit); } -static int check_flags(const struct bpf_sk_storage_data *old_sdata, +static int check_flags(const struct bpf_local_storage_data *old_sdata, u64 map_flags) { if (old_sdata && (map_flags & ~BPF_F_LOCK) == BPF_NOEXIST) @@ -324,93 +353,129 @@ static int check_flags(const struct bpf_sk_storage_data *old_sdata, return 0; } -static int sk_storage_alloc(struct sock *sk, - struct bpf_sk_storage_map *smap, - struct bpf_sk_storage_elem *first_selem) +static struct bpf_local_storage * +bpf_local_storage_alloc(struct bpf_local_storage_map *smap) { - struct bpf_sk_storage *prev_sk_storage, *sk_storage; - int err; + struct bpf_local_storage *storage; - err = omem_charge(sk, sizeof(*sk_storage)); - if (err) - return err; + storage = kzalloc(sizeof(*storage), GFP_ATOMIC | __GFP_NOWARN); + if (!storage) + return NULL; - sk_storage = kzalloc(sizeof(*sk_storage), GFP_ATOMIC | __GFP_NOWARN); - if (!sk_storage) { - err = -ENOMEM; - goto uncharge; - } - INIT_HLIST_HEAD(&sk_storage->list); - raw_spin_lock_init(&sk_storage->lock); - sk_storage->sk = sk; + INIT_HLIST_HEAD(&storage->list); + raw_spin_lock_init(&storage->lock); + return storage; +} - __selem_link_sk(sk_storage, first_selem); - selem_link_map(smap, first_selem); - /* Publish sk_storage to sk. sk->sk_lock cannot be acquired. - * Hence, atomic ops is used to set sk->sk_bpf_storage - * from NULL to the newly allocated sk_storage ptr. - * - * From now on, the sk->sk_bpf_storage pointer is protected - * by the sk_storage->lock. Hence, when freeing - * the sk->sk_bpf_storage, the sk_storage->lock must - * be held before setting sk->sk_bpf_storage to NULL. - */ - prev_sk_storage = cmpxchg((struct bpf_sk_storage **)&sk->sk_bpf_storage, - NULL, sk_storage); - if (unlikely(prev_sk_storage)) { - selem_unlink_map(first_selem); - err = -EAGAIN; - goto uncharge; +/* Publish local_storage to the address. This is used because we are already + * in a region where we cannot grab a lock on the object owning the storage ( + * (e.g sk->sk_lock). Hence, atomic ops is used. + * + * From now on, the addr pointer is protected + * by the local_storage->lock. Hence, upon freeing, + * the local_storage->lock must be held before unlinking the storage from the + * owner. + */ +static int publish_local_storage(struct bpf_local_storage_elem *first_selem, + struct bpf_local_storage **addr, + struct bpf_local_storage *curr) +{ + struct bpf_local_storage *prev; + prev = cmpxchg(addr, NULL, curr); + if (unlikely(prev)) { /* Note that even first_selem was linked to smap's * bucket->list, first_selem can be freed immediately * (instead of kfree_rcu) because - * bpf_sk_storage_map_free() does a + * bpf_local_storage_map_free() does a * synchronize_rcu() before walking the bucket->list. * Hence, no one is accessing selem from the * bucket->list under rcu_read_lock(). */ + selem_unlink_map(first_selem); + return -EAGAIN; } return 0; +} + +static int sk_storage_alloc(struct sock *sk, + struct bpf_local_storage_map *smap, + struct bpf_local_storage_elem *first_selem) +{ + struct bpf_local_storage *curr; + int err; + + err = omem_charge(sk, sizeof(*curr)); + if (err) + return err; + + curr = bpf_local_storage_alloc(smap); + if (!curr) { + err = -ENOMEM; + goto uncharge; + } + + curr->sk = sk; + curr->stype = BPF_LOCAL_STORAGE_SK; + + __selem_link(curr, first_selem); + selem_link_map(smap, first_selem); + + err = publish_local_storage(first_selem, + (struct bpf_local_storage **)&sk->sk_bpf_storage, curr); + if (err) + goto uncharge; + + return 0; uncharge: - kfree(sk_storage); - atomic_sub(sizeof(*sk_storage), &sk->sk_omem_alloc); + kfree(curr); + atomic_sub(sizeof(*curr), &sk->sk_omem_alloc); return err; } +static int check_update_flags(struct bpf_map *map, u64 map_flags) +{ + /* BPF_EXIST and BPF_NOEXIST cannot be both set */ + if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST) || + /* BPF_F_LOCK can only be used in a value with spin_lock */ + unlikely((map_flags & BPF_F_LOCK) && !map_value_has_spin_lock(map))) + return -EINVAL; + + return 0; +} + /* sk cannot be going away because it is linking new elem * to sk->sk_bpf_storage. (i.e. sk->sk_refcnt cannot be 0). * Otherwise, it will become a leak (and other memory issues * during map destruction). */ -static struct bpf_sk_storage_data *sk_storage_update(struct sock *sk, +static struct bpf_local_storage_data *sk_storage_update(struct sock *sk, struct bpf_map *map, void *value, u64 map_flags) { - struct bpf_sk_storage_data *old_sdata = NULL; - struct bpf_sk_storage_elem *selem; - struct bpf_sk_storage *sk_storage; - struct bpf_sk_storage_map *smap; + struct bpf_local_storage_data *old_sdata = NULL; + struct bpf_local_storage_elem *selem; + struct bpf_local_storage *local_storage; + struct bpf_local_storage_map *smap; int err; - /* BPF_EXIST and BPF_NOEXIST cannot be both set */ - if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST) || - /* BPF_F_LOCK can only be used in a value with spin_lock */ - unlikely((map_flags & BPF_F_LOCK) && !map_value_has_spin_lock(map))) - return ERR_PTR(-EINVAL); + err = check_update_flags(map, map_flags); + if (err) + return ERR_PTR(err); - smap = (struct bpf_sk_storage_map *)map; - sk_storage = rcu_dereference(sk->sk_bpf_storage); - if (!sk_storage || hlist_empty(&sk_storage->list)) { + smap = (struct bpf_local_storage_map *)map; + + local_storage = rcu_dereference(sk->sk_bpf_storage); + if (!local_storage || hlist_empty(&local_storage->list)) { /* Very first elem for this sk */ err = check_flags(NULL, map_flags); if (err) return ERR_PTR(err); - selem = selem_alloc(smap, sk, value, true); + selem = sk_selem_alloc(smap, sk, value, true); if (!selem) return ERR_PTR(-ENOMEM); @@ -426,25 +491,26 @@ static struct bpf_sk_storage_data *sk_storage_update(struct sock *sk, if ((map_flags & BPF_F_LOCK) && !(map_flags & BPF_NOEXIST)) { /* Hoping to find an old_sdata to do inline update - * such that it can avoid taking the sk_storage->lock + * such that it can avoid taking the local_storage->lock * and changing the lists. */ - old_sdata = __sk_storage_lookup(sk_storage, smap, false); + old_sdata = __local_storage_lookup(local_storage, smap, false); err = check_flags(old_sdata, map_flags); if (err) return ERR_PTR(err); - if (old_sdata && selem_linked_to_sk(SELEM(old_sdata))) { + + if (old_sdata && selem_linked_to_node(SELEM(old_sdata))) { copy_map_value_locked(map, old_sdata->data, value, false); return old_sdata; } } - raw_spin_lock_bh(&sk_storage->lock); + raw_spin_lock_bh(&local_storage->lock); - /* Recheck sk_storage->list under sk_storage->lock */ - if (unlikely(hlist_empty(&sk_storage->list))) { - /* A parallel del is happening and sk_storage is going + /* Recheck local_storage->list under local_storage->lock */ + if (unlikely(hlist_empty(&local_storage->list))) { + /* A parallel del is happening and local_storage is going * away. It has just been checked before, so very * unlikely. Return instead of retry to keep things * simple. @@ -453,7 +519,7 @@ static struct bpf_sk_storage_data *sk_storage_update(struct sock *sk, goto unlock_err; } - old_sdata = __sk_storage_lookup(sk_storage, smap, false); + old_sdata = __local_storage_lookup(local_storage, smap, false); err = check_flags(old_sdata, map_flags); if (err) goto unlock_err; @@ -464,15 +530,15 @@ static struct bpf_sk_storage_data *sk_storage_update(struct sock *sk, goto unlock; } - /* sk_storage->lock is held. Hence, we are sure + /* local_storage->lock is held. Hence, we are sure * we can unlink and uncharge the old_sdata successfully * later. Hence, instead of charging the new selem now * and then uncharge the old selem later (which may cause * a potential but unnecessary charge failure), avoid taking * a charge at all here (the "!old_sdata" check) and the - * old_sdata will not be uncharged later during __selem_unlink_sk(). + * old_sdata will not be uncharged later during __selem_unlink(). */ - selem = selem_alloc(smap, sk, value, !old_sdata); + selem = sk_selem_alloc(smap, sk, value, !old_sdata); if (!selem) { err = -ENOMEM; goto unlock_err; @@ -481,27 +547,27 @@ static struct bpf_sk_storage_data *sk_storage_update(struct sock *sk, /* First, link the new selem to the map */ selem_link_map(smap, selem); - /* Second, link (and publish) the new selem to sk_storage */ - __selem_link_sk(sk_storage, selem); + /* Second, link (and publish) the new selem to local_storage */ + __selem_link(local_storage, selem); /* Third, remove old selem, SELEM(old_sdata) */ if (old_sdata) { selem_unlink_map(SELEM(old_sdata)); - __selem_unlink_sk(sk_storage, SELEM(old_sdata), false); + __selem_unlink(local_storage, SELEM(old_sdata), false); } unlock: - raw_spin_unlock_bh(&sk_storage->lock); + raw_spin_unlock_bh(&local_storage->lock); return SDATA(selem); unlock_err: - raw_spin_unlock_bh(&sk_storage->lock); + raw_spin_unlock_bh(&local_storage->lock); return ERR_PTR(err); } static int sk_storage_delete(struct sock *sk, struct bpf_map *map) { - struct bpf_sk_storage_data *sdata; + struct bpf_local_storage_data *sdata; sdata = sk_storage_lookup(sk, map, false); if (!sdata) @@ -515,8 +581,8 @@ static int sk_storage_delete(struct sock *sk, struct bpf_map *map) /* Called by __sk_destruct() & bpf_sk_storage_clone() */ void bpf_sk_storage_free(struct sock *sk) { - struct bpf_sk_storage_elem *selem; - struct bpf_sk_storage *sk_storage; + struct bpf_local_storage_elem *selem; + struct bpf_local_storage *sk_storage; bool free_sk_storage = false; struct hlist_node *n; @@ -530,9 +596,9 @@ void bpf_sk_storage_free(struct sock *sk) /* Netiher the bpf_prog nor the bpf-map's syscall * could be modifying the sk_storage->list now. * Thus, no elem can be added-to or deleted-from the - * sk_storage->list by the bpf_prog or by the bpf-map's syscall. + * local_storage->list by the bpf_prog or by the bpf-map's syscall. * - * It is racing with bpf_sk_storage_map_free() alone + * It is racing with bpf_local_storage_map_free() alone * when unlinking elem from the sk_storage->list and * the map's bucket->list. */ @@ -542,7 +608,7 @@ void bpf_sk_storage_free(struct sock *sk) * sk_storage. */ selem_unlink_map(selem); - free_sk_storage = __selem_unlink_sk(sk_storage, selem, true); + free_sk_storage = __selem_unlink(sk_storage, selem, true); } raw_spin_unlock_bh(&sk_storage->lock); rcu_read_unlock(); @@ -551,14 +617,14 @@ void bpf_sk_storage_free(struct sock *sk) kfree_rcu(sk_storage, rcu); } -static void bpf_sk_storage_map_free(struct bpf_map *map) +static void bpf_local_storage_map_free(struct bpf_map *map) { - struct bpf_sk_storage_elem *selem; - struct bpf_sk_storage_map *smap; + struct bpf_local_storage_elem *selem; + struct bpf_local_storage_map *smap; struct bucket *b; unsigned int i; - smap = (struct bpf_sk_storage_map *)map; + smap = (struct bpf_local_storage_map *)map; /* Note that this map might be concurrently cloned from * bpf_sk_storage_clone. Wait for any existing bpf_sk_storage_clone @@ -569,11 +635,11 @@ static void bpf_sk_storage_map_free(struct bpf_map *map) /* bpf prog and the userspace can no longer access this map * now. No new selem (of this map) can be added - * to the sk->sk_bpf_storage or to the map bucket's list. + * to the bpf_local_storage or to the map bucket's list. * * The elem of this map can be cleaned up here - * or - * by bpf_sk_storage_free() during __sk_destruct(). + * or by bpf_local_storage_free() during the destruction of the + * owner object. eg. __sk_destruct. */ for (i = 0; i < (1U << smap->bucket_log); i++) { b = &smap->buckets[i]; @@ -581,7 +647,7 @@ static void bpf_sk_storage_map_free(struct bpf_map *map) rcu_read_lock(); /* No one is adding to b->list now */ while ((selem = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(&b->list)), - struct bpf_sk_storage_elem, + struct bpf_local_storage_elem, map_node))) { selem_unlink(selem); cond_resched_rcu(); @@ -589,17 +655,17 @@ static void bpf_sk_storage_map_free(struct bpf_map *map) rcu_read_unlock(); } - /* bpf_sk_storage_free() may still need to access the map. - * e.g. bpf_sk_storage_free() has unlinked selem from the map + /* bpf_local_storage_free() may still need to access the map. + * e.g. bpf_local_storage_free() has unlinked selem from the map * which then made the above while((selem = ...)) loop * exited immediately. * - * However, the bpf_sk_storage_free() still needs to access + * However, the bpf_local_storage_free() still needs to access * the smap->elem_size to do the uncharging in - * __selem_unlink_sk(). + * __selem_unlink(). * * Hence, wait another rcu grace period for the - * bpf_sk_storage_free() to finish. + * bpf_local_storage_free() to finish. */ synchronize_rcu(); @@ -612,12 +678,13 @@ static void bpf_sk_storage_map_free(struct bpf_map *map) */ #define MAX_VALUE_SIZE \ min_t(u32, \ - (KMALLOC_MAX_SIZE - MAX_BPF_STACK - sizeof(struct bpf_sk_storage_elem)), \ - (U16_MAX - sizeof(struct bpf_sk_storage_elem))) + (KMALLOC_MAX_SIZE - MAX_BPF_STACK - \ + sizeof(struct bpf_local_storage_elem)), \ + (U16_MAX - sizeof(struct bpf_local_storage_elem))) -static int bpf_sk_storage_map_alloc_check(union bpf_attr *attr) +static int bpf_local_storage_map_alloc_check(union bpf_attr *attr) { - if (attr->map_flags & ~SK_STORAGE_CREATE_FLAG_MASK || + if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK || !(attr->map_flags & BPF_F_NO_PREALLOC) || attr->max_entries || attr->key_size != sizeof(int) || !attr->value_size || @@ -634,9 +701,11 @@ static int bpf_sk_storage_map_alloc_check(union bpf_attr *attr) return 0; } -static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr) + +static struct bpf_map * +bpf_local_storage_map_alloc(union bpf_attr *attr) { - struct bpf_sk_storage_map *smap; + struct bpf_local_storage_map *smap; unsigned int i; u32 nbuckets; u64 cost; @@ -672,9 +741,10 @@ static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr) raw_spin_lock_init(&smap->buckets[i].lock); } - smap->elem_size = sizeof(struct bpf_sk_storage_elem) + attr->value_size; + smap->elem_size = + sizeof(struct bpf_local_storage_elem) + attr->value_size; smap->cache_idx = (unsigned int)atomic_inc_return(&cache_idx) % - BPF_SK_STORAGE_CACHE_SIZE; + BPF_STORAGE_CACHE_SIZE; return &smap->map; } @@ -685,7 +755,7 @@ static int notsupp_get_next_key(struct bpf_map *map, void *key, return -ENOTSUPP; } -static int bpf_sk_storage_map_check_btf(const struct bpf_map *map, +static int bpf_local_storage_map_check_btf(const struct bpf_map *map, const struct btf *btf, const struct btf_type *key_type, const struct btf_type *value_type) @@ -702,11 +772,11 @@ static int bpf_sk_storage_map_check_btf(const struct bpf_map *map, return 0; } -static void *bpf_fd_sk_storage_lookup_elem(struct bpf_map *map, void *key) +static void *bpf_sk_storage_lookup_elem(struct bpf_map *map, void *key) { - struct bpf_sk_storage_data *sdata; + struct bpf_local_storage_data *sdata; struct socket *sock; - int fd, err; + int fd, err = -EINVAL; fd = *(int *)key; sock = sockfd_lookup(fd, &err); @@ -719,17 +789,18 @@ static void *bpf_fd_sk_storage_lookup_elem(struct bpf_map *map, void *key) return ERR_PTR(err); } -static int bpf_fd_sk_storage_update_elem(struct bpf_map *map, void *key, +static int bpf_sk_storage_update_elem(struct bpf_map *map, void *key, void *value, u64 map_flags) { - struct bpf_sk_storage_data *sdata; + struct bpf_local_storage_data *sdata; struct socket *sock; - int fd, err; + int fd, err = -EINVAL; fd = *(int *)key; sock = sockfd_lookup(fd, &err); if (sock) { - sdata = sk_storage_update(sock->sk, map, value, map_flags); + sdata = sk_storage_update(sock->sk, map, value, + map_flags); sockfd_put(sock); return PTR_ERR_OR_ZERO(sdata); } @@ -737,30 +808,29 @@ static int bpf_fd_sk_storage_update_elem(struct bpf_map *map, void *key, return err; } -static int bpf_fd_sk_storage_delete_elem(struct bpf_map *map, void *key) +static int bpf_sk_storage_delete_elem(struct bpf_map *map, void *key) { struct socket *sock; - int fd, err; + int fd, err = -EINVAL; fd = *(int *)key; sock = sockfd_lookup(fd, &err); if (sock) { err = sk_storage_delete(sock->sk, map); sockfd_put(sock); - return err; } return err; } -static struct bpf_sk_storage_elem * +static struct bpf_local_storage_elem * bpf_sk_storage_clone_elem(struct sock *newsk, - struct bpf_sk_storage_map *smap, - struct bpf_sk_storage_elem *selem) + struct bpf_local_storage_map *smap, + struct bpf_local_storage_elem *selem) { - struct bpf_sk_storage_elem *copy_selem; + struct bpf_local_storage_elem *copy_selem; - copy_selem = selem_alloc(smap, newsk, NULL, true); + copy_selem = sk_selem_alloc(smap, newsk, NULL, true); if (!copy_selem) return NULL; @@ -776,9 +846,9 @@ bpf_sk_storage_clone_elem(struct sock *newsk, int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) { - struct bpf_sk_storage *new_sk_storage = NULL; - struct bpf_sk_storage *sk_storage; - struct bpf_sk_storage_elem *selem; + struct bpf_local_storage *new_sk_storage = NULL; + struct bpf_local_storage *sk_storage; + struct bpf_local_storage_elem *selem; int ret = 0; RCU_INIT_POINTER(newsk->sk_bpf_storage, NULL); @@ -790,8 +860,8 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) goto out; hlist_for_each_entry_rcu(selem, &sk_storage->list, snode) { - struct bpf_sk_storage_elem *copy_selem; - struct bpf_sk_storage_map *smap; + struct bpf_local_storage_elem *copy_selem; + struct bpf_local_storage_map *smap; struct bpf_map *map; smap = rcu_dereference(SDATA(selem)->smap); @@ -799,7 +869,7 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) continue; /* Note that for lockless listeners adding new element - * here can race with cleanup in bpf_sk_storage_map_free. + * here can race with cleanup in bpf_local_storage_map_free. * Try to grab map refcnt to make sure that it's still * alive and prevent concurrent removal. */ @@ -816,7 +886,7 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) if (new_sk_storage) { selem_link_map(smap, copy_selem); - __selem_link_sk(new_sk_storage, copy_selem); + __selem_link(new_sk_storage, copy_selem); } else { ret = sk_storage_alloc(newsk, smap, copy_selem); if (ret) { @@ -827,7 +897,8 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) goto out; } - new_sk_storage = rcu_dereference(copy_selem->sk_storage); + new_sk_storage = + rcu_dereference(copy_selem->local_storage); } bpf_map_put(map); } @@ -836,7 +907,7 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) rcu_read_unlock(); /* In case of an error, don't free anything explicitly here, the - * caller is responsible to call bpf_sk_storage_free. + * caller is responsible to call bpf_local_storage_free. */ return ret; @@ -845,7 +916,7 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk, void *, value, u64, flags) { - struct bpf_sk_storage_data *sdata; + struct bpf_local_storage_data *sdata; if (flags > BPF_SK_STORAGE_GET_F_CREATE) return (unsigned long)NULL; @@ -854,7 +925,7 @@ BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk, if (sdata) return (unsigned long)sdata->data; - if (flags == BPF_SK_STORAGE_GET_F_CREATE && + if (flags == BPF_LOCAL_STORAGE_GET_F_CREATE && /* Cannot add new elem to a going away sk. * Otherwise, the new elem may become a leak * (and also other memory issues during map @@ -887,14 +958,14 @@ BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk) } const struct bpf_map_ops sk_storage_map_ops = { - .map_alloc_check = bpf_sk_storage_map_alloc_check, - .map_alloc = bpf_sk_storage_map_alloc, - .map_free = bpf_sk_storage_map_free, + .map_alloc_check = bpf_local_storage_map_alloc_check, + .map_alloc = bpf_local_storage_map_alloc, + .map_free = bpf_local_storage_map_free, .map_get_next_key = notsupp_get_next_key, - .map_lookup_elem = bpf_fd_sk_storage_lookup_elem, - .map_update_elem = bpf_fd_sk_storage_update_elem, - .map_delete_elem = bpf_fd_sk_storage_delete_elem, - .map_check_btf = bpf_sk_storage_map_check_btf, + .map_lookup_elem = bpf_sk_storage_lookup_elem, + .map_update_elem = bpf_sk_storage_update_elem, + .map_delete_elem = bpf_sk_storage_delete_elem, + .map_check_btf = bpf_local_storage_map_check_btf, }; const struct bpf_func_proto bpf_sk_storage_get_proto = { @@ -975,7 +1046,7 @@ bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs) u32 nr_maps = 0; int rem, err; - /* bpf_sk_storage_map is currently limited to CAP_SYS_ADMIN as + /* bpf_local_storage_map is currently limited to CAP_SYS_ADMIN as * the map_alloc_check() side also does. */ if (!bpf_capable()) @@ -1025,10 +1096,10 @@ bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs) } EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_alloc); -static int diag_get(struct bpf_sk_storage_data *sdata, struct sk_buff *skb) +static int diag_get(struct bpf_local_storage_data *sdata, struct sk_buff *skb) { struct nlattr *nla_stg, *nla_value; - struct bpf_sk_storage_map *smap; + struct bpf_local_storage_map *smap; /* It cannot exceed max nlattr's payload */ BUILD_BUG_ON(U16_MAX - NLA_HDRLEN < MAX_VALUE_SIZE); @@ -1067,9 +1138,9 @@ static int bpf_sk_storage_diag_put_all(struct sock *sk, struct sk_buff *skb, { /* stg_array_type (e.g. INET_DIAG_BPF_SK_STORAGES) */ unsigned int diag_size = nla_total_size(0); - struct bpf_sk_storage *sk_storage; - struct bpf_sk_storage_elem *selem; - struct bpf_sk_storage_map *smap; + struct bpf_local_storage *sk_storage; + struct bpf_local_storage_elem *selem; + struct bpf_local_storage_map *smap; struct nlattr *nla_stgs; unsigned int saved_len; int err = 0; @@ -1122,8 +1193,8 @@ int bpf_sk_storage_diag_put(struct bpf_sk_storage_diag *diag, { /* stg_array_type (e.g. INET_DIAG_BPF_SK_STORAGES) */ unsigned int diag_size = nla_total_size(0); - struct bpf_sk_storage *sk_storage; - struct bpf_sk_storage_data *sdata; + struct bpf_local_storage *sk_storage; + struct bpf_local_storage_data *sdata; struct nlattr *nla_stgs; unsigned int saved_len; int err = 0; @@ -1150,8 +1221,8 @@ int bpf_sk_storage_diag_put(struct bpf_sk_storage_diag *diag, saved_len = skb->len; for (i = 0; i < diag->nr_maps; i++) { - sdata = __sk_storage_lookup(sk_storage, - (struct bpf_sk_storage_map *)diag->maps[i], + sdata = __local_storage_lookup(sk_storage, + (struct bpf_local_storage_map *)diag->maps[i], false); if (!sdata) diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 5c0e964105ac..a6018ece357f 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -14,8 +14,8 @@ #include #include #include +#include #include -#include #include "../cgroup/cgroup-internal.h" diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index bfd4ccd80847..b1547efcc842 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -7,7 +7,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/net/core/Makefile b/net/core/Makefile index 3e2c378e5f31..9ddc2f3ecd97 100644 --- a/net/core/Makefile +++ b/net/core/Makefile @@ -34,4 +34,3 @@ obj-$(CONFIG_HWBM) += hwbm.o obj-$(CONFIG_NET_DEVLINK) += devlink.o obj-$(CONFIG_GRO_CELLS) += gro_cells.o obj-$(CONFIG_FAILOVER) += failover.o -obj-$(CONFIG_BPF_SYSCALL) += bpf_sk_storage.o diff --git a/net/core/filter.c b/net/core/filter.c index bd2853d23b50..b1556baa1235 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -72,7 +72,7 @@ #include #include #include -#include +#include /** * sk_filter_trim_cap - run a packet through a socket filter diff --git a/net/core/sock.c b/net/core/sock.c index fd85e651ce28..26e25b868dda 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -130,8 +130,8 @@ #include #include +#include #include -#include #include diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c index e3939f76b024..075abf1c6d7e 100644 --- a/net/ipv4/bpf_tcp_ca.c +++ b/net/ipv4/bpf_tcp_ca.c @@ -7,7 +7,7 @@ #include #include #include -#include +#include static u32 optional_ops[] = { offsetof(struct tcp_congestion_ops, init), diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 125f4f8a36b4..ce22867cce5d 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -23,7 +23,7 @@ #include #include #include -#include +#include #include #include diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 97e1fd19ff58..4a202eea15c0 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2788,10 +2788,10 @@ union bpf_attr { * "type". The bpf-local-storage "type" (i.e. the *map*) is * searched against all bpf-local-storages residing at *sk*. * - * An optional *flags* (**BPF_SK_STORAGE_GET_F_CREATE**) can be + * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be * used such that a new bpf-local-storage will be * created if one does not exist. *value* can be used - * together with **BPF_SK_STORAGE_GET_F_CREATE** to specify + * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify * the initial value of a bpf-local-storage. If *value* is * **NULL**, the new bpf-local-storage will be zero initialized. * Return @@ -3388,11 +3388,16 @@ enum { BPF_F_SYSCTL_BASE_NAME = (1ULL << 0), }; -/* BPF_FUNC_sk_storage_get flags */ +/* BPF_FUNC__storage_get flags */ enum { - BPF_SK_STORAGE_GET_F_CREATE = (1ULL << 0), + BPF_LOCAL_STORAGE_GET_F_CREATE = (1ULL << 0), + /* BPF_SK_STORAGE_GET_F_CREATE is only kept for backward compatibility + * and BPF_LOCAL_STORAGE_GET_F_CREATE must be used instead. + */ + BPF_SK_STORAGE_GET_F_CREATE = BPF_LOCAL_STORAGE_GET_F_CREATE, }; + /* BPF_FUNC_read_branch_records flags. */ enum { BPF_F_GET_BRANCH_RECORDS_SIZE = (1ULL << 0), From patchwork Tue May 26 16:33:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KP Singh X-Patchwork-Id: 11570831 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 50CF1159A for ; Tue, 26 May 2020 16:34:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 33AD42073B for ; Tue, 26 May 2020 16:34:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="aIPfLsjZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726930AbgEZQeD (ORCPT ); Tue, 26 May 2020 12:34:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729423AbgEZQdm (ORCPT ); Tue, 26 May 2020 12:33:42 -0400 Received: from mail-wr1-x441.google.com (mail-wr1-x441.google.com [IPv6:2a00:1450:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A533C03E97C for ; Tue, 26 May 2020 09:33:42 -0700 (PDT) Received: by mail-wr1-x441.google.com with SMTP id x13so6394350wrv.4 for ; Tue, 26 May 2020 09:33:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=w+oqiE+dl4Nn+SGx87ajx1fu0RbxYv6VXwk5p+Wjy2w=; b=aIPfLsjZ8az5HMnjEpEJN2VrfzXEg4yi58ahXtoY+VoeXPbbsywnKbkjQhjK2rLI0Z rzw7dP2X52UyTusF6Pobx5t1DUxosya15gJ+BTXGv9JLM12006QdVihdgurL58gnObmW tuTLH+SFYl8Tl10YtBBmAneP03/Iz+Y294Rs0= 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:mime-version:content-transfer-encoding; bh=w+oqiE+dl4Nn+SGx87ajx1fu0RbxYv6VXwk5p+Wjy2w=; b=j7JoO987k/rmPoKnWmZ1D39xD2IGS1jpZSwC7ldpI1MjIg2tXAHF42Ea2uhW4PhxuS Af5/rRTqBxHSq7ZogvIWFU+SLkiVF16l54aHJHh7k5W1CisfFDCdTsF/4jKZHn18kfuj rWd6QT2nW5XvX8wheFtlHCSu3hryR1Bx0rx5c4NOyquEoTL2YCOUuxzravHLCZZJHpJx 1jD1UYlYz5+MT5sZ7hwh9g8pXoK2MDLxmo5tNZf33t3A+Z58+nlLWH+My7n5KryW3L2W u/DRhI/Ey5V++lPLKgI1fCdYQRsOQythdV1l6WqfXKSYNIU2fIRoP7WOFpP8EeXJTtio Tiyg== X-Gm-Message-State: AOAM5338KJAspubnYFPGKsQyFQQLtStZtmnuEedQ1ZehQVSiGd/RTH9r nRgY9DcvDLU6xk+bLTqJk5DgbA== X-Google-Smtp-Source: ABdhPJyHKCzQ/4LSTYapNHIMD11B7Tt/uzke74RLE984cUF24TsbjPP+r+vnSbCcMeL26FjRRhbHcw== X-Received: by 2002:a5d:4282:: with SMTP id k2mr14097928wrq.196.1590510820550; Tue, 26 May 2020 09:33:40 -0700 (PDT) Received: from kpsingh.zrh.corp.google.com ([81.6.44.51]) by smtp.gmail.com with ESMTPSA id k17sm48654wmj.15.2020.05.26.09.33.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 May 2020 09:33:39 -0700 (PDT) From: KP Singh To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , James Morris , Alexander Viro , Martin KaFai Lau , Florent Revest Subject: [PATCH bpf-next 2/4] bpf: Implement bpf_local_storage for inodes Date: Tue, 26 May 2020 18:33:34 +0200 Message-Id: <20200526163336.63653-3-kpsingh@chromium.org> X-Mailer: git-send-email 2.27.0.rc0.183.gde8f92d652-goog In-Reply-To: <20200526163336.63653-1-kpsingh@chromium.org> References: <20200526163336.63653-1-kpsingh@chromium.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: KP Singh Similar to bpf_local_storage for sockets, add local storage for inodes. The life-cycle of storage is managed with the life-cycle of the inode. i.e. the storage is destroyed along with the owning inode. Since, the intention is to use this in LSM programs, the destruction is done after security_inode_free in __destroy_inode. Signed-off-by: KP Singh Reported-by: kbuild test robot --- fs/inode.c | 3 + include/linux/bpf_local_storage.h | 6 + include/linux/bpf_types.h | 1 + include/linux/fs.h | 5 + include/uapi/linux/bpf.h | 41 +++- kernel/bpf/bpf_local_storage.c | 321 +++++++++++++++++++++++++++++- kernel/bpf/syscall.c | 3 +- kernel/bpf/verifier.c | 10 + tools/bpf/bpftool/map.c | 1 + tools/include/uapi/linux/bpf.h | 41 +++- tools/lib/bpf/libbpf_probes.c | 5 +- 11 files changed, 431 insertions(+), 6 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index cc6e701b7e5d..91c81644f33d 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "internal.h" /* @@ -257,6 +258,8 @@ void __destroy_inode(struct inode *inode) security_inode_free(inode); fsnotify_inode_delete(inode); locks_free_lock_context(inode); + bpf_inode_storage_free(inode); + if (!inode->i_nlink) { WARN_ON(atomic_long_read(&inode->i_sb->s_remove_count) == 0); atomic_long_dec(&inode->i_sb->s_remove_count); diff --git a/include/linux/bpf_local_storage.h b/include/linux/bpf_local_storage.h index 85524f18cd91..c6837e7838fc 100644 --- a/include/linux/bpf_local_storage.h +++ b/include/linux/bpf_local_storage.h @@ -9,6 +9,8 @@ void bpf_sk_storage_free(struct sock *sk); extern const struct bpf_func_proto bpf_sk_storage_get_proto; extern const struct bpf_func_proto bpf_sk_storage_delete_proto; +extern const struct bpf_func_proto bpf_inode_storage_get_proto; +extern const struct bpf_func_proto bpf_inode_storage_delete_proto; struct bpf_sk_storage_diag; struct sk_buff; @@ -16,6 +18,7 @@ struct nlattr; struct sock; #ifdef CONFIG_BPF_SYSCALL +void bpf_inode_storage_free(struct inode *inode); int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk); struct bpf_sk_storage_diag * bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs); @@ -35,6 +38,9 @@ bpf_sk_storage_diag_alloc(const struct nlattr *nla) { return NULL; } +static inline void void bpf_inode_storage_free(struct inode *inode) +{ +} static inline void bpf_sk_storage_diag_free(struct bpf_sk_storage_diag *diag) { } diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index 29d22752fc87..07181fb89bdd 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -101,6 +101,7 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_HASH_OF_MAPS, htab_of_maps_map_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP, dev_map_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP_HASH, dev_map_hash_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_SK_STORAGE, sk_storage_map_ops) +BPF_MAP_TYPE(BPF_MAP_TYPE_INODE_STORAGE, inode_storage_map_ops) #if defined(CONFIG_BPF_STREAM_PARSER) BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKMAP, sock_map_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKHASH, sock_hash_ops) diff --git a/include/linux/fs.h b/include/linux/fs.h index 5ee9e583bde2..23a6b8fbd381 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -624,6 +624,7 @@ is_uncached_acl(struct posix_acl *acl) #define IOP_DEFAULT_READLINK 0x0010 struct fsnotify_mark_connector; +struct bpf_local_storage; /* * Keep mostly read-only and often accessed (especially for @@ -740,6 +741,10 @@ struct inode { struct fsverity_info *i_verity_info; #endif +#ifdef CONFIG_BPF_SYSCALL + struct bpf_local_storage __rcu *inode_bpf_storage; +#endif + void *i_private; /* fs or device private pointer */ } __randomize_layout; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 4a202eea15c0..410fb2e5fdd4 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -147,6 +147,7 @@ enum bpf_map_type { BPF_MAP_TYPE_SK_STORAGE, BPF_MAP_TYPE_DEVMAP_HASH, BPF_MAP_TYPE_STRUCT_OPS, + BPF_MAP_TYPE_INODE_STORAGE, }; /* Note that tracing related programs such as @@ -3157,6 +3158,42 @@ union bpf_attr { * **bpf_sk_cgroup_id**\ (). * Return * The id is returned or 0 in case the id could not be retrieved. + * + * void *bpf_inode_storage_get(struct bpf_map *map, void *inode, void *value, u64 flags) + * Description + * Get a bpf_local_storage from an *inode*. + * + * Logically, it could be thought of as getting the value from + * a *map* with *inode* as the **key**. From this + * perspective, the usage is not much different from + * **bpf_map_lookup_elem**\ (*map*, **&**\ *inode*) except this + * helper enforces the key must be an inode and the map must also + * be a **BPF_MAP_TYPE_INODE_STORAGE**. + * + * Underneath, the value is stored locally at *inode* instead of + * the *map*. The *map* is used as the bpf-local-storage + * "type". The bpf-local-storage "type" (i.e. the *map*) is + * searched against all bpf_local_storage residing at *inode*. + * + * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be + * used such that a new bpf_local_storage will be + * created if one does not exist. *value* can be used + * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify + * the initial value of a bpf_local_storage. If *value* is + * **NULL**, the new bpf_local_storage will be zero initialized. + * Return + * A bpf_local_storage pointer is returned on success. + * + * **NULL** if not found or there was an error in adding + * a new bpf_local_storage. + * + * int bpf_inode_storage_delete(struct bpf_map *map, void *inode) + * Description + * Delete a bpf_local_storage from an *inode*. + * Return + * 0 on success. + * + * **-ENOENT** if the bpf_local_storage cannot be found. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3288,7 +3325,9 @@ union bpf_attr { FN(seq_printf), \ FN(seq_write), \ FN(sk_cgroup_id), \ - FN(sk_ancestor_cgroup_id), + FN(sk_ancestor_cgroup_id), \ + FN(inode_storage_get), \ + FN(inode_storage_delete), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index 0a1caac2f5f7..bf807cfe3a73 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -23,6 +23,7 @@ struct bucket { enum bpf_local_storage_type { BPF_LOCAL_STORAGE_SK, + BPF_LOCAL_STORAGE_INODE, }; /* Thp map is not the primary owner of a bpf_local_storage_elem. @@ -94,6 +95,7 @@ struct bpf_local_storage { */ union { struct sock *sk; + struct inode *inode; }; struct rcu_head rcu; raw_spinlock_t lock; /* Protect adding/removing from the "list" */ @@ -165,6 +167,7 @@ static struct bpf_local_storage_elem *sk_selem_alloc( static void __unlink_local_storage(struct bpf_local_storage *local_storage, bool uncharge_omem) { + struct inode *inode; struct sock *sk; switch (local_storage->stype) { @@ -178,6 +181,12 @@ static void __unlink_local_storage(struct bpf_local_storage *local_storage, RCU_INIT_POINTER(sk->sk_bpf_storage, NULL); local_storage->sk = NULL; break; + case BPF_LOCAL_STORAGE_INODE: + inode = local_storage->inode; + /* After this RCU_INIT, sk may be freed and cannot be used */ + RCU_INIT_POINTER(inode->inode_bpf_storage, NULL); + local_storage->inode = NULL; + break; } } @@ -339,6 +348,20 @@ sk_storage_lookup(struct sock *sk, struct bpf_map *map, bool cacheit_lockit) return __local_storage_lookup(sk_storage, smap, cacheit_lockit); } +static struct bpf_local_storage_data *inode_storage_lookup( + struct inode *inode, struct bpf_map *map, bool cacheit_lockit) +{ + struct bpf_local_storage *inode_storage; + struct bpf_local_storage_map *smap; + + inode_storage = rcu_dereference(inode->inode_bpf_storage); + if (!inode_storage) + return NULL; + + smap = (struct bpf_local_storage_map *)map; + return __local_storage_lookup(inode_storage, smap, cacheit_lockit); +} + static int check_flags(const struct bpf_local_storage_data *old_sdata, u64 map_flags) { @@ -435,6 +458,33 @@ static int sk_storage_alloc(struct sock *sk, return err; } +static int inode_storage_alloc(struct inode *inode, + struct bpf_local_storage_map *smap, + struct bpf_local_storage_elem *first_selem) +{ + struct bpf_local_storage *curr; + int err; + + curr = bpf_local_storage_alloc(smap); + if (!curr) + return -ENOMEM; + + curr->inode = inode; + curr->stype = BPF_LOCAL_STORAGE_INODE; + + __selem_link(curr, first_selem); + selem_link_map(smap, first_selem); + + err = publish_local_storage(first_selem, + (struct bpf_local_storage **)&inode->inode_bpf_storage, curr); + if (err) { + kfree(curr); + return err; + } + + return 0; +} + static int check_update_flags(struct bpf_map *map, u64 map_flags) { /* BPF_EXIST and BPF_NOEXIST cannot be both set */ @@ -565,6 +615,109 @@ static struct bpf_local_storage_data *sk_storage_update(struct sock *sk, return ERR_PTR(err); } +static struct bpf_local_storage_data *inode_storage_update( + struct inode *inode, struct bpf_map *map, void *value, u64 map_flags) +{ + struct bpf_local_storage_data *old_sdata = NULL; + struct bpf_local_storage_elem *selem; + struct bpf_local_storage *local_storage; + struct bpf_local_storage_map *smap; + int err; + + err = check_update_flags(map, map_flags); + if (err) + return ERR_PTR(err); + + smap = (struct bpf_local_storage_map *)map; + local_storage = rcu_dereference(inode->inode_bpf_storage); + + if (!local_storage || hlist_empty(&local_storage->list)) { + /* Very first elem for this inode */ + err = check_flags(NULL, map_flags); + if (err) + return ERR_PTR(err); + + selem = selem_alloc(smap, value); + if (!selem) + return ERR_PTR(-ENOMEM); + + err = inode_storage_alloc(inode, smap, selem); + if (err) { + kfree(selem); + return ERR_PTR(err); + } + + return SDATA(selem); + } + + if ((map_flags & BPF_F_LOCK) && !(map_flags & BPF_NOEXIST)) { + /* Hoping to find an old_sdata to do inline update + * such that it can avoid taking the local_storage->lock + * and changing the lists. + */ + old_sdata = __local_storage_lookup(local_storage, smap, false); + err = check_flags(old_sdata, map_flags); + if (err) + return ERR_PTR(err); + + if (old_sdata && selem_linked_to_node(SELEM(old_sdata))) { + copy_map_value_locked(map, old_sdata->data, + value, false); + return old_sdata; + } + } + + raw_spin_lock_bh(&local_storage->lock); + + /* Recheck local_storage->list under local_storage->lock */ + if (unlikely(hlist_empty(&local_storage->list))) { + /* A parallel del is happening and local_storage is going + * away. It has just been checked before, so very + * unlikely. Return instead of retry to keep things + * simple. + */ + err = -EAGAIN; + goto unlock_err; + } + + old_sdata = __local_storage_lookup(local_storage, smap, false); + err = check_flags(old_sdata, map_flags); + if (err) + goto unlock_err; + + if (old_sdata && (map_flags & BPF_F_LOCK)) { + copy_map_value_locked(map, old_sdata->data, value, false); + selem = SELEM(old_sdata); + goto unlock; + } + + selem = selem_alloc(smap, value); + if (!selem) { + err = -ENOMEM; + goto unlock_err; + } + + /* First, link the new selem to the map */ + selem_link_map(smap, selem); + + /* Second, link (and publish) the new selem to sk_storage */ + __selem_link(local_storage, selem); + + /* Third, remove old selem, SELEM(old_sdata) */ + if (old_sdata) { + selem_unlink_map(SELEM(old_sdata)); + __selem_unlink(local_storage, SELEM(old_sdata), false); + } + +unlock: + raw_spin_unlock_bh(&local_storage->lock); + return SDATA(selem); + +unlock_err: + raw_spin_unlock_bh(&local_storage->lock); + return ERR_PTR(err); +} + static int sk_storage_delete(struct sock *sk, struct bpf_map *map) { struct bpf_local_storage_data *sdata; @@ -578,6 +731,19 @@ static int sk_storage_delete(struct sock *sk, struct bpf_map *map) return 0; } +static int inode_storage_delete(struct inode *inode, struct bpf_map *map) +{ + struct bpf_local_storage_data *sdata; + + sdata = inode_storage_lookup(inode, map, false); + if (!sdata) + return -ENOENT; + + selem_unlink(SELEM(sdata)); + + return 0; +} + /* Called by __sk_destruct() & bpf_sk_storage_clone() */ void bpf_sk_storage_free(struct sock *sk) { @@ -617,6 +783,46 @@ void bpf_sk_storage_free(struct sock *sk) kfree_rcu(sk_storage, rcu); } +/* Called by __destroy_inode() */ +void bpf_inode_storage_free(struct inode *inode) +{ + struct bpf_local_storage_elem *selem; + struct bpf_local_storage *local_storage; + bool free_inode_storage = false; + struct hlist_node *n; + + rcu_read_lock(); + local_storage = rcu_dereference(inode->inode_bpf_storage); + if (!local_storage) { + rcu_read_unlock(); + return; + } + + /* Netiher the bpf_prog nor the bpf-map's syscall + * could be modifying the local_storage->list now. + * Thus, no elem can be added-to or deleted-from the + * local_storage->list by the bpf_prog or by the bpf-map's syscall. + * + * It is racing with bpf_local_storage_map_free() alone + * when unlinking elem from the local_storage->list and + * the map's bucket->list. + */ + raw_spin_lock_bh(&local_storage->lock); + hlist_for_each_entry_safe(selem, n, &local_storage->list, snode) { + /* Always unlink from map before unlinking from + * local_storage. + */ + selem_unlink_map(selem); + free_inode_storage = + __selem_unlink(local_storage, selem, false); + } + raw_spin_unlock_bh(&local_storage->lock); + rcu_read_unlock(); + + if (free_inode_storage) + kfree_rcu(local_storage, rcu); +} + static void bpf_local_storage_map_free(struct bpf_map *map) { struct bpf_local_storage_elem *selem; @@ -639,7 +845,7 @@ static void bpf_local_storage_map_free(struct bpf_map *map) * * The elem of this map can be cleaned up here * or by bpf_local_storage_free() during the destruction of the - * owner object. eg. __sk_destruct. + * owner object. eg. __sk_destruct or __destroy_inode. */ for (i = 0; i < (1U << smap->bucket_log); i++) { b = &smap->buckets[i]; @@ -789,6 +995,21 @@ static void *bpf_sk_storage_lookup_elem(struct bpf_map *map, void *key) return ERR_PTR(err); } +static void *bpf_inode_storage_lookup_elem(struct bpf_map *map, void *key) +{ + struct bpf_local_storage_data *sdata; + struct inode *inode; + int err = -EINVAL; + + inode = *(struct inode **)(key); + if (inode) { + sdata = inode_storage_lookup(inode, map, true); + return sdata ? sdata->data : NULL; + } + + return ERR_PTR(err); +} + static int bpf_sk_storage_update_elem(struct bpf_map *map, void *key, void *value, u64 map_flags) { @@ -808,6 +1029,22 @@ static int bpf_sk_storage_update_elem(struct bpf_map *map, void *key, return err; } +static int bpf_inode_storage_update_elem(struct bpf_map *map, void *key, + void *value, u64 map_flags) +{ + struct bpf_local_storage_data *sdata; + struct inode *inode; + int err = -EINVAL; + + inode = *(struct inode **)(key); + if (inode) { + sdata = inode_storage_update(inode, map, value, + map_flags); + return PTR_ERR_OR_ZERO(sdata); + } + return err; +} + static int bpf_sk_storage_delete_elem(struct bpf_map *map, void *key) { struct socket *sock; @@ -823,6 +1060,18 @@ static int bpf_sk_storage_delete_elem(struct bpf_map *map, void *key) return err; } +static int bpf_inode_storage_delete_elem(struct bpf_map *map, void *key) +{ + struct inode *inode; + int err = -EINVAL; + + inode = *(struct inode **)(key); + if (inode) + err = inode_storage_delete(inode, map); + + return err; +} + static struct bpf_local_storage_elem * bpf_sk_storage_clone_elem(struct sock *newsk, struct bpf_local_storage_map *smap, @@ -944,6 +1193,29 @@ BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk, return (unsigned long)NULL; } +BPF_CALL_4(bpf_inode_storage_get, struct bpf_map *, map, struct inode *, inode, + void *, value, u64, flags) +{ + struct bpf_local_storage_data *sdata; + + if (flags > BPF_LOCAL_STORAGE_GET_F_CREATE) + return (unsigned long)NULL; + + sdata = inode_storage_lookup(inode, map, true); + if (sdata) + return (unsigned long)sdata->data; + + if (flags == BPF_LOCAL_STORAGE_GET_F_CREATE && + atomic_inc_not_zero(&inode->i_count)) { + sdata = inode_storage_update(inode, map, value, BPF_NOEXIST); + iput(inode); + return IS_ERR(sdata) ? + (unsigned long)NULL : (unsigned long)sdata->data; + } + + return (unsigned long)NULL; +} + BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk) { if (refcount_inc_not_zero(&sk->sk_refcnt)) { @@ -957,6 +1229,20 @@ BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk) return -ENOENT; } +BPF_CALL_2(bpf_inode_storage_delete, + struct bpf_map *, map, struct inode *, inode) +{ + int err; + + if (atomic_inc_not_zero(&inode->i_count)) { + err = inode_storage_delete(inode, map); + iput(inode); + return err; + } + + return inode_storage_delete(inode, map); +} + const struct bpf_map_ops sk_storage_map_ops = { .map_alloc_check = bpf_local_storage_map_alloc_check, .map_alloc = bpf_local_storage_map_alloc, @@ -968,6 +1254,17 @@ const struct bpf_map_ops sk_storage_map_ops = { .map_check_btf = bpf_local_storage_map_check_btf, }; +const struct bpf_map_ops inode_storage_map_ops = { + .map_alloc_check = bpf_local_storage_map_alloc_check, + .map_alloc = bpf_local_storage_map_alloc, + .map_free = bpf_local_storage_map_free, + .map_get_next_key = notsupp_get_next_key, + .map_lookup_elem = bpf_inode_storage_lookup_elem, + .map_update_elem = bpf_inode_storage_update_elem, + .map_delete_elem = bpf_inode_storage_delete_elem, + .map_check_btf = bpf_local_storage_map_check_btf, +}; + const struct bpf_func_proto bpf_sk_storage_get_proto = { .func = bpf_sk_storage_get, .gpl_only = false, @@ -986,6 +1283,28 @@ const struct bpf_func_proto bpf_sk_storage_delete_proto = { .arg2_type = ARG_PTR_TO_SOCKET, }; +static int bpf_inode_storage_get_btf_ids[4]; +const struct bpf_func_proto bpf_inode_storage_get_proto = { + .func = bpf_inode_storage_get, + .gpl_only = false, + .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL, + .arg1_type = ARG_CONST_MAP_PTR, + .arg2_type = ARG_PTR_TO_BTF_ID, + .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL, + .arg4_type = ARG_ANYTHING, + .btf_id = bpf_inode_storage_get_btf_ids, +}; + +static int bpf_inode_storage_delete_btf_ids[2]; +const struct bpf_func_proto bpf_inode_storage_delete_proto = { + .func = bpf_sk_storage_delete, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_CONST_MAP_PTR, + .arg2_type = ARG_PTR_TO_BTF_ID, + .btf_id = bpf_inode_storage_delete_btf_ids, +}; + struct bpf_sk_storage_diag { u32 nr_maps; struct bpf_map *maps[]; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index d13b804ff045..60407c2d8fbd 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -765,7 +765,8 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf, if (map->map_type != BPF_MAP_TYPE_HASH && map->map_type != BPF_MAP_TYPE_ARRAY && map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && - map->map_type != BPF_MAP_TYPE_SK_STORAGE) + map->map_type != BPF_MAP_TYPE_SK_STORAGE && + map->map_type != BPF_MAP_TYPE_INODE_STORAGE) return -ENOTSUPP; if (map->spin_lock_off + sizeof(struct bpf_spin_lock) > map->value_size) { diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index d2e27dba4ac6..ff90e85e243c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4000,6 +4000,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, func_id != BPF_FUNC_sk_storage_delete) goto error; break; + case BPF_MAP_TYPE_INODE_STORAGE: + if (func_id != BPF_FUNC_inode_storage_get && + func_id != BPF_FUNC_inode_storage_delete) + goto error; + break; default: break; } @@ -4073,6 +4078,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, if (map->map_type != BPF_MAP_TYPE_SK_STORAGE) goto error; break; + case BPF_FUNC_inode_storage_get: + case BPF_FUNC_inode_storage_delete: + if (map->map_type != BPF_MAP_TYPE_INODE_STORAGE) + goto error; + break; default: break; } diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index c5fac8068ba1..e8fbafb3e87b 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -49,6 +49,7 @@ const char * const map_type_name[] = { [BPF_MAP_TYPE_STACK] = "stack", [BPF_MAP_TYPE_SK_STORAGE] = "sk_storage", [BPF_MAP_TYPE_STRUCT_OPS] = "struct_ops", + [BPF_MAP_TYPE_INODE_STORAGE] = "inode_storage", }; const size_t map_type_name_size = ARRAY_SIZE(map_type_name); diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 4a202eea15c0..410fb2e5fdd4 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -147,6 +147,7 @@ enum bpf_map_type { BPF_MAP_TYPE_SK_STORAGE, BPF_MAP_TYPE_DEVMAP_HASH, BPF_MAP_TYPE_STRUCT_OPS, + BPF_MAP_TYPE_INODE_STORAGE, }; /* Note that tracing related programs such as @@ -3157,6 +3158,42 @@ union bpf_attr { * **bpf_sk_cgroup_id**\ (). * Return * The id is returned or 0 in case the id could not be retrieved. + * + * void *bpf_inode_storage_get(struct bpf_map *map, void *inode, void *value, u64 flags) + * Description + * Get a bpf_local_storage from an *inode*. + * + * Logically, it could be thought of as getting the value from + * a *map* with *inode* as the **key**. From this + * perspective, the usage is not much different from + * **bpf_map_lookup_elem**\ (*map*, **&**\ *inode*) except this + * helper enforces the key must be an inode and the map must also + * be a **BPF_MAP_TYPE_INODE_STORAGE**. + * + * Underneath, the value is stored locally at *inode* instead of + * the *map*. The *map* is used as the bpf-local-storage + * "type". The bpf-local-storage "type" (i.e. the *map*) is + * searched against all bpf_local_storage residing at *inode*. + * + * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be + * used such that a new bpf_local_storage will be + * created if one does not exist. *value* can be used + * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify + * the initial value of a bpf_local_storage. If *value* is + * **NULL**, the new bpf_local_storage will be zero initialized. + * Return + * A bpf_local_storage pointer is returned on success. + * + * **NULL** if not found or there was an error in adding + * a new bpf_local_storage. + * + * int bpf_inode_storage_delete(struct bpf_map *map, void *inode) + * Description + * Delete a bpf_local_storage from an *inode*. + * Return + * 0 on success. + * + * **-ENOENT** if the bpf_local_storage cannot be found. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3288,7 +3325,9 @@ union bpf_attr { FN(seq_printf), \ FN(seq_write), \ FN(sk_cgroup_id), \ - FN(sk_ancestor_cgroup_id), + FN(sk_ancestor_cgroup_id), \ + FN(inode_storage_get), \ + FN(inode_storage_delete), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c index 2c92059c0c90..795d7938ab56 100644 --- a/tools/lib/bpf/libbpf_probes.c +++ b/tools/lib/bpf/libbpf_probes.c @@ -170,7 +170,7 @@ int libbpf__load_raw_btf(const char *raw_types, size_t types_len, return btf_fd; } -static int load_sk_storage_btf(void) +static int load_local_storage_btf(void) { const char strs[] = "\0bpf_spin_lock\0val\0cnt\0l"; /* struct bpf_spin_lock { @@ -229,12 +229,13 @@ bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex) key_size = 0; break; case BPF_MAP_TYPE_SK_STORAGE: + case BPF_MAP_TYPE_INODE_STORAGE: btf_key_type_id = 1; btf_value_type_id = 3; value_size = 8; max_entries = 0; map_flags = BPF_F_NO_PREALLOC; - btf_fd = load_sk_storage_btf(); + btf_fd = load_local_storage_btf(); if (btf_fd < 0) return false; break; From patchwork Tue May 26 16:33:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KP Singh X-Patchwork-Id: 11570821 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F09681392 for ; Tue, 26 May 2020 16:33:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0D082073B for ; 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Tue, 26 May 2020 09:33:41 -0700 (PDT) Received: from kpsingh.zrh.corp.google.com ([81.6.44.51]) by smtp.gmail.com with ESMTPSA id k17sm48654wmj.15.2020.05.26.09.33.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 May 2020 09:33:40 -0700 (PDT) From: KP Singh To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , James Morris , Alexander Viro , Martin KaFai Lau , Florent Revest Subject: [PATCH bpf-next 3/4] bpf: Allow local storage to be used from LSM programs Date: Tue, 26 May 2020 18:33:35 +0200 Message-Id: <20200526163336.63653-4-kpsingh@chromium.org> X-Mailer: git-send-email 2.27.0.rc0.183.gde8f92d652-goog In-Reply-To: <20200526163336.63653-1-kpsingh@chromium.org> References: <20200526163336.63653-1-kpsingh@chromium.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: KP Singh Adds support for both bpf_{sk, inode}_storage_{get, delete} to be used in LSM programs. These helpers are not used for tracing programs (currently) as their usage is tied to the life-cycle of the object and should only be used where the owning object won't be freed. Thus, they are safe to use in LSM hooks, but can only be enabled in tracing programs using a whitelist based approach. Since the UAPI helper signature for bpf_sk_storage expect a bpf_sock, it, leads to a compilation warning for LSM programs, it's also updated to accept a void * pointer instead. Signed-off-by: KP Singh --- include/linux/bpf_local_storage.h | 2 ++ kernel/bpf/bpf_local_storage.c | 22 ++++++++++++++++++++++ kernel/bpf/bpf_lsm.c | 20 +++++++++++++++++++- 3 files changed, 43 insertions(+), 1 deletion(-) diff --git a/include/linux/bpf_local_storage.h b/include/linux/bpf_local_storage.h index c6837e7838fc..8982c0c69332 100644 --- a/include/linux/bpf_local_storage.h +++ b/include/linux/bpf_local_storage.h @@ -9,6 +9,8 @@ void bpf_sk_storage_free(struct sock *sk); extern const struct bpf_func_proto bpf_sk_storage_get_proto; extern const struct bpf_func_proto bpf_sk_storage_delete_proto; +extern const struct bpf_func_proto sk_storage_get_btf_proto; +extern const struct bpf_func_proto sk_storage_delete_btf_proto; extern const struct bpf_func_proto bpf_inode_storage_get_proto; extern const struct bpf_func_proto bpf_inode_storage_delete_proto; diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index bf807cfe3a73..07e02d32feb0 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -1305,6 +1305,28 @@ const struct bpf_func_proto bpf_inode_storage_delete_proto = { .btf_id = bpf_inode_storage_delete_btf_ids, }; +static int sk_storage_get_btf_ids[4]; +const struct bpf_func_proto sk_storage_get_btf_proto = { + .func = bpf_sk_storage_get, + .gpl_only = false, + .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL, + .arg1_type = ARG_CONST_MAP_PTR, + .arg2_type = ARG_PTR_TO_BTF_ID, + .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL, + .arg4_type = ARG_ANYTHING, + .btf_id = sk_storage_get_btf_ids, +}; + +static int sk_storage_delete_btf_ids[2]; +const struct bpf_func_proto sk_storage_delete_btf_proto = { + .func = bpf_sk_storage_delete, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_CONST_MAP_PTR, + .arg2_type = ARG_PTR_TO_BTF_ID, + .btf_id = sk_storage_delete_btf_ids, +}; + struct bpf_sk_storage_diag { u32 nr_maps; struct bpf_map *maps[]; diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c index 19636703b24e..fce0a11b63ca 100644 --- a/kernel/bpf/bpf_lsm.c +++ b/kernel/bpf/bpf_lsm.c @@ -11,6 +11,7 @@ #include #include #include +#include /* For every LSM hook that allows attachment of BPF programs, declare a nop * function where a BPF program can be attached. @@ -45,10 +46,27 @@ int bpf_lsm_verify_prog(struct bpf_verifier_log *vlog, return 0; } +static const struct bpf_func_proto * +bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) +{ + switch (func_id) { + case BPF_FUNC_inode_storage_get: + return &bpf_inode_storage_get_proto; + case BPF_FUNC_inode_storage_delete: + return &bpf_inode_storage_delete_proto; + case BPF_FUNC_sk_storage_get: + return &sk_storage_get_btf_proto; + case BPF_FUNC_sk_storage_delete: + return &sk_storage_delete_btf_proto; + default: + return bpf_tracing_func_proto(func_id, prog); + } +} + const struct bpf_prog_ops lsm_prog_ops = { }; const struct bpf_verifier_ops lsm_verifier_ops = { - .get_func_proto = bpf_tracing_func_proto, + .get_func_proto = bpf_lsm_func_proto, .is_valid_access = btf_ctx_access, }; From patchwork Tue May 26 16:33:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KP Singh X-Patchwork-Id: 11570819 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 70BEE159A for ; 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Tue, 26 May 2020 09:33:42 -0700 (PDT) Received: from kpsingh.zrh.corp.google.com ([81.6.44.51]) by smtp.gmail.com with ESMTPSA id k17sm48654wmj.15.2020.05.26.09.33.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 May 2020 09:33:41 -0700 (PDT) From: KP Singh To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , James Morris , Alexander Viro , Martin KaFai Lau , Florent Revest Subject: [PATCH bpf-next 4/4] bpf: Add selftests for local_storage Date: Tue, 26 May 2020 18:33:36 +0200 Message-Id: <20200526163336.63653-5-kpsingh@chromium.org> X-Mailer: git-send-email 2.27.0.rc0.183.gde8f92d652-goog In-Reply-To: <20200526163336.63653-1-kpsingh@chromium.org> References: <20200526163336.63653-1-kpsingh@chromium.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: KP Singh inode_local_storage: * Hook to the file_open and inode_unlink LSM hooks. * Create and unlink a temporary file. * Store some information in the inode's bpf_local_storage during file_open. * Verify that this information exists when the file is unlinked. sk_local_storage: * Hook to the socket_post_create and socket_bind LSM hooks. * Open and bind a socket and set the sk_storage in the socket_post_create hook using the start_server helper. * Verify if the information is set in the socket_bind hook. Signed-off-by: KP Singh --- .../bpf/prog_tests/test_local_storage.c | 60 ++++++++ .../selftests/bpf/progs/local_storage.c | 139 ++++++++++++++++++ 2 files changed, 199 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/test_local_storage.c create mode 100644 tools/testing/selftests/bpf/progs/local_storage.c diff --git a/tools/testing/selftests/bpf/prog_tests/test_local_storage.c b/tools/testing/selftests/bpf/prog_tests/test_local_storage.c new file mode 100644 index 000000000000..ee4e27473c1d --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/test_local_storage.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2020 Google LLC. + */ + +#include +#include + +#include "local_storage.skel.h" +#include "network_helpers.h" + +int create_and_unlink_file(void) +{ + char fname[PATH_MAX] = "/tmp/fileXXXXXX"; + int fd; + + fd = mkstemp(fname); + if (fd < 0) + return fd; + + close(fd); + unlink(fname); + return 0; +} + +void test_test_local_storage(void) +{ + struct local_storage *skel = NULL; + int err, duration = 0, serv_sk = -1; + + skel = local_storage__open_and_load(); + if (CHECK(!skel, "skel_load", "lsm skeleton failed\n")) + goto close_prog; + + err = local_storage__attach(skel); + if (CHECK(err, "attach", "lsm attach failed: %d\n", err)) + goto close_prog; + + skel->bss->monitored_pid = getpid(); + + err = create_and_unlink_file(); + if (CHECK(err < 0, "exec_cmd", "err %d errno %d\n", err, errno)) + goto close_prog; + + CHECK(!skel->bss->inode_storage_result, "inode_storage_result", + "inode_local_storage not set"); + + serv_sk = start_server(AF_INET6, SOCK_STREAM); + if (CHECK(serv_sk < 0, "start_server", "failed to start server\n")) + goto close_prog; + + CHECK(!skel->bss->sk_storage_result, "sk_storage_result", + "sk_local_storage not set"); + + close(serv_sk); + +close_prog: + local_storage__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/local_storage.c b/tools/testing/selftests/bpf/progs/local_storage.c new file mode 100644 index 000000000000..1aa4ccbe0369 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/local_storage.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright 2020 Google LLC. + */ + +#include +#include +#include +#include +#include +#include + +char _license[] SEC("license") = "GPL"; +__u32 _version SEC("version") = 1; + +#define DUMMY_STORAGE_VALUE 0xdeadbeef + +int monitored_pid = 0; +bool inode_storage_result = false; +bool sk_storage_result = false; + +struct dummy_storage { + __u32 value; +}; + +struct { + __uint(type, BPF_MAP_TYPE_INODE_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, struct dummy_storage); +} inode_storage_map SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_SK_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC | BPF_F_CLONE); + __type(key, int); + __type(value, struct dummy_storage); +} sk_storage_map SEC(".maps"); + +/* Using vmlinux.h causes the generated BTF to be so big that the object + * load fails at btf__load. + */ +struct sock {} __attribute__((preserve_access_index)); +struct sockaddr {} __attribute__((preserve_access_index)); +struct socket { + struct sock *sk; +} __attribute__((preserve_access_index)); + +struct inode {} __attribute__((preserve_access_index)); +struct dentry { + struct inode *d_inode; +} __attribute__((preserve_access_index)); +struct file { + struct inode *f_inode; +} __attribute__((preserve_access_index)); + + +SEC("lsm/inode_unlink") +int BPF_PROG(unlink_hook, struct inode *dir, struct dentry *victim) +{ + __u32 pid = bpf_get_current_pid_tgid() >> 32; + struct dummy_storage *storage; + + if (pid != monitored_pid) + return 0; + + storage = bpf_inode_storage_get(&inode_storage_map, victim->d_inode, 0, + BPF_SK_STORAGE_GET_F_CREATE); + if (!storage) + return 0; + + if (storage->value == DUMMY_STORAGE_VALUE) + inode_storage_result = true; + + return 0; +} + +SEC("lsm/socket_bind") +int BPF_PROG(socket_bind, struct socket *sock, struct sockaddr *address, + int addrlen) +{ + __u32 pid = bpf_get_current_pid_tgid() >> 32; + struct dummy_storage *storage; + + if (pid != monitored_pid) + return 0; + + storage = bpf_sk_storage_get(&sk_storage_map, sock->sk, 0, + BPF_SK_STORAGE_GET_F_CREATE); + if (!storage) + return 0; + + if (storage->value == DUMMY_STORAGE_VALUE) + sk_storage_result = true; + + return 0; +} + +SEC("lsm/socket_post_create") +int BPF_PROG(socket_post_create, struct socket *sock, int family, int type, + int protocol, int kern) +{ + __u32 pid = bpf_get_current_pid_tgid() >> 32; + struct dummy_storage *storage; + + if (pid != monitored_pid) + return 0; + + storage = bpf_sk_storage_get(&sk_storage_map, sock->sk, 0, + BPF_SK_STORAGE_GET_F_CREATE); + if (!storage) + return 0; + + storage->value = DUMMY_STORAGE_VALUE; + + return 0; +} + +SEC("lsm/file_open") +int BPF_PROG(test_int_hook, struct file *file) +{ + __u32 pid = bpf_get_current_pid_tgid() >> 32; + struct dummy_storage *storage; + + if (pid != monitored_pid) + return 0; + + if (!file->f_inode) + return 0; + + storage = bpf_inode_storage_get(&inode_storage_map, file->f_inode, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (!storage) + return 0; + + storage->value = DUMMY_STORAGE_VALUE; + return 0; +}