From patchwork Mon Aug 3 16:46:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KP Singh X-Patchwork-Id: 11698413 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 D81E4912 for ; Mon, 3 Aug 2020 16:47:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF7D02086A for ; Mon, 3 Aug 2020 16:47:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="DI6S+OL7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727930AbgHCQr3 (ORCPT ); Mon, 3 Aug 2020 12:47:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54374 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727015AbgHCQrE (ORCPT ); Mon, 3 Aug 2020 12:47:04 -0400 Received: from mail-ed1-x543.google.com (mail-ed1-x543.google.com [IPv6:2a00:1450:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 483BFC061756 for ; Mon, 3 Aug 2020 09:47:04 -0700 (PDT) Received: by mail-ed1-x543.google.com with SMTP id c15so18049112edj.3 for ; Mon, 03 Aug 2020 09:47:04 -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=drcXcueQUUcJSi8NlA/mDvV9Ce3EgLR7Xw1xNTIxmTE=; b=DI6S+OL7u5aHyGD3HjXikStCNWIZyNjkreSoQUNWCLF2pC3BE/f23g2m8eliEZVlj3 bUPJP3uoS4k7da9Mv4hPFYl/VfuMT+1tZ8EYU6Svb0DU6Ue0U7FUib1SHaYTsLKxpGhe KTc5TqssjJY247bsIouxKrAsGsQj0eftArscc= 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=drcXcueQUUcJSi8NlA/mDvV9Ce3EgLR7Xw1xNTIxmTE=; b=V15w3N6WytkkZs7gc8zTvUXWIruzCSRZ4NoHz++wMMvy/AgGar+0O1PjxgRZrbHnFq zKY9opFj1zEraiyoZyq7Xj2Vy23Jic/nv9J4DYrdnIz5xlExL4DXQ9R2I31AavDgBImn e9+jeNVOLKge9JXgnlDIVW2ZriyDFJJ4XbgAEH/xzRWQKo5KEdtET3RSH+m/JJl+B17x afNE0PXmQECfz2j5LpL7yFj7r8VE70bFcaQHTWxJNni3+aS2ZkHGdgUCy2HRKTB9BEeQ vHhbPetrgG1o8vxiuzUlpH3ra5ttPBhVSjaMHwNPOF5ajK9k84WFyL21sGda/5eZQEQg q1UQ== X-Gm-Message-State: AOAM531++ckud8DZgznG7heCjKQ+3HQlZkWQrfA+2FlHjHcveMUXPwE6 nVf3InGBFath5J7moJdbtTJ/lg== X-Google-Smtp-Source: ABdhPJyFOvMKPJ3P0oDka8wJLFTgCWG2nyInTfIfl5FnLY4ms4AxUrMO4iGX80fDbgG868YbUZNs1w== X-Received: by 2002:aa7:dd5a:: with SMTP id o26mr17194629edw.197.1596473222749; Mon, 03 Aug 2020 09:47:02 -0700 (PDT) Received: from kpsingh.zrh.corp.google.com ([81.6.44.51]) by smtp.gmail.com with ESMTPSA id j7sm16385654ejb.64.2020.08.03.09.47.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Aug 2020 09:47:02 -0700 (PDT) From: KP Singh To: linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org Cc: Martin KaFai Lau , Alexei Starovoitov , Daniel Borkmann , Paul Turner , Jann Horn , Florent Revest Subject: [PATCH bpf-next v8 3/7] bpf: Generalize bpf_sk_storage Date: Mon, 3 Aug 2020 18:46:51 +0200 Message-Id: <20200803164655.1924498-4-kpsingh@chromium.org> X-Mailer: git-send-email 2.28.0.163.g6104cc2f0b6-goog In-Reply-To: <20200803164655.1924498-1-kpsingh@chromium.org> References: <20200803164655.1924498-1-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. 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. This includes the changes suggested by Martin in: https://lore.kernel.org/bpf/20200725013047.4006241-1-kafai@fb.com/ which adds map_local_storage_charge, map_local_storage_uncharge, and map_owner_storage_ptr. Co-developed-by: Martin KaFai Lau Signed-off-by: KP Singh --- include/linux/bpf.h | 9 ++ include/net/bpf_sk_storage.h | 51 +++++++ include/uapi/linux/bpf.h | 8 +- net/core/bpf_sk_storage.c | 246 +++++++++++++++++++++------------ tools/include/uapi/linux/bpf.h | 8 +- 5 files changed, 233 insertions(+), 89 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index cef4ef0d2b4e..8e1e23c60dc7 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -34,6 +34,9 @@ struct btf_type; struct exception_table_entry; struct seq_operations; struct bpf_iter_aux_info; +struct bpf_local_storage; +struct bpf_local_storage_map; +struct bpf_local_storage_elem; extern struct idr btf_idr; extern spinlock_t btf_idr_lock; @@ -104,6 +107,12 @@ struct bpf_map_ops { __poll_t (*map_poll)(struct bpf_map *map, struct file *filp, struct poll_table_struct *pts); + /* Functions called by bpf_local_storage maps */ + int (*map_local_storage_charge)(struct bpf_local_storage_map *smap, + void *owner, u32 size); + void (*map_local_storage_uncharge)(struct bpf_local_storage_map *smap, + void *owner, u32 size); + struct bpf_local_storage __rcu ** (*map_owner_storage_ptr)(void *owner); /* BTF name and id of struct allocated by map_alloc */ const char * const map_btf_name; int *map_btf_id; diff --git a/include/net/bpf_sk_storage.h b/include/net/bpf_sk_storage.h index 950c5aaba15e..05b777950eb3 100644 --- a/include/net/bpf_sk_storage.h +++ b/include/net/bpf_sk_storage.h @@ -3,8 +3,15 @@ #ifndef _BPF_SK_STORAGE_H #define _BPF_SK_STORAGE_H +#include +#include +#include #include #include +#include +#include +#include +#include struct sock; @@ -34,6 +41,50 @@ u16 bpf_local_storage_cache_idx_get(struct bpf_local_storage_cache *cache); void bpf_local_storage_cache_idx_free(struct bpf_local_storage_cache *cache, u16 idx); +/* Helper functions for bpf_local_storage */ +int bpf_local_storage_map_alloc_check(union bpf_attr *attr); + +struct bpf_local_storage_map *bpf_local_storage_map_alloc(union bpf_attr *attr); + +struct bpf_local_storage_data * +bpf_local_storage_lookup(struct bpf_local_storage *local_storage, + struct bpf_local_storage_map *smap, + bool cacheit_lockit); + +void bpf_local_storage_map_free(struct bpf_local_storage_map *smap); + +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); + +void bpf_selem_link_storage(struct bpf_local_storage *local_storage, + struct bpf_local_storage_elem *selem); + +bool bpf_selem_unlink_storage(struct bpf_local_storage *local_storage, + struct bpf_local_storage_elem *selem, + bool uncharge_omem); + +void bpf_selem_unlink(struct bpf_local_storage_elem *selem); + +void bpf_selem_link_map(struct bpf_local_storage_map *smap, + struct bpf_local_storage_elem *selem); + +void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem); + +struct bpf_local_storage_elem * +bpf_selem_alloc(struct bpf_local_storage_map *smap, void *owner, void *value, + bool charge_mem); + +int +bpf_local_storage_alloc(void *owner, + struct bpf_local_storage_map *smap, + struct bpf_local_storage_elem *first_selem); + +struct bpf_local_storage_data * +bpf_local_storage_update(void *owner, struct bpf_map *map, void *value, + u64 map_flags); + #ifdef CONFIG_BPF_SYSCALL int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk); struct bpf_sk_storage_diag * diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index b134e679e9db..35629752cec8 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3647,9 +3647,13 @@ 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. */ diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c index 99dde7b74767..bb2375769ca1 100644 --- a/net/core/bpf_sk_storage.c +++ b/net/core/bpf_sk_storage.c @@ -84,7 +84,7 @@ struct bpf_local_storage_elem { struct bpf_local_storage { struct bpf_local_storage_data __rcu *cache[BPF_LOCAL_STORAGE_CACHE_SIZE]; struct hlist_head list; /* List of bpf_local_storage_elem */ - struct sock *owner; /* The object that owns the the above "list" of + void *owner; /* The object that owns the the above "list" of * bpf_local_storage_elem. */ struct rcu_head rcu; @@ -110,6 +110,33 @@ static int omem_charge(struct sock *sk, unsigned int size) return -ENOMEM; } +static int mem_charge(struct bpf_local_storage_map *smap, void *owner, u32 size) +{ + struct bpf_map *map = &smap->map; + + if (!map->ops->map_local_storage_charge) + return 0; + + return map->ops->map_local_storage_charge(smap, owner, size); +} + +static void mem_uncharge(struct bpf_local_storage_map *smap, void *owner, + u32 size) +{ + struct bpf_map *map = &smap->map; + + if (map->ops->map_local_storage_uncharge) + map->ops->map_local_storage_uncharge(smap, owner, size); +} + +static struct bpf_local_storage __rcu ** +owner_storage(struct bpf_local_storage_map *smap, void *owner) +{ + struct bpf_map *map = &smap->map; + + return map->ops->map_owner_storage_ptr(owner); +} + static bool selem_linked_to_storage(const struct bpf_local_storage_elem *selem) { return !hlist_unhashed(&selem->snode); @@ -120,13 +147,13 @@ static bool selem_linked_to_map(const struct bpf_local_storage_elem *selem) return !hlist_unhashed(&selem->map_node); } -static struct bpf_local_storage_elem * -bpf_selem_alloc(struct bpf_local_storage_map *smap, struct sock *sk, - void *value, bool charge_omem) +struct bpf_local_storage_elem * +bpf_selem_alloc(struct bpf_local_storage_map *smap, void *owner, + void *value, bool charge_mem) { struct bpf_local_storage_elem *selem; - if (charge_omem && omem_charge(sk, smap->elem_size)) + if (charge_mem && mem_charge(smap, owner, smap->elem_size)) return NULL; selem = kzalloc(smap->elem_size, GFP_ATOMIC | __GFP_NOWARN); @@ -136,40 +163,42 @@ bpf_selem_alloc(struct bpf_local_storage_map *smap, struct sock *sk, return selem; } - if (charge_omem) - atomic_sub(smap->elem_size, &sk->sk_omem_alloc); + if (charge_mem) + mem_uncharge(smap, owner, smap->elem_size); return NULL; } -/* sk_storage->lock must be held and selem->sk_storage == sk_storage. +/* local_storage->lock must be held and selem->sk_storage == sk_storage. * The caller must ensure selem->smap is still valid to be * dereferenced for its smap->elem_size and smap->cache_idx. */ -static bool bpf_selem_unlink_storage(struct bpf_local_storage *local_storage, - struct bpf_local_storage_elem *selem, - bool uncharge_omem) +bool bpf_selem_unlink_storage(struct bpf_local_storage *local_storage, + struct bpf_local_storage_elem *selem, + bool uncharge_mem) { struct bpf_local_storage_map *smap; bool free_local_storage; - struct sock *sk; + void *owner; smap = rcu_dereference(SDATA(selem)->smap); - sk = local_storage->owner; + owner = local_storage->owner; - /* All uncharging on sk->sk_omem_alloc must be done first. - * sk may be freed once the last selem is unlinked from local_storage. + /* All uncharging on owner must be done first. + * The owner may be freed once the last selem is unlinked from + * local_storage. */ - if (uncharge_omem) - atomic_sub(smap->elem_size, &sk->sk_omem_alloc); + if (uncharge_mem) + mem_uncharge(smap, owner, smap->elem_size); free_local_storage = hlist_is_singular_node(&selem->snode, &local_storage->list); if (free_local_storage) { - atomic_sub(sizeof(struct bpf_local_storage), &sk->sk_omem_alloc); + mem_uncharge(smap, owner, sizeof(struct bpf_local_storage)); local_storage->owner = NULL; - /* After this RCU_INIT, sk may be freed and cannot be used */ - RCU_INIT_POINTER(sk->sk_bpf_storage, NULL); + + /* After this RCU_INIT, owner may be freed and cannot be used */ + RCU_INIT_POINTER(*owner_storage(smap, owner), NULL); /* local_storage is not freed now. local_storage->lock is * still held and raw_spin_unlock_bh(&local_storage->lock) @@ -215,14 +244,14 @@ static void __bpf_selem_unlink_storage(struct bpf_local_storage_elem *selem) kfree_rcu(local_storage, rcu); } -static void bpf_selem_link_storage(struct bpf_local_storage *local_storage, - struct bpf_local_storage_elem *selem) +void bpf_selem_link_storage(struct bpf_local_storage *local_storage, + struct bpf_local_storage_elem *selem) { RCU_INIT_POINTER(selem->local_storage, local_storage); hlist_add_head(&selem->snode, &local_storage->list); } -static void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem) +void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem) { struct bpf_local_storage_map *smap; struct bpf_local_storage_map_bucket *b; @@ -239,8 +268,8 @@ static void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem) raw_spin_unlock_bh(&b->lock); } -static void bpf_selem_link_map(struct bpf_local_storage_map *smap, - struct bpf_local_storage_elem *selem) +void bpf_selem_link_map(struct bpf_local_storage_map *smap, + struct bpf_local_storage_elem *selem) { struct bpf_local_storage_map_bucket *b = select_bucket(smap, selem); @@ -250,7 +279,7 @@ static void bpf_selem_link_map(struct bpf_local_storage_map *smap, raw_spin_unlock_bh(&b->lock); } -static void bpf_selem_unlink(struct bpf_local_storage_elem *selem) +void bpf_selem_unlink(struct bpf_local_storage_elem *selem) { /* Always unlink from map before unlinking from local_storage * because selem will be freed after successfully unlinked from @@ -260,7 +289,7 @@ static void bpf_selem_unlink(struct bpf_local_storage_elem *selem) __bpf_selem_unlink_storage(selem); } -static struct bpf_local_storage_data * +struct bpf_local_storage_data * bpf_local_storage_lookup(struct bpf_local_storage *local_storage, struct bpf_local_storage_map *smap, bool cacheit_lockit) @@ -326,40 +355,45 @@ static int check_flags(const struct bpf_local_storage_data *old_sdata, return 0; } -static int sk_storage_alloc(struct sock *sk, +int bpf_local_storage_alloc(void *owner, struct bpf_local_storage_map *smap, struct bpf_local_storage_elem *first_selem) { - struct bpf_local_storage *prev_sk_storage, *sk_storage; + struct bpf_local_storage *prev_storage, *storage; + struct bpf_local_storage **owner_storage_ptr; int err; - err = omem_charge(sk, sizeof(*sk_storage)); + err = mem_charge(smap, owner, sizeof(*storage)); if (err) return err; - sk_storage = kzalloc(sizeof(*sk_storage), GFP_ATOMIC | __GFP_NOWARN); - if (!sk_storage) { + storage = kzalloc(sizeof(*storage), GFP_ATOMIC | __GFP_NOWARN); + if (!storage) { err = -ENOMEM; goto uncharge; } - INIT_HLIST_HEAD(&sk_storage->list); - raw_spin_lock_init(&sk_storage->lock); - sk_storage->owner = sk; - bpf_selem_link_storage(sk_storage, first_selem); + INIT_HLIST_HEAD(&storage->list); + raw_spin_lock_init(&storage->lock); + storage->owner = owner; + + bpf_selem_link_storage(storage, first_selem); bpf_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. + + owner_storage_ptr = + (struct bpf_local_storage **)owner_storage(smap, owner); + /* Publish storage to the owner. + * Instead of using any lock of the kernel object (i.e. owner), + * cmpxchg will work with any kernel object regardless what + * the running context is, bh, irq...etc. * - * 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. + * From now on, the owner->storage pointer (e.g. sk->sk_bpf_storage) + * is protected by the storage->lock. Hence, when freeing + * the owner->storage, the storage->lock must be held before + * setting owner->storage ptr to NULL. */ - prev_sk_storage = cmpxchg((struct bpf_local_storage **)&sk->sk_bpf_storage, - NULL, sk_storage); - if (unlikely(prev_sk_storage)) { + prev_storage = cmpxchg(owner_storage_ptr, NULL, storage); + if (unlikely(prev_storage)) { bpf_selem_unlink_map(first_selem); err = -EAGAIN; goto uncharge; @@ -367,7 +401,7 @@ static int sk_storage_alloc(struct sock *sk, /* 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(). @@ -377,8 +411,8 @@ static int sk_storage_alloc(struct sock *sk, return 0; uncharge: - kfree(sk_storage); - atomic_sub(sizeof(*sk_storage), &sk->sk_omem_alloc); + kfree(storage); + mem_uncharge(smap, owner, sizeof(*storage)); return err; } @@ -387,9 +421,9 @@ static int sk_storage_alloc(struct sock *sk, * Otherwise, it will become a leak (and other memory issues * during map destruction). */ -static struct bpf_local_storage_data * -bpf_local_storage_update(struct sock *sk, struct bpf_map *map, void *value, - u64 map_flags) +struct bpf_local_storage_data * +bpf_local_storage_update(void *owner, struct bpf_map *map, + void *value, u64 map_flags) { struct bpf_local_storage_data *old_sdata = NULL; struct bpf_local_storage_elem *selem; @@ -404,21 +438,21 @@ bpf_local_storage_update(struct sock *sk, struct bpf_map *map, void *value, return ERR_PTR(-EINVAL); smap = (struct bpf_local_storage_map *)map; - local_storage = rcu_dereference(sk->sk_bpf_storage); + local_storage = rcu_dereference(*owner_storage(smap, owner)); if (!local_storage || hlist_empty(&local_storage->list)) { - /* Very first elem for this object */ + /* Very first elem for the owner */ err = check_flags(NULL, map_flags); if (err) return ERR_PTR(err); - selem = bpf_selem_alloc(smap, sk, value, true); + selem = bpf_selem_alloc(smap, owner, value, true); if (!selem) return ERR_PTR(-ENOMEM); - err = sk_storage_alloc(sk, smap, selem); + err = bpf_local_storage_alloc(owner, smap, selem); if (err) { kfree(selem); - atomic_sub(smap->elem_size, &sk->sk_omem_alloc); + mem_uncharge(smap, owner, smap->elem_size); return ERR_PTR(err); } @@ -430,8 +464,8 @@ bpf_local_storage_update(struct sock *sk, struct bpf_map *map, void *value, * such that it can avoid taking the local_storage->lock * and changing the lists. */ - old_sdata = - bpf_local_storage_lookup(local_storage, smap, false); + old_sdata = bpf_local_storage_lookup(local_storage, smap, + false); err = check_flags(old_sdata, map_flags); if (err) return ERR_PTR(err); @@ -475,7 +509,7 @@ bpf_local_storage_update(struct sock *sk, struct bpf_map *map, void *value, * old_sdata will not be uncharged later during * bpf_selem_unlink_storage(). */ - selem = bpf_selem_alloc(smap, sk, value, !old_sdata); + selem = bpf_selem_alloc(smap, owner, value, !old_sdata); if (!selem) { err = -ENOMEM; goto unlock_err; @@ -567,7 +601,7 @@ void bpf_sk_storage_free(struct sock *sk) * 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. * - * 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. */ @@ -587,17 +621,12 @@ void bpf_sk_storage_free(struct sock *sk) kfree_rcu(sk_storage, rcu); } -static void bpf_local_storage_map_free(struct bpf_map *map) +void bpf_local_storage_map_free(struct bpf_local_storage_map *smap) { struct bpf_local_storage_elem *selem; - struct bpf_local_storage_map *smap; struct bpf_local_storage_map_bucket *b; unsigned int i; - smap = (struct bpf_local_storage_map *)map; - - bpf_local_storage_cache_idx_free(&sk_cache, smap->cache_idx); - /* Note that this map might be concurrently cloned from * bpf_sk_storage_clone. Wait for any existing bpf_sk_storage_clone * RCU read section to finish before proceeding. New RCU @@ -607,11 +636,12 @@ static void bpf_local_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(). + * 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]; @@ -627,22 +657,31 @@ static void bpf_local_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 * bpf_selem_unlink_storage(). * * Hence, wait another rcu grace period for the - * bpf_sk_storage_free() to finish. + * bpf_local_storage_free() to finish. */ synchronize_rcu(); kvfree(smap->buckets); - kfree(map); + kfree(smap); +} + +static void sk_storage_map_free(struct bpf_map *map) +{ + struct bpf_local_storage_map *smap; + + smap = (struct bpf_local_storage_map *)map; + bpf_local_storage_cache_idx_free(&sk_cache, smap->cache_idx); + bpf_local_storage_map_free(smap); } /* U16_MAX is much more than enough for sk local storage @@ -654,7 +693,7 @@ static void bpf_local_storage_map_free(struct bpf_map *map) sizeof(struct bpf_local_storage_elem)), \ (U16_MAX - sizeof(struct bpf_local_storage_elem))) -static int bpf_local_storage_map_alloc_check(union bpf_attr *attr) +int bpf_local_storage_map_alloc_check(union bpf_attr *attr) { if (attr->map_flags & ~BPF_LOCAL_STORAGE_CREATE_FLAG_MASK || !(attr->map_flags & BPF_F_NO_PREALLOC) || @@ -673,7 +712,7 @@ static int bpf_local_storage_map_alloc_check(union bpf_attr *attr) return 0; } -static struct bpf_map *bpf_local_storage_map_alloc(union bpf_attr *attr) +struct bpf_local_storage_map *bpf_local_storage_map_alloc(union bpf_attr *attr) { struct bpf_local_storage_map *smap; unsigned int i; @@ -711,9 +750,21 @@ static struct bpf_map *bpf_local_storage_map_alloc(union bpf_attr *attr) raw_spin_lock_init(&smap->buckets[i].lock); } - smap->elem_size = sizeof(struct bpf_local_storage_elem) + attr->value_size; - smap->cache_idx = bpf_local_storage_cache_idx_get(&sk_cache); + smap->elem_size = + sizeof(struct bpf_local_storage_elem) + attr->value_size; + + return smap; +} + +static struct bpf_map *sk_storage_map_alloc(union bpf_attr *attr) +{ + struct bpf_local_storage_map *smap; + smap = bpf_local_storage_map_alloc(attr); + if (IS_ERR(smap)) + return ERR_CAST(smap); + + smap->cache_idx = bpf_local_storage_cache_idx_get(&sk_cache); return &smap->map; } @@ -723,10 +774,10 @@ static int notsupp_get_next_key(struct bpf_map *map, void *key, return -ENOTSUPP; } -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) +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) { u32 int_data; @@ -857,7 +908,7 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) bpf_selem_link_map(smap, copy_selem); bpf_selem_link_storage(new_sk_storage, copy_selem); } else { - ret = sk_storage_alloc(newsk, smap, copy_selem); + ret = bpf_local_storage_alloc(newsk, smap, copy_selem); if (ret) { kfree(copy_selem); atomic_sub(smap->elem_size, @@ -926,11 +977,33 @@ BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk) return -ENOENT; } +static int sk_storage_charge(struct bpf_local_storage_map *smap, + void *owner, u32 size) +{ + return omem_charge(owner, size); +} + +static void sk_storage_uncharge(struct bpf_local_storage_map *smap, + void *owner, u32 size) +{ + struct sock *sk = owner; + + atomic_sub(size, &sk->sk_omem_alloc); +} + +static struct bpf_local_storage __rcu ** +sk_storage_ptr(void *owner) +{ + struct sock *sk = owner; + + return &sk->sk_bpf_storage; +} + static int sk_storage_map_btf_id; 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, - .map_free = bpf_local_storage_map_free, + .map_alloc = sk_storage_map_alloc, + .map_free = sk_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, @@ -938,6 +1011,9 @@ const struct bpf_map_ops sk_storage_map_ops = { .map_check_btf = bpf_local_storage_map_check_btf, .map_btf_name = "bpf_local_storage_map", .map_btf_id = &sk_storage_map_btf_id, + .map_local_storage_charge = sk_storage_charge, + .map_local_storage_uncharge = sk_storage_uncharge, + .map_owner_storage_ptr = sk_storage_ptr, }; const struct bpf_func_proto bpf_sk_storage_get_proto = { diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index b134e679e9db..35629752cec8 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3647,9 +3647,13 @@ 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. */