From patchwork Mon Mar 6 08:42:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin KaFai Lau X-Patchwork-Id: 13160693 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7A81C61DA4 for ; Mon, 6 Mar 2023 08:42:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229669AbjCFImp (ORCPT ); Mon, 6 Mar 2023 03:42:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230035AbjCFImn (ORCPT ); Mon, 6 Mar 2023 03:42:43 -0500 Received: from out-32.mta1.migadu.com (out-32.mta1.migadu.com [IPv6:2001:41d0:203:375::20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BEA021A2D for ; Mon, 6 Mar 2023 00:42:38 -0800 (PST) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1678092156; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=mG9ny22TJnv5fADTa9Df7jr5HgSSaMS9BRh8kOuiZGA=; b=UHf7LZ77OqpYDKo8G2LR1LNPEOO7g2n4ljLZZ6DbWpErqBN0jHz5QQg5CLJ9cksE4ak096 uotbAvm+9IVxu8P242al+apPUL6GmbKhEhbqqXDLMDAAeCM9hVL0hHUlqTyAgF7K/bOYtv 0Qxv2o0t+84Tsi4JfiEJWfgywqGGKzI= From: Martin KaFai Lau To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , kernel-team@meta.com Subject: [PATCH bpf-next 02/16] bpf: Refactor codes into bpf_local_storage_destroy Date: Mon, 6 Mar 2023 00:42:02 -0800 Message-Id: <20230306084216.3186830-3-martin.lau@linux.dev> In-Reply-To: <20230306084216.3186830-1-martin.lau@linux.dev> References: <20230306084216.3186830-1-martin.lau@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Martin KaFai Lau This patch first renames bpf_local_storage_unlink_nolock to bpf_local_storage_destroy(). It better reflects that it is only used when the storage's owner (sk/task/cgrp/inode) is being kfree(). All bpf_local_storage_destroy's caller is taking the spin lock and then free the storage. This patch also moves these two steps into the bpf_local_storage_destroy. This is a preparation work for a later patch that uses bpf_mem_cache_alloc/free in the bpf_local_storage. Signed-off-by: Martin KaFai Lau --- include/linux/bpf_local_storage.h | 2 +- kernel/bpf/bpf_cgrp_storage.c | 9 +-------- kernel/bpf/bpf_inode_storage.c | 8 +------- kernel/bpf/bpf_local_storage.c | 8 ++++++-- kernel/bpf/bpf_task_storage.c | 9 +-------- net/core/bpf_sk_storage.c | 8 +------- 6 files changed, 11 insertions(+), 33 deletions(-) diff --git a/include/linux/bpf_local_storage.h b/include/linux/bpf_local_storage.h index 6917c9a408a1..c8dcf6f40497 100644 --- a/include/linux/bpf_local_storage.h +++ b/include/linux/bpf_local_storage.h @@ -128,7 +128,7 @@ bpf_local_storage_lookup(struct bpf_local_storage *local_storage, struct bpf_local_storage_map *smap, bool cacheit_lockit); -bool bpf_local_storage_unlink_nolock(struct bpf_local_storage *local_storage); +void bpf_local_storage_destroy(struct bpf_local_storage *local_storage); void bpf_local_storage_map_free(struct bpf_map *map, struct bpf_local_storage_cache *cache, diff --git a/kernel/bpf/bpf_cgrp_storage.c b/kernel/bpf/bpf_cgrp_storage.c index 6cdf6d9ed91d..1d00f1d9bdb7 100644 --- a/kernel/bpf/bpf_cgrp_storage.c +++ b/kernel/bpf/bpf_cgrp_storage.c @@ -46,8 +46,6 @@ static struct bpf_local_storage __rcu **cgroup_storage_ptr(void *owner) void bpf_cgrp_storage_free(struct cgroup *cgroup) { struct bpf_local_storage *local_storage; - bool free_cgroup_storage = false; - unsigned long flags; rcu_read_lock(); local_storage = rcu_dereference(cgroup->bpf_cgrp_storage); @@ -57,14 +55,9 @@ void bpf_cgrp_storage_free(struct cgroup *cgroup) } bpf_cgrp_storage_lock(); - raw_spin_lock_irqsave(&local_storage->lock, flags); - free_cgroup_storage = bpf_local_storage_unlink_nolock(local_storage); - raw_spin_unlock_irqrestore(&local_storage->lock, flags); + bpf_local_storage_destroy(local_storage); bpf_cgrp_storage_unlock(); rcu_read_unlock(); - - if (free_cgroup_storage) - kfree_rcu(local_storage, rcu); } static struct bpf_local_storage_data * diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c index 05f4c66c9089..b4a9904df54e 100644 --- a/kernel/bpf/bpf_inode_storage.c +++ b/kernel/bpf/bpf_inode_storage.c @@ -57,7 +57,6 @@ static struct bpf_local_storage_data *inode_storage_lookup(struct inode *inode, void bpf_inode_storage_free(struct inode *inode) { struct bpf_local_storage *local_storage; - bool free_inode_storage = false; struct bpf_storage_blob *bsb; bsb = bpf_inode(inode); @@ -72,13 +71,8 @@ void bpf_inode_storage_free(struct inode *inode) return; } - raw_spin_lock_bh(&local_storage->lock); - free_inode_storage = bpf_local_storage_unlink_nolock(local_storage); - raw_spin_unlock_bh(&local_storage->lock); + bpf_local_storage_destroy(local_storage); rcu_read_unlock(); - - if (free_inode_storage) - kfree_rcu(local_storage, rcu); } static void *bpf_fd_inode_storage_lookup_elem(struct bpf_map *map, void *key) diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index 0510f50bd3ea..4d2bc7c97f7d 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -652,11 +652,12 @@ int bpf_local_storage_map_check_btf(const struct bpf_map *map, return 0; } -bool bpf_local_storage_unlink_nolock(struct bpf_local_storage *local_storage) +void bpf_local_storage_destroy(struct bpf_local_storage *local_storage) { struct bpf_local_storage_elem *selem; bool free_storage = false; struct hlist_node *n; + unsigned long flags; /* Neither the bpf_prog nor the bpf_map's syscall * could be modifying the local_storage->list now. @@ -667,6 +668,7 @@ bool bpf_local_storage_unlink_nolock(struct bpf_local_storage *local_storage) * when unlinking elem from the local_storage->list and * the map's bucket->list. */ + raw_spin_lock_irqsave(&local_storage->lock, flags); hlist_for_each_entry_safe(selem, n, &local_storage->list, snode) { /* Always unlink from map before unlinking from * local_storage. @@ -681,8 +683,10 @@ bool bpf_local_storage_unlink_nolock(struct bpf_local_storage *local_storage) free_storage = bpf_selem_unlink_storage_nolock( local_storage, selem, false, false); } + raw_spin_unlock_irqrestore(&local_storage->lock, flags); - return free_storage; + if (free_storage) + kfree_rcu(local_storage, rcu); } struct bpf_map * diff --git a/kernel/bpf/bpf_task_storage.c b/kernel/bpf/bpf_task_storage.c index 1e486055a523..b5f404fe146c 100644 --- a/kernel/bpf/bpf_task_storage.c +++ b/kernel/bpf/bpf_task_storage.c @@ -72,8 +72,6 @@ task_storage_lookup(struct task_struct *task, struct bpf_map *map, void bpf_task_storage_free(struct task_struct *task) { struct bpf_local_storage *local_storage; - bool free_task_storage = false; - unsigned long flags; rcu_read_lock(); @@ -84,14 +82,9 @@ void bpf_task_storage_free(struct task_struct *task) } bpf_task_storage_lock(); - raw_spin_lock_irqsave(&local_storage->lock, flags); - free_task_storage = bpf_local_storage_unlink_nolock(local_storage); - raw_spin_unlock_irqrestore(&local_storage->lock, flags); + bpf_local_storage_destroy(local_storage); bpf_task_storage_unlock(); rcu_read_unlock(); - - if (free_task_storage) - kfree_rcu(local_storage, rcu); } static void *bpf_pid_task_storage_lookup_elem(struct bpf_map *map, void *key) diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c index bb378c33f542..42569d0904a5 100644 --- a/net/core/bpf_sk_storage.c +++ b/net/core/bpf_sk_storage.c @@ -49,7 +49,6 @@ static int bpf_sk_storage_del(struct sock *sk, struct bpf_map *map) void bpf_sk_storage_free(struct sock *sk) { struct bpf_local_storage *sk_storage; - bool free_sk_storage = false; rcu_read_lock(); sk_storage = rcu_dereference(sk->sk_bpf_storage); @@ -58,13 +57,8 @@ void bpf_sk_storage_free(struct sock *sk) return; } - raw_spin_lock_bh(&sk_storage->lock); - free_sk_storage = bpf_local_storage_unlink_nolock(sk_storage); - raw_spin_unlock_bh(&sk_storage->lock); + bpf_local_storage_destroy(sk_storage); rcu_read_unlock(); - - if (free_sk_storage) - kfree_rcu(sk_storage, rcu); } static void bpf_sk_storage_map_free(struct bpf_map *map)