From mboxrd@z Thu Jan 1 00:00:00 1970 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 95E17C636CC for ; Thu, 16 Feb 2023 05:18:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229603AbjBPFSR (ORCPT ); Thu, 16 Feb 2023 00:18:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229564AbjBPFSE (ORCPT ); Thu, 16 Feb 2023 00:18:04 -0500 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65E1F1F5C0 for ; Wed, 15 Feb 2023 21:18:02 -0800 (PST) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-4cddba76f55so8292917b3.23 for ; Wed, 15 Feb 2023 21:18:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=UHRaAOWRO45il7vCWYolP2vMSHNJY77rtpcEDPLreFo=; b=JaAJMQvkQYkAsRG/T0d+zxwkrl7mq+q9FZsokrXfiBXR+R1ZXxx2vVNR2lMSqf4OC/ WN5L5m6K8l41JtRKI2HZbVfjAY+cjnkF1BJGHx4Vp8UHSVK5UGOhTfSvkmRDjsxq+IrD 02V2mM9EdjYNQiXsOwUhDaiCYn5z8ljJQUJeFnF2XY5CF0WF7YFz2opQhOGyVfb59slI zMkZhBxatB6Jt2s9icMmk1QAWL7dqweRI7j0fEknZ3XaTRcFBLrS6UTE7S7Q4BJqI8Vo VXsm9/T42jqn+e5iri473tsxrbcsgusYZ9oNJzgxHuxj6F/D7b6ACgioO/upEa2Rro7t uyJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=UHRaAOWRO45il7vCWYolP2vMSHNJY77rtpcEDPLreFo=; b=SOijBJvIgOce2EFpNxMyERObgQe9m95TBLQ3pu3qLQXq4wpVCekgjTIMl8Ms850+g2 4lWxnk5yS0+fjV3e9810Yd6Ts7tpOHDuEMgNqrmIx+lFTZ8sawLVux8voJaE8KKrNRVv KWseAChGtAGOz+ulNKYCparpik2ga98nYeZun9wqAlH4ZG7ZhZkiIKlOwT2MaeE2pT0d W2qcMk6JV59pd9oh73knnPj5uPksFNeZ2wnURbjui5B+GfKEbwaVzdrwhOoz6AJDtNlf Msx5YQZhA1WhsgZJnZgOhCi0+ntzImMpesG5a+ulpxa8Yy5l8SUC05WJVk6lvHGLgZcz ACBg== X-Gm-Message-State: AO0yUKUrqKRPpC21ArbpoqtVF4/DpUAZPkeRTxKyrKoWGGEZV1z9JRmQ J/s56K0pz8c0E7mGydiuxLiuoBBv/Q4= X-Google-Smtp-Source: AK7set8Uq/nZgRLZFfJuxWYQ4ij1Dw1PY56gBuOAhM9aSZ73J6nsbhc6qz5TmHaa+yP435YL3FPEkHcMzr0= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:200:f781:d5ed:1806:6ebb]) (user=surenb job=sendgmr) by 2002:a05:6902:10f:b0:855:fa17:4f5f with SMTP id o15-20020a056902010f00b00855fa174f5fmr80ybh.1.1676524681354; Wed, 15 Feb 2023 21:18:01 -0800 (PST) Date: Wed, 15 Feb 2023 21:17:18 -0800 In-Reply-To: <20230216051750.3125598-1-surenb@google.com> Mime-Version: 1.0 References: <20230216051750.3125598-1-surenb@google.com> X-Mailer: git-send-email 2.39.1.581.gbfd45094c4-goog Message-ID: <20230216051750.3125598-4-surenb@google.com> Subject: [PATCH v3 03/35] maple_tree: Fix freeing of nodes in rcu mode From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: michel@lespinasse.org, jglisse@google.com, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, paulmck@kernel.org, mingo@redhat.com, will@kernel.org, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, punit.agrawal@bytedance.com, lstoakes@gmail.com, peterjung1337@gmail.com, rientjes@google.com, chriscli@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, rppt@kernel.org, jannh@google.com, shakeelb@google.com, tatashin@google.com, edumazet@google.com, gthelen@google.com, gurua@google.com, arjunroy@google.com, soheil@google.com, leewalsh@google.com, posk@google.com, michalechner92@googlemail.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com, Liam Howlett , Suren Baghdasaryan Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Liam Howlett The walk to destroy the nodes was not always setting the node type and would result in a destroy method potentially using the values as nodes. Avoid this by setting the correct node types. This is necessary for the RCU mode of the maple tree. Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Liam Howlett Signed-off-by: Suren Baghdasaryan --- lib/maple_tree.c | 73 ++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 62 insertions(+), 11 deletions(-) diff --git a/lib/maple_tree.c b/lib/maple_tree.c index 089cd76ec379..44d6ce30b28e 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -902,6 +902,44 @@ static inline void ma_set_meta(struct maple_node *mn, enum maple_type mt, meta->end = end; } +/* + * mas_clear_meta() - clear the metadata information of a node, if it exists + * @mas: The maple state + * @mn: The maple node + * @mt: The maple node type + * @offset: The offset of the highest sub-gap in this node. + * @end: The end of the data in this node. + */ +static inline void mas_clear_meta(struct ma_state *mas, struct maple_node *mn, + enum maple_type mt) +{ + struct maple_metadata *meta; + unsigned long *pivots; + void __rcu **slots; + void *next; + + switch (mt) { + case maple_range_64: + pivots = mn->mr64.pivot; + if (unlikely(pivots[MAPLE_RANGE64_SLOTS - 2])) { + slots = mn->mr64.slot; + next = mas_slot_locked(mas, slots, + MAPLE_RANGE64_SLOTS - 1); + if (unlikely((mte_to_node(next) && mte_node_type(next)))) + return; /* The last slot is a node, no metadata */ + } + fallthrough; + case maple_arange_64: + meta = ma_meta(mn, mt); + break; + default: + return; + } + + meta->gap = 0; + meta->end = 0; +} + /* * ma_meta_end() - Get the data end of a node from the metadata * @mn: The maple node @@ -5455,20 +5493,22 @@ static inline int mas_rev_alloc(struct ma_state *mas, unsigned long min, * mas_dead_leaves() - Mark all leaves of a node as dead. * @mas: The maple state * @slots: Pointer to the slot array + * @type: The maple node type * * Must hold the write lock. * * Return: The number of leaves marked as dead. */ static inline -unsigned char mas_dead_leaves(struct ma_state *mas, void __rcu **slots) +unsigned char mas_dead_leaves(struct ma_state *mas, void __rcu **slots, + enum maple_type mt) { struct maple_node *node; enum maple_type type; void *entry; int offset; - for (offset = 0; offset < mt_slot_count(mas->node); offset++) { + for (offset = 0; offset < mt_slots[mt]; offset++) { entry = mas_slot_locked(mas, slots, offset); type = mte_node_type(entry); node = mte_to_node(entry); @@ -5487,14 +5527,13 @@ unsigned char mas_dead_leaves(struct ma_state *mas, void __rcu **slots) static void __rcu **mas_dead_walk(struct ma_state *mas, unsigned char offset) { - struct maple_node *node, *next; + struct maple_node *next; void __rcu **slots = NULL; next = mas_mn(mas); do { - mas->node = ma_enode_ptr(next); - node = mas_mn(mas); - slots = ma_slots(node, node->type); + mas->node = mt_mk_node(next, next->type); + slots = ma_slots(next, next->type); next = mas_slot_locked(mas, slots, offset); offset = 0; } while (!ma_is_leaf(next->type)); @@ -5558,11 +5597,14 @@ static inline void __rcu **mas_destroy_descend(struct ma_state *mas, node = mas_mn(mas); slots = ma_slots(node, mte_node_type(mas->node)); next = mas_slot_locked(mas, slots, 0); - if ((mte_dead_node(next))) + if ((mte_dead_node(next))) { + mte_to_node(next)->type = mte_node_type(next); next = mas_slot_locked(mas, slots, 1); + } mte_set_node_dead(mas->node); node->type = mte_node_type(mas->node); + mas_clear_meta(mas, node, node->type); node->piv_parent = prev; node->parent_slot = offset; offset = 0; @@ -5582,13 +5624,18 @@ static void mt_destroy_walk(struct maple_enode *enode, unsigned char ma_flags, MA_STATE(mas, &mt, 0, 0); - if (mte_is_leaf(enode)) + mas.node = enode; + if (mte_is_leaf(enode)) { + node->type = mte_node_type(enode); goto free_leaf; + } + ma_flags &= ~MT_FLAGS_LOCK_MASK; mt_init_flags(&mt, ma_flags); mas_lock(&mas); - mas.node = start = enode; + mte_to_node(enode)->ma_flags = ma_flags; + start = enode; slots = mas_destroy_descend(&mas, start, 0); node = mas_mn(&mas); do { @@ -5596,7 +5643,8 @@ static void mt_destroy_walk(struct maple_enode *enode, unsigned char ma_flags, unsigned char offset; struct maple_enode *parent, *tmp; - node->slot_len = mas_dead_leaves(&mas, slots); + node->type = mte_node_type(mas.node); + node->slot_len = mas_dead_leaves(&mas, slots, node->type); if (free) mt_free_bulk(node->slot_len, slots); offset = node->parent_slot + 1; @@ -5620,7 +5668,8 @@ static void mt_destroy_walk(struct maple_enode *enode, unsigned char ma_flags, } while (start != mas.node); node = mas_mn(&mas); - node->slot_len = mas_dead_leaves(&mas, slots); + node->type = mte_node_type(mas.node); + node->slot_len = mas_dead_leaves(&mas, slots, node->type); if (free) mt_free_bulk(node->slot_len, slots); @@ -5630,6 +5679,8 @@ static void mt_destroy_walk(struct maple_enode *enode, unsigned char ma_flags, free_leaf: if (free) mt_free_rcu(&node->rcu); + else + mas_clear_meta(&mas, node, node->type); } /* -- 2.39.1