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 153C7C0015E for ; Wed, 19 Jul 2023 19:21:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230490AbjGSTVr (ORCPT ); Wed, 19 Jul 2023 15:21:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231234AbjGSTVf (ORCPT ); Wed, 19 Jul 2023 15:21:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3E10D1FC0 for ; Wed, 19 Jul 2023 12:21:22 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4A1D6617E9 for ; Wed, 19 Jul 2023 19:21:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2DE6C433C7; Wed, 19 Jul 2023 19:21:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1689794481; bh=3wO5QeyQl4RyJP04Q26lc3ulvi+DEecy4rgFb03Vl6o=; h=Date:To:From:Subject:From; b=KV0o81XIBcuU3eAKYqUlTTRI7or3hZyNcCWGcohiWG2k+Nritb2G1Lkyzr1Okh0o9 tDNoU/MRQN4tmt2lf/eMFHgn0T2rwpDWkRH0GG3zWiN2eX93lZ/fA5av6tnI/2AVk+ h/H3JF+G1rZOYAhrC5hhzdwXIR0wbNwD7w9bQvEA= Date: Wed, 19 Jul 2023 12:21:21 -0700 To: mm-commits@vger.kernel.org, torvalds@linux-foundation.org, oliver.sang@intel.com, Liam.Howlett@oracle.com, akpm@linux-foundation.org From: Andrew Morton Subject: + maple_tree-be-more-strict-about-locking.patch added to mm-unstable branch Message-Id: <20230719192121.A2DE6C433C7@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: maple_tree: Be more strict about locking has been added to the -mm mm-unstable branch. Its filename is maple_tree-be-more-strict-about-locking.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-be-more-strict-about-locking.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Liam R. Howlett" Subject: maple_tree: Be more strict about locking Date: Fri, 14 Jul 2023 15:55:51 -0400 Use lockdep to check the write path in the maple tree holds the lock in write mode. Introduce mt_write_lock_is_held() to check if the lock is held for writing. Update the necessary checks for rcu_dereference_protected() to use the new write lock check. Link: https://lkml.kernel.org/r/20230714195551.894800-5-Liam.Howlett@oracle.com Cc: Linus Torvalds Signed-off-by: Liam R. Howlett Cc: Oliver Sang Signed-off-by: Andrew Morton --- include/linux/maple_tree.h | 7 ++++++- lib/maple_tree.c | 10 ++++++++-- 2 files changed, 14 insertions(+), 3 deletions(-) --- a/include/linux/maple_tree.h~maple_tree-be-more-strict-about-locking +++ a/include/linux/maple_tree.h @@ -185,13 +185,18 @@ typedef struct lockdep_map *lockdep_map_ #define mt_lock_is_held(mt) \ (!(mt)->ma_external_lock || lock_is_held((mt)->ma_external_lock)) +#define mt_write_lock_is_held(mt) \ + (!(mt)->ma_external_lock || \ + lock_is_held_type((mt)->ma_external_lock, 0)) + #define mt_set_external_lock(mt, lock) \ (mt)->ma_external_lock = &(lock)->dep_map #define mt_on_stack(mt) (mt).ma_external_lock = NULL #else typedef struct { /* nothing */ } lockdep_map_p; -#define mt_lock_is_held(mt) 1 +#define mt_lock_is_held(mt) 1 +#define mt_write_lock_is_held(mt) 1 #define mt_set_external_lock(mt, lock) do { } while (0) #define mt_on_stack(mt) do { } while (0) #endif --- a/lib/maple_tree.c~maple_tree-be-more-strict-about-locking +++ a/lib/maple_tree.c @@ -777,6 +777,12 @@ static inline void __rcu **ma_slots(stru } } +static inline bool mt_write_locked(const struct maple_tree *mt) +{ + return mt_external_lock(mt) ? mt_write_lock_is_held(mt) : + lockdep_is_held(&mt->ma_lock); +} + static inline bool mt_locked(const struct maple_tree *mt) { return mt_external_lock(mt) ? mt_lock_is_held(mt) : @@ -792,7 +798,7 @@ static inline void *mt_slot(const struct static inline void *mt_slot_locked(struct maple_tree *mt, void __rcu **slots, unsigned char offset) { - return rcu_dereference_protected(slots[offset], mt_locked(mt)); + return rcu_dereference_protected(slots[offset], mt_write_locked(mt)); } /* * mas_slot_locked() - Get the slot value when holding the maple tree lock. @@ -835,7 +841,7 @@ static inline void *mas_root(struct ma_s static inline void *mt_root_locked(struct maple_tree *mt) { - return rcu_dereference_protected(mt->ma_root, mt_locked(mt)); + return rcu_dereference_protected(mt->ma_root, mt_write_locked(mt)); } /* _ Patches currently in -mm which might be from Liam.Howlett@oracle.com are mm-mmap-clean-up-validate_mm-calls.patch maple_tree-relax-lockdep-checks-for-on-stack-trees.patch mm-mmap-change-detached-vma-locking-scheme.patch maple_tree-be-more-strict-about-locking.patch