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 27E6EC54EBE for ; Mon, 16 Jan 2023 21:38:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234282AbjAPVi1 (ORCPT ); Mon, 16 Jan 2023 16:38:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233226AbjAPVi0 (ORCPT ); Mon, 16 Jan 2023 16:38:26 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 735112B63B; Mon, 16 Jan 2023 13:38:25 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0F1EC61154; Mon, 16 Jan 2023 21:38:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 611C3C433EF; Mon, 16 Jan 2023 21:38:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1673905104; bh=lfcFSFE2VDqDOySKBz1PqbGxLZ1JH545q0AENmjmPs4=; h=Date:To:From:Subject:From; b=dWxepTAPE9L9NcBERtF6fkWR/X+4m78YsFAE2itB4SK6TeEG9MK62UVdmLv8UIhjP PD47NWgjnJ9cyUEKPwpDA0CBtCKcXkLMxyGU3evJwDm5Et3LZ+abKb1Kt2sSfRwftn oBn+znTkUgTi4lGc/SX5OI0MMk6ZarkRLXE/wD80= Date: Mon, 16 Jan 2023 13:38:23 -0800 To: mm-commits@vger.kernel.org, stable@vger.kernel.org, msizanoen@qtmlabs.xyz, yuzhao@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-multi-gen-lru-fix-crash-during-cgroup-migration.patch added to mm-hotfixes-unstable branch Message-Id: <20230116213824.611C3C433EF@smtp.kernel.org> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch titled Subject: mm: multi-gen LRU: fix crash during cgroup migration has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-multi-gen-lru-fix-crash-during-cgroup-migration.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-multi-gen-lru-fix-crash-during-cgroup-migration.patch This patch will later appear in the mm-hotfixes-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: Yu Zhao Subject: mm: multi-gen LRU: fix crash during cgroup migration Date: Sun, 15 Jan 2023 20:44:05 -0700 lru_gen_migrate_mm() assumes lru_gen_add_mm() runs prior to itself. This isn't true for the following scenario: CPU 1 CPU 2 clone() cgroup_can_fork() cgroup_procs_write() cgroup_post_fork() task_lock() lru_gen_migrate_mm() task_unlock() task_lock() lru_gen_add_mm() task_unlock() And when the above happens, kernel crashes because of linked list corruption (mm_struct->lru_gen.list). Link: https://lore.kernel.org/r/20230115134651.30028-1-msizanoen@qtmlabs.xyz/ Link: https://lkml.kernel.org/r/20230116034405.2960276-1-yuzhao@google.com Fixes: bd74fdaea146 ("mm: multi-gen LRU: support page table walks") Signed-off-by: Yu Zhao Reported-by: msizanoen Tested-by: msizanoen Cc: [6.1+] Signed-off-by: Andrew Morton --- --- a/mm/vmscan.c~mm-multi-gen-lru-fix-crash-during-cgroup-migration +++ a/mm/vmscan.c @@ -3323,13 +3323,16 @@ void lru_gen_migrate_mm(struct mm_struct if (mem_cgroup_disabled()) return; + /* migration can happen before addition */ + if (!mm->lru_gen.memcg) + return; + rcu_read_lock(); memcg = mem_cgroup_from_task(task); rcu_read_unlock(); if (memcg == mm->lru_gen.memcg) return; - VM_WARN_ON_ONCE(!mm->lru_gen.memcg); VM_WARN_ON_ONCE(list_empty(&mm->lru_gen.list)); lru_gen_del_mm(mm); _ Patches currently in -mm which might be from yuzhao@google.com are mm-multi-gen-lru-fix-crash-during-cgroup-migration.patch mm-multi-gen-lru-rename-lru_gen_struct-to-lru_gen_folio.patch mm-multi-gen-lru-rename-lrugen-lists-to-lrugen-folios.patch mm-multi-gen-lru-remove-eviction-fairness-safeguard.patch mm-multi-gen-lru-remove-aging-fairness-safeguard.patch mm-multi-gen-lru-shuffle-should_run_aging.patch mm-multi-gen-lru-per-node-lru_gen_folio-lists.patch mm-multi-gen-lru-clarify-scan_control-flags.patch mm-multi-gen-lru-simplify-arch_has_hw_pte_young-check.patch mm-add-vma_has_recency.patch mm-support-posix_fadv_noreuse.patch