From patchwork Fri Mar 28 09:13:38 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Gordeev X-Patchwork-Id: 14031781 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9ED55C36016 for ; Fri, 28 Mar 2025 09:14:07 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.930364.1333017 (Exim 4.92) (envelope-from ) id 1ty5mm-00022U-IX; Fri, 28 Mar 2025 09:13:56 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 930364.1333017; Fri, 28 Mar 2025 09:13:56 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ty5mm-00022N-FV; Fri, 28 Mar 2025 09:13:56 +0000 Received: by outflank-mailman (input) for mailman id 930364; Fri, 28 Mar 2025 09:13:54 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ty5mk-0001o1-F3 for xen-devel@lists.xenproject.org; Fri, 28 Mar 2025 09:13:54 +0000 Received: from li-008a6a4c-3549-11b2-a85c-c5cc2836eea2.ibm.com (unknown [2a02:8070:a484:e780::f9cd]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id f6e79dad-0bb4-11f0-9ffa-bf95429c2676; Fri, 28 Mar 2025 10:13:52 +0100 (CET) Received: from agordeev by li-008a6a4c-3549-11b2-a85c-c5cc2836eea2.ibm.com with local (Exim 4.98.1) (envelope-from ) id 1ty5mY-00000001t9d-1CLF; Fri, 28 Mar 2025 10:13:42 +0100 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list X-Inumbo-ID: f6e79dad-0bb4-11f0-9ffa-bf95429c2676 From: Alexander Gordeev To: Andrey Ryabinin , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, kasan-dev@googlegroups.com, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, Hugh Dickins , Nicholas Piggin , Guenter Roeck , Juergen Gross , Jeremy Fitzhardinge Subject: [PATCH 0/4] mm: Fix apply_to_pte_range() vs lazy MMU mode Date: Fri, 28 Mar 2025 10:13:38 +0100 Message-ID: X-Mailer: git-send-email 2.43.5 MIME-Version: 1.0 Sender: Alexander Gordeev Hi All! On s390 if make arch_enter_lazy_mmu_mode() do preempt_enable() and arch_leave_lazy_mmu_mode() do preempt_disable() I am getting this: [ 553.332108] preempt_count: 1, expected: 0 [ 553.332117] no locks held by multipathd/2116. [ 553.332128] CPU: 24 PID: 2116 Comm: multipathd Kdump: loaded Tainted: [ 553.332139] Hardware name: IBM 3931 A01 701 (LPAR) [ 553.332146] Call Trace: [ 553.332152] [<00000000158de23a>] dump_stack_lvl+0xfa/0x150 [ 553.332167] [<0000000013e10d12>] __might_resched+0x57a/0x5e8 [ 553.332178] [<00000000144eb6c2>] __alloc_pages+0x2ba/0x7c0 [ 553.332189] [<00000000144d5cdc>] __get_free_pages+0x2c/0x88 [ 553.332198] [<00000000145663f6>] kasan_populate_vmalloc_pte+0x4e/0x110 [ 553.332207] [<000000001447625c>] apply_to_pte_range+0x164/0x3c8 [ 553.332218] [<000000001448125a>] apply_to_pmd_range+0xda/0x318 [ 553.332226] [<000000001448181c>] __apply_to_page_range+0x384/0x768 [ 553.332233] [<0000000014481c28>] apply_to_page_range+0x28/0x38 [ 553.332241] [<00000000145665da>] kasan_populate_vmalloc+0x82/0x98 [ 553.332249] [<00000000144c88d0>] alloc_vmap_area+0x590/0x1c90 [ 553.332257] [<00000000144ca108>] __get_vm_area_node.constprop.0+0x138/0x260 [ 553.332265] [<00000000144d17fc>] __vmalloc_node_range+0x134/0x360 [ 553.332274] [<0000000013d5dbf2>] alloc_thread_stack_node+0x112/0x378 [ 553.332284] [<0000000013d62726>] dup_task_struct+0x66/0x430 [ 553.332293] [<0000000013d63962>] copy_process+0x432/0x4b80 [ 553.332302] [<0000000013d68300>] kernel_clone+0xf0/0x7d0 [ 553.332311] [<0000000013d68bd6>] __do_sys_clone+0xae/0xc8 [ 553.332400] [<0000000013d68dee>] __s390x_sys_clone+0xd6/0x118 [ 553.332410] [<0000000013c9d34c>] do_syscall+0x22c/0x328 [ 553.332419] [<00000000158e7366>] __do_syscall+0xce/0xf0 [ 553.332428] [<0000000015913260>] system_call+0x70/0x98 I guess, commit b9ef323ea168 ("powerpc/64s: Disable preemption in hash lazy mmu mode") (albeit not completely) fixed similar issue on PPC: apply_to_page_range on kernel pages does not disable preemption, which is a requirement for hash's lazy mmu mode, which keeps track of the TLBs to flush with a per-cpu array. This series is an attempt to fix the violation of lazy MMU mode context as described for arch_enter_lazy_mmu_mode(): This mode can only be entered and left under the protection of the page table locks for all page tables which may be modified. If I am not mistaken, xen and sparc are also prone to the described problem, as they use this_cpu_ptr() rather than get_cpu_var(). Take init_mm.page_table_lock for kernel tables to avoid all of that. Thanks! Alexander Gordeev (4): kasan: Avoid sleepable page allocation from atomic context mm: Allow detection of wrong arch_enter_lazy_mmu_mode() context mm: Cleanup apply_to_pte_range() routine mm: Protect kernel pgtables in apply_to_pte_range() include/linux/pgtable.h | 15 ++++++++++++--- mm/kasan/shadow.c | 9 +++------ mm/memory.c | 33 +++++++++++++++++++++------------ 3 files changed, 36 insertions(+), 21 deletions(-)