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 B1A77C87FDC for ; Fri, 9 Jun 2023 20:11:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230357AbjFIULL (ORCPT ); Fri, 9 Jun 2023 16:11:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230363AbjFIULI (ORCPT ); Fri, 9 Jun 2023 16:11:08 -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 A715C3A86 for ; Fri, 9 Jun 2023 13:11:06 -0700 (PDT) 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 3B64F65B58 for ; Fri, 9 Jun 2023 20:11:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8C33BC433D2; Fri, 9 Jun 2023 20:11:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1686341465; bh=NtZfzJhf1e0dlynMOjBvluao3Wi/Ox3+qO+/OmldvZg=; h=Date:To:From:Subject:From; b=czqVuTlqyysOPHY8yCm2bJ+Ef+IjhM6mzN7elazFZ258RyyqhfYH+0559PoRlK6KB oMUejWTp8RcsVIVZbcEc16mjQxngqEgjgV951Qdm/VgdYKjLzcb0tdmYXBHjP3QoIi Wk3UHBOn1MWBThXwmwIK0kKwXMj0SYredPS44rXc= Date: Fri, 09 Jun 2023 13:11:04 -0700 To: mm-commits@vger.kernel.org, zhengqi.arch@bytedance.com, zackr@vmware.com, yuzhao@google.com, ying.huang@intel.com, willy@infradead.org, will@kernel.org, thomas.hellstrom@linux.intel.com, surenb@google.com, steven.price@arm.com, song@kernel.org, sj@kernel.org, shy828301@gmail.com, ryan.roberts@arm.com, rppt@kernel.org, rcampbell@nvidia.com, peterz@infradead.org, peterx@redhat.com, pasha.tatashin@soleen.com, naoya.horiguchi@nec.com, minchan@kernel.org, mike.kravetz@oracle.com, mgorman@techsingularity.net, lstoakes@gmail.com, linmiaohe@huawei.com, kirill.shutemov@linux.intel.com, jgg@ziepe.ca, ira.weiny@intel.com, hch@infradead.org, david@redhat.com, christophe.leroy@csgroup.eu, axelrasmussen@google.com, apopple@nvidia.com, anshuman.khandual@arm.com, hughd@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-pagewalk-walk_pte_range-allow-for-pte_offset_map.patch added to mm-unstable branch Message-Id: <20230609201105.8C33BC433D2@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: mm/pagewalk: walk_pte_range() allow for pte_offset_map() has been added to the -mm mm-unstable branch. Its filename is mm-pagewalk-walk_pte_range-allow-for-pte_offset_map.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-pagewalk-walk_pte_range-allow-for-pte_offset_map.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: Hugh Dickins Subject: mm/pagewalk: walk_pte_range() allow for pte_offset_map() Date: Thu, 8 Jun 2023 18:18:49 -0700 (PDT) walk_pte_range() has a no_vma option to serve walk_page_range_novma(). I don't know of any problem, but it looks safer to check for init_mm, and use pte_offset_kernel() rather than pte_offset_map() in that case: pte_offset_map()'s pmdval validation is intended for userspace. Allow for its pte_offset_map() or pte_offset_map_lock() to fail, and retry with ACTION_AGAIN if so. Add a second check for ACTION_AGAIN in walk_pmd_range(), to catch it after return from walk_pte_range(). Remove the pmd_trans_unstable() check after split_huge_pmd() in walk_pmd_range(): walk_pte_range() now handles those cases safely (and they must fail powerpc's is_hugepd() check). Link: https://lkml.kernel.org/r/3eba6f0-2b-fb66-6bb6-2ee8533e221@google.com Signed-off-by: Hugh Dickins Cc: Alistair Popple Cc: Anshuman Khandual Cc: Axel Rasmussen Cc: Christophe Leroy Cc: Christoph Hellwig Cc: David Hildenbrand Cc: "Huang, Ying" Cc: Ira Weiny Cc: Jason Gunthorpe Cc: Kirill A. Shutemov Cc: Lorenzo Stoakes Cc: Matthew Wilcox Cc: Mel Gorman Cc: Miaohe Lin Cc: Mike Kravetz Cc: Mike Rapoport (IBM) Cc: Minchan Kim Cc: Naoya Horiguchi Cc: Pavel Tatashin Cc: Peter Xu Cc: Peter Zijlstra Cc: Qi Zheng Cc: Ralph Campbell Cc: Ryan Roberts Cc: SeongJae Park Cc: Song Liu Cc: Steven Price Cc: Suren Baghdasaryan Cc: Thomas Hellström Cc: Will Deacon Cc: Yang Shi Cc: Yu Zhao Cc: Zack Rusin Signed-off-by: Andrew Morton --- mm/pagewalk.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) --- a/mm/pagewalk.c~mm-pagewalk-walk_pte_range-allow-for-pte_offset_map +++ a/mm/pagewalk.c @@ -46,15 +46,27 @@ static int walk_pte_range(pmd_t *pmd, un spinlock_t *ptl; if (walk->no_vma) { - pte = pte_offset_map(pmd, addr); - err = walk_pte_range_inner(pte, addr, end, walk); - pte_unmap(pte); + /* + * pte_offset_map() might apply user-specific validation. + */ + if (walk->mm == &init_mm) + pte = pte_offset_kernel(pmd, addr); + else + pte = pte_offset_map(pmd, addr); + if (pte) { + err = walk_pte_range_inner(pte, addr, end, walk); + if (walk->mm != &init_mm) + pte_unmap(pte); + } } else { pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); - err = walk_pte_range_inner(pte, addr, end, walk); - pte_unmap_unlock(pte, ptl); + if (pte) { + err = walk_pte_range_inner(pte, addr, end, walk); + pte_unmap_unlock(pte, ptl); + } } - + if (!pte) + walk->action = ACTION_AGAIN; return err; } @@ -141,11 +153,8 @@ again: !(ops->pte_entry)) continue; - if (walk->vma) { + if (walk->vma) split_huge_pmd(walk->vma, pmd, addr); - if (pmd_trans_unstable(pmd)) - goto again; - } if (is_hugepd(__hugepd(pmd_val(*pmd)))) err = walk_hugepd_range((hugepd_t *)pmd, addr, next, walk, PMD_SHIFT); @@ -153,6 +162,10 @@ again: err = walk_pte_range(pmd, addr, next, walk); if (err) break; + + if (walk->action == ACTION_AGAIN) + goto again; + } while (pmd++, addr = next, addr != end); return err; _ Patches currently in -mm which might be from hughd@google.com are arm-allow-pte_offset_map-to-fail.patch arm64-allow-pte_offset_map-to-fail.patch arm64-hugetlb-pte_alloc_huge-pte_offset_huge.patch ia64-hugetlb-pte_alloc_huge-pte_offset_huge.patch m68k-allow-pte_offset_map-to-fail.patch microblaze-allow-pte_offset_map-to-fail.patch mips-update_mmu_cache-can-replace-__update_tlb.patch mips-update_mmu_cache-can-replace-__update_tlb-fix.patch parisc-add-pte_unmap-to-balance-get_ptep.patch parisc-unmap_uncached_pte-use-pte_offset_kernel.patch parisc-hugetlb-pte_alloc_huge-pte_offset_huge.patch powerpc-kvmppc_unmap_free_pmd-pte_offset_kernel.patch powerpc-allow-pte_offset_map-to-fail.patch powerpc-hugetlb-pte_alloc_huge.patch riscv-hugetlb-pte_alloc_huge-pte_offset_huge.patch s390-allow-pte_offset_map_lock-to-fail.patch s390-gmap-use-pte_unmap_unlock-not-spin_unlock.patch sh-hugetlb-pte_alloc_huge-pte_offset_huge.patch sparc-hugetlb-pte_alloc_huge-pte_offset_huge.patch sparc-allow-pte_offset_map-to-fail.patch sparc-iounit-and-iommu-use-pte_offset_kernel.patch x86-allow-get_locked_pte-to-fail.patch x86-sme_populate_pgd-use-pte_offset_kernel.patch xtensa-add-pte_unmap-to-balance-pte_offset_map.patch mm-use-pmdp_get_lockless-without-surplus-barrier.patch mm-migrate-remove-cruft-from-migration_entry_waits.patch mm-pgtable-kmap_local_page-instead-of-kmap_atomic.patch mm-pgtable-allow-pte_offset_map-to-fail.patch mm-filemap-allow-pte_offset_map_lock-to-fail.patch mm-page_vma_mapped-delete-bogosity-in-page_vma_mapped_walk.patch mm-page_vma_mapped-reformat-map_pte-with-less-indentation.patch mm-page_vma_mapped-pte_offset_map_nolock-not-pte_lockptr.patch mm-pagewalkers-action_again-if-pte_offset_map_lock-fails.patch mm-pagewalk-walk_pte_range-allow-for-pte_offset_map.patch mm-vmwgfx-simplify-pmd-pud-mapping-dirty-helpers.patch mm-vmalloc-vmalloc_to_page-use-pte_offset_kernel.patch mm-hmm-retry-if-pte_offset_map-fails.patch mm-userfaultfd-retry-if-pte_offset_map-fails.patch mm-userfaultfd-allow-pte_offset_map_lock-to-fail.patch mm-debug_vm_pgtablepage_table_check-warn-pte-map-fails.patch mm-various-give-up-if-pte_offset_map-fails.patch mm-mprotect-delete-pmd_none_or_clear_bad_unless_trans_huge.patch mm-mremap-retry-if-either-pte_offset_map_lock-fails.patch mm-madvise-clean-up-pte_offset_map_lock-scans.patch mm-madvise-clean-up-force_shm_swapin_readahead.patch mm-swapoff-allow-pte_offset_map-to-fail.patch mm-mglru-allow-pte_offset_map_nolock-to-fail.patch mm-migrate_device-allow-pte_offset_map_lock-to-fail.patch mm-gup-remove-foll_split_pmd-use-of-pmd_trans_unstable.patch mm-huge_memory-split-huge-pmd-under-one-pte_offset_map.patch mm-khugepaged-allow-pte_offset_map-to-fail.patch mm-memory-allow-pte_offset_map-to-fail.patch mm-memory-handle_pte_fault-use-pte_offset_map_nolock.patch mm-pgtable-delete-pmd_trans_unstable-and-friends.patch mm-swap-swap_vma_readahead-do-the-pte_offset_map.patch perf-core-allow-pte_offset_map-to-fail.patch