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 37433C433EF for ; Mon, 28 Mar 2022 22:39:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230138AbiC1Wl0 (ORCPT ); Mon, 28 Mar 2022 18:41:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230091AbiC1WlP (ORCPT ); Mon, 28 Mar 2022 18:41:15 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 825B94A910 for ; Mon, 28 Mar 2022 15:39:32 -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 sin.source.kernel.org (Postfix) with ESMTPS id CB5C1CE1767 for ; Mon, 28 Mar 2022 22:39:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E684C340EC; Mon, 28 Mar 2022 22:39:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1648507169; bh=33e4jeP4hD6/3z6LsciUPRFfukpuzreIkCbysXMxXJA=; h=Date:To:From:Subject:From; b=EHQo0uxXSKi4xRPdLnXH1EQV86f46D7RAvbd8eBktwATgjuw/j/TXMVAYs/LaBO/j sGl6uizbxDs1vXGo840fEwOkDA+RwbTMoWy52SV83/xb6g7ZMthYFFDvi2W2IGkfrn 3vYkzOHS7Hz/aRUwS1FPrQ/cvGLNYC9wkBv/Jg68= Date: Mon, 28 Mar 2022 15:39:28 -0700 To: mm-commits@vger.kernel.org, zwisler@kernel.org, xiyuyang19@fudan.edu.cn, willy@infradead.org, viro@zeniv.linux.org.uk, shy828301@gmail.com, rcampbell@nvidia.com, kirill.shutemov@linux.intel.com, jack@suse.cz, hughd@google.com, hch@lst.de, duanxiongchun@bytedance.com, dan.j.williams@intel.com, apopple@nvidia.com, songmuchun@bytedance.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-simplify-follow_invalidate_pte.patch added to -mm tree Message-Id: <20220328223929.2E684C340EC@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: simplify follow_invalidate_pte() has been added to the -mm tree. Its filename is mm-simplify-follow_invalidate_pte.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-simplify-follow_invalidate_pte.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-simplify-follow_invalidate_pte.patch 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 and is updated there every 3-4 working days ------------------------------------------------------ From: Muchun Song Subject: mm: simplify follow_invalidate_pte() The only user (DAX) of range and pmdpp parameters of follow_invalidate_pte() is gone, it is safe to remove them and make it static to simlify the code. This is revertant of the following commits: 097963959594 ("mm: add follow_pte_pmd()") a4d1a8852513 ("dax: update to new mmu_notifier semantic") There is only one caller of the follow_invalidate_pte(). So just fold it into follow_pte() and remove it. Link: https://lkml.kernel.org/r/20220318074529.5261-7-songmuchun@bytedance.com Signed-off-by: Muchun Song Cc: Alistair Popple Cc: Al Viro Cc: Christoph Hellwig Cc: Dan Williams Cc: Hugh Dickins Cc: Jan Kara Cc: "Kirill A. Shutemov" Cc: Matthew Wilcox Cc: Ralph Campbell Cc: Ross Zwisler Cc: Xiongchun Duan Cc: Xiyu Yang Cc: Yang Shi Signed-off-by: Andrew Morton --- include/linux/mm.h | 3 - mm/memory.c | 81 ++++++++++++------------------------------- 2 files changed, 23 insertions(+), 61 deletions(-) --- a/include/linux/mm.h~mm-simplify-follow_invalidate_pte +++ a/include/linux/mm.h @@ -1845,9 +1845,6 @@ void free_pgd_range(struct mmu_gather *t unsigned long end, unsigned long floor, unsigned long ceiling); int copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma); -int follow_invalidate_pte(struct mm_struct *mm, unsigned long address, - struct mmu_notifier_range *range, pte_t **ptepp, - pmd_t **pmdpp, spinlock_t **ptlp); int follow_pte(struct mm_struct *mm, unsigned long address, pte_t **ptepp, spinlock_t **ptlp); int follow_pfn(struct vm_area_struct *vma, unsigned long address, --- a/mm/memory.c~mm-simplify-follow_invalidate_pte +++ a/mm/memory.c @@ -4949,9 +4949,29 @@ int __pmd_alloc(struct mm_struct *mm, pu } #endif /* __PAGETABLE_PMD_FOLDED */ -int follow_invalidate_pte(struct mm_struct *mm, unsigned long address, - struct mmu_notifier_range *range, pte_t **ptepp, - pmd_t **pmdpp, spinlock_t **ptlp) +/** + * follow_pte - look up PTE at a user virtual address + * @mm: the mm_struct of the target address space + * @address: user virtual address + * @ptepp: location to store found PTE + * @ptlp: location to store the lock for the PTE + * + * On a successful return, the pointer to the PTE is stored in @ptepp; + * the corresponding lock is taken and its location is stored in @ptlp. + * The contents of the PTE are only stable until @ptlp is released; + * any further use, if any, must be protected against invalidation + * with MMU notifiers. + * + * Only IO mappings and raw PFN mappings are allowed. The mmap semaphore + * should be taken for read. + * + * KVM uses this function. While it is arguably less bad than ``follow_pfn``, + * it is not a good general-purpose API. + * + * Return: zero on success, -ve otherwise. + */ +int follow_pte(struct mm_struct *mm, unsigned long address, + pte_t **ptepp, spinlock_t **ptlp) { pgd_t *pgd; p4d_t *p4d; @@ -4974,35 +4994,9 @@ int follow_invalidate_pte(struct mm_stru pmd = pmd_offset(pud, address); VM_BUG_ON(pmd_trans_huge(*pmd)); - if (pmd_huge(*pmd)) { - if (!pmdpp) - goto out; - - if (range) { - mmu_notifier_range_init(range, MMU_NOTIFY_CLEAR, 0, - NULL, mm, address & PMD_MASK, - (address & PMD_MASK) + PMD_SIZE); - mmu_notifier_invalidate_range_start(range); - } - *ptlp = pmd_lock(mm, pmd); - if (pmd_huge(*pmd)) { - *pmdpp = pmd; - return 0; - } - spin_unlock(*ptlp); - if (range) - mmu_notifier_invalidate_range_end(range); - } - if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) goto out; - if (range) { - mmu_notifier_range_init(range, MMU_NOTIFY_CLEAR, 0, NULL, mm, - address & PAGE_MASK, - (address & PAGE_MASK) + PAGE_SIZE); - mmu_notifier_invalidate_range_start(range); - } ptep = pte_offset_map_lock(mm, pmd, address, ptlp); if (!pte_present(*ptep)) goto unlock; @@ -5010,38 +5004,9 @@ int follow_invalidate_pte(struct mm_stru return 0; unlock: pte_unmap_unlock(ptep, *ptlp); - if (range) - mmu_notifier_invalidate_range_end(range); out: return -EINVAL; } - -/** - * follow_pte - look up PTE at a user virtual address - * @mm: the mm_struct of the target address space - * @address: user virtual address - * @ptepp: location to store found PTE - * @ptlp: location to store the lock for the PTE - * - * On a successful return, the pointer to the PTE is stored in @ptepp; - * the corresponding lock is taken and its location is stored in @ptlp. - * The contents of the PTE are only stable until @ptlp is released; - * any further use, if any, must be protected against invalidation - * with MMU notifiers. - * - * Only IO mappings and raw PFN mappings are allowed. The mmap semaphore - * should be taken for read. - * - * KVM uses this function. While it is arguably less bad than ``follow_pfn``, - * it is not a good general-purpose API. - * - * Return: zero on success, -ve otherwise. - */ -int follow_pte(struct mm_struct *mm, unsigned long address, - pte_t **ptepp, spinlock_t **ptlp) -{ - return follow_invalidate_pte(mm, address, NULL, ptepp, NULL, ptlp); -} EXPORT_SYMBOL_GPL(follow_pte); /** _ Patches currently in -mm which might be from songmuchun@bytedance.com are mm-kfence-fix-objcgs-vector-allocation.patch mm-rmap-fix-cache-flush-on-thp-pages.patch dax-fix-cache-flush-on-pmd-mapped-pages.patch mm-rmap-introduce-pfn_mkclean_range-to-cleans-ptes.patch mm-pvmw-add-support-for-walking-devmap-pages.patch dax-fix-missing-writeprotect-the-pte-entry.patch mm-simplify-follow_invalidate_pte.patch