From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2160F23A0 for ; Thu, 22 Feb 2024 00:03:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708560180; cv=none; b=Z4rCEPU+DzyXMBpqFw6H/Iuk48Xr2cHLdMXHtdcW/Zuv7evXgSL/ekLvhDAzc7ID/czSbevMu0y+glI4FXY6CQjVQq194R7hz8n4yz4ZvQ8cfXaCNXIist7HE2xZDAZKqczm/BNvi1xijWvcVCtBop4amD5L9MWb5iZRsyzWdJc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708560180; c=relaxed/simple; bh=f4HfT/9VJamvdHGl5cRWL6lQvTrHNR0H3j26/GFqcHU=; h=Date:To:From:Subject:Message-Id; b=CHbQRS5grtZceu9q4Za2qRlTslG4w3em1unZKccBBH+UbwNhfdx6qn/T2j3ikZpj+zByjloUQQZu8G6GvXushR+ritmMj0WkfR060EHrYeQwg04Xl7SHyjSBkwij3DASW6eEOEviICxw7bGH+LRrSpLrk9Lq9mcnZL2B2S2OD8g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=1/WsWtx3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="1/WsWtx3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3F22C43390; Thu, 22 Feb 2024 00:02:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1708560180; bh=f4HfT/9VJamvdHGl5cRWL6lQvTrHNR0H3j26/GFqcHU=; h=Date:To:From:Subject:From; b=1/WsWtx3EoYw+LsSEUHNEectghpvpK18apSkSQ35EhQ4z4mTmAKqYpfWIhAjuvNlK 5EtEiI/OS22h4e22mpRbH2yhcMRzYYYAefDUz1yMZd1SHTltcWgdKzHEQlShb8mlij Zq2C/0MzAfa5gHtWYtRen/Em2VLaS8yieHezVf+g= Date: Wed, 21 Feb 2024 16:02:59 -0800 To: mm-commits@vger.kernel.org,willy@infradead.org,will@kernel.org,svens@linux.ibm.com,ryan.roberts@arm.com,rppt@kernel.org,paul.walmsley@sifive.com,palmer@dabbelt.com,npiggin@gmail.com,naveen.n.rao@linux.ibm.com,mpe@ellerman.id.au,linux@armlinux.org.uk,hca@linux.ibm.com,gor@linux.ibm.com,gerald.schaefer@linux.ibm.com,dinguyen@kernel.org,davem@davemloft.net,christophe.leroy@csgroup.eu,catalin.marinas@arm.com,borntraeger@linux.ibm.com,aou@eecs.berkeley.edu,aneesh.kumar@kernel.org,alexghiti@rivosinc.com,agordeev@linux.ibm.com,david@redhat.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-memory-ignore-writable-bit-in-folio_pte_batch.patch removed from -mm tree Message-Id: <20240222000259.E3F22C43390@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/memory: ignore writable bit in folio_pte_batch() has been removed from the -mm tree. Its filename was mm-memory-ignore-writable-bit-in-folio_pte_batch.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: David Hildenbrand Subject: mm/memory: ignore writable bit in folio_pte_batch() Date: Mon, 29 Jan 2024 13:46:49 +0100 ... and conditionally return to the caller if any PTE except the first one is writable. fork() has to make sure to properly write-protect in case any PTE is writable. Other users (e.g., page unmaping) are expected to not care. Link: https://lkml.kernel.org/r/20240129124649.189745-16-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Ryan Roberts Cc: Albert Ou Cc: Alexander Gordeev Cc: Alexandre Ghiti Cc: Aneesh Kumar K.V Cc: Catalin Marinas Cc: Christian Borntraeger Cc: Christophe Leroy Cc: David S. Miller Cc: Dinh Nguyen Cc: Gerald Schaefer Cc: Heiko Carstens Cc: Matthew Wilcox Cc: Michael Ellerman Cc: Naveen N. Rao Cc: Nicholas Piggin Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Russell King (Oracle) Cc: Sven Schnelle Cc: Vasily Gorbik Cc: Will Deacon Cc: Mike Rapoport (IBM) Signed-off-by: Andrew Morton --- mm/memory.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-) --- a/mm/memory.c~mm-memory-ignore-writable-bit-in-folio_pte_batch +++ a/mm/memory.c @@ -968,7 +968,7 @@ static inline pte_t __pte_batch_clear_ig pte = pte_mkclean(pte); if (likely(flags & FPB_IGNORE_SOFT_DIRTY)) pte = pte_clear_soft_dirty(pte); - return pte_mkold(pte); + return pte_wrprotect(pte_mkold(pte)); } /* @@ -976,21 +976,32 @@ static inline pte_t __pte_batch_clear_ig * pages of the same folio. * * All PTEs inside a PTE batch have the same PTE bits set, excluding the PFN, - * the accessed bit, dirty bit (with FPB_IGNORE_DIRTY) and soft-dirty bit - * (with FPB_IGNORE_SOFT_DIRTY). + * the accessed bit, writable bit, dirty bit (with FPB_IGNORE_DIRTY) and + * soft-dirty bit (with FPB_IGNORE_SOFT_DIRTY). + * + * If "any_writable" is set, it will indicate if any other PTE besides the + * first (given) PTE is writable. */ static inline int folio_pte_batch(struct folio *folio, unsigned long addr, - pte_t *start_ptep, pte_t pte, int max_nr, fpb_t flags) + pte_t *start_ptep, pte_t pte, int max_nr, fpb_t flags, + bool *any_writable) { unsigned long folio_end_pfn = folio_pfn(folio) + folio_nr_pages(folio); const pte_t *end_ptep = start_ptep + max_nr; pte_t expected_pte = __pte_batch_clear_ignored(pte_next_pfn(pte), flags); pte_t *ptep = start_ptep + 1; + bool writable; + + if (any_writable) + *any_writable = false; VM_WARN_ON_FOLIO(!pte_present(pte), folio); while (ptep != end_ptep) { - pte = __pte_batch_clear_ignored(ptep_get(ptep), flags); + pte = ptep_get(ptep); + if (any_writable) + writable = !!pte_write(pte); + pte = __pte_batch_clear_ignored(pte, flags); if (!pte_same(pte, expected_pte)) break; @@ -1003,6 +1014,9 @@ static inline int folio_pte_batch(struct if (pte_pfn(pte) == folio_end_pfn) break; + if (any_writable) + *any_writable |= writable; + expected_pte = pte_next_pfn(expected_pte); ptep++; } @@ -1024,6 +1038,7 @@ copy_present_ptes(struct vm_area_struct { struct page *page; struct folio *folio; + bool any_writable; fpb_t flags = 0; int err, nr; @@ -1044,7 +1059,8 @@ copy_present_ptes(struct vm_area_struct if (!vma_soft_dirty_enabled(src_vma)) flags |= FPB_IGNORE_SOFT_DIRTY; - nr = folio_pte_batch(folio, addr, src_pte, pte, max_nr, flags); + nr = folio_pte_batch(folio, addr, src_pte, pte, max_nr, flags, + &any_writable); folio_ref_add(folio, nr); if (folio_test_anon(folio)) { if (unlikely(folio_try_dup_anon_rmap_ptes(folio, page, @@ -1058,6 +1074,8 @@ copy_present_ptes(struct vm_area_struct folio_dup_file_rmap_ptes(folio, page, nr); rss[mm_counter_file(folio)] += nr; } + if (any_writable) + pte = pte_mkwrite(pte, src_vma); __copy_present_ptes(dst_vma, src_vma, dst_pte, src_pte, pte, addr, nr); return nr; _ Patches currently in -mm which might be from david@redhat.com are mm-memory-factor-out-zapping-of-present-pte-into-zap_present_pte.patch mm-memory-handle-page-case-in-zap_present_pte-separately.patch mm-memory-further-separate-anon-and-pagecache-folio-handling-in-zap_present_pte.patch mm-memory-factor-out-zapping-folio-pte-into-zap_present_folio_pte.patch mm-mmu_gather-pass-delay_rmap-instead-of-encoded-page-to-__tlb_remove_page_size.patch mm-mmu_gather-define-encoded_page_flag_delay_rmap.patch mm-mmu_gather-add-tlb_remove_tlb_entries.patch mm-mmu_gather-add-__tlb_remove_folio_pages.patch mm-mmu_gather-improve-cond_resched-handling-with-large-folios-and-expensive-page-freeing.patch mm-memory-optimize-unmap-zap-with-pte-mapped-thp.patch