From f90a77c547f35c8948b90da62c465c8ef77cf3ed Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Fri, 16 Sep 2022 21:06:33 +0800 Subject: [PATCH 01/13] mm: change page type prior to adding page table entry mainline inclusion from mainline-v6.0 commit 1eba86c096e35e3cc83de1ad2c26f2d70470211b category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1eba86c096e35e3cc83de1ad2c26f2d70470211b ------------------------------------------------- Patch series "page table check", v3. Ensure that some memory corruptions are prevented by checking at the time of insertion of entries into user page tables that there is no illegal sharing. We have recently found a problem [1] that existed in kernel since 4.14. The problem was caused by broken page ref count and led to memory leaking from one process into another. The problem was accidentally detected by studying a dump of one process and noticing that one page contains memory that should not belong to this process. There are some other page->_refcount related problems that were recently fixed: [2], [3] which potentially could also lead to illegal sharing. In addition to hardening refcount [4] itself, this work is an attempt to prevent this class of memory corruption issues. It uses a simple state machine that is independent from regular MM logic to check for illegal sharing at time pages are inserted and removed from page tables. [1] https://lore.kernel.org/all/xr9335nxwc5y.fsf@gthelen2.svl.corp.google.com [2] https://lore.kernel.org/all/1582661774-30925-2-git-send-email-akaher@vmware.com [3] https://lore.kernel.org/all/20210622021423.154662-3-mike.kravetz@oracle.com [4] https://lore.kernel.org/all/20211221150140.988298-1-pasha.tatashin@soleen.com This patch (of 4): There are a few places where we first update the entry in the user page table, and later change the struct page to indicate that this is anonymous or file page. In most places, however, we first configure the page metadata and then insert entries into the page table. Page table check, will use the information from struct page to verify the type of entry is inserted. Change the order in all places to first update struct page, and later to update page table. This means that we first do calls that may change the type of page (anon or file): page_move_anon_rmap page_add_anon_rmap do_page_add_anon_rmap page_add_new_anon_rmap page_add_file_rmap hugepage_add_anon_rmap hugepage_add_new_anon_rmap And after that do calls that add entries to the page table: set_huge_pte_at set_pte_at Link: https://lkml.kernel.org/r/20211221154650.1047963-1-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20211221154650.1047963-2-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin Cc: David Rientjes Cc: Paul Turner Cc: Wei Xu Cc: Greg Thelen Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Will Deacon Cc: Mike Rapoport Cc: Kees Cook Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Masahiro Yamada Cc: Sami Tolvanen Cc: Dave Hansen Cc: Frederic Weisbecker Cc: "H. Peter Anvin" Cc: Aneesh Kumar K.V Cc: Jiri Slaby Cc: Muchun Song Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Zeng Zhimin --- mm/hugetlb.c | 4 ++-- mm/memory.c | 5 +++-- mm/migrate.c | 5 ++--- mm/swapfile.c | 4 ++-- 4 files changed, 9 insertions(+), 9 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 1985d8a7a57d..ad807d65d815 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4693,10 +4693,10 @@ static vm_fault_t hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, /* Break COW */ huge_ptep_clear_flush(vma, haddr, ptep); mmu_notifier_invalidate_range(mm, range.start, range.end); - set_huge_pte_at(mm, haddr, ptep, - make_huge_pte(vma, new_page, 1)); page_remove_rmap(old_page, true); hugepage_add_new_anon_rmap(new_page, vma, haddr); + set_huge_pte_at(mm, haddr, ptep, + make_huge_pte(vma, new_page, 1)); SetHPageMigratable(new_page); /* Make the old page be freed below */ new_page = old_page; diff --git a/mm/memory.c b/mm/memory.c index f1d28ad88944..133deca67429 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3537,8 +3537,6 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) pte = pte_mkuffd_wp(pte); pte = pte_wrprotect(pte); } - set_pte_at(vma->vm_mm, vmf->address, vmf->pte, pte); - arch_do_swap_page(vma->vm_mm, vma, vmf->address, pte, vmf->orig_pte); vmf->orig_pte = pte; /* ksm created a completely new copy */ @@ -3549,6 +3547,9 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) do_page_add_anon_rmap(page, vma, vmf->address, exclusive); } + set_pte_at(vma->vm_mm, vmf->address, vmf->pte, pte); + arch_do_swap_page(vma->vm_mm, vma, vmf->address, pte, vmf->orig_pte); + swap_free(entry); if (mem_cgroup_swap_full(page) || (vma->vm_flags & VM_LOCKED) || PageMlocked(page)) diff --git a/mm/migrate.c b/mm/migrate.c index 1f78410a1063..ba6cb49e1ab4 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -259,21 +259,20 @@ static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma, if (PageHuge(new)) { pte = pte_mkhuge(pte); pte = arch_make_huge_pte(pte, vma, new, 0); - set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte); if (PageAnon(new)) hugepage_add_anon_rmap(new, vma, pvmw.address); else page_dup_rmap(new, true); + set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte); } else #endif { - set_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte); - reliable_page_counter(new, vma->vm_mm, 1); if (PageAnon(new)) page_add_anon_rmap(new, vma, pvmw.address, false); else page_add_file_rmap(new, false); + set_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte); } if (vma->vm_flags & VM_LOCKED && !PageTransCompound(new)) mlock_vma_page(new); diff --git a/mm/swapfile.c b/mm/swapfile.c index 7faa30f460e4..fdeb2c4e6ae6 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1933,8 +1933,6 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, dec_mm_counter(vma->vm_mm, MM_SWAPENTS); inc_mm_counter(vma->vm_mm, MM_ANONPAGES); get_page(page); - set_pte_at(vma->vm_mm, addr, pte, - pte_mkold(mk_pte(page, vma->vm_page_prot))); reliable_page_counter(page, vma->vm_mm, 1); if (page == swapcache) { @@ -1943,6 +1941,8 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, page_add_new_anon_rmap(page, vma, addr, false); lru_cache_add_inactive_or_unevictable(page, vma); } + set_pte_at(vma->vm_mm, addr, pte, + pte_mkold(mk_pte(page, vma->vm_page_prot))); swap_free(entry); out: pte_unmap_unlock(pte, ptl); -- Gitee From 3638d7e316c2c3f782a381d8b0d1e67c3332fe1b Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Fri, 16 Sep 2022 21:34:31 +0800 Subject: [PATCH 02/13] mm: ptep_clear() page table helper mainline inclusion from mainline-v6.0 commit 08d5b29eac7dd5e6c79b66d390ecbb9219e05931 category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=08d5b29eac7dd5e6c79b66d390ecbb9219e05931 ------------------------------------------------- We have ptep_get_and_clear() and ptep_get_and_clear_full() helpers to clear PTE from user page tables, but there is no variant for simple clear of a present PTE from user page tables without using a low level pte_clear() which can be either native or para-virtualised. Add a new ptep_clear() that can be used in common code to clear PTEs from page table. We will need this call later in order to add a hook for page table check. Link: https://lkml.kernel.org/r/20211221154650.1047963-3-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin Cc: Aneesh Kumar K.V Cc: Dave Hansen Cc: David Rientjes Cc: Frederic Weisbecker Cc: Greg Thelen Cc: "H. Peter Anvin" Cc: Hugh Dickins Cc: Ingo Molnar Cc: Jiri Slaby Cc: Jonathan Corbet Cc: Kees Cook Cc: Masahiro Yamada Cc: Mike Rapoport Cc: Muchun Song Cc: Paul Turner Cc: Peter Zijlstra Cc: Sami Tolvanen Cc: Thomas Gleixner Cc: Wei Xu Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Zeng Zhimin --- Documentation/vm/arch_pgtable_helpers.rst | 6 ++++-- include/linux/pgtable.h | 8 ++++++++ mm/debug_vm_pgtable.c | 2 +- mm/khugepaged.c | 12 ++---------- 4 files changed, 15 insertions(+), 13 deletions(-) diff --git a/Documentation/vm/arch_pgtable_helpers.rst b/Documentation/vm/arch_pgtable_helpers.rst index 552567d863b8..fbe06ec75370 100644 --- a/Documentation/vm/arch_pgtable_helpers.rst +++ b/Documentation/vm/arch_pgtable_helpers.rst @@ -66,9 +66,11 @@ PTE Page Table Helpers +---------------------------+--------------------------------------------------+ | pte_mknotpresent | Invalidates a mapped PTE | +---------------------------+--------------------------------------------------+ -| ptep_get_and_clear | Clears a PTE | +| ptep_clear | Clears a PTE | +---------------------------+--------------------------------------------------+ -| ptep_get_and_clear_full | Clears a PTE | +| ptep_get_and_clear | Clears and returns PTE | ++---------------------------+--------------------------------------------------+ +| ptep_get_and_clear_full | Clears and returns PTE (batched PTE unmap) | +---------------------------+--------------------------------------------------+ | ptep_test_and_clear_young | Clears young from a PTE | +---------------------------+--------------------------------------------------+ diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index f924468d84ec..b090887e4ba4 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -303,6 +303,14 @@ static inline pud_t pudp_huge_get_and_clear_full(struct mm_struct *mm, #endif #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#ifndef __HAVE_ARCH_PTEP_CLEAR +static inline void ptep_clear(struct mm_struct *mm, unsigned long addr, + pte_t *ptep) +{ + pte_clear(mm, addr, ptep); +} +#endif + #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, unsigned long address, pte_t *ptep, diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 11d3b46ba187..63a438791e7b 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -614,7 +614,7 @@ static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep, #endif set_pte_at(mm, vaddr, ptep, pte); barrier(); - pte_clear(mm, vaddr, ptep); + ptep_clear(mm, vaddr, ptep); pte = ptep_get(ptep); WARN_ON(!pte_none(pte)); } diff --git a/mm/khugepaged.c b/mm/khugepaged.c index aaef16aa8945..05451c7f97bc 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -754,11 +754,7 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page, * ptl mostly unnecessary. */ spin_lock(ptl); - /* - * paravirt calls inside pte_clear here are - * superfluous. - */ - pte_clear(vma->vm_mm, address, _pte); + ptep_clear(vma->vm_mm, address, _pte); spin_unlock(ptl); } } else { @@ -772,11 +768,7 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page, * inside page_remove_rmap(). */ spin_lock(ptl); - /* - * paravirt calls inside pte_clear here are - * superfluous. - */ - pte_clear(vma->vm_mm, address, _pte); + ptep_clear(vma->vm_mm, address, _pte); reliable_page_counter(src_page, vma->vm_mm, -1); page_remove_rmap(src_page, false); spin_unlock(ptl); -- Gitee From 520cd417b61d4136ea585bd0213fec72936e7aca Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Fri, 16 Sep 2022 21:58:04 +0800 Subject: [PATCH 03/13] mm: page table check mainline inclusion from mainline-v6.0 commit df4e817b710809425d899340dbfa8504a3ca4ba5 category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=df4e817b710809425d899340dbfa8504a3ca4ba5 ------------------------------------------------- Check user page table entries at the time they are added and removed. Allows to synchronously catch memory corruption issues related to double mapping. When a pte for an anonymous page is added into page table, we verify that this pte does not already point to a file backed page, and vice versa if this is a file backed page that is being added we verify that this page does not have an anonymous mapping We also enforce that read-only sharing for anonymous pages is allowed (i.e. cow after fork). All other sharing must be for file pages. Page table check allows to protect and debug cases where "struct page" metadata became corrupted for some reason. For example, when refcnt or mapcount become invalid. Link: https://lkml.kernel.org/r/20211221154650.1047963-4-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin Cc: Aneesh Kumar K.V Cc: Dave Hansen Cc: David Rientjes Cc: Frederic Weisbecker Cc: Greg Thelen Cc: "H. Peter Anvin" Cc: Hugh Dickins Cc: Ingo Molnar Cc: Jiri Slaby Cc: Jonathan Corbet Cc: Kees Cook Cc: Masahiro Yamada Cc: Mike Rapoport Cc: Muchun Song Cc: Paul Turner Cc: Peter Zijlstra Cc: Sami Tolvanen Cc: Thomas Gleixner Cc: Wei Xu Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Zeng Zhimin --- Documentation/vm/index.rst | 1 + Documentation/vm/page_table_check.rst | 56 ++++++ MAINTAINERS | 9 + arch/Kconfig | 3 + include/linux/page_table_check.h | 143 ++++++++++++++ mm/Kconfig.debug | 24 +++ mm/Makefile | 1 + mm/page_alloc.c | 4 + mm/page_ext.c | 4 + mm/page_table_check.c | 266 ++++++++++++++++++++++++++ 10 files changed, 511 insertions(+) create mode 100644 Documentation/vm/page_table_check.rst create mode 100644 include/linux/page_table_check.h create mode 100644 mm/page_table_check.c diff --git a/Documentation/vm/index.rst b/Documentation/vm/index.rst index 6f5ffef4b716..43bb54d897d9 100644 --- a/Documentation/vm/index.rst +++ b/Documentation/vm/index.rst @@ -31,6 +31,7 @@ algorithms. If you are looking for advice on simply allocating memory, see the page_migration page_frags page_owner + page_table_check remap_file_pages slub split_page_table_lock diff --git a/Documentation/vm/page_table_check.rst b/Documentation/vm/page_table_check.rst new file mode 100644 index 000000000000..81f521ff7ea7 --- /dev/null +++ b/Documentation/vm/page_table_check.rst @@ -0,0 +1,56 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. _page_table_check: + +================ +Page Table Check +================ + +Introduction +============ + +Page table check allows to hardern the kernel by ensuring that some types of +the memory corruptions are prevented. + +Page table check performs extra verifications at the time when new pages become +accessible from the userspace by getting their page table entries (PTEs PMDs +etc.) added into the table. + +In case of detected corruption, the kernel is crashed. There is a small +performance and memory overhead associated with the page table check. Therefore, +it is disabled by default, but can be optionally enabled on systems where the +extra hardening outweighs the performance costs. Also, because page table check +is synchronous, it can help with debugging double map memory corruption issues, +by crashing kernel at the time wrong mapping occurs instead of later which is +often the case with memory corruptions bugs. + +Double mapping detection logic +============================== + ++-------------------+-------------------+-------------------+------------------+ +| Current Mapping | New mapping | Permissions | Rule | ++===================+===================+===================+==================+ +| Anonymous | Anonymous | Read | Allow | ++-------------------+-------------------+-------------------+------------------+ +| Anonymous | Anonymous | Read / Write | Prohibit | ++-------------------+-------------------+-------------------+------------------+ +| Anonymous | Named | Any | Prohibit | ++-------------------+-------------------+-------------------+------------------+ +| Named | Anonymous | Any | Prohibit | ++-------------------+-------------------+-------------------+------------------+ +| Named | Named | Any | Allow | ++-------------------+-------------------+-------------------+------------------+ + +Enabling Page Table Check +========================= + +Build kernel with: + +- PAGE_TABLE_CHECK=y + Note, it can only be enabled on platforms where ARCH_SUPPORTS_PAGE_TABLE_CHECK + is available. + +- Boot with 'page_table_check=on' kernel parameter. + +Optionally, build kernel with PAGE_TABLE_CHECK_ENFORCED in order to have page +table support without extra kernel parameter. diff --git a/MAINTAINERS b/MAINTAINERS index a9ae6acec16c..e228dc4d2e24 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -13270,6 +13270,15 @@ F: include/net/page_pool.h F: include/trace/events/page_pool.h F: net/core/page_pool.c +PAGE TABLE CHECK +M: Pasha Tatashin +M: Andrew Morton +L: linux-mm@kvack.org +S: Maintained +F: Documentation/vm/page_table_check.rst +F: include/linux/page_table_check.h +F: mm/page_table_check.c + PANASONIC LAPTOP ACPI EXTRAS DRIVER M: Harald Welte L: platform-driver-x86@vger.kernel.org diff --git a/arch/Kconfig b/arch/Kconfig index 47c626138d5b..a271278c6fbc 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1119,6 +1119,9 @@ config ARCH_WANT_LD_ORPHAN_WARN by the linker, since the locations of such sections can change between linker versions. +config ARCH_SUPPORTS_PAGE_TABLE_CHECK + bool + config ARCH_SPLIT_ARG64 bool help diff --git a/include/linux/page_table_check.h b/include/linux/page_table_check.h new file mode 100644 index 000000000000..93960519f743 --- /dev/null +++ b/include/linux/page_table_check.h @@ -0,0 +1,143 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __LINUX_PAGE_TABLE_CHECK_H +#define __LINUX_PAGE_TABLE_CHECK_H + +#ifdef CONFIG_PAGE_TABLE_CHECK +#include + +extern struct static_key_true page_table_check_disabled; +extern struct page_ext_operations page_table_check_ops; + +void __page_table_check_zero(struct page *page, unsigned int order); +void __page_table_check_pte_clear(struct mm_struct *mm, unsigned long addr, + pte_t pte); +void __page_table_check_pmd_clear(struct mm_struct *mm, unsigned long addr, + pmd_t pmd); +void __page_table_check_pud_clear(struct mm_struct *mm, unsigned long addr, + pud_t pud); +void __page_table_check_pte_set(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, pte_t pte); +void __page_table_check_pmd_set(struct mm_struct *mm, unsigned long addr, + pmd_t *pmdp, pmd_t pmd); +void __page_table_check_pud_set(struct mm_struct *mm, unsigned long addr, + pud_t *pudp, pud_t pud); + +static inline void page_table_check_alloc(struct page *page, unsigned int order) +{ + if (static_branch_likely(&page_table_check_disabled)) + return; + + __page_table_check_zero(page, order); +} + +static inline void page_table_check_free(struct page *page, unsigned int order) +{ + if (static_branch_likely(&page_table_check_disabled)) + return; + + __page_table_check_zero(page, order); +} + +static inline void page_table_check_pte_clear(struct mm_struct *mm, + unsigned long addr, pte_t pte) +{ + if (static_branch_likely(&page_table_check_disabled)) + return; + + __page_table_check_pte_clear(mm, addr, pte); +} + +static inline void page_table_check_pmd_clear(struct mm_struct *mm, + unsigned long addr, pmd_t pmd) +{ + if (static_branch_likely(&page_table_check_disabled)) + return; + + __page_table_check_pmd_clear(mm, addr, pmd); +} + +static inline void page_table_check_pud_clear(struct mm_struct *mm, + unsigned long addr, pud_t pud) +{ + if (static_branch_likely(&page_table_check_disabled)) + return; + + __page_table_check_pud_clear(mm, addr, pud); +} + +static inline void page_table_check_pte_set(struct mm_struct *mm, + unsigned long addr, pte_t *ptep, + pte_t pte) +{ + if (static_branch_likely(&page_table_check_disabled)) + return; + + __page_table_check_pte_set(mm, addr, ptep, pte); +} + +static inline void page_table_check_pmd_set(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp, + pmd_t pmd) +{ + if (static_branch_likely(&page_table_check_disabled)) + return; + + __page_table_check_pmd_set(mm, addr, pmdp, pmd); +} + +static inline void page_table_check_pud_set(struct mm_struct *mm, + unsigned long addr, pud_t *pudp, + pud_t pud) +{ + if (static_branch_likely(&page_table_check_disabled)) + return; + + __page_table_check_pud_set(mm, addr, pudp, pud); +} + +#else + +static inline void page_table_check_alloc(struct page *page, unsigned int order) +{ +} + +static inline void page_table_check_free(struct page *page, unsigned int order) +{ +} + +static inline void page_table_check_pte_clear(struct mm_struct *mm, + unsigned long addr, pte_t pte) +{ +} + +static inline void page_table_check_pmd_clear(struct mm_struct *mm, + unsigned long addr, pmd_t pmd) +{ +} + +static inline void page_table_check_pud_clear(struct mm_struct *mm, + unsigned long addr, pud_t pud) +{ +} + +static inline void page_table_check_pte_set(struct mm_struct *mm, + unsigned long addr, pte_t *ptep, + pte_t pte) +{ +} + +static inline void page_table_check_pmd_set(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp, + pmd_t pmd) +{ +} + +static inline void page_table_check_pud_set(struct mm_struct *mm, + unsigned long addr, pud_t *pudp, + pud_t pud) +{ +} + +#endif /* CONFIG_PAGE_TABLE_CHECK */ +#endif /* __LINUX_PAGE_TABLE_CHECK_H */ diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 864f129f1937..b04d3a4ddfce 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -62,6 +62,30 @@ config PAGE_OWNER If unsure, say N. +config PAGE_TABLE_CHECK + bool "Check for invalid mappings in user page tables" + depends on ARCH_SUPPORTS_PAGE_TABLE_CHECK + select PAGE_EXTENSION + help + Check that anonymous page is not being mapped twice with read write + permissions. Check that anonymous and file pages are not being + erroneously shared. Since the checking is performed at the time + entries are added and removed to user page tables, leaking, corruption + and double mapping problems are detected synchronously. + + If unsure say "n". + +config PAGE_TABLE_CHECK_ENFORCED + bool "Enforce the page table checking by default" + depends on PAGE_TABLE_CHECK + help + Always enable page table checking. By default the page table checking + is disabled, and can be optionally enabled via page_table_check=on + kernel parameter. This config enforces that page table check is always + enabled. + + If unsure say "n". + config PAGE_POISONING bool "Poison pages after freeing" select PAGE_POISONING_NO_SANITY if HIBERNATION diff --git a/mm/Makefile b/mm/Makefile index aad7866abe8c..366d9f62bfea 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -111,6 +111,7 @@ obj-$(CONFIG_GENERIC_EARLY_IOREMAP) += early_ioremap.o obj-$(CONFIG_CMA) += cma.o obj-$(CONFIG_MEMORY_BALLOON) += balloon_compaction.o obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o +obj-$(CONFIG_PAGE_TABLE_CHECK) += page_table_check.o obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o obj-$(CONFIG_USERFAULTFD) += userfaultfd.o obj-$(CONFIG_IDLE_PAGE_TRACKING) += page_idle.o diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 24116b7828f5..60b2351ede77 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -62,6 +62,7 @@ #include #include #include +#include #include #include #include @@ -1221,6 +1222,7 @@ __always_inline bool free_pages_prepare(struct page *page, if (memcg_kmem_enabled() && PageMemcgKmem(page)) __memcg_kmem_uncharge_page(page, order); reset_page_owner(page, order); + page_table_check_free(page, order); return false; } @@ -1258,6 +1260,7 @@ __always_inline bool free_pages_prepare(struct page *page, page_cpupid_reset_last(page); page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; reset_page_owner(page, order); + page_table_check_free(page, order); if (!PageHighMem(page)) { debug_check_no_locks_freed(page_address(page), @@ -2282,6 +2285,7 @@ inline void post_alloc_hook(struct page *page, unsigned int order, kasan_alloc_pages(page, order); kernel_poison_pages(page, 1 << order, 1); set_page_owner(page, order, gfp_flags); + page_table_check_alloc(page, order); } void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags, diff --git a/mm/page_ext.c b/mm/page_ext.c index 8e59da0f4367..d541923a2406 100644 --- a/mm/page_ext.c +++ b/mm/page_ext.c @@ -8,6 +8,7 @@ #include #include #include +#include /* * struct page extension @@ -75,6 +76,9 @@ static struct page_ext_operations *page_ext_ops[] = { #if defined(CONFIG_PAGE_IDLE_FLAG) && !defined(CONFIG_64BIT) &page_idle_ops, #endif +#ifdef CONFIG_PAGE_TABLE_CHECK + &page_table_check_ops, +#endif }; unsigned long page_ext_size = sizeof(struct page_ext); diff --git a/mm/page_table_check.c b/mm/page_table_check.c new file mode 100644 index 000000000000..5351fb81692d --- /dev/null +++ b/mm/page_table_check.c @@ -0,0 +1,266 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +#undef pr_fmt +#define pr_fmt(fmt) "page_table_check: " fmt + +struct page_table_check { + atomic_t anon_map_count; + atomic_t file_map_count; +}; + +static bool __page_table_check_enabled __initdata = + IS_ENABLED(CONFIG_PAGE_TABLE_CHECK_ENFORCED); + +DEFINE_STATIC_KEY_TRUE(page_table_check_disabled); +EXPORT_SYMBOL(page_table_check_disabled); + +static int __init early_page_table_check_param(char *buf) +{ + if (!buf) + return -EINVAL; + + if (strcmp(buf, "on") == 0) + __page_table_check_enabled = true; + else if (strcmp(buf, "off") == 0) + __page_table_check_enabled = false; + + return 0; +} + +early_param("page_table_check", early_page_table_check_param); + +static bool __init need_page_table_check(void) +{ + return __page_table_check_enabled; +} + +static void __init init_page_table_check(void) +{ + if (!__page_table_check_enabled) + return; + static_branch_disable(&page_table_check_disabled); +} + +struct page_ext_operations page_table_check_ops = { + .size = sizeof(struct page_table_check), + .need = need_page_table_check, + .init = init_page_table_check, +}; + +static struct page_table_check *get_page_table_check(struct page_ext *page_ext) +{ + BUG_ON(!page_ext); + return (void *)(page_ext) + page_table_check_ops.offset; +} + +static inline bool pte_user_accessible_page(pte_t pte) +{ + return (pte_val(pte) & _PAGE_PRESENT) && (pte_val(pte) & _PAGE_USER); +} + +static inline bool pmd_user_accessible_page(pmd_t pmd) +{ + return pmd_leaf(pmd) && (pmd_val(pmd) & _PAGE_PRESENT) && + (pmd_val(pmd) & _PAGE_USER); +} + +static inline bool pud_user_accessible_page(pud_t pud) +{ + return pud_leaf(pud) && (pud_val(pud) & _PAGE_PRESENT) && + (pud_val(pud) & _PAGE_USER); +} + +/* + * An enty is removed from the page table, decrement the counters for that page + * verify that it is of correct type and counters do not become negative. + */ +static void page_table_check_clear(struct mm_struct *mm, unsigned long addr, + unsigned long pfn, unsigned long pgcnt) +{ + struct page_ext *page_ext; + struct page *page; + bool anon; + int i; + + if (!pfn_valid(pfn)) + return; + + page = pfn_to_page(pfn); + page_ext = lookup_page_ext(page); + anon = PageAnon(page); + + for (i = 0; i < pgcnt; i++) { + struct page_table_check *ptc = get_page_table_check(page_ext); + + if (anon) { + BUG_ON(atomic_read(&ptc->file_map_count)); + BUG_ON(atomic_dec_return(&ptc->anon_map_count) < 0); + } else { + BUG_ON(atomic_read(&ptc->anon_map_count)); + BUG_ON(atomic_dec_return(&ptc->file_map_count) < 0); + } + page_ext = page_ext_next(page_ext); + } +} + +/* + * A new enty is added to the page table, increment the counters for that page + * verify that it is of correct type and is not being mapped with a different + * type to a different process. + */ +static void page_table_check_set(struct mm_struct *mm, unsigned long addr, + unsigned long pfn, unsigned long pgcnt, + bool rw) +{ + struct page_ext *page_ext; + struct page *page; + bool anon; + int i; + + if (!pfn_valid(pfn)) + return; + + page = pfn_to_page(pfn); + page_ext = lookup_page_ext(page); + anon = PageAnon(page); + + for (i = 0; i < pgcnt; i++) { + struct page_table_check *ptc = get_page_table_check(page_ext); + + if (anon) { + BUG_ON(atomic_read(&ptc->file_map_count)); + BUG_ON(atomic_inc_return(&ptc->anon_map_count) > 1 && rw); + } else { + BUG_ON(atomic_read(&ptc->anon_map_count)); + BUG_ON(atomic_inc_return(&ptc->file_map_count) < 0); + } + page_ext = page_ext_next(page_ext); + } +} + +/* + * page is on free list, or is being allocated, verify that counters are zeroes + * crash if they are not. + */ +void __page_table_check_zero(struct page *page, unsigned int order) +{ + struct page_ext *page_ext = lookup_page_ext(page); + int i; + + BUG_ON(!page_ext); + for (i = 0; i < (1 << order); i++) { + struct page_table_check *ptc = get_page_table_check(page_ext); + + BUG_ON(atomic_read(&ptc->anon_map_count)); + BUG_ON(atomic_read(&ptc->file_map_count)); + page_ext = page_ext_next(page_ext); + } +} + +void __page_table_check_pte_clear(struct mm_struct *mm, unsigned long addr, + pte_t pte) +{ + if (&init_mm == mm) + return; + + if (pte_user_accessible_page(pte)) { + page_table_check_clear(mm, addr, pte_pfn(pte), + PAGE_SIZE >> PAGE_SHIFT); + } +} +EXPORT_SYMBOL(__page_table_check_pte_clear); + +void __page_table_check_pmd_clear(struct mm_struct *mm, unsigned long addr, + pmd_t pmd) +{ + if (&init_mm == mm) + return; + + if (pmd_user_accessible_page(pmd)) { + page_table_check_clear(mm, addr, pmd_pfn(pmd), + PMD_PAGE_SIZE >> PAGE_SHIFT); + } +} +EXPORT_SYMBOL(__page_table_check_pmd_clear); + +void __page_table_check_pud_clear(struct mm_struct *mm, unsigned long addr, + pud_t pud) +{ + if (&init_mm == mm) + return; + + if (pud_user_accessible_page(pud)) { + page_table_check_clear(mm, addr, pud_pfn(pud), + PUD_PAGE_SIZE >> PAGE_SHIFT); + } +} +EXPORT_SYMBOL(__page_table_check_pud_clear); + +void __page_table_check_pte_set(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, pte_t pte) +{ + pte_t old_pte; + + if (&init_mm == mm) + return; + + old_pte = *ptep; + if (pte_user_accessible_page(old_pte)) { + page_table_check_clear(mm, addr, pte_pfn(old_pte), + PAGE_SIZE >> PAGE_SHIFT); + } + + if (pte_user_accessible_page(pte)) { + page_table_check_set(mm, addr, pte_pfn(pte), + PAGE_SIZE >> PAGE_SHIFT, + pte_write(pte)); + } +} +EXPORT_SYMBOL(__page_table_check_pte_set); + +void __page_table_check_pmd_set(struct mm_struct *mm, unsigned long addr, + pmd_t *pmdp, pmd_t pmd) +{ + pmd_t old_pmd; + + if (&init_mm == mm) + return; + + old_pmd = *pmdp; + if (pmd_user_accessible_page(old_pmd)) { + page_table_check_clear(mm, addr, pmd_pfn(old_pmd), + PMD_PAGE_SIZE >> PAGE_SHIFT); + } + + if (pmd_user_accessible_page(pmd)) { + page_table_check_set(mm, addr, pmd_pfn(pmd), + PMD_PAGE_SIZE >> PAGE_SHIFT, + pmd_write(pmd)); + } +} +EXPORT_SYMBOL(__page_table_check_pmd_set); + +void __page_table_check_pud_set(struct mm_struct *mm, unsigned long addr, + pud_t *pudp, pud_t pud) +{ + pud_t old_pud; + + if (&init_mm == mm) + return; + + old_pud = *pudp; + if (pud_user_accessible_page(old_pud)) { + page_table_check_clear(mm, addr, pud_pfn(old_pud), + PUD_PAGE_SIZE >> PAGE_SHIFT); + } + + if (pud_user_accessible_page(pud)) { + page_table_check_set(mm, addr, pud_pfn(pud), + PUD_PAGE_SIZE >> PAGE_SHIFT, + pud_write(pud)); + } +} +EXPORT_SYMBOL(__page_table_check_pud_set); -- Gitee From ec9e357e2ea8ad86f63bf5f6a7f8d67327e845cc Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Fri, 16 Sep 2022 22:09:32 +0800 Subject: [PATCH 04/13] x86: mm: add x86_64 support for page table check mainline inclusion from mainline-v6.0 commit d283d422c6c4f0264fe8ecf5ae80036bf73f4594 category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d283d422c6c4f0264fe8ecf5ae80036bf73f4594 ------------------------------------------------- Add page table check hooks into routines that modify user page tables. Link: https://lkml.kernel.org/r/20211221154650.1047963-5-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin Cc: Aneesh Kumar K.V Cc: Dave Hansen Cc: David Rientjes Cc: Frederic Weisbecker Cc: Greg Thelen Cc: "H. Peter Anvin" Cc: Hugh Dickins Cc: Ingo Molnar Cc: Jiri Slaby Cc: Jonathan Corbet Cc: Kees Cook Cc: Masahiro Yamada Cc: Mike Rapoport Cc: Muchun Song Cc: Paul Turner Cc: Peter Zijlstra Cc: Sami Tolvanen Cc: Thomas Gleixner Cc: Wei Xu Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Zeng Zhimin --- arch/x86/Kconfig | 1 + arch/x86/include/asm/pgtable.h | 29 +++++++++++++++++++++++++++-- 2 files changed, 28 insertions(+), 2 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index b5ca6f54b323..ba48644da7cd 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -94,6 +94,7 @@ config X86 select ARCH_STACKWALK select ARCH_SUPPORTS_ACPI select ARCH_SUPPORTS_ATOMIC_RMW + select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_QUEUED_RWLOCKS diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 788b3a0120dc..8fdb8d84d122 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -26,6 +26,7 @@ #include #include #include +#include extern pgd_t early_top_pgt[PTRS_PER_PGD]; bool __init __early_make_pgtable(unsigned long address, pmdval_t pmd); @@ -1006,18 +1007,21 @@ static inline pud_t native_local_pudp_get_and_clear(pud_t *pudp) static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte) { + page_table_check_pte_set(mm, addr, ptep, pte); set_pte(ptep, pte); } static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pmd_t pmd) { + page_table_check_pmd_set(mm, addr, pmdp, pmd); set_pmd(pmdp, pmd); } static inline void set_pud_at(struct mm_struct *mm, unsigned long addr, pud_t *pudp, pud_t pud) { + page_table_check_pud_set(mm, addr, pudp, pud); native_set_pud(pudp, pud); } @@ -1048,6 +1052,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { pte_t pte = native_ptep_get_and_clear(ptep); + page_table_check_pte_clear(mm, addr, pte); return pte; } @@ -1063,12 +1068,23 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, * care about updates and native needs no locking */ pte = native_local_ptep_get_and_clear(ptep); + page_table_check_pte_clear(mm, addr, pte); } else { pte = ptep_get_and_clear(mm, addr, ptep); } return pte; } +#define __HAVE_ARCH_PTEP_CLEAR +static inline void ptep_clear(struct mm_struct *mm, unsigned long addr, + pte_t *ptep) +{ + if (IS_ENABLED(CONFIG_PAGE_TABLE_CHECK)) + ptep_get_and_clear(mm, addr, ptep); + else + pte_clear(mm, addr, ptep); +} + #define __HAVE_ARCH_PTEP_SET_WRPROTECT static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) @@ -1109,14 +1125,22 @@ static inline int pmd_write(pmd_t pmd) static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp) { - return native_pmdp_get_and_clear(pmdp); + pmd_t pmd = native_pmdp_get_and_clear(pmdp); + + page_table_check_pmd_clear(mm, addr, pmd); + + return pmd; } #define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm, unsigned long addr, pud_t *pudp) { - return native_pudp_get_and_clear(pudp); + pud_t pud = native_pudp_get_and_clear(pudp); + + page_table_check_pud_clear(mm, addr, pud); + + return pud; } #define __HAVE_ARCH_PMDP_SET_WRPROTECT @@ -1137,6 +1161,7 @@ static inline int pud_write(pud_t pud) static inline pmd_t pmdp_establish(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp, pmd_t pmd) { + page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd); if (IS_ENABLED(CONFIG_SMP)) { return xchg(pmdp, pmd); } else { -- Gitee From b8dc8a21d5f752c64feea2bbb05bdca6b159ee59 Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Fri, 16 Sep 2022 23:12:05 +0800 Subject: [PATCH 05/13] mm/page_table_check: use unsigned long for page counters and cleanup mainline inclusion from mainline-v6.0 commit 64d8b9e14512ceb7bf11b235faeb8531aeb4d9d3 category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=64d8b9e14512ceb7bf11b235faeb8531aeb4d9d3 ------------------------------------------------- For consistency, use "unsigned long" for all page counters. Also, reduce code duplication by calling __page_table_check_*_clear() from __page_table_check_*_set() functions. Link: https://lkml.kernel.org/r/20220131203249.2832273-3-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin Reviewed-by: Wei Xu Acked-by: David Rientjes Cc: Aneesh Kumar K.V Cc: Anshuman Khandual Cc: Dave Hansen Cc: Greg Thelen Cc: H. Peter Anvin Cc: Hugh Dickins Cc: Ingo Molnar Cc: Jiri Slaby Cc: Mike Rapoport Cc: Muchun Song Cc: Paul Turner Cc: Will Deacon Cc: Zi Yan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Zeng Zhimin --- mm/page_table_check.c | 35 +++++++---------------------------- 1 file changed, 7 insertions(+), 28 deletions(-) diff --git a/mm/page_table_check.c b/mm/page_table_check.c index 5351fb81692d..f0813434c8c2 100644 --- a/mm/page_table_check.c +++ b/mm/page_table_check.c @@ -82,8 +82,8 @@ static void page_table_check_clear(struct mm_struct *mm, unsigned long addr, { struct page_ext *page_ext; struct page *page; + unsigned long i; bool anon; - int i; if (!pfn_valid(pfn)) return; @@ -117,8 +117,8 @@ static void page_table_check_set(struct mm_struct *mm, unsigned long addr, { struct page_ext *page_ext; struct page *page; + unsigned long i; bool anon; - int i; if (!pfn_valid(pfn)) return; @@ -148,10 +148,10 @@ static void page_table_check_set(struct mm_struct *mm, unsigned long addr, void __page_table_check_zero(struct page *page, unsigned int order) { struct page_ext *page_ext = lookup_page_ext(page); - int i; + unsigned long i; BUG_ON(!page_ext); - for (i = 0; i < (1 << order); i++) { + for (i = 0; i < (1ul << order); i++) { struct page_table_check *ptc = get_page_table_check(page_ext); BUG_ON(atomic_read(&ptc->anon_map_count)); @@ -202,17 +202,10 @@ EXPORT_SYMBOL(__page_table_check_pud_clear); void __page_table_check_pte_set(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte) { - pte_t old_pte; - if (&init_mm == mm) return; - old_pte = *ptep; - if (pte_user_accessible_page(old_pte)) { - page_table_check_clear(mm, addr, pte_pfn(old_pte), - PAGE_SIZE >> PAGE_SHIFT); - } - + __page_table_check_pte_clear(mm, addr, *ptep); if (pte_user_accessible_page(pte)) { page_table_check_set(mm, addr, pte_pfn(pte), PAGE_SIZE >> PAGE_SHIFT, @@ -224,17 +217,10 @@ EXPORT_SYMBOL(__page_table_check_pte_set); void __page_table_check_pmd_set(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pmd_t pmd) { - pmd_t old_pmd; - if (&init_mm == mm) return; - old_pmd = *pmdp; - if (pmd_user_accessible_page(old_pmd)) { - page_table_check_clear(mm, addr, pmd_pfn(old_pmd), - PMD_PAGE_SIZE >> PAGE_SHIFT); - } - + __page_table_check_pmd_clear(mm, addr, *pmdp); if (pmd_user_accessible_page(pmd)) { page_table_check_set(mm, addr, pmd_pfn(pmd), PMD_PAGE_SIZE >> PAGE_SHIFT, @@ -246,17 +232,10 @@ EXPORT_SYMBOL(__page_table_check_pmd_set); void __page_table_check_pud_set(struct mm_struct *mm, unsigned long addr, pud_t *pudp, pud_t pud) { - pud_t old_pud; - if (&init_mm == mm) return; - old_pud = *pudp; - if (pud_user_accessible_page(old_pud)) { - page_table_check_clear(mm, addr, pud_pfn(old_pud), - PUD_PAGE_SIZE >> PAGE_SHIFT); - } - + __page_table_check_pud_clear(mm, addr, *pudp); if (pud_user_accessible_page(pud)) { page_table_check_set(mm, addr, pud_pfn(pud), PUD_PAGE_SIZE >> PAGE_SHIFT, -- Gitee From 648e4cdc4631c839b0b402d887bdf43fbdd2702c Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Fri, 16 Sep 2022 23:20:40 +0800 Subject: [PATCH 06/13] mm/khugepaged: unify collapse pmd clear, flush and free mainline inclusion from mainline-v6.0 commit e59a47b8a45353d9ee234aab2d229474e09885df category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e59a47b8a45353d9ee234aab2d229474e09885df ------------------------------------------------- Unify the code that flushes, clears pmd entry, and frees the PTE table level into a new function collapse_and_free_pmd(). This cleanup is useful as in the next patch we will add another call to this function to iterate through PTE prior to freeing the level for page table check. Link: https://lkml.kernel.org/r/20220131203249.2832273-4-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin Acked-by: David Rientjes Cc: Aneesh Kumar K.V Cc: Anshuman Khandual Cc: Dave Hansen Cc: Greg Thelen Cc: H. Peter Anvin Cc: Hugh Dickins Cc: Ingo Molnar Cc: Jiri Slaby Cc: Mike Rapoport Cc: Muchun Song Cc: Paul Turner Cc: Wei Xu Cc: Will Deacon Cc: Zi Yan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Zeng Zhimin --- mm/khugepaged.c | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 05451c7f97bc..78e9a445e02d 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1427,6 +1427,19 @@ static int khugepaged_add_pte_mapped_thp(struct mm_struct *mm, return 0; } +static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long addr, pmd_t *pmdp) +{ + spinlock_t *ptl; + pmd_t pmd; + + ptl = pmd_lock(vma->vm_mm, pmdp); + pmd = pmdp_collapse_flush(vma, addr, pmdp); + spin_unlock(ptl); + mm_dec_nr_ptes(mm); + pte_free(mm, pmd_pgtable(pmd)); +} + /** * Try to collapse a pte-mapped THP for mm at address haddr. * @@ -1440,7 +1453,7 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr) struct vm_area_struct *vma = find_vma(mm, haddr); struct page *hpage; pte_t *start_pte, *pte; - pmd_t *pmd, _pmd; + pmd_t *pmd; spinlock_t *ptl; int count = 0; int i; @@ -1517,11 +1530,7 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr) } /* step 4: collapse pmd */ - ptl = pmd_lock(vma->vm_mm, pmd); - _pmd = pmdp_collapse_flush(vma, haddr, pmd); - spin_unlock(ptl); - mm_dec_nr_ptes(mm); - pte_free(mm, pmd_pgtable(_pmd)); + collapse_and_free_pmd(mm, vma, haddr, pmd); drop_hpage: unlock_page(hpage); @@ -1561,7 +1570,7 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff) struct vm_area_struct *vma; struct mm_struct *mm; unsigned long addr; - pmd_t *pmd, _pmd; + pmd_t *pmd; i_mmap_lock_write(mapping); vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { @@ -1600,14 +1609,8 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff) * reverse order. Trylock is a way to avoid deadlock. */ if (mmap_write_trylock(mm)) { - if (!khugepaged_test_exit(mm)) { - spinlock_t *ptl = pmd_lock(mm, pmd); - /* assume page table is clear */ - _pmd = pmdp_collapse_flush(vma, addr, pmd); - spin_unlock(ptl); - mm_dec_nr_ptes(mm); - pte_free(mm, pmd_pgtable(_pmd)); - } + if (!khugepaged_test_exit(mm)) + collapse_and_free_pmd(mm, vma, addr, pmd); mmap_write_unlock(mm); } else { /* Try again later */ -- Gitee From 03db71b7732b6687ec25e64047946a6a0425509f Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Fri, 16 Sep 2022 23:31:52 +0800 Subject: [PATCH 07/13] mm/page_table_check: check entries at pmd levels mainline inclusion from mainline-v6.0 commit 80110bbfbba6f0078d5a1cbc8df004506db8ffe5 category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=80110bbfbba6f0078d5a1cbc8df004506db8ffe5 syzbot detected a case where the page table counters were not properly updated. syzkaller login: ------------[ cut here ]------------ kernel BUG at mm/page_table_check.c:162! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 3099 Comm: pasha Not tainted 5.16.0+ #48 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIO4 RIP: 0010:__page_table_check_zero+0x159/0x1a0 Call Trace: free_pcp_prepare+0x3be/0xaa0 free_unref_page+0x1c/0x650 free_compound_page+0xec/0x130 free_transhuge_page+0x1be/0x260 __put_compound_page+0x90/0xd0 release_pages+0x54c/0x1060 __pagevec_release+0x7c/0x110 shmem_undo_range+0x85e/0x1250 ... The repro involved having a huge page that is split due to uprobe event temporarily replacing one of the pages in the huge page. Later the huge page was combined again, but the counters were off, as the PTE level was not properly updated. Make sure that when PMD is cleared and prior to freeing the level the PTEs are updated. Link: https://lkml.kernel.org/r/20220131203249.2832273-5-pasha.tatashin@soleen.com Fixes: df4e817b7108 ("mm: page table check") Signed-off-by: Pasha Tatashin Acked-by: David Rientjes Cc: Aneesh Kumar K.V Cc: Anshuman Khandual Cc: Dave Hansen Cc: Greg Thelen Cc: H. Peter Anvin Cc: Hugh Dickins Cc: Ingo Molnar Cc: Jiri Slaby Cc: Mike Rapoport Cc: Muchun Song Cc: Paul Turner Cc: Wei Xu Cc: Will Deacon Cc: Zi Yan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Zeng Zhimin --- include/linux/page_table_check.h | 19 +++++++++++++++++++ mm/khugepaged.c | 3 +++ mm/page_table_check.c | 20 ++++++++++++++++++++ 3 files changed, 42 insertions(+) diff --git a/include/linux/page_table_check.h b/include/linux/page_table_check.h index 93960519f743..e387791a04a6 100644 --- a/include/linux/page_table_check.h +++ b/include/linux/page_table_check.h @@ -22,6 +22,9 @@ void __page_table_check_pmd_set(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pmd_t pmd); void __page_table_check_pud_set(struct mm_struct *mm, unsigned long addr, pud_t *pudp, pud_t pud); +void __page_table_check_pte_clear_range(struct mm_struct *mm, + unsigned long addr, + pmd_t pmd); static inline void page_table_check_alloc(struct page *page, unsigned int order) { @@ -96,6 +99,16 @@ static inline void page_table_check_pud_set(struct mm_struct *mm, __page_table_check_pud_set(mm, addr, pudp, pud); } +static inline void page_table_check_pte_clear_range(struct mm_struct *mm, + unsigned long addr, + pmd_t pmd) +{ + if (static_branch_likely(&page_table_check_disabled)) + return; + + __page_table_check_pte_clear_range(mm, addr, pmd); +} + #else static inline void page_table_check_alloc(struct page *page, unsigned int order) @@ -139,5 +152,11 @@ static inline void page_table_check_pud_set(struct mm_struct *mm, { } +static inline void page_table_check_pte_clear_range(struct mm_struct *mm, + unsigned long addr, + pmd_t pmd) +{ +} + #endif /* CONFIG_PAGE_TABLE_CHECK */ #endif /* __LINUX_PAGE_TABLE_CHECK_H */ diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 78e9a445e02d..faeae65e4b1a 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -1433,10 +1434,12 @@ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *v spinlock_t *ptl; pmd_t pmd; + mmap_assert_write_locked(mm); ptl = pmd_lock(vma->vm_mm, pmdp); pmd = pmdp_collapse_flush(vma, addr, pmdp); spin_unlock(ptl); mm_dec_nr_ptes(mm); + page_table_check_pte_clear_range(mm, addr, pmd); pte_free(mm, pmd_pgtable(pmd)); } diff --git a/mm/page_table_check.c b/mm/page_table_check.c index f0813434c8c2..71d3c59504b5 100644 --- a/mm/page_table_check.c +++ b/mm/page_table_check.c @@ -243,3 +243,23 @@ void __page_table_check_pud_set(struct mm_struct *mm, unsigned long addr, } } EXPORT_SYMBOL(__page_table_check_pud_set); + +void __page_table_check_pte_clear_range(struct mm_struct *mm, + unsigned long addr, + pmd_t pmd) +{ + if (&init_mm == mm) + return; + + if (!pmd_bad(pmd) && !pmd_leaf(pmd)) { + pte_t *ptep = pte_offset_map(&pmd, addr); + unsigned long i; + + pte_unmap(ptep); + for (i = 0; i < PTRS_PER_PTE; i++) { + __page_table_check_pte_clear(mm, addr, *ptep); + addr += PAGE_SIZE; + ptep++; + } + } +} -- Gitee From 86f1e83e52c3241361601a618c1956dcad376b22 Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Fri, 16 Sep 2022 23:51:28 +0800 Subject: [PATCH 08/13] mm: page_table_check: using PxD_SIZE instead of PxD_PAGE_SIZE mainline inclusion from mainline-v6.0 commit 92fb05242a1b1ecfcb39d9b1421a165adf344a3c category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=92fb05242a1b1ecfcb39d9b1421a165adf344a3c ------------------------------------------------- Patch series "mm: page_table_check: add support on arm64 and riscv", v7. Page table check performs extra verifications at the time when new pages become accessible from the userspace by getting their page table entries (PTEs PMDs etc.) added into the table. It is supported on X86[1]. This patchset made some simple changes and make it easier to support new architecture, then we support this feature on ARM64 and RISCV. [1]https://lore.kernel.org/lkml/20211123214814.3756047-1-pasha.tatashin@soleen.com/ This patch (of 6): Compared with PxD_PAGE_SIZE, which is defined and used only on X86, PxD_SIZE is more common in each architecture. Therefore, it is more reasonable to use PxD_SIZE instead of PxD_PAGE_SIZE in page_table_check.c. At the same time, it is easier to support page table check in other architectures. The substitution has no functional impact on the x86. Link: https://lkml.kernel.org/r/20220507110114.4128854-1-tongtiangen@huawei.com Link: https://lkml.kernel.org/r/20220507110114.4128854-2-tongtiangen@huawei.com Signed-off-by: Tong Tiangen Suggested-by: Anshuman Khandual Acked-by: Pasha Tatashin Reviewed-by: Anshuman Khandual Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Catalin Marinas Cc: Will Deacon Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Kefeng Wang Signed-off-by: Andrew Morton (cherry picked from commit 92fb05242a1b1ecfcb39d9b1421a165adf344a3c) Signed-off-by: Kefeng Wang Signed-off-by: Zeng Zhimin --- mm/page_table_check.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/page_table_check.c b/mm/page_table_check.c index 71d3c59504b5..4ef604d14d2f 100644 --- a/mm/page_table_check.c +++ b/mm/page_table_check.c @@ -181,7 +181,7 @@ void __page_table_check_pmd_clear(struct mm_struct *mm, unsigned long addr, if (pmd_user_accessible_page(pmd)) { page_table_check_clear(mm, addr, pmd_pfn(pmd), - PMD_PAGE_SIZE >> PAGE_SHIFT); + PMD_SIZE >> PAGE_SHIFT); } } EXPORT_SYMBOL(__page_table_check_pmd_clear); @@ -194,7 +194,7 @@ void __page_table_check_pud_clear(struct mm_struct *mm, unsigned long addr, if (pud_user_accessible_page(pud)) { page_table_check_clear(mm, addr, pud_pfn(pud), - PUD_PAGE_SIZE >> PAGE_SHIFT); + PUD_SIZE >> PAGE_SHIFT); } } EXPORT_SYMBOL(__page_table_check_pud_clear); @@ -223,7 +223,7 @@ void __page_table_check_pmd_set(struct mm_struct *mm, unsigned long addr, __page_table_check_pmd_clear(mm, addr, *pmdp); if (pmd_user_accessible_page(pmd)) { page_table_check_set(mm, addr, pmd_pfn(pmd), - PMD_PAGE_SIZE >> PAGE_SHIFT, + PMD_SIZE >> PAGE_SHIFT, pmd_write(pmd)); } } @@ -238,7 +238,7 @@ void __page_table_check_pud_set(struct mm_struct *mm, unsigned long addr, __page_table_check_pud_clear(mm, addr, *pudp); if (pud_user_accessible_page(pud)) { page_table_check_set(mm, addr, pud_pfn(pud), - PUD_PAGE_SIZE >> PAGE_SHIFT, + PUD_SIZE >> PAGE_SHIFT, pud_write(pud)); } } -- Gitee From 21bdebbb0b88bfbfe4f50e31582c5467be34ef78 Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Fri, 16 Sep 2022 23:57:28 +0800 Subject: [PATCH 09/13] mm: page_table_check: move pxx_user_accessible_page into x86 mainline inclusion from mainline-v6.0 commit e5a554014618308f046af99ab9c950165ed6cb11 category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e5a554014618308f046af99ab9c950165ed6cb11 ------------------------------------------------- The pxx_user_accessible_page() checks the PTE bit, it's architecture-specific code, move them into x86's pgtable.h. These helpers are being moved out to make the page table check framework platform independent. Link: https://lkml.kernel.org/r/20220507110114.4128854-3-tongtiangen@huawei.com Signed-off-by: Kefeng Wang Signed-off-by: Tong Tiangen Acked-by: Pasha Tatashin Reviewed-by: Anshuman Khandual Cc: Borislav Petkov Cc: Catalin Marinas Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Will Deacon Signed-off-by: Andrew Morton (cherry picked from commit e5a554014618308f046af99ab9c950165ed6cb11) Signed-off-by: Kefeng Wang Signed-off-by: Zeng Zhimin --- arch/x86/include/asm/pgtable.h | 17 +++++++++++++++++ mm/page_table_check.c | 17 ----------------- 2 files changed, 17 insertions(+), 17 deletions(-) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 8fdb8d84d122..aefcc77b4289 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -1428,6 +1428,23 @@ static inline bool arch_faults_on_old_pte(void) return false; } +#ifdef CONFIG_PAGE_TABLE_CHECK +static inline bool pte_user_accessible_page(pte_t pte) +{ + return (pte_val(pte) & _PAGE_PRESENT) && (pte_val(pte) & _PAGE_USER); +} + +static inline bool pmd_user_accessible_page(pmd_t pmd) +{ + return pmd_leaf(pmd) && (pmd_val(pmd) & _PAGE_PRESENT) && (pmd_val(pmd) & _PAGE_USER); +} + +static inline bool pud_user_accessible_page(pud_t pud) +{ + return pud_leaf(pud) && (pud_val(pud) & _PAGE_PRESENT) && (pud_val(pud) & _PAGE_USER); +} +#endif + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_PGTABLE_H */ diff --git a/mm/page_table_check.c b/mm/page_table_check.c index 4ef604d14d2f..d2d3b8c2e3e9 100644 --- a/mm/page_table_check.c +++ b/mm/page_table_check.c @@ -56,23 +56,6 @@ static struct page_table_check *get_page_table_check(struct page_ext *page_ext) return (void *)(page_ext) + page_table_check_ops.offset; } -static inline bool pte_user_accessible_page(pte_t pte) -{ - return (pte_val(pte) & _PAGE_PRESENT) && (pte_val(pte) & _PAGE_USER); -} - -static inline bool pmd_user_accessible_page(pmd_t pmd) -{ - return pmd_leaf(pmd) && (pmd_val(pmd) & _PAGE_PRESENT) && - (pmd_val(pmd) & _PAGE_USER); -} - -static inline bool pud_user_accessible_page(pud_t pud) -{ - return pud_leaf(pud) && (pud_val(pud) & _PAGE_PRESENT) && - (pud_val(pud) & _PAGE_USER); -} - /* * An enty is removed from the page table, decrement the counters for that page * verify that it is of correct type and counters do not become negative. -- Gitee From e080a3b6b056a2729d07ce26b51c28b926c144c1 Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Sat, 17 Sep 2022 00:04:46 +0800 Subject: [PATCH 10/13] mm: page_table_check: add hooks to public helpers mainline inclusion from mainline-v6.0 commit de8c8e52836d0082188508548d0b939f49f7f0e6 category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=de8c8e52836d0082188508548d0b939f49f7f0e6 ------------------------------------------------- Move ptep_clear() to the include/linux/pgtable.h and add page table check relate hooks to some helpers, it's prepare for support page table check feature on new architecture. Optimize the implementation of ptep_clear(), page table hooks added page table check stubs, the interface control should be at stubs, there is no rationale for doing a IS_ENABLED() check here. For architectures that do not enable CONFIG_PAGE_TABLE_CHECK, they will call a fallback page table check stubs[1] when getting their page table helpers[2] in include/linux/pgtable.h. [1] page table check stubs defined in include/linux/page_table_check.h [2] ptep_clear() ptep_get_and_clear() pmdp_huge_get_and_clear() pudp_huge_get_and_clear() Link: https://lkml.kernel.org/r/20220507110114.4128854-4-tongtiangen@huawei.com Signed-off-by: Tong Tiangen Acked-by: Pasha Tatashin Cc: Anshuman Khandual Cc: Borislav Petkov Cc: Catalin Marinas Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Kefeng Wang Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Will Deacon Signed-off-by: Andrew Morton (cherry picked from commit de8c8e52836d0082188508548d0b939f49f7f0e6) Signed-off-by: Kefeng Wang Signed-off-by: Zeng Zhimin --- arch/x86/include/asm/pgtable.h | 10 ---------- include/linux/pgtable.h | 23 +++++++++++++++-------- 2 files changed, 15 insertions(+), 18 deletions(-) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index aefcc77b4289..028d82290dbc 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -1075,16 +1075,6 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, return pte; } -#define __HAVE_ARCH_PTEP_CLEAR -static inline void ptep_clear(struct mm_struct *mm, unsigned long addr, - pte_t *ptep) -{ - if (IS_ENABLED(CONFIG_PAGE_TABLE_CHECK)) - ptep_get_and_clear(mm, addr, ptep); - else - pte_clear(mm, addr, ptep); -} - #define __HAVE_ARCH_PTEP_SET_WRPROTECT static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index b090887e4ba4..7986501bb71e 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -12,6 +12,7 @@ #include #include #include +#include #if 5 - defined(__PAGETABLE_P4D_FOLDED) - defined(__PAGETABLE_PUD_FOLDED) - \ defined(__PAGETABLE_PMD_FOLDED) != CONFIG_PGTABLE_LEVELS @@ -248,10 +249,19 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, { pte_t pte = *ptep; pte_clear(mm, address, ptep); + page_table_check_pte_clear(mm, address, pte); return pte; } #endif +#ifndef __HAVE_ARCH_PTEP_CLEAR +static inline void ptep_clear(struct mm_struct *mm, unsigned long addr, + pte_t *ptep) +{ + ptep_get_and_clear(mm, addr, ptep); +} +#endif + #ifndef __HAVE_ARCH_PTEP_GET static inline pte_t ptep_get(pte_t *ptep) { @@ -266,7 +276,10 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, pmd_t *pmdp) { pmd_t pmd = *pmdp; + pmd_clear(pmdp); + page_table_check_pmd_clear(mm, address, pmd); + return pmd; } #endif /* __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR */ @@ -278,6 +291,8 @@ static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm, pud_t pud = *pudp; pud_clear(pudp); + page_table_check_pud_clear(mm, address, pud); + return pud; } #endif /* __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR */ @@ -303,14 +318,6 @@ static inline pud_t pudp_huge_get_and_clear_full(struct mm_struct *mm, #endif #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ -#ifndef __HAVE_ARCH_PTEP_CLEAR -static inline void ptep_clear(struct mm_struct *mm, unsigned long addr, - pte_t *ptep) -{ - pte_clear(mm, addr, ptep); -} -#endif - #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, unsigned long address, pte_t *ptep, -- Gitee From b1f9c5a0696040f69f83857aec92da52bfe08484 Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Sat, 17 Sep 2022 00:09:08 +0800 Subject: [PATCH 11/13] mm: remove __HAVE_ARCH_PTEP_CLEAR in pgtable.h mainline inclusion from mainline-v6.0 commit 2e7dc2b632a324c670ff11dd6c84d711043c683f category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2e7dc2b632a324c670ff11dd6c84d711043c683f ------------------------------------------------- Currently, there is no architecture definition __HAVE_ARCH_PTEP_CLEAR, Generic ptep_clear() is the only definition for all architecture, So drop the "#ifndef __HAVE_ARCH_PTEP_CLEAR". Link: https://lkml.kernel.org/r/20220507110114.4128854-5-tongtiangen@huawei.com Signed-off-by: Tong Tiangen Suggested-by: Anshuman Khandual Cc: Borislav Petkov Cc: Catalin Marinas Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Kefeng Wang Cc: Palmer Dabbelt Cc: Pasha Tatashin Cc: Paul Walmsley Cc: Will Deacon Signed-off-by: Andrew Morton (cherry picked from commit 2e7dc2b632a324c670ff11dd6c84d711043c683f) Signed-off-by: Kefeng Wang Signed-off-by: Zeng Zhimin --- include/linux/pgtable.h | 2 -- 1 file changed, 2 deletions(-) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 7986501bb71e..84b92ff884c1 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -254,13 +254,11 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, } #endif -#ifndef __HAVE_ARCH_PTEP_CLEAR static inline void ptep_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { ptep_get_and_clear(mm, addr, ptep); } -#endif #ifndef __HAVE_ARCH_PTEP_GET static inline pte_t ptep_get(pte_t *ptep) -- Gitee From 4c6422727a3bd7e8beae2797a1c8d99731bd1d81 Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Sat, 17 Sep 2022 00:17:00 +0800 Subject: [PATCH 12/13] arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK mainline inclusion from mainline-v6.0 commit 42b2547137f5c974bb1bfd657c869fe96b96d86f category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=42b2547137f5c974bb1bfd657c869fe96b96d86f ------------------------------------------------- As commit d283d422c6c4 ("x86: mm: add x86_64 support for page table check") , enable ARCH_SUPPORTS_PAGE_TABLE_CHECK on arm64. Add additional page table check stubs for page table helpers, these stubs can be used to check the existing page table entries. Link: https://lkml.kernel.org/r/20220507110114.4128854-6-tongtiangen@huawei.com Signed-off-by: Kefeng Wang Signed-off-by: Tong Tiangen Reviewed-by: Pasha Tatashin Acked-by: Catalin Marinas Cc: Anshuman Khandual Cc: Borislav Petkov Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Will Deacon Signed-off-by: Andrew Morton (cherry picked from commit 42b2547137f5c974bb1bfd657c869fe96b96d86f) Signed-off-by: Kefeng Wang Signed-off-by: Zeng Zhimin --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/pgtable.h | 61 ++++++++++++++++++++++++++++---- 2 files changed, 56 insertions(+), 6 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 8f47907b4033..0e09962f667c 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -78,6 +78,7 @@ config ARM64 select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG) select ARCH_SUPPORTS_NUMA_BALANCING + select ARCH_SUPPORTS_PAGE_TABLE_CHECK select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT select ARCH_WANT_DEFAULT_BPF_JIT select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index ab2443900f4e..4f94892e312f 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -35,6 +35,7 @@ #include #include #include +#include #ifdef CONFIG_TRANSPARENT_HUGEPAGE #define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE @@ -98,6 +99,7 @@ static inline pteval_t __phys_to_pte_val(phys_addr_t phys) #define pte_young(pte) (!!(pte_val(pte) & PTE_AF)) #define pte_special(pte) (!!(pte_val(pte) & PTE_SPECIAL)) #define pte_write(pte) (!!(pte_val(pte) & PTE_WRITE)) +#define pte_user(pte) (!!(pte_val(pte) & PTE_USER)) #define pte_user_exec(pte) (!(pte_val(pte) & PTE_UXN)) #define pte_cont(pte) (!!(pte_val(pte) & PTE_CONT)) #define pte_devmap(pte) (!!(pte_val(pte) & PTE_DEVMAP)) @@ -314,8 +316,8 @@ static inline void __check_racy_pte_update(struct mm_struct *mm, pte_t *ptep, __func__, pte_val(old_pte), pte_val(pte)); } -static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, - pte_t *ptep, pte_t pte) +static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, pte_t pte) { if (pte_present(pte) && pte_user_exec(pte) && !pte_special(pte)) __sync_icache_dcache(pte); @@ -329,6 +331,13 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, set_pte(ptep, pte); } +static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, pte_t pte) +{ + page_table_check_pte_set(mm, addr, ptep, pte); + return __set_pte_at(mm, addr, ptep, pte); +} + /* * Huge pte definitions. */ @@ -424,6 +433,8 @@ static inline int pmd_trans_huge(pmd_t pmd) #define pmd_dirty(pmd) pte_dirty(pmd_pte(pmd)) #define pmd_young(pmd) pte_young(pmd_pte(pmd)) #define pmd_valid(pmd) pte_valid(pmd_pte(pmd)) +#define pmd_user(pmd) pte_user(pmd_pte(pmd)) +#define pmd_user_exec(pmd) pte_user_exec(pmd_pte(pmd)) #define pmd_wrprotect(pmd) pte_pmd(pte_wrprotect(pmd_pte(pmd))) #define pmd_mkold(pmd) pte_pmd(pte_mkold(pmd_pte(pmd))) #define pmd_mkwrite(pmd) pte_pmd(pte_mkwrite(pmd_pte(pmd))) @@ -470,8 +481,19 @@ static inline pmd_t pmd_mkdevmap(pmd_t pmd) #define pud_pfn(pud) ((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT) #define pfn_pud(pfn,prot) __pud(__phys_to_pud_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)) -#define set_pmd_at(mm, addr, pmdp, pmd) set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd)) -#define set_pud_at(mm, addr, pudp, pud) set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud)) +static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, + pmd_t *pmdp, pmd_t pmd) +{ + page_table_check_pmd_set(mm, addr, pmdp, pmd); + return __set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd)); +} + +static inline void set_pud_at(struct mm_struct *mm, unsigned long addr, + pud_t *pudp, pud_t pud) +{ + page_table_check_pud_set(mm, addr, pudp, pud); + return __set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud)); +} #define __p4d_to_phys(p4d) __pte_to_phys(p4d_pte(p4d)) #define __phys_to_p4d_val(phys) __phys_to_pte_val(phys) @@ -609,6 +631,24 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd) #define pud_present(pud) pte_present(pud_pte(pud)) #define pud_leaf(pud) (pud_present(pud) && !pud_table(pud)) #define pud_valid(pud) pte_valid(pud_pte(pud)) +#define pud_user(pud) pte_user(pud_pte(pud)) + +#ifdef CONFIG_PAGE_TABLE_CHECK +static inline bool pte_user_accessible_page(pte_t pte) +{ + return pte_present(pte) && (pte_user(pte) || pte_user_exec(pte)); +} + +static inline bool pmd_user_accessible_page(pmd_t pmd) +{ + return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); +} + +static inline bool pud_user_accessible_page(pud_t pud) +{ + return pud_present(pud) && pud_user(pud); +} +#endif static inline void set_pud(pud_t *pudp, pud_t pud) { @@ -842,7 +882,11 @@ static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma, static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long address, pte_t *ptep) { - return __pte(xchg_relaxed(&pte_val(*ptep), 0)); + pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0)); + + page_table_check_pte_clear(mm, address, pte); + + return pte; } #ifdef CONFIG_TRANSPARENT_HUGEPAGE @@ -850,7 +894,11 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, unsigned long address, pmd_t *pmdp) { - return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp)); + pmd_t pmd = __pmd(xchg_relaxed(&pmd_val(*pmdp), 0)); + + page_table_check_pmd_clear(mm, address, pmd); + + return pmd; } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ @@ -884,6 +932,7 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm, static inline pmd_t pmdp_establish(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp, pmd_t pmd) { + page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd); return __pmd(xchg_relaxed(&pmd_val(*pmdp), pmd_val(pmd))); } #endif -- Gitee From 9846ae4c121a47845a963f23f29ac026c6c5f684 Mon Sep 17 00:00:00 2001 From: AlieZ22 <820460891@qq.com> Date: Sat, 17 Sep 2022 00:25:21 +0800 Subject: [PATCH 13/13] arm64/mm: fix page table check compile error for CONFIG_PGTABLE_LEVELS=2 mainline inclusion from mainline-v6.0 commit ed928a3402d8a24a70c242c63109c069a7b1f3ab category: feature bugzilla: https://gitee.com/openeuler/open-source-summer/issues/I56FG1?from=project-issue CVE: N/A Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ed928a3402d8a24a70c242c63109c069a7b1f3ab ------------------------------------------------- If CONFIG_PGTABLE_LEVELS=2 and CONFIG_ARCH_SUPPORTS_PAGE_TABLE_CHECK=y, then we trigger a compile error: error: implicit declaration of function 'pte_user_accessible_page' Move the definition of page table check helper out of branch CONFIG_PGTABLE_LEVELS > 2 Link: https://lkml.kernel.org/r/20220517074548.2227779-3-tongtiangen@huawei.com Fixes: daf214c14dbe ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") Signed-off-by: Tong Tiangen Acked-by: Catalin Marinas Cc: Anshuman Khandual Cc: Pasha Tatashin Cc: Anshuman Khandual Cc: Will Deacon Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Arnd Bergmann Cc: Guohanjun Cc: Xie XiuQi Cc: kernel test robot Signed-off-by: Andrew Morton (cherry picked from commit ed928a3402d8a24a70c242c63109c069a7b1f3ab) Signed-off-by: Kefeng Wang Signed-off-by: Zeng Zhimin --- arch/arm64/include/asm/pgtable.h | 34 ++++++++++++++++---------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 4f94892e312f..e9ef73849896 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -633,23 +633,6 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd) #define pud_valid(pud) pte_valid(pud_pte(pud)) #define pud_user(pud) pte_user(pud_pte(pud)) -#ifdef CONFIG_PAGE_TABLE_CHECK -static inline bool pte_user_accessible_page(pte_t pte) -{ - return pte_present(pte) && (pte_user(pte) || pte_user_exec(pte)); -} - -static inline bool pmd_user_accessible_page(pmd_t pmd) -{ - return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); -} - -static inline bool pud_user_accessible_page(pud_t pud) -{ - return pud_present(pud) && pud_user(pud); -} -#endif - static inline void set_pud(pud_t *pudp, pud_t pud) { #ifdef __PAGETABLE_PUD_FOLDED @@ -821,6 +804,23 @@ static inline int pgd_devmap(pgd_t pgd) } #endif +#ifdef CONFIG_PAGE_TABLE_CHECK +static inline bool pte_user_accessible_page(pte_t pte) +{ + return pte_present(pte) && (pte_user(pte) || pte_user_exec(pte)); +} + +static inline bool pmd_user_accessible_page(pmd_t pmd) +{ + return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); +} + +static inline bool pud_user_accessible_page(pud_t pud) +{ + return pud_present(pud) && pud_user(pud); +} +#endif + /* * Atomic pte/pmd modifications. */ -- Gitee