| From fb5222aae64fe25e5f3ebefde8214dcf3ba33ca5 Mon Sep 17 00:00:00 2001 |
| From: Pasha Tatashin <pasha.tatashin@soleen.com> |
| Date: Thu, 3 Feb 2022 20:49:10 -0800 |
| Subject: mm/debug_vm_pgtable: remove pte entry from the page table |
| |
| From: Pasha Tatashin <pasha.tatashin@soleen.com> |
| |
| commit fb5222aae64fe25e5f3ebefde8214dcf3ba33ca5 upstream. |
| |
| Patch series "page table check fixes and cleanups", v5. |
| |
| This patch (of 4): |
| |
| The pte entry that is used in pte_advanced_tests() is never removed from |
| the page table at the end of the test. |
| |
| The issue is detected by page_table_check, to repro compile kernel with |
| the following configs: |
| |
| CONFIG_DEBUG_VM_PGTABLE=y |
| CONFIG_PAGE_TABLE_CHECK=y |
| CONFIG_PAGE_TABLE_CHECK_ENFORCED=y |
| |
| During the boot the following BUG is printed: |
| |
| debug_vm_pgtable: [debug_vm_pgtable ]: Validating architecture page table helpers |
| ------------[ cut here ]------------ |
| kernel BUG at mm/page_table_check.c:162! |
| invalid opcode: 0000 [#1] PREEMPT SMP PTI |
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.16.0-11413-g2c271fe77d52 #3 |
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 |
| ... |
| |
| The entry should be properly removed from the page table before the page |
| is released to the free list. |
| |
| Link: https://lkml.kernel.org/r/20220131203249.2832273-1-pasha.tatashin@soleen.com |
| Link: https://lkml.kernel.org/r/20220131203249.2832273-2-pasha.tatashin@soleen.com |
| Fixes: a5c3b9ffb0f4 ("mm/debug_vm_pgtable: add tests validating advanced arch page table helpers") |
| Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> |
| Reviewed-by: Zi Yan <ziy@nvidia.com> |
| Tested-by: Zi Yan <ziy@nvidia.com> |
| Acked-by: David Rientjes <rientjes@google.com> |
| Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> |
| Cc: Paul Turner <pjt@google.com> |
| Cc: Wei Xu <weixugc@google.com> |
| Cc: Greg Thelen <gthelen@google.com> |
| Cc: Ingo Molnar <mingo@redhat.com> |
| Cc: Will Deacon <will@kernel.org> |
| Cc: Mike Rapoport <rppt@kernel.org> |
| Cc: Dave Hansen <dave.hansen@linux.intel.com> |
| Cc: H. Peter Anvin <hpa@zytor.com> |
| Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> |
| Cc: Jiri Slaby <jirislaby@kernel.org> |
| Cc: Muchun Song <songmuchun@bytedance.com> |
| Cc: Hugh Dickins <hughd@google.com> |
| Cc: <stable@vger.kernel.org> [5.9+] |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| mm/debug_vm_pgtable.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/mm/debug_vm_pgtable.c |
| +++ b/mm/debug_vm_pgtable.c |
| @@ -128,6 +128,8 @@ static void __init pte_advanced_tests(st |
| ptep_test_and_clear_young(vma, vaddr, ptep); |
| pte = ptep_get(ptep); |
| WARN_ON(pte_young(pte)); |
| + |
| + ptep_get_and_clear_full(mm, vaddr, ptep, 1); |
| } |
| |
| static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot) |