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authorPasha Tatashin <pasha.tatashin@soleen.com>2022-02-04 07:49:10 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-02-04 20:25:04 +0300
commitfb5222aae64fe25e5f3ebefde8214dcf3ba33ca5 (patch)
treee96005f52c0e4fcee8129306dd00e776db92c6b2 /mm
parenta85468b766d3bc17c8b17ed23a36ef6469340bb2 (diff)
downloadlinux-fb5222aae64fe25e5f3ebefde8214dcf3ba33ca5.tar.xz
mm/debug_vm_pgtable: remove pte entry from the page table
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>
Diffstat (limited to 'mm')
-rw-r--r--mm/debug_vm_pgtable.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index a7ac97c76762..db2abd9e415b 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -171,6 +171,8 @@ static void __init pte_advanced_tests(struct pgtable_debug_args *args)
ptep_test_and_clear_young(args->vma, args->vaddr, args->ptep);
pte = ptep_get(args->ptep);
WARN_ON(pte_young(pte));
+
+ ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1);
}
static void __init pte_savedwrite_tests(struct pgtable_debug_args *args)