diff options
| author | Pasha Tatashin <[email protected]> | 2022-02-03 20:49:10 -0800 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2022-02-04 09:25:04 -0800 |
| commit | fb5222aae64fe25e5f3ebefde8214dcf3ba33ca5 (patch) | |
| tree | e96005f52c0e4fcee8129306dd00e776db92c6b2 | |
| parent | a85468b766d3bc17c8b17ed23a36ef6469340bb2 (diff) | |
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/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: a5c3b9ffb0f4 ("mm/debug_vm_pgtable: add tests validating advanced arch page table helpers")
Signed-off-by: Pasha Tatashin <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Tested-by: Zi Yan <[email protected]>
Acked-by: David Rientjes <[email protected]>
Reviewed-by: Anshuman Khandual <[email protected]>
Cc: Paul Turner <[email protected]>
Cc: Wei Xu <[email protected]>
Cc: Greg Thelen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: <[email protected]> [5.9+]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | mm/debug_vm_pgtable.c | 2 |
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) |