diff options
| author | Liu Shixin <liushixin2@huawei.com> | 2022-11-17 15:56:01 +0800 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2022-11-18 19:31:54 +0000 |
| commit | 5b47348fc0b18a78c96f8474cc90b7525ad1bbfe (patch) | |
| tree | 7c64e9f33941427be614ad8d04864560ac79716c /arch/arm64/include/asm/pgtable.h | |
| parent | 2598ac6ec493566105f8a1029aa9de36ba6946ca (diff) | |
| download | linux-5b47348fc0b18a78c96f8474cc90b7525ad1bbfe.tar.bz2 | |
arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud
The page table check trigger BUG_ON() unexpectedly when collapse hugepage:
------------[ cut here ]------------
kernel BUG at mm/page_table_check.c:82!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750
Hardware name: linux,dummy-virt (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : page_table_check_clear.isra.0+0x258/0x3f0
lr : page_table_check_clear.isra.0+0x240/0x3f0
[...]
Call trace:
page_table_check_clear.isra.0+0x258/0x3f0
__page_table_check_pmd_clear+0xbc/0x108
pmdp_collapse_flush+0xb0/0x160
collapse_huge_page+0xa08/0x1080
hpage_collapse_scan_pmd+0xf30/0x1590
khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8
khugepaged+0x338/0x518
kthread+0x278/0x2f8
ret_from_fork+0x10/0x20
[...]
Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it
decrease file_map_count for a non-leaf pmd comes from collapse_huge_page().
and so trigger BUG_ON() unexpectedly.
Fix this problem by using pmd_leaf() insteal of pmd_present() in
pmd_user_accessible_page(). Moreover, use pud_leaf() for
pud_user_accessible_page() too.
Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK")
Reported-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20221117075602.2904324-2-liushixin2@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/pgtable.h')
| -rw-r--r-- | arch/arm64/include/asm/pgtable.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 71a1af42f0e8..edf6625ce965 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) static inline bool pmd_user_accessible_page(pmd_t pmd) { - return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); + return pmd_leaf(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); + return pud_leaf(pud) && pud_user(pud); } #endif |