summaryrefslogtreecommitdiff
path: root/arch/arm64
diff options
context:
space:
mode:
authorLiu Shixin <liushixin2@huawei.com>2022-11-21 10:36:08 +0300
committerWill Deacon <will@kernel.org>2023-01-05 18:04:49 +0300
commit74c2f81054510d45b813548cb0a1c4ebf87cdd5f (patch)
tree2921211b7cfebe60cd9fef72601580f6a2e5d3c6 /arch/arm64
parent1b929c02afd37871d5afb9d498426f83432e71c2 (diff)
downloadlinux-74c2f81054510d45b813548cb0a1c4ebf87cdd5f.tar.xz
arm64/mm: fix incorrect file_map_count for invalid pmd
The page table check trigger BUG_ON() unexpectedly when split hugepage: ------------[ cut here ]------------ kernel BUG at mm/page_table_check.c:119! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 Hardware name: linux,dummy-virt (DT) pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : page_table_check_set.isra.0+0x398/0x468 lr : page_table_check_set.isra.0+0x1c0/0x468 [...] Call trace: page_table_check_set.isra.0+0x398/0x468 __page_table_check_pte_set+0x160/0x1c0 __split_huge_pmd_locked+0x900/0x1648 __split_huge_pmd+0x28c/0x3b8 unmap_page_range+0x428/0x858 unmap_single_vma+0xf4/0x1c8 zap_page_range+0x2b0/0x410 madvise_vma_behavior+0xc44/0xe78 do_madvise+0x280/0x698 __arm64_sys_madvise+0x90/0xe8 invoke_syscall.constprop.0+0xdc/0x1d8 do_el0_svc+0xf4/0x3f8 el0_svc+0x58/0x120 el0t_64_sync_handler+0xb8/0xc0 el0t_64_sync+0x19c/0x1a0 [...] On arm64, pmd_leaf() will return true even if the pmd is invalid due to pmd_present_invalid() check. So in pmdp_invalidate() the file_map_count will not only decrease once but also increase once. Then in set_pte_at(), the file_map_count increase again, and so trigger BUG_ON() unexpectedly. Add !pmd_present_invalid() check in pmd_user_accessible_page() to fix the problem. 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> Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20221121073608.4183459-1-liushixin2@huawei.com Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/include/asm/pgtable.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index b4bbeed80fb6..67fc6fdb03fd 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -862,7 +862,7 @@ static inline bool pte_user_accessible_page(pte_t pte)
static inline bool pmd_user_accessible_page(pmd_t pmd)
{
- return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd));
+ return pmd_leaf(pmd) && !pmd_present_invalid(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd));
}
static inline bool pud_user_accessible_page(pud_t pud)