OpenCloudOS-Kernel/arch/arm64
Liu Shixin 5b47348fc0 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: 42b2547137 ("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>
2022-11-18 19:31:54 +00:00
..
boot Armv8 Juno fix for v6.1 2022-11-02 21:58:46 +01:00
configs This update includes the following changes: 2022-10-10 13:04:25 -07:00
crypto This update includes the following changes: 2022-10-10 13:04:25 -07:00
hyperv hyperv: simplify and rename generate_guest_id 2022-09-28 13:36:56 +00:00
include arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud 2022-11-18 19:31:54 +00:00
kernel arm64: ftrace: Define ftrace_stub_graph only with FUNCTION_GRAPH_TRACER 2022-11-14 12:28:52 +00:00
kvm KVM: arm64: Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHE 2022-11-01 15:56:52 +00:00
lib Networking changes for 6.0. 2022-08-03 16:29:08 -07:00
mm arm64: efi: Recover from synchronous exceptions occurring in firmware 2022-11-03 18:01:15 +01:00
net bpf: arm64: No support of struct argument in trampoline programs 2022-09-06 19:51:14 -07:00
tools arm64/sysreg: Fix typo in SCTR_EL1.SPINTMASK 2022-10-07 14:30:11 +01:00
xen
Kbuild
Kconfig arm64 fixes: 2022-10-14 12:38:03 -07:00
Kconfig.debug
Kconfig.platforms ARM: SoC code changes for 6.1 2022-10-06 11:22:25 -07:00
Makefile Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00