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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
arch arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud 2022-11-18 19:31:54 +00:00
block block-6.1-2022-11-05 2022-11-05 09:02:28 -07:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto treewide: use get_random_bytes() when possible 2022-10-11 17:42:58 -06:00
Documentation Kbuild fixes for v6.1 (2nd) 2022-11-06 12:23:10 -08:00
drivers cxl fixes for 6.1-rc4 2022-11-06 13:09:52 -08:00
fs Fix a number of bug fixes, including some regressions, the most 2022-11-06 10:30:29 -08:00
include kernel hardening fix for v6.1-rc4 2022-11-04 14:46:45 -07:00
init init: Kconfig: fix spelling mistake "satify" -> "satisfy" 2022-10-20 21:27:22 -07:00
io_uring io_uring: unlock if __io_run_local_work locked inside 2022-10-27 09:52:12 -06:00
ipc ipc/msg.c: fix percpu_counter use after free 2022-10-28 13:37:22 -07:00
kernel - Add Cooper Lake's stepping to the PEBS guest/host events isolation 2022-11-06 12:41:32 -08:00
lib Networking fixes for 6.1-rc4, including fixes from bluetooth and 2022-11-03 10:51:59 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mmap: fix remap_file_pages() regression 2022-10-28 13:37:23 -07:00
net Networking fixes for 6.1-rc4, including fixes from bluetooth and 2022-11-03 10:51:59 -07:00
rust Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
samples VFIO updates for v6.1-rc1 2022-10-12 14:46:48 -07:00
scripts kconfig: fix segmentation fault in menuconfig search 2022-11-02 17:32:05 +09:00
security lsm/stable-6.1 PR 20221031 2022-10-31 12:09:42 -07:00
sound ALSA: aoa: Fix I2S device accounting 2022-10-27 08:53:08 +02:00
tools cxl fixes for 6.1-rc4 2022-11-06 13:09:52 -08:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt Merge tag 'kvmarm-fixes-6.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD 2022-11-06 03:30:49 -05:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap mailmap: update email for Qais Yousef 2022-10-20 21:27:21 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS ARM: SoC fixes for 6.1, part 2 2022-11-04 14:13:12 -07:00
Makefile Linux 6.1-rc4 2022-11-06 15:07:11 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.