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Aneesh Kumar K.V db110a99d3 mm/hugetlb: fix kernel crash with hugetlb mremap
This fixes the below crash:

  kernel BUG at include/linux/mm.h:2373!
  cpu 0x5d: Vector: 700 (Program Check) at [c00000003c6e76e0]
      pc: c000000000581a54: pmd_to_page+0x54/0x80
      lr: c00000000058d184: move_hugetlb_page_tables+0x4e4/0x5b0
      sp: c00000003c6e7980
     msr: 9000000000029033
    current = 0xc00000003bd8d980
    paca    = 0xc000200fff610100   irqmask: 0x03   irq_happened: 0x01
      pid   = 9349, comm = hugepage-mremap
  kernel BUG at include/linux/mm.h:2373!
    move_hugetlb_page_tables+0x4e4/0x5b0 (link register)
    move_hugetlb_page_tables+0x22c/0x5b0 (unreliable)
    move_page_tables+0xdbc/0x1010
    move_vma+0x254/0x5f0
    sys_mremap+0x7c0/0x900
    system_call_exception+0x160/0x2c0

the kernel can't use huge_pte_offset before it set the pte entry because
a page table lookup check for huge PTE bit in the page table to
differentiate between a huge pte entry and a pointer to pte page.  A
huge_pte_alloc won't mark the page table entry huge and hence kernel
should not use huge_pte_offset after a huge_pte_alloc.

Link: https://lkml.kernel.org/r/20220211063221.99293-1-aneesh.kumar@linux.ibm.com
Fixes: 550a7d60bd ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00
arch x86 host: 2022-02-24 14:05:49 -08:00
block block: clear iocb->private in blkdev_bio_end_io_async() 2022-02-22 06:59:49 -07:00
certs certs: Fix build error when CONFIG_MODULE_SIG_KEY is empty 2022-01-23 00:08:44 +09:00
crypto crypto: af_alg - get rid of alg_memory_allocated 2022-02-15 14:29:04 +00:00
Documentation x86 host: 2022-02-24 14:05:49 -08:00
drivers Char/Misc driver fixes for 5.17-rc6 2022-02-25 12:12:06 -08:00
fs io_uring-5.17-2022-02-23 2022-02-24 11:08:15 -08:00
include Char/Misc driver fixes for 5.17-rc6 2022-02-25 12:12:06 -08:00
init lib/stackdepot: allow optional init and stack_table allocation by kvmalloc() 2022-01-22 08:33:37 +02:00
ipc ipc/sem: do not sleep with a spin lock held 2022-02-04 09:25:05 -08:00
kernel Networking fixes for 5.17-rc6, including fixes from bpf and netfilter. 2022-02-24 12:45:32 -08:00
lib Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-02-22 10:31:53 -08:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/hugetlb: fix kernel crash with hugetlb mremap 2022-02-26 09:51:17 -08:00
net ping: remove pr_err from ping_lookup 2022-02-24 09:18:29 -08:00
samples samples/seccomp: Adjust sample to also provide kill option 2022-02-10 19:09:12 -08:00
scripts kconfig: fix failing to generate auto.conf 2022-02-12 23:24:19 +09:00
security selinux/stable-5.17 PR 20220223 2022-02-23 17:19:55 -08:00
sound ASoC: intel: skylake: Set max DMA segment size 2022-02-17 09:39:44 +01:00
tools perf tools fixes for v5.17: 3rd batch 2022-02-24 14:36:38 -08:00
usr kbuild: remove include/linux/cyclades.h from header file check 2022-01-27 08:51:08 +01:00
virt KVM: Fix lockdep false negative during host resume 2022-02-17 09:52:50 -05:00
.clang-format genirq/msi: Make interrupt allocation less convoluted 2021-12-16 22:22:20 +01:00
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.mailmap mailmap: update Christian Brauner's email address 2022-02-01 11:21:31 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Removing Ohad from remoteproc/rpmsg maintenance 2021-12-08 10:09:40 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: add sysctl-next git tree 2022-02-26 09:51:17 -08:00
Makefile Linux 5.17-rc5 2022-02-20 13:07:20 -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.