Liu Shixin 2a57d83c78 mm/hwpoison: clear MF_COUNT_INCREASED before retrying get_any_page()
Hulk Robot reported a panic in put_page_testzero() when testing
madvise() with MADV_SOFT_OFFLINE.  The BUG() is triggered when retrying
get_any_page().  This is because we keep MF_COUNT_INCREASED flag in
second try but the refcnt is not increased.

    page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0)
    ------------[ cut here ]------------
    kernel BUG at include/linux/mm.h:737!
    invalid opcode: 0000 [#1] PREEMPT SMP
    CPU: 5 PID: 2135 Comm: sshd Tainted: G    B             5.16.0-rc6-dirty #373
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
    RIP: release_pages+0x53f/0x840
    Call Trace:
      free_pages_and_swap_cache+0x64/0x80
      tlb_flush_mmu+0x6f/0x220
      unmap_page_range+0xe6c/0x12c0
      unmap_single_vma+0x90/0x170
      unmap_vmas+0xc4/0x180
      exit_mmap+0xde/0x3a0
      mmput+0xa3/0x250
      do_exit+0x564/0x1470
      do_group_exit+0x3b/0x100
      __do_sys_exit_group+0x13/0x20
      __x64_sys_exit_group+0x16/0x20
      do_syscall_64+0x34/0x80
      entry_SYSCALL_64_after_hwframe+0x44/0xae
    Modules linked in:
    ---[ end trace e99579b570fe0649 ]---
    RIP: 0010:release_pages+0x53f/0x840

Link: https://lkml.kernel.org/r/20211221074908.3910286-1-liushixin2@huawei.com
Fixes: b94e02822deb ("mm,hwpoison: try to narrow window race for free pages")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-25 12:20:56 -08:00
2021-12-19 12:38:53 -08:00
2021-11-13 15:32:30 -08:00
2021-12-22 10:11:17 -08:00
2021-12-21 12:02:36 -08:00
2021-12-10 11:43:00 -08:00
2021-12-19 14:14:33 -08:00

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.
Description
Linux kernel stable tree
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