mm: hwpoison: support recovery from HugePage copy-on-write faults

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copy-on-write of hugetlb user pages with uncorrectable errors will result
in a kernel crash.  This is because the copy is performed in kernel mode
and in general we can not handle accessing memory with such errors while
in kernel mode.  Commit a873dfe103 ("mm, hwpoison: try to recover from
copy-on write faults") introduced the routine copy_user_highpage_mc() to
gracefully handle copying of user pages with uncorrectable errors. 
However, the separate hugetlb copy-on-write code paths were not modified
as part of commit a873dfe103.

Modify hugetlb copy-on-write code paths to use copy_mc_user_highpage() so
that they can also gracefully handle uncorrectable errors in user pages. 
This involves changing the hugetlb specific routine
copy_user_large_folio() from type void to int so that it can return an
error.  Modify the hugetlb userfaultfd code in the same way so that it can
return -EHWPOISON if it encounters an uncorrectable error.

Link: https://lkml.kernel.org/r/20230413131349.2524210-1-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

...

This commit is contained in:

Liu Shixin 2023-04-13 21:13:49 +08:00 • committed by Andrew Morton

parent ec342603e6

commit 1cb9dc4b47

3 changed files with 55 additions and 27 deletions

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6

include/linux/mm.h

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17

mm/hugetlb.c

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59

mm/memory.c

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