iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mm: memory-failure: fetch compound head after extra page refcnt is held

Browse Source 
Page might become thp, huge page or being splited after compound head is
fetched but before page refcnt is bumped.  So hpage might be a tail page
leading to VM_BUG_ON_PAGE(PageTail(page)) in PageTransHuge().

Link: https://lkml.kernel.org/r/20230711055016.2286677-8-linmiaohe@huawei.com
Fixes: 415c64c1453a ("mm/memory-failure: split thp earlier in memory error handling")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Miaohe Lin 2023-07-11 13:50:15 +08:00 committed by Andrew Morton
parent 5885c6a625
commit a363d1224b
1 changed files with 1 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
mm/memory-failure.c
View File

@ -2175,8 +2175,6 @@ try_again:
goto unlock_mutex;
}
hpage = compound_head(p);
/*
* We need/can do nothing about count=0 pages.
* 1) it's a free page, and therefore in safe hand:
@ -2215,6 +2213,7 @@ try_again:
}
}
hpage = compound_head(p);
if (PageTransHuge(hpage)) {
/*
* The flag must be set after the refcount is bumped