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| author | Catalin Marinas <catalin.marinas@arm.com> | 2020-07-02 10:19:30 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-09-04 12:46:06 +0100 |
| commit | 72e6afa08e988744822f9bf18043fc04c4df2178 (patch) | |
| tree | 2a93b64e0cb4c03c82bbb896215ff51151571f39 /mm/huge_memory.c | |
| parent | 4beba9486abd2f86d125271d6946f7c38ed0fe77 (diff) | |
| download | lwn-72e6afa08e988744822f9bf18043fc04c4df2178.tar.gz lwn-72e6afa08e988744822f9bf18043fc04c4df2178.zip | |
mm: Preserve the PG_arch_2 flag in __split_huge_page_tail()
When a huge page is split into normal pages, part of the head page flags
are transferred to the tail pages. However, the PG_arch_* flags are not
part of the preserved set.
PG_arch_2 is used by the arm64 MTE support to mark pages that have valid
tags. The absence of such flag would cause the arm64 set_pte_at() to
clear the tags in order to avoid stale tags exposed to user or the
swapping out hooks to ignore the tags. Not preserving PG_arch_2 on huge
page splitting leads to tag corruption in the tail pages.
Preserve the newly added PG_arch_2 flag in __split_huge_page_tail().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 2ccff8472cd4..1a5773c95f53 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2337,6 +2337,9 @@ static void __split_huge_page_tail(struct page *head, int tail, (1L << PG_workingset) | (1L << PG_locked) | (1L << PG_unevictable) | +#ifdef CONFIG_64BIT + (1L << PG_arch_2) | +#endif (1L << PG_dirty))); /* ->mapping in first tail page is compound_mapcount */ |