Thread (43 messages) 43 messages, 3 authors, 2021-04-26

Re: [PATCH v25 20/30] mm/mprotect: Exclude shadow stack from preserve_write

From: Kirill A. Shutemov <hidden>
Date: 2021-04-23 10:27:14
Also in: linux-arch, linux-doc, linux-mm, lkml

On Thu, Apr 15, 2021 at 03:14:09PM -0700, Yu-cheng Yu wrote:
In change_pte_range(), when a PTE is changed for prot_numa, _PAGE_RW is
preserved to avoid the additional write fault after the NUMA hinting fault.
However, pte_write() now includes both normal writable and shadow stack
(RW=0, Dirty=1) PTEs, but the latter does not have _PAGE_RW and has no need
to preserve it.

Exclude shadow stack from preserve_write test, and apply the same change to
change_huge_pmd().

Signed-off-by: Yu-cheng Yu <redacted>
Reviewed-by: Kirill A. Shutemov <redacted>

-- 
 Kirill A. Shutemov
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