The patch titled
x86_64: NX bit handling in change_page_attr
has been added to the -mm tree. Its filename is
x86_64-nx-bit-handling-in-change_page_attr.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: x86_64: NX bit handling in change_page_attr
From: "Huang, Ying" <ying.huang@xxxxxxxxx>
This patch fixes a bug of change_page_attr/change_page_attr_addr on Intel
x86_64 CPU. After changing page attribute to be executable with these
functions, the page remains un-executable on Intel x86_64 CPU. Because on
Intel x86_64 CPU, only if the "NX" bits of all four level page tables are
cleared, the corresponding page is executable (refer to section 4.13.2 of
Intel 64 and IA-32 Architectures Software Developer's Manual). So, the bug
is fixed through clearing the "NX" bit of PMD when splitting the huge PMD.
Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86_64/mm/pageattr.c | 1 +
1 file changed, 1 insertion(+)
diff -puN arch/x86_64/mm/pageattr.c~x86_64-nx-bit-handling-in-change_page_attr arch/x86_64/mm/pageattr.c
--- a/arch/x86_64/mm/pageattr.c~x86_64-nx-bit-handling-in-change_page_attr
+++ a/arch/x86_64/mm/pageattr.c
@@ -189,6 +189,7 @@ __change_page_attr(unsigned long address
split = split_large_page(address, prot, ref_prot2);
if (!split)
return -ENOMEM;
+ pgprot_val(ref_prot2) &= ~_PAGE_NX;
set_pte(kpte, mk_pte(split, ref_prot2));
kpte_page = split;
}
_
Patches currently in -mm which might be from ying.huang@xxxxxxxxx are
x86_64-nx-bit-handling-in-change_page_attr.patch
x86_64-efi-boot-support-efi-frame-buffer-driver.patch
x86_64-efi-boot-support-efi-boot-document.patch
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