The patch titled
x86: fix mprotect's NX handling on PAE
has been added to the -mm tree. Its filename is
x86-fix-mprotects-nx-handling-on-pae.patch
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------------------------------------------------------
Subject: x86: fix mprotect's NX handling on PAE
From: Hugh Dickins <hugh@xxxxxxxxxxx>
2.6.26-rc3 with CONFIG_X86_PAE may leave the NX bit set when PROT_EXEC
is intending to clear it, causing irqbalance and others to segfault,
and X startup to fail.
This comes from an assumption in
1c12c4cf9411eb130b245fa8d0fbbaf989477c7b mprotect: prevent alteration
of the PAT bits, that PTE_MASK is what it's supposed to be: whereas
it's been wrong forever with PAE, staying 32-bit where 64-bit is
needed.
Jeremy Fitzhardinge already has patches to fix that in Ingo's tree; but
if they're not considered 2.6.26 material, or people want a quick
two-liner to get working, here's a shorter hack to fix up pte_modify.
I apologize to those we've broken, and to Venki Pallipadi: it was I who
persuaded him to change his working patch to make that false
assumption.
Signed-off-by: Hugh Dickins <hugh@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/asm-x86/pgtable.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff -puN include/asm-x86/pgtable.h~x86-fix-mprotects-nx-handling-on-pae include/asm-x86/pgtable.h
--- a/include/asm-x86/pgtable.h~x86-fix-mprotects-nx-handling-on-pae
+++ a/include/asm-x86/pgtable.h
@@ -57,8 +57,8 @@
#define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | \
_PAGE_DIRTY)
-#define _PAGE_CHG_MASK (PTE_MASK | _PAGE_PCD | _PAGE_PWT | \
- _PAGE_ACCESSED | _PAGE_DIRTY)
+#define _PAGE_CHG_MASK (((pteval_t) PTE_MASK & ~_PAGE_NX) | \
+ _PAGE_PCD | _PAGE_PWT | _PAGE_ACCESSED | _PAGE_DIRTY)
#define _PAGE_CACHE_MASK (_PAGE_PCD | _PAGE_PWT)
#define _PAGE_CACHE_WB (0)
_
Patches currently in -mm which might be from hugh@xxxxxxxxxxx are
git-unionfs.patch
x86-fix-mprotects-nx-handling-on-pae.patch
access_process_vm-device-memory-infrastructure.patch
use-generic_access_phys-for-dev-mem-mappings.patch
use-generic_access_phys-for-pci-mmap-on-x86.patch
powerpc-ioremap_prot.patch
spufs-use-the-new-vm_ops-access.patch
spufs-use-the-new-vm_ops-access-fix.patch
mm-remove-double-indirection-on-tlb-parameter-to-free_pgd_range-co.patch
memcg-better-migration-handling.patch
memcg-remove-refcnt-from-page_cgroup.patch
memcg-handle-swap-cache.patch
memcg-helper-function-for-relcaim-from-shmem.patch
memcg-add-hints-for-branch.patch
memcg-remove-a-redundant-check.patch
prio_tree-debugging-patch.patch
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