diff options
| author | Matthieu CASTET <castet.matthieu@free.fr> | 2011-01-20 23:11:45 +0300 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2011-02-03 03:02:36 +0300 |
| commit | f12d3d04e8f6223276abb068c5d72852174b8c31 (patch) | |
| tree | 3fa4d535cff0faad53d4b08aa252a9d522cf6ef3 | |
| parent | afe8a887550f7cc24eb16449670b93f6b43c32d8 (diff) | |
| download | linux-f12d3d04e8f6223276abb068c5d72852174b8c31.tar.xz | |
x86, nx: Don't force pages RW when setting NX bits
Xen want page table pages read only.
But the initial page table (from head_*.S) live in .data or .bss.
That was broken by 64edc8ed5ffae999d8d413ba006850e9e34166cb. There is
absolutely no reason to force these pages RW after they have already
been marked RO.
Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| -rw-r--r-- | arch/x86/mm/pageattr.c | 8 |
1 files changed, 0 insertions, 8 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 8b830ca14ac4..d343b3c81f3c 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -256,7 +256,6 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address, unsigned long pfn) { pgprot_t forbidden = __pgprot(0); - pgprot_t required = __pgprot(0); /* * The BIOS area between 640k and 1Mb needs to be executable for @@ -282,12 +281,6 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address, if (within(pfn, __pa((unsigned long)__start_rodata) >> PAGE_SHIFT, __pa((unsigned long)__end_rodata) >> PAGE_SHIFT)) pgprot_val(forbidden) |= _PAGE_RW; - /* - * .data and .bss should always be writable. - */ - if (within(address, (unsigned long)_sdata, (unsigned long)_edata) || - within(address, (unsigned long)__bss_start, (unsigned long)__bss_stop)) - pgprot_val(required) |= _PAGE_RW; #if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA) /* @@ -327,7 +320,6 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address, #endif prot = __pgprot(pgprot_val(prot) & ~pgprot_val(forbidden)); - prot = __pgprot(pgprot_val(prot) | pgprot_val(required)); return prot; } |