diff options
| author | Yinghai Lu <yinghai@kernel.org> | 2013-01-24 12:20:13 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2013-01-29 19:32:58 -0800 |
| commit | 72212675d1c96f5db8ec6fb35701879911193158 (patch) | |
| tree | 179134ac8592f6341af2f847ace7eba4d5bebb31 /arch | |
| parent | 6c902b656c4a808d9c6f40a387b166455efecd62 (diff) | |
x86, 64bit, mm: Mark data/bss/brk to nx
HPA said, we should not have RW and +x set at the time.
for kernel layout:
[ 0.000000] Kernel Layout:
[ 0.000000] .text: [0x01000000-0x021434f8]
[ 0.000000] .rodata: [0x02200000-0x02a13fff]
[ 0.000000] .data: [0x02c00000-0x02dc763f]
[ 0.000000] .init: [0x02dc9000-0x0312cfff]
[ 0.000000] .bss: [0x0313b000-0x03dd6fff]
[ 0.000000] .brk: [0x03dd7000-0x03dfffff]
before the patch, we have
---[ High Kernel Mapping ]---
0xffffffff80000000-0xffffffff81000000 16M pmd
0xffffffff81000000-0xffffffff82200000 18M ro PSE GLB x pmd
0xffffffff82200000-0xffffffff82c00000 10M ro PSE GLB NX pmd
0xffffffff82c00000-0xffffffff82dc9000 1828K RW GLB x pte
0xffffffff82dc9000-0xffffffff82e00000 220K RW GLB NX pte
0xffffffff82e00000-0xffffffff83000000 2M RW PSE GLB NX pmd
0xffffffff83000000-0xffffffff8313a000 1256K RW GLB NX pte
0xffffffff8313a000-0xffffffff83200000 792K RW GLB x pte
0xffffffff83200000-0xffffffff83e00000 12M RW PSE GLB x pmd
0xffffffff83e00000-0xffffffffa0000000 450M pmd
after patch,, we get
---[ High Kernel Mapping ]---
0xffffffff80000000-0xffffffff81000000 16M pmd
0xffffffff81000000-0xffffffff82200000 18M ro PSE GLB x pmd
0xffffffff82200000-0xffffffff82c00000 10M ro PSE GLB NX pmd
0xffffffff82c00000-0xffffffff82e00000 2M RW GLB NX pte
0xffffffff82e00000-0xffffffff83000000 2M RW PSE GLB NX pmd
0xffffffff83000000-0xffffffff83200000 2M RW GLB NX pte
0xffffffff83200000-0xffffffff83e00000 12M RW PSE GLB NX pmd
0xffffffff83e00000-0xffffffffa0000000 450M pmd
so data, bss, brk get NX ...
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-33-git-send-email-yinghai@kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/mm/init_64.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index dc67337d9bf..e2fcbc34c9d 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -810,6 +810,7 @@ void mark_rodata_ro(void) unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table); unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata); unsigned long data_start = (unsigned long) &_sdata; + unsigned long all_end = PFN_ALIGN(&_end); printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", (end - start) >> 10); @@ -818,10 +819,10 @@ void mark_rodata_ro(void) kernel_set_to_readonly = 1; /* - * The rodata section (but not the kernel text!) should also be - * not-executable. + * The rodata/data/bss/brk section (but not the kernel text!) + * should also be not-executable. */ - set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT); + set_memory_nx(rodata_start, (all_end - rodata_start) >> PAGE_SHIFT); rodata_test(); |