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authorYinghai Lu <yinghai@kernel.org>2013-01-24 12:20:13 -0800
committerH. Peter Anvin <hpa@linux.intel.com>2013-01-29 19:32:58 -0800
commit72212675d1c96f5db8ec6fb35701879911193158 (patch)
tree179134ac8592f6341af2f847ace7eba4d5bebb31
parent6c902b656c4a808d9c6f40a387b166455efecd62 (diff)
downloadop-kernel-dev-72212675d1c96f5db8ec6fb35701879911193158.zip
op-kernel-dev-72212675d1c96f5db8ec6fb35701879911193158.tar.gz
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>
-rw-r--r--arch/x86/mm/init_64.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index dc67337..e2fcbc3 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();
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