diff options
| author | Andrey Ryabinin <a.ryabinin@samsung.com> | 2015-02-13 14:39:25 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-13 21:21:41 -0800 |
| commit | ef7f0d6a6ca8c9e4b27d78895af86c2fbfaeedb2 (patch) | |
| tree | ac747fe9eb870b1c501f0f13063b092bd1ff0e97 /arch/x86/kernel/head_64.S | |
| parent | 786a8959912eb94fc2381c2ae487a96ce55dabca (diff) | |
x86_64: add KASan support
This patch adds arch specific code for kernel address sanitizer.
16TB of virtual addressed used for shadow memory. It's located in range
[ffffec0000000000 - fffffc0000000000] between vmemmap and %esp fixup
stacks.
At early stage we map whole shadow region with zero page. Latter, after
pages mapped to direct mapping address range we unmap zero pages from
corresponding shadow (see kasan_map_shadow()) and allocate and map a real
shadow memory reusing vmemmap_populate() function.
Also replace __pa with __pa_nodebug before shadow initialized. __pa with
CONFIG_DEBUG_VIRTUAL=y make external function call (__phys_addr)
__phys_addr is instrumented, so __asan_load could be called before shadow
area initialized.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel/head_64.S')
| -rw-r--r-- | arch/x86/kernel/head_64.S | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index a468c0a65c42..6fd514d9f69a 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -514,8 +514,38 @@ ENTRY(phys_base) /* This must match the first entry in level2_kernel_pgt */ .quad 0x0000000000000000 +#ifdef CONFIG_KASAN +#define FILL(VAL, COUNT) \ + .rept (COUNT) ; \ + .quad (VAL) ; \ + .endr + +NEXT_PAGE(kasan_zero_pte) + FILL(kasan_zero_page - __START_KERNEL_map + _KERNPG_TABLE, 512) +NEXT_PAGE(kasan_zero_pmd) + FILL(kasan_zero_pte - __START_KERNEL_map + _KERNPG_TABLE, 512) +NEXT_PAGE(kasan_zero_pud) + FILL(kasan_zero_pmd - __START_KERNEL_map + _KERNPG_TABLE, 512) + +#undef FILL +#endif + + #include "../../x86/xen/xen-head.S" __PAGE_ALIGNED_BSS NEXT_PAGE(empty_zero_page) .skip PAGE_SIZE + +#ifdef CONFIG_KASAN +/* + * This page used as early shadow. We don't use empty_zero_page + * at early stages, stack instrumentation could write some garbage + * to this page. + * Latter we reuse it as zero shadow for large ranges of memory + * that allowed to access, but not instrumented by kasan + * (vmalloc/vmemmap ...). + */ +NEXT_PAGE(kasan_zero_page) + .skip PAGE_SIZE +#endif |