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author | Max Filippov <jcmvbkbc@gmail.com> | 2017-12-04 00:28:52 +0300 |
---|---|---|
committer | Max Filippov <jcmvbkbc@gmail.com> | 2017-12-17 09:37:12 +0300 |
commit | c633544a6154146a210cf158157a1ae7c55473b6 (patch) | |
tree | d670a9984373622d991c382126f341b6f32154cd /arch/xtensa/include/asm | |
parent | 1af1e8a39dc0fab5e50f10462c636da8c1e0cfbb (diff) | |
download | linux-c633544a6154146a210cf158157a1ae7c55473b6.tar.xz |
xtensa: add support for KASAN
Cover kernel addresses above 0x90000000 by the shadow map. Enable
HAVE_ARCH_KASAN when MMU is enabled. Provide kasan_early_init that fills
shadow map with writable copies of kasan_zero_page. Call
kasan_early_init right after mmu initialization in the setup_arch.
Provide kasan_init that allocates proper shadow map pages from the
memblock and puts these pages into the shadow map for addresses from
VMALLOC area to the end of KSEG. Call kasan_init right after memblock
initialization. Don't use KASAN for the boot code, MMU and KASAN
initialization and page fault handler. Make kernel stack size 4 times
larger when KASAN is enabled to avoid stack overflows.
GCC 7.3, 8 or newer is required to build the xtensa kernel with KASAN.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/include/asm')
-rw-r--r-- | arch/xtensa/include/asm/kasan.h | 37 | ||||
-rw-r--r-- | arch/xtensa/include/asm/kmem_layout.h | 4 | ||||
-rw-r--r-- | arch/xtensa/include/asm/pgtable.h | 3 | ||||
-rw-r--r-- | arch/xtensa/include/asm/string.h | 19 |
4 files changed, 62 insertions, 1 deletions
diff --git a/arch/xtensa/include/asm/kasan.h b/arch/xtensa/include/asm/kasan.h new file mode 100644 index 000000000000..54be80876e57 --- /dev/null +++ b/arch/xtensa/include/asm/kasan.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_KASAN_H +#define __ASM_KASAN_H + +#ifndef __ASSEMBLY__ + +#ifdef CONFIG_KASAN + +#include <linux/kernel.h> +#include <linux/sizes.h> +#include <asm/kmem_layout.h> + +/* Start of area covered by KASAN */ +#define KASAN_START_VADDR __XTENSA_UL_CONST(0x90000000) +/* Start of the shadow map */ +#define KASAN_SHADOW_START (XCHAL_PAGE_TABLE_VADDR + XCHAL_PAGE_TABLE_SIZE) +/* Size of the shadow map */ +#define KASAN_SHADOW_SIZE (-KASAN_START_VADDR >> KASAN_SHADOW_SCALE_SHIFT) +/* Offset for mem to shadow address transformation */ +#define KASAN_SHADOW_OFFSET __XTENSA_UL_CONST(CONFIG_KASAN_SHADOW_OFFSET) + +void __init kasan_early_init(void); +void __init kasan_init(void); + +#else + +static inline void kasan_early_init(void) +{ +} + +static inline void kasan_init(void) +{ +} + +#endif +#endif +#endif diff --git a/arch/xtensa/include/asm/kmem_layout.h b/arch/xtensa/include/asm/kmem_layout.h index 28f9260a766c..2317c835a4db 100644 --- a/arch/xtensa/include/asm/kmem_layout.h +++ b/arch/xtensa/include/asm/kmem_layout.h @@ -71,7 +71,11 @@ #endif +#ifndef CONFIG_KASAN #define KERNEL_STACK_SHIFT 13 +#else +#define KERNEL_STACK_SHIFT 15 +#endif #define KERNEL_STACK_SIZE (1 << KERNEL_STACK_SHIFT) #endif diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h index 30dd5b2e4ad5..38802259978f 100644 --- a/arch/xtensa/include/asm/pgtable.h +++ b/arch/xtensa/include/asm/pgtable.h @@ -12,9 +12,9 @@ #define _XTENSA_PGTABLE_H #define __ARCH_USE_5LEVEL_HACK -#include <asm-generic/pgtable-nopmd.h> #include <asm/page.h> #include <asm/kmem_layout.h> +#include <asm-generic/pgtable-nopmd.h> /* * We only use two ring levels, user and kernel space. @@ -170,6 +170,7 @@ #define PAGE_SHARED_EXEC \ __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITABLE | _PAGE_HW_EXEC) #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_HW_WRITE) +#define PAGE_KERNEL_RO __pgprot(_PAGE_PRESENT) #define PAGE_KERNEL_EXEC __pgprot(_PAGE_PRESENT|_PAGE_HW_WRITE|_PAGE_HW_EXEC) #if (DCACHE_WAY_SIZE > PAGE_SIZE) diff --git a/arch/xtensa/include/asm/string.h b/arch/xtensa/include/asm/string.h index 8d5d9dfadb09..586bad9fe187 100644 --- a/arch/xtensa/include/asm/string.h +++ b/arch/xtensa/include/asm/string.h @@ -108,14 +108,33 @@ static inline int strncmp(const char *__cs, const char *__ct, size_t __n) #define __HAVE_ARCH_MEMSET extern void *memset(void *__s, int __c, size_t __count); +extern void *__memset(void *__s, int __c, size_t __count); #define __HAVE_ARCH_MEMCPY extern void *memcpy(void *__to, __const__ void *__from, size_t __n); +extern void *__memcpy(void *__to, __const__ void *__from, size_t __n); #define __HAVE_ARCH_MEMMOVE extern void *memmove(void *__dest, __const__ void *__src, size_t __n); +extern void *__memmove(void *__dest, __const__ void *__src, size_t __n); /* Don't build bcopy at all ... */ #define __HAVE_ARCH_BCOPY +#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__) + +/* + * For files that are not instrumented (e.g. mm/slub.c) we + * should use not instrumented version of mem* functions. + */ + +#define memcpy(dst, src, len) __memcpy(dst, src, len) +#define memmove(dst, src, len) __memmove(dst, src, len) +#define memset(s, c, n) __memset(s, c, n) + +#ifndef __NO_FORTIFY +#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */ +#endif +#endif + #endif /* _XTENSA_STRING_H */ |