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| author | Max Filippov <jcmvbkbc@gmail.com> | 2017-12-03 13:28:52 -0800 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2017-12-16 22:37:12 -0800 |
| commit | c633544a6154146a210cf158157a1ae7c55473b6 (patch) | |
| tree | d670a9984373622d991c382126f341b6f32154cd /Documentation/xtensa | |
| parent | 1af1e8a39dc0fab5e50f10462c636da8c1e0cfbb (diff) | |
| download | lwn-c633544a6154146a210cf158157a1ae7c55473b6.tar.gz lwn-c633544a6154146a210cf158157a1ae7c55473b6.zip | |
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 'Documentation/xtensa')
| -rw-r--r-- | Documentation/xtensa/mmu.txt | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/xtensa/mmu.txt b/Documentation/xtensa/mmu.txt index 16921393e366..318114de63f3 100644 --- a/Documentation/xtensa/mmu.txt +++ b/Documentation/xtensa/mmu.txt @@ -71,6 +71,8 @@ Default MMUv2-compatible layout. +------------------+ | Page table | XCHAL_PAGE_TABLE_VADDR 0x80000000 XCHAL_PAGE_TABLE_SIZE +------------------+ +| KASAN shadow map | KASAN_SHADOW_START 0x80400000 KASAN_SHADOW_SIZE ++------------------+ 0x8e400000 +------------------+ | VMALLOC area | VMALLOC_START 0xc0000000 128MB - 64KB +------------------+ VMALLOC_END @@ -111,6 +113,8 @@ Default MMUv2-compatible layout. +------------------+ | Page table | XCHAL_PAGE_TABLE_VADDR 0x80000000 XCHAL_PAGE_TABLE_SIZE +------------------+ +| KASAN shadow map | KASAN_SHADOW_START 0x80400000 KASAN_SHADOW_SIZE ++------------------+ 0x8e400000 +------------------+ | VMALLOC area | VMALLOC_START 0xa0000000 128MB - 64KB +------------------+ VMALLOC_END @@ -152,6 +156,8 @@ Default MMUv2-compatible layout. +------------------+ | Page table | XCHAL_PAGE_TABLE_VADDR 0x80000000 XCHAL_PAGE_TABLE_SIZE +------------------+ +| KASAN shadow map | KASAN_SHADOW_START 0x80400000 KASAN_SHADOW_SIZE ++------------------+ 0x8e400000 +------------------+ | VMALLOC area | VMALLOC_START 0x90000000 128MB - 64KB +------------------+ VMALLOC_END |