From c633544a6154146a210cf158157a1ae7c55473b6 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Sun, 3 Dec 2017 13:28:52 -0800 Subject: 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 --- arch/xtensa/include/asm/pgtable.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/xtensa/include/asm/pgtable.h') 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 #include #include +#include /* * 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) -- cgit v1.2.3