From 5aa4ac64e6add3e40d5049e31275b2822daf885d Mon Sep 17 00:00:00 2001 From: Qing Zhang Date: Wed, 6 Sep 2023 22:54:16 +0800 Subject: LoongArch: Add KASAN (Kernel Address Sanitizer) support 1/8 of kernel addresses reserved for shadow memory. But for LoongArch, There are a lot of holes between different segments and valid address space (256T available) is insufficient to map all these segments to kasan shadow memory with the common formula provided by kasan core, saying (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET So LoongArch has a arch-specific mapping formula, different segments are mapped individually, and only limited space lengths of these specific segments are mapped to shadow. At early boot stage the whole shadow region populated with just one physical page (kasan_early_shadow_page). Later, this page is reused as readonly zero shadow for some memory that kasan currently don't track. After mapping the physical memory, pages for shadow memory are allocated and mapped. Functions like memset()/memcpy()/memmove() do a lot of memory accesses. If bad pointer passed to one of these function it is important to be caught. Compiler's instrumentation cannot do this since these functions are written in assembly. KASan replaces memory functions with manually instrumented variants. Original functions declared as weak symbols so strong definitions in mm/kasan/kasan.c could replace them. Original functions have aliases with '__' prefix in names, so we could call non-instrumented variant if needed. Signed-off-by: Qing Zhang Signed-off-by: Huacai Chen --- Documentation/translations/zh_CN/dev-tools/kasan.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation/translations/zh_CN') diff --git a/Documentation/translations/zh_CN/dev-tools/kasan.rst b/Documentation/translations/zh_CN/dev-tools/kasan.rst index 05ef904dbcfb..8fdb20c9665b 100644 --- a/Documentation/translations/zh_CN/dev-tools/kasan.rst +++ b/Documentation/translations/zh_CN/dev-tools/kasan.rst @@ -42,7 +42,7 @@ KASAN有三种模式: 体系架构 ~~~~~~~~ -在x86_64、arm、arm64、powerpc、riscv、s390和xtensa上支持通用KASAN， +在x86_64、arm、arm64、powerpc、riscv、s390、xtensa和loongarch上支持通用KASAN， 而基于标签的KASAN模式只在arm64上支持。 编译器 -- cgit v1.2.3