Messages in this thread Patch in this message | | | From | Lecopzer Chen <> | Subject | [PATCH v3 1/2] arm: kasan: support CONFIG_KASAN_VMALLOC | Date | Sun, 27 Feb 2022 21:47:25 +0800 |
| |
Simply make shadow of vmalloc area mapped on demand.
Since the virtual address of vmalloc for Arm is also between MODULE_VADDR and 0x100000000 (ZONE_HIGHMEM), which means the shadow address has already included between KASAN_SHADOW_START and KASAN_SHADOW_END. Thus we need to change nothing for memory map of Arm.
This can fix ARM_MODULE_PLTS with KASan, support KASan for higmem and provide the first step to support CONFIG_VMAP_STACK with Arm.
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com> --- arch/arm/Kconfig | 1 + arch/arm/include/asm/kasan_def.h | 11 ++++++++++- arch/arm/mm/kasan_init.c | 6 +++++- 3 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 4c97cb40eebb..78250e246cc6 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -72,6 +72,7 @@ config ARM select HAVE_ARCH_KFENCE if MMU && !XIP_KERNEL select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL + select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN select HAVE_ARCH_MMAP_RND_BITS if MMU select HAVE_ARCH_PFN_VALID select HAVE_ARCH_SECCOMP diff --git a/arch/arm/include/asm/kasan_def.h b/arch/arm/include/asm/kasan_def.h index 5739605aa7cf..96fd1d3b5a0c 100644 --- a/arch/arm/include/asm/kasan_def.h +++ b/arch/arm/include/asm/kasan_def.h @@ -19,7 +19,16 @@ * space to use as shadow memory for KASan as follows: * * +----+ 0xffffffff - * | | \ + * | |\ + * | | |-> ZONE_HIGHMEM for vmalloc virtual address space. + * | | | Such as vmalloc(), GFP_HIGHUSER (__GFP__HIGHMEM), + * | | | module address using ARM_MODULE_PLTS, etc. + * | | | + * | | | If CONFIG_KASAN_VMALLOC=y, this area would populate + * | | | shadow address on demand. + * | |/ + * +----+ VMALLOC_START + * | |\ * | | |-> Static kernel image (vmlinux) BSS and page table * | |/ * +----+ PAGE_OFFSET diff --git a/arch/arm/mm/kasan_init.c b/arch/arm/mm/kasan_init.c index 5ad0d6c56d56..29caee9c79ce 100644 --- a/arch/arm/mm/kasan_init.c +++ b/arch/arm/mm/kasan_init.c @@ -236,7 +236,11 @@ void __init kasan_init(void) clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END); - kasan_populate_early_shadow(kasan_mem_to_shadow((void *)VMALLOC_START), + if (!IS_ENABLED(CONFIG_KASAN_VMALLOC)) + kasan_populate_early_shadow(kasan_mem_to_shadow((void *)VMALLOC_START), + kasan_mem_to_shadow((void *)VMALLOC_END)); + + kasan_populate_early_shadow(kasan_mem_to_shadow((void *)VMALLOC_END), kasan_mem_to_shadow((void *)-1UL) + 1); for_each_mem_range(i, &pa_start, &pa_end) { -- 2.25.1
| |