diff options
author | Alexander Potapenko <glider@google.com> | 2022-08-26 17:08:07 +0200 |
---|---|---|
committer | Marco Elver <elver@google.com> | 2022-08-29 14:15:37 +0200 |
commit | e2e8931f869bff47f4bbe30a76e79e5fe0f93f94 (patch) | |
tree | e4729cd426923449dcee255484592b8c4df0c6ae | |
parent | 40eb36f05196243e85cbb171872f0cb6d97f047f (diff) | |
download | linux-review/kmsan.tar.gz |
x86: kmsan: enable KMSAN builds for x86review/kmsan
Make KMSAN usable by adding the necessary Kconfig bits.
Also declare x86-specific functions checking address validity
in arch/x86/include/asm/kmsan.h.
Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Marco Elver <elver@google.com>
-rw-r--r-- | arch/x86/Kconfig | 1 | ||||
-rw-r--r-- | arch/x86/include/asm/kmsan.h | 55 |
2 files changed, 56 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 697da8dae1418c..bd9436cd0f29bb 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -168,6 +168,7 @@ config X86 select HAVE_ARCH_KASAN if X86_64 select HAVE_ARCH_KASAN_VMALLOC if X86_64 select HAVE_ARCH_KFENCE + select HAVE_ARCH_KMSAN if X86_64 select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS if MMU select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT diff --git a/arch/x86/include/asm/kmsan.h b/arch/x86/include/asm/kmsan.h new file mode 100644 index 00000000000000..a790b865d0a68c --- /dev/null +++ b/arch/x86/include/asm/kmsan.h @@ -0,0 +1,55 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * x86 KMSAN support. + * + * Copyright (C) 2022, Google LLC + * Author: Alexander Potapenko <glider@google.com> + */ + +#ifndef _ASM_X86_KMSAN_H +#define _ASM_X86_KMSAN_H + +#ifndef MODULE + +#include <asm/processor.h> +#include <linux/mmzone.h> + +/* + * Taken from arch/x86/mm/physaddr.h to avoid using an instrumented version. + */ +static inline bool kmsan_phys_addr_valid(unsigned long addr) +{ + if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT)) + return !(addr >> boot_cpu_data.x86_phys_bits); + else + return true; +} + +/* + * Taken from arch/x86/mm/physaddr.c to avoid using an instrumented version. + */ +static inline bool kmsan_virt_addr_valid(void *addr) +{ + unsigned long x = (unsigned long)addr; + unsigned long y = x - __START_KERNEL_map; + + /* use the carry flag to determine if x was < __START_KERNEL_map */ + if (unlikely(x > y)) { + x = y + phys_base; + + if (y >= KERNEL_IMAGE_SIZE) + return false; + } else { + x = y + (__START_KERNEL_map - PAGE_OFFSET); + + /* carry flag will be set if starting x was >= PAGE_OFFSET */ + if ((x > y) || !kmsan_phys_addr_valid(x)) + return false; + } + + return pfn_valid(x >> PAGE_SHIFT); +} + +#endif /* !MODULE */ + +#endif /* _ASM_X86_KMSAN_H */ |