diff options
| -rw-r--r-- | arch/arm64/include/asm/asm-prototypes.h | 6 | ||||
| -rw-r--r-- | arch/arm64/include/asm/module.lds.h | 17 | ||||
| -rw-r--r-- | arch/arm64/lib/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm64/lib/kasan_sw_tags.S | 76 | ||||
| -rw-r--r-- | mm/kasan/sw_tags.c | 7 | ||||
| -rw-r--r-- | scripts/Makefile.kasan | 1 |
6 files changed, 107 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/asm-prototypes.h b/arch/arm64/include/asm/asm-prototypes.h index 1c9a3a0c5fa5..ec1d9655f885 100644 --- a/arch/arm64/include/asm/asm-prototypes.h +++ b/arch/arm64/include/asm/asm-prototypes.h @@ -23,4 +23,10 @@ long long __ashlti3(long long a, int b); long long __ashrti3(long long a, int b); long long __lshrti3(long long a, int b); +/* + * This function uses a custom calling convention and cannot be called from C so + * this prototype is not entirely accurate. + */ +void __hwasan_tag_mismatch(unsigned long addr, unsigned long access_info); + #endif /* __ASM_PROTOTYPES_H */ diff --git a/arch/arm64/include/asm/module.lds.h b/arch/arm64/include/asm/module.lds.h index 810045628c66..a11ccadd47d2 100644 --- a/arch/arm64/include/asm/module.lds.h +++ b/arch/arm64/include/asm/module.lds.h @@ -1,7 +1,20 @@ -#ifdef CONFIG_ARM64_MODULE_PLTS SECTIONS { +#ifdef CONFIG_ARM64_MODULE_PLTS .plt 0 (NOLOAD) : { BYTE(0) } .init.plt 0 (NOLOAD) : { BYTE(0) } .text.ftrace_trampoline 0 (NOLOAD) : { BYTE(0) } -} #endif + +#ifdef CONFIG_KASAN_SW_TAGS + /* + * Outlined checks go into comdat-deduplicated sections named .text.hot. + * Because they are in comdats they are not combined by the linker and + * we otherwise end up with multiple sections with the same .text.hot + * name in the .ko file. The kernel module loader warns if it sees + * multiple sections with the same name so we use this sections + * directive to force them into a single section and silence the + * warning. + */ + .text.hot : { *(.text.hot) } +#endif +} diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile index d31e1169d9b8..8e60d76a1b47 100644 --- a/arch/arm64/lib/Makefile +++ b/arch/arm64/lib/Makefile @@ -18,3 +18,5 @@ obj-$(CONFIG_CRC32) += crc32.o obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o obj-$(CONFIG_ARM64_MTE) += mte.o + +obj-$(CONFIG_KASAN_SW_TAGS) += kasan_sw_tags.o diff --git a/arch/arm64/lib/kasan_sw_tags.S b/arch/arm64/lib/kasan_sw_tags.S new file mode 100644 index 000000000000..5b04464c045e --- /dev/null +++ b/arch/arm64/lib/kasan_sw_tags.S @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 Google LLC + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> + +/* + * Report a tag mismatch detected by tag-based KASAN. + * + * A compiler-generated thunk calls this with a non-AAPCS calling + * convention. Upon entry to this function, registers are as follows: + * + * x0: fault address (see below for restore) + * x1: fault description (see below for restore) + * x2 to x15: callee-saved + * x16 to x17: safe to clobber + * x18 to x30: callee-saved + * sp: pre-decremented by 256 bytes (see below for restore) + * + * The caller has decremented the SP by 256 bytes, and created a + * structure on the stack as follows: + * + * sp + 0..15: x0 and x1 to be restored + * sp + 16..231: free for use + * sp + 232..247: x29 and x30 (same as in GPRs) + * sp + 248..255: free for use + * + * Note that this is not a struct pt_regs. + * + * To call a regular AAPCS function we must save x2 to x15 (which we can + * store in the gaps), and create a frame record (for which we can use + * x29 and x30 spilled by the caller as those match the GPRs). + * + * The caller expects x0 and x1 to be restored from the structure, and + * for the structure to be removed from the stack (i.e. the SP must be + * incremented by 256 prior to return). + */ +SYM_CODE_START(__hwasan_tag_mismatch) +#ifdef BTI_C + BTI_C +#endif + add x29, sp, #232 + stp x2, x3, [sp, #8 * 2] + stp x4, x5, [sp, #8 * 4] + stp x6, x7, [sp, #8 * 6] + stp x8, x9, [sp, #8 * 8] + stp x10, x11, [sp, #8 * 10] + stp x12, x13, [sp, #8 * 12] + stp x14, x15, [sp, #8 * 14] +#ifndef CONFIG_SHADOW_CALL_STACK + str x18, [sp, #8 * 18] +#endif + + mov x2, x30 + bl kasan_tag_mismatch + + ldp x0, x1, [sp] + ldp x2, x3, [sp, #8 * 2] + ldp x4, x5, [sp, #8 * 4] + ldp x6, x7, [sp, #8 * 6] + ldp x8, x9, [sp, #8 * 8] + ldp x10, x11, [sp, #8 * 10] + ldp x12, x13, [sp, #8 * 12] + ldp x14, x15, [sp, #8 * 14] +#ifndef CONFIG_SHADOW_CALL_STACK + ldr x18, [sp, #8 * 18] +#endif + ldp x29, x30, [sp, #8 * 29] + + /* remove the structure from the stack */ + add sp, sp, #256 + ret +SYM_CODE_END(__hwasan_tag_mismatch) +EXPORT_SYMBOL(__hwasan_tag_mismatch) diff --git a/mm/kasan/sw_tags.c b/mm/kasan/sw_tags.c index 9df8e7f69e87..9362938abbfa 100644 --- a/mm/kasan/sw_tags.c +++ b/mm/kasan/sw_tags.c @@ -207,3 +207,10 @@ struct kasan_track *kasan_get_free_track(struct kmem_cache *cache, return &alloc_meta->free_track[i]; } + +void kasan_tag_mismatch(unsigned long addr, unsigned long access_info, + unsigned long ret_ip) +{ + kasan_report(addr, 1 << (access_info & 0xf), access_info & 0x10, + ret_ip); +} diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan index 3d791908ed36..801c415bac59 100644 --- a/scripts/Makefile.kasan +++ b/scripts/Makefile.kasan @@ -50,6 +50,7 @@ endif CFLAGS_KASAN := -fsanitize=kernel-hwaddress \ $(call cc-param,hwasan-instrument-stack=$(stack_enable)) \ $(call cc-param,hwasan-use-short-granules=0) \ + $(call cc-param,hwasan-inline-all-checks=0) \ $(instrumentation_flags) endif # CONFIG_KASAN_SW_TAGS |