In not-instrumented code KASAN replaces instrumented memset/memcpy/memmove with not-instrumented analogues __memset/__memcpy/__memove. However, on x86 the EFI stub is not linked with the kernel. It uses not-instrumented mem*() functions from arch/x86/boot/compressed/string.c So we don't replace them with __mem*() variants in EFI stub.
On ARM64 the EFI stub is linked with the kernel, so we should replace mem*() functions with __mem*(), because the EFI stub runs before KASAN sets up early shadow. So let's move these #undef mem* into arch's asm/efi.h which is also included by the EFI stub. Also, this will fix the warning in 32-bit build reported by kbuild test robot <[email protected]>: efi-stub-helper.c:599:2: warning: implicit declaration of function 'memcpy' Signed-off-by: Andrey Ryabinin <[email protected]> --- arch/x86/include/asm/efi.h | 12 ++++++++++++ drivers/firmware/efi/libstub/efistub.h | 4 ---- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 155162e..6db2742 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -86,6 +86,18 @@ extern u64 asmlinkage efi_call(void *fp, ...); extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size, u32 type, u64 attribute); +/* + * CONFIG_KASAN may redefine memset to __memset. + * __memset function is present only in kernel binary. + * Since the EFI stub linked into a separate binary it + * doesn't have __memset(). So we should use standard + * memset from arch/x86/boot/compressed/string.c + * The same applies to memcpy and memmove. + */ +#undef memcpy +#undef memset +#undef memmove + #endif /* CONFIG_X86_32 */ extern struct efi_scratch efi_scratch; diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index e334a01..6b6548f 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -5,10 +5,6 @@ /* error code which can't be mistaken for valid address */ #define EFI_ERROR (~0UL) -#undef memcpy -#undef memset -#undef memmove - void efi_char16_printk(efi_system_table_t *, efi_char16_t *); efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg, void *__image, -- 2.4.6 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
