From 769a8089c1fd2fe94c13e66fe6e03d7820953ee3 Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Tue, 22 Sep 2015 14:59:17 -0700 Subject: [PATCH] x86, efi, kasan: #undef memset/memcpy/memmove per arch 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: efi-stub-helper.c:599:2: warning: implicit declaration of function 'memcpy' [akpm@linux-foundation.org: use 80 cols in comment] Signed-off-by: Andrey Ryabinin Reported-by: Fengguang Wu Cc: Will Deacon Cc: Catalin Marinas Cc: Matt Fleming Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/include/asm/efi.h | 10 ++++++++++ drivers/firmware/efi/libstub/efistub.h | 4 ---- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 155162ea0e00..ab5f1d447ef9 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -86,6 +86,16 @@ 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 e334a01cf92f..6b6548fda089 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, -- 2.30.2