Commit 769a8089 authored Sep 22, 2015 by Andrey Ryabinin Committed by Linus Torvalds Sep 22, 2015

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 <ryabinin.a.a@gmail.com>
Reported-by: Fengguang Wu <fengguang.wu@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 3aaa76e1

arch/x86/include/asm/efi.h

+10 −0

Original line number	Diff line number	Diff line
		@@ -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;

drivers/firmware/efi/libstub/efistub.h

+0 −4

Original line number	Diff line number	Diff line
		@@ -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,