[PATCH AUTOSEL 6.3 4/7] riscv: Fix EFI stub usage of KASAN instrumented strcmp function

From: Sasha Levin
Date: Mon May 08 2023 - 23:55:21 EST


From: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>

[ Upstream commit 617955ca6e275c4dd0dcf5316fca7fc04a8f2fe6 ]

The EFI stub must not use any KASAN instrumented code as the kernel
proper did not initialize the thread pointer and the mapping for the
KASAN shadow region.

Avoid using the generic strcmp function, instead use the one in
drivers/firmware/efi/libstub/string.c.

Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230203075232.274282-5-alexghiti@xxxxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/riscv/kernel/image-vars.h | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/riscv/kernel/image-vars.h b/arch/riscv/kernel/image-vars.h
index 7e2962ef73f92..15616155008cc 100644
--- a/arch/riscv/kernel/image-vars.h
+++ b/arch/riscv/kernel/image-vars.h
@@ -23,8 +23,6 @@
* linked at. The routines below are all implemented in assembler in a
* position independent manner
*/
-__efistub_strcmp = strcmp;
-
__efistub__start = _start;
__efistub__start_kernel = _start_kernel;
__efistub__end = _end;
--
2.39.2