riscv/efistub: Ensure GP-relative addressing is not used

The cflags for the RISC-V efistub were missing -mno-relax, thus were
under the risk that the compiler could use GP-relative addressing. That
happened for _edata with binutils-2.41 and kernel 6.1, causing the
relocation to fail due to an invalid kernel_size in handle_kernel_image.
It was not yet observed with newer versions, but that may just be luck.

Cc: <stable@vger.kernel.org>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 06964a3c130f6addeed20eca1ed26153a2260854..d561d7de46a99731ac0aef536426b6bc3f2a1241 100644 (file)
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -28,7 +28,7 @@ cflags-$(CONFIG_ARM)          += -DEFI_HAVE_STRLEN -DEFI_HAVE_STRNLEN \
                                   -DEFI_HAVE_MEMCHR -DEFI_HAVE_STRRCHR \
                                   -DEFI_HAVE_STRCMP -fno-builtin -fpic \
                                   $(call cc-option,-mno-single-pic-base)
-cflags-$(CONFIG_RISCV)         += -fpic -DNO_ALTERNATIVE
+cflags-$(CONFIG_RISCV)         += -fpic -DNO_ALTERNATIVE -mno-relax
 cflags-$(CONFIG_LOONGARCH)     += -fpie
 
 cflags-$(CONFIG_EFI_PARAMS_FROM_FDT)   += -I$(srctree)/scripts/dtc/libfdt