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

From: Jan Kiszka
Date: Fri Jan 12 2024 - 13:37:49 EST


From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>

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.

Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---

Something like this should go to stable as well, but we will need
rebased patches.

drivers/firmware/efi/libstub/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 06964a3c130f..d561d7de46a9 100644
--- 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
--
2.35.3