From: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx>
commit c1f6eff304e4dfa4558b6a8c6b2d26a91db6c998 upstream.
When trying to load modules built for RISC-V which include assembly files
the kernel loader errors with "unexpected relocation type 'R_RISCV_ALIGN'"
due to R_RISCV_ALIGN relocations being generated by the assembler.
The R_RISCV_ALIGN relocations can be removed at the expense of code space
by adding -mno-relax to gcc and as. In commit 7a8e7da42250138
("RISC-V: Fixes to module loading") -mno-relax is added to the build
variable KBUILD_CFLAGS_MODULE. See [1] for more info.
The issue is that when kbuild builds a .S file, it invokes gcc with
the -mno-relax flag, but this is not being passed through to the
assembler. Adding -Wa,-mno-relax to KBUILD_AFLAGS_MODULE ensures that
the assembler is invoked correctly. This may have now been fixed in
gcc[2] and this addition should not stop newer gcc and as from working.
[1] https://github.com/riscv/riscv-elf-psabi-doc/issues/183
[2] https://github.com/gcc-mirror/gcc/commit/3b0a7d624e64eeb81e4d5e8c62c46d86ef521857
Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx>
Reviewed-by: Bin Meng <bmeng.cn@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220529152200.609809-1-ben.dooks@xxxxxxxxxxxxxxx
Fixes: ab1ef68e5401 ("RISC-V: Add sections of PLT and GOT for kernel module")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/riscv/Makefile | 1 +
1 file changed, 1 insertion(+)
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -73,6 +73,7 @@ ifeq ($(CONFIG_PERF_EVENTS),y)
endif
KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-relax)
+KBUILD_AFLAGS_MODULE += $(call as-option,-Wa$(comma)-mno-relax)
# GCC versions that support the "-mstrict-align" option default to allowing
# unaligned accesses. While unaligned accesses are explicitly allowed in the
