Re: [PATCH] riscv: add correct as-options for assembly in modules

From: Ben Dooks
Date: Fri Jul 16 2021 - 06:24:40 EST


On 12/07/2021 18:48, Ben Dooks wrote:
When trying to load modules built for riscv which include assembly
the kernel loader errors with "unexpected relocation type 'R_RISCV_ALIGN'"
due to R_RISCV_ALIGN relocations being generated by the assembler.

In commit 7a8e7da42250138 ("RISC-V: Fixes to module loading")
the fix for gcc adds -mno-relax to the command line when building
C files. However this was never applied to assembly flags, and gcc
does no pass -mno-relax to gas when presented with a .S file.

The fix (other than making gcc always pass -mno-relax to gas) is
to add -Wa,-mno-relax to gcc to make sure the as is invoked with
the right options.

Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx>

Just wanted to find out if anyone has had time to review this.
If this is ok, should we also send to -stable ?

---
arch/riscv/Makefile | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 1f5c03082976..fca40511a8c6 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -60,6 +60,7 @@ 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



--
Ben Dooks http://www.codethink.co.uk/
Senior Engineer Codethink - Providing Genius

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