riscv: Pass -mno-relax only on lld < 15.0.0

lld since llvm:6611d58f5bbc ("[ELF] Relax R_RISCV_ALIGN"), which will be
included in the 15.0.0 release, has implemented some RISC-V linker
relaxation.  -mno-relax is no longer needed in
KBUILD_CFLAGS/KBUILD_AFLAGS to suppress R_RISCV_ALIGN which older lld
can not handle:

    ld.lld: error: capability.c:(.fixup+0x0): relocation R_RISCV_ALIGN
    requires unimplemented linker relaxation; recompile with -mno-relax
    but the .o is already compiled with -mno-relax

Signed-off-by: Fangrui Song <[email protected]>
Link: https://lore.kernel.org/r/[email protected]/
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Nick Desaulniers <[email protected]>
Tested-by: Nick Desaulniers <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
Tested-by: Conor Dooley <[email protected]>
Cc: [email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index d63295e213731b46040fcf4251acc1b889e4a7c9..76364cf67a72e8a619990011765591b2369cc895 100644 (file)
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -37,6 +37,7 @@ else
 endif
 
 ifeq ($(CONFIG_LD_IS_LLD),y)
+ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 150000; echo $$?),0)
        KBUILD_CFLAGS += -mno-relax
        KBUILD_AFLAGS += -mno-relax
 ifndef CONFIG_AS_IS_LLVM
@@ -44,6 +45,7 @@ ifndef CONFIG_AS_IS_LLVM
        KBUILD_AFLAGS += -Wa,-mno-relax
 endif
 endif
+endif
 
 # ISA string setting
 riscv-march-$(CONFIG_ARCH_RV32I)       := rv32ima