[PATCH 2/2] MIPS: VDSO: Do not disable VDSO when linking with ld.lld

Nathan Chancellor
2020-04-19T18:05:06Z

Currently, when linking with ld.lld, this warning pops up:

arch/mips/vdso/Makefile:70: MIPS VDSO requires binutils >= 2.25

ld-ifversion calls ld-version, which calls scripts/ld-version.sh, which
is specific to GNU ld. ld.lld has a completely different versioning
scheme (as it follows LLVM's versioning) and it does not have the issue
mentioned in the comment above this block so it should not be subjected
to this check.

With this patch, the VDSO successfully links and shows P_MIPS_PC32 in
vgettimeofday.o.

$ llvm-objdump -Dr arch/mips/vdso/vgettimeofday.o | grep R_MIPS_PC32
00000024: R_MIPS_PC32 _start
000000b0: R_MIPS_PC32 _start
000002bc: R_MIPS_PC32 _start
0000036c: R_MIPS_PC32 _start
00000468: R_MIPS_PC32 _start

Link: https://github.com/ClangBuiltLinux/linux/issues/785
Link: https://github.com/llvm/llvm-project/commit/e364e2e9ce50c12eb2bf093560e1a1a8544d455a
Reported-by: Dmitry Golovin <dima@golovin.in>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
arch/mips/vdso/Makefile | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile
index d7fe8408603e..f99e583d14a1 100644
--- a/arch/mips/vdso/Makefile
+++ b/arch/mips/vdso/Makefile
@@ -65,9 +65,11 @@ DISABLE_VDSO := n
# the comments on that file.
#
ifndef CONFIG_CPU_MIPSR6
- ifeq ($(call ld-ifversion, -lt, 225000000, y),y)
- $(warning MIPS VDSO requires binutils >= 2.25)
- DISABLE_VDSO := y
+ ifndef CONFIG_LD_IS_LLD
+ ifeq ($(call ld-ifversion, -lt, 225000000, y),y)
+ $(warning MIPS VDSO requires binutils >= 2.25)
+ DISABLE_VDSO := y
+ endif
endif
endif

--
2.26.1