Commit ccbef1674a ("Kbuild, lto: add ld-version and ld-ifversion
macros") introduced scripts/ld-version.sh for GCC LTO.
At that time, this script handled 5 version fields because GCC LTO
needed the downstream binutils. (https://lkml.org/lkml/2014/4/8/272)
The code snippet from the submitted patch was as follows:
# We need HJ Lu's Linux binutils because mainline binutils does not
# support mixing assembler and LTO code in the same ld -r object.
# XXX check if the gcc plugin ld is the expected one too
# XXX some Fedora binutils should also support it. How to check for that?
ifeq ($(call ld-ifversion,-ge,22710001,y),y)
...
However, GCC LTO was not merged into the mainline after all.
(https://lkml.org/lkml/2014/4/8/272)
So, the 4th and 5th fields were never used, and finally removed by
commit 0d61ed17dd ("ld-version: Drop the 4th and 5th version
components").
Since then, the last 4-digits returned by this script is always zeros.
Remove the meaningless last 4-digits. This makes the version format
consistent with GCC_VERSION, CLANG_VERSION, LLD_VERSION.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Currently, when linking with ld.lld, this warning pops up:
arch/mips/vdso/Makefile:70: MIPS VDSO requires binutils >= 2.25
CONFIG_LD_VERSION is set with scripts/ld-version.sh, which is specific
to GNU ld. It returns 0 for ld.lld so CONFIG_MIPS_LD_CAN_LINK_VDSO does
not set.
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 block so it should be allowed to link the VDSO.
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
Reported-by: Dmitry Golovin <dima@golovin.in>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/785
Link: e364e2e9ce
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
After commit 9553d16fa6 ("init/kconfig: Add LD_VERSION Kconfig"), we
have access to GNU ld's version at configuration time. As a result, we
can make it clearer under what configuration circumstances the MIPS VDSO
needs to be disabled.
This is a prerequisite for getting rid of the MIPS VDSO binutils
warning and linking the VDSO when LD is ld.lld. Wrapping the call to
ld-ifversion with CONFIG_LD_IS_LLD does not work because the config
values are wiped away during 'make clean'.
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
