kbuild: Disable CONFIG_LD_ORPHAN_WARN for ld.lld 10.0.1

ld.lld 10.0.1 spews a bunch of various warnings about .rela sections,
along with a few others. Newer versions of ld.lld do not have these
warnings. As a result, do not add '--orphan-handling=warn' to
LDFLAGS_vmlinux if ld.lld's version is not new enough.

Link: https://github.com/ClangBuiltLinux/linux/issues/1187
Link: https://github.com/ClangBuiltLinux/linux/issues/1193
Reported-by: Arvind Sankar <nivedita@alum.mit.edu>
Reported-by: kernelci.org bot <bot@kernelci.org>
Reported-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This commit is contained in:
Nathan Chancellor 2020-11-19 13:46:58 -07:00 committed by Masahiro Yamada
parent 59612b24f7
commit d5750cd3c5
3 changed files with 26 additions and 0 deletions

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@ -4274,6 +4274,7 @@ B: https://github.com/ClangBuiltLinux/linux/issues
C: irc://chat.freenode.net/clangbuiltlinux
F: Documentation/kbuild/llvm.rst
F: scripts/clang-tools/
F: scripts/lld-version.sh
K: \b(?i:clang|llvm)\b
CLEANCACHE API

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@ -47,6 +47,10 @@ config CLANG_VERSION
int
default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
config LLD_VERSION
int
default $(shell,$(srctree)/scripts/lld-version.sh $(LD))
config CC_CAN_LINK
bool
default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT
@ -1351,6 +1355,7 @@ config LD_DEAD_CODE_DATA_ELIMINATION
config LD_ORPHAN_WARN
def_bool y
depends on ARCH_WANT_LD_ORPHAN_WARN
depends on !LD_IS_LLD || LLD_VERSION >= 110000
depends on $(ld-option,--orphan-handling=warn)
config SYSCTL

20
scripts/lld-version.sh Executable file
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@ -0,0 +1,20 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
#
# Usage: $ ./scripts/lld-version.sh ld.lld
#
# Print the linker version of `ld.lld' in a 5 or 6-digit form
# such as `100001' for ld.lld 10.0.1 etc.
linker_string="$($* --version)"
if ! ( echo $linker_string | grep -q LLD ); then
echo 0
exit 1
fi
VERSION=$(echo $linker_string | cut -d ' ' -f 2)
MAJOR=$(echo $VERSION | cut -d . -f 1)
MINOR=$(echo $VERSION | cut -d . -f 2)
PATCHLEVEL=$(echo $VERSION | cut -d . -f 3)
printf "%d%02d%02d\\n" $MAJOR $MINOR $PATCHLEVEL