[PATCH] scripts/tools-support-relr.sh: un-quote variables

From: Ilie Halip
Date: Tue Nov 12 2019 - 08:45:39 EST


When the CC variable contains quotes, e.g. when using
ccache (make CC="ccache <compiler>"), this script always
fails, so CONFIG_RELR is never enabled, even when the
toolchain supports this feature. Removing the /dev/null
redirect and invoking the script manually shows the issue:

$ CC='/usr/bin/ccache clang' ./scripts/tools-support-relr.sh
./scripts/tools-support-relr.sh: 7: ./scripts/tools-support-relr.sh: /usr/bin/ccache clang: not found

Fix this by un-quoting the variables.

Before:
$ make ARCH=arm64 CC='/usr/bin/ccache clang' LD=ld.lld \
NM=llvm-nm OBJCOPY=llvm-objcopy defconfig
$ grep RELR .config
CONFIG_ARCH_HAS_RELR=y

With this change:
$ make ARCH=arm64 CC='/usr/bin/ccache clang' LD=ld.lld \
NM=llvm-nm OBJCOPY=llvm-objcopy defconfig
$ grep RELR .config
CONFIG_TOOLS_SUPPORT_RELR=y
CONFIG_ARCH_HAS_RELR=y
CONFIG_RELR=y

Fixes: 5cf896fb6be3 ("arm64: Add support for relocating the kernel with RELR relocations")
Reported-by: Dmitry Golovin <dima@xxxxxxxxxx>
Link: https://github.com/ClangBuiltLinux/linux/issues/769
Cc: Peter Collingbourne <pcc@xxxxxxxxxx>
Signed-off-by: Ilie Halip <ilie.halip@xxxxxxxxx>
---
scripts/tools-support-relr.sh | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/scripts/tools-support-relr.sh b/scripts/tools-support-relr.sh
index 97a2c844a95e..45e8aa360b45 100755
--- a/scripts/tools-support-relr.sh
+++ b/scripts/tools-support-relr.sh
@@ -4,13 +4,13 @@
tmp_file=$(mktemp)
trap "rm -f $tmp_file.o $tmp_file $tmp_file.bin" EXIT

-cat << "END" | "$CC" -c -x c - -o $tmp_file.o >/dev/null 2>&1
+cat << "END" | $CC -c -x c - -o $tmp_file.o >/dev/null 2>&1
void *p = &p;
END
-"$LD" $tmp_file.o -shared -Bsymbolic --pack-dyn-relocs=relr -o $tmp_file
+$LD $tmp_file.o -shared -Bsymbolic --pack-dyn-relocs=relr -o $tmp_file

# Despite printing an error message, GNU nm still exits with exit code 0 if it
# sees a relr section. So we need to check that nothing is printed to stderr.
-test -z "$("$NM" $tmp_file 2>&1 >/dev/null)"
+test -z "$($NM $tmp_file 2>&1 >/dev/null)"

-"$OBJCOPY" -O binary $tmp_file $tmp_file.bin
+$OBJCOPY -O binary $tmp_file $tmp_file.bin
--
2.17.1