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configure: Replace -Wl,-r,-d with -Wl,-r and add -fno-common

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In GNU ld and ld.lld, -d is used with -r to allocate space to COMMON symbols.
This behavior is presumably to work around legacy projects which inspect
relocatable output by themselves and do not handle COMMON symbols. The GRUB
does not do this.

See https://github.com/llvm/llvm-project/issues/53660
-d is quite useless and ld.lld 15.0.0 will make -d no-op.

COMMON symbols have special symbol resolution semantics which can cause surprise
(see https://maskray.me/blog/2022-02-06-all-about-common-symbols). GCC<10 and
Clang<11 defaulted to -fcommon. Just use -fno-common to avoid COMMON symbols.

Signed-off-by: Fangrui Song <maskray@google.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Fangrui Song 2022-02-11 10:13:23 -08:00 committed by Daniel Kiper
parent 5e10be48e5
commit b16257b51b
5 changed files with 17 additions and 17 deletions
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2
acinclude.m4
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@ -430,7 +430,7 @@ link_nopie_needed=no]
AC_MSG_CHECKING([whether linker needs disabling of PIE to work])
AC_LANG_CONFTEST([AC_LANG_SOURCE([[]])])
[if eval "$ac_compile -Wl,-r,-d -nostdlib -Werror -o conftest.o" 2> /dev/null; then]
[if eval "$ac_compile -Wl,-r -nostdlib -Werror -o conftest.o" 2> /dev/null; then]
AC_MSG_RESULT([no])
[# Should we clear up other files as well, having called `AC_LANG_CONFTEST'?
rm -f conftest.o

2
conf/Makefile.common
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@ -41,7 +41,7 @@ CCASFLAGS_KERNEL = $(CCASFLAGS_CPU) $(CCASFLAGS_PLATFORM)
STRIPFLAGS_KERNEL = -R .rel.dyn -R .reginfo -R .note -R .comment -R .drectve -R .note.gnu.gold-version -R .MIPS.abiflags -R .ARM.exidx
CFLAGS_MODULE = $(CFLAGS_PLATFORM) -ffreestanding
LDFLAGS_MODULE = $(LDFLAGS_PLATFORM) -nostdlib $(TARGET_LDFLAGS_OLDMAGIC) -Wl,-r,-d
LDFLAGS_MODULE = $(LDFLAGS_PLATFORM) -nostdlib $(TARGET_LDFLAGS_OLDMAGIC) -Wl,-r
CPPFLAGS_MODULE = $(CPPFLAGS_CPU) $(CPPFLAGS_PLATFORM)
CCASFLAGS_MODULE = $(CCASFLAGS_CPU) $(CCASFLAGS_PLATFORM)

6
configure.ac
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@ -85,9 +85,9 @@ fi
# Enable support for "restrict" keyword and other
# features from gnu99 C language standard.
BUILD_CFLAGS="-std=gnu99 $BUILD_CFLAGS"
HOST_CFLAGS="-std=gnu99 $HOST_CFLAGS"
TARGET_CFLAGS="-std=gnu99 $TARGET_CFLAGS"
BUILD_CFLAGS="-std=gnu99 -fno-common $BUILD_CFLAGS"
HOST_CFLAGS="-std=gnu99 -fno-common $HOST_CFLAGS"
TARGET_CFLAGS="-std=gnu99 -fno-common $TARGET_CFLAGS"
# Default HOST_CPPFLAGS
HOST_CPPFLAGS="$HOST_CPPFLAGS -Wall -W"

20
grub-core/Makefile.core.def
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@ -49,26 +49,26 @@ kernel = {
nostrip = emu;
emu_ldflags = '-Wl,-r,-d';
i386_efi_ldflags = '-Wl,-r,-d';
emu_ldflags = '-Wl,-r';
i386_efi_ldflags = '-Wl,-r';
i386_efi_stripflags = '--strip-unneeded -K start -R .note -R .comment -R .note.gnu.gold-version';
x86_64_efi_ldflags = '-Wl,-r,-d';
x86_64_efi_ldflags = '-Wl,-r';
x86_64_efi_stripflags = '--strip-unneeded -K start -R .note -R .comment -R .note.gnu.gold-version';
ia64_efi_cflags = '-fno-builtin -fpic -minline-int-divide-max-throughput';
ia64_efi_ldflags = '-Wl,-r,-d';
ia64_efi_ldflags = '-Wl,-r';
ia64_efi_stripflags = '--strip-unneeded -K start -R .note -R .comment -R .note.gnu.gold-version';
arm_efi_ldflags = '-Wl,-r,-d';
arm_efi_ldflags = '-Wl,-r';
arm_efi_stripflags = '--strip-unneeded -K start -R .note -R .comment -R .note.gnu.gold-version';
arm64_efi_ldflags = '-Wl,-r,-d';
arm64_efi_ldflags = '-Wl,-r';
arm64_efi_stripflags = '--strip-unneeded -K start -R .note -R .comment -R .note.gnu.gold-version -R .eh_frame';
riscv32_efi_ldflags = '-Wl,-r,-d';
riscv32_efi_ldflags = '-Wl,-r';
riscv32_efi_stripflags = '--strip-unneeded -K start -R .note -R .comment -R .note.gnu.gold-version -R .eh_frame';
riscv64_efi_ldflags = '-Wl,-r,-d';
riscv64_efi_ldflags = '-Wl,-r';
riscv64_efi_stripflags = '--strip-unneeded -K start -R .note -R .comment -R .note.gnu.gold-version -R .eh_frame';
i386_pc_ldflags = '$(TARGET_IMG_LDFLAGS)';
@ -98,9 +98,9 @@ kernel = {
i386_qemu_cppflags = '-DGRUB_BOOT_MACHINE_LINK_ADDR=$(GRUB_BOOT_MACHINE_LINK_ADDR)';
emu_cflags = '$(CFLAGS_GNULIB)';
emu_cppflags = '$(CPPFLAGS_GNULIB)';
arm_uboot_ldflags = '-Wl,-r,-d';
arm_uboot_ldflags = '-Wl,-r';
arm_uboot_stripflags = '--strip-unneeded -K start -R .note -R .comment -R .note.gnu.gold-version';
arm_coreboot_ldflags = '-Wl,-r,-d';
arm_coreboot_ldflags = '-Wl,-r';
arm_coreboot_stripflags = '--strip-unneeded -K start -R .note -R .comment -R .note.gnu.gold-version';
i386_pc_startup = kern/i386/pc/startup.S;

4
grub-core/genmod.sh.in
View File

@ -83,9 +83,9 @@ else
for dep in $deps; do echo "char moddep_$dep[] __attribute__ ((section(\"_moddeps, _moddeps\"))) = \"$dep\";" >>$t2; done
if test -n "$deps"; then
@TARGET_CC@ @TARGET_LDFLAGS@ -ffreestanding -nostdlib -o $tmpfile2 $t1 $t2 $tmpfile -Wl,-r,-d
@TARGET_CC@ @TARGET_LDFLAGS@ -ffreestanding -nostdlib -o $tmpfile2 $t1 $t2 $tmpfile -Wl,-r
else
@TARGET_CC@ @TARGET_LDFLAGS@ -ffreestanding -nostdlib -o $tmpfile2 $t1 $tmpfile -Wl,-r,-d
@TARGET_CC@ @TARGET_LDFLAGS@ -ffreestanding -nostdlib -o $tmpfile2 $t1 $tmpfile -Wl,-r
fi
rm -f $t1 $t2 $tmpfile
mv $tmpfile2 $tmpfile