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

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>

5 files changed, 17 insertions, 17 deletions

diff --git a/acinclude.m4 b/acinclude.m4
index 6e14bb553..fa7840f09 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -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
diff --git a/conf/Makefile.common b/conf/Makefile.common
index b19b98ee9..b343a038e 100644
--- a/conf/Makefile.common
+++ b/conf/Makefile.common
@@ -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)
 
diff --git a/configure.ac b/configure.ac
index 5c01af0fa..d1eaafee1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -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"
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 8022e1c0a..ac00cc8a2 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -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;
diff --git a/grub-core/genmod.sh.in b/grub-core/genmod.sh.in
index 1250589b3..e57c4d920 100644
--- a/grub-core/genmod.sh.in
+++ b/grub-core/genmod.sh.in
@@ -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