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 way debuginfo built from the .module will still include this
information, but the final result won't have the data we don't actually
need in the modules, either on-disk, loaded at runtime, or in prebuilt
images.
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
On emu some checks can be laxer like check for relocation range. Additionally
module loading in emu is rarely used. So skip this check rather than making
it laxer for all platforms. In ideal we may want to have slightly different
check for emu but for now this is good enough.
This section is generated by clang and is useful only for debugging.
It contains exotic relocations, so strip them to avoid them interferring
with module loading.
* acinclude.m4: Determine whether nm support -P and --defined-only.
* configure.ac: Add TARGET_ to all variables pertaining to target
that don't have it yet.
* gentpl.py: Likewise.
* grub-core/Makefile.am: Likewise.
* grub-core/genmod.sh.in: Likewise.
* grub-core/gensyminfo.sh.in: Handle OpenBSD and other non-GNU nm
as well.
* conf/Makefile.common (STRIPFLAGS_KERNEL): Add -F elf32-i386 and
-R .drectve on cygwin.
* conf/i386-pc-cygwin-img-ld.sc: Merge rdata and pdata into data.
* configure.ac: Use $(top_builddir) in TARGET_OBJ2ELF.
(COND_CYGWIN): New condition.
* grub-core/Makefile.am (%.mod): Set TARGET_OBJ2ELF.
* grub-core/genmod.sh.in: Use ${TARGET_OBJ2ELF} and
not @TARGET_OBJ2ELF@.
* util/grub-pe2elf.c (write_symbol_table): Use pe_symtab->type and not
type to determine whether aux is to be used.
