On 02.04.2025 10:51, Jan Beulich wrote: > In GNU ld --disable-reloc-section implies --disable-dynamicbase (and > also --disable-high-entropy-va, just fyi). Therefore to yield > functionally identical binaries independent of whether mkreloc needs to > come into play, add --dynamicbase as well. > > GNU ld further defaults to --high-entropy-va (along with --dynamicbase > and --nxcompat) unless "Cygwin-like". This seems wrong to me; that > default should be dependent upon "MinGW-like" instead; for the purpose > of building EFI binaries with a PE32+-capable ELF linker neither > "Cygwin-like" nor "MinGW-like" ought to be true. We certainly don't mean > to have this bit set in the DLL characteristics, so suppress its > setting. > > Sadly while --high-entropy-va is supported by GNU ld 2.25, > --disable-high-entropy-va was introduced only in 2.36. Luckily the > defaulting to --high-entropy-va was also only introduced in 2.36. Plus > --disable-reloc-section was introduced precisely there, too. Hence > leverage the probing we do as to base relocation generation, to also > determine whether to pass --disable-high-entropy-va. > > Signed-off-by: Jan Beulich <jbeul...@suse.com>
Despite the file being modified suggesting this needs an x86 maintainer ack, I think it's rather one of the two of you who should ack (or otherwise comment on) this. Jan > --- > I remain uncertain about the applicability of DLL characteristics to > non-DLLs, i.e. images without IMAGE_FILE_DLL set; current MS doc says > nothing either way. Yet producing consistent binaries still seems > desirable, even if the field wasn't to be used by loaders. > > --- a/xen/arch/x86/arch.mk > +++ b/xen/arch/x86/arch.mk > @@ -113,6 +113,7 @@ efi-nr-fixups := $(shell LC_ALL=C $(OBJD > > ifeq ($(efi-nr-fixups),2) > MKRELOC := : > +EFI_LDFLAGS += --disable-high-entropy-va > else > MKRELOC := arch/x86/efi/mkreloc > # If the linker produced fixups but not precisely two of them, we need to > @@ -123,6 +124,8 @@ EFI_LDFLAGS += --disable-reloc-section > endif > endif > > +EFI_LDFLAGS += --dynamicbase > + > endif # $(XEN_BUILD_PE) > > export XEN_BUILD_EFI XEN_BUILD_PE
