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[Xen-changelog] [xen stable-4.12] x86: fix race to build arch/x86/efi/relocs-dummy.o

Date: Tue, 26 Nov 2019 10:02:34 +0000

Delivery-date: Tue, 26 Nov 2019 10:02:38 +0000

List-id: "Change log for Mercurial $receive only$" <xen-changelog.lists.xenproject.org>

commit 18f988a7ce0414f5b621c759a14a0d0bf231a3fd Author: Anthony PERARD <anthony.perard@xxxxxxxxxx> AuthorDate: Mon Nov 25 16:03:12 2019 +0100 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Mon Nov 25 16:03:12 2019 +0100 x86: fix race to build arch/x86/efi/relocs-dummy.o With $(TARGET).efi depending on efi/relocs-dummy.o, arch/x86/Makefile will attempt to build that object. This may result in a dependency file being generated that has relocs-dummy.o depending on efi/relocs-dummy.S. Then, when arch/x86/efi/Makefile tries to build relocs-dummy.o, well efi/relocs-dummy.S doesn't exist. Have only one makefile responsible for building relocs-dummy.o. Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> x86/Makefile: remove $(guard) use from $(TARGET).efi target Following the patch 65d104984c04 ("x86: fix race to build arch/x86/efi/relocs-dummy.o"), the error message nm: 'efi/relocs-dummy.o': No such file" started to appear on system which can't build the .efi target. This is because relocs-dummy.o isn't built anymore. The error is printed by the evaluation of VIRT_BASE and ALT_BASE which aren't use anyway. But, we don't need that file as we don't want to build `$(TARGET).efi' anyway. On such system, $(guard) evaluate to the shell builtin ':', which prevent any of the shell commands in `$(TARGET).efi' from been executed. Even if $(guard) is evaluated opon use, it depends on $(XEN_BUILD_PE) which is evaluated at the assignment. So, we can replace $(guard) in $(TARGET).efi by having two different rules depending on $(XEN_BUILD_PE) instead. The change with this patch is that none of the dependency of $(TARGET).efi will be built if the linker doesn't support PE and VIRT_BASE and ALT_BASE don't get evaluated anymore, so nm will not complain about the missing relocs-dummy.o file anymore. Since prelink-efi.o isn't built on system that can't build $(TARGET).efi anymore, we can remove the $(guard) variable everywhere. Reported-by: Jan Beulich <jbeulich@xxxxxxxx> Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> master commit: 65d104984c04e69234f77bd3b8f8c0ef85b3f7fa master date: 2019-11-15 14:18:16 +0100 master commit: 7059afb202ff0d82a6fa94f7ef84e4bb3139914e master date: 2019-11-20 17:12:12 +0100 --- xen/arch/x86/Makefile | 44 +++++++++++++++++++++++--------------------- 1 file changed, 23 insertions(+), 21 deletions(-) diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile index 9b9a4435fb..a53bdcf979 100644 --- a/xen/arch/x86/Makefile +++ b/xen/arch/x86/Makefile @@ -112,20 +112,20 @@ prelink_lto.o: $(ALL_OBJS) $(LD_LTO) -r -o $@ $^ prelink-efi_lto.o: $(ALL_OBJS) efi/runtime.o efi/compat.o - $(guard) $(LD_LTO) -r -o $@ $(filter-out %/efi/built_in.o,$^) + $(LD_LTO) -r -o $@ $(filter-out %/efi/built_in.o,$^) # Link it with all the binary objects prelink.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink_lto.o $(LD) $(LDFLAGS) -r -o $@ $^ prelink-efi.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink-efi_lto.o efi/boot.init.o - $(guard) $(LD) $(LDFLAGS) -r -o $@ $^ + $(LD) $(LDFLAGS) -r -o $@ $^ else prelink.o: $(ALL_OBJS) $(LD) $(LDFLAGS) -r -o $@ $^ prelink-efi.o: $(ALL_OBJS) efi/boot.init.o efi/runtime.o efi/compat.o - $(guard) $(LD) $(LDFLAGS) -r -o $@ $(filter-out %/efi/built_in.o,$^) + $(LD) $(LDFLAGS) -r -o $@ $(filter-out %/efi/built_in.o,$^) endif $(TARGET)-syms: prelink.o xen.lds @@ -170,8 +170,6 @@ CFLAGS-$(XEN_BUILD_EFI) += -DXEN_BUILD_EFI $(TARGET).efi: VIRT_BASE = 0x$(shell $(NM) efi/relocs-dummy.o | sed -n 's, A VIRT_START$$,,p') $(TARGET).efi: ALT_BASE = 0x$(shell $(NM) efi/relocs-dummy.o | sed -n 's, A ALT_START$$,,p') -# Don't use $(wildcard ...) here - at least make 3.80 expands this too early! -$(TARGET).efi: guard = $(if $(filter y,$(XEN_BUILD_PE)),,:) ifneq ($(build_id_linker),) ifeq ($(call ld-ver-build-id,$(LD) $(filter -m%,$(EFI_LDFLAGS))),y) @@ -189,30 +187,34 @@ note_file := endif note_file_option ?= $(note_file) +ifeq ($(filter y,$(XEN_BUILD_PE)),y) $(TARGET).efi: prelink-efi.o $(note_file) efi.lds efi/relocs-dummy.o efi/mkreloc $(foreach base, $(VIRT_BASE) $(ALT_BASE), \ - $(guard) $(LD) $(call EFI_LDFLAGS,$(base)) -T efi.lds -N $< efi/relocs-dummy.o \ + $(LD) $(call EFI_LDFLAGS,$(base)) -T efi.lds -N $< efi/relocs-dummy.o \ $(BASEDIR)/common/symbols-dummy.o $(note_file_option) -o $(@D)/.$(@F).$(base).0 &&) : - $(guard) efi/mkreloc $(foreach base,$(VIRT_BASE) $(ALT_BASE),$(@D)/.$(@F).$(base).0) >$(@D)/.$(@F).0r.S - $(guard) $(NM) -pa --format=sysv $(@D)/.$(@F).$(VIRT_BASE).0 \ - | $(guard) $(BASEDIR)/tools/symbols $(all_symbols) --sysv --sort >$(@D)/.$(@F).0s.S - $(guard) $(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).0r.o $(@D)/.$(@F).0s.o + efi/mkreloc $(foreach base,$(VIRT_BASE) $(ALT_BASE),$(@D)/.$(@F).$(base).0) >$(@D)/.$(@F).0r.S + $(NM) -pa --format=sysv $(@D)/.$(@F).$(VIRT_BASE).0 \ + | $(BASEDIR)/tools/symbols $(all_symbols) --sysv --sort >$(@D)/.$(@F).0s.S + $(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).0r.o $(@D)/.$(@F).0s.o $(foreach base, $(VIRT_BASE) $(ALT_BASE), \ - $(guard) $(LD) $(call EFI_LDFLAGS,$(base)) -T efi.lds -N $< \ + $(LD) $(call EFI_LDFLAGS,$(base)) -T efi.lds -N $< \ $(@D)/.$(@F).0r.o $(@D)/.$(@F).0s.o $(note_file_option) -o $(@D)/.$(@F).$(base).1 &&) : - $(guard) efi/mkreloc $(foreach base,$(VIRT_BASE) $(ALT_BASE),$(@D)/.$(@F).$(base).1) >$(@D)/.$(@F).1r.S - $(guard) $(NM) -pa --format=sysv $(@D)/.$(@F).$(VIRT_BASE).1 \ - | $(guard) $(BASEDIR)/tools/symbols $(all_symbols) --sysv --sort >$(@D)/.$(@F).1s.S - $(guard) $(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).1r.o $(@D)/.$(@F).1s.o - $(guard) $(LD) $(call EFI_LDFLAGS,$(VIRT_BASE)) -T efi.lds -N $< \ + efi/mkreloc $(foreach base,$(VIRT_BASE) $(ALT_BASE),$(@D)/.$(@F).$(base).1) >$(@D)/.$(@F).1r.S + $(NM) -pa --format=sysv $(@D)/.$(@F).$(VIRT_BASE).1 \ + | $(BASEDIR)/tools/symbols $(all_symbols) --sysv --sort >$(@D)/.$(@F).1s.S + $(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).1r.o $(@D)/.$(@F).1s.o + $(LD) $(call EFI_LDFLAGS,$(VIRT_BASE)) -T efi.lds -N $< \ $(@D)/.$(@F).1r.o $(@D)/.$(@F).1s.o $(note_file_option) -o $@ - if $(guard) false; then rm -f $@; echo 'EFI support disabled'; \ - else $(NM) -pa --format=sysv $(@D)/$(@F) \ - | $(BASEDIR)/tools/symbols --xensyms --sysv --sort >$(@D)/$(@F).map; fi + $(NM) -pa --format=sysv $(@D)/$(@F) \ + | $(BASEDIR)/tools/symbols --xensyms --sysv --sort >$(@D)/$(@F).map rm -f $(@D)/.$(@F).[0-9]* $(@D)/..$(@F).[0-9]* +else +$(TARGET).efi: FORCE + rm -f $@; echo 'EFI support disabled' +endif -efi/boot.init.o efi/runtime.o efi/compat.o efi/buildid.o: $(BASEDIR)/arch/x86/efi/built_in.o -efi/boot.init.o efi/runtime.o efi/compat.o efi/buildid.o: ; +efi/boot.init.o efi/runtime.o efi/compat.o efi/buildid.o efi/relocs-dummy.o: $(BASEDIR)/arch/x86/efi/built_in.o +efi/boot.init.o efi/runtime.o efi/compat.o efi/buildid.o efi/relocs-dummy.o: ; asm-offsets.s: $(TARGET_SUBARCH)/asm-offsets.c $(BASEDIR)/include/asm-x86/asm-macros.h $(CC) $(filter-out -Wa$(comma)% -flto,$(CFLAGS)) -S -o $@ $< -- generated by git-patchbot for /home/xen/git/xen.git#stable-4.12 _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/xen-changelog

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