On Thu, 22 Jun 2017 14:33:27 +1000 Nicholas Piggin <npiggin@xxxxxxxxx> wrote: > On Thu, 22 Jun 2017 11:48:38 +0800 > kbuild test robot <fengguang.wu@xxxxxxxxx> wrote: > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git thin-ar > > head: f9aac183deb53716ea92f528595758e3c9ef3539 > > commit: c5784ad98b773d08562a34b700e9c5e84763c0d8 [5/8] ia64: thin archives fix linking > > config: ia64-allnoconfig (attached as .config) > > compiler: ia64-linux-gcc (GCC) 6.2.0 > > reproduce: > > wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > > chmod +x ~/bin/make.cross > > git checkout c5784ad98b773d08562a34b700e9c5e84763c0d8 > > # save the attached .config to linux build tree > > make.cross ARCH=ia64 > > > > All warnings (new ones prefixed by >>): > > > > >> ia64-linux-ld: warning: .note.gnu.build-id section discarded, --build-id ignored. > > > Sigh. > > What's happening here is that when performing the final link with the > -R option, the linker forgets to emit the --build-id section it was > asked to. > > This is the final link command line that causes the error: > > $ ia64-linux-ld -static -R arch/ia64/kernel/gate-syms.o --build-id -o vmlinux -T ./arch/ia64/kernel/vmlinux.lds --whole-archive built-in.o --no-whole-archive --start-group lib/lib.a arch/ia64/lib/lib.a --end-group > > However it links successfully if I do this: > > $ ia64-linux/bin/ia64-linux-ld -r -R arch/ia64/kernel/gate-syms.o -o syms.o > $ ia64-linux/bin/ia64-linux-ld -static syms.o --build-id -o vmlinux -T ./arch/ia64/kernel/vmlinux.lds --whole-archive built-in.o --no-whole-archive --start-group lib/lib.a arch/ia64/lib/lib.a --end-group > > I.e., create an intermediate object file with the symbols first using > symbols from gate-syms.o, and use that in the final link rather than -R > > Alan do you have any idea what the problem might be here? > > If it turns out to be a toolchain bug or limitation, I can do the same > workaround in the kernel. Here is the fix for the kernel for ia64 (tile and sh would have to follow). This creates a .o file with the gate symbols and then that is used for the final link input (rather than -R symbol file). I think this is actually the right way to go about it. I'll resend new patches for the 3 archs unless there is another suggestion. Thanks, Nick --- arch/ia64/kernel/Makefile.gate | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/ia64/kernel/Makefile.gate b/arch/ia64/kernel/Makefile.gate index a32903ada016..f89219e20b25 100644 --- a/arch/ia64/kernel/Makefile.gate +++ b/arch/ia64/kernel/Makefile.gate @@ -2,7 +2,9 @@ targets += gate.so gate-syms.o -extra-y += gate.so gate-syms.o gate.lds gate.o +obj-y += gate-syms.o + +extra-y += gate.so gate.lds gate.o CPPFLAGS_gate.lds := -P -C -U$(ARCH) @@ -14,14 +16,15 @@ GATECFLAGS_gate.so = -shared -s -Wl,-soname=linux-gate.so.1 \ $(obj)/gate.so: $(obj)/gate.lds $(obj)/gate.o FORCE $(call if_changed,gate) -$(obj)/built-in.o: $(obj)/gate-syms.o -$(obj)/built-in.o: ld_flags += -R $(obj)/gate-syms.o +# create an object file to resolve gate symbols +quiet_cmd_gate_syms = GATE $@ + cmd_gate_syms = $(LD) -r -T $(obj)/gate.lds -R $(obj)/gate.o -o$(obj)/gate-syms.o -GATECFLAGS_gate-syms.o = -r $(obj)/gate-syms.o: $(obj)/gate.lds $(obj)/gate.o FORCE - $(call if_changed,gate) + $(call if_changed,gate_syms) # gate-data.o contains the gate DSO image as data in section .data..gate. # We must build gate.so before we can assemble it. # Note: kbuild does not track this dependency due to usage of .incbin $(obj)/gate-data.o: $(obj)/gate.so + -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
