Hi Daniel, On Fri, Jun 8, 2018 at 11:33 AM, Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote: > On 06/08/2018 10:57 AM, Geert Uytterhoeven wrote: >> On Mon, May 28, 2018 at 5:31 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: >>> When build testing across architectures, I run into a build error on >>> all targets other than X86: >>> >>> gcc-8.1.0-nolibc/arm-linux-gnueabi/bin/arm-linux-gnueabi-objdump: net/bpfilter/bpfilter_umh: File format not recognized >>> gcc-8.1.0-nolibc/arm-linux-gnueabi/bin/arm-linux-gnueabi-objcopy:net/bpfilter/bpfilter_umh.o: Invalid bfd target >>> >>> The problem is that 'hostprogs' get built with 'gcc' rather than >>> '$(CROSS_COMPILE)gcc', and my default gcc (as most people's) targets x86. >>> >>> To work around it, adding an X86 dependency gets randconfigs building >>> again on my box. >>> >>> Clearly, this is not a good solution, since it should actually work fine >>> when building native kernels on other architectures but that is now >>> disabled, while cross building an x86 kernel on another host is still >>> broken after my patch. >>> >>> What we probably want here is to try out if the compiler is able to build >>> executables for the target architecture and not build the helper otherwise, >>> at least when compile-testing. No idea how to do that though. >> >> So that was done in commit 819dd92b9c0bc7bc ("bpfilter: switch to CC >> from HOSTCC"), but it is not sufficient: >> >> GEN net/bpfilter/bpfilter_umh.o >> Usage: m68k-linux-gnu-objcopy [option(s)] in-file [out-file] >> Copies a binary file, possibly transforming it in the process >> The options are: >> [...] >> >> net/bpfilter/Makefile:29: recipe for target 'net/bpfilter/bpfilter_umh.o' failed >> make[5]: *** [net/bpfilter/bpfilter_umh.o] Error 1 >> >>> --- a/net/bpfilter/Kconfig >>> +++ b/net/bpfilter/Kconfig >>> @@ -9,6 +9,7 @@ menuconfig BPFILTER >>> if BPFILTER >>> config BPFILTER_UMH >>> tristate "bpfilter kernel module with user mode helper" >>> + depends on X86 # actually depends on native builds >> >> No, (currently) it does depend on X86, due to its use of: >> >> $(OBJCOPY) -I binary -O $(CONFIG_OUTPUT_FORMAT) >> >> with CONFIG_OUTPUT_FORMAT being defined on X86 only... > > That hard dependency should have been fixed with the following patch in -net tree: > > https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/commit/?id=8d97ca6b6755bf7ef57d323642ca9ee80d689782 Thanks, confirmed. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- 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