On Sat, 5 Dec 2015 00:18:47 +0800 kbuild test robot <fengguang.wu@xxxxxxxxx> wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > head: dcccebc04ddba852aad354270986d508e8f011c0 > commit: a8f025e63718534d6a9224a0b069b772ef21cb5d [4174/4356] arm: mm: support ARCH_MMAP_RND_BITS > config: arm-vf610m4_defconfig (attached as .config) > reproduce: > wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > git checkout a8f025e63718534d6a9224a0b069b772ef21cb5d > # save the attached .config to linux build tree > make.cross ARCH=arm > > All errors (new ones prefixed by >>): > > >> kernel/built-in.o:(.data+0x754): undefined reference to `mmap_rnd_bits' > >> kernel/built-in.o:(.data+0x76c): undefined reference to `mmap_rnd_bits_min' > >> kernel/built-in.o:(.data+0x770): undefined reference to `mmap_rnd_bits_max' OK, the patches are pretty broken when HAVE_ARCH_MMAP_RND_BITS=n. I guess a pile of new ifdefs need adding for this case. There's also the matter of CONFIG_MMU=n. mm/mmap.o doesn't get included in the build in this case, so that will also break things. I suggest that can be fixed by making HAVE_ARCH_MMAP_RND_BITS and HAVE_ARCH_MMAP_RND_COMPAT_BITS depend on MMU. That should fix things up when combined with the new ifdef-sprinkling. This stuff is going to break quite a lot of test builds so I think I'll consolidate the patches then drop 'em for now. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>