Hey Al, Michal, I can confirm Olivers issue, the current mainline kernel fails to boot on kernels with CONFIG_MODVERSIONS=y. Bisection points to: commit 784d5699eddc55878627da20d3fe0c8542e2f1a2 Author: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Date: Mon Jan 11 11:04:34 2016 -0500 x86: move exports to actual definitions Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Good builds have a non-zero address in Module.symvers: 0x69acdf38 memcpy vmlinux EXPORT_SYMBOL Bad builds have a zero address here: 0x00000000 memcpy vmlinux EXPORT_SYMBOL This was encountered on Arch Linux with GCC 6.2.1 and Linux v4.9-rc2-40-g9fe68ca. Note that the identified commit above cannot be reverted cleanly on master. Kind regards, Peter On Fri, Oct 21, 2016 at 06:23:57PM +0200, Oliver Hartkopp wrote: > Hello Michal, > > I waited some days for a fix - but obviously no one else has this problem so > far ... > > This merge > > "Merge branch 'kbuild' of > git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild" > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=84d69848c97faab0c25aa2667b273404d2e2a64a > > creates a bunch of warnings on my system and the built kernel does not boot > (it complains about a missing root fs). > > In the build process some .ko files are built fine and some don't: > > (..) > MODPOST 176 modules > AS arch/x86/boot/compressed/efi_thunk_64.o > GZIP arch/x86/boot/compressed/vmlinux.bin.gz > CC arch/x86/boot/compressed/misc.o > WARNING: "memset" [sound/usb/snd-usbmidi-lib.ko] has no CRC! > WARNING: "__fentry__" [sound/usb/snd-usbmidi-lib.ko] has no CRC! > WARNING: "memcpy" [sound/usb/snd-usbmidi-lib.ko] has no CRC! > WARNING: "__sw_hweight32" [sound/usb/snd-usbmidi-lib.ko] has no CRC! > WARNING: "_copy_to_user" [sound/usb/snd-usb-audio.ko] has no CRC! > WARNING: "memset" [sound/usb/snd-usb-audio.ko] has no CRC! > WARNING: "__put_user_1" [sound/usb/snd-usb-audio.ko] has no CRC! > WARNING: "__put_user_4" [sound/usb/snd-usb-audio.ko] has no CRC! > WARNING: "__fentry__" [sound/usb/snd-usb-audio.ko] has no CRC! > WARNING: "memcpy" [sound/usb/snd-usb-audio.ko] has no CRC! > WARNING: "__fentry__" [sound/soundcore.ko] has no CRC! > (..) > WARNING: "__fentry__" [arch/x86/crypto/crc32c-intel.ko] has no CRC! > WARNING: "__fentry__" [arch/x86/crypto/crc32-pclmul.ko] has no CRC! > WARNING: "__fentry__" [arch/x86/crypto/aesni-intel.ko] has no CRC! > WARNING: "__fentry__" [arch/x86/crypto/aes-x86_64.ko] has no CRC! > CC arch/x86/crypto/aes-x86_64.mod.o > CC arch/x86/crypto/aesni-intel.mod.o > CC arch/x86/crypto/crc32-pclmul.mod.o > CC arch/x86/crypto/crc32c-intel.mod.o > (..) > > When reverting the entire pull with > > git diff 84d69848c97faab0c25aa2667b273404d2e2a64a > d4d24d2d0a7ea3b62efd7336bfc2344e29b36bc5 | patch -p1 > > everything is ok again. > > My system is a Debian Stretch. > gcc version 6.2.0 20161010 (Debian 6.2.0-6) > > ..config is attached - in the case I have an unusual one from your > perspective. > > Regards, > Oliver -- 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