On Fri, Jul 29, 2011 at 5:13 PM, Randy Dunlap wrote: > On Fri, 29 Jul 2011 13:07:16 +0200 Sedat Dilek wrote: > >> On Fri, Jul 29, 2011 at 11:45 AM, Sedat Dilek >> wrote: >> > On Fri, Jul 29, 2011 at 11:02 AM, Sedat Dilek >> > wrote: >> >> On Fri, Jul 29, 2011 at 7:09 AM, Randy Dunlap wrote: >> >>> On Fri, 29 Jul 2011 03:34:26 +0200 Sedat Dilek wrote: >> >>> >> >>>> On Fri, Jul 29, 2011 at 1:01 AM, Randy Dunlap wrote: >> >>>> > On Thu, 28 Jul 2011 16:05:31 +0200 Sedat Dilek wrote: >> >>>> > >> >>>> >> Hi, >> >>>> >> >> >>>> >> just see this build-break on the last mile: >> >>>> >> >> >>>> >> [...] >> >>>> >>   OBJCOPY arch/x86/boot/compressed/vmlinux.bin >> >>>> >>   HOSTCC  arch/x86/boot/compressed/relocs >> >>>> >>   HOSTCC  arch/x86/boot/compressed/mkpiggy >> >>>> >> /mnt/sdb3/linux-kernel/linux-3.0/debian/build/source_i386_none/arch/x86/boot/compressed/relocs.c: >> >>>> >> In function 'print_absolute_symbols': >> >>>> >> /mnt/sdb3/linux-kernel/linux-3.0/debian/build/source_i386_none/arch/x86/boot/compressed/relocs.c:405:14: >> >>>> >> warning: variable 'sh_symtab' set but not used >> >>>> >> [-Wunused-but-set-variable] >> >>>> >> ERROR: "copy_from_user_overflow" [fs/binfmt_misc.ko] undefined! >> >>>> >> make[5]: *** [__modpost] Error 1 >> >>>> >> make[4]: *** [modules] Error 2 >> >>>> >> make[4]: *** Waiting for unfinished jobs.... >> >>>> >>   RELOCS  arch/x86/boot/compressed/vmlinux.relocs >> >>>> >>   GZIP    arch/x86/boot/compressed/vmlinux.bin.gz >> >>>> >>   MKPIGGY arch/x86/boot/compressed/piggy.S >> >>>> >>   AS      arch/x86/boot/compressed/piggy.o >> >>>> >>   LD      arch/x86/boot/compressed/vmlinux >> >>>> >>   ZOFFSET arch/x86/boot/zoffset.h >> >>>> >>   OBJCOPY arch/x86/boot/vmlinux.bin >> >>>> >>   AS      arch/x86/boot/header.o >> >>>> >>   LD      arch/x86/boot/setup.elf >> >>>> >>   OBJCOPY arch/x86/boot/setup.bin >> >>>> >>   BUILD   arch/x86/boot/bzImage >> >>>> >> Setup is 15596 bytes (padded to 15872 bytes). >> >>>> >> System is 2471 kB >> >>>> >> CRC eb598167 >> >>>> >> Kernel: arch/x86/boot/bzImage is ready  (#1) >> >>>> >> make[3]: *** [sub-make] Error 2 >> >>>> >> make[2]: *** [all] Error 2 >> >>>> >> >> >>>> >> I have these binfmt kernel-config options set: >> >>>> >> >> >>>> >> CONFIG_BINFMT_ELF=y >> >>>> >> # CONFIG_BINFMT_AOUT is not set >> >>>> >> CONFIG_BINFMT_MISC=m >> >>>> > >> >>>> > How does someone turn off this error message? >> >>>> > >> >>>> > I have: >> >>>> > # CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is not set >> >>>> > # CONFIG_STRICT_DEVMEM is not set >> >>>> > >> >>>> > and I still cannot get this error to go away (on x86_64). >> >>>> > >> >>>> > >> >>>> > --- >> >>>> > ~Randy >> >>>> > *** Remember to use Documentation/SubmitChecklist when testing your code *** >> >>>> > >> >>>> >> >>>> Can you say with which linux-next version you saw this first? >> >>>> My last version was next-20110722 (which was OK). >> >>> >> >>> It looks like 2011-0727 has lots of these errors in my randconfig builds, >> >>> but I can't say that they are all incorrect, so it's not very conclusive. >> >>> >> >>> --- >> >>> ~Randy >> >>> *** Remember to use Documentation/SubmitChecklist when testing your code *** >> >>> >> >> >> >> I can confirm next-20110726 is fine. >> >> >> >> # egrep 'BINFMT|DEBUG_STRICT_USER_COPY_CHECKS|STRICT_DEVMEM' >> >> /boot/config-3.0.0-next20110726.3-686-small >> >> CONFIG_BINFMT_ELF=y >> >> CONFIG_BINFMT_AOUT=m >> >> CONFIG_BINFMT_MISC=m >> >> CONFIG_STRICT_DEVMEM=y >> >> # CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is not set >> >> >> >> So, the binfmt_misc culprit was introduced between next-20110726 >> >> (good) and next-20110727 (bad). >> >> I'll try to look into the diff, but can't promise. >> >> >> >> - Sedat - >> >> >> > >> > [ CCing all people from 0416 patch ] >> > >> > OK, here a quick review and looking for suspicious commits: >> > >> > $ git format-patch next-20110726..next-20110727 >> > >> > 487 patches in total. >> > >> > $ grep copy_from_user_overflow -nr *.patch >> > >> > 0389-x86_64-allmodconfig.patch >> > 0414-Enabling-DEBUG_STRICT_USER_COPY_CHECKS-causes-the-fo.patch >> > 0415-Strict-user-copy-checks-are-only-really-supported-on.patch >> > 0416-The-help-text-for-this-config-is-duplicated-across-t.patch >> > >> > 0416 has thrown out... >> > >> > -void copy_from_user_overflow(void) >> > -{ >> > -       WARN(1, "Buffer overflow detected!\n"); >> > -} >> > -EXPORT_SYMBOL(copy_from_user_overflow); >> > >> > ...and consilidated that in... >> > >> > --- /dev/null >> > +++ b/lib/usercopy.c >> > @@ -0,0 +1,8 @@ >> > +#include >> > +#include >> > + >> > +void copy_from_user_overflow(void) >> > +{ >> > +       WARN(1, "Buffer overflow detected!\n"); >> > +} >> > +EXPORT_SYMBOL(copy_from_user_overflow); >> > >> > ...BUT builds usercopy.o only on >> > CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS... >> > >> > -- a/lib/Makefile >> > +++ b/lib/Makefile >> > @@ -14,6 +14,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ >> >         proportions.o prio_heap.o ratelimit.o show_mem.o \ >> >         is_single_threaded.o plist.o decompress.o find_next_bit.o >> > >> > +lib-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o >> >  lib-$(CONFIG_MMU) += ioremap.o >> >  lib-$(CONFIG_SMP) += cpumask.o >> > >> > So, I can rebuild next-201107{27,28} with >> > CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS=y and look again if the >> > build-breakage in binfmt_misc is gone. >> > >> > Any comments from x86 folk? >> > >> > - Sedat - >> > >> >> I was able to compile next-20110728 by reverting: >> >> commit ab3b49d018924085e5d949c1af53fae0da9a8d94 >> "The help text for this config is duplicated across the x86, parisc, >> and s390 Kconfig.debug files." >> >> The revert-patch is attached, also my kernel-config. >> >> Randy, can you test with it for x86_64, please? >> Thanks in advance. > > Yes, that works for me.  Thanks for your work on this problem. > > --- > ~Randy > *** Remember to use Documentation/SubmitChecklist when testing your code *** > Cool, you tested so fast, thanks. While watching DebConf11 live-stream, I played a bit with trying to fix the problem. I added back partially copy_from_user_overflow() back to arch/x86/lib/usercopy.c, so both x86_32 and x86_64 benefit from the change (initially copy_from_user_overflow() was in arch/x86/lib/usercopy_{32,64}). The attached patch works! I am still not understanding why there are several usercopy.c files below arch/ dir. The one "remained" in x86 includes only copy_from_user_nmi() and could IMHO be renamed to usercopy_nmi.c with adaptation in arch/x86/lib/Makefile. x86 folks? - Sedat - $ find ./ -name usercopy.c ./lib/usercopy.c ./arch/mn10300/lib/usercopy.c ./arch/x86/lib/usercopy.c ./arch/cris/arch-v10/lib/usercopy.c ./arch/cris/arch-v32/lib/usercopy.c ./arch/m32r/lib/usercopy.c