From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753239Ab1HHTdM (ORCPT ); Mon, 8 Aug 2011 15:33:12 -0400 Received: from mail.candelatech.com ([208.74.158.172]:33958 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752933Ab1HHTdK (ORCPT ); Mon, 8 Aug 2011 15:33:10 -0400 Message-ID: <4E4039F3.9010802@candelatech.com> Date: Mon, 08 Aug 2011 12:33:07 -0700 From: Ben Greear Organization: Candela Technologies User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100430 Fedora/3.0.4-2.fc11 Thunderbird/3.0.4 MIME-Version: 1.0 To: Randy Dunlap CC: gregkh@suse.de, linux-kernel Subject: Re: 3.0.1 compile error on Fedora 15 References: <4E402E5F.5010600@candelatech.com> <20110808115238.b19b293e.rdunlap@xenotime.net> <4E403121.8080402@candelatech.com> <20110808121104.5a233da4.rdunlap@xenotime.net> In-Reply-To: <20110808121104.5a233da4.rdunlap@xenotime.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/08/2011 12:11 PM, Randy Dunlap wrote: > On Mon, 08 Aug 2011 11:55:29 -0700 Ben Greear wrote: > >> On 08/08/2011 11:52 AM, Randy Dunlap wrote: >>> On Mon, 08 Aug 2011 11:43:43 -0700 Ben Greear wrote: >>> >>>> [greearb@t60-ben linux-3.0.p4s]$ make >>>> make -C /home/greearb/git/linux-3.0.dev.y O=/home/greearb/kernel/2.6/linux-3.0.p4s/. >>>> Using /home/greearb/git/linux-3.0.dev.y as source for kernel >>>> GEN /home/greearb/kernel/2.6/linux-3.0.p4s/Makefile >>>> CHK include/linux/version.h >>>> CHK include/generated/utsrelease.h >>>> CALL /home/greearb/git/linux-3.0.dev.y/scripts/checksyscalls.sh >>>> CHK include/generated/compile.h >>>> CC fs/binfmt_misc.o >>>> In file included from /home/greearb/git/linux-3.0.dev.y/arch/x86/include/asm/uaccess.h:570:0, >>>> from /home/greearb/git/linux-3.0.dev.y/include/linux/uaccess.h:5, >>>> from /home/greearb/git/linux-3.0.dev.y/include/linux/highmem.h:7, >>>> from /home/greearb/git/linux-3.0.dev.y/include/linux/pagemap.h:10, >>>> from /home/greearb/git/linux-3.0.dev.y/fs/binfmt_misc.c:26: >>>> /home/greearb/git/linux-3.0.dev.y/arch/x86/include/asm/uaccess_32.h: In function ‘parse_command.part.0’: >>>> /home/greearb/git/linux-3.0.dev.y/arch/x86/include/asm/uaccess_32.h:211:26: error: call to ‘copy_from_user_overflow’ declared with attribute error: >>>> copy_from_user() buffer size is not provably correct >>>> make[3]: *** [fs/binfmt_misc.o] Error 1 >>>> make[2]: *** [fs] Error 2 >>>> make[1]: *** [sub-make] Error 2 >>>> make: *** [all] Error 2 >>>> [greearb@t60-ben linux-3.0.p4s]$ >>>> >>>> >>>> The code in question is below. Is this missing an assignment to n >>>> in the else branch? >>>> >>>> static inline unsigned long __must_check copy_from_user(void *to, >>>> const void __user *from, >>>> unsigned long n) >>>> { >>>> int sz = __compiletime_object_size(to); >>>> >>>> if (likely(sz == -1 || sz>= n)) >>>> n = _copy_from_user(to, from, n); >>>> else >>>> copy_from_user_overflow(); >>>> >>>> return n; >>>> } >>> >>> >>> Do you have this kconfig option enabled? >>> CONFIG_DEBUG_STRICT_USER_COPY_CHECKS=y >>> >>> If so, you should get the error that you reported. >>> If not, then you need a patch like the one below (which has been posted >>> by other people several times -- might need to be added to -stable): >> >> I do have that enabled. I'm slightly confused by your response above: >> >> Do I need to disable the check AND apply the patch below, or just disable >> the check, or just apply the patch and leave the check enabled? > > Hm, I guess I'm confused also. The patch only applies to linux-next, > not to 3.0.x. > > The patch below is needed (in linux-next) to fix a build > error when CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is not enabled. > > When you do have CONFIG_DEBUG_STRICT_USER_COPY_CHECKS, the build error is > the correct result. AFAIK. So it looks to me like you should either > disable the kconfig option or fix the code in fs/binfmt_misc.c. > I would do the former -- depending on your use case. I can disable the check, but I hope someone fixes the real problem and sends the patch to stable. Seems a bit lame that we have compile errors in stable series... Thanks, Ben > > >> Thanks, >> Ben >> >>> >>> >>> --- >>> lib/Makefile | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> --- linux-next-20110728.orig/lib/Makefile >>> +++ linux-next-20110728/lib/Makefile >>> @@ -14,7 +14,7 @@ lib-y := ctype.o string.o vsprintf.o cmd >>> proportions.o prio_heap.o ratelimit.o show_mem.o \ >>> is_single_threaded.o plist.o decompress.o find_next_bit.o >>> >>> -lib-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o >>> +obj-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o >>> lib-$(CONFIG_MMU) += ioremap.o >>> lib-$(CONFIG_SMP) += cpumask.o >>> >> >> >> -- > > > --- > ~Randy > *** Remember to use Documentation/SubmitChecklist when testing your code *** > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Ben Greear Candela Technologies Inc http://www.candelatech.com