Messages in this thread | | | Date | Fri, 01 Mar 2013 21:22:35 -0800 | From | Randy Dunlap <> | Subject | Re: mmotm 2013-03-01-15-50 uploaded (strict user copy) |
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On 03/01/13 20:16, Stephen Boyd wrote: > On 03/01/13 19:42, Stephen Boyd wrote: >> On 03/01/13 19:00, Randy Dunlap wrote: >>> On 03/01/13 15:51, akpm@linux-foundation.org wrote: >>>> The mm-of-the-moment snapshot 2013-03-01-15-50 has been uploaded to >>>> >>>> http://www.ozlabs.org/~akpm/mmotm/ >>>> >>> on i386: >>> >>> ERROR: "copy_from_user_overflow" [fs/binfmt_misc.ko] undefined! >>> >>> which I don't understand. >>> lib/usercopy.o is built and building binfmt_misc.c says: >>> >>> CC [M] fs/binfmt_misc.o >>> In file included from arch/x86/include/asm/uaccess.h:537:0, >>> from include/linux/uaccess.h:5, >>> from include/linux/highmem.h:8, >>> from include/linux/pagemap.h:10, >>> from fs/binfmt_misc.c:27: >>> arch/x86/include/asm/uaccess_32.h: In function 'parse_command.part.1': >>> arch/x86/include/asm/uaccess_32.h:211:26: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct [enabled by default] >> Hm.. That's because it's part of lib and not obj, right?
Yes, this fixes the build error.
>> diff --git a/lib/Makefile b/lib/Makefile >> index 59fabd0..4c55104 100644 >> --- a/lib/Makefile >> +++ b/lib/Makefile >> @@ -15,7 +15,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ >> is_single_threaded.o plist.o decompress.o kobject_uevent.o \ >> earlycpio.o percpu-refcount.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 >> >> > > I'm a little confused though because it is lib-y on x86 before my patch.
binfmt_misc is built as a loadable module in my config. It must be the only user of copy_from_user_overflow() in this config. I guess that it would also fail prior to your patch, but I haven't tested it. Anyway, your patch above is correct and needed.
thanks, -- ~Randy
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