On 03/01/13 20:16, Stephen Boyd wrote:

On 03/01/13 19:42, Stephen Boyd wrote:

quoted

On 03/01/13 19:00, Randy Dunlap wrote:

quoted

On 03/01/13 15:51, akpm@linux-foundation.org wrote:

quoted

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.

quoted

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