Re: link error : 2.6.21-rc6-mm1 for s390

[David Miller <davem@davemloft.net>]

From: Andrew Morton <akpm@linux-foundation.org>
Date: Tue, 10 Apr 2007 18:47:38 -0700

> attribute(weak) would give a nicer result?
> 
> We'd also need to remove s390's EXPORT_SYMBOL(__div64_32), so s390 ends up
> using lib/div64.c's EXPORT_SYMBOL().

Ok, here is the version of the fix I'll use for now:

commit c3abb3b8d41814ce4691cc4cc3998b0f5242c8d0
Author: David S. Miller <davem@sunset.davemloft.net>
Date:   Tue Apr 10 22:10:39 2007 -0700

    [S390]: Fix build on 31-bit.
    
    Allow s390 to properly override the generic
    __div64_32() implementation by:
    
    1) Using obj-y for div64.o in s390's makefile instead
       of lib-y
    
    2) Adding the weak attribute to the generic implementation.
    
    Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/arch/s390/lib/Makefile b/arch/s390/lib/Makefile
index 7a44fed..59aea65 100644
--- a/arch/s390/lib/Makefile
+++ b/arch/s390/lib/Makefile
@@ -5,6 +5,6 @@
 EXTRA_AFLAGS := -traditional
 
 lib-y += delay.o string.o uaccess_std.o uaccess_pt.o qrnnd.o
-lib-$(CONFIG_32BIT) += div64.o
+obj-$(CONFIG_32BIT) += div64.o
 lib-$(CONFIG_64BIT) += uaccess_mvcos.o
 lib-$(CONFIG_SMP) += spinlock.o
diff --git a/arch/s390/lib/div64.c b/arch/s390/lib/div64.c
index 0481f34..a5f8300 100644
--- a/arch/s390/lib/div64.c
+++ b/arch/s390/lib/div64.c
@@ -147,5 +147,3 @@ uint32_t __div64_32(uint64_t *n, uint32_t base)
 }
 
 #endif /* MARCH_G5 */
-
-EXPORT_SYMBOL(__div64_32);
diff --git a/lib/div64.c b/lib/div64.c
index 74f0c8c..b71cf93 100644
--- a/lib/div64.c
+++ b/lib/div64.c
@@ -23,7 +23,7 @@
 /* Not needed on 64bit architectures */
 #if BITS_PER_LONG == 32
 
-uint32_t __div64_32(uint64_t *n, uint32_t base)
+uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base)
 {
 	uint64_t rem = *n;
 	uint64_t b = base;