powerpc: Fix a corner case in __div64_32

The code was incorrectly doing a division by 0 in the case where
the denominator was 0x100000000 and the divisor was 0xffffffff.
Thanks to Fred Liu of Motorola for pointing this out.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/powerpc/lib/div64.S b/arch/powerpc/lib/div64.S
index 3527569e9926..83d9832fd919 100644
--- a/arch/powerpc/lib/div64.S
+++ b/arch/powerpc/lib/div64.S
@@ -33,9 +33,10 @@ _GLOBAL(__div64_32)
         cntlzw  r0,r5           # we are shifting the dividend right
         li      r10,-1          # to make it < 2^32, and shifting
         srw     r10,r10,r0      # the divisor right the same amount,
-        add     r9,r4,r10       # rounding up (so the estimate cannot
+        addc    r9,r4,r10       # rounding up (so the estimate cannot
         andc    r11,r6,r10      # ever be too large, only too small)
         andc    r9,r9,r10
+        addze   r9,r9
         or      r11,r5,r11
         rotlw   r9,r9,r0
         rotlw   r11,r11,r0