powerpc: Fix a corner case in __div64_32

Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

kernel os linux

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>

Paul Mackerras 20 years ago 344480b9 a4bcc95a

+2 -1

1 changed file

expand all

arch

powerpc

lib

div64.S

+2 -1

arch/powerpc/lib/div64.S

··· 33 33 cntlzw r0,r5 # we are shifting the dividend right 34 34 li r10,-1 # to make it < 2^32, and shifting 35 35 srw r10,r10,r0 # the divisor right the same amount, 36 - add r9,r4,r10 # rounding up (so the estimate cannot 36 + addc r9,r4,r10 # rounding up (so the estimate cannot 37 37 andc r11,r6,r10 # ever be too large, only too small) 38 38 andc r9,r9,r10 39 + addze r9,r9 39 40 or r11,r5,r11 40 41 rotlw r9,r9,r0 41 42 rotlw r11,r11,r0