lkml.org 
[lkml]   [2020]   [Aug]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: Re:Re: [PATCH] powerpc: Fix a bug in div64 32 if divisor is zero
Date
From: Guohua Zhong
> Sent: 24 August 2020 14:26
>
> >> >In generic version in lib/math/div64.c, there is no checking of 'base'
> >> >either.
> >> >Do we really want to add this check in the powerpc version only ?
> >>
> >> >The only user of __div64_32() is do_div() in
> >> >include/asm-generic/div64.h. Wouldn't it be better to do the check there ?
> >>
> >> >Christophe
> >>
> >> Yet, I have noticed that there is no checking of 'base' in these functions.
> >> But I am not sure how to check is better.As we know that the result is
> >> undefined when divisor is zero. It maybe good to print error and dump stack.

I thought that the onus was put on the caller to avoid divide by zero.

On x86 divide by zero causes an exception which (I'm pretty sure)
leads to a oops/panic.

David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
\
 
 \ /
  Last update: 2020-08-24 17:08    [W:0.068 / U:0.064 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site