Re: [MIPS] Fix handling of trap and breakpoint instructions

[David Daney <ddaney@avtrex.com>]

Atsushi Nemoto wrote:
> > Author: Ralf Baechle <ralf@linux-mips.org> Sun Apr 20 16:28:54 2008 +0100
> > Commit: 5881bb0de64887a60f7f49922cf73a3b4d40fc01
> > Gitweb: http://www.linux-mips.org/g/linux/5881bb0d
> > Branch: master
> You must drop left shift of this line too.
>
>                 if (bcode == (BRK_DIVZERO << 10))
Note that there has been some confusion about break codes in gas over 
the years.  Ancient versions (I am not sure which) generated different 
break codes than recent versions.
Before changing it make sure that you don't break existing user space code.

One problem (fixed around 2.4.25 or so) was the integer division by zero 
in user space would result in SIGTRAP instead of SIGFPE.   If you change 
the break code handling you should verify that you don't break this.
David Daney