tech-kern: Re: copyinstr() with a zero-length buffer

Subject: Re: copyinstr() with a zero-length buffer
To: Chuck Silvers <chuq@chuq.com>
From: Charles M. Hannum <root@ihack.net>
List: tech-kern
Date: 11/02/1999 10:40:22

Chuck Silvers <chuq@chuq.com> writes:

> here's a philosophical question for ya:  is it legal to call copyinstr()
> with maxlen == 0?

Yes.

> the sparc will panic if this happens, but the sample
> program in PR 7838 will cause sys_execve() to do just that.
> so which is wrong?

The SPARC code is definitely wrong.  There is no reason it should
*care* whether maxlen was 0.