Date: Tue, 22 Oct 1996 10:59:08 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: proff@suburbia.net (Julian Assange) Cc: imp@village.org, hackers@FreeBSD.org Subject: Re: libc string routines don't check for NULL pointers Message-ID: <199610221759.KAA08248@phaeton.artisoft.com> In-Reply-To: <199610221502.BAA23250@suburbia.net> from "Julian Assange" at Oct 23, 96 01:02:52 am
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> > str*cmp and friends should be hard asses about this and should give > > the programer a nice core file when this happens, subject to local > > security constraints. NULL pointer checking can slow down these > > routines, but I've never seen numbers to back up speed differences. > > > > Just my humble opinion from about 10 years of doing this stick. > > Others may disagree. > > No need to do this, just make sure the vm system never maps page 0. Actually, it should be noted that SVR4 will map an empty page 0 on first fault (hiding subsequent faults entilrely) as a backward compatability "trick" for bogus programs. It's actually possible to turn this "feature" off using an undocumented compile-time option. Only problem is, some of the bogus programs are system programs. SVR4 needs to be run through Purify. 8-(. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
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