Date: Thu, 20 Aug 1998 15:53:39 -0700 (PDT) From: Archie Cobbs <archie@whistle.com> To: imp@village.org (Warner Losh) Cc: eivind@yes.no, hackers@FreeBSD.ORG Subject: Re: Realloc fix for review Message-ID: <199808202253.PAA10143@bubba.whistle.com> In-Reply-To: <199808202221.QAA25040@harmony.village.org> from Warner Losh at "Aug 20, 98 04:21:51 pm"
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Warner Losh writes:
> In message <199808202155.OAA09132@bubba.whistle.com> Archie Cobbs writes:
> : A better thing would be to replace all instances of "a = realloc(a, size)"
> : with <insert bug-free code here>, depending on what the program is trying
> : to do in that particular instance.
>
> If you actually look at the code, you'll find that most of the code
> that does this realloc, does check to see if a is NULL. The only bug
> in most of the code that I've seen is that it doesn't free a in the
> failure case. That's why I invented frealloc.
>
> That is, the code generally deals with failre nearly correctly. for
> example, in getcap we have:
> record = realloc(record, newsize);
> if (record == NULL) {
> errno = ENOMEM;
> if (myfd)
> (void)close(fd);
> return (-2);
> }
>
> which clearly does the right thing, except for freeing the old
> record.... There are other cases where this is the case.
Well, the proof is in the pudding, er source code. In any case,
a system-wide scan of this sort of bug would be a good thing IMHO.
-Archie
___________________________________________________________________________
Archie Cobbs * Whistle Communications, Inc. * http://www.whistle.com
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