From owner-freebsd-bugs  Sat Jan 11 06:41:33 1997
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Date: Thu, 11 Jan 1996 01:40:10 +0000 ()
From: David Nugent <davidn@unique.usn.blaze.net.au>
Reply-To: davidn@blaze.net.au
To: Philippe Charnier <charnier@xp11.frmug.org>
cc: FreeBSD-gnats-submit@freebsd.org,
        GNATS Management <gnats@freefall.freebsd.org>,
        freebsd-bugs@freefall.freebsd.org
Subject: Re: bin/2442: setusershell()/endusershell() missing
In-Reply-To: <199701110134.CAA28437@xp11.frmug.org>
Message-ID: <Pine.BSF.3.95.960111012722.438A-100000@labs.usn.blaze.net.au>
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On Sat, 11 Jan 1997, Philippe Charnier wrote:

>	The right way (TM) should be:
>		setusershell()
>		some getusershell()
>		endusershell()

In theory at least. :-)


> 	setusershell();
> 	while (sh = getusershell()) {
> 		if (!strcmp(name, sh))
>-			return (name);
>+			{ endusershell(); return (name); }
> 		/* allow just shell name, but use "real" path */
> 		if ((p = strrchr(sh, '/')) && strcmp(name, p + 1) == 0)
>-			return (sh);
>+			{ endusershell(); return (sh); }

The problem in some places patched is that 'sh' will point to
memory that has been free()'ed by the call to endusershell(). Not
all, but some.

Either this should be documented, and strdup() called prior
endusershell() is called and the strdup()ed copy should be
returned, or /usr/src/lib/libc/gen/getusershell.c should be made
to not to free that memory, but recycle it should setusershell()
be called again. I think the latter is a better solution, which
would allow this patch to work as is. However, libc needs to be
fixed first.

Regards,

David Nugent - Unique Computing Pty Ltd - Melbourne, Australia
Voice +61-3-9791-9547  Data/BBS +61-3-9792-3507  3:632/348@fidonet
davidn@freebsd.org davidn@blaze.net.au http://www.blaze.net.au/~davidn/