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Date: Thu, 25 Dec 1997 22:00:01 -0800 (PST)
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From: Tim Vanderhoek <ac199@hwcn.org>
Subject: Re: kern/2412
Reply-To: Tim Vanderhoek <ac199@hwcn.org>
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The following reply was made to PR kern/2412; it has been noted by GNATS.

From: Tim Vanderhoek <ac199@hwcn.org>
To: Bruce Evans <bde@zeta.org.au>
Cc: dima@tejblum.dnttm.rssi.ru, hoek@freebsd.org, h-nokubi@nmit.mt.nec.co.jp,
        gnats-submit@freebsd.org
Subject: Re: kern/2412
Date: Mon, 25 Nov 1996 23:49:38 -0500 (EST)

 On Fri, 26 Dec 1997, Bruce Evans wrote:
 
 > No one specific is responsible, but USER_LDT is obviously quite
 > broken without the option being visible.  fork(), exec() and exit()
 
 Okay, but I'm not about to enable untested code in machdep.c or
 vm_machdep.c, so I'll change the synopsis to reflect the problem,
 and add this message and one of Dima's to the audit-trail.
 
 I'll also note that the originator reports that the original
 problem ("wine does not run") can be worked-around by using a
 newer version of wine.
 
 > are broken.  fork()ing with an active user LDT at best leaves 2
 > processes sharing the LDT.  exec()ing with an active LDT leaks
 > memory and privilege.  exit()Ing with an active LDT leaks memory.
 > I guess wine doesn't change the user LDT often enough for the bugs
 > to do more than leak memory.
 > 
 > I'd like testing of misconfigured options to be fatal but can't see
 > a good way to implement it.  A bad way:
 > - in opt_global.h, define each option that doesn't belong in opt_global.h
 >   as an expression with a syntax error.
 > - redefine the expression in each opt_foo.h file (same as now, except
 >   for an #undef to prevent a warning).
 > - change each test of an option to use `#if' to ensure an error if the
 >   expression is not defined properly.
 > 
 > Bruce
 > 
 
 --
  tIM...HOEk
 OPTIMIZATION: the process of using many one-letter variables names
               hoping that the resultant code will run faster.