Re: toolchain/42181: pwcache compat broken in OS X

[Frank Zerangue <frank.zerangue%gmail.com@localhost>]

The following reply was made to PR toolchain/42181; it has been noted by GNATS.

From: Frank Zerangue <frank.zerangue%gmail.com@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: toolchain/42181: pwcache compat broken in OS X
Date: Wed, 14 Oct 2009 08:27:59 -0500

 Please see toolchain/42014. I have a patch that fixes this.
 
 Frank
 
 On Oct 14, 2009, at 4:00 AM, jmmv%NetBSD.org@localhost wrote:
 
 >> Number:         42181
 >> Category:       toolchain
 >> Synopsis:       pwcache compat broken in OS X
 >> Confidential:   no
 >> Severity:       serious
 >> Priority:       medium
 >> Responsible:    toolchain-manager
 >> State:          open
 >> Class:          sw-bug
 >> Submitter-Id:   net
 >> Arrival-Date:   Wed Oct 14 09:00:00 +0000 2009
 >> Originator:     Julio Merino
 >> Release:        NetBSD-current sources as of 2009/10/14
 >> Organization:
 >      
 >> Environment:
 >      
 >      
 > System: Darwin calypso 9.8.0 Darwin Kernel Version 9.8.0: Wed Jul 15  
 > 16:55:01 PDT 2009; root:xnu-1228.15.4~1/RELEASE_I386 i386
 >        Mac OS X Leopard 10.5.8.
 > Architecture: i386
 > Machine: i386
 >> Description:
 >      Cross-compilation of NetBSD on a Mac OS X Leopard host fails because
 >      mtree does not correctly handle user and group name.  mtree is  
 > messing
 >      up the NetBSD-specific user/group databases with the host ones.
 >
 >      As an example, when mtree is run to populate destdir, the METALOG  
 > ends
 >      up containing an entry like the following:
 >
 >          ./var/db/postfix type=dir uid=12 gname=everyone mode=0755
 >
 >      uid should be postfix and gname should be postfix.  However, these  
 > have
 >      been "corrupted" and point to 12 and everyone.  uid is 12 because 12
 >      does not have any valid name in the local /etc/passwd.  gname is
 >      everyone because /etc/group defines 12 as such.
 >
 >      I don't know when this started happening.  I seem to recall that I  
 > did
 >      previous builds on such a host before without problems, but I'm not
 >      sure.
 >
 >      DIAGNOSIS
 >
 >      Here comes my diagnosis of the problem, which may not be completely
 >      correct.
 >
 >      OS X has native user_to_uid and group_to_gid functions, but lacks
 >      pwcache_groupdb and pwcache_userdb.  When we build pwcache.c from
 >      tools/compat, we detect this situation.
 >
 >      The problem is that we only do a "partial replacement" of the native
 >      pwcache.  We provide our own pwcache_groupdb/userdb functions, but  
 > the
 >      original user_to_uid and group_to_gid functions remain in place.
 >
 >      Later on, mtree is executed with -N to specify an alternative passwd
 >      database, and it calls our own pwcache_* functions to internally
 >      switch to the alternative database.  Unfortunately, when the database
 >      is queried later on through user_to_uid and group_to_gid functions,  
 > we
 >      use the native functions which bypass our replacement.
 >
 >      I assume this is not working correctly because __weak_alias is not
 >      defined in OS X, and thus the dynamic replacement of all the  
 > functions
 >      with our compat ones is not working.
 >> How-To-Repeat:
 >      Cross-compile NetBSD-current on a Mac OS X Leopard host.
 >> Fix:
 >      Don't know what the best way to resolve this is.
 >
 >> Unformatted:
 >      
 >