From owner-freebsd-hackers@FreeBSD.ORG Mon Aug 16 17:18:18 2010 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0EFB8106576E; Mon, 16 Aug 2010 17:18:15 +0000 (UTC) (envelope-from marius@alchemy.franken.de) Received: from alchemy.franken.de (alchemy.franken.de [194.94.249.214]) by mx1.freebsd.org (Postfix) with ESMTP id 7DC898FC18; Mon, 16 Aug 2010 17:18:14 +0000 (UTC) Received: from alchemy.franken.de (localhost [127.0.0.1]) by alchemy.franken.de (8.14.3/8.14.3/ALCHEMY.FRANKEN.DE) with ESMTP id o7GHICBF022457; Mon, 16 Aug 2010 19:18:12 +0200 (CEST) (envelope-from marius@alchemy.franken.de) Received: (from marius@localhost) by alchemy.franken.de (8.14.3/8.14.3/Submit) id o7GHIBJm022456; Mon, 16 Aug 2010 19:18:11 +0200 (CEST) (envelope-from marius) Date: Mon, 16 Aug 2010 19:18:11 +0200 From: Marius Strobl To: Kostik Belousov Message-ID: <20100816171811.GC904@alchemy.franken.de> References: <20100806050633.GK14016@felucia.tataz.chchile.org> <20100806090404.GI22295@deviant.kiev.zoral.com.ua> <20100806110807.GA68489@alchemy.franken.de> <20100806111131.GN22295@deviant.kiev.zoral.com.ua> <20100807135939.GA875@alchemy.franken.de> <20100807180904.GZ22295@deviant.kiev.zoral.com.ua> <20100807193722.GB875@alchemy.franken.de> <20100814143225.GA2396@deviant.kiev.zoral.com.ua> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100814143225.GA2396@deviant.kiev.zoral.com.ua> User-Agent: Mutt/1.4.2.3i Cc: kan@freebsd.org, FreeBSD Hackers , Jeremie Le Hen , nwhitehorn@freebsd.org Subject: Re: Avoiding sysctl at program startup using ELF aux vector (was: concurrent sysctl implementation) X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 Aug 2010 17:18:18 -0000 On Sat, Aug 14, 2010 at 05:32:25PM +0300, Kostik Belousov wrote: > On Sat, Aug 07, 2010 at 09:37:22PM +0200, Marius Strobl wrote: > > On Sat, Aug 07, 2010 at 09:09:04PM +0300, Kostik Belousov wrote: > > > On Sat, Aug 07, 2010 at 03:59:39PM +0200, Marius Strobl wrote: > > > > On Fri, Aug 06, 2010 at 02:11:31PM +0300, Kostik Belousov wrote: > > > > > On Fri, Aug 06, 2010 at 01:08:08PM +0200, Marius Strobl wrote: > > > > > > On Fri, Aug 06, 2010 at 12:04:04PM +0300, Kostik Belousov wrote: > > > > > > > On Fri, Aug 06, 2010 at 07:06:33AM +0200, Jeremie Le Hen wrote: > > > > > > > > Hi Kib, > > > > > > > > > > > > > > > > In-Reply-To: <20100629083901.GG13238@deviant.kiev.zoral.com.ua> > > > > > > > > On Tue, Jun 29, 2010 at 11:39:01AM +0300, Kostik Belousov wrote: > > > > > > > > > On Tue, Jun 29, 2010 at 10:26:39AM +0200, Marius Strobl wrote: > > > > > > > > > > On Mon, Jun 28, 2010 at 05:48:59PM +0300, Kostik Belousov wrote: > > > > > > > > > > > On Wed, Jun 23, 2010 at 11:09:59PM +0200, Jeremie Le Hen wrote: > > > > > > > > > > > > Hi Kostik, > > > > > > > > > > > > > > > > > > > > > > > > This patch seems to have faded out from memory. Is it possible to go > > > > > > > > > > > > forward and commit it? > > > > > > > > > > > I refreshed the patch. Hopefully, nobody will object, and I commit it > > > > > > > > > > > shortly. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > > > > Regards. > > > > > > > > > > > > > > > > > > > > > > > > On Sat, Jul 25, 2009 at 12:29:16AM +0300, Kostik Belousov wrote: > > > > > > > > > > > > > Below is the prototype that seems to work for me both with patched and > > > > > > > > > > > > > old rtld on i386. Patch also contains bits for amd64 that I did not > > > > > > > > > > > > > tested yet. All other arches are not buildable for now. > > > > > > > > > > > > > > > > > > > > > > > > > > Patch completely eliminates sysctl syscalls from the rtld and libc > > > > > > > > > > > > > startup. Without the patch, a single run of /bin/ls did 6 sysctls, > > > > > > > > > > > > > with the patch, no sysctls is queried at all. > > > > > > > > > > > > > > > > > > > > > > > > Comparing with the originally posted patch, I added support for all > > > > > > > > > > > architectures, tested amd64 and ia32 on amd64, and converted getpagesizes(3) > > > > > > > > > > > that added two more startup sysctls. > > > > > > > > > > > > > > > > > > > > > > Would be nice to get a testing for at least some !x86 architectures > > > > > > > > > > > before the commit, I added some people who helped me in past, to the Cc:. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Doesn't look good on sparc64: > > > > > > > > > > <...> > > > > > > > > > > NFS ROOT: 192.168.1.40:/usr/data/nfsroot/sparc64 > > > > > > > > > > dc1: link state changed to UP > > > > > > > > > > pid 24 (ifconfig), uid 0: exited on signal 11 > > > > > > > > > > Segmentation fault > > > > > > > > > > Interface IP-Address Broadcast > > > > > > > > > > pid 29 (rcorder), uid 0: exited on signal 11 > > > > > > > > > > Segmentation fault > > > > > > > > > > pid 30 (grep), uid 0: exited on signal 11 > > > > > > > > > > Segmentation fault > > > > > > > > > > pid 31 (rcorder), uid 0: exited on signal 11 > > > > > > > > > > Segmentation fault > > > > > > > > > > > > > > > > > > > > pid 32 (date), uid 0: exited on signal 11 > > > > > > > > > > Segmentation fault > > > > > > > > > > Jun 29 12:20:50 getty[36]: open /dev/ttyv3: No such file or directory > > > > > > > > > > <...> > > > > > > > > > > > > > > > > > > > > Unfortunately, I currently lack the time to debug this. > > > > > > > > > > > > > > > > > > Thank you. > > > > > > > > > > > > > > > > Did yu have time to look at this problem? It would be nice to have this > > > > > > > > in the tree. > > > > > > > > > > > > > > I cannot move forward without the help from somebody having access to > > > > > > > sparc64 system where the problem is reproducable. > > > > > > > > > > > > Do you have a debug version of the patch which outputs the necessary > > > > > > information? > > > > > > > > > > I would suggest to build rtld and libc with debugging symbols and > > > > > get full backtrace from the faults. > > > > > > > > v100# gdb /sbin/ifconfig ifconfig.core > > > > GNU gdb 6.1.1 [FreeBSD] > > > > Copyright 2004 Free Software Foundation, Inc. > > > > GDB is free software, covered by the GNU General Public License, and you are > > > > welcome to change it and/or distribute copies of it under certain conditions. > > > > Type "show copying" to see the conditions. > > > > There is absolutely no warranty for GDB. Type "show warranty" for details. > > > > This GDB was configured as "sparc64-marcel-freebsd"... > > > > Core was generated by `ifconfig'. > > > > Program terminated with signal 11, Segmentation fault. > > > > Reading symbols from /lib/libbsdxml.so.4...done. > > > > Loaded symbols for /lib/libbsdxml.so.4 > > > > Reading symbols from /lib/libjail.so.1...done. > > > > Loaded symbols for /lib/libjail.so.1 > > > > Reading symbols from /lib/libsbuf.so.5...done. > > > > Loaded symbols for /lib/libsbuf.so.5 > > > > Reading symbols from /lib/libipx.so.5...done. > > > > Loaded symbols for /lib/libipx.so.5 > > > > Reading symbols from /lib/libc.so.7...done. > > > > Loaded symbols for /lib/libc.so.7 > > > > Reading symbols from /libexec/ld-elf.so.1...done. > > > > Loaded symbols for /libexec/ld-elf.so.1 > > > > #0 0x000000004089ebdc in getpagesizes (pagesize=0x7fdffffe2f8, nelem=1) > > > > at /usr/home/marius/co/head/src/lib/libc/gen/getpagesizes.c:75 > > > > 75 while (nops > 0 && ps[nops - 1] == 0) > > > > (gdb) bt > > > > #0 0x000000004089ebdc in getpagesizes (pagesize=0x7fdffffe2f8, nelem=1) > > > > at /usr/home/marius/co/head/src/lib/libc/gen/getpagesizes.c:75 > > > > #1 0x00000000407f4314 in malloc_init () > > > > at /usr/home/marius/co/head/src/lib/libc/stdlib/malloc.c:5418 > > > > #2 0x00000000407f67d8 in malloc (size=32) > > > > at /usr/home/marius/co/head/src/lib/libc/stdlib/malloc.c:5932 > > > > #3 0x00000000001069ac in clone_setdefcallback (ifprefix=0x11b8a8 "wlan", > > > > p=0x10a1a0 ) > > > > at /usr/home/marius/co/head/src/sbin/ifconfig/ifclone.c:106 > > > > #4 0x0000000000119864 in __do_global_ctors_aux () > > > > #5 0x000000000010243c in _init () > > > > #6 0x0000000000102508 in _start () > > > > #7 0x000000004022719c in .rtld_start () > > > > at /usr/home/marius/co/head/src/libexec/rtld-elf/sparc64/rtld_start.S:59 > > > > #8 0x000000004022719c in .rtld_start () > > > > at /usr/home/marius/co/head/src/libexec/rtld-elf/sparc64/rtld_start.S:59 > > > > Previous frame identical to this frame (corrupt stack?) > > > > > > > > All faults I've looked at died the same why. > > > Thank you. I think I found the reason, which was an unitialized > > > variable. I also fixed a sillyness with osrelver. > > > > > > In the patched tree, there is tools/test/auxinfo that could be used to > > > quick-check the system. > > > > > > Updated patch is available at > > > http://people.freebsd.org/~kib/misc/rtld_auxinfo.1.patch > > > > I can confirm that this versions works on sparc64. > After the discussion with Alexander, I made the change to allow libc to > access aux vectors, instead of providing rtld interface to fetch values. > > I decided to keep the single function that fetch the values, because it > is convenient place to do digesting of the vector. > > http://people.freebsd.org/~kib/misc/rtld_auxinfo.2.patch This version also works on sparc64 (I've verified that no sysctls are invoked during startup). Marius