Date: Wed, 13 Aug 2008 17:10:59 +0300 From: Kostik Belousov <kostikbel@gmail.com> To: Alexander Leidinger <Alexander@leidinger.net> Cc: Nate Eldredge <neldredge@math.ucsd.edu>, freebsd-hackers@freebsd.org Subject: Re: Debugging reboot with Linux emulation Message-ID: <20080813141059.GH1803@deviant.kiev.zoral.com.ua> In-Reply-To: <20080813160353.55171pui9o2wvm4g@webmail.leidinger.net> References: <Pine.GSO.4.64.0808122344020.11980@zeno.ucsd.edu> <20080813132822.18394zk66kfg0xcs@webmail.leidinger.net> <20080813115413.GF1803@deviant.kiev.zoral.com.ua> <20080813160353.55171pui9o2wvm4g@webmail.leidinger.net>
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--pfTAc8Cvt8L6I27a Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Aug 13, 2008 at 04:03:53PM +0200, Alexander Leidinger wrote: > Quoting "Kostik Belousov" <kostikbel@gmail.com> (from Wed, 13 Aug 2008 = =20 > 14:54:13 +0300): >=20 > >On Wed, Aug 13, 2008 at 01:28:22PM +0200, Alexander Leidinger wrote: > >>Quoting "Nate Eldredge" <neldredge@math.ucsd.edu> (from Tue, 12 Aug > >>2008 23:52:35 -0700 (PDT)): > >> > >>>Hi folks, > >>> > >>>I recently tried to run a Linux binary of Maple (commercial math > >>>software) on my FreeBSD 7.0-RELEASE/amd64 box, and the machine > >>>rebooted. I tried it again while watching the console, and no panic > >>>message appeared to be produced. Does anyone have any ideas on how > >>>to debug problems of this nature? I realize I may not be able to > >>>get Maple to work, but in any case the system should not die like > >>>this, so I can at least try to fix that bug. > >>> > >>>Incidentally, is it possible to run kdb with a USB keyboard? > >>>Hitting Ctrl-Alt-Esc gives me the kdb prompt, but I can't type, so I > >>>can do nothing except hit the power button. I do have > >>>hint.atkbd.0.flags=3D"0x1" in /boot/device.hints. Unfortunately I > >>>don't have a PS/2 keyboard on hand, though I can try and get a hold > >>>of one if all else fails. > >> > >>A guess out of my cristallball: > >>That's one of the cases which happen if you run a linux program > >>without branding it as a linux program first. People tend to think it > >>is not needed, but in some rare circumstances it just causes what you > >>see, a reboot. So go and identify all binaries (IMPORTANT: but not the > >>libraries!), e.g. with the file(1), and use "brandelf -t Linux" on > >>those programs. > > > >That would be an enormous local hole, assuming an native FreeBSD binary > >may cause system crash. I actually doubt that non-branded elf binary > >ever start, due to unsatisfied dynamic dependencies. >=20 > You see this behavior only for static binaries. In the non-branded =20 > case the image activator takes the FreeBSD image and unfortunately =20 > there's a common syscall in linux which matches the syscall number in =20 > FreeBSD which causes the reboot (IIRC reboot syscall, do we have =20 > something like this?). It's not a system crash (kernel panic), it's a =20 > real reboot. AFAIR this also only works if you run the program as =20 > root. So... Then, the issue of mixing our reboot(2)/linux fcntl(2) is irrelevant. The original reporter said that system "just rebooted", and I believe that filesystems where not synced and not unmounted properly. Our reboot(2) does not have flag combination that could cause such behaviour, I think. Also, I doubt that the program being run is statically linked or run by root. Confirmation ? Overall, this looks like a nasty bug, hopefully in the linuxolator. --pfTAc8Cvt8L6I27a Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) iEYEARECAAYFAkii63IACgkQC3+MBN1Mb4gceQCg1OCdT797XPj0qmboH5/NPz/c dxEAoKqwgoCV8Zry6TNWjRhs/tz3Ev/Q =Jjrq -----END PGP SIGNATURE----- --pfTAc8Cvt8L6I27a--
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