Date: Thu, 30 Sep 2004 08:46:45 -0400 From: Anish Mistry <mistry.7@osu.edu> To: John Baldwin <jhb@freebsd.org> Cc: Poul-Henning Kamp <phk@phk.freebsd.dk> Subject: Re: RELENG_5 panic: mtx_lock() with ACPI Message-ID: <200409300846.55452.mistry.7@osu.edu> In-Reply-To: <200409232136.54285.mistry.7@osu.edu> References: <200409201501.48755.mistry.7@osu.edu> <200409221518.00328.jhb@FreeBSD.org> <200409232136.54285.mistry.7@osu.edu>
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--nextPart1549572.oiUUMmHUBb Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Thursday 23 September 2004 09:36 pm, Anish Mistry wrote: > On Wednesday 22 September 2004 03:18 pm, John Baldwin wrote: > > On Tuesday 21 September 2004 06:14 pm, Anish Mistry wrote: > > > On Tuesday 21 September 2004 03:26 pm, you wrote: > > > > On Tuesday 21 September 2004 03:05 pm, Anish Mistry wrote: > > > > > On Monday 20 September 2004 04:00 pm, you wrote: > > > > > > Anish Mistry wrote: > > > > > > > On Monday 20 September 2004 03:35 pm, you wrote: > > > > > > >>Anish Mistry wrote: > > > > > > >>>On Monday 20 September 2004 03:01 pm, Anish Mistry wrote: > > > > > > >>>>I'm getting the following panic on boot only with ACPI > > > > > > >>>> enabled. On a verbose boot right after: start_init: trying > > > > > > >>>> /sbin/init panic: mtx_lock() of spin mutex(null) @ > > > > > > >>>> /usr/src/sys/tty/tty.c:2809 Can't seem to get a dump even = if > > > > > > >>>> dumpdev is set at the loader prompt. > > > > > > >>>> > > > > > > >>>>Verbose boot without ACPI enabled and ASL attached. > > > > > > >>> > > > > > > >>>Attachments got stripped. > > > > > > >>>http://am-productions.biz/debug/BIGGUY-dmesg.txt.gz > > > > > > >>>http://am-productions.biz/debug/bigguy.asl.gz > > > > > > >> > > > > > > >>Can you send a backtrace ("tr" from ddb)? > > > > > > > > > > > > > > It doesn't break to the ddb prompt. > > > > > > > > > > > > Can you enable options DDB? If ddb is enabled, all panics shou= ld > > > > > > break to the debugger. > > > > > > > > > > Ok, I removed WITNESS and INVARIANTS from my kernel config, and n= ow > > > > > it's dropping to a db> prompt. > > > > > > > > You want to keep INVARIANTS as it find problems sooner and in easier > > > > to debug locations. Can you turn INVARIANTS back on at least and > > > > then get a trace? > > > > > > > > > BTW, is there a way to set the dump device at the loader that > > > > > works. > > > > > > > > Not that I'm aware of. > > > > > > With INVARIANTS enabled: > > > panic: mtx_lock() of spin mutex(null) @ /usr/src/sys/tty/tty.c:2809 > > > KDB: enter: panic > > > [thread 100063] > > > Stopped at kdb_enter+0x2c: leave > > > kdb_enter(c06288da,100,af9,c062c3f3,0) at kdb_enter+0x2c > > > _mtx_lock_flags(c0680f80,0,c062c3f4,af9,d0c3bb60) at > > > _mtx_lock_flags+0x82 sysctl_kern_ttys(c065a160,0,0,d0c3bc04,c065a160) > > > at sysctl_kern_ttys+0x22 sysctl_root(2,d0c3bc04,c13f04b0,1,0) at > > > sysctl_root+0x83 > > > userland_sysctl(c13f04b0,d0c3bc80,2,0,bfbfe4ac,0,0,0,d0c3bc7c,c067bdc= 0, > > >0, c0 62929c,4e7) at userland_sysctl+0xd8 > > > __sysctl(c13f04b0,d0c3db14,6,0,292) at __sysctl+0x78 > > > syscall(2f,2f,2f,2,bfbfe4ac) at syscall+0x127 > > > Xint0x80_syscall() at Xint0x80_syscall+0x1f > > > -- syscall (202, FreeBSD ELF32, __sysctl), eip=3D0x280cb7c3, > > > esp=3D0xbfbfe41c, ebp+0xbfbfe458 > > > > Looks like the ttys_list_mutex is busted. Hmm: > > > > struct tty * > > ttymalloc(struct tty *tp) > > { > > static int once; > > > > if (!once) { > > mtx_init(&tty_list_mutex, "ttylist", NULL, MTX_DEF); > > once++; > > } > > > > This code is not MP safe as multiple processors could attempt to call > > mtx_init() twice. The mutex should probably be initialized via > > MTX_SYSINIT instead. An alternative fix might be to change the code to > > work like this: > > > > if (once !=3D 2) { > > if (atomic_cmpset_int(&once, 0, 1)) { > > mtx_init(...); > > atomic_store_rel_int(&once, 2); > > } else while (once !=3D 2) > > cpu_spinwait(); > > } > > > > To ensure that 1) only one CPU can do the mtx_init() at a time and 2) > > that if any other CPU enters the function while another CPU is doing the > > mtx_init() it will wait until the mutex is initialized before proceedin= g. > > Any futher progress on this that I could test out? *poke*, anything more I can do to help with debugging/testing this problem? =2D-=20 Anish Mistry --nextPart1549572.oiUUMmHUBb Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (FreeBSD) iD8DBQBBXAA/xqA5ziudZT0RAl3tAJ0f4uQVQ/AOAo3oYgMQuexj+LVLoACfcwFr yJxPRLi30XCvuWVpWoPNq7M= =S0yJ -----END PGP SIGNATURE----- --nextPart1549572.oiUUMmHUBb--
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