Date: Tue, 29 Jun 2004 14:49:46 -0400 From: Brian Fundakowski Feldman <green@FreeBSD.org> To: Daniel Lang <dl@leo.org> Cc: John Baldwin <jhb@FreeBSD.org> Subject: Re: kern/68442: panic - acquiring duplicate lock of same type: "sleepq chain" Message-ID: <20040629184946.GE1144@green.homeunix.org> In-Reply-To: <20040629183557.GA77135@atrbg11.informatik.tu-muenchen.de> References: <20040628202434.GA73213@atrbg11.informatik.tu-muenchen.de> <20040629153921.GE75577@atrbg11.informatik.tu-muenchen.de> <200406291200.12030.jhb@FreeBSD.org> <20040629163028.GM75577@atrbg11.informatik.tu-muenchen.de> <20040629170014.GC1144@green.homeunix.org> <20040629183557.GA77135@atrbg11.informatik.tu-muenchen.de>
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On Tue, Jun 29, 2004 at 08:35:57PM +0200, Daniel Lang wrote: > Hi Brian, > > Brian Fundakowski Feldman wrote on Tue, Jun 29, 2004 at 01:00:14PM -0400: > [..] > > You can find it out without using gdb, too. This will work for > > only main kernel symbols, but you can do something similar for > > KLDs. Say I want to find a symbol that's in the main kernel object: > > > > $ objdump -t /boot/kernel/kernel | ruby -ne 'fields = $_.split; if fields[3] == ".text" and fields[2] == "F" and 0xc048a800.between?(fields[0].hex, fields[0].hex + fields[4].hex) then puts $_ end' > > c048a7ac l F .text 0000006b cbb_removal > [..] > > Thanks for that hint, but Colin suggested to use "addr2line", which > produced some result. Maybe addr2line does a similar thing > as your objdump/ruby script: Yeah, as long as it's in the main kernel object and you have debug symbols. > So I have a line of code for the failing address: > > # addr2line -e kernel.debug 0xc053932b > /usr/src/sys/kern/subr_witness.c:898 > > which is (in my kernel): > > [..] > lock1 = &(*lock_list)->ll_children[(*lock_list)->ll_count - 1]; > [..] > > Well, I'm not sure if this is a big help. I doubt there is a bug > in witness code. Looks like a lock was cleared out/freed/whatever but not actually deinitialized first? > I'll cross-check with gdb to see if there is the same > result. Too bad I couldn't get a crashdump. > > (What hurts most, is, that in one occasion I had a ddb prompt > and could call doadump() successfully. But after reboot, damn > /var was full, so savecore could not write it to disk, argl!). You can make /var/crash a symlink to a directory with more space. -- Brian Fundakowski Feldman \'[ FreeBSD ]''''''''''\ <> green@FreeBSD.org \ The Power to Serve! \ Opinions expressed are my own. \,,,,,,,,,,,,,,,,,,,,,,\
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