Date: Sat, 02 Aug 2003 19:13:47 -0700 From: "Evan Dower" <evantd@hotmail.com> To: grog@FreeBSD.org, tlambert2@mindspring.com Cc: current@freebsd.org Subject: Re: Yet another crash in FreeBSD 5.1 Message-ID: <BAY8-F95rxDvehhmJlq0000ee26@hotmail.com>
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I fear we may have gotten a bit off-topic. E >From: Greg 'groggy' Lehey <grog@FreeBSD.org> >To: Terry Lambert <tlambert2@mindspring.com> >CC: ticso@cicely.de, current@freebsd.org >Subject: Re: Yet another crash in FreeBSD 5.1 >Date: Sun, 3 Aug 2003 11:21:41 +0930 > >On Saturday, 2 August 2003 at 18:36:24 -0700, Terry Lambert wrote: > > Greg 'groggy' Lehey wrote: > >>> The information I gave him gets him to lines of source code, instead > >>> of just function names with strange hexadecimal numbers that resolve > >>> to instruction offsets that may be specific to his compile flags, > >>> date of checkout of the sources from CVS, etc.. > >> > >> The first step of the link above does the same thing. But it's only > >> the first step. > >>> by eyeballing the lines of source code in question and understanding > >>> the code around it well enough that you can tell *how* a pointer > >>> there could be NULL. My instructions *get* him those lines of > >>> source. > >> > >> You obviously still haven't read the reference. Do that first, and > >> come back when you have either understood things or are having > >> difficulty understanding. But don't shoot off your mouth without > >> knowing what's going on. > > > > I read the reference. > > > > How does it apply in cases like this one, where you don't have a > > vmcore file? > >You don't seem to have read the reference very well. It also asks for >other supporting information. That's the most important thing at the >moment. I know that because I've been there before, and I've looked >at a number of these dumps: it's almost certainly related to something >he's doing which is not normal. You don't know that, and that's >excusable, but it's not excusable that after four or five requests, >you still haven't RTFM'd. > > > The way I would approach finding this, with only: > > > > 1) The line of code where the failure occurred > > 2) The stack traceback, with no arguments > > 3) The sources for the code in the stack traceback > > > > would be to eyeball the code in #1, and try to figure out how > > I gould get to that point with that pointer having a NULL value, > > given my apriori knowledge of the forward call graph. > >You have that? > > > I would examine every intermediate conditional and function call > > that could effect the value of the pointer and cause it to be NULL > > at the point in question. > >Go for it. Once I get the log files, I'll start there. > > > One of the details I wish you would check is whether or not he has a > > vmcore file, or the ability to get one... > >We'll address that issue when it becomes necessary. > >Greg >-- >See complete headers for address and phone numbers ><< attach3 >> _________________________________________________________________ Tired of spam? Get advanced junk mail protection with MSN 8. http://join.msn.com/?page=features/junkmail
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