Date: Tue, 6 Jun 1995 08:42:58 +0200 (MET DST) From: J Wunsch <j@uriah.heep.sax.de> To: freebsd-hackers@freebsd.org (FreeBSD hackers) Subject: Re: kernel page fault while doing tar to /dev/rft0 Message-ID: <199506060642.IAA06472@uriah.heep.sax.de> In-Reply-To: <199506060230.TAA25146@gndrsh.aac.dev.com> from "Rodney W. Grimes" at Jun 5, 95 07:30:29 pm
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As Rodney W. Grimes wrote: > > > ft is a pointer to the floppy t_y_pe structure. > > Ah.. okay, suggest we rename it to type then! fd->type->secsize makes > a lot more since when reading this code!!! Look into the code please, Rod: there's already something named `type' within struct fd_data, just one line above! (It's the drive type code, as opposed to the drive type data structure, describing drive geometry.) > > Patches should be reviewed by someone (if any :-) who is familiar with > > the code. > > Agreed, but it still fails on the fact the hunk is offset which means > the purson is not testing against -current code. Calm down. Steve always told that he's running 2.0R, and the bug has creeped in before 2.0. Furthermore, Steve was only reviewing my suggestion, which i've done based on -current. Back to the topic: anything regarding a floppy tape drive will not fall below the lines #if'ed. So it has been apparent to me that the bug must be somewhere in the variable initialization above. Since the panics experienced a NULL pointer dereferencation, fd->ft was the most suspect one. Beware that, unlike my first suggestion, it's not possible to move all those 5 lines (starting at line 1079 :) of variable initialization below the #if NFT > 0 block, since at least fdc (and hence fd and fdu) have to be initialized for the second check (tape already busy). -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ Never trust an operating system you don't have sources for. ;-)
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