Date: Mon, 19 May 2003 16:41:30 +0200
From: Alex Riesen <alexander.riesen@synopsys.COM>
To: mikpe@csd.uu.se
Cc: sfr@canb.auug.org.au, linux-kernel@vger.kernel.org,
       linux-laptop@vger.kernel.org
Subject: Re: 2.5.69+bk: oops in apmd after waking up from suspend mode
Message-ID: <20030519144130.GM32559@Synopsys.COM>
Reply-To: alexander.riesen@synopsys.COM
References: <200305191216.h4JCGONj015081@harpo.it.uu.se> <20030519123119.GA20385@Synopsys.COM>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20030519123119.GA20385@Synopsys.COM>
Organization: Synopsys, Inc.
User-Agent: Mutt/1.5.4i
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1266
Lines: 34

Alex Riesen, Mon, May 19, 2003 14:31:19 +0200:
> > >EIP is at fix_processor_context+0x5f/0x100
> > >Process kapmd (pid: 4, threadinfo=c5f0e000 task=c5fbc640)
> > 
> > After receiving Alex' .config and gcc version (3.2.3), I've been
> > able to decipher this. current->mm is NULL in the kapmd task. The call
> > 
> > 	load_LDT(&current->mm->context);	/* This does lldt */
> > 
> > in fix_processor_context() computes the address of context as
> > (current->mm)+0x7c, which is 0x7c. load_LDT_nolock() dereferences
> > 0x7c+0x14 (void *segments = pc->ldt) and the oops follows.
> > 
> > As to _why_ kapmd's current->mm is NULL, I don't know. It isn't
> > when I test APM suspend in 2.5.69-bk. A lot of code dereferences
> > current->mm without checking, so I guess current->mm==NULL is a bug.
> > 
> 
> i just go and try it with the latest -bk.
> 

no change. Still oopses.

Is it safe to trace this path with printks? I'm about to put them in,
but a good advice could probably come before the compilation finishes.

-alex


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/