From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta8.messagelabs.com (mail6.bemta8.messagelabs.com [216.82.243.55]) by kanga.kvack.org (Postfix) with ESMTP id 285326B0082 for ; Thu, 16 Jun 2011 03:14:41 -0400 (EDT) Subject: Re: Oops in VMA code From: Benjamin Herrenschmidt In-Reply-To: References: <47FAB15C-B113-40FD-9CE0-49566AACC0DF@suse.de> <96D27CEC-8492-49F2-913F-F587DEC5E95E@suse.de> Content-Type: text/plain; charset="UTF-8" Date: Thu, 16 Jun 2011 17:14:36 +1000 Message-ID: <1308208476.2516.67.camel@pasglop> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Linus Torvalds Cc: Alexander Graf , linux-mm@kvack.org, "linux-kernel@vger.kernel.org List" On Wed, 2011-06-15 at 23:54 -0700, Linus Torvalds wrote: > On Wed, Jun 15, 2011 at 11:20 PM, Alexander Graf wrote: > > > > On 16.06.2011, at 07:59, Linus Torvalds wrote: > >> > >> r26 has the value 0xc00090026236bbb0, and that "90" byte in the middle > >> there looks bogus. It's not a valid pointer any more, but if that "9" > >> had been a zero, it would have been. > > > > Please see my reply to Ben here. > > Your reply to Ben seems to say that 0xc00000026236bbb0 wouldn't have > been a valid address, because you don't have that much memory. > > But that's clearly not true. All the other registers have valid > pointers in them, and the stack pointer (r1) is c000000262987cd0, for > example. And that stack is clearly valid - if the kernel stack pointer > was corrupted, you'd never have gotten as far as reporting the oops. > > So you may have only 8GB of RAM in that machine, but if so, there's > some empty unmapped physical space. Because clearly your RAM is _not_ > limited to being mapped to below 0xc000000200000000. Right. It's a G5, RAM goes from 0...2G and 2G onward, with an IO hole from 2 to 4G. Cheers, Ben. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org