linux-kernel - Re: Commit for mm/page_alloc.c breaks boot process on my machine

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20080201210656.174030@gmx.net>
Date:	Fri, 01 Feb 2008 22:06:56 +0100
From:	"Gerhard Pircher" <gerhard_pircher@....net>
To:	Mel Gorman <mel@....ul.ie>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Commit for mm/page_alloc.c breaks boot process on my machine


-------- Original-Nachricht --------
> Datum: Fri, 1 Feb 2008 20:25:18 +0000
> Von: Mel Gorman <mel@....ul.ie>
> An: Gerhard Pircher <gerhard_pircher@....net>
> CC: linux-kernel@...r.kernel.org
> Betreff: Re: Commit for mm/page_alloc.c breaks boot process on my machine

> I meant uninitialised memory but I also wonder could something like this
> happen if you are trying to use memory that doesn't exist. i.e. you are
> trying to access more memory than you really have but you indicate later
> that this is not the case.
Good question. The memory is in the physical address range from 0x00000000
to 0x60000000 (1536MB).

> > > 2. Any chance of seeing a dmesg log?
> > That's a little bit of a problem. The kernel log in memory doesn't show
> > any kernel oops, but is also fragmented (small fragments seem to have
> > been overwritten with 0x0).
> 
> err, that doesn't sound very healthy.
Yeah, I know. But the platform code hasn't changed much when porting it
from arch/ppc to arch/powerpc. That's why I'm a little bit lost in this
case. :-)

> > Well, I can't answer this question. The kernel currently locks up when
> > loading the INIT program. But that is another problem (I still have to
> > bisect it) and doesn't seem to be related to this problem.
> 
> INIT would be the first MOVABLE allocation so it would be using memory
> at the end of the physical adddress range. i.e. the crash happens when
> memory towards the end and the only difference between the patch applied
> and reverted is when it happens.
Oh, that sounds interesting!

> Could you try booting with 16MB less memory using mem=?
I started the kernel with 512MB RAM (mem=496) and 1.5GB (mem=1520). The
kernel oopes in both cases with a "Unable to handle kernel paging request
for data address 0xbffff000", followed by a "Oops: kernel access of bad
area, sig 11" message. The end of the stack trace shows the start_here()
function.
I'm not a PowerPC expert, but if 0xbffff000 is a virtual address, then
it would be in the user program address space, right? If it is a physical
address, then it is somewhere in the unallocated PCI address space.

Gerhard

-- 
Ist Ihr Browser Vista-kompatibel? Jetzt die neuesten 
Browser-Versionen downloaden: http://www.gmx.net/de/go/browser
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/