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From: Olav Haugan <ohaugan@codeaurora.org>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: ngupta@vflare.org, sjenning@linux.vnet.ibm.com,
	linux-kernel@vger.kernel.org, minchan@kernel.org,
	linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH] staging: zsmalloc: Ensure handle is never 0 on success
Date: Thu, 07 Nov 2013 14:57:04 -0800	[thread overview]
Message-ID: <527C1AC0.2040206@codeaurora.org> (raw)
In-Reply-To: <20131107030640.GD8482@kroah.com>

On 11/6/2013 7:06 PM, Greg KH wrote:
> On Wed, Nov 06, 2013 at 04:00:02PM -0800, Olav Haugan wrote:
>> On 11/5/2013 5:56 PM, Greg KH wrote:
>>> On Tue, Nov 05, 2013 at 04:54:12PM -0800, Olav Haugan wrote:
>>>> zsmalloc encodes a handle using the page pfn and an object
>>>> index. On some hardware platforms the pfn could be 0 and this
>>>> causes the encoded handle to be 0 which is interpreted as an
>>>> allocation failure.
>>>
>>> What platforms specifically have this issue?
>>
>> Currently some of Qualcomm SoC's have physical memory that starts at
>> address 0x0 which causes this problem.
> 
> Then say this, and list the exact SoC's that can have this problem so
> people know how to evaluate the bugfix and see if it is relevant for
> their systems.
> 
>> I believe this could be a problem
>> on any platforms if memory is configured to be starting at physical
>> address 0x0 for these platforms.
> 
> Have you seen this be a problem?  So it's just a theoretical issue at
> this point in time?

Yes, I can consistently reproduce it. It is not just theoretical.

Thanks,

Olav Haugan

-- 
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation

  reply	other threads:[~2013-11-07 22:57 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-06  0:54 [PATCH] staging: zsmalloc: Ensure handle is never 0 on success Olav Haugan
2013-11-06  1:17 ` David Cohen
2013-11-06 20:56   ` Nitin Gupta
2013-11-06 23:46     ` Olav Haugan
2013-11-06  1:56 ` Greg KH
2013-11-06 21:09   ` Nitin Gupta
2013-11-06 22:10     ` Greg KH
2013-11-06 23:46       ` Nitin Gupta
2013-11-07  3:05         ` Greg KH
2013-11-07  0:00   ` Olav Haugan
2013-11-07  3:06     ` Greg KH
2013-11-07 22:57       ` Olav Haugan [this message]
2013-11-07  7:04 Minchan Kim
2013-11-07 17:06 ` Luigi Semenzato
2013-11-07 17:36   ` Luigi Semenzato
2013-11-08  2:02   ` Greg KH
2013-11-07 17:10 ` Rik van Riel
2013-11-08 10:44 ` Bob Liu
2013-11-12 15:41 ` Minchan Kim
2013-11-13  2:42   ` Greg KH
2013-11-13  6:24     ` Nitin Gupta
2013-11-14  4:00   ` Hugh Dickins
2013-11-14 16:21     ` Seth Jennings
2013-11-15  0:47       ` Bob Liu
2013-11-15  0:31     ` Minchan Kim

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