Re: [Powertop] A series of patches towards limiting memory corruption and foot print

[Sergey Senozhatsky <sergey.senozhatsky at gmail.com>]

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On (05/01/14 14:11), Kalowsky, Daniel wrote:
>    Sorry about a second post, looks like email stripped the attachements. 
>    Second attempt here.

Hello,

it's much easier to review/comment/etc if a patch is inlined in your
email, in plain text. (http://www.tux.org/lkml/#s1-10)

care to resend using git send-email?
thanks.

	-ss

>     
> 
>    From: PowerTop [mailto:powertop-bounces(a)lists.01.org] On Behalf Of
>    Kalowsky, Daniel
>    Sent: Tuesday, April 29, 2014 5:15 PM
>    To: powertop(a)lists.01.org
>    Subject: [Powertop] A series of patches towards limiting memory corruption
>    and foot print
> 
>     
> 
>    Hi Powertop,
> 
>     
> 
>    I’ve been working with the interactive mode and have run into cases where
>    powertop will crash due to a series of memory corruptions.  The following
>    series of patches have helped to reduce the frequency of the issue,
>    although not completely solved it.  The issues arise much faster on
>    platforms where there are constrained amounts of RAM to work within.
> 
>     
> 
>    Patch 1 – When shutting down the interactive display, the display bits of
>    memory is not correctly released.  This patch provides a method for
>    correctly doing so. 
> 
>     
> 
>    Patch 2 – Solving a documented memory leak with a non-elegant solution. 
>    The path either adds the bundle to the stack, or it forgets about it.  If
>    it is forgotten about, make sure to clear that memory before moving on. 
>    This is done with a simple flag variable being set. 
> 
>     
> 
>    Patch 3 – When the tuning window is updated, the current pointer is just
>    set adrift and not properly free’d.  This patch catches that issue and
>    removes the dangling pointer by holding a reference to the pointer until
>    it is reset or specifically free’d.
> 
>     
> 
>    Patch 4 – Someone actually added in the code to create a onetime
>    pretty-print array, this patch just puts it to use by setting the
>    variable. 
> 
>     
> 
>    Patch 5 – Limiting the buffer copy to the size of the allocated buffer
>    with snprintf.
> 
>     
> 
>    Patch 6 – There exist some processes and entries that can and do extend
>    beyond the length of these buffers.  This limits those entries so as not
>    to corrupt other memory on the system when in interactive mode. 
> 
>     
> 
>    Patch 7 – This is an untested patch, but follows along the same lines of
>    Patch 6.  It applies the same principals only for the report method. 
> 
>     
> 
>    Patch 8 – Creates a clean_shutdown function that can be used to cleanup
>    the memory space at shutdown time.  Calls upon parts of Patch 1 to make
>    this happen. 
> 
>     
> 
>    There will more than likely be some more patches in the future as time
>    permits. 


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