Re: [libreoffice-users] opening powerpoint files restart the computer

Hi :)
I think ram issues are the 2nd most likely cause of crashes.  If it is the cause then you probably 
find other programs also seem to cause crashes too.  

The 1st most likely cause has usually been some bad version of Java.  Each time Oracle release a 
version of Java they claim it is safe and that we must all upgrade to it asap or experience all 
sorts of unspeakable horrors.  Then a few weeks later they admit there are problems with their 
newer one too.  Then they release yet another and claim we must all upgrade to that.  Rinse and 
repeat.  If you are not using a Screen-Reader or other Accessibility tool then you can probably 
switch Java off without noticing any difference except that your system is more stable.  

Tools - Options - Advanced / Java

At the top UNtick the box that asks if you want to use Java.  You will see all the versions of java 
currently installed on your system listed in the big white box under that.  Really your system 
should have no more than 2 but preferably none.  Note that in the USA their "Homeland security" 
apparently sent out a warning to companies that they should remove Java from their systems because 
it was creating such huge problems so often.  I'm not often in agreement with Homeland Security.  I 
switched Java off in as many apps/programs as possible for about a month before i finally 
uninstalled it from all machines.  I was a bit worried that i might have needed it for something 
but after a month found that nothing at my place needed it.  Of course some companies still run job 
adverts for Java programmers ...

Like i said, Ram is probably 2nd and after that is possibly wobbly graphics card issues.  
Overheating often leads to machines just cutting power.  In the bios you might be able to set what 
temperature causes an automatic shut-down.  I hooovered one persons laptop grills and keyboard 
solving that one for her!! It was a bit of a risk but worked out well.  For desktops it's usually 
easier to take the side of the case off and gently remove the choking dust.  Be careful !!
a) it causes almost unstoppable coughing if inhaled.  Drinking water doesn't seem to help but 
something heavier like mango juice or milk usually does the trick.  
b) the plastic nozzle of the hoover holds enough charge to seriously zap most of the components on 
almost any mbord.  Even fingers hold enough static to significantly reduce lifespans of components 
although normal skin has enough unnoticeable oil to create other problems too.  

Generally with those sorts of things you will notice other programs also cause crashes.  


Going off on a tangent ... 

Win7 has some new clever way of filling up nearly all available Ram by caching what it thinks you 
will need next or might need quickly (such as things you just closed).  So, some of that 35% will 
just be cached items.  One of the big features about Win7 was that it was smaller than it's 
predecessor.  Each newer version of Windows has usually been hugely more demanding in terms of 
resources than any previous version of Windows.  With Win7 one of the boasts was that it's almost 
as small and efficient as Xp.  (ie smaller than Vista).  A 1st for MS.  

Wrt deliberately written malware embedded in documents i think that is usually only possible 
through Macros.  The Macro code has to find a way of being executed as "Administrator" (in 
Gnu&Linux we say SuperUser or Root User  (hence commands such as su or sudo)).  I think LO Macros 
run in some safer way that denies them access to that level of privilege even when a Windows user 
is running as Admin all the time.  Win7 is much better at working well as normal user so users are 
not all forced into running as Admin user all the time.  Again a 1st for MS.  While MS Office 
macros have been used as an attack-vector for quite a lot of malware over the years LO/OOo Macros 
never have been afaik.  MS Office macros use a different language so they don't run in LO or any of 
the other competitors to MSO.  

In Windows it seems to be considered ok for apps/programs to suddenly go off and download updates 
and then install them and even force a reboot.  Generally programs are polite enough to ask before 
forcing a reboot but if you dare to say no they will keep popping up with the demand every few 
minutes until you obey.  In Gnu&Linux such behaviour would be considered a serious security issue.  

Regards from 
Tom :)  





> ________________________________
> From: Andrew Brown <andrewbr@icon.co.za>
> To: Gabriel Risterucci <cleyfaye@gmail.com> 
> Cc: Demétrio Soares <demetrio.soares@gmail.com>; users@global.libreoffice.org 
> Sent: Sunday, 21 July 2013, 17:52
> Subject: Re: [libreoffice-users] opening powerpoint files restart the computer
>
>
> Hi Gabriel
>
> I agree, you make some valid points, but the MS hive (collection of the 
> boot code plus apps running in memory in one big monolith file, unlike 
> the Linux kernel with separate "clients" communicating with the kernel, 
> all separate), is not as robust as we would like to believe, even in 
> Windows 7 and 8. So as you covered in your reply, any bad data files 
> forcing it's host app, as in this case LO with a presentation data file, 
> to exceed it's memory boundaries, will cause the processor and microcode 
> to force a reboot intentionally or accidentally, due to creating 
> instability with the rest of the memory content, the hive. This is the 
> weakness of the MS way of doing things.
>
> As to my coverage of malware in the data files, it could cause a system 
> crash and reboot, if the malware code is written badly or incomplete.
>
> I also noticed that Demétrio Soares is running Windows 7 32 bit on only 
> 1.5MB of RAM, this in itself could be the problem. Although Windows 7  
> can run on  1.5GB of RAM, it is recommended to run it on at least 2GB, 
> and even better with 3 or 4GB. The 4GB will be a bit of a waste as a 
> 32bit system can only see a physical max of 3.2GB, so installing 4GB 
> would not see or use the last 800MB (as layman terms as I can explain 
> it). With only 1.5GB of RAM, the O/S is using at least 1GB of this RAM 
> leaving 500MB for apps and data file, so I would also expect a system 
> crash if the data file was a large one. As an example I am using Windows 
> 7 64bit with 6GB of RAM, and I am consuming 35% (2GB) of this RAM right 
> now as I type this email, Thunderbird open, Firefox open, and not much 
> else except some system resources running.
>
> Regards
>
> Andrew Brown
>
> On 21/07/2013 06:25 PM, Gabriel Risterucci wrote:
> > While it's totally true that malicious code might be embedded in 
> > anything (especially ms formats... but we won't talk about this :)), I 
> > doubt it would trigger a reaction as bad as a reboot, especially under 
> > recent OS.
> > Crashing a user program is very unlikely to cause a system reboot, 
> > except if it call some regular reboot code, that would trigger a 
> > "clean" reboot, windows closing and stuff. Most likely output is 
> > simply the program crashing/getting in an unstable state.
> >
> > As I said, it's not completely ruling out the possibility of a 
> > catastrophic crash caused by some code issue, but it's fearly 
> > reasonnable to suppose that loading this file make LO expand to use 
> > more memory than usual, touching a faulty area. If the computer 
> > usually work without issue, maybe the ppt file is very large, or very 
> > complex, or the LO loading routine doesn't handle it nicely and cause 
> > the memory cost to increase.
> >
> > It would be interesting to know wether the reboot is "hard" (instant 
> > black screen) or soft (windows closing down normally).
> > Also, if the ppt file isn't sensitive, it would be useful to put it on 
> > some kind of file sharing site for people to try loading it.
> >
> > -- 
> > Cley Faye
> > http://cleyfaye.net
> >
> >
> > 2013/7/21 Andrew Brown <andrewbr@icon.co.za <mailto:andrewbr@icon.co.za>>
> >
> >      Hello
> >
> >      My two cents worth would rather be to focus on the actual
> >      Powerpoint data file that is the source of the problem, when
> >      attempted to being opened. If it has any corruption in it, or
> >      possibly a piece of malware made to disguise and represent itself
> >      as a Powerpoint presentation, then I would accept it crashing and
> >      forcing a reboot of the PC, especially if there is no malware
> >      protection in place, on a Windows system especially. Virus writers
> >      can easily embed bad and malicious code into documents,
> >      presentations and spreadsheets.
> >
> >      Try another known working presentation data file, and see if this
> >      also causes the crash with LO and the PC, if not, then you know
> >      where your source of your problem is.
> >
> >      Cheers
> >
> >      Andrew Brown
> >
> >
> >      On 21/07/2013 05:20 PM, Gabriel Risterucci wrote:
> >
> >          There is not much stuff (if any) in LO that could cause a
> >          reboot of a
> >          computer. Although it's not possible to completely rule out a
> >          LO issue, I'd
> >          suggest you run some memory testing program (like memtest86+),
> >          as it's much
> >          more likely that your issue is related to faulty memory/hardware.
>
>
> -- 
> To unsubscribe e-mail to: users+unsubscribe@global.libreoffice.org
> Problems? http://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/
> Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette
> List archive: http://listarchives.libreoffice.org/global/users/
> All messages sent to this list will be publicly archived and cannot be deleted
-- 
To unsubscribe e-mail to: users+unsubscribe@global.libreoffice.org
Problems? http://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/
Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette
List archive: http://listarchives.libreoffice.org/global/users/
All messages sent to this list will be publicly archived and cannot be deleted