[mythtv-users] SUID root might hang your myth box

[Brad Fuller]

Phil Blundell wrote:

>on Thu, Nov 18, 2004 at 01:48:40AM -0800, Joe Barnhart wrote:
>  
>
>>Why does this seemingly innocuous setting cause such a
>>huge problem?  Why is it recommended?  Does the
>>benefit outweigh the stress on my box turning it off
>>and on a bunch of times trying to get the setting to
>>work?
>>    
>>
>
>Making mythfrontsend setuid root allows it to set the video playback
>thread to "realtime" priority, which means it will always have
>precedence over any other task on the system.  This avoids any
>stuttering that might be caused if the playback thread is delayed for
>too long by other processes, which is why it's normally desirable.
>
>But, as you've discovered, if mythfrontend crashes in such a way that
>the playback thread is stuck in a tight loop, it will consume all the
>CPU time and no other task will ever be allowed to run.  Since this
>includes ssh and the shell, there is no way to kill the errant thread.
>The only way to regain control is to reset the machine.
>
>If you aren't experiencing any video playback problems, there is no
>benefit in making the executable setuid.  On the other hand, if Myth is
>working correctly, there should be no harm in making it setuid either.
>  
>
How would one change it back?
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