Memory protection was Re: change log for rtems (2011-10-21)

[Joel Sherrill]

On 10/25/2011 04:53 PM, Peter Dufault wrote:
> On Oct 25, 2011, at 4:18 , Joel Sherrill wrote:
>
>> Stack protection is likely to result in a violation of the POSIX
>> process/thread model.  RTEMS is best compared to a thread
>> implementation in a user space library in POSIX process terms.
>>
> I wouldn't be so sure.  I've worked on such systems in the past (pre-POSIX) and found them very valuable.
>
> You will need to recode to take advantage - e.g. pthread_mutex_init() will fail when it determines an object isn't shared, etc.  That's not a drawback since a protected stack system is going to need to be coded from the ground up, but you'll still be able to use familiar interfaces subject to understandable restrictions.
>
I think we agree.  I didn't say they weren't useful -- just that
it broke the POSIX memory model.  So you can't do it by default
since you have to follow additional rules.

Existing code can be expected to potentially break.


> Peter
> -----------------
> Peter Dufault
> HD Associates, Inc.      Software and System Engineering
>


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