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Re: Cannot unwind through MIPS signal frames with ICACHE_REFILLS_WORKAROUND_WAR


On Nov 13, 2007 3:37 PM, Kevin D. Kissell <kevink@mips.com> wrote:
> Franck a dit:
> > > Another reason is to get rid of the classic trampoline the kernel installs
> > > on the stack.  On some multiprocessor systems it requires a cacheflush
> > > operation to be performed on all processors which is expensive.  Having
> > > the trampoline in a vDSO would solve that.
> > >
> >
> > And the stack wouldn't need to have exec permission anymore.
>
> True, though it should perhaps be noted that currently it's only on 4KSc/Sd
> systems (which I know you work on) where it's even possible for the stack
> *not* to have exec permissions, since the classical MIPS MMU gives
> execute permission to any page that is readable.
>

Well, the noexec stack is pretty usefull I think. I can't believe it
will be limited to these 2 systems in the near future...

-- 
               Franck


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