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From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] Armv5 target
Date: Wed, 2 Feb 2005 01:26:37 +0000
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> > +    /* XXX: locking issue */
> > +    if (is_write && page_unprotect(address, pc, puc)) {
> > +        return 1;
> > +    }
> >      /* XXX: do more */
> >      return 0;
> >  }
>
> Sort of. Self-modifying code (e.g. stack trampolines) are still broken, and
> the patch above should work.
>
> However I just tested it and it doesn't seem to work any more. It seems
> that the SEGV handler is being passed an address of 0, rather than the
> actual faulting location.
>
> This may be a host kernel/libc bug.

I just tried on a few different machines, and this is a host kernel bug 
specific to one particular kernel (custom 2.6.9).

However I don't think this is the best solution.  arm-linux has an instruction 
cache flush syscall, so we should be hooking into that instead.

Paul