Re: [Lightning] PPC problem

[Paolo Bonzini]

Eli Barzilay wrote:
> There was a PPC problem that we've just fixed, and I'm forwarding it
> here in case it's not fixed in the lightning repository:
> 
> (Quoting Matthew Flatt)
> 
> The problem was a bug in lightning's icache-flushing code (used by the
> JIT) It could walk one word past the end of an allocated page onto an
> unallocated page. The bug was exposed by yesterday's change to the way
> that memory is allocated to hold JIT-generated native code.
> 
> The fix is in "lightning/ppc/funcs.h": subtract 1 from `end' here:
> 
>      end -= ((long) end - 1) & (cache_line_size - 1);

Thanks, here's what I applied:

diff --git a/lightning/ppc/funcs.h b/lightning/ppc/funcs.h
index 9f3df90..ae9301f 100644
--- a/lightning/ppc/funcs.h
+++ b/lightning/ppc/funcs.h
@@ -67,6 +67,9 @@ jit_flush_code(void *start, void *end)
         break;
   }

+  /* Point end to the last byte being flushed.  */
+  end   =(void*)( (long)(end - 1));
+
   start =(void*)( (long)start - (((long) start) & (cache_line_size - 1)));
   end   =(void*)( (long)end   - (((long) end) & (cache_line_size - 1)));

Paolo