From: Simon Marlow <marlowsd@gmail.com>
Date: Mon, 24 May 2010 10:55:47 +0000 (+0000)
Subject: Add a missing UNTAG_CLOSURE, causing bus errors on Sparc
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=b2e840ee0c95fb549d40950f43cc6e4afc177a46;p=ghc-hetmet.git

Add a missing UNTAG_CLOSURE, causing bus errors on Sparc
We just about got away with this on x86 which isn't
alignment-sensitive.  The result of the memory load is compared
against a few different values, but there is a fallback case that
happened to be the right thing when the pointer was tagged.  A good
bug to find, nonetheless.
---

diff --git a/rts/Messages.c b/rts/Messages.c
index 5a1e5bd..91ee9a6 100644
--- a/rts/Messages.c
+++ b/rts/Messages.c
@@ -183,9 +183,10 @@ nat messageBlackHole(Capability *cap, MessageBlackHole *msg)
         return 0;
     }
 
-    // we know at this point that the closure 
+    // The blackhole must indirect to a TSO, a BLOCKING_QUEUE, an IND,
+    // or a value.
 loop:
-    p = ((StgInd*)bh)->indirectee;
+    p = UNTAG_CLOSURE(((StgInd*)bh)->indirectee);
     info = p->header.info;
 
     if (info == &stg_IND_info)