[Qemu-devel] [6100] When -icount is used and a TB is recompiled due to an IO access

[Qemu-devel] [6100] When -icount is used and a TB is recompiled due to an IO access

[Paul Brook]

Revision: 6100
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6100
Author:   pbrook
Date:     2008-12-19 12:49:13 +0000 (Fri, 19 Dec 2008)

Log Message:
-----------
When -icount is used and a TB is recompiled due to an IO access 
shortly after an IRQ has been raised, env->exception_index will still be set 
to EXCP_IRQ when cpu_io_recompile calls cpu_resume_from_signal.
This causes qemu to repeat the IRQ trap, with disasterous consequences.

I suspect this "works" most of the time because linux tends to drop back to
svc mode before doing actual IRQ processing, and be fairly
tolerant of spurious IRQ traps.

Signed-off-by: Paul Brook <paul@codesourcery.com>

Modified Paths:
--------------
    trunk/cpu-exec.c

Modified: trunk/cpu-exec.c
===================================================================
--- trunk/cpu-exec.c	2008-12-19 12:39:00 UTC (rev 6099)
+++ trunk/cpu-exec.c	2008-12-19 12:49:13 UTC (rev 6100)
@@ -86,6 +86,7 @@
 #endif
     }
 #endif
+    env->exception_index = -1;
     longjmp(env->jmp_env, 1);
 }