[Qemu-devel] [PATCH] Bug in AMD64 emulation Was: [AMD64] Possible problem with the DF flag during the SYSCALL instruction

[Jakub Jermar]

Hi,

as no one has picked my previous report up yet, I am resending my patch 
again.  The patch fixes a bug in the way QEMU emulates AMD64 instruction 
called SYSCALL.  The problem appears to be stale DF variable.

Jakub

--- helper.c    2008-01-06 20:38:45.000000000 +0100
+++ helper.c.new        2008-03-20 22:39:17.000000000 +0100
@@ -1008,6 +1008,7 @@
                                DESC_S_MASK |
                                DESC_W_MASK | DESC_A_MASK);
         env->eflags &= ~env->fmask;
+       DF = 1 - (2 * ((env->eflags >> 10) & 1));
         if (code64)
             env->eip = env->lstar;
         else