From: Keir Fraser <keir.fraser@citrix.com>
Date: Tue, 22 Apr 2008 10:44:56 +0000 (+0100)
Subject: x86_emulate: Disable writeback if BSF/BSR are passed zero input.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14215^2~146
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22?a=commitdiff_plain;h=63f197e31d1f313613f5342fd566324e1fee14fc;p=xen.git

x86_emulate: Disable writeback if BSF/BSR are passed zero input.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
---

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c
index 2b7ddeffbb..8d8db35820 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -3134,7 +3134,11 @@ x86_emulate(
               : "=r" (dst.val), "=q" (zf)
               : "r" (src.val), "1" (0) );
         _regs.eflags &= ~EFLG_ZF;
-        _regs.eflags |= zf ? EFLG_ZF : 0;
+        if ( zf )
+        {
+            _regs.eflags |= EFLG_ZF;
+            dst.type = OP_NONE;
+        }
         break;
     }
 
@@ -3144,7 +3148,11 @@ x86_emulate(
               : "=r" (dst.val), "=q" (zf)
               : "r" (src.val), "1" (0) );
         _regs.eflags &= ~EFLG_ZF;
-        _regs.eflags |= zf ? EFLG_ZF : 0;
+        if ( zf )
+        {
+            _regs.eflags |= EFLG_ZF;
+            dst.type = OP_NONE;
+        }
         break;
     }