Cast to a signed type before negating if we really want the result to be negative.

From: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 64ab6b69bca3821f27c88b515d209e7ac5424df1..32c69624e4b2bf2986e8ccb32d1bf561c81df4a5 100644 (file)
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -876,7 +876,7 @@ static int emulate_privileged_op(struct cpu_user_regs *regs)
                     PAGE_FAULT(regs->edi, USER_WRITE_FAULT);
                 break;
             }
-            regs->edi += (regs->eflags & EF_DF) ? -op_bytes : op_bytes;
+            regs->edi += (regs->eflags & EF_DF) ? -(int)op_bytes : op_bytes;
             break;
 
         case 0x6e: /* OUTSB */
@@ -902,7 +902,7 @@ static int emulate_privileged_op(struct cpu_user_regs *regs)
                 outl_user((u32)data, (u16)regs->edx, v, regs);
                 break;
             }
-            regs->esi += (regs->eflags & EF_DF) ? -op_bytes : op_bytes;
+            regs->esi += (regs->eflags & EF_DF) ? -(int)op_bytes : op_bytes;
             break;
         }
 

diff --git a/xen/arch/x86/x86_emulate.c b/xen/arch/x86/x86_emulate.c
index c829128e91039654236accd2338a31dcfb99b6a2..5bdafa9192eca5c3cecc461c343033db528aff77 100644 (file)
--- a/xen/arch/x86/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate.c
@@ -858,7 +858,7 @@ x86_emulate_memop(
                                          &dst.val, 8, ctxt)) != 0 )
                     goto done;
             }
-            register_address_increment(_regs.esp, -dst.bytes);
+            register_address_increment(_regs.esp, -(int)dst.bytes);
             if ( (rc = ops->write_std(register_address(_regs.ss, _regs.esp),
                                       dst.val, dst.bytes, ctxt)) != 0 )
                 goto done;
@@ -942,9 +942,9 @@ x86_emulate_memop(
                 goto done;
         }
         register_address_increment(
-            _regs.esi, (_regs.eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
+            _regs.esi, (_regs.eflags & EFLG_DF) ? -(int)dst.bytes : dst.bytes);
         register_address_increment(
-            _regs.edi, (_regs.eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
+            _regs.edi, (_regs.eflags & EFLG_DF) ? -(int)dst.bytes : dst.bytes);
         break;
     case 0xa6 ... 0xa7: /* cmps */
         DPRINTF("Urk! I don't handle CMPS.\n");
@@ -955,7 +955,7 @@ x86_emulate_memop(
         dst.ptr   = (unsigned long *)cr2;
         dst.val   = _regs.eax;
         register_address_increment(
-            _regs.edi, (_regs.eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
+            _regs.edi, (_regs.eflags & EFLG_DF) ? -(int)dst.bytes : dst.bytes);
         break;
     case 0xac ... 0xad: /* lods */
         dst.type  = OP_REG;
@@ -964,7 +964,7 @@ x86_emulate_memop(
         if ( (rc = ops->read_emulated(cr2, &dst.val, dst.bytes, ctxt)) != 0 )
             goto done;
         register_address_increment(
-            _regs.esi, (_regs.eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
+            _regs.esi, (_regs.eflags & EFLG_DF) ? -(int)dst.bytes : dst.bytes);
         break;
     case 0xae ... 0xaf: /* scas */
         DPRINTF("Urk! I don't handle SCAS.\n");