Index: llvm/trunk/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
===================================================================
--- llvm/trunk/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ llvm/trunk/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -486,7 +486,7 @@
     }
   }
 
-  Size = 0;
+  Size = 4;
   return MCDisassembler::Fail;
 }
 
Index: llvm/trunk/test/tools/llvm-objdump/ARM/invalid-instruction.s
===================================================================
--- llvm/trunk/test/tools/llvm-objdump/ARM/invalid-instruction.s
+++ llvm/trunk/test/tools/llvm-objdump/ARM/invalid-instruction.s
@@ -0,0 +1,9 @@
+@RUN: llvm-mc -triple arm-unknown-linux -filetype=obj %s | llvm-objdump -d - | FileCheck %s
+
+.text
+  b l0
+  .inst 0xffffffff
+l0:
+
+@CHECK:            0: 00 00 00 ea   b #0 <l0>
+@CHECK-NEXT:       4: ff ff ff ff  <unknown>