[mips][microMIPS] Fix an invalid read for lwm32 and reserved reglist values.

[oota-llvm.git] / lib / Target / Mips / Disassembler / MipsDisassembler.cpp

diff --git a/lib/Target/Mips/Disassembler/MipsDisassembler.cpp b/lib/Target/Mips/Disassembler/MipsDisassembler.cpp
index 4aa0afd7e031176f9fae979b70a031996783ad20..27eb399ba96a1018c023450ff52a44670828f298 100644 (file)
--- a/lib/Target/Mips/Disassembler/MipsDisassembler.cpp
+++ b/lib/Target/Mips/Disassembler/MipsDisassembler.cpp
@@ -1919,11 +1919,17 @@ static DecodeStatus DecodeRegListOperand(MCInst &Inst,
   unsigned RegNum;
 
   unsigned RegLst = fieldFromInstruction(Insn, 21, 5);
+
   // Empty register lists are not allowed.
   if (RegLst == 0)
     return MCDisassembler::Fail;
 
   RegNum = RegLst & 0xf;
+
+  // RegLst values 10-15, and 26-31 are reserved.
+  if (RegNum > 9)
+    return MCDisassembler::Fail;
+
   for (unsigned i = 0; i < RegNum; i++)
     Inst.addOperand(MCOperand::createReg(Regs[i]));