From ebee6129cdaeeaa3931bbd6d078a984c84d261f1 Mon Sep 17 00:00:00 2001 From: Reid Kleckner Date: Thu, 19 Nov 2015 21:51:55 +0000 Subject: Fix UMRs in Mips disassembler on invalid instruction streams The Insn and Size local variables were used without initialization. llvm-svn: 253607 --- llvm/lib/Target/Mips/Disassembler/MipsDisassembler.cpp | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'llvm/lib/Target/Mips/Disassembler') diff --git a/llvm/lib/Target/Mips/Disassembler/MipsDisassembler.cpp b/llvm/lib/Target/Mips/Disassembler/MipsDisassembler.cpp index f25df1ef715..f9601839b44 100644 --- a/llvm/lib/Target/Mips/Disassembler/MipsDisassembler.cpp +++ b/llvm/lib/Target/Mips/Disassembler/MipsDisassembler.cpp @@ -867,6 +867,8 @@ DecodeStatus MipsDisassembler::getInstruction(MCInst &Instr, uint64_t &Size, if (IsMicroMips) { Result = readInstruction16(Bytes, Address, Size, Insn, IsBigEndian); + if (Result == MCDisassembler::Fail) + return MCDisassembler::Fail; if (hasMips32r6()) { DEBUG(dbgs() << "Trying MicroMipsR616 table (16-bit instructions):\n"); @@ -913,12 +915,17 @@ DecodeStatus MipsDisassembler::getInstruction(MCInst &Instr, uint64_t &Size, Size = 4; return Result; } + // This is an invalid instruction. Let the disassembler move forward by the + // minimum instruction size. + Size = 2; return MCDisassembler::Fail; } Result = readInstruction32(Bytes, Address, Size, Insn, IsBigEndian, false); - if (Result == MCDisassembler::Fail) + if (Result == MCDisassembler::Fail) { + Size = 4; return MCDisassembler::Fail; + } if (hasCOP3()) { DEBUG(dbgs() << "Trying COP3_ table (32-bit opcodes):\n"); @@ -979,6 +986,7 @@ DecodeStatus MipsDisassembler::getInstruction(MCInst &Instr, uint64_t &Size, return Result; } + Size = 4; return MCDisassembler::Fail; } -- cgit v1.2.3