diff options
| -rw-r--r-- | libdex/InstrUtils.c | 79 |
1 files changed, 34 insertions, 45 deletions
diff --git a/libdex/InstrUtils.c b/libdex/InstrUtils.c index ae4d7bdd5..660e9f3ab 100644 --- a/libdex/InstrUtils.c +++ b/libdex/InstrUtils.c @@ -1063,10 +1063,12 @@ void dexDecodeInstruction(const InstructionFormat* fmts, const u2* insns, DecodedInstruction* pDec) { u2 inst = *insns; + OpCode opCode = (OpCode) INST_INST(inst); + InstructionFormat format = dexGetInstrFormat(fmts, opCode); - pDec->opCode = (OpCode) INST_INST(inst); + pDec->opCode = opCode; - switch (dexGetInstrFormat(fmts, pDec->opCode)) { + switch (format) { case kFmt10x: // op /* nothing to do; copy the AA bits out for the verifier */ pDec->vA = INST_AA(inst); @@ -1130,7 +1132,7 @@ void dexDecodeInstruction(const InstructionFormat* fmts, const u2* insns, pDec->vB = INST_B(inst); pDec->vC = FETCH(1); break; - case kFmt30t: // op +AAAAAAAA + case kFmt30t: // op +AAAAAAAA pDec->vA = FETCH(1) | ((u4) FETCH(2) << 16); // signed 32-bit value break; case kFmt31t: // op vAA, +BBBBBBBB @@ -1148,6 +1150,7 @@ void dexDecodeInstruction(const InstructionFormat* fmts, const u2* insns, break; case kFmt35c: // op {vC, vD, vE, vF, vG}, thing@BBBB case kFmt35ms: // [opt] invoke-virtual+super + case kFmt35mi: // [opt] inline invoke { /* * Note that the fields mentioned in the spec don't appear in @@ -1157,7 +1160,7 @@ void dexDecodeInstruction(const InstructionFormat* fmts, const u2* insns, * range formats (3rc and friends). * * Bottom line: The argument count is always in vA, and the - * method constant is always in vB. + * method constant (or equivalent) is always in vB. */ u2 regList; int i, count; @@ -1166,49 +1169,38 @@ void dexDecodeInstruction(const InstructionFormat* fmts, const u2* insns, pDec->vB = FETCH(1); regList = FETCH(2); - if (pDec->vA > 5) { - LOGW("Invalid arg count in 35c/35ms (%d)\n", pDec->vA); - goto bail; - } count = pDec->vA; - if (count == 5) { + + /* + * Copy the argument registers into the arg[] array, and + * also copy the first argument (if any) into vC. (The + * DecodedInstruction structure doesn't have separate + * fields for {vD, vE, vF, vG}, so there's no need to make + * copies of those.) Note that cases 5..2 fall through. + */ + switch (count) { + case 5: { + if (format == kFmt35mi) { + /* A fifth arg is verboten for inline invokes. */ + LOGW("Invalid arg count in 35mi (5)\n"); + goto bail; + } /* - * Per note above, the 5th arg comes from the A field in the + * Per note at the top of this format decoder, the + * fifth argument comes from the A field in the * instruction, but it's labeled G in the spec. */ pDec->arg[4] = INST_A(inst); - count--; - } - for (i = 0; i < count; i++) { - pDec->arg[i] = regList & 0x0f; - regList >>= 4; } - /* copy arg[0] to vC; we don't have vD/vE/vF, so ignore those */ - if (pDec->vA > 0) - pDec->vC = pDec->arg[0]; - } - break; - case kFmt35mi: // [opt] inline invoke - { - /* See note under case 35c, above. */ - u2 regList; - int i; - - pDec->vA = INST_B(inst); // This is labeled A in the spec. - pDec->vB = FETCH(1); - regList = FETCH(2); - - if (pDec->vA > 4) { - LOGW("Invalid arg count in 3inline (%d)\n", pDec->vA); + case 4: pDec->arg[3] = (regList >> 12) & 0x0f; + case 3: pDec->arg[2] = (regList >> 8) & 0x0f; + case 2: pDec->arg[1] = (regList >> 4) & 0x0f; + case 1: pDec->vC = pDec->arg[0] = regList & 0x0f; break; + case 0: break; // Valid, but no need to do anything. + default: + LOGW("Invalid arg count in 35c/35ms/35mi (%d)\n", count); goto bail; } - for (i = 0; i < (int) pDec->vA; i++) { - pDec->arg[i] = regList & 0x0f; - regList >>= 4; - } - /* copy arg[0] to vC; we don't have vD/vE/vF, so ignore those */ - if (pDec->vA > 0) - pDec->vC = pDec->arg[0]; } break; case kFmt35fs: // [opt] invoke-interface @@ -1223,14 +1215,11 @@ void dexDecodeInstruction(const InstructionFormat* fmts, const u2* insns, break; case kFmt51l: // op vAA, #+BBBBBBBBBBBBBBBB pDec->vA = INST_AA(inst); - pDec->vB_wide = FETCH(1); - pDec->vB_wide |= (u8)FETCH(2) << 16; - pDec->vB_wide |= (u8)FETCH(3) << 32; - pDec->vB_wide |= (u8)FETCH(4) << 48; + pDec->vB_wide = FETCH(1) | ((u8) FETCH(2) << 16) + | ((u8) FETCH(3) << 32) | ((u8) FETCH(4) << 48); break; default: - LOGW("Can't decode unexpected format %d (op=%d)\n", - dexGetInstrFormat(fmts, pDec->opCode), pDec->opCode); + LOGW("Can't decode unexpected format %d (op=%d)\n", format, opCode); assert(false); break; } |