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encode: Fix erroneous encoding of SREG push/pop

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This commit is contained in:
Alexis Engelke
2021-03-23 13:25:30 +01:00
parent 5faa90a292
commit cf8d1be15f
2 changed files with 12 additions and 2 deletions
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6
encode.c
View File

@@ -348,6 +348,10 @@ fe_enc64_impl(uint8_t** restrict buf, uint64_t mnem, FeOp op0, FeOp op1,
opc |= OPC_67;
if (UNLIKELY(mnem & FE_SEG_MASK))
opc |= (mnem & FE_SEG_MASK) << (OPC_SEG_IDX - 16);
if (UNLIKELY(desc->enc == ENC_S)) {
if ((op_reg_idx(op0) << 3 & 0x20) != (opc & 0x20)) goto next;
opc |= op_reg_idx(op0) << 3;
}
if (ei->immctl > 0) {
imm = ops[ei->immidx];
@@ -372,8 +376,6 @@ fe_enc64_impl(uint8_t** restrict buf, uint64_t mnem, FeOp op0, FeOp op1,
if (enc_mr(buf, opc, ops[ei->modrm^3], modreg, desc->immsz)) goto fail;
} else if (ei->modreg) {
if (enc_o(buf, opc, ops[ei->modreg^3])) goto fail;
} else if (UNLIKELY(desc->enc == ENC_S)) {
if (enc_opc(buf, opc | (op_reg_idx(op0) << 3))) goto fail;
} else {
if (enc_opc(buf, opc)) goto fail;
}

8
tests/test_encode.c
View File

@@ -70,6 +70,14 @@ main(int argc, char** argv)
TEST("\x54", FE_PUSHr, FE_SP);
TEST("\x41\x57", FE_PUSHr, FE_R15);
TEST("\x41\x50", FE_PUSHr, FE_R8);
TEST("", FE_PUSHr, FE_ES);
TEST("", FE_PUSH16r, FE_ES);
TEST("", FE_PUSHr, FE_CS);
TEST("", FE_PUSH16r, FE_CS);
TEST("", FE_PUSHr, FE_SS);
TEST("", FE_PUSH16r, FE_SS);
TEST("", FE_PUSHr, FE_DS);
TEST("", FE_PUSH16r, FE_DS);
TEST("\x0f\xa0", FE_PUSHr, FE_FS);
TEST("\x66\x0f\xa0", FE_PUSH16r, FE_FS);
TEST("\x0f\xa8", FE_PUSHr, FE_GS);