target/arm/translate-a64: Don't underdecode add/sub extended register

In the "add/subtract (extended register)" encoding group, the "opt"
field in bits [23:22] must be zero. Correctly UNDEF the unallocated
encodings where this field is not zero.

Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Message-id: 20190125182626.9221-6-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2019-02-01 14:55:44 +00:00
parent 9c72b68ad7
commit 4f61106614

View File

@ -4201,6 +4201,7 @@ static void disas_add_sub_ext_reg(DisasContext *s, uint32_t insn)
int imm3 = extract32(insn, 10, 3);
int option = extract32(insn, 13, 3);
int rm = extract32(insn, 16, 5);
int opt = extract32(insn, 22, 2);
bool setflags = extract32(insn, 29, 1);
bool sub_op = extract32(insn, 30, 1);
bool sf = extract32(insn, 31, 1);
@ -4209,7 +4210,7 @@ static void disas_add_sub_ext_reg(DisasContext *s, uint32_t insn)
TCGv_i64 tcg_rd;
TCGv_i64 tcg_result;
if (imm3 > 4) {
if (imm3 > 4 || opt != 0) {
unallocated_encoding(s);
return;
}