target/arm: Fix aa64 ldp register writeback

For "ldp x0, x1, [x0]", if the second load is on a second page and
the second page is unmapped, the exception would be raised with x0
already modified.  This means the instruction couldn't be restarted.

Cc: qemu-arm@nongnu.org
Cc: qemu-stable@nongnu.org
Reported-by: Andrew <andrew@fubar.geek.nz>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20170825224833.4463-1-richard.henderson@linaro.org
Fixes: https://bugs.launchpad.net/qemu/+bug/1713066
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
[PMM: tweaked comment format]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2017-09-04 15:21:56 +01:00 committed by Peter Maydell
parent f58f25599b
commit 3e4d91b94c
1 changed files with 17 additions and 12 deletions

View File

@ -2217,29 +2217,34 @@ static void disas_ldst_pair(DisasContext *s, uint32_t insn)
} else {
do_fp_st(s, rt, tcg_addr, size);
}
} else {
TCGv_i64 tcg_rt = cpu_reg(s, rt);
if (is_load) {
do_gpr_ld(s, tcg_rt, tcg_addr, size, is_signed, false,
false, 0, false, false);
} else {
do_gpr_st(s, tcg_rt, tcg_addr, size,
false, 0, false, false);
}
}
tcg_gen_addi_i64(tcg_addr, tcg_addr, 1 << size);
if (is_vector) {
tcg_gen_addi_i64(tcg_addr, tcg_addr, 1 << size);
if (is_load) {
do_fp_ld(s, rt2, tcg_addr, size);
} else {
do_fp_st(s, rt2, tcg_addr, size);
}
} else {
TCGv_i64 tcg_rt = cpu_reg(s, rt);
TCGv_i64 tcg_rt2 = cpu_reg(s, rt2);
if (is_load) {
TCGv_i64 tmp = tcg_temp_new_i64();
/* Do not modify tcg_rt before recognizing any exception
* from the second load.
*/
do_gpr_ld(s, tmp, tcg_addr, size, is_signed, false,
false, 0, false, false);
tcg_gen_addi_i64(tcg_addr, tcg_addr, 1 << size);
do_gpr_ld(s, tcg_rt2, tcg_addr, size, is_signed, false,
false, 0, false, false);
tcg_gen_mov_i64(tcg_rt, tmp);
tcg_temp_free_i64(tmp);
} else {
do_gpr_st(s, tcg_rt, tcg_addr, size,
false, 0, false, false);
tcg_gen_addi_i64(tcg_addr, tcg_addr, 1 << size);
do_gpr_st(s, tcg_rt2, tcg_addr, size,
false, 0, false, false);
}