target/m68k: Perform writback before modifying SR

Writes to SR may change security state, which may involve
a swap of %ssp with %usp as reflected in %a7.  Finish the
writeback of %sp@+ before swapping stack pointers.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1206
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20220913142818.7802-3-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This commit is contained in:
Richard Henderson 2022-09-13 15:28:18 +01:00 committed by Laurent Vivier
parent 24ec52f91d
commit 214c6002d0

View File

@ -2285,9 +2285,9 @@ static void gen_set_sr_im(DisasContext *s, uint16_t val, int ccr_only)
tcg_gen_movi_i32(QREG_CC_N, val & CCF_N ? -1 : 0);
tcg_gen_movi_i32(QREG_CC_X, val & CCF_X ? 1 : 0);
} else {
TCGv sr = tcg_const_i32(val);
gen_helper_set_sr(cpu_env, sr);
tcg_temp_free(sr);
/* Must writeback before changing security state. */
do_writebacks(s);
gen_helper_set_sr(cpu_env, tcg_constant_i32(val));
}
set_cc_op(s, CC_OP_FLAGS);
}
@ -2297,6 +2297,8 @@ static void gen_set_sr(DisasContext *s, TCGv val, int ccr_only)
if (ccr_only) {
gen_helper_set_ccr(cpu_env, val);
} else {
/* Must writeback before changing security state. */
do_writebacks(s);
gen_helper_set_sr(cpu_env, val);
}
set_cc_op(s, CC_OP_FLAGS);