Philippe Mathieu-Daudé <phi...@linaro.org> writes:
> On 19/10/22 13:35, Alex Bennée wrote: >> The s390x EXecute instruction is a bit weird as we synthesis the >> executed instruction from what we have stored in memory. When plugins >> are enabled this breaks because we detect the ld_code2() loading from >> a non zero offset without the rest of the instruction being there. >> Work around this with a special helper to inform the rest of the >> translator about the instruction so things stay consistent. >> Signed-off-by: Alex Bennée <alex.ben...@linaro.org> >> Cc: Richard Henderson <richard.hender...@linaro.org> >> --- >> include/exec/translator.h | 17 +++++++++++++++++ >> target/s390x/tcg/translate.c | 4 ++++ >> 2 files changed, 21 insertions(+) >> diff --git a/include/exec/translator.h b/include/exec/translator.h >> index 3b77f5f4aa..156f568701 100644 >> --- a/include/exec/translator.h >> +++ b/include/exec/translator.h >> @@ -211,6 +211,23 @@ translator_ldq_swap(CPUArchState *env, DisasContextBase >> *db, >> return ret; >> } >> +/** >> + * translator_fake_ldw - fake instruction load >> + * @insn16: 2 byte instruction >> + * @pc: program counter of instruction >> + * >> + * This is a special case helper used where the instruction we are >> + * about to translate comes from somewhere else (e.g. being >> + * re-synthesised for s390x "ex"). It ensures we update other areas of >> + * the translator with details of the executed instruction. >> + */ >> + >> +static inline void translator_fake_ldw(uint16_t insn16, abi_ptr pc) >> +{ >> + plugin_insn_append(pc, &insn16, sizeof(insn16)); >> +} >> + >> + >> /* >> * Return whether addr is on the same page as where disassembly started. >> * Translators can use this to enforce the rule that only single-insn >> diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c >> index 1d2dddab1c..a07b8b2d23 100644 >> --- a/target/s390x/tcg/translate.c >> +++ b/target/s390x/tcg/translate.c >> @@ -6317,12 +6317,16 @@ static const DisasInsn *extract_insn(CPUS390XState >> *env, DisasContext *s) >> if (unlikely(s->ex_value)) { >> /* Drop the EX data now, so that it's clear on exception paths. */ >> TCGv_i64 zero = tcg_const_i64(0); >> + int i; >> tcg_gen_st_i64(zero, cpu_env, offsetof(CPUS390XState, ex_value)); >> tcg_temp_free_i64(zero); >> /* Extract the values saved by EXECUTE. */ >> insn = s->ex_value & 0xffffffffffff0000ull; >> ilen = s->ex_value & 0xf; >> + for (i = 0; i < ilen; i += 2) { > > Is it worth guarding with #ifdef CONFIG_PLUGIN? I don't think so. It all gets nicely dead coded away when plugins aren't enabled. > >> + translator_fake_ldw(extract64(insn, 48 - (i * 8), 16), pc + i); >> + } >> op = insn >> 56; >> } else { >> insn = ld_code2(env, s, pc); -- Alex Bennée