You are right. I'll send patch v2 shortly. Thank you for the reply. Richard Henderson <richard.hender...@linaro.org> 於 2024年2月7日 週三 上午4:24寫道：
> On 2/6/24 23:18, Jason Chien wrote: > > The original implementation sets $pc to the address read from the jump > > vector table first and links $ra with the address of the next instruction > > after the updated $pc. After jumping to the updated $pc and executing the > > next ret instruction, the program jumps to $ra, which is in the same > > function currently executing, which results in an infinite loop. > > This commit reverses the two action. Firstly, $ra is updated with the > > address of the next instruction after $pc, and sets $pc to the address > > read from the jump vector table. > > This is unlikely to be correct in the case the vector table read faults, > leaving $ra updated. > > I guess this got broken with CF_PCREL. Anyway, the solution is to use a > temporary... > > > - /* > > - * Update pc to current for the non-unwinding exception > > - * that might come from cpu_ld*_code() in the helper. > > - */ > > - gen_update_pc(ctx, 0); > > - gen_helper_cm_jalt(cpu_pc, cpu_env, tcg_constant_i32(a->index)); > > ... here and then ... > > > @@ -307,6 +300,13 @@ static bool trans_cm_jalt(DisasContext *ctx, > arg_cm_jalt *a) > > gen_set_gpr(ctx, xRA, succ_pc); > > } > > > > ... copy the temp to cpu_pc here. > > > tcg_gen_lookup_and_goto_ptr(); > > ctx->base.is_jmp = DISAS_NORETURN; > > return true; > > > > r~ >
