/* * emulator main execution loop * * Copyright (c) 2003-2005 Fabrice Bellard * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, see . */ /* Modified for Unicorn Engine by Nguyen Anh Quynh, 2015 */ #include "qemu/osdep.h" #include "cpu.h" #include "exec/exec-all.h" #include "tcg.h" #include "qemu/atomic.h" #include "qemu/timer.h" #include "sysemu/sysemu.h" #include "exec/address-spaces.h" #include "exec/tb-hash.h" #include "uc_priv.h" /* Execute a TB, and fix up the CPU state afterwards if necessary */ static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, TranslationBlock *itb) { CPUArchState *env = cpu->env_ptr; TCGContext *tcg_ctx = env->uc->tcg_ctx; uintptr_t ret; TranslationBlock *last_tb; int tb_exit; uint8_t *tb_ptr = itb->tc_ptr; // Unicorn: commented out //qemu_log_mask_and_addr(CPU_LOG_EXEC, itb->pc, // "Trace %p [" TARGET_FMT_lx "] %s\n", // itb->tc_ptr, itb->pc, lookup_symbol(itb->pc)); ret = tcg_qemu_tb_exec(env, tb_ptr); last_tb = (TranslationBlock *)(ret & ~TB_EXIT_MASK); tb_exit = ret & TB_EXIT_MASK; //trace_exec_tb_exit(last_tb, tb_exit); if (tb_exit > TB_EXIT_IDX1) { /* We didn't start executing this TB (eg because the instruction * counter hit zero); we must restore the guest PC to the address * of the start of the TB. */ CPUClass *cc = CPU_GET_CLASS(env->uc, cpu); // Unicorn: commented out //qemu_log_mask_and_addr(CPU_LOG_EXEC, last_tb->pc, // "Stopped execution of TB chain before %p [" // TARGET_FMT_lx "] %s\n", // last_tb->tc_ptr, last_tb->pc, // lookup_symbol(last_tb->pc)); if (cc->synchronize_from_tb) { // avoid sync twice when helper_uc_tracecode() already did this. if (env->uc->emu_counter <= env->uc->emu_count && !env->uc->stop_request && !env->uc->quit_request) { cc->synchronize_from_tb(cpu, last_tb); } } else { assert(cc->set_pc); // avoid sync twice when helper_uc_tracecode() already did this. if (env->uc->emu_counter <= env->uc->emu_count && !env->uc->quit_request) { cc->set_pc(cpu, last_tb->pc); } } } if (tb_exit == TB_EXIT_REQUESTED) { /* We were asked to stop executing TBs (probably a pending * interrupt. We've now stopped, so clear the flag. */ atomic_set(&cpu->tcg_exit_req, 0); } return ret; } /* Execute the code without caching the generated code. An interpreter could be used if available. */ static void cpu_exec_nocache(CPUState *cpu, int max_cycles, TranslationBlock *orig_tb, bool ignore_icount) { TranslationBlock *tb; CPUArchState *env = (CPUArchState *)cpu->env_ptr; /* Should never happen. We only end up here when an existing TB is too long. */ if (max_cycles > CF_COUNT_MASK) { max_cycles = CF_COUNT_MASK; } tb = tb_gen_code(cpu, orig_tb->pc, orig_tb->cs_base, orig_tb->flags, max_cycles | CF_NOCACHE); tb->orig_tb = orig_tb; /* execute the generated code */ // Unicorn: commented out //trace_exec_tb_nocache(tb, tb->pc); cpu_tb_exec(cpu, tb); tb_phys_invalidate(env->uc, tb, -1); tb_free(env->uc, tb); } static TranslationBlock *tb_htable_lookup(CPUState *cpu, target_ulong pc, target_ulong cs_base, uint32_t flags) { TCGContext *tcg_ctx = cpu->uc->tcg_ctx; CPUArchState *env = (CPUArchState *)cpu->env_ptr; TranslationBlock *tb, **tb_hash_head, **ptb1; uint32_t h; tb_page_addr_t phys_pc, phys_page1; /* find translated block using physical mappings */ phys_pc = get_page_addr_code(env, pc); phys_page1 = phys_pc & TARGET_PAGE_MASK; h = tb_hash_func(phys_pc, pc, flags); /* Start at head of the hash entry */ ptb1 = tb_hash_head = &tcg_ctx->tb_ctx.tb_phys_hash[h]; tb = *ptb1; while (tb) { if (tb->pc == pc && tb->page_addr[0] == phys_page1 && tb->cs_base == cs_base && tb->flags == flags) { if (tb->page_addr[1] == -1) { /* done, we have a match */ break; } else { /* check next page if needed */ target_ulong virt_page2 = (pc & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE; tb_page_addr_t phys_page2 = get_page_addr_code(env, virt_page2); if (tb->page_addr[1] == phys_page2) { break; } } } ptb1 = &tb->phys_hash_next; tb = *ptb1; } if (tb) { /* Move the TB to the head of the list */ *ptb1 = tb->phys_hash_next; tb->phys_hash_next = *tb_hash_head; *tb_hash_head = tb; } return tb; } static inline TranslationBlock *tb_find(CPUState *cpu, TranslationBlock *last_tb, int tb_exit) { CPUArchState *env = (CPUArchState *)cpu->env_ptr; TranslationBlock *tb; target_ulong cs_base, pc; uint32_t flags; bool have_tb_lock = false; /* we record a subset of the CPU state. It will always be the same before a given translated block is executed. */ cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags); // Unicorn: atomic_read used instead of atomic_rcu_read tb = atomic_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)]); if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base || tb->flags != flags)) { tb = tb_htable_lookup(cpu, pc, cs_base, flags); if (!tb) { /* mmap_lock is needed by tb_gen_code, and mmap_lock must be * taken outside tb_lock. As system emulation is currently * single threaded the locks are NOPs. */ mmap_lock(); // Unicorn: commented out //tb_lock(); have_tb_lock = true; /* There's a chance that our desired tb has been translated while * taking the locks so we check again inside the lock. */ tb = tb_htable_lookup(cpu, pc, cs_base, flags); if (!tb) { /* if no translated code available, then translate it now */ tb = tb_gen_code(cpu, pc, cs_base, flags, 0); } // Unicorn: commented out //tb_unlock(); mmap_unlock(); } /* We add the TB in the virtual pc hash table for the fast lookup */ atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)], tb); } #ifndef CONFIG_USER_ONLY /* We don't take care of direct jumps when address mapping changes in * system emulation. So it's not safe to make a direct jump to a TB * spanning two pages because the mapping for the second page can change. */ if (tb->page_addr[1] != -1) { last_tb = NULL; } #endif /* See if we can patch the calling TB. */ if (last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) { if (!have_tb_lock) { // Unicorn: commented out //tb_lock(); have_tb_lock = true; } /* Check if translation buffer has been flushed */ if (cpu->tb_flushed) { cpu->tb_flushed = false; } else if (!tb->invalid) { tb_add_jump(last_tb, tb_exit, tb); } } if (have_tb_lock) { // Unicorn: commented out //tb_unlock(); } return tb; } static inline bool cpu_handle_halt(CPUState *cpu) { if (cpu->halted) { if (!cpu_has_work(cpu)) { return true; } cpu->halted = 0; } return false; } static inline void cpu_handle_debug_exception(CPUState *cpu) { CPUClass *cc = CPU_GET_CLASS(cpu->uc, cpu); CPUWatchpoint *wp; if (!cpu->watchpoint_hit) { QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) { wp->flags &= ~BP_WATCHPOINT_HIT; } } cc->debug_excp_handler(cpu); } static inline bool cpu_handle_exception(struct uc_struct *uc, CPUState *cpu, int *ret) { struct hook *hook; if (cpu->exception_index >= 0) { if (uc->stop_interrupt && uc->stop_interrupt(cpu->exception_index)) { cpu->halted = 1; uc->invalid_error = UC_ERR_INSN_INVALID; *ret = EXCP_HLT; return true; } if (cpu->exception_index >= EXCP_INTERRUPT) { /* exit request from the cpu execution loop */ *ret = cpu->exception_index; if (*ret == EXCP_DEBUG) { cpu_handle_debug_exception(cpu); } cpu->exception_index = -1; return true; } else { #if defined(CONFIG_USER_ONLY) /* if user mode only, we simulate a fake exception which will be handled outside the cpu execution loop */ #if defined(TARGET_I386) CPUClass *cc = CPU_GET_CLASS(cpu); cc->do_interrupt(cpu); #endif *ret = cpu->exception_index; cpu->exception_index = -1; return true; #else bool catched = false; // Unicorn: call registered interrupt callbacks HOOK_FOREACH_VAR_DECLARE; HOOK_FOREACH(uc, hook, UC_HOOK_INTR) { ((uc_cb_hookintr_t)hook->callback)(uc, cpu->exception_index, hook->user_data); catched = true; } // Unicorn: If un-catched interrupt, stop executions. if (!catched) { cpu->halted = 1; uc->invalid_error = UC_ERR_EXCEPTION; *ret = EXCP_HLT; return true; } cpu->exception_index = -1; #endif } } return false; } static inline bool cpu_handle_interrupt(CPUState *cpu, TranslationBlock **last_tb) { CPUClass *cc = CPU_GET_CLASS(cpu->uc, cpu); int interrupt_request = cpu->interrupt_request; if (unlikely(interrupt_request)) { if (unlikely(cpu->singlestep_enabled & SSTEP_NOIRQ)) { /* Mask out external interrupts for this step. */ interrupt_request &= ~CPU_INTERRUPT_SSTEP_MASK; } if (interrupt_request & CPU_INTERRUPT_DEBUG) { cpu->interrupt_request &= ~CPU_INTERRUPT_DEBUG; cpu->exception_index = EXCP_DEBUG; return true; } if (interrupt_request & CPU_INTERRUPT_HALT) { cpu->interrupt_request &= ~CPU_INTERRUPT_HALT; cpu->halted = 1; cpu->exception_index = EXCP_HLT; return true; } #if defined(TARGET_I386) else if (interrupt_request & CPU_INTERRUPT_INIT) { X86CPU *x86_cpu = X86_CPU(cpu->uc, cpu); CPUArchState *env = &x86_cpu->env; cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0, 0); do_cpu_init(x86_cpu); cpu->exception_index = EXCP_HALTED; return true; } #else else if (interrupt_request & CPU_INTERRUPT_RESET) { cpu_reset(cpu); } #endif else { /* The target hook has 3 exit conditions: False when the interrupt isn't processed, True when it is, and we should restart on a new TB, and via longjmp via cpu_loop_exit. */ if (cc->cpu_exec_interrupt(cpu, interrupt_request)) { *last_tb = NULL; } /* The target hook may have updated the 'cpu->interrupt_request'; * reload the 'interrupt_request' value */ interrupt_request = cpu->interrupt_request; } if (interrupt_request & CPU_INTERRUPT_EXITTB) { cpu->interrupt_request &= ~CPU_INTERRUPT_EXITTB; /* ensure that no TB jump will be modified as the program flow was changed */ *last_tb = NULL; } } if (unlikely(cpu->exit_request)) { cpu->exit_request = 0; cpu->exception_index = EXCP_INTERRUPT; return true; } return false; } static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb, TranslationBlock **last_tb, int *tb_exit) { uintptr_t ret; /* execute the generated code */ ret = cpu_tb_exec(cpu, tb); tb = (TranslationBlock *)(ret & ~TB_EXIT_MASK); *tb_exit = ret & TB_EXIT_MASK; switch (*tb_exit) { case TB_EXIT_REQUESTED: /* Something asked us to stop executing chained TBs; just * continue round the main loop. Whatever requested the exit * will also have set something else (eg interrupt_request) * which we will handle next time around the loop. But we * need to ensure the tcg_exit_req read in generated code * comes before the next read of cpu->exit_request or * cpu->interrupt_request. */ smp_mb(); *last_tb = NULL; break; case TB_EXIT_ICOUNT_EXPIRED: { /* Instruction counter expired. */ #ifdef CONFIG_USER_ONLY abort(); #else int insns_left = cpu->icount_decr.u32; *last_tb = NULL; if (cpu->icount_extra && insns_left >= 0) { /* Refill decrementer and continue execution. */ cpu->icount_extra += insns_left; insns_left = MIN(0xffff, cpu->icount_extra); cpu->icount_extra -= insns_left; cpu->icount_decr.u16.low = insns_left; } else { if (insns_left > 0) { /* Execute remaining instructions. */ cpu_exec_nocache(cpu, insns_left, tb, false); // Unicorn: commented out //align_clocks(sc, cpu); } cpu->exception_index = EXCP_INTERRUPT; cpu_loop_exit(cpu); } break; #endif } default: *last_tb = tb; break; } } static void cpu_exec_step(struct uc_struct *uc, CPUState *cpu) { CPUArchState *env = (CPUArchState *)cpu->env_ptr; TranslationBlock *tb; target_ulong cs_base, pc; uint32_t flags; cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags); if (sigsetjmp(cpu->jmp_env, 0) == 0) { mmap_lock(); tb = tb_gen_code(cpu, pc, cs_base, flags, 1 | CF_NOCACHE | CF_IGNORE_ICOUNT); tb->orig_tb = NULL; mmap_unlock(); /* execute the generated code */ cpu_tb_exec(cpu, tb); tb_phys_invalidate(uc, tb, -1); tb_free(uc, tb); } else { /* We may have exited due to another problem here, so we need * to reset any tb_locks we may have taken but didn't release. * The mmap_lock is dropped by tb_gen_code if it runs out of * memory. */ #ifndef CONFIG_SOFTMMU // Unicorn: Commented out //tcg_debug_assert(!have_mmap_lock()); #endif // Unicorn: commented out //tb_lock_reset(); } } void cpu_exec_step_atomic(struct uc_struct *uc, CPUState *cpu) { // Unicorn: commented out //start_exclusive(); /* Since we got here, we know that parallel_cpus must be true. */ uc->parallel_cpus = false; cpu_exec_step(uc, cpu); uc->parallel_cpus = true; // Unicorn: commented out //end_exclusive(); } /* main execution loop */ int cpu_exec(struct uc_struct *uc, CPUState *cpu) { CPUArchState *env = cpu->env_ptr; CPUClass *cc = CPU_GET_CLASS(uc, cpu); int ret; if (cpu_handle_halt(cpu)) { return EXCP_HALTED; } atomic_mb_set(&uc->current_cpu, cpu); atomic_mb_set(&uc->tcg_current_rr_cpu, cpu); cc->cpu_exec_enter(cpu); cpu->exception_index = -1; env->invalid_error = UC_ERR_OK; /* prepare setjmp context for exception handling */ if (sigsetjmp(cpu->jmp_env, 0) != 0) { #if defined(__clang__) || !QEMU_GNUC_PREREQ(4, 6) /* Some compilers wrongly smash all local variables after * siglongjmp. There were bug reports for gcc 4.5.0 and clang. * Reload essential local variables here for those compilers. * Newer versions of gcc would complain about this code (-Wclobbered). */ cpu = uc->current_cpu; env = cpu->env_ptr; cc = CPU_GET_CLASS(uc, cpu); #else /* buggy compiler */ /* Assert that the compiler does not smash local variables. */ g_assert(cpu == current_cpu); g_assert(cc == CPU_GET_CLASS(cpu)); #endif /* buggy compiler */ cpu->can_do_io = 1; // Unicorn: commented out //tb_lock_reset(); } /* if an exception is pending, we execute it here */ while (!cpu_handle_exception(uc, cpu, &ret)) { TranslationBlock *last_tb = NULL; int tb_exit = 0; while (!cpu_handle_interrupt(cpu, &last_tb)) { TranslationBlock *tb = tb_find(cpu, last_tb, tb_exit); if (!tb) { // invalid TB due to invalid code? uc->invalid_error = UC_ERR_FETCH_UNMAPPED; ret = EXCP_HLT; break; } cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit); } } cc->cpu_exec_exit(cpu); // Unicorn: flush JIT cache to because emulation might stop in // the middle of translation, thus generate incomplete code. // TODO: optimize this for better performance tb_flush(cpu); return ret; }