| /* |
| * i386 emulator main execution loop |
| * |
| * Copyright (c) 2003 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, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| #include "exec-i386.h" |
| #include "disas.h" |
| |
| //#define DEBUG_EXEC |
| #define DEBUG_FLUSH |
| //#define DEBUG_SIGNAL |
| |
| /* main execution loop */ |
| |
| /* maximum total translate dcode allocated */ |
| #define CODE_GEN_BUFFER_SIZE (2048 * 1024) |
| //#define CODE_GEN_BUFFER_SIZE (128 * 1024) |
| #define CODE_GEN_MAX_SIZE 65536 |
| #define CODE_GEN_ALIGN 16 /* must be >= of the size of a icache line */ |
| |
| /* threshold to flush the translated code buffer */ |
| #define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - CODE_GEN_MAX_SIZE) |
| |
| #define CODE_GEN_MAX_BLOCKS (CODE_GEN_BUFFER_SIZE / 64) |
| #define CODE_GEN_HASH_BITS 15 |
| #define CODE_GEN_HASH_SIZE (1 << CODE_GEN_HASH_BITS) |
| |
| typedef struct TranslationBlock { |
| unsigned long pc; /* simulated PC corresponding to this block (EIP + CS base) */ |
| unsigned long cs_base; /* CS base for this block */ |
| unsigned int flags; /* flags defining in which context the code was generated */ |
| uint8_t *tc_ptr; /* pointer to the translated code */ |
| struct TranslationBlock *hash_next; /* next matching block */ |
| } TranslationBlock; |
| |
| TranslationBlock tbs[CODE_GEN_MAX_BLOCKS]; |
| TranslationBlock *tb_hash[CODE_GEN_HASH_SIZE]; |
| int nb_tbs; |
| |
| uint8_t code_gen_buffer[CODE_GEN_BUFFER_SIZE]; |
| uint8_t *code_gen_ptr; |
| |
| /* thread support */ |
| |
| #ifdef __powerpc__ |
| static inline int testandset (int *p) |
| { |
| int ret; |
| __asm__ __volatile__ ( |
| "0: lwarx %0,0,%1 ;" |
| " xor. %0,%3,%0;" |
| " bne 1f;" |
| " stwcx. %2,0,%1;" |
| " bne- 0b;" |
| "1: " |
| : "=&r" (ret) |
| : "r" (p), "r" (1), "r" (0) |
| : "cr0", "memory"); |
| return ret; |
| } |
| #endif |
| |
| #ifdef __i386__ |
| static inline int testandset (int *p) |
| { |
| char ret; |
| long int readval; |
| |
| __asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0" |
| : "=q" (ret), "=m" (*p), "=a" (readval) |
| : "r" (1), "m" (*p), "a" (0) |
| : "memory"); |
| return ret; |
| } |
| #endif |
| |
| #ifdef __s390__ |
| static inline int testandset (int *p) |
| { |
| int ret; |
| |
| __asm__ __volatile__ ("0: cs %0,%1,0(%2)\n" |
| " jl 0b" |
| : "=&d" (ret) |
| : "r" (1), "a" (p), "0" (*p) |
| : "cc", "memory" ); |
| return ret; |
| } |
| #endif |
| |
| #ifdef __alpha__ |
| int testandset (int *p) |
| { |
| int ret; |
| unsigned long one; |
| |
| __asm__ __volatile__ ("0: mov 1,%2\n" |
| " ldl_l %0,%1\n" |
| " stl_c %2,%1\n" |
| " beq %2,1f\n" |
| ".subsection 2\n" |
| "1: br 0b\n" |
| ".previous" |
| : "=r" (ret), "=m" (*p), "=r" (one) |
| : "m" (*p)); |
| return ret; |
| } |
| #endif |
| |
| #ifdef __sparc__ |
| static inline int testandset (int *p) |
| { |
| int ret; |
| |
| __asm__ __volatile__("ldstub [%1], %0" |
| : "=r" (ret) |
| : "r" (p) |
| : "memory"); |
| |
| return (ret ? 1 : 0); |
| } |
| #endif |
| |
| int global_cpu_lock = 0; |
| |
| void cpu_lock(void) |
| { |
| while (testandset(&global_cpu_lock)); |
| } |
| |
| void cpu_unlock(void) |
| { |
| global_cpu_lock = 0; |
| } |
| |
| /* exception support */ |
| /* NOTE: not static to force relocation generation by GCC */ |
| void raise_exception_err(int exception_index, int error_code) |
| { |
| /* NOTE: the register at this point must be saved by hand because |
| longjmp restore them */ |
| #ifdef reg_EAX |
| env->regs[R_EAX] = EAX; |
| #endif |
| #ifdef reg_ECX |
| env->regs[R_ECX] = ECX; |
| #endif |
| #ifdef reg_EDX |
| env->regs[R_EDX] = EDX; |
| #endif |
| #ifdef reg_EBX |
| env->regs[R_EBX] = EBX; |
| #endif |
| #ifdef reg_ESP |
| env->regs[R_ESP] = ESP; |
| #endif |
| #ifdef reg_EBP |
| env->regs[R_EBP] = EBP; |
| #endif |
| #ifdef reg_ESI |
| env->regs[R_ESI] = ESI; |
| #endif |
| #ifdef reg_EDI |
| env->regs[R_EDI] = EDI; |
| #endif |
| env->exception_index = exception_index; |
| env->error_code = error_code; |
| longjmp(env->jmp_env, 1); |
| } |
| |
| /* short cut if error_code is 0 or not present */ |
| void raise_exception(int exception_index) |
| { |
| raise_exception_err(exception_index, 0); |
| } |
| |
| void cpu_x86_tblocks_init(void) |
| { |
| if (!code_gen_ptr) { |
| code_gen_ptr = code_gen_buffer; |
| } |
| } |
| |
| /* flush all the translation blocks */ |
| static void tb_flush(void) |
| { |
| int i; |
| #ifdef DEBUG_FLUSH |
| printf("gemu: flush code_size=%d nb_tbs=%d avg_tb_size=%d\n", |
| code_gen_ptr - code_gen_buffer, |
| nb_tbs, |
| (code_gen_ptr - code_gen_buffer) / nb_tbs); |
| #endif |
| nb_tbs = 0; |
| for(i = 0;i < CODE_GEN_HASH_SIZE; i++) |
| tb_hash[i] = NULL; |
| code_gen_ptr = code_gen_buffer; |
| /* XXX: flush processor icache at this point */ |
| } |
| |
| /* find a translation block in the translation cache. If not found, |
| return NULL and the pointer to the last element of the list in pptb */ |
| static inline TranslationBlock *tb_find(TranslationBlock ***pptb, |
| unsigned long pc, |
| unsigned long cs_base, |
| unsigned int flags) |
| { |
| TranslationBlock **ptb, *tb; |
| unsigned int h; |
| |
| h = pc & (CODE_GEN_HASH_SIZE - 1); |
| ptb = &tb_hash[h]; |
| #if 0 |
| /* XXX: hack to handle 16 bit modyfing code */ |
| if (flags & (1 << GEN_FLAG_CODE32_SHIFT)) |
| #endif |
| for(;;) { |
| tb = *ptb; |
| if (!tb) |
| break; |
| if (tb->pc == pc && tb->cs_base == cs_base && tb->flags == flags) |
| return tb; |
| ptb = &tb->hash_next; |
| } |
| *pptb = ptb; |
| return NULL; |
| } |
| |
| /* allocate a new translation block. flush the translation buffer if |
| too many translation blocks or too much generated code */ |
| static inline TranslationBlock *tb_alloc(void) |
| { |
| TranslationBlock *tb; |
| if (nb_tbs >= CODE_GEN_MAX_BLOCKS || |
| (code_gen_ptr - code_gen_buffer) >= CODE_GEN_BUFFER_MAX_SIZE) |
| tb_flush(); |
| tb = &tbs[nb_tbs++]; |
| return tb; |
| } |
| |
| int cpu_x86_exec(CPUX86State *env1) |
| { |
| int saved_T0, saved_T1, saved_A0; |
| CPUX86State *saved_env; |
| #ifdef reg_EAX |
| int saved_EAX; |
| #endif |
| #ifdef reg_ECX |
| int saved_ECX; |
| #endif |
| #ifdef reg_EDX |
| int saved_EDX; |
| #endif |
| #ifdef reg_EBX |
| int saved_EBX; |
| #endif |
| #ifdef reg_ESP |
| int saved_ESP; |
| #endif |
| #ifdef reg_EBP |
| int saved_EBP; |
| #endif |
| #ifdef reg_ESI |
| int saved_ESI; |
| #endif |
| #ifdef reg_EDI |
| int saved_EDI; |
| #endif |
| int code_gen_size, ret; |
| void (*gen_func)(void); |
| TranslationBlock *tb, **ptb; |
| uint8_t *tc_ptr, *cs_base, *pc; |
| unsigned int flags; |
| |
| /* first we save global registers */ |
| saved_T0 = T0; |
| saved_T1 = T1; |
| saved_A0 = A0; |
| saved_env = env; |
| env = env1; |
| #ifdef reg_EAX |
| saved_EAX = EAX; |
| EAX = env->regs[R_EAX]; |
| #endif |
| #ifdef reg_ECX |
| saved_ECX = ECX; |
| ECX = env->regs[R_ECX]; |
| #endif |
| #ifdef reg_EDX |
| saved_EDX = EDX; |
| EDX = env->regs[R_EDX]; |
| #endif |
| #ifdef reg_EBX |
| saved_EBX = EBX; |
| EBX = env->regs[R_EBX]; |
| #endif |
| #ifdef reg_ESP |
| saved_ESP = ESP; |
| ESP = env->regs[R_ESP]; |
| #endif |
| #ifdef reg_EBP |
| saved_EBP = EBP; |
| EBP = env->regs[R_EBP]; |
| #endif |
| #ifdef reg_ESI |
| saved_ESI = ESI; |
| ESI = env->regs[R_ESI]; |
| #endif |
| #ifdef reg_EDI |
| saved_EDI = EDI; |
| EDI = env->regs[R_EDI]; |
| #endif |
| |
| /* put eflags in CPU temporary format */ |
| CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); |
| DF = 1 - (2 * ((env->eflags >> 10) & 1)); |
| CC_OP = CC_OP_EFLAGS; |
| env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); |
| env->interrupt_request = 0; |
| |
| /* prepare setjmp context for exception handling */ |
| if (setjmp(env->jmp_env) == 0) { |
| for(;;) { |
| if (env->interrupt_request) { |
| raise_exception(EXCP_INTERRUPT); |
| } |
| #ifdef DEBUG_EXEC |
| if (loglevel) { |
| /* XXX: save all volatile state in cpu state */ |
| /* restore flags in standard format */ |
| env->regs[R_EAX] = EAX; |
| env->regs[R_EBX] = EBX; |
| env->regs[R_ECX] = ECX; |
| env->regs[R_EDX] = EDX; |
| env->regs[R_ESI] = ESI; |
| env->regs[R_EDI] = EDI; |
| env->regs[R_EBP] = EBP; |
| env->regs[R_ESP] = ESP; |
| env->eflags = env->eflags | cc_table[CC_OP].compute_all() | (DF & DF_MASK); |
| cpu_x86_dump_state(env, logfile, 0); |
| env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); |
| } |
| #endif |
| /* we compute the CPU state. We assume it will not |
| change during the whole generated block. */ |
| flags = env->seg_cache[R_CS].seg_32bit << GEN_FLAG_CODE32_SHIFT; |
| flags |= env->seg_cache[R_SS].seg_32bit << GEN_FLAG_SS32_SHIFT; |
| flags |= (((unsigned long)env->seg_cache[R_DS].base | |
| (unsigned long)env->seg_cache[R_ES].base | |
| (unsigned long)env->seg_cache[R_SS].base) != 0) << |
| GEN_FLAG_ADDSEG_SHIFT; |
| if (!(env->eflags & VM_MASK)) { |
| flags |= (env->segs[R_CS] & 3) << GEN_FLAG_CPL_SHIFT; |
| } else { |
| /* NOTE: a dummy CPL is kept */ |
| flags |= (1 << GEN_FLAG_VM_SHIFT); |
| flags |= (3 << GEN_FLAG_CPL_SHIFT); |
| } |
| flags |= (env->eflags & IOPL_MASK) >> (12 - GEN_FLAG_IOPL_SHIFT); |
| flags |= (env->eflags & TF_MASK) << (GEN_FLAG_TF_SHIFT - 8); |
| cs_base = env->seg_cache[R_CS].base; |
| pc = cs_base + env->eip; |
| tb = tb_find(&ptb, (unsigned long)pc, (unsigned long)cs_base, |
| flags); |
| if (!tb) { |
| /* if no translated code available, then translate it now */ |
| /* XXX: very inefficient: we lock all the cpus when |
| generating code */ |
| cpu_lock(); |
| tc_ptr = code_gen_ptr; |
| ret = cpu_x86_gen_code(code_gen_ptr, CODE_GEN_MAX_SIZE, |
| &code_gen_size, pc, cs_base, flags); |
| /* if invalid instruction, signal it */ |
| if (ret != 0) { |
| cpu_unlock(); |
| raise_exception(EXCP06_ILLOP); |
| } |
| tb = tb_alloc(); |
| *ptb = tb; |
| tb->pc = (unsigned long)pc; |
| tb->cs_base = (unsigned long)cs_base; |
| tb->flags = flags; |
| tb->tc_ptr = tc_ptr; |
| tb->hash_next = NULL; |
| code_gen_ptr = (void *)(((unsigned long)code_gen_ptr + code_gen_size + CODE_GEN_ALIGN - 1) & ~(CODE_GEN_ALIGN - 1)); |
| cpu_unlock(); |
| } |
| #ifdef DEBUG_EXEC |
| if (loglevel) { |
| fprintf(logfile, "Trace 0x%08lx [0x%08lx] %s\n", |
| (long)tb->tc_ptr, (long)tb->pc, |
| lookup_symbol((void *)tb->pc)); |
| } |
| #endif |
| /* execute the generated code */ |
| tc_ptr = tb->tc_ptr; |
| gen_func = (void *)tc_ptr; |
| gen_func(); |
| } |
| } |
| ret = env->exception_index; |
| |
| /* restore flags in standard format */ |
| env->eflags = env->eflags | cc_table[CC_OP].compute_all() | (DF & DF_MASK); |
| |
| /* restore global registers */ |
| #ifdef reg_EAX |
| EAX = saved_EAX; |
| #endif |
| #ifdef reg_ECX |
| ECX = saved_ECX; |
| #endif |
| #ifdef reg_EDX |
| EDX = saved_EDX; |
| #endif |
| #ifdef reg_EBX |
| EBX = saved_EBX; |
| #endif |
| #ifdef reg_ESP |
| ESP = saved_ESP; |
| #endif |
| #ifdef reg_EBP |
| EBP = saved_EBP; |
| #endif |
| #ifdef reg_ESI |
| ESI = saved_ESI; |
| #endif |
| #ifdef reg_EDI |
| EDI = saved_EDI; |
| #endif |
| T0 = saved_T0; |
| T1 = saved_T1; |
| A0 = saved_A0; |
| env = saved_env; |
| return ret; |
| } |
| |
| void cpu_x86_interrupt(CPUX86State *s) |
| { |
| s->interrupt_request = 1; |
| } |
| |
| |
| void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector) |
| { |
| CPUX86State *saved_env; |
| |
| saved_env = env; |
| env = s; |
| load_seg(seg_reg, selector); |
| env = saved_env; |
| } |
| |
| #undef EAX |
| #undef ECX |
| #undef EDX |
| #undef EBX |
| #undef ESP |
| #undef EBP |
| #undef ESI |
| #undef EDI |
| #undef EIP |
| #include <signal.h> |
| #include <sys/ucontext.h> |
| |
| /* 'pc' is the host PC at which the exception was raised. 'address' is |
| the effective address of the memory exception */ |
| static inline int handle_cpu_signal(unsigned long pc, |
| unsigned long address, |
| sigset_t *old_set) |
| { |
| #ifdef DEBUG_SIGNAL |
| printf("gemu: SIGSEGV pc=0x%08lx oldset=0x%08lx\n", |
| pc, *(unsigned long *)old_set); |
| #endif |
| if (pc >= (unsigned long)code_gen_buffer && |
| pc < (unsigned long)code_gen_buffer + CODE_GEN_BUFFER_SIZE) { |
| /* the PC is inside the translated code. It means that we have |
| a virtual CPU fault */ |
| /* we restore the process signal mask as the sigreturn should |
| do it */ |
| sigprocmask(SIG_SETMASK, old_set, NULL); |
| /* XXX: need to compute virtual pc position by retranslating |
| code. The rest of the CPU state should be correct. */ |
| env->cr2 = address; |
| /* XXX: more precise exception code */ |
| raise_exception_err(EXCP0E_PAGE, 4); |
| /* never comes here */ |
| return 1; |
| } else { |
| return 0; |
| } |
| } |
| |
| int cpu_x86_signal_handler(int host_signum, struct siginfo *info, |
| void *puc) |
| { |
| #if defined(__i386__) |
| struct ucontext *uc = puc; |
| unsigned long pc; |
| sigset_t *pold_set; |
| |
| #ifndef REG_EIP |
| /* for glibc 2.1 */ |
| #define REG_EIP EIP |
| #endif |
| pc = uc->uc_mcontext.gregs[REG_EIP]; |
| pold_set = &uc->uc_sigmask; |
| return handle_cpu_signal(pc, (unsigned long)info->si_addr, pold_set); |
| #else |
| #warning No CPU specific signal handler: cannot handle target SIGSEGV events |
| return 0; |
| #endif |
| } |
