linux-user/qemu.h

   1 #ifndef QEMU_H
   2 #define QEMU_H
   3
   4 #include "hostdep.h"
   5 #include "cpu.h"
   6 #include "exec/exec-all.h"
   7 #include "exec/cpu_ldst.h"
   8
   9 #undef DEBUG_REMAP
  10 #ifdef DEBUG_REMAP
  11 #endif /* DEBUG_REMAP */
  12
  13 #include "exec/user/abitypes.h"
  14
  15 #include "exec/user/thunk.h"
  16 #include "syscall_defs.h"
  17 #include "target_syscall.h"
  18 #include "exec/gdbstub.h"
  19 #include "qemu/queue.h"
  20
  21 #define THREAD __thread
  22
  23 /* This struct is used to hold certain information about the image.
  24  * Basically, it replicates in user space what would be certain
  25  * task_struct fields in the kernel
  26  */
  27 struct image_info {
  28         abi_ulong       load_bias;
  29         abi_ulong       load_addr;
  30         abi_ulong       start_code;
  31         abi_ulong       end_code;
  32         abi_ulong       start_data;
  33         abi_ulong       end_data;
  34         abi_ulong       start_brk;
  35         abi_ulong       brk;
  36         abi_ulong       start_mmap;
  37         abi_ulong       start_stack;
  38         abi_ulong       stack_limit;
  39         abi_ulong       entry;
  40         abi_ulong       code_offset;
  41         abi_ulong       data_offset;
  42         abi_ulong       saved_auxv;
  43         abi_ulong       auxv_len;
  44         abi_ulong       arg_start;
  45         abi_ulong       arg_end;
  46         uint32_t        elf_flags;
  47         int             personality;
  48 #ifdef CONFIG_USE_FDPIC
  49         abi_ulong       loadmap_addr;
  50         uint16_t        nsegs;
  51         void           *loadsegs;
  52         abi_ulong       pt_dynamic_addr;
  53         struct image_info *other_info;
  54 #endif
  55 };
  56
  57 #ifdef TARGET_I386
  58 /* Information about the current linux thread */
  59 struct vm86_saved_state {
  60     uint32_t eax; /* return code */
  61     uint32_t ebx;
  62     uint32_t ecx;
  63     uint32_t edx;
  64     uint32_t esi;
  65     uint32_t edi;
  66     uint32_t ebp;
  67     uint32_t esp;
  68     uint32_t eflags;
  69     uint32_t eip;
  70     uint16_t cs, ss, ds, es, fs, gs;
  71 };
  72 #endif
  73
  74 #if defined(TARGET_ARM) && defined(TARGET_ABI32)
  75 /* FPU emulator */
  76 #include "nwfpe/fpa11.h"
  77 #endif
  78
  79 #define MAX_SIGQUEUE_SIZE 1024
  80
  81 struct emulated_sigtable {
  82     int pending; /* true if signal is pending */
  83     target_siginfo_t info;
  84 };
  85
  86 /* NOTE: we force a big alignment so that the stack stored after is
  87    aligned too */
  88 typedef struct TaskState {
  89     pid_t ts_tid;     /* tid (or pid) of this task */
  90 #ifdef TARGET_ARM
  91 # ifdef TARGET_ABI32
  92     /* FPA state */
  93     FPA11 fpa;
  94 # endif
  95     int swi_errno;
  96 #endif
  97 #ifdef TARGET_UNICORE32
  98     int swi_errno;
  99 #endif
 100 #if defined(TARGET_I386) && !defined(TARGET_X86_64)
 101     abi_ulong target_v86;
 102     struct vm86_saved_state vm86_saved_regs;
 103     struct target_vm86plus_struct vm86plus;
 104     uint32_t v86flags;
 105     uint32_t v86mask;
 106 #endif
 107     abi_ulong child_tidptr;
 108 #ifdef TARGET_M68K
 109     int sim_syscalls;
 110     abi_ulong tp_value;
 111 #endif
 112 #if defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_UNICORE32)
 113     /* Extra fields for semihosted binaries.  */
 114     uint32_t heap_base;
 115     uint32_t heap_limit;
 116 #endif
 117     uint32_t stack_base;
 118     int used; /* non zero if used */
 119     struct image_info *info;
 120     struct linux_binprm *bprm;
 121
 122     struct emulated_sigtable sync_signal;
 123     struct emulated_sigtable sigtab[TARGET_NSIG];
 124     /* This thread's signal mask, as requested by the guest program.
 125      * The actual signal mask of this thread may differ:
 126      *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
 127      *  + sometimes we block all signals to avoid races
 128      */
 129     sigset_t signal_mask;
 130     /* The signal mask imposed by a guest sigsuspend syscall, if we are
 131      * currently in the middle of such a syscall
 132      */
 133     sigset_t sigsuspend_mask;
 134     /* Nonzero if we're leaving a sigsuspend and sigsuspend_mask is valid. */
 135     int in_sigsuspend;
 136
 137     /* Nonzero if process_pending_signals() needs to do something (either
 138      * handle a pending signal or unblock signals).
 139      * This flag is written from a signal handler so should be accessed via
 140      * the atomic_read() and atomic_write() functions. (It is not accessed
 141      * from multiple threads.)
 142      */
 143     int signal_pending;
 144
 145 } __attribute__((aligned(16))) TaskState;
 146
 147 extern char *exec_path;
 148 void init_task_state(TaskState *ts);
 149 void task_settid(TaskState *);
 150 void stop_all_tasks(void);
 151 extern const char *qemu_uname_release;
 152 extern unsigned long mmap_min_addr;
 153
 154 /* ??? See if we can avoid exposing so much of the loader internals.  */
 155
 156 /* Read a good amount of data initially, to hopefully get all the
 157    program headers loaded.  */
 158 #define BPRM_BUF_SIZE  1024
 159
 160 /*
 161  * This structure is used to hold the arguments that are
 162  * used when loading binaries.
 163  */
 164 struct linux_binprm {
 165         char buf[BPRM_BUF_SIZE] __attribute__((aligned));
 166         abi_ulong p;
 167         int fd;
 168         int e_uid, e_gid;
 169         int argc, envc;
 170         char **argv;
 171         char **envp;
 172         char * filename;        /* Name of binary */
 173         int (*core_dump)(int, const CPUArchState *); /* coredump routine */
 174 };
 175
 176 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
 177 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
 178                               abi_ulong stringp, int push_ptr);
 179 int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
 180              struct target_pt_regs * regs, struct image_info *infop,
 181              struct linux_binprm *);
 182
 183 int load_elf_binary(struct linux_binprm *bprm, struct image_info *info);
 184 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info);
 185
 186 abi_long memcpy_to_target(abi_ulong dest, const void *src,
 187                           unsigned long len);
 188 void target_set_brk(abi_ulong new_brk);
 189 abi_long do_brk(abi_ulong new_brk);
 190 void syscall_init(void);
 191 abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
 192                     abi_long arg2, abi_long arg3, abi_long arg4,
 193                     abi_long arg5, abi_long arg6, abi_long arg7,
 194                     abi_long arg8);
 195 void gemu_log(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
 196 extern THREAD CPUState *thread_cpu;
 197 void cpu_loop(CPUArchState *env);
 198 const char *target_strerror(int err);
 199 int get_osversion(void);
 200 void init_qemu_uname_release(void);
 201 void fork_start(void);
 202 void fork_end(int child);
 203
 204 /* Creates the initial guest address space in the host memory space using
 205  * the given host start address hint and size.  The guest_start parameter
 206  * specifies the start address of the guest space.  guest_base will be the
 207  * difference between the host start address computed by this function and
 208  * guest_start.  If fixed is specified, then the mapped address space must
 209  * start at host_start.  The real start address of the mapped memory space is
 210  * returned or -1 if there was an error.
 211  */
 212 unsigned long init_guest_space(unsigned long host_start,
 213                                unsigned long host_size,
 214                                unsigned long guest_start,
 215                                bool fixed);
 216
 217 #include "qemu/log.h"
 218
 219 /* safe_syscall.S */
 220
 221 /**
 222  * safe_syscall:
 223  * @int number: number of system call to make
 224  * ...: arguments to the system call
 225  *
 226  * Call a system call if guest signal not pending.
 227  * This has the same API as the libc syscall() function, except that it
 228  * may return -1 with errno == TARGET_ERESTARTSYS if a signal was pending.
 229  *
 230  * Returns: the system call result, or -1 with an error code in errno
 231  * (Errnos are host errnos; we rely on TARGET_ERESTARTSYS not clashing
 232  * with any of the host errno values.)
 233  */
 234
 235 /* A guide to using safe_syscall() to handle interactions between guest
 236  * syscalls and guest signals:
 237  *
 238  * Guest syscalls come in two flavours:
 239  *
 240  * (1) Non-interruptible syscalls
 241  *
 242  * These are guest syscalls that never get interrupted by signals and
 243  * so never return EINTR. They can be implemented straightforwardly in
 244  * QEMU: just make sure that if the implementation code has to make any
 245  * blocking calls that those calls are retried if they return EINTR.
 246  * It's also OK to implement these with safe_syscall, though it will be
 247  * a little less efficient if a signal is delivered at the 'wrong' moment.
 248  *
 249  * Some non-interruptible syscalls need to be handled using block_signals()
 250  * to block signals for the duration of the syscall. This mainly applies
 251  * to code which needs to modify the data structures used by the
 252  * host_signal_handler() function and the functions it calls, including
 253  * all syscalls which change the thread's signal mask.
 254  *
 255  * (2) Interruptible syscalls
 256  *
 257  * These are guest syscalls that can be interrupted by signals and
 258  * for which we need to either return EINTR or arrange for the guest
 259  * syscall to be restarted. This category includes both syscalls which
 260  * always restart (and in the kernel return -ERESTARTNOINTR), ones
 261  * which only restart if there is no handler (kernel returns -ERESTARTNOHAND
 262  * or -ERESTART_RESTARTBLOCK), and the most common kind which restart
 263  * if the handler was registered with SA_RESTART (kernel returns
 264  * -ERESTARTSYS). System calls which are only interruptible in some
 265  * situations (like 'open') also need to be handled this way.
 266  *
 267  * Here it is important that the host syscall is made
 268  * via this safe_syscall() function, and *not* via the host libc.
 269  * If the host libc is used then the implementation will appear to work
 270  * most of the time, but there will be a race condition where a
 271  * signal could arrive just before we make the host syscall inside libc,
 272  * and then then guest syscall will not correctly be interrupted.
 273  * Instead the implementation of the guest syscall can use the safe_syscall
 274  * function but otherwise just return the result or errno in the usual
 275  * way; the main loop code will take care of restarting the syscall
 276  * if appropriate.
 277  *
 278  * (If the implementation needs to make multiple host syscalls this is
 279  * OK; any which might really block must be via safe_syscall(); for those
 280  * which are only technically blocking (ie which we know in practice won't
 281  * stay in the host kernel indefinitely) it's OK to use libc if necessary.
 282  * You must be able to cope with backing out correctly if some safe_syscall
 283  * you make in the implementation returns either -TARGET_ERESTARTSYS or
 284  * EINTR though.)
 285  *
 286  * block_signals() cannot be used for interruptible syscalls.
 287  *
 288  *
 289  * How and why the safe_syscall implementation works:
 290  *
 291  * The basic setup is that we make the host syscall via a known
 292  * section of host native assembly. If a signal occurs, our signal
 293  * handler checks the interrupted host PC against the addresse of that
 294  * known section. If the PC is before or at the address of the syscall
 295  * instruction then we change the PC to point at a "return
 296  * -TARGET_ERESTARTSYS" code path instead, and then exit the signal handler
 297  * (causing the safe_syscall() call to immediately return that value).
 298  * Then in the main.c loop if we see this magic return value we adjust
 299  * the guest PC to wind it back to before the system call, and invoke
 300  * the guest signal handler as usual.
 301  *
 302  * This winding-back will happen in two cases:
 303  * (1) signal came in just before we took the host syscall (a race);
 304  *   in this case we'll take the guest signal and have another go
 305  *   at the syscall afterwards, and this is indistinguishable for the
 306  *   guest from the timing having been different such that the guest
 307  *   signal really did win the race
 308  * (2) signal came in while the host syscall was blocking, and the
 309  *   host kernel decided the syscall should be restarted;
 310  *   in this case we want to restart the guest syscall also, and so
 311  *   rewinding is the right thing. (Note that "restart" semantics mean
 312  *   "first call the signal handler, then reattempt the syscall".)
 313  * The other situation to consider is when a signal came in while the
 314  * host syscall was blocking, and the host kernel decided that the syscall
 315  * should not be restarted; in this case QEMU's host signal handler will
 316  * be invoked with the PC pointing just after the syscall instruction,
 317  * with registers indicating an EINTR return; the special code in the
 318  * handler will not kick in, and we will return EINTR to the guest as
 319  * we should.
 320  *
 321  * Notice that we can leave the host kernel to make the decision for
 322  * us about whether to do a restart of the syscall or not; we do not
 323  * need to check SA_RESTART flags in QEMU or distinguish the various
 324  * kinds of restartability.
 325  */
 326 #ifdef HAVE_SAFE_SYSCALL
 327 /* The core part of this function is implemented in assembly */
 328 extern long safe_syscall_base(int *pending, long number, ...);
 329
 330 #define safe_syscall(...)                                               \
 331     ({                                                                  \
 332         long ret_;                                                      \
 333         int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \
 334         ret_ = safe_syscall_base(psp_, __VA_ARGS__);                    \
 335         if (is_error(ret_)) {                                           \
 336             errno = -ret_;                                              \
 337             ret_ = -1;                                                  \
 338         }                                                               \
 339         ret_;                                                           \
 340     })
 341
 342 #else
 343
 344 /* Fallback for architectures which don't yet provide a safe-syscall assembly
 345  * fragment; note that this is racy!
 346  * This should go away when all host architectures have been updated.
 347  */
 348 #define safe_syscall syscall
 349
 350 #endif
 351
 352 /* syscall.c */
 353 int host_to_target_waitstatus(int status);
 354
 355 /* strace.c */
 356 void print_syscall(int num,
 357                    abi_long arg1, abi_long arg2, abi_long arg3,
 358                    abi_long arg4, abi_long arg5, abi_long arg6);
 359 void print_syscall_ret(int num, abi_long arg1);
 360 extern int do_strace;
 361
 362 /* signal.c */
 363 void process_pending_signals(CPUArchState *cpu_env);
 364 void signal_init(void);
 365 int queue_signal(CPUArchState *env, int sig, target_siginfo_t *info);
 366 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info);
 367 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo);
 368 int target_to_host_signal(int sig);
 369 int host_to_target_signal(int sig);
 370 long do_sigreturn(CPUArchState *env);
 371 long do_rt_sigreturn(CPUArchState *env);
 372 abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp);
 373 int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset);
 374 /**
 375  * block_signals: block all signals while handling this guest syscall
 376  *
 377  * Block all signals, and arrange that the signal mask is returned to
 378  * its correct value for the guest before we resume execution of guest code.
 379  * If this function returns non-zero, then the caller should immediately
 380  * return -TARGET_ERESTARTSYS to the main loop, which will take the pending
 381  * signal and restart execution of the syscall.
 382  * If block_signals() returns zero, then the caller can continue with
 383  * emulation of the system call knowing that no signals can be taken
 384  * (and therefore that no race conditions will result).
 385  * This should only be called once, because if it is called a second time
 386  * it will always return non-zero. (Think of it like a mutex that can't
 387  * be recursively locked.)
 388  * Signals will be unblocked again by process_pending_signals().
 389  *
 390  * Return value: non-zero if there was a pending signal, zero if not.
 391  */
 392 int block_signals(void); /* Returns non zero if signal pending */
 393
 394 #ifdef TARGET_I386
 395 /* vm86.c */
 396 void save_v86_state(CPUX86State *env);
 397 void handle_vm86_trap(CPUX86State *env, int trapno);
 398 void handle_vm86_fault(CPUX86State *env);
 399 int do_vm86(CPUX86State *env, long subfunction, abi_ulong v86_addr);
 400 #elif defined(TARGET_SPARC64)
 401 void sparc64_set_context(CPUSPARCState *env);
 402 void sparc64_get_context(CPUSPARCState *env);
 403 #endif
 404
 405 /* mmap.c */
 406 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
 407 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
 408                      int flags, int fd, abi_ulong offset);
 409 int target_munmap(abi_ulong start, abi_ulong len);
 410 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
 411                        abi_ulong new_size, unsigned long flags,
 412                        abi_ulong new_addr);
 413 int target_msync(abi_ulong start, abi_ulong len, int flags);
 414 extern unsigned long last_brk;
 415 extern abi_ulong mmap_next_start;
 416 abi_ulong mmap_find_vma(abi_ulong, abi_ulong);
 417 void cpu_list_lock(void);
 418 void cpu_list_unlock(void);
 419 void mmap_fork_start(void);
 420 void mmap_fork_end(int child);
 421
 422 /* main.c */
 423 extern unsigned long guest_stack_size;
 424
 425 /* user access */
 426
 427 #define VERIFY_READ 0
 428 #define VERIFY_WRITE 1 /* implies read access */
 429
 430 static inline int access_ok(int type, abi_ulong addr, abi_ulong size)
 431 {
 432     return page_check_range((target_ulong)addr, size,
 433                             (type == VERIFY_READ) ? PAGE_READ : (PAGE_READ | PAGE_WRITE)) == 0;
 434 }
 435
 436 /* NOTE __get_user and __put_user use host pointers and don't check access.
 437    These are usually used to access struct data members once the struct has
 438    been locked - usually with lock_user_struct.  */
 439
 440 /* Tricky points:
 441    - Use __builtin_choose_expr to avoid type promotion from ?:,
 442    - Invalid sizes result in a compile time error stemming from
 443      the fact that abort has no parameters.
 444    - It's easier to use the endian-specific unaligned load/store
 445      functions than host-endian unaligned load/store plus tswapN.  */
 446
 447 #define __put_user_e(x, hptr, e)                                        \
 448   (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                   \
 449    __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,             \
 450    __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,             \
 451    __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))   \
 452      ((hptr), (x)), (void)0)
 453
 454 #define __get_user_e(x, hptr, e)                                        \
 455   ((x) = (typeof(*hptr))(                                               \
 456    __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                  \
 457    __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,            \
 458    __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,             \
 459    __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))   \
 460      (hptr)), (void)0)
 461
 462 #ifdef TARGET_WORDS_BIGENDIAN
 463 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
 464 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
 465 #else
 466 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
 467 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
 468 #endif
 469
 470 /* put_user()/get_user() take a guest address and check access */
 471 /* These are usually used to access an atomic data type, such as an int,
 472  * that has been passed by address.  These internally perform locking
 473  * and unlocking on the data type.
 474  */
 475 #define put_user(x, gaddr, target_type)                                 \
 476 ({                                                                      \
 477     abi_ulong __gaddr = (gaddr);                                        \
 478     target_type *__hptr;                                                \
 479     abi_long __ret = 0;                                                 \
 480     if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
 481         __put_user((x), __hptr);                                \
 482         unlock_user(__hptr, __gaddr, sizeof(target_type));              \
 483     } else                                                              \
 484         __ret = -TARGET_EFAULT;                                         \
 485     __ret;                                                              \
 486 })
 487
 488 #define get_user(x, gaddr, target_type)                                 \
 489 ({                                                                      \
 490     abi_ulong __gaddr = (gaddr);                                        \
 491     target_type *__hptr;                                                \
 492     abi_long __ret = 0;                                                 \
 493     if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
 494         __get_user((x), __hptr);                                \
 495         unlock_user(__hptr, __gaddr, 0);                                \
 496     } else {                                                            \
 497         /* avoid warning */                                             \
 498         (x) = 0;                                                        \
 499         __ret = -TARGET_EFAULT;                                         \
 500     }                                                                   \
 501     __ret;                                                              \
 502 })
 503
 504 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
 505 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
 506 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
 507 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
 508 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
 509 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
 510 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
 511 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
 512 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
 513 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
 514
 515 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
 516 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
 517 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
 518 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
 519 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
 520 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
 521 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
 522 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
 523 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
 524 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
 525
 526 /* copy_from_user() and copy_to_user() are usually used to copy data
 527  * buffers between the target and host.  These internally perform
 528  * locking/unlocking of the memory.
 529  */
 530 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
 531 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
 532
 533 /* Functions for accessing guest memory.  The tget and tput functions
 534    read/write single values, byteswapping as necessary.  The lock_user function
 535    gets a pointer to a contiguous area of guest memory, but does not perform
 536    any byteswapping.  lock_user may return either a pointer to the guest
 537    memory, or a temporary buffer.  */
 538
 539 /* Lock an area of guest memory into the host.  If copy is true then the
 540    host area will have the same contents as the guest.  */
 541 static inline void *lock_user(int type, abi_ulong guest_addr, long len, int copy)
 542 {
 543     if (!access_ok(type, guest_addr, len))
 544         return NULL;
 545 #ifdef DEBUG_REMAP
 546     {
 547         void *addr;
 548         addr = malloc(len);
 549         if (copy)
 550             memcpy(addr, g2h(guest_addr), len);
 551         else
 552             memset(addr, 0, len);
 553         return addr;
 554     }
 555 #else
 556     return g2h(guest_addr);
 557 #endif
 558 }
 559
 560 /* Unlock an area of guest memory.  The first LEN bytes must be
 561    flushed back to guest memory. host_ptr = NULL is explicitly
 562    allowed and does nothing. */
 563 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
 564                                long len)
 565 {
 566
 567 #ifdef DEBUG_REMAP
 568     if (!host_ptr)
 569         return;
 570     if (host_ptr == g2h(guest_addr))
 571         return;
 572     if (len > 0)
 573         memcpy(g2h(guest_addr), host_ptr, len);
 574     free(host_ptr);
 575 #endif
 576 }
 577
 578 /* Return the length of a string in target memory or -TARGET_EFAULT if
 579    access error. */
 580 abi_long target_strlen(abi_ulong gaddr);
 581
 582 /* Like lock_user but for null terminated strings.  */
 583 static inline void *lock_user_string(abi_ulong guest_addr)
 584 {
 585     abi_long len;
 586     len = target_strlen(guest_addr);
 587     if (len < 0)
 588         return NULL;
 589     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
 590 }
 591
 592 /* Helper macros for locking/unlocking a target struct.  */
 593 #define lock_user_struct(type, host_ptr, guest_addr, copy)      \
 594     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
 595 #define unlock_user_struct(host_ptr, guest_addr, copy)          \
 596     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
 597
 598 #include <pthread.h>
 599
 600 /* Include target-specific struct and function definitions;
 601  * they may need access to the target-independent structures
 602  * above, so include them last.
 603  */
 604 #include "target_cpu.h"
 605 #include "target_signal.h"
 606 #include "target_structs.h"
 607
 608 #endif /* QEMU_H */