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 is the size of the host kernel's sigset_t, needed where we make
  24  * direct system calls that take a sigset_t pointer and a size.
  25  */
  26 #define SIGSET_T_SIZE (_NSIG / 8)
  27
  28 /* This struct is used to hold certain information about the image.
  29  * Basically, it replicates in user space what would be certain
  30  * task_struct fields in the kernel
  31  */
  32 struct image_info {
  33         abi_ulong       load_bias;
  34         abi_ulong       load_addr;
  35         abi_ulong       start_code;
  36         abi_ulong       end_code;
  37         abi_ulong       start_data;
  38         abi_ulong       end_data;
  39         abi_ulong       start_brk;
  40         abi_ulong       brk;
  41         abi_ulong       start_mmap;
  42         abi_ulong       start_stack;
  43         abi_ulong       stack_limit;
  44         abi_ulong       entry;
  45         abi_ulong       code_offset;
  46         abi_ulong       data_offset;
  47         abi_ulong       saved_auxv;
  48         abi_ulong       auxv_len;
  49         abi_ulong       arg_start;
  50         abi_ulong       arg_end;
  51         uint32_t        elf_flags;
  52         int             personality;
  53 #ifdef CONFIG_USE_FDPIC
  54         abi_ulong       loadmap_addr;
  55         uint16_t        nsegs;
  56         void           *loadsegs;
  57         abi_ulong       pt_dynamic_addr;
  58         struct image_info *other_info;
  59 #endif
  60 };
  61
  62 #ifdef TARGET_I386
  63 /* Information about the current linux thread */
  64 struct vm86_saved_state {
  65     uint32_t eax; /* return code */
  66     uint32_t ebx;
  67     uint32_t ecx;
  68     uint32_t edx;
  69     uint32_t esi;
  70     uint32_t edi;
  71     uint32_t ebp;
  72     uint32_t esp;
  73     uint32_t eflags;
  74     uint32_t eip;
  75     uint16_t cs, ss, ds, es, fs, gs;
  76 };
  77 #endif
  78
  79 #if defined(TARGET_ARM) && defined(TARGET_ABI32)
  80 /* FPU emulator */
  81 #include "nwfpe/fpa11.h"
  82 #endif
  83
  84 #define MAX_SIGQUEUE_SIZE 1024
  85
  86 struct emulated_sigtable {
  87     int pending; /* true if signal is pending */
  88     target_siginfo_t info;
  89 };
  90
  91 /* NOTE: we force a big alignment so that the stack stored after is
  92    aligned too */
  93 typedef struct TaskState {
  94     pid_t ts_tid;     /* tid (or pid) of this task */
  95 #ifdef TARGET_ARM
  96 # ifdef TARGET_ABI32
  97     /* FPA state */
  98     FPA11 fpa;
  99 # endif
 100     int swi_errno;
 101 #endif
 102 #ifdef TARGET_UNICORE32
 103     int swi_errno;
 104 #endif
 105 #if defined(TARGET_I386) && !defined(TARGET_X86_64)
 106     abi_ulong target_v86;
 107     struct vm86_saved_state vm86_saved_regs;
 108     struct target_vm86plus_struct vm86plus;
 109     uint32_t v86flags;
 110     uint32_t v86mask;
 111 #endif
 112     abi_ulong child_tidptr;
 113 #ifdef TARGET_M68K
 114     int sim_syscalls;
 115     abi_ulong tp_value;
 116 #endif
 117 #if defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_UNICORE32)
 118     /* Extra fields for semihosted binaries.  */
 119     abi_ulong heap_base;
 120     abi_ulong heap_limit;
 121 #endif
 122     abi_ulong stack_base;
 123     int used; /* non zero if used */
 124     struct image_info *info;
 125     struct linux_binprm *bprm;
 126
 127     struct emulated_sigtable sync_signal;
 128     struct emulated_sigtable sigtab[TARGET_NSIG];
 129     /* This thread's signal mask, as requested by the guest program.
 130      * The actual signal mask of this thread may differ:
 131      *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
 132      *  + sometimes we block all signals to avoid races
 133      */
 134     sigset_t signal_mask;
 135     /* The signal mask imposed by a guest sigsuspend syscall, if we are
 136      * currently in the middle of such a syscall
 137      */
 138     sigset_t sigsuspend_mask;
 139     /* Nonzero if we're leaving a sigsuspend and sigsuspend_mask is valid. */
 140     int in_sigsuspend;
 141
 142     /* Nonzero if process_pending_signals() needs to do something (either
 143      * handle a pending signal or unblock signals).
 144      * This flag is written from a signal handler so should be accessed via
 145      * the atomic_read() and atomic_write() functions. (It is not accessed
 146      * from multiple threads.)
 147      */
 148     int signal_pending;
 149
 150 } __attribute__((aligned(16))) TaskState;
 151
 152 extern char *exec_path;
 153 void init_task_state(TaskState *ts);
 154 void task_settid(TaskState *);
 155 void stop_all_tasks(void);
 156 extern const char *qemu_uname_release;
 157 extern unsigned long mmap_min_addr;
 158
 159 /* ??? See if we can avoid exposing so much of the loader internals.  */
 160
 161 /* Read a good amount of data initially, to hopefully get all the
 162    program headers loaded.  */
 163 #define BPRM_BUF_SIZE  1024
 164
 165 /*
 166  * This structure is used to hold the arguments that are
 167  * used when loading binaries.
 168  */
 169 struct linux_binprm {
 170         char buf[BPRM_BUF_SIZE] __attribute__((aligned));
 171         abi_ulong p;
 172         int fd;
 173         int e_uid, e_gid;
 174         int argc, envc;
 175         char **argv;
 176         char **envp;
 177         char * filename;        /* Name of binary */
 178         int (*core_dump)(int, const CPUArchState *); /* coredump routine */
 179 };
 180
 181 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
 182 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
 183                               abi_ulong stringp, int push_ptr);
 184 int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
 185              struct target_pt_regs * regs, struct image_info *infop,
 186              struct linux_binprm *);
 187
 188 int load_elf_binary(struct linux_binprm *bprm, struct image_info *info);
 189 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info);
 190
 191 abi_long memcpy_to_target(abi_ulong dest, const void *src,
 192                           unsigned long len);
 193 void target_set_brk(abi_ulong new_brk);
 194 abi_long do_brk(abi_ulong new_brk);
 195 void syscall_init(void);
 196 abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
 197                     abi_long arg2, abi_long arg3, abi_long arg4,
 198                     abi_long arg5, abi_long arg6, abi_long arg7,
 199                     abi_long arg8);
 200 void gemu_log(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
 201 extern THREAD CPUState *thread_cpu;
 202 void cpu_loop(CPUArchState *env);
 203 const char *target_strerror(int err);
 204 int get_osversion(void);
 205 void init_qemu_uname_release(void);
 206 void fork_start(void);
 207 void fork_end(int child);
 208
 209 /* Creates the initial guest address space in the host memory space using
 210  * the given host start address hint and size.  The guest_start parameter
 211  * specifies the start address of the guest space.  guest_base will be the
 212  * difference between the host start address computed by this function and
 213  * guest_start.  If fixed is specified, then the mapped address space must
 214  * start at host_start.  The real start address of the mapped memory space is
 215  * returned or -1 if there was an error.
 216  */
 217 unsigned long init_guest_space(unsigned long host_start,
 218                                unsigned long host_size,
 219                                unsigned long guest_start,
 220                                bool fixed);
 221
 222 #include "qemu/log.h"
 223
 224 /* safe_syscall.S */
 225
 226 /**
 227  * safe_syscall:
 228  * @int number: number of system call to make
 229  * ...: arguments to the system call
 230  *
 231  * Call a system call if guest signal not pending.
 232  * This has the same API as the libc syscall() function, except that it
 233  * may return -1 with errno == TARGET_ERESTARTSYS if a signal was pending.
 234  *
 235  * Returns: the system call result, or -1 with an error code in errno
 236  * (Errnos are host errnos; we rely on TARGET_ERESTARTSYS not clashing
 237  * with any of the host errno values.)
 238  */
 239
 240 /* A guide to using safe_syscall() to handle interactions between guest
 241  * syscalls and guest signals:
 242  *
 243  * Guest syscalls come in two flavours:
 244  *
 245  * (1) Non-interruptible syscalls
 246  *
 247  * These are guest syscalls that never get interrupted by signals and
 248  * so never return EINTR. They can be implemented straightforwardly in
 249  * QEMU: just make sure that if the implementation code has to make any
 250  * blocking calls that those calls are retried if they return EINTR.
 251  * It's also OK to implement these with safe_syscall, though it will be
 252  * a little less efficient if a signal is delivered at the 'wrong' moment.
 253  *
 254  * Some non-interruptible syscalls need to be handled using block_signals()
 255  * to block signals for the duration of the syscall. This mainly applies
 256  * to code which needs to modify the data structures used by the
 257  * host_signal_handler() function and the functions it calls, including
 258  * all syscalls which change the thread's signal mask.
 259  *
 260  * (2) Interruptible syscalls
 261  *
 262  * These are guest syscalls that can be interrupted by signals and
 263  * for which we need to either return EINTR or arrange for the guest
 264  * syscall to be restarted. This category includes both syscalls which
 265  * always restart (and in the kernel return -ERESTARTNOINTR), ones
 266  * which only restart if there is no handler (kernel returns -ERESTARTNOHAND
 267  * or -ERESTART_RESTARTBLOCK), and the most common kind which restart
 268  * if the handler was registered with SA_RESTART (kernel returns
 269  * -ERESTARTSYS). System calls which are only interruptible in some
 270  * situations (like 'open') also need to be handled this way.
 271  *
 272  * Here it is important that the host syscall is made
 273  * via this safe_syscall() function, and *not* via the host libc.
 274  * If the host libc is used then the implementation will appear to work
 275  * most of the time, but there will be a race condition where a
 276  * signal could arrive just before we make the host syscall inside libc,
 277  * and then then guest syscall will not correctly be interrupted.
 278  * Instead the implementation of the guest syscall can use the safe_syscall
 279  * function but otherwise just return the result or errno in the usual
 280  * way; the main loop code will take care of restarting the syscall
 281  * if appropriate.
 282  *
 283  * (If the implementation needs to make multiple host syscalls this is
 284  * OK; any which might really block must be via safe_syscall(); for those
 285  * which are only technically blocking (ie which we know in practice won't
 286  * stay in the host kernel indefinitely) it's OK to use libc if necessary.
 287  * You must be able to cope with backing out correctly if some safe_syscall
 288  * you make in the implementation returns either -TARGET_ERESTARTSYS or
 289  * EINTR though.)
 290  *
 291  * block_signals() cannot be used for interruptible syscalls.
 292  *
 293  *
 294  * How and why the safe_syscall implementation works:
 295  *
 296  * The basic setup is that we make the host syscall via a known
 297  * section of host native assembly. If a signal occurs, our signal
 298  * handler checks the interrupted host PC against the addresse of that
 299  * known section. If the PC is before or at the address of the syscall
 300  * instruction then we change the PC to point at a "return
 301  * -TARGET_ERESTARTSYS" code path instead, and then exit the signal handler
 302  * (causing the safe_syscall() call to immediately return that value).
 303  * Then in the main.c loop if we see this magic return value we adjust
 304  * the guest PC to wind it back to before the system call, and invoke
 305  * the guest signal handler as usual.
 306  *
 307  * This winding-back will happen in two cases:
 308  * (1) signal came in just before we took the host syscall (a race);
 309  *   in this case we'll take the guest signal and have another go
 310  *   at the syscall afterwards, and this is indistinguishable for the
 311  *   guest from the timing having been different such that the guest
 312  *   signal really did win the race
 313  * (2) signal came in while the host syscall was blocking, and the
 314  *   host kernel decided the syscall should be restarted;
 315  *   in this case we want to restart the guest syscall also, and so
 316  *   rewinding is the right thing. (Note that "restart" semantics mean
 317  *   "first call the signal handler, then reattempt the syscall".)
 318  * The other situation to consider is when a signal came in while the
 319  * host syscall was blocking, and the host kernel decided that the syscall
 320  * should not be restarted; in this case QEMU's host signal handler will
 321  * be invoked with the PC pointing just after the syscall instruction,
 322  * with registers indicating an EINTR return; the special code in the
 323  * handler will not kick in, and we will return EINTR to the guest as
 324  * we should.
 325  *
 326  * Notice that we can leave the host kernel to make the decision for
 327  * us about whether to do a restart of the syscall or not; we do not
 328  * need to check SA_RESTART flags in QEMU or distinguish the various
 329  * kinds of restartability.
 330  */
 331 #ifdef HAVE_SAFE_SYSCALL
 332 /* The core part of this function is implemented in assembly */
 333 extern long safe_syscall_base(int *pending, long number, ...);
 334
 335 #define safe_syscall(...)                                               \
 336     ({                                                                  \
 337         long ret_;                                                      \
 338         int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \
 339         ret_ = safe_syscall_base(psp_, __VA_ARGS__);                    \
 340         if (is_error(ret_)) {                                           \
 341             errno = -ret_;                                              \
 342             ret_ = -1;                                                  \
 343         }                                                               \
 344         ret_;                                                           \
 345     })
 346
 347 #else
 348
 349 /* Fallback for architectures which don't yet provide a safe-syscall assembly
 350  * fragment; note that this is racy!
 351  * This should go away when all host architectures have been updated.
 352  */
 353 #define safe_syscall syscall
 354
 355 #endif
 356
 357 /* syscall.c */
 358 int host_to_target_waitstatus(int status);
 359
 360 /* strace.c */
 361 void print_syscall(int num,
 362                    abi_long arg1, abi_long arg2, abi_long arg3,
 363                    abi_long arg4, abi_long arg5, abi_long arg6);
 364 void print_syscall_ret(int num, abi_long arg1);
 365 /**
 366  * print_taken_signal:
 367  * @target_signum: target signal being taken
 368  * @tinfo: target_siginfo_t which will be passed to the guest for the signal
 369  *
 370  * Print strace output indicating that this signal is being taken by the guest,
 371  * in a format similar to:
 372  * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
 373  */
 374 void print_taken_signal(int target_signum, const target_siginfo_t *tinfo);
 375 extern int do_strace;
 376
 377 /* signal.c */
 378 void process_pending_signals(CPUArchState *cpu_env);
 379 void signal_init(void);
 380 int queue_signal(CPUArchState *env, int sig, int si_type,
 381                  target_siginfo_t *info);
 382 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info);
 383 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo);
 384 int target_to_host_signal(int sig);
 385 int host_to_target_signal(int sig);
 386 long do_sigreturn(CPUArchState *env);
 387 long do_rt_sigreturn(CPUArchState *env);
 388 abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp);
 389 int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset);
 390 /**
 391  * block_signals: block all signals while handling this guest syscall
 392  *
 393  * Block all signals, and arrange that the signal mask is returned to
 394  * its correct value for the guest before we resume execution of guest code.
 395  * If this function returns non-zero, then the caller should immediately
 396  * return -TARGET_ERESTARTSYS to the main loop, which will take the pending
 397  * signal and restart execution of the syscall.
 398  * If block_signals() returns zero, then the caller can continue with
 399  * emulation of the system call knowing that no signals can be taken
 400  * (and therefore that no race conditions will result).
 401  * This should only be called once, because if it is called a second time
 402  * it will always return non-zero. (Think of it like a mutex that can't
 403  * be recursively locked.)
 404  * Signals will be unblocked again by process_pending_signals().
 405  *
 406  * Return value: non-zero if there was a pending signal, zero if not.
 407  */
 408 int block_signals(void); /* Returns non zero if signal pending */
 409
 410 #ifdef TARGET_I386
 411 /* vm86.c */
 412 void save_v86_state(CPUX86State *env);
 413 void handle_vm86_trap(CPUX86State *env, int trapno);
 414 void handle_vm86_fault(CPUX86State *env);
 415 int do_vm86(CPUX86State *env, long subfunction, abi_ulong v86_addr);
 416 #elif defined(TARGET_SPARC64)
 417 void sparc64_set_context(CPUSPARCState *env);
 418 void sparc64_get_context(CPUSPARCState *env);
 419 #endif
 420
 421 /* mmap.c */
 422 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
 423 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
 424                      int flags, int fd, abi_ulong offset);
 425 int target_munmap(abi_ulong start, abi_ulong len);
 426 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
 427                        abi_ulong new_size, unsigned long flags,
 428                        abi_ulong new_addr);
 429 int target_msync(abi_ulong start, abi_ulong len, int flags);
 430 extern unsigned long last_brk;
 431 extern abi_ulong mmap_next_start;
 432 abi_ulong mmap_find_vma(abi_ulong, abi_ulong);
 433 void mmap_fork_start(void);
 434 void mmap_fork_end(int child);
 435
 436 /* main.c */
 437 extern unsigned long guest_stack_size;
 438
 439 /* user access */
 440
 441 #define VERIFY_READ 0
 442 #define VERIFY_WRITE 1 /* implies read access */
 443
 444 static inline int access_ok(int type, abi_ulong addr, abi_ulong size)
 445 {
 446     return page_check_range((target_ulong)addr, size,
 447                             (type == VERIFY_READ) ? PAGE_READ : (PAGE_READ | PAGE_WRITE)) == 0;
 448 }
 449
 450 /* NOTE __get_user and __put_user use host pointers and don't check access.
 451    These are usually used to access struct data members once the struct has
 452    been locked - usually with lock_user_struct.  */
 453
 454 /* Tricky points:
 455    - Use __builtin_choose_expr to avoid type promotion from ?:,
 456    - Invalid sizes result in a compile time error stemming from
 457      the fact that abort has no parameters.
 458    - It's easier to use the endian-specific unaligned load/store
 459      functions than host-endian unaligned load/store plus tswapN.  */
 460
 461 #define __put_user_e(x, hptr, e)                                        \
 462   (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                   \
 463    __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,             \
 464    __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,             \
 465    __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))   \
 466      ((hptr), (x)), (void)0)
 467
 468 #define __get_user_e(x, hptr, e)                                        \
 469   ((x) = (typeof(*hptr))(                                               \
 470    __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                  \
 471    __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,            \
 472    __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,             \
 473    __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))   \
 474      (hptr)), (void)0)
 475
 476 #ifdef TARGET_WORDS_BIGENDIAN
 477 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
 478 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
 479 #else
 480 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
 481 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
 482 #endif
 483
 484 /* put_user()/get_user() take a guest address and check access */
 485 /* These are usually used to access an atomic data type, such as an int,
 486  * that has been passed by address.  These internally perform locking
 487  * and unlocking on the data type.
 488  */
 489 #define put_user(x, gaddr, target_type)                                 \
 490 ({                                                                      \
 491     abi_ulong __gaddr = (gaddr);                                        \
 492     target_type *__hptr;                                                \
 493     abi_long __ret = 0;                                                 \
 494     if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
 495         __put_user((x), __hptr);                                \
 496         unlock_user(__hptr, __gaddr, sizeof(target_type));              \
 497     } else                                                              \
 498         __ret = -TARGET_EFAULT;                                         \
 499     __ret;                                                              \
 500 })
 501
 502 #define get_user(x, gaddr, target_type)                                 \
 503 ({                                                                      \
 504     abi_ulong __gaddr = (gaddr);                                        \
 505     target_type *__hptr;                                                \
 506     abi_long __ret = 0;                                                 \
 507     if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
 508         __get_user((x), __hptr);                                \
 509         unlock_user(__hptr, __gaddr, 0);                                \
 510     } else {                                                            \
 511         /* avoid warning */                                             \
 512         (x) = 0;                                                        \
 513         __ret = -TARGET_EFAULT;                                         \
 514     }                                                                   \
 515     __ret;                                                              \
 516 })
 517
 518 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
 519 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
 520 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
 521 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
 522 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
 523 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
 524 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
 525 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
 526 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
 527 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
 528
 529 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
 530 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
 531 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
 532 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
 533 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
 534 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
 535 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
 536 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
 537 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
 538 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
 539
 540 /* copy_from_user() and copy_to_user() are usually used to copy data
 541  * buffers between the target and host.  These internally perform
 542  * locking/unlocking of the memory.
 543  */
 544 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
 545 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
 546
 547 /* Functions for accessing guest memory.  The tget and tput functions
 548    read/write single values, byteswapping as necessary.  The lock_user function
 549    gets a pointer to a contiguous area of guest memory, but does not perform
 550    any byteswapping.  lock_user may return either a pointer to the guest
 551    memory, or a temporary buffer.  */
 552
 553 /* Lock an area of guest memory into the host.  If copy is true then the
 554    host area will have the same contents as the guest.  */
 555 static inline void *lock_user(int type, abi_ulong guest_addr, long len, int copy)
 556 {
 557     if (!access_ok(type, guest_addr, len))
 558         return NULL;
 559 #ifdef DEBUG_REMAP
 560     {
 561         void *addr;
 562         addr = g_malloc(len);
 563         if (copy)
 564             memcpy(addr, g2h(guest_addr), len);
 565         else
 566             memset(addr, 0, len);
 567         return addr;
 568     }
 569 #else
 570     return g2h(guest_addr);
 571 #endif
 572 }
 573
 574 /* Unlock an area of guest memory.  The first LEN bytes must be
 575    flushed back to guest memory. host_ptr = NULL is explicitly
 576    allowed and does nothing. */
 577 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
 578                                long len)
 579 {
 580
 581 #ifdef DEBUG_REMAP
 582     if (!host_ptr)
 583         return;
 584     if (host_ptr == g2h(guest_addr))
 585         return;
 586     if (len > 0)
 587         memcpy(g2h(guest_addr), host_ptr, len);
 588     g_free(host_ptr);
 589 #endif
 590 }
 591
 592 /* Return the length of a string in target memory or -TARGET_EFAULT if
 593    access error. */
 594 abi_long target_strlen(abi_ulong gaddr);
 595
 596 /* Like lock_user but for null terminated strings.  */
 597 static inline void *lock_user_string(abi_ulong guest_addr)
 598 {
 599     abi_long len;
 600     len = target_strlen(guest_addr);
 601     if (len < 0)
 602         return NULL;
 603     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
 604 }
 605
 606 /* Helper macros for locking/unlocking a target struct.  */
 607 #define lock_user_struct(type, host_ptr, guest_addr, copy)      \
 608     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
 609 #define unlock_user_struct(host_ptr, guest_addr, copy)          \
 610     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
 611
 612 #include <pthread.h>
 613
 614 /* Include target-specific struct and function definitions;
 615  * they may need access to the target-independent structures
 616  * above, so include them last.
 617  */
 618 #include "target_cpu.h"
 619 #include "target_signal.h"
 620 #include "target_structs.h"
 621
 622 #endif /* QEMU_H */