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 /* This is the size of the host kernel's sigset_t, needed where we make
  22  * direct system calls that take a sigset_t pointer and a size.
  23  */
  24 #define SIGSET_T_SIZE (_NSIG / 8)
  25
  26 /* This struct is used to hold certain information about the image.
  27  * Basically, it replicates in user space what would be certain
  28  * task_struct fields in the kernel
  29  */
  30 struct image_info {
  31         abi_ulong       load_bias;
  32         abi_ulong       load_addr;
  33         abi_ulong       start_code;
  34         abi_ulong       end_code;
  35         abi_ulong       start_data;
  36         abi_ulong       end_data;
  37         abi_ulong       start_brk;
  38         abi_ulong       brk;
  39         abi_ulong       start_mmap;
  40         abi_ulong       start_stack;
  41         abi_ulong       stack_limit;
  42         abi_ulong       entry;
  43         abi_ulong       code_offset;
  44         abi_ulong       data_offset;
  45         abi_ulong       saved_auxv;
  46         abi_ulong       auxv_len;
  47         abi_ulong       arg_start;
  48         abi_ulong       arg_end;
  49         abi_ulong       arg_strings;
  50         abi_ulong       env_strings;
  51         abi_ulong       file_string;
  52         uint32_t        elf_flags;
  53         int             personality;
  54 #ifdef CONFIG_USE_FDPIC
  55         abi_ulong       loadmap_addr;
  56         uint16_t        nsegs;
  57         void           *loadsegs;
  58         abi_ulong       pt_dynamic_addr;
  59         struct image_info *other_info;
  60 #endif
  61 };
  62
  63 #ifdef TARGET_I386
  64 /* Information about the current linux thread */
  65 struct vm86_saved_state {
  66     uint32_t eax; /* return code */
  67     uint32_t ebx;
  68     uint32_t ecx;
  69     uint32_t edx;
  70     uint32_t esi;
  71     uint32_t edi;
  72     uint32_t ebp;
  73     uint32_t esp;
  74     uint32_t eflags;
  75     uint32_t eip;
  76     uint16_t cs, ss, ds, es, fs, gs;
  77 };
  78 #endif
  79
  80 #if defined(TARGET_ARM) && defined(TARGET_ABI32)
  81 /* FPU emulator */
  82 #include "nwfpe/fpa11.h"
  83 #endif
  84
  85 #define MAX_SIGQUEUE_SIZE 1024
  86
  87 struct emulated_sigtable {
  88     int pending; /* true if signal is pending */
  89     target_siginfo_t info;
  90 };
  91
  92 /* NOTE: we force a big alignment so that the stack stored after is
  93    aligned too */
  94 typedef struct TaskState {
  95     pid_t ts_tid;     /* tid (or pid) of this task */
  96 #ifdef TARGET_ARM
  97 # ifdef TARGET_ABI32
  98     /* FPA state */
  99     FPA11 fpa;
 100 # endif
 101     int swi_errno;
 102 #endif
 103 #ifdef TARGET_UNICORE32
 104     int swi_errno;
 105 #endif
 106 #if defined(TARGET_I386) && !defined(TARGET_X86_64)
 107     abi_ulong target_v86;
 108     struct vm86_saved_state vm86_saved_regs;
 109     struct target_vm86plus_struct vm86plus;
 110     uint32_t v86flags;
 111     uint32_t v86mask;
 112 #endif
 113     abi_ulong child_tidptr;
 114 #ifdef TARGET_M68K
 115     int sim_syscalls;
 116     abi_ulong tp_value;
 117 #endif
 118 #if defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_UNICORE32)
 119     /* Extra fields for semihosted binaries.  */
 120     abi_ulong heap_base;
 121     abi_ulong heap_limit;
 122 #endif
 123     abi_ulong stack_base;
 124     int used; /* non zero if used */
 125     struct image_info *info;
 126     struct linux_binprm *bprm;
 127
 128     struct emulated_sigtable sync_signal;
 129     struct emulated_sigtable sigtab[TARGET_NSIG];
 130     /* This thread's signal mask, as requested by the guest program.
 131      * The actual signal mask of this thread may differ:
 132      *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
 133      *  + sometimes we block all signals to avoid races
 134      */
 135     sigset_t signal_mask;
 136     /* The signal mask imposed by a guest sigsuspend syscall, if we are
 137      * currently in the middle of such a syscall
 138      */
 139     sigset_t sigsuspend_mask;
 140     /* Nonzero if we're leaving a sigsuspend and sigsuspend_mask is valid. */
 141     int in_sigsuspend;
 142
 143     /* Nonzero if process_pending_signals() needs to do something (either
 144      * handle a pending signal or unblock signals).
 145      * This flag is written from a signal handler so should be accessed via
 146      * the atomic_read() and atomic_write() functions. (It is not accessed
 147      * from multiple threads.)
 148      */
 149     int signal_pending;
 150
 151 } __attribute__((aligned(16))) TaskState;
 152
 153 extern char *exec_path;
 154 void init_task_state(TaskState *ts);
 155 void task_settid(TaskState *);
 156 void stop_all_tasks(void);
 157 extern const char *qemu_uname_release;
 158 extern unsigned long mmap_min_addr;
 159
 160 /* ??? See if we can avoid exposing so much of the loader internals.  */
 161
 162 /* Read a good amount of data initially, to hopefully get all the
 163    program headers loaded.  */
 164 #define BPRM_BUF_SIZE  1024
 165
 166 /*
 167  * This structure is used to hold the arguments that are
 168  * used when loading binaries.
 169  */
 170 struct linux_binprm {
 171         char buf[BPRM_BUF_SIZE] __attribute__((aligned));
 172         abi_ulong p;
 173         int fd;
 174         int e_uid, e_gid;
 175         int argc, envc;
 176         char **argv;
 177         char **envp;
 178         char * filename;        /* Name of binary */
 179         int (*core_dump)(int, const CPUArchState *); /* coredump routine */
 180 };
 181
 182 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
 183 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
 184                               abi_ulong stringp, int push_ptr);
 185 int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
 186              struct target_pt_regs * regs, struct image_info *infop,
 187              struct linux_binprm *);
 188
 189 uint32_t get_elf_eflags(int fd);
 190 int load_elf_binary(struct linux_binprm *bprm, struct image_info *info);
 191 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info);
 192
 193 abi_long memcpy_to_target(abi_ulong dest, const void *src,
 194                           unsigned long len);
 195 void target_set_brk(abi_ulong new_brk);
 196 abi_long do_brk(abi_ulong new_brk);
 197 void syscall_init(void);
 198 abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
 199                     abi_long arg2, abi_long arg3, abi_long arg4,
 200                     abi_long arg5, abi_long arg6, abi_long arg7,
 201                     abi_long arg8);
 202 void gemu_log(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
 203 extern __thread CPUState *thread_cpu;
 204 void cpu_loop(CPUArchState *env);
 205 const char *target_strerror(int err);
 206 int get_osversion(void);
 207 void init_qemu_uname_release(void);
 208 void fork_start(void);
 209 void fork_end(int child);
 210
 211 /* Creates the initial guest address space in the host memory space using
 212  * the given host start address hint and size.  The guest_start parameter
 213  * specifies the start address of the guest space.  guest_base will be the
 214  * difference between the host start address computed by this function and
 215  * guest_start.  If fixed is specified, then the mapped address space must
 216  * start at host_start.  The real start address of the mapped memory space is
 217  * returned or -1 if there was an error.
 218  */
 219 unsigned long init_guest_space(unsigned long host_start,
 220                                unsigned long host_size,
 221                                unsigned long guest_start,
 222                                bool fixed);
 223
 224 #include "qemu/log.h"
 225
 226 /* safe_syscall.S */
 227
 228 /**
 229  * safe_syscall:
 230  * @int number: number of system call to make
 231  * ...: arguments to the system call
 232  *
 233  * Call a system call if guest signal not pending.
 234  * This has the same API as the libc syscall() function, except that it
 235  * may return -1 with errno == TARGET_ERESTARTSYS if a signal was pending.
 236  *
 237  * Returns: the system call result, or -1 with an error code in errno
 238  * (Errnos are host errnos; we rely on TARGET_ERESTARTSYS not clashing
 239  * with any of the host errno values.)
 240  */
 241
 242 /* A guide to using safe_syscall() to handle interactions between guest
 243  * syscalls and guest signals:
 244  *
 245  * Guest syscalls come in two flavours:
 246  *
 247  * (1) Non-interruptible syscalls
 248  *
 249  * These are guest syscalls that never get interrupted by signals and
 250  * so never return EINTR. They can be implemented straightforwardly in
 251  * QEMU: just make sure that if the implementation code has to make any
 252  * blocking calls that those calls are retried if they return EINTR.
 253  * It's also OK to implement these with safe_syscall, though it will be
 254  * a little less efficient if a signal is delivered at the 'wrong' moment.
 255  *
 256  * Some non-interruptible syscalls need to be handled using block_signals()
 257  * to block signals for the duration of the syscall. This mainly applies
 258  * to code which needs to modify the data structures used by the
 259  * host_signal_handler() function and the functions it calls, including
 260  * all syscalls which change the thread's signal mask.
 261  *
 262  * (2) Interruptible syscalls
 263  *
 264  * These are guest syscalls that can be interrupted by signals and
 265  * for which we need to either return EINTR or arrange for the guest
 266  * syscall to be restarted. This category includes both syscalls which
 267  * always restart (and in the kernel return -ERESTARTNOINTR), ones
 268  * which only restart if there is no handler (kernel returns -ERESTARTNOHAND
 269  * or -ERESTART_RESTARTBLOCK), and the most common kind which restart
 270  * if the handler was registered with SA_RESTART (kernel returns
 271  * -ERESTARTSYS). System calls which are only interruptible in some
 272  * situations (like 'open') also need to be handled this way.
 273  *
 274  * Here it is important that the host syscall is made
 275  * via this safe_syscall() function, and *not* via the host libc.
 276  * If the host libc is used then the implementation will appear to work
 277  * most of the time, but there will be a race condition where a
 278  * signal could arrive just before we make the host syscall inside libc,
 279  * and then then guest syscall will not correctly be interrupted.
 280  * Instead the implementation of the guest syscall can use the safe_syscall
 281  * function but otherwise just return the result or errno in the usual
 282  * way; the main loop code will take care of restarting the syscall
 283  * if appropriate.
 284  *
 285  * (If the implementation needs to make multiple host syscalls this is
 286  * OK; any which might really block must be via safe_syscall(); for those
 287  * which are only technically blocking (ie which we know in practice won't
 288  * stay in the host kernel indefinitely) it's OK to use libc if necessary.
 289  * You must be able to cope with backing out correctly if some safe_syscall
 290  * you make in the implementation returns either -TARGET_ERESTARTSYS or
 291  * EINTR though.)
 292  *
 293  * block_signals() cannot be used for interruptible syscalls.
 294  *
 295  *
 296  * How and why the safe_syscall implementation works:
 297  *
 298  * The basic setup is that we make the host syscall via a known
 299  * section of host native assembly. If a signal occurs, our signal
 300  * handler checks the interrupted host PC against the addresse of that
 301  * known section. If the PC is before or at the address of the syscall
 302  * instruction then we change the PC to point at a "return
 303  * -TARGET_ERESTARTSYS" code path instead, and then exit the signal handler
 304  * (causing the safe_syscall() call to immediately return that value).
 305  * Then in the main.c loop if we see this magic return value we adjust
 306  * the guest PC to wind it back to before the system call, and invoke
 307  * the guest signal handler as usual.
 308  *
 309  * This winding-back will happen in two cases:
 310  * (1) signal came in just before we took the host syscall (a race);
 311  *   in this case we'll take the guest signal and have another go
 312  *   at the syscall afterwards, and this is indistinguishable for the
 313  *   guest from the timing having been different such that the guest
 314  *   signal really did win the race
 315  * (2) signal came in while the host syscall was blocking, and the
 316  *   host kernel decided the syscall should be restarted;
 317  *   in this case we want to restart the guest syscall also, and so
 318  *   rewinding is the right thing. (Note that "restart" semantics mean
 319  *   "first call the signal handler, then reattempt the syscall".)
 320  * The other situation to consider is when a signal came in while the
 321  * host syscall was blocking, and the host kernel decided that the syscall
 322  * should not be restarted; in this case QEMU's host signal handler will
 323  * be invoked with the PC pointing just after the syscall instruction,
 324  * with registers indicating an EINTR return; the special code in the
 325  * handler will not kick in, and we will return EINTR to the guest as
 326  * we should.
 327  *
 328  * Notice that we can leave the host kernel to make the decision for
 329  * us about whether to do a restart of the syscall or not; we do not
 330  * need to check SA_RESTART flags in QEMU or distinguish the various
 331  * kinds of restartability.
 332  */
 333 #ifdef HAVE_SAFE_SYSCALL
 334 /* The core part of this function is implemented in assembly */
 335 extern long safe_syscall_base(int *pending, long number, ...);
 336
 337 #define safe_syscall(...)                                               \
 338     ({                                                                  \
 339         long ret_;                                                      \
 340         int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \
 341         ret_ = safe_syscall_base(psp_, __VA_ARGS__);                    \
 342         if (is_error(ret_)) {                                           \
 343             errno = -ret_;                                              \
 344             ret_ = -1;                                                  \
 345         }                                                               \
 346         ret_;                                                           \
 347     })
 348
 349 #else
 350
 351 /* Fallback for architectures which don't yet provide a safe-syscall assembly
 352  * fragment; note that this is racy!
 353  * This should go away when all host architectures have been updated.
 354  */
 355 #define safe_syscall syscall
 356
 357 #endif
 358
 359 /* syscall.c */
 360 int host_to_target_waitstatus(int status);
 361
 362 /* strace.c */
 363 void print_syscall(int num,
 364                    abi_long arg1, abi_long arg2, abi_long arg3,
 365                    abi_long arg4, abi_long arg5, abi_long arg6);
 366 void print_syscall_ret(int num, abi_long arg1);
 367 /**
 368  * print_taken_signal:
 369  * @target_signum: target signal being taken
 370  * @tinfo: target_siginfo_t which will be passed to the guest for the signal
 371  *
 372  * Print strace output indicating that this signal is being taken by the guest,
 373  * in a format similar to:
 374  * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
 375  */
 376 void print_taken_signal(int target_signum, const target_siginfo_t *tinfo);
 377 extern int do_strace;
 378
 379 /* signal.c */
 380 void process_pending_signals(CPUArchState *cpu_env);
 381 void signal_init(void);
 382 int queue_signal(CPUArchState *env, int sig, int si_type,
 383                  target_siginfo_t *info);
 384 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info);
 385 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo);
 386 int target_to_host_signal(int sig);
 387 int host_to_target_signal(int sig);
 388 long do_sigreturn(CPUArchState *env);
 389 long do_rt_sigreturn(CPUArchState *env);
 390 abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp);
 391 int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset);
 392 /**
 393  * block_signals: block all signals while handling this guest syscall
 394  *
 395  * Block all signals, and arrange that the signal mask is returned to
 396  * its correct value for the guest before we resume execution of guest code.
 397  * If this function returns non-zero, then the caller should immediately
 398  * return -TARGET_ERESTARTSYS to the main loop, which will take the pending
 399  * signal and restart execution of the syscall.
 400  * If block_signals() returns zero, then the caller can continue with
 401  * emulation of the system call knowing that no signals can be taken
 402  * (and therefore that no race conditions will result).
 403  * This should only be called once, because if it is called a second time
 404  * it will always return non-zero. (Think of it like a mutex that can't
 405  * be recursively locked.)
 406  * Signals will be unblocked again by process_pending_signals().
 407  *
 408  * Return value: non-zero if there was a pending signal, zero if not.
 409  */
 410 int block_signals(void); /* Returns non zero if signal pending */
 411
 412 #ifdef TARGET_I386
 413 /* vm86.c */
 414 void save_v86_state(CPUX86State *env);
 415 void handle_vm86_trap(CPUX86State *env, int trapno);
 416 void handle_vm86_fault(CPUX86State *env);
 417 int do_vm86(CPUX86State *env, long subfunction, abi_ulong v86_addr);
 418 #elif defined(TARGET_SPARC64)
 419 void sparc64_set_context(CPUSPARCState *env);
 420 void sparc64_get_context(CPUSPARCState *env);
 421 #endif
 422
 423 /* mmap.c */
 424 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
 425 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
 426                      int flags, int fd, abi_ulong offset);
 427 int target_munmap(abi_ulong start, abi_ulong len);
 428 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
 429                        abi_ulong new_size, unsigned long flags,
 430                        abi_ulong new_addr);
 431 int target_msync(abi_ulong start, abi_ulong len, int flags);
 432 extern unsigned long last_brk;
 433 extern abi_ulong mmap_next_start;
 434 abi_ulong mmap_find_vma(abi_ulong, abi_ulong);
 435 void mmap_fork_start(void);
 436 void mmap_fork_end(int child);
 437
 438 /* main.c */
 439 extern unsigned long guest_stack_size;
 440
 441 /* user access */
 442
 443 #define VERIFY_READ 0
 444 #define VERIFY_WRITE 1 /* implies read access */
 445
 446 static inline int access_ok(int type, abi_ulong addr, abi_ulong size)
 447 {
 448     return page_check_range((target_ulong)addr, size,
 449                             (type == VERIFY_READ) ? PAGE_READ : (PAGE_READ | PAGE_WRITE)) == 0;
 450 }
 451
 452 /* NOTE __get_user and __put_user use host pointers and don't check access.
 453    These are usually used to access struct data members once the struct has
 454    been locked - usually with lock_user_struct.  */
 455
 456 /* Tricky points:
 457    - Use __builtin_choose_expr to avoid type promotion from ?:,
 458    - Invalid sizes result in a compile time error stemming from
 459      the fact that abort has no parameters.
 460    - It's easier to use the endian-specific unaligned load/store
 461      functions than host-endian unaligned load/store plus tswapN.  */
 462
 463 #define __put_user_e(x, hptr, e)                                        \
 464   (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                   \
 465    __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,             \
 466    __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,             \
 467    __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))   \
 468      ((hptr), (x)), (void)0)
 469
 470 #define __get_user_e(x, hptr, e)                                        \
 471   ((x) = (typeof(*hptr))(                                               \
 472    __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                  \
 473    __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,            \
 474    __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,             \
 475    __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))   \
 476      (hptr)), (void)0)
 477
 478 #ifdef TARGET_WORDS_BIGENDIAN
 479 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
 480 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
 481 #else
 482 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
 483 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
 484 #endif
 485
 486 /* put_user()/get_user() take a guest address and check access */
 487 /* These are usually used to access an atomic data type, such as an int,
 488  * that has been passed by address.  These internally perform locking
 489  * and unlocking on the data type.
 490  */
 491 #define put_user(x, gaddr, target_type)                                 \
 492 ({                                                                      \
 493     abi_ulong __gaddr = (gaddr);                                        \
 494     target_type *__hptr;                                                \
 495     abi_long __ret = 0;                                                 \
 496     if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
 497         __put_user((x), __hptr);                                \
 498         unlock_user(__hptr, __gaddr, sizeof(target_type));              \
 499     } else                                                              \
 500         __ret = -TARGET_EFAULT;                                         \
 501     __ret;                                                              \
 502 })
 503
 504 #define get_user(x, gaddr, target_type)                                 \
 505 ({                                                                      \
 506     abi_ulong __gaddr = (gaddr);                                        \
 507     target_type *__hptr;                                                \
 508     abi_long __ret = 0;                                                 \
 509     if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
 510         __get_user((x), __hptr);                                \
 511         unlock_user(__hptr, __gaddr, 0);                                \
 512     } else {                                                            \
 513         /* avoid warning */                                             \
 514         (x) = 0;                                                        \
 515         __ret = -TARGET_EFAULT;                                         \
 516     }                                                                   \
 517     __ret;                                                              \
 518 })
 519
 520 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
 521 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
 522 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
 523 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
 524 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
 525 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
 526 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
 527 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
 528 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
 529 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
 530
 531 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
 532 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
 533 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
 534 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
 535 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
 536 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
 537 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
 538 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
 539 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
 540 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
 541
 542 /* copy_from_user() and copy_to_user() are usually used to copy data
 543  * buffers between the target and host.  These internally perform
 544  * locking/unlocking of the memory.
 545  */
 546 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
 547 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
 548
 549 /* Functions for accessing guest memory.  The tget and tput functions
 550    read/write single values, byteswapping as necessary.  The lock_user function
 551    gets a pointer to a contiguous area of guest memory, but does not perform
 552    any byteswapping.  lock_user may return either a pointer to the guest
 553    memory, or a temporary buffer.  */
 554
 555 /* Lock an area of guest memory into the host.  If copy is true then the
 556    host area will have the same contents as the guest.  */
 557 static inline void *lock_user(int type, abi_ulong guest_addr, long len, int copy)
 558 {
 559     if (!access_ok(type, guest_addr, len))
 560         return NULL;
 561 #ifdef DEBUG_REMAP
 562     {
 563         void *addr;
 564         addr = g_malloc(len);
 565         if (copy)
 566             memcpy(addr, g2h(guest_addr), len);
 567         else
 568             memset(addr, 0, len);
 569         return addr;
 570     }
 571 #else
 572     return g2h(guest_addr);
 573 #endif
 574 }
 575
 576 /* Unlock an area of guest memory.  The first LEN bytes must be
 577    flushed back to guest memory. host_ptr = NULL is explicitly
 578    allowed and does nothing. */
 579 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
 580                                long len)
 581 {
 582
 583 #ifdef DEBUG_REMAP
 584     if (!host_ptr)
 585         return;
 586     if (host_ptr == g2h(guest_addr))
 587         return;
 588     if (len > 0)
 589         memcpy(g2h(guest_addr), host_ptr, len);
 590     g_free(host_ptr);
 591 #endif
 592 }
 593
 594 /* Return the length of a string in target memory or -TARGET_EFAULT if
 595    access error. */
 596 abi_long target_strlen(abi_ulong gaddr);
 597
 598 /* Like lock_user but for null terminated strings.  */
 599 static inline void *lock_user_string(abi_ulong guest_addr)
 600 {
 601     abi_long len;
 602     len = target_strlen(guest_addr);
 603     if (len < 0)
 604         return NULL;
 605     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
 606 }
 607
 608 /* Helper macros for locking/unlocking a target struct.  */
 609 #define lock_user_struct(type, host_ptr, guest_addr, copy)      \
 610     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
 611 #define unlock_user_struct(host_ptr, guest_addr, copy)          \
 612     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
 613
 614 #include <pthread.h>
 615
 616 /* Include target-specific struct and function definitions;
 617  * they may need access to the target-independent structures
 618  * above, so include them last.
 619  */
 620 #include "target_cpu.h"
 621 #include "target_signal.h"
 622 #include "target_structs.h"
 623
 624 #endif /* QEMU_H */