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
  55         /* The fields below are used in FDPIC mode.  */
  56         abi_ulong       loadmap_addr;
  57         uint16_t        nsegs;
  58         void           *loadsegs;
  59         abi_ulong       pt_dynamic_addr;
  60         abi_ulong       interpreter_loadmap_addr;
  61         abi_ulong       interpreter_pt_dynamic_addr;
  62         struct image_info *other_info;
  63 };
  64
  65 #ifdef TARGET_I386
  66 /* Information about the current linux thread */
  67 struct vm86_saved_state {
  68     uint32_t eax; /* return code */
  69     uint32_t ebx;
  70     uint32_t ecx;
  71     uint32_t edx;
  72     uint32_t esi;
  73     uint32_t edi;
  74     uint32_t ebp;
  75     uint32_t esp;
  76     uint32_t eflags;
  77     uint32_t eip;
  78     uint16_t cs, ss, ds, es, fs, gs;
  79 };
  80 #endif
  81
  82 #if defined(TARGET_ARM) && defined(TARGET_ABI32)
  83 /* FPU emulator */
  84 #include "nwfpe/fpa11.h"
  85 #endif
  86
  87 #define MAX_SIGQUEUE_SIZE 1024
  88
  89 struct emulated_sigtable {
  90     int pending; /* true if signal is pending */
  91     target_siginfo_t info;
  92 };
  93
  94 /* NOTE: we force a big alignment so that the stack stored after is
  95    aligned too */
  96 typedef struct TaskState {
  97     pid_t ts_tid;     /* tid (or pid) of this task */
  98 #ifdef TARGET_ARM
  99 # ifdef TARGET_ABI32
 100     /* FPA state */
 101     FPA11 fpa;
 102 # endif
 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)
 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 /* Returns true if the image uses the FDPIC ABI. If this is the case,
 189  * we have to provide some information (loadmap, pt_dynamic_info) such
 190  * that the program can be relocated adequately. This is also useful
 191  * when handling signals.
 192  */
 193 int info_is_fdpic(struct image_info *info);
 194
 195 uint32_t get_elf_eflags(int fd);
 196 int load_elf_binary(struct linux_binprm *bprm, struct image_info *info);
 197 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info);
 198
 199 abi_long memcpy_to_target(abi_ulong dest, const void *src,
 200                           unsigned long len);
 201 void target_set_brk(abi_ulong new_brk);
 202 abi_long do_brk(abi_ulong new_brk);
 203 void syscall_init(void);
 204 abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
 205                     abi_long arg2, abi_long arg3, abi_long arg4,
 206                     abi_long arg5, abi_long arg6, abi_long arg7,
 207                     abi_long arg8);
 208 void gemu_log(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
 209 extern __thread CPUState *thread_cpu;
 210 void cpu_loop(CPUArchState *env);
 211 const char *target_strerror(int err);
 212 int get_osversion(void);
 213 void init_qemu_uname_release(void);
 214 void fork_start(void);
 215 void fork_end(int child);
 216
 217 /* Creates the initial guest address space in the host memory space using
 218  * the given host start address hint and size.  The guest_start parameter
 219  * specifies the start address of the guest space.  guest_base will be the
 220  * difference between the host start address computed by this function and
 221  * guest_start.  If fixed is specified, then the mapped address space must
 222  * start at host_start.  The real start address of the mapped memory space is
 223  * returned or -1 if there was an error.
 224  */
 225 unsigned long init_guest_space(unsigned long host_start,
 226                                unsigned long host_size,
 227                                unsigned long guest_start,
 228                                bool fixed);
 229
 230 #include "qemu/log.h"
 231
 232 /* safe_syscall.S */
 233
 234 /**
 235  * safe_syscall:
 236  * @int number: number of system call to make
 237  * ...: arguments to the system call
 238  *
 239  * Call a system call if guest signal not pending.
 240  * This has the same API as the libc syscall() function, except that it
 241  * may return -1 with errno == TARGET_ERESTARTSYS if a signal was pending.
 242  *
 243  * Returns: the system call result, or -1 with an error code in errno
 244  * (Errnos are host errnos; we rely on TARGET_ERESTARTSYS not clashing
 245  * with any of the host errno values.)
 246  */
 247
 248 /* A guide to using safe_syscall() to handle interactions between guest
 249  * syscalls and guest signals:
 250  *
 251  * Guest syscalls come in two flavours:
 252  *
 253  * (1) Non-interruptible syscalls
 254  *
 255  * These are guest syscalls that never get interrupted by signals and
 256  * so never return EINTR. They can be implemented straightforwardly in
 257  * QEMU: just make sure that if the implementation code has to make any
 258  * blocking calls that those calls are retried if they return EINTR.
 259  * It's also OK to implement these with safe_syscall, though it will be
 260  * a little less efficient if a signal is delivered at the 'wrong' moment.
 261  *
 262  * Some non-interruptible syscalls need to be handled using block_signals()
 263  * to block signals for the duration of the syscall. This mainly applies
 264  * to code which needs to modify the data structures used by the
 265  * host_signal_handler() function and the functions it calls, including
 266  * all syscalls which change the thread's signal mask.
 267  *
 268  * (2) Interruptible syscalls
 269  *
 270  * These are guest syscalls that can be interrupted by signals and
 271  * for which we need to either return EINTR or arrange for the guest
 272  * syscall to be restarted. This category includes both syscalls which
 273  * always restart (and in the kernel return -ERESTARTNOINTR), ones
 274  * which only restart if there is no handler (kernel returns -ERESTARTNOHAND
 275  * or -ERESTART_RESTARTBLOCK), and the most common kind which restart
 276  * if the handler was registered with SA_RESTART (kernel returns
 277  * -ERESTARTSYS). System calls which are only interruptible in some
 278  * situations (like 'open') also need to be handled this way.
 279  *
 280  * Here it is important that the host syscall is made
 281  * via this safe_syscall() function, and *not* via the host libc.
 282  * If the host libc is used then the implementation will appear to work
 283  * most of the time, but there will be a race condition where a
 284  * signal could arrive just before we make the host syscall inside libc,
 285  * and then then guest syscall will not correctly be interrupted.
 286  * Instead the implementation of the guest syscall can use the safe_syscall
 287  * function but otherwise just return the result or errno in the usual
 288  * way; the main loop code will take care of restarting the syscall
 289  * if appropriate.
 290  *
 291  * (If the implementation needs to make multiple host syscalls this is
 292  * OK; any which might really block must be via safe_syscall(); for those
 293  * which are only technically blocking (ie which we know in practice won't
 294  * stay in the host kernel indefinitely) it's OK to use libc if necessary.
 295  * You must be able to cope with backing out correctly if some safe_syscall
 296  * you make in the implementation returns either -TARGET_ERESTARTSYS or
 297  * EINTR though.)
 298  *
 299  * block_signals() cannot be used for interruptible syscalls.
 300  *
 301  *
 302  * How and why the safe_syscall implementation works:
 303  *
 304  * The basic setup is that we make the host syscall via a known
 305  * section of host native assembly. If a signal occurs, our signal
 306  * handler checks the interrupted host PC against the addresse of that
 307  * known section. If the PC is before or at the address of the syscall
 308  * instruction then we change the PC to point at a "return
 309  * -TARGET_ERESTARTSYS" code path instead, and then exit the signal handler
 310  * (causing the safe_syscall() call to immediately return that value).
 311  * Then in the main.c loop if we see this magic return value we adjust
 312  * the guest PC to wind it back to before the system call, and invoke
 313  * the guest signal handler as usual.
 314  *
 315  * This winding-back will happen in two cases:
 316  * (1) signal came in just before we took the host syscall (a race);
 317  *   in this case we'll take the guest signal and have another go
 318  *   at the syscall afterwards, and this is indistinguishable for the
 319  *   guest from the timing having been different such that the guest
 320  *   signal really did win the race
 321  * (2) signal came in while the host syscall was blocking, and the
 322  *   host kernel decided the syscall should be restarted;
 323  *   in this case we want to restart the guest syscall also, and so
 324  *   rewinding is the right thing. (Note that "restart" semantics mean
 325  *   "first call the signal handler, then reattempt the syscall".)
 326  * The other situation to consider is when a signal came in while the
 327  * host syscall was blocking, and the host kernel decided that the syscall
 328  * should not be restarted; in this case QEMU's host signal handler will
 329  * be invoked with the PC pointing just after the syscall instruction,
 330  * with registers indicating an EINTR return; the special code in the
 331  * handler will not kick in, and we will return EINTR to the guest as
 332  * we should.
 333  *
 334  * Notice that we can leave the host kernel to make the decision for
 335  * us about whether to do a restart of the syscall or not; we do not
 336  * need to check SA_RESTART flags in QEMU or distinguish the various
 337  * kinds of restartability.
 338  */
 339 #ifdef HAVE_SAFE_SYSCALL
 340 /* The core part of this function is implemented in assembly */
 341 extern long safe_syscall_base(int *pending, long number, ...);
 342
 343 #define safe_syscall(...)                                               \
 344     ({                                                                  \
 345         long ret_;                                                      \
 346         int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \
 347         ret_ = safe_syscall_base(psp_, __VA_ARGS__);                    \
 348         if (is_error(ret_)) {                                           \
 349             errno = -ret_;                                              \
 350             ret_ = -1;                                                  \
 351         }                                                               \
 352         ret_;                                                           \
 353     })
 354
 355 #else
 356
 357 /* Fallback for architectures which don't yet provide a safe-syscall assembly
 358  * fragment; note that this is racy!
 359  * This should go away when all host architectures have been updated.
 360  */
 361 #define safe_syscall syscall
 362
 363 #endif
 364
 365 /* syscall.c */
 366 int host_to_target_waitstatus(int status);
 367
 368 /* strace.c */
 369 void print_syscall(int num,
 370                    abi_long arg1, abi_long arg2, abi_long arg3,
 371                    abi_long arg4, abi_long arg5, abi_long arg6);
 372 void print_syscall_ret(int num, abi_long arg1);
 373 /**
 374  * print_taken_signal:
 375  * @target_signum: target signal being taken
 376  * @tinfo: target_siginfo_t which will be passed to the guest for the signal
 377  *
 378  * Print strace output indicating that this signal is being taken by the guest,
 379  * in a format similar to:
 380  * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
 381  */
 382 void print_taken_signal(int target_signum, const target_siginfo_t *tinfo);
 383 extern int do_strace;
 384
 385 /* signal.c */
 386 void process_pending_signals(CPUArchState *cpu_env);
 387 void signal_init(void);
 388 int queue_signal(CPUArchState *env, int sig, int si_type,
 389                  target_siginfo_t *info);
 390 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info);
 391 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo);
 392 int target_to_host_signal(int sig);
 393 int host_to_target_signal(int sig);
 394 long do_sigreturn(CPUArchState *env);
 395 long do_rt_sigreturn(CPUArchState *env);
 396 abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp);
 397 int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset);
 398 /**
 399  * block_signals: block all signals while handling this guest syscall
 400  *
 401  * Block all signals, and arrange that the signal mask is returned to
 402  * its correct value for the guest before we resume execution of guest code.
 403  * If this function returns non-zero, then the caller should immediately
 404  * return -TARGET_ERESTARTSYS to the main loop, which will take the pending
 405  * signal and restart execution of the syscall.
 406  * If block_signals() returns zero, then the caller can continue with
 407  * emulation of the system call knowing that no signals can be taken
 408  * (and therefore that no race conditions will result).
 409  * This should only be called once, because if it is called a second time
 410  * it will always return non-zero. (Think of it like a mutex that can't
 411  * be recursively locked.)
 412  * Signals will be unblocked again by process_pending_signals().
 413  *
 414  * Return value: non-zero if there was a pending signal, zero if not.
 415  */
 416 int block_signals(void); /* Returns non zero if signal pending */
 417
 418 #ifdef TARGET_I386
 419 /* vm86.c */
 420 void save_v86_state(CPUX86State *env);
 421 void handle_vm86_trap(CPUX86State *env, int trapno);
 422 void handle_vm86_fault(CPUX86State *env);
 423 int do_vm86(CPUX86State *env, long subfunction, abi_ulong v86_addr);
 424 #elif defined(TARGET_SPARC64)
 425 void sparc64_set_context(CPUSPARCState *env);
 426 void sparc64_get_context(CPUSPARCState *env);
 427 #endif
 428
 429 /* mmap.c */
 430 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
 431 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
 432                      int flags, int fd, abi_ulong offset);
 433 int target_munmap(abi_ulong start, abi_ulong len);
 434 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
 435                        abi_ulong new_size, unsigned long flags,
 436                        abi_ulong new_addr);
 437 extern unsigned long last_brk;
 438 extern abi_ulong mmap_next_start;
 439 abi_ulong mmap_find_vma(abi_ulong, abi_ulong);
 440 void mmap_fork_start(void);
 441 void mmap_fork_end(int child);
 442
 443 /* main.c */
 444 extern unsigned long guest_stack_size;
 445
 446 /* user access */
 447
 448 #define VERIFY_READ 0
 449 #define VERIFY_WRITE 1 /* implies read access */
 450
 451 static inline int access_ok(int type, abi_ulong addr, abi_ulong size)
 452 {
 453     return page_check_range((target_ulong)addr, size,
 454                             (type == VERIFY_READ) ? PAGE_READ : (PAGE_READ | PAGE_WRITE)) == 0;
 455 }
 456
 457 /* NOTE __get_user and __put_user use host pointers and don't check access.
 458    These are usually used to access struct data members once the struct has
 459    been locked - usually with lock_user_struct.  */
 460
 461 /* Tricky points:
 462    - Use __builtin_choose_expr to avoid type promotion from ?:,
 463    - Invalid sizes result in a compile time error stemming from
 464      the fact that abort has no parameters.
 465    - It's easier to use the endian-specific unaligned load/store
 466      functions than host-endian unaligned load/store plus tswapN.  */
 467
 468 #define __put_user_e(x, hptr, e)                                        \
 469   (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                   \
 470    __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,             \
 471    __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,             \
 472    __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))   \
 473      ((hptr), (x)), (void)0)
 474
 475 #define __get_user_e(x, hptr, e)                                        \
 476   ((x) = (typeof(*hptr))(                                               \
 477    __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                  \
 478    __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,            \
 479    __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,             \
 480    __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))   \
 481      (hptr)), (void)0)
 482
 483 #ifdef TARGET_WORDS_BIGENDIAN
 484 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
 485 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
 486 #else
 487 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
 488 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
 489 #endif
 490
 491 /* put_user()/get_user() take a guest address and check access */
 492 /* These are usually used to access an atomic data type, such as an int,
 493  * that has been passed by address.  These internally perform locking
 494  * and unlocking on the data type.
 495  */
 496 #define put_user(x, gaddr, target_type)                                 \
 497 ({                                                                      \
 498     abi_ulong __gaddr = (gaddr);                                        \
 499     target_type *__hptr;                                                \
 500     abi_long __ret = 0;                                                 \
 501     if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
 502         __put_user((x), __hptr);                                \
 503         unlock_user(__hptr, __gaddr, sizeof(target_type));              \
 504     } else                                                              \
 505         __ret = -TARGET_EFAULT;                                         \
 506     __ret;                                                              \
 507 })
 508
 509 #define get_user(x, gaddr, target_type)                                 \
 510 ({                                                                      \
 511     abi_ulong __gaddr = (gaddr);                                        \
 512     target_type *__hptr;                                                \
 513     abi_long __ret = 0;                                                 \
 514     if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
 515         __get_user((x), __hptr);                                \
 516         unlock_user(__hptr, __gaddr, 0);                                \
 517     } else {                                                            \
 518         /* avoid warning */                                             \
 519         (x) = 0;                                                        \
 520         __ret = -TARGET_EFAULT;                                         \
 521     }                                                                   \
 522     __ret;                                                              \
 523 })
 524
 525 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
 526 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
 527 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
 528 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
 529 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
 530 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
 531 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
 532 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
 533 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
 534 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
 535
 536 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
 537 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
 538 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
 539 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
 540 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
 541 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
 542 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
 543 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
 544 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
 545 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
 546
 547 /* copy_from_user() and copy_to_user() are usually used to copy data
 548  * buffers between the target and host.  These internally perform
 549  * locking/unlocking of the memory.
 550  */
 551 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
 552 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
 553
 554 /* Functions for accessing guest memory.  The tget and tput functions
 555    read/write single values, byteswapping as necessary.  The lock_user function
 556    gets a pointer to a contiguous area of guest memory, but does not perform
 557    any byteswapping.  lock_user may return either a pointer to the guest
 558    memory, or a temporary buffer.  */
 559
 560 /* Lock an area of guest memory into the host.  If copy is true then the
 561    host area will have the same contents as the guest.  */
 562 static inline void *lock_user(int type, abi_ulong guest_addr, long len, int copy)
 563 {
 564     if (!access_ok(type, guest_addr, len))
 565         return NULL;
 566 #ifdef DEBUG_REMAP
 567     {
 568         void *addr;
 569         addr = g_malloc(len);
 570         if (copy)
 571             memcpy(addr, g2h(guest_addr), len);
 572         else
 573             memset(addr, 0, len);
 574         return addr;
 575     }
 576 #else
 577     return g2h(guest_addr);
 578 #endif
 579 }
 580
 581 /* Unlock an area of guest memory.  The first LEN bytes must be
 582    flushed back to guest memory. host_ptr = NULL is explicitly
 583    allowed and does nothing. */
 584 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
 585                                long len)
 586 {
 587
 588 #ifdef DEBUG_REMAP
 589     if (!host_ptr)
 590         return;
 591     if (host_ptr == g2h(guest_addr))
 592         return;
 593     if (len > 0)
 594         memcpy(g2h(guest_addr), host_ptr, len);
 595     g_free(host_ptr);
 596 #endif
 597 }
 598
 599 /* Return the length of a string in target memory or -TARGET_EFAULT if
 600    access error. */
 601 abi_long target_strlen(abi_ulong gaddr);
 602
 603 /* Like lock_user but for null terminated strings.  */
 604 static inline void *lock_user_string(abi_ulong guest_addr)
 605 {
 606     abi_long len;
 607     len = target_strlen(guest_addr);
 608     if (len < 0)
 609         return NULL;
 610     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
 611 }
 612
 613 /* Helper macros for locking/unlocking a target struct.  */
 614 #define lock_user_struct(type, host_ptr, guest_addr, copy)      \
 615     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
 616 #define unlock_user_struct(host_ptr, guest_addr, copy)          \
 617     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
 618
 619 #include <pthread.h>
 620
 621 /* Include target-specific struct and function definitions;
 622  * they may need access to the target-independent structures
 623  * above, so include them last.
 624  */
 625 #include "target_cpu.h"
 626 #include "target_structs.h"
 627
 628 #endif /* QEMU_H */