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