xref: /qemu/linux-user/qemu.h (revision 892bd32e)
1 #ifndef QEMU_H
2 #define QEMU_H
3 
4 #include "hostdep.h"
5 #include "cpu.h"
6 #include "exec/exec-all.h"
7 #include "exec/cpu_ldst.h"
8 
9 #undef DEBUG_REMAP
10 #ifdef DEBUG_REMAP
11 #endif /* DEBUG_REMAP */
12 
13 #include "exec/user/abitypes.h"
14 
15 #include "exec/user/thunk.h"
16 #include "syscall_defs.h"
17 #include "target_syscall.h"
18 #include "exec/gdbstub.h"
19 #include "qemu/queue.h"
20 
21 #define THREAD __thread
22 
23 /* This struct is used to hold certain information about the image.
24  * Basically, it replicates in user space what would be certain
25  * task_struct fields in the kernel
26  */
27 struct image_info {
28         abi_ulong       load_bias;
29         abi_ulong       load_addr;
30         abi_ulong       start_code;
31         abi_ulong       end_code;
32         abi_ulong       start_data;
33         abi_ulong       end_data;
34         abi_ulong       start_brk;
35         abi_ulong       brk;
36         abi_ulong       start_mmap;
37         abi_ulong       start_stack;
38         abi_ulong       stack_limit;
39         abi_ulong       entry;
40         abi_ulong       code_offset;
41         abi_ulong       data_offset;
42         abi_ulong       saved_auxv;
43         abi_ulong       auxv_len;
44         abi_ulong       arg_start;
45         abi_ulong       arg_end;
46         uint32_t        elf_flags;
47 	int		personality;
48 #ifdef CONFIG_USE_FDPIC
49         abi_ulong       loadmap_addr;
50         uint16_t        nsegs;
51         void           *loadsegs;
52         abi_ulong       pt_dynamic_addr;
53         struct image_info *other_info;
54 #endif
55 };
56 
57 #ifdef TARGET_I386
58 /* Information about the current linux thread */
59 struct vm86_saved_state {
60     uint32_t eax; /* return code */
61     uint32_t ebx;
62     uint32_t ecx;
63     uint32_t edx;
64     uint32_t esi;
65     uint32_t edi;
66     uint32_t ebp;
67     uint32_t esp;
68     uint32_t eflags;
69     uint32_t eip;
70     uint16_t cs, ss, ds, es, fs, gs;
71 };
72 #endif
73 
74 #if defined(TARGET_ARM) && defined(TARGET_ABI32)
75 /* FPU emulator */
76 #include "nwfpe/fpa11.h"
77 #endif
78 
79 #define MAX_SIGQUEUE_SIZE 1024
80 
81 struct emulated_sigtable {
82     int pending; /* true if signal is pending */
83     target_siginfo_t info;
84 };
85 
86 /* NOTE: we force a big alignment so that the stack stored after is
87    aligned too */
88 typedef struct TaskState {
89     pid_t ts_tid;     /* tid (or pid) of this task */
90 #ifdef TARGET_ARM
91 # ifdef TARGET_ABI32
92     /* FPA state */
93     FPA11 fpa;
94 # endif
95     int swi_errno;
96 #endif
97 #ifdef TARGET_UNICORE32
98     int swi_errno;
99 #endif
100 #if defined(TARGET_I386) && !defined(TARGET_X86_64)
101     abi_ulong target_v86;
102     struct vm86_saved_state vm86_saved_regs;
103     struct target_vm86plus_struct vm86plus;
104     uint32_t v86flags;
105     uint32_t v86mask;
106 #endif
107     abi_ulong child_tidptr;
108 #ifdef TARGET_M68K
109     int sim_syscalls;
110     abi_ulong tp_value;
111 #endif
112 #if defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_UNICORE32)
113     /* Extra fields for semihosted binaries.  */
114     uint32_t heap_base;
115     uint32_t heap_limit;
116 #endif
117     uint32_t stack_base;
118     int used; /* non zero if used */
119     struct image_info *info;
120     struct linux_binprm *bprm;
121 
122     struct emulated_sigtable sync_signal;
123     struct emulated_sigtable sigtab[TARGET_NSIG];
124     /* This thread's signal mask, as requested by the guest program.
125      * The actual signal mask of this thread may differ:
126      *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
127      *  + sometimes we block all signals to avoid races
128      */
129     sigset_t signal_mask;
130     /* The signal mask imposed by a guest sigsuspend syscall, if we are
131      * currently in the middle of such a syscall
132      */
133     sigset_t sigsuspend_mask;
134     /* Nonzero if we're leaving a sigsuspend and sigsuspend_mask is valid. */
135     int in_sigsuspend;
136 
137     /* Nonzero if process_pending_signals() needs to do something (either
138      * handle a pending signal or unblock signals).
139      * This flag is written from a signal handler so should be accessed via
140      * the atomic_read() and atomic_write() functions. (It is not accessed
141      * from multiple threads.)
142      */
143     int signal_pending;
144 
145 } __attribute__((aligned(16))) TaskState;
146 
147 extern char *exec_path;
148 void init_task_state(TaskState *ts);
149 void task_settid(TaskState *);
150 void stop_all_tasks(void);
151 extern const char *qemu_uname_release;
152 extern unsigned long mmap_min_addr;
153 
154 /* ??? See if we can avoid exposing so much of the loader internals.  */
155 
156 /* Read a good amount of data initially, to hopefully get all the
157    program headers loaded.  */
158 #define BPRM_BUF_SIZE  1024
159 
160 /*
161  * This structure is used to hold the arguments that are
162  * used when loading binaries.
163  */
164 struct linux_binprm {
165         char buf[BPRM_BUF_SIZE] __attribute__((aligned));
166         abi_ulong p;
167 	int fd;
168         int e_uid, e_gid;
169         int argc, envc;
170         char **argv;
171         char **envp;
172         char * filename;        /* Name of binary */
173         int (*core_dump)(int, const CPUArchState *); /* coredump routine */
174 };
175 
176 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
177 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
178                               abi_ulong stringp, int push_ptr);
179 int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
180              struct target_pt_regs * regs, struct image_info *infop,
181              struct linux_binprm *);
182 
183 int load_elf_binary(struct linux_binprm *bprm, struct image_info *info);
184 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info);
185 
186 abi_long memcpy_to_target(abi_ulong dest, const void *src,
187                           unsigned long len);
188 void target_set_brk(abi_ulong new_brk);
189 abi_long do_brk(abi_ulong new_brk);
190 void syscall_init(void);
191 abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
192                     abi_long arg2, abi_long arg3, abi_long arg4,
193                     abi_long arg5, abi_long arg6, abi_long arg7,
194                     abi_long arg8);
195 void gemu_log(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
196 extern THREAD CPUState *thread_cpu;
197 void cpu_loop(CPUArchState *env);
198 const char *target_strerror(int err);
199 int get_osversion(void);
200 void init_qemu_uname_release(void);
201 void fork_start(void);
202 void fork_end(int child);
203 
204 /* Creates the initial guest address space in the host memory space using
205  * the given host start address hint and size.  The guest_start parameter
206  * specifies the start address of the guest space.  guest_base will be the
207  * difference between the host start address computed by this function and
208  * guest_start.  If fixed is specified, then the mapped address space must
209  * start at host_start.  The real start address of the mapped memory space is
210  * returned or -1 if there was an error.
211  */
212 unsigned long init_guest_space(unsigned long host_start,
213                                unsigned long host_size,
214                                unsigned long guest_start,
215                                bool fixed);
216 
217 #include "qemu/log.h"
218 
219 /* safe_syscall.S */
220 
221 /**
222  * safe_syscall:
223  * @int number: number of system call to make
224  * ...: arguments to the system call
225  *
226  * Call a system call if guest signal not pending.
227  * This has the same API as the libc syscall() function, except that it
228  * may return -1 with errno == TARGET_ERESTARTSYS if a signal was pending.
229  *
230  * Returns: the system call result, or -1 with an error code in errno
231  * (Errnos are host errnos; we rely on TARGET_ERESTARTSYS not clashing
232  * with any of the host errno values.)
233  */
234 
235 /* A guide to using safe_syscall() to handle interactions between guest
236  * syscalls and guest signals:
237  *
238  * Guest syscalls come in two flavours:
239  *
240  * (1) Non-interruptible syscalls
241  *
242  * These are guest syscalls that never get interrupted by signals and
243  * so never return EINTR. They can be implemented straightforwardly in
244  * QEMU: just make sure that if the implementation code has to make any
245  * blocking calls that those calls are retried if they return EINTR.
246  * It's also OK to implement these with safe_syscall, though it will be
247  * a little less efficient if a signal is delivered at the 'wrong' moment.
248  *
249  * Some non-interruptible syscalls need to be handled using block_signals()
250  * to block signals for the duration of the syscall. This mainly applies
251  * to code which needs to modify the data structures used by the
252  * host_signal_handler() function and the functions it calls, including
253  * all syscalls which change the thread's signal mask.
254  *
255  * (2) Interruptible syscalls
256  *
257  * These are guest syscalls that can be interrupted by signals and
258  * for which we need to either return EINTR or arrange for the guest
259  * syscall to be restarted. This category includes both syscalls which
260  * always restart (and in the kernel return -ERESTARTNOINTR), ones
261  * which only restart if there is no handler (kernel returns -ERESTARTNOHAND
262  * or -ERESTART_RESTARTBLOCK), and the most common kind which restart
263  * if the handler was registered with SA_RESTART (kernel returns
264  * -ERESTARTSYS). System calls which are only interruptible in some
265  * situations (like 'open') also need to be handled this way.
266  *
267  * Here it is important that the host syscall is made
268  * via this safe_syscall() function, and *not* via the host libc.
269  * If the host libc is used then the implementation will appear to work
270  * most of the time, but there will be a race condition where a
271  * signal could arrive just before we make the host syscall inside libc,
272  * and then then guest syscall will not correctly be interrupted.
273  * Instead the implementation of the guest syscall can use the safe_syscall
274  * function but otherwise just return the result or errno in the usual
275  * way; the main loop code will take care of restarting the syscall
276  * if appropriate.
277  *
278  * (If the implementation needs to make multiple host syscalls this is
279  * OK; any which might really block must be via safe_syscall(); for those
280  * which are only technically blocking (ie which we know in practice won't
281  * stay in the host kernel indefinitely) it's OK to use libc if necessary.
282  * You must be able to cope with backing out correctly if some safe_syscall
283  * you make in the implementation returns either -TARGET_ERESTARTSYS or
284  * EINTR though.)
285  *
286  * block_signals() cannot be used for interruptible syscalls.
287  *
288  *
289  * How and why the safe_syscall implementation works:
290  *
291  * The basic setup is that we make the host syscall via a known
292  * section of host native assembly. If a signal occurs, our signal
293  * handler checks the interrupted host PC against the addresse of that
294  * known section. If the PC is before or at the address of the syscall
295  * instruction then we change the PC to point at a "return
296  * -TARGET_ERESTARTSYS" code path instead, and then exit the signal handler
297  * (causing the safe_syscall() call to immediately return that value).
298  * Then in the main.c loop if we see this magic return value we adjust
299  * the guest PC to wind it back to before the system call, and invoke
300  * the guest signal handler as usual.
301  *
302  * This winding-back will happen in two cases:
303  * (1) signal came in just before we took the host syscall (a race);
304  *   in this case we'll take the guest signal and have another go
305  *   at the syscall afterwards, and this is indistinguishable for the
306  *   guest from the timing having been different such that the guest
307  *   signal really did win the race
308  * (2) signal came in while the host syscall was blocking, and the
309  *   host kernel decided the syscall should be restarted;
310  *   in this case we want to restart the guest syscall also, and so
311  *   rewinding is the right thing. (Note that "restart" semantics mean
312  *   "first call the signal handler, then reattempt the syscall".)
313  * The other situation to consider is when a signal came in while the
314  * host syscall was blocking, and the host kernel decided that the syscall
315  * should not be restarted; in this case QEMU's host signal handler will
316  * be invoked with the PC pointing just after the syscall instruction,
317  * with registers indicating an EINTR return; the special code in the
318  * handler will not kick in, and we will return EINTR to the guest as
319  * we should.
320  *
321  * Notice that we can leave the host kernel to make the decision for
322  * us about whether to do a restart of the syscall or not; we do not
323  * need to check SA_RESTART flags in QEMU or distinguish the various
324  * kinds of restartability.
325  */
326 #ifdef HAVE_SAFE_SYSCALL
327 /* The core part of this function is implemented in assembly */
328 extern long safe_syscall_base(int *pending, long number, ...);
329 
330 #define safe_syscall(...)                                               \
331     ({                                                                  \
332         long ret_;                                                      \
333         int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \
334         ret_ = safe_syscall_base(psp_, __VA_ARGS__);                    \
335         if (is_error(ret_)) {                                           \
336             errno = -ret_;                                              \
337             ret_ = -1;                                                  \
338         }                                                               \
339         ret_;                                                           \
340     })
341 
342 #else
343 
344 /* Fallback for architectures which don't yet provide a safe-syscall assembly
345  * fragment; note that this is racy!
346  * This should go away when all host architectures have been updated.
347  */
348 #define safe_syscall syscall
349 
350 #endif
351 
352 /* syscall.c */
353 int host_to_target_waitstatus(int status);
354 
355 /* strace.c */
356 void print_syscall(int num,
357                    abi_long arg1, abi_long arg2, abi_long arg3,
358                    abi_long arg4, abi_long arg5, abi_long arg6);
359 void print_syscall_ret(int num, abi_long arg1);
360 extern int do_strace;
361 
362 /* signal.c */
363 void process_pending_signals(CPUArchState *cpu_env);
364 void signal_init(void);
365 int queue_signal(CPUArchState *env, int sig, target_siginfo_t *info);
366 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info);
367 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo);
368 int target_to_host_signal(int sig);
369 int host_to_target_signal(int sig);
370 long do_sigreturn(CPUArchState *env);
371 long do_rt_sigreturn(CPUArchState *env);
372 abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp);
373 int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset);
374 /**
375  * block_signals: block all signals while handling this guest syscall
376  *
377  * Block all signals, and arrange that the signal mask is returned to
378  * its correct value for the guest before we resume execution of guest code.
379  * If this function returns non-zero, then the caller should immediately
380  * return -TARGET_ERESTARTSYS to the main loop, which will take the pending
381  * signal and restart execution of the syscall.
382  * If block_signals() returns zero, then the caller can continue with
383  * emulation of the system call knowing that no signals can be taken
384  * (and therefore that no race conditions will result).
385  * This should only be called once, because if it is called a second time
386  * it will always return non-zero. (Think of it like a mutex that can't
387  * be recursively locked.)
388  * Signals will be unblocked again by process_pending_signals().
389  *
390  * Return value: non-zero if there was a pending signal, zero if not.
391  */
392 int block_signals(void); /* Returns non zero if signal pending */
393 
394 #ifdef TARGET_I386
395 /* vm86.c */
396 void save_v86_state(CPUX86State *env);
397 void handle_vm86_trap(CPUX86State *env, int trapno);
398 void handle_vm86_fault(CPUX86State *env);
399 int do_vm86(CPUX86State *env, long subfunction, abi_ulong v86_addr);
400 #elif defined(TARGET_SPARC64)
401 void sparc64_set_context(CPUSPARCState *env);
402 void sparc64_get_context(CPUSPARCState *env);
403 #endif
404 
405 /* mmap.c */
406 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
407 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
408                      int flags, int fd, abi_ulong offset);
409 int target_munmap(abi_ulong start, abi_ulong len);
410 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
411                        abi_ulong new_size, unsigned long flags,
412                        abi_ulong new_addr);
413 int target_msync(abi_ulong start, abi_ulong len, int flags);
414 extern unsigned long last_brk;
415 extern abi_ulong mmap_next_start;
416 abi_ulong mmap_find_vma(abi_ulong, abi_ulong);
417 void cpu_list_lock(void);
418 void cpu_list_unlock(void);
419 void mmap_fork_start(void);
420 void mmap_fork_end(int child);
421 
422 /* main.c */
423 extern unsigned long guest_stack_size;
424 
425 /* user access */
426 
427 #define VERIFY_READ 0
428 #define VERIFY_WRITE 1 /* implies read access */
429 
430 static inline int access_ok(int type, abi_ulong addr, abi_ulong size)
431 {
432     return page_check_range((target_ulong)addr, size,
433                             (type == VERIFY_READ) ? PAGE_READ : (PAGE_READ | PAGE_WRITE)) == 0;
434 }
435 
436 /* NOTE __get_user and __put_user use host pointers and don't check access.
437    These are usually used to access struct data members once the struct has
438    been locked - usually with lock_user_struct.  */
439 
440 /* Tricky points:
441    - Use __builtin_choose_expr to avoid type promotion from ?:,
442    - Invalid sizes result in a compile time error stemming from
443      the fact that abort has no parameters.
444    - It's easier to use the endian-specific unaligned load/store
445      functions than host-endian unaligned load/store plus tswapN.  */
446 
447 #define __put_user_e(x, hptr, e)                                        \
448   (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                   \
449    __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,             \
450    __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,             \
451    __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))   \
452      ((hptr), (x)), (void)0)
453 
454 #define __get_user_e(x, hptr, e)                                        \
455   ((x) = (typeof(*hptr))(                                               \
456    __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                  \
457    __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,            \
458    __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,             \
459    __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))   \
460      (hptr)), (void)0)
461 
462 #ifdef TARGET_WORDS_BIGENDIAN
463 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
464 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
465 #else
466 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
467 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
468 #endif
469 
470 /* put_user()/get_user() take a guest address and check access */
471 /* These are usually used to access an atomic data type, such as an int,
472  * that has been passed by address.  These internally perform locking
473  * and unlocking on the data type.
474  */
475 #define put_user(x, gaddr, target_type)					\
476 ({									\
477     abi_ulong __gaddr = (gaddr);					\
478     target_type *__hptr;						\
479     abi_long __ret = 0;							\
480     if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
481         __put_user((x), __hptr);				\
482         unlock_user(__hptr, __gaddr, sizeof(target_type));		\
483     } else								\
484         __ret = -TARGET_EFAULT;						\
485     __ret;								\
486 })
487 
488 #define get_user(x, gaddr, target_type)					\
489 ({									\
490     abi_ulong __gaddr = (gaddr);					\
491     target_type *__hptr;						\
492     abi_long __ret = 0;							\
493     if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
494         __get_user((x), __hptr);				\
495         unlock_user(__hptr, __gaddr, 0);				\
496     } else {								\
497         /* avoid warning */						\
498         (x) = 0;							\
499         __ret = -TARGET_EFAULT;						\
500     }									\
501     __ret;								\
502 })
503 
504 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
505 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
506 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
507 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
508 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
509 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
510 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
511 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
512 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
513 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
514 
515 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
516 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
517 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
518 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
519 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
520 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
521 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
522 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
523 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
524 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
525 
526 /* copy_from_user() and copy_to_user() are usually used to copy data
527  * buffers between the target and host.  These internally perform
528  * locking/unlocking of the memory.
529  */
530 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
531 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
532 
533 /* Functions for accessing guest memory.  The tget and tput functions
534    read/write single values, byteswapping as necessary.  The lock_user function
535    gets a pointer to a contiguous area of guest memory, but does not perform
536    any byteswapping.  lock_user may return either a pointer to the guest
537    memory, or a temporary buffer.  */
538 
539 /* Lock an area of guest memory into the host.  If copy is true then the
540    host area will have the same contents as the guest.  */
541 static inline void *lock_user(int type, abi_ulong guest_addr, long len, int copy)
542 {
543     if (!access_ok(type, guest_addr, len))
544         return NULL;
545 #ifdef DEBUG_REMAP
546     {
547         void *addr;
548         addr = malloc(len);
549         if (copy)
550             memcpy(addr, g2h(guest_addr), len);
551         else
552             memset(addr, 0, len);
553         return addr;
554     }
555 #else
556     return g2h(guest_addr);
557 #endif
558 }
559 
560 /* Unlock an area of guest memory.  The first LEN bytes must be
561    flushed back to guest memory. host_ptr = NULL is explicitly
562    allowed and does nothing. */
563 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
564                                long len)
565 {
566 
567 #ifdef DEBUG_REMAP
568     if (!host_ptr)
569         return;
570     if (host_ptr == g2h(guest_addr))
571         return;
572     if (len > 0)
573         memcpy(g2h(guest_addr), host_ptr, len);
574     free(host_ptr);
575 #endif
576 }
577 
578 /* Return the length of a string in target memory or -TARGET_EFAULT if
579    access error. */
580 abi_long target_strlen(abi_ulong gaddr);
581 
582 /* Like lock_user but for null terminated strings.  */
583 static inline void *lock_user_string(abi_ulong guest_addr)
584 {
585     abi_long len;
586     len = target_strlen(guest_addr);
587     if (len < 0)
588         return NULL;
589     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
590 }
591 
592 /* Helper macros for locking/unlocking a target struct.  */
593 #define lock_user_struct(type, host_ptr, guest_addr, copy)	\
594     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
595 #define unlock_user_struct(host_ptr, guest_addr, copy)		\
596     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
597 
598 #include <pthread.h>
599 
600 /* Include target-specific struct and function definitions;
601  * they may need access to the target-independent structures
602  * above, so include them last.
603  */
604 #include "target_cpu.h"
605 #include "target_signal.h"
606 #include "target_structs.h"
607 
608 #endif /* QEMU_H */
609