xref: /openbmc/qemu/linux-user/qemu.h (revision dc5bd18f)
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 */
625