xref: /openbmc/qemu/linux-user/qemu.h (revision 4a09d0bb)
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 */
626