xref: /openbmc/qemu/linux-user/qemu.h (revision 77d361b1)
1 #ifndef QEMU_H
2 #define QEMU_H
3 
4 #include "hostdep.h"
5 #include "cpu.h"
6 #include "exec/exec-all.h"
7 #include "exec/cpu_ldst.h"
8 
9 #undef DEBUG_REMAP
10 #ifdef DEBUG_REMAP
11 #endif /* DEBUG_REMAP */
12 
13 #include "exec/user/abitypes.h"
14 
15 #include "exec/user/thunk.h"
16 #include "syscall_defs.h"
17 #include "target_syscall.h"
18 #include "exec/gdbstub.h"
19 #include "qemu/queue.h"
20 
21 /* This is the size of the host kernel's sigset_t, needed where we make
22  * direct system calls that take a sigset_t pointer and a size.
23  */
24 #define SIGSET_T_SIZE (_NSIG / 8)
25 
26 /* This struct is used to hold certain information about the image.
27  * Basically, it replicates in user space what would be certain
28  * task_struct fields in the kernel
29  */
30 struct image_info {
31         abi_ulong       load_bias;
32         abi_ulong       load_addr;
33         abi_ulong       start_code;
34         abi_ulong       end_code;
35         abi_ulong       start_data;
36         abi_ulong       end_data;
37         abi_ulong       start_brk;
38         abi_ulong       brk;
39         abi_ulong       start_mmap;
40         abi_ulong       start_stack;
41         abi_ulong       stack_limit;
42         abi_ulong       entry;
43         abi_ulong       code_offset;
44         abi_ulong       data_offset;
45         abi_ulong       saved_auxv;
46         abi_ulong       auxv_len;
47         abi_ulong       arg_start;
48         abi_ulong       arg_end;
49         abi_ulong       arg_strings;
50         abi_ulong       env_strings;
51         abi_ulong       file_string;
52         uint32_t        elf_flags;
53 	int		personality;
54 
55         /* The fields below are used in FDPIC mode.  */
56         abi_ulong       loadmap_addr;
57         uint16_t        nsegs;
58         void           *loadsegs;
59         abi_ulong       pt_dynamic_addr;
60         abi_ulong       interpreter_loadmap_addr;
61         abi_ulong       interpreter_pt_dynamic_addr;
62         struct image_info *other_info;
63 };
64 
65 #ifdef TARGET_I386
66 /* Information about the current linux thread */
67 struct vm86_saved_state {
68     uint32_t eax; /* return code */
69     uint32_t ebx;
70     uint32_t ecx;
71     uint32_t edx;
72     uint32_t esi;
73     uint32_t edi;
74     uint32_t ebp;
75     uint32_t esp;
76     uint32_t eflags;
77     uint32_t eip;
78     uint16_t cs, ss, ds, es, fs, gs;
79 };
80 #endif
81 
82 #if defined(TARGET_ARM) && defined(TARGET_ABI32)
83 /* FPU emulator */
84 #include "nwfpe/fpa11.h"
85 #endif
86 
87 #define MAX_SIGQUEUE_SIZE 1024
88 
89 struct emulated_sigtable {
90     int pending; /* true if signal is pending */
91     target_siginfo_t info;
92 };
93 
94 /* NOTE: we force a big alignment so that the stack stored after is
95    aligned too */
96 typedef struct TaskState {
97     pid_t ts_tid;     /* tid (or pid) of this task */
98 #ifdef TARGET_ARM
99 # ifdef TARGET_ABI32
100     /* FPA state */
101     FPA11 fpa;
102 # endif
103     int swi_errno;
104 #endif
105 #if defined(TARGET_I386) && !defined(TARGET_X86_64)
106     abi_ulong target_v86;
107     struct vm86_saved_state vm86_saved_regs;
108     struct target_vm86plus_struct vm86plus;
109     uint32_t v86flags;
110     uint32_t v86mask;
111 #endif
112     abi_ulong child_tidptr;
113 #ifdef TARGET_M68K
114     int sim_syscalls;
115     abi_ulong tp_value;
116 #endif
117 #if defined(TARGET_ARM) || defined(TARGET_M68K)
118     /* Extra fields for semihosted binaries.  */
119     abi_ulong heap_base;
120     abi_ulong heap_limit;
121 #endif
122     abi_ulong stack_base;
123     int used; /* non zero if used */
124     struct image_info *info;
125     struct linux_binprm *bprm;
126 
127     struct emulated_sigtable sync_signal;
128     struct emulated_sigtable sigtab[TARGET_NSIG];
129     /* This thread's signal mask, as requested by the guest program.
130      * The actual signal mask of this thread may differ:
131      *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
132      *  + sometimes we block all signals to avoid races
133      */
134     sigset_t signal_mask;
135     /* The signal mask imposed by a guest sigsuspend syscall, if we are
136      * currently in the middle of such a syscall
137      */
138     sigset_t sigsuspend_mask;
139     /* Nonzero if we're leaving a sigsuspend and sigsuspend_mask is valid. */
140     int in_sigsuspend;
141 
142     /* Nonzero if process_pending_signals() needs to do something (either
143      * handle a pending signal or unblock signals).
144      * This flag is written from a signal handler so should be accessed via
145      * the atomic_read() and atomic_write() functions. (It is not accessed
146      * from multiple threads.)
147      */
148     int signal_pending;
149 
150 } __attribute__((aligned(16))) TaskState;
151 
152 extern char *exec_path;
153 void init_task_state(TaskState *ts);
154 void task_settid(TaskState *);
155 void stop_all_tasks(void);
156 extern const char *qemu_uname_release;
157 extern unsigned long mmap_min_addr;
158 
159 /* ??? See if we can avoid exposing so much of the loader internals.  */
160 
161 /* Read a good amount of data initially, to hopefully get all the
162    program headers loaded.  */
163 #define BPRM_BUF_SIZE  1024
164 
165 /*
166  * This structure is used to hold the arguments that are
167  * used when loading binaries.
168  */
169 struct linux_binprm {
170         char buf[BPRM_BUF_SIZE] __attribute__((aligned));
171         abi_ulong p;
172 	int fd;
173         int e_uid, e_gid;
174         int argc, envc;
175         char **argv;
176         char **envp;
177         char * filename;        /* Name of binary */
178         int (*core_dump)(int, const CPUArchState *); /* coredump routine */
179 };
180 
181 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
182 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
183                               abi_ulong stringp, int push_ptr);
184 int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
185              struct target_pt_regs * regs, struct image_info *infop,
186              struct linux_binprm *);
187 
188 /* Returns true if the image uses the FDPIC ABI. If this is the case,
189  * we have to provide some information (loadmap, pt_dynamic_info) such
190  * that the program can be relocated adequately. This is also useful
191  * when handling signals.
192  */
193 int info_is_fdpic(struct image_info *info);
194 
195 uint32_t get_elf_eflags(int fd);
196 int load_elf_binary(struct linux_binprm *bprm, struct image_info *info);
197 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info);
198 
199 abi_long memcpy_to_target(abi_ulong dest, const void *src,
200                           unsigned long len);
201 void target_set_brk(abi_ulong new_brk);
202 abi_long do_brk(abi_ulong new_brk);
203 void syscall_init(void);
204 abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
205                     abi_long arg2, abi_long arg3, abi_long arg4,
206                     abi_long arg5, abi_long arg6, abi_long arg7,
207                     abi_long arg8);
208 void gemu_log(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
209 extern __thread CPUState *thread_cpu;
210 void cpu_loop(CPUArchState *env);
211 const char *target_strerror(int err);
212 int get_osversion(void);
213 void init_qemu_uname_release(void);
214 void fork_start(void);
215 void fork_end(int child);
216 
217 /* Creates the initial guest address space in the host memory space using
218  * the given host start address hint and size.  The guest_start parameter
219  * specifies the start address of the guest space.  guest_base will be the
220  * difference between the host start address computed by this function and
221  * guest_start.  If fixed is specified, then the mapped address space must
222  * start at host_start.  The real start address of the mapped memory space is
223  * returned or -1 if there was an error.
224  */
225 unsigned long init_guest_space(unsigned long host_start,
226                                unsigned long host_size,
227                                unsigned long guest_start,
228                                bool fixed);
229 
230 #include "qemu/log.h"
231 
232 /* safe_syscall.S */
233 
234 /**
235  * safe_syscall:
236  * @int number: number of system call to make
237  * ...: arguments to the system call
238  *
239  * Call a system call if guest signal not pending.
240  * This has the same API as the libc syscall() function, except that it
241  * may return -1 with errno == TARGET_ERESTARTSYS if a signal was pending.
242  *
243  * Returns: the system call result, or -1 with an error code in errno
244  * (Errnos are host errnos; we rely on TARGET_ERESTARTSYS not clashing
245  * with any of the host errno values.)
246  */
247 
248 /* A guide to using safe_syscall() to handle interactions between guest
249  * syscalls and guest signals:
250  *
251  * Guest syscalls come in two flavours:
252  *
253  * (1) Non-interruptible syscalls
254  *
255  * These are guest syscalls that never get interrupted by signals and
256  * so never return EINTR. They can be implemented straightforwardly in
257  * QEMU: just make sure that if the implementation code has to make any
258  * blocking calls that those calls are retried if they return EINTR.
259  * It's also OK to implement these with safe_syscall, though it will be
260  * a little less efficient if a signal is delivered at the 'wrong' moment.
261  *
262  * Some non-interruptible syscalls need to be handled using block_signals()
263  * to block signals for the duration of the syscall. This mainly applies
264  * to code which needs to modify the data structures used by the
265  * host_signal_handler() function and the functions it calls, including
266  * all syscalls which change the thread's signal mask.
267  *
268  * (2) Interruptible syscalls
269  *
270  * These are guest syscalls that can be interrupted by signals and
271  * for which we need to either return EINTR or arrange for the guest
272  * syscall to be restarted. This category includes both syscalls which
273  * always restart (and in the kernel return -ERESTARTNOINTR), ones
274  * which only restart if there is no handler (kernel returns -ERESTARTNOHAND
275  * or -ERESTART_RESTARTBLOCK), and the most common kind which restart
276  * if the handler was registered with SA_RESTART (kernel returns
277  * -ERESTARTSYS). System calls which are only interruptible in some
278  * situations (like 'open') also need to be handled this way.
279  *
280  * Here it is important that the host syscall is made
281  * via this safe_syscall() function, and *not* via the host libc.
282  * If the host libc is used then the implementation will appear to work
283  * most of the time, but there will be a race condition where a
284  * signal could arrive just before we make the host syscall inside libc,
285  * and then then guest syscall will not correctly be interrupted.
286  * Instead the implementation of the guest syscall can use the safe_syscall
287  * function but otherwise just return the result or errno in the usual
288  * way; the main loop code will take care of restarting the syscall
289  * if appropriate.
290  *
291  * (If the implementation needs to make multiple host syscalls this is
292  * OK; any which might really block must be via safe_syscall(); for those
293  * which are only technically blocking (ie which we know in practice won't
294  * stay in the host kernel indefinitely) it's OK to use libc if necessary.
295  * You must be able to cope with backing out correctly if some safe_syscall
296  * you make in the implementation returns either -TARGET_ERESTARTSYS or
297  * EINTR though.)
298  *
299  * block_signals() cannot be used for interruptible syscalls.
300  *
301  *
302  * How and why the safe_syscall implementation works:
303  *
304  * The basic setup is that we make the host syscall via a known
305  * section of host native assembly. If a signal occurs, our signal
306  * handler checks the interrupted host PC against the addresse of that
307  * known section. If the PC is before or at the address of the syscall
308  * instruction then we change the PC to point at a "return
309  * -TARGET_ERESTARTSYS" code path instead, and then exit the signal handler
310  * (causing the safe_syscall() call to immediately return that value).
311  * Then in the main.c loop if we see this magic return value we adjust
312  * the guest PC to wind it back to before the system call, and invoke
313  * the guest signal handler as usual.
314  *
315  * This winding-back will happen in two cases:
316  * (1) signal came in just before we took the host syscall (a race);
317  *   in this case we'll take the guest signal and have another go
318  *   at the syscall afterwards, and this is indistinguishable for the
319  *   guest from the timing having been different such that the guest
320  *   signal really did win the race
321  * (2) signal came in while the host syscall was blocking, and the
322  *   host kernel decided the syscall should be restarted;
323  *   in this case we want to restart the guest syscall also, and so
324  *   rewinding is the right thing. (Note that "restart" semantics mean
325  *   "first call the signal handler, then reattempt the syscall".)
326  * The other situation to consider is when a signal came in while the
327  * host syscall was blocking, and the host kernel decided that the syscall
328  * should not be restarted; in this case QEMU's host signal handler will
329  * be invoked with the PC pointing just after the syscall instruction,
330  * with registers indicating an EINTR return; the special code in the
331  * handler will not kick in, and we will return EINTR to the guest as
332  * we should.
333  *
334  * Notice that we can leave the host kernel to make the decision for
335  * us about whether to do a restart of the syscall or not; we do not
336  * need to check SA_RESTART flags in QEMU or distinguish the various
337  * kinds of restartability.
338  */
339 #ifdef HAVE_SAFE_SYSCALL
340 /* The core part of this function is implemented in assembly */
341 extern long safe_syscall_base(int *pending, long number, ...);
342 
343 #define safe_syscall(...)                                               \
344     ({                                                                  \
345         long ret_;                                                      \
346         int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \
347         ret_ = safe_syscall_base(psp_, __VA_ARGS__);                    \
348         if (is_error(ret_)) {                                           \
349             errno = -ret_;                                              \
350             ret_ = -1;                                                  \
351         }                                                               \
352         ret_;                                                           \
353     })
354 
355 #else
356 
357 /* Fallback for architectures which don't yet provide a safe-syscall assembly
358  * fragment; note that this is racy!
359  * This should go away when all host architectures have been updated.
360  */
361 #define safe_syscall syscall
362 
363 #endif
364 
365 /* syscall.c */
366 int host_to_target_waitstatus(int status);
367 
368 /* strace.c */
369 void print_syscall(int num,
370                    abi_long arg1, abi_long arg2, abi_long arg3,
371                    abi_long arg4, abi_long arg5, abi_long arg6);
372 void print_syscall_ret(int num, abi_long arg1);
373 /**
374  * print_taken_signal:
375  * @target_signum: target signal being taken
376  * @tinfo: target_siginfo_t which will be passed to the guest for the signal
377  *
378  * Print strace output indicating that this signal is being taken by the guest,
379  * in a format similar to:
380  * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
381  */
382 void print_taken_signal(int target_signum, const target_siginfo_t *tinfo);
383 extern int do_strace;
384 
385 /* signal.c */
386 void process_pending_signals(CPUArchState *cpu_env);
387 void signal_init(void);
388 int queue_signal(CPUArchState *env, int sig, int si_type,
389                  target_siginfo_t *info);
390 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info);
391 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo);
392 int target_to_host_signal(int sig);
393 int host_to_target_signal(int sig);
394 long do_sigreturn(CPUArchState *env);
395 long do_rt_sigreturn(CPUArchState *env);
396 abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp);
397 int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset);
398 /**
399  * block_signals: block all signals while handling this guest syscall
400  *
401  * Block all signals, and arrange that the signal mask is returned to
402  * its correct value for the guest before we resume execution of guest code.
403  * If this function returns non-zero, then the caller should immediately
404  * return -TARGET_ERESTARTSYS to the main loop, which will take the pending
405  * signal and restart execution of the syscall.
406  * If block_signals() returns zero, then the caller can continue with
407  * emulation of the system call knowing that no signals can be taken
408  * (and therefore that no race conditions will result).
409  * This should only be called once, because if it is called a second time
410  * it will always return non-zero. (Think of it like a mutex that can't
411  * be recursively locked.)
412  * Signals will be unblocked again by process_pending_signals().
413  *
414  * Return value: non-zero if there was a pending signal, zero if not.
415  */
416 int block_signals(void); /* Returns non zero if signal pending */
417 
418 #ifdef TARGET_I386
419 /* vm86.c */
420 void save_v86_state(CPUX86State *env);
421 void handle_vm86_trap(CPUX86State *env, int trapno);
422 void handle_vm86_fault(CPUX86State *env);
423 int do_vm86(CPUX86State *env, long subfunction, abi_ulong v86_addr);
424 #elif defined(TARGET_SPARC64)
425 void sparc64_set_context(CPUSPARCState *env);
426 void sparc64_get_context(CPUSPARCState *env);
427 #endif
428 
429 /* mmap.c */
430 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
431 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
432                      int flags, int fd, abi_ulong offset);
433 int target_munmap(abi_ulong start, abi_ulong len);
434 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
435                        abi_ulong new_size, unsigned long flags,
436                        abi_ulong new_addr);
437 extern unsigned long last_brk;
438 extern abi_ulong mmap_next_start;
439 abi_ulong mmap_find_vma(abi_ulong, abi_ulong);
440 void mmap_fork_start(void);
441 void mmap_fork_end(int child);
442 
443 /* main.c */
444 extern unsigned long guest_stack_size;
445 
446 /* user access */
447 
448 #define VERIFY_READ 0
449 #define VERIFY_WRITE 1 /* implies read access */
450 
451 static inline int access_ok(int type, abi_ulong addr, abi_ulong size)
452 {
453     return page_check_range((target_ulong)addr, size,
454                             (type == VERIFY_READ) ? PAGE_READ : (PAGE_READ | PAGE_WRITE)) == 0;
455 }
456 
457 /* NOTE __get_user and __put_user use host pointers and don't check access.
458    These are usually used to access struct data members once the struct has
459    been locked - usually with lock_user_struct.  */
460 
461 /* Tricky points:
462    - Use __builtin_choose_expr to avoid type promotion from ?:,
463    - Invalid sizes result in a compile time error stemming from
464      the fact that abort has no parameters.
465    - It's easier to use the endian-specific unaligned load/store
466      functions than host-endian unaligned load/store plus tswapN.  */
467 
468 #define __put_user_e(x, hptr, e)                                        \
469   (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                   \
470    __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,             \
471    __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,             \
472    __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))   \
473      ((hptr), (x)), (void)0)
474 
475 #define __get_user_e(x, hptr, e)                                        \
476   ((x) = (typeof(*hptr))(                                               \
477    __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                  \
478    __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,            \
479    __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,             \
480    __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))   \
481      (hptr)), (void)0)
482 
483 #ifdef TARGET_WORDS_BIGENDIAN
484 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
485 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
486 #else
487 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
488 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
489 #endif
490 
491 /* put_user()/get_user() take a guest address and check access */
492 /* These are usually used to access an atomic data type, such as an int,
493  * that has been passed by address.  These internally perform locking
494  * and unlocking on the data type.
495  */
496 #define put_user(x, gaddr, target_type)					\
497 ({									\
498     abi_ulong __gaddr = (gaddr);					\
499     target_type *__hptr;						\
500     abi_long __ret = 0;							\
501     if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
502         __put_user((x), __hptr);				\
503         unlock_user(__hptr, __gaddr, sizeof(target_type));		\
504     } else								\
505         __ret = -TARGET_EFAULT;						\
506     __ret;								\
507 })
508 
509 #define get_user(x, gaddr, target_type)					\
510 ({									\
511     abi_ulong __gaddr = (gaddr);					\
512     target_type *__hptr;						\
513     abi_long __ret = 0;							\
514     if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
515         __get_user((x), __hptr);				\
516         unlock_user(__hptr, __gaddr, 0);				\
517     } else {								\
518         /* avoid warning */						\
519         (x) = 0;							\
520         __ret = -TARGET_EFAULT;						\
521     }									\
522     __ret;								\
523 })
524 
525 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
526 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
527 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
528 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
529 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
530 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
531 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
532 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
533 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
534 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
535 
536 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
537 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
538 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
539 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
540 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
541 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
542 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
543 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
544 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
545 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
546 
547 /* copy_from_user() and copy_to_user() are usually used to copy data
548  * buffers between the target and host.  These internally perform
549  * locking/unlocking of the memory.
550  */
551 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
552 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
553 
554 /* Functions for accessing guest memory.  The tget and tput functions
555    read/write single values, byteswapping as necessary.  The lock_user function
556    gets a pointer to a contiguous area of guest memory, but does not perform
557    any byteswapping.  lock_user may return either a pointer to the guest
558    memory, or a temporary buffer.  */
559 
560 /* Lock an area of guest memory into the host.  If copy is true then the
561    host area will have the same contents as the guest.  */
562 static inline void *lock_user(int type, abi_ulong guest_addr, long len, int copy)
563 {
564     if (!access_ok(type, guest_addr, len))
565         return NULL;
566 #ifdef DEBUG_REMAP
567     {
568         void *addr;
569         addr = g_malloc(len);
570         if (copy)
571             memcpy(addr, g2h(guest_addr), len);
572         else
573             memset(addr, 0, len);
574         return addr;
575     }
576 #else
577     return g2h(guest_addr);
578 #endif
579 }
580 
581 /* Unlock an area of guest memory.  The first LEN bytes must be
582    flushed back to guest memory. host_ptr = NULL is explicitly
583    allowed and does nothing. */
584 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
585                                long len)
586 {
587 
588 #ifdef DEBUG_REMAP
589     if (!host_ptr)
590         return;
591     if (host_ptr == g2h(guest_addr))
592         return;
593     if (len > 0)
594         memcpy(g2h(guest_addr), host_ptr, len);
595     g_free(host_ptr);
596 #endif
597 }
598 
599 /* Return the length of a string in target memory or -TARGET_EFAULT if
600    access error. */
601 abi_long target_strlen(abi_ulong gaddr);
602 
603 /* Like lock_user but for null terminated strings.  */
604 static inline void *lock_user_string(abi_ulong guest_addr)
605 {
606     abi_long len;
607     len = target_strlen(guest_addr);
608     if (len < 0)
609         return NULL;
610     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
611 }
612 
613 /* Helper macros for locking/unlocking a target struct.  */
614 #define lock_user_struct(type, host_ptr, guest_addr, copy)	\
615     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
616 #define unlock_user_struct(host_ptr, guest_addr, copy)		\
617     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
618 
619 #include <pthread.h>
620 
621 static inline int is_error(abi_long ret)
622 {
623     return (abi_ulong)ret >= (abi_ulong)(-4096);
624 }
625 
626 /* Include target-specific struct and function definitions;
627  * they may need access to the target-independent structures
628  * above, so include them last.
629  */
630 #include "target_cpu.h"
631 #include "target_structs.h"
632 
633 #endif /* QEMU_H */
634