xref: /openbmc/qemu/linux-user/qemu.h (revision ddda3748)
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 
20 /* This is the size of the host kernel's sigset_t, needed where we make
21  * direct system calls that take a sigset_t pointer and a size.
22  */
23 #define SIGSET_T_SIZE (_NSIG / 8)
24 
25 /* This struct is used to hold certain information about the image.
26  * Basically, it replicates in user space what would be certain
27  * task_struct fields in the kernel
28  */
29 struct image_info {
30         abi_ulong       load_bias;
31         abi_ulong       load_addr;
32         abi_ulong       start_code;
33         abi_ulong       end_code;
34         abi_ulong       start_data;
35         abi_ulong       end_data;
36         abi_ulong       start_brk;
37         abi_ulong       brk;
38         abi_ulong       reserve_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         abi_ulong       alignment;
55 
56         /* The fields below are used in FDPIC mode.  */
57         abi_ulong       loadmap_addr;
58         uint16_t        nsegs;
59         void           *loadsegs;
60         abi_ulong       pt_dynamic_addr;
61         abi_ulong       interpreter_loadmap_addr;
62         abi_ulong       interpreter_pt_dynamic_addr;
63         struct image_info *other_info;
64 #ifdef TARGET_MIPS
65         int             fp_abi;
66         int             interp_fp_abi;
67 #endif
68 };
69 
70 #ifdef TARGET_I386
71 /* Information about the current linux thread */
72 struct vm86_saved_state {
73     uint32_t eax; /* return code */
74     uint32_t ebx;
75     uint32_t ecx;
76     uint32_t edx;
77     uint32_t esi;
78     uint32_t edi;
79     uint32_t ebp;
80     uint32_t esp;
81     uint32_t eflags;
82     uint32_t eip;
83     uint16_t cs, ss, ds, es, fs, gs;
84 };
85 #endif
86 
87 #if defined(TARGET_ARM) && defined(TARGET_ABI32)
88 /* FPU emulator */
89 #include "nwfpe/fpa11.h"
90 #endif
91 
92 #define MAX_SIGQUEUE_SIZE 1024
93 
94 struct emulated_sigtable {
95     int pending; /* true if signal is pending */
96     target_siginfo_t info;
97 };
98 
99 /* NOTE: we force a big alignment so that the stack stored after is
100    aligned too */
101 typedef struct TaskState {
102     pid_t ts_tid;     /* tid (or pid) of this task */
103 #ifdef TARGET_ARM
104 # ifdef TARGET_ABI32
105     /* FPA state */
106     FPA11 fpa;
107 # endif
108     int swi_errno;
109 #endif
110 #if defined(TARGET_I386) && !defined(TARGET_X86_64)
111     abi_ulong target_v86;
112     struct vm86_saved_state vm86_saved_regs;
113     struct target_vm86plus_struct vm86plus;
114     uint32_t v86flags;
115     uint32_t v86mask;
116 #endif
117     abi_ulong child_tidptr;
118 #ifdef TARGET_M68K
119     abi_ulong tp_value;
120 #endif
121 #if defined(TARGET_ARM) || defined(TARGET_M68K)
122     /* Extra fields for semihosted binaries.  */
123     abi_ulong heap_base;
124     abi_ulong heap_limit;
125 #endif
126     abi_ulong stack_base;
127     int used; /* non zero if used */
128     struct image_info *info;
129     struct linux_binprm *bprm;
130 
131     struct emulated_sigtable sync_signal;
132     struct emulated_sigtable sigtab[TARGET_NSIG];
133     /* This thread's signal mask, as requested by the guest program.
134      * The actual signal mask of this thread may differ:
135      *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
136      *  + sometimes we block all signals to avoid races
137      */
138     sigset_t signal_mask;
139     /* The signal mask imposed by a guest sigsuspend syscall, if we are
140      * currently in the middle of such a syscall
141      */
142     sigset_t sigsuspend_mask;
143     /* Nonzero if we're leaving a sigsuspend and sigsuspend_mask is valid. */
144     int in_sigsuspend;
145 
146     /* Nonzero if process_pending_signals() needs to do something (either
147      * handle a pending signal or unblock signals).
148      * This flag is written from a signal handler so should be accessed via
149      * the atomic_read() and atomic_set() functions. (It is not accessed
150      * from multiple threads.)
151      */
152     int signal_pending;
153 
154     /* This thread's sigaltstack, if it has one */
155     struct target_sigaltstack sigaltstack_used;
156 } __attribute__((aligned(16))) TaskState;
157 
158 extern char *exec_path;
159 void init_task_state(TaskState *ts);
160 void task_settid(TaskState *);
161 void stop_all_tasks(void);
162 extern const char *qemu_uname_release;
163 extern unsigned long mmap_min_addr;
164 
165 /* ??? See if we can avoid exposing so much of the loader internals.  */
166 
167 /* Read a good amount of data initially, to hopefully get all the
168    program headers loaded.  */
169 #define BPRM_BUF_SIZE  1024
170 
171 /*
172  * This structure is used to hold the arguments that are
173  * used when loading binaries.
174  */
175 struct linux_binprm {
176         char buf[BPRM_BUF_SIZE] __attribute__((aligned));
177         abi_ulong p;
178         int fd;
179         int e_uid, e_gid;
180         int argc, envc;
181         char **argv;
182         char **envp;
183         char * filename;        /* Name of binary */
184         int (*core_dump)(int, const CPUArchState *); /* coredump routine */
185 };
186 
187 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
188 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
189                               abi_ulong stringp, int push_ptr);
190 int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
191              struct target_pt_regs * regs, struct image_info *infop,
192              struct linux_binprm *);
193 
194 /* Returns true if the image uses the FDPIC ABI. If this is the case,
195  * we have to provide some information (loadmap, pt_dynamic_info) such
196  * that the program can be relocated adequately. This is also useful
197  * when handling signals.
198  */
199 int info_is_fdpic(struct image_info *info);
200 
201 uint32_t get_elf_eflags(int fd);
202 int load_elf_binary(struct linux_binprm *bprm, struct image_info *info);
203 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info);
204 
205 abi_long memcpy_to_target(abi_ulong dest, const void *src,
206                           unsigned long len);
207 void target_set_brk(abi_ulong new_brk);
208 abi_long do_brk(abi_ulong new_brk);
209 void syscall_init(void);
210 abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
211                     abi_long arg2, abi_long arg3, abi_long arg4,
212                     abi_long arg5, abi_long arg6, abi_long arg7,
213                     abi_long arg8);
214 extern __thread CPUState *thread_cpu;
215 void cpu_loop(CPUArchState *env);
216 const char *target_strerror(int err);
217 int get_osversion(void);
218 void init_qemu_uname_release(void);
219 void fork_start(void);
220 void fork_end(int child);
221 
222 /* Creates the initial guest address space in the host memory space using
223  * the given host start address hint and size.  The guest_start parameter
224  * specifies the start address of the guest space.  guest_base will be the
225  * difference between the host start address computed by this function and
226  * guest_start.  If fixed is specified, then the mapped address space must
227  * start at host_start.  The real start address of the mapped memory space is
228  * returned or -1 if there was an error.
229  */
230 unsigned long init_guest_space(unsigned long host_start,
231                                unsigned long host_size,
232                                unsigned long guest_start,
233                                bool fixed);
234 
235 #include "qemu/log.h"
236 
237 /* safe_syscall.S */
238 
239 /**
240  * safe_syscall:
241  * @int number: number of system call to make
242  * ...: arguments to the system call
243  *
244  * Call a system call if guest signal not pending.
245  * This has the same API as the libc syscall() function, except that it
246  * may return -1 with errno == TARGET_ERESTARTSYS if a signal was pending.
247  *
248  * Returns: the system call result, or -1 with an error code in errno
249  * (Errnos are host errnos; we rely on TARGET_ERESTARTSYS not clashing
250  * with any of the host errno values.)
251  */
252 
253 /* A guide to using safe_syscall() to handle interactions between guest
254  * syscalls and guest signals:
255  *
256  * Guest syscalls come in two flavours:
257  *
258  * (1) Non-interruptible syscalls
259  *
260  * These are guest syscalls that never get interrupted by signals and
261  * so never return EINTR. They can be implemented straightforwardly in
262  * QEMU: just make sure that if the implementation code has to make any
263  * blocking calls that those calls are retried if they return EINTR.
264  * It's also OK to implement these with safe_syscall, though it will be
265  * a little less efficient if a signal is delivered at the 'wrong' moment.
266  *
267  * Some non-interruptible syscalls need to be handled using block_signals()
268  * to block signals for the duration of the syscall. This mainly applies
269  * to code which needs to modify the data structures used by the
270  * host_signal_handler() function and the functions it calls, including
271  * all syscalls which change the thread's signal mask.
272  *
273  * (2) Interruptible syscalls
274  *
275  * These are guest syscalls that can be interrupted by signals and
276  * for which we need to either return EINTR or arrange for the guest
277  * syscall to be restarted. This category includes both syscalls which
278  * always restart (and in the kernel return -ERESTARTNOINTR), ones
279  * which only restart if there is no handler (kernel returns -ERESTARTNOHAND
280  * or -ERESTART_RESTARTBLOCK), and the most common kind which restart
281  * if the handler was registered with SA_RESTART (kernel returns
282  * -ERESTARTSYS). System calls which are only interruptible in some
283  * situations (like 'open') also need to be handled this way.
284  *
285  * Here it is important that the host syscall is made
286  * via this safe_syscall() function, and *not* via the host libc.
287  * If the host libc is used then the implementation will appear to work
288  * most of the time, but there will be a race condition where a
289  * signal could arrive just before we make the host syscall inside libc,
290  * and then then guest syscall will not correctly be interrupted.
291  * Instead the implementation of the guest syscall can use the safe_syscall
292  * function but otherwise just return the result or errno in the usual
293  * way; the main loop code will take care of restarting the syscall
294  * if appropriate.
295  *
296  * (If the implementation needs to make multiple host syscalls this is
297  * OK; any which might really block must be via safe_syscall(); for those
298  * which are only technically blocking (ie which we know in practice won't
299  * stay in the host kernel indefinitely) it's OK to use libc if necessary.
300  * You must be able to cope with backing out correctly if some safe_syscall
301  * you make in the implementation returns either -TARGET_ERESTARTSYS or
302  * EINTR though.)
303  *
304  * block_signals() cannot be used for interruptible syscalls.
305  *
306  *
307  * How and why the safe_syscall implementation works:
308  *
309  * The basic setup is that we make the host syscall via a known
310  * section of host native assembly. If a signal occurs, our signal
311  * handler checks the interrupted host PC against the addresse of that
312  * known section. If the PC is before or at the address of the syscall
313  * instruction then we change the PC to point at a "return
314  * -TARGET_ERESTARTSYS" code path instead, and then exit the signal handler
315  * (causing the safe_syscall() call to immediately return that value).
316  * Then in the main.c loop if we see this magic return value we adjust
317  * the guest PC to wind it back to before the system call, and invoke
318  * the guest signal handler as usual.
319  *
320  * This winding-back will happen in two cases:
321  * (1) signal came in just before we took the host syscall (a race);
322  *   in this case we'll take the guest signal and have another go
323  *   at the syscall afterwards, and this is indistinguishable for the
324  *   guest from the timing having been different such that the guest
325  *   signal really did win the race
326  * (2) signal came in while the host syscall was blocking, and the
327  *   host kernel decided the syscall should be restarted;
328  *   in this case we want to restart the guest syscall also, and so
329  *   rewinding is the right thing. (Note that "restart" semantics mean
330  *   "first call the signal handler, then reattempt the syscall".)
331  * The other situation to consider is when a signal came in while the
332  * host syscall was blocking, and the host kernel decided that the syscall
333  * should not be restarted; in this case QEMU's host signal handler will
334  * be invoked with the PC pointing just after the syscall instruction,
335  * with registers indicating an EINTR return; the special code in the
336  * handler will not kick in, and we will return EINTR to the guest as
337  * we should.
338  *
339  * Notice that we can leave the host kernel to make the decision for
340  * us about whether to do a restart of the syscall or not; we do not
341  * need to check SA_RESTART flags in QEMU or distinguish the various
342  * kinds of restartability.
343  */
344 #ifdef HAVE_SAFE_SYSCALL
345 /* The core part of this function is implemented in assembly */
346 extern long safe_syscall_base(int *pending, long number, ...);
347 
348 #define safe_syscall(...)                                               \
349     ({                                                                  \
350         long ret_;                                                      \
351         int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \
352         ret_ = safe_syscall_base(psp_, __VA_ARGS__);                    \
353         if (is_error(ret_)) {                                           \
354             errno = -ret_;                                              \
355             ret_ = -1;                                                  \
356         }                                                               \
357         ret_;                                                           \
358     })
359 
360 #else
361 
362 /* Fallback for architectures which don't yet provide a safe-syscall assembly
363  * fragment; note that this is racy!
364  * This should go away when all host architectures have been updated.
365  */
366 #define safe_syscall syscall
367 
368 #endif
369 
370 /* syscall.c */
371 int host_to_target_waitstatus(int status);
372 
373 /* strace.c */
374 void print_syscall(int num,
375                    abi_long arg1, abi_long arg2, abi_long arg3,
376                    abi_long arg4, abi_long arg5, abi_long arg6);
377 void print_syscall_ret(int num, abi_long arg1);
378 /**
379  * print_taken_signal:
380  * @target_signum: target signal being taken
381  * @tinfo: target_siginfo_t which will be passed to the guest for the signal
382  *
383  * Print strace output indicating that this signal is being taken by the guest,
384  * in a format similar to:
385  * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
386  */
387 void print_taken_signal(int target_signum, const target_siginfo_t *tinfo);
388 
389 /* signal.c */
390 void process_pending_signals(CPUArchState *cpu_env);
391 void signal_init(void);
392 int queue_signal(CPUArchState *env, int sig, int si_type,
393                  target_siginfo_t *info);
394 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info);
395 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo);
396 int target_to_host_signal(int sig);
397 int host_to_target_signal(int sig);
398 long do_sigreturn(CPUArchState *env);
399 long do_rt_sigreturn(CPUArchState *env);
400 abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp);
401 int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset);
402 abi_long do_swapcontext(CPUArchState *env, abi_ulong uold_ctx,
403                         abi_ulong unew_ctx, abi_long ctx_size);
404 /**
405  * block_signals: block all signals while handling this guest syscall
406  *
407  * Block all signals, and arrange that the signal mask is returned to
408  * its correct value for the guest before we resume execution of guest code.
409  * If this function returns non-zero, then the caller should immediately
410  * return -TARGET_ERESTARTSYS to the main loop, which will take the pending
411  * signal and restart execution of the syscall.
412  * If block_signals() returns zero, then the caller can continue with
413  * emulation of the system call knowing that no signals can be taken
414  * (and therefore that no race conditions will result).
415  * This should only be called once, because if it is called a second time
416  * it will always return non-zero. (Think of it like a mutex that can't
417  * be recursively locked.)
418  * Signals will be unblocked again by process_pending_signals().
419  *
420  * Return value: non-zero if there was a pending signal, zero if not.
421  */
422 int block_signals(void); /* Returns non zero if signal pending */
423 
424 #ifdef TARGET_I386
425 /* vm86.c */
426 void save_v86_state(CPUX86State *env);
427 void handle_vm86_trap(CPUX86State *env, int trapno);
428 void handle_vm86_fault(CPUX86State *env);
429 int do_vm86(CPUX86State *env, long subfunction, abi_ulong v86_addr);
430 #elif defined(TARGET_SPARC64)
431 void sparc64_set_context(CPUSPARCState *env);
432 void sparc64_get_context(CPUSPARCState *env);
433 #endif
434 
435 /* mmap.c */
436 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
437 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
438                      int flags, int fd, abi_ulong offset);
439 int target_munmap(abi_ulong start, abi_ulong len);
440 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
441                        abi_ulong new_size, unsigned long flags,
442                        abi_ulong new_addr);
443 extern unsigned long last_brk;
444 extern abi_ulong mmap_next_start;
445 abi_ulong mmap_find_vma(abi_ulong, abi_ulong, abi_ulong);
446 void mmap_fork_start(void);
447 void mmap_fork_end(int child);
448 
449 /* main.c */
450 extern unsigned long guest_stack_size;
451 
452 /* user access */
453 
454 #define VERIFY_READ 0
455 #define VERIFY_WRITE 1 /* implies read access */
456 
457 static inline int access_ok(int type, abi_ulong addr, abi_ulong size)
458 {
459     return guest_addr_valid(addr) &&
460            (size == 0 || guest_addr_valid(addr + size - 1)) &&
461            page_check_range((target_ulong)addr, size,
462                             (type == VERIFY_READ) ? PAGE_READ : (PAGE_READ | PAGE_WRITE)) == 0;
463 }
464 
465 /* NOTE __get_user and __put_user use host pointers and don't check access.
466    These are usually used to access struct data members once the struct has
467    been locked - usually with lock_user_struct.  */
468 
469 /*
470  * Tricky points:
471  * - Use __builtin_choose_expr to avoid type promotion from ?:,
472  * - Invalid sizes result in a compile time error stemming from
473  *   the fact that abort has no parameters.
474  * - It's easier to use the endian-specific unaligned load/store
475  *   functions than host-endian unaligned load/store plus tswapN.
476  * - The pragmas are necessary only to silence a clang false-positive
477  *   warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
478  * - gcc has bugs in its _Pragma() support in some versions, eg
479  *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
480  *   include the warning-suppression pragmas for clang
481  */
482 #if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
483 #define PRAGMA_DISABLE_PACKED_WARNING                                   \
484     _Pragma("GCC diagnostic push");                                     \
485     _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")
486 
487 #define PRAGMA_REENABLE_PACKED_WARNING          \
488     _Pragma("GCC diagnostic pop")
489 
490 #else
491 #define PRAGMA_DISABLE_PACKED_WARNING
492 #define PRAGMA_REENABLE_PACKED_WARNING
493 #endif
494 
495 #define __put_user_e(x, hptr, e)                                            \
496     do {                                                                    \
497         PRAGMA_DISABLE_PACKED_WARNING;                                      \
498         (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                 \
499         __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,            \
500         __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,            \
501         __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))  \
502             ((hptr), (x)), (void)0);                                        \
503         PRAGMA_REENABLE_PACKED_WARNING;                                     \
504     } while (0)
505 
506 #define __get_user_e(x, hptr, e)                                            \
507     do {                                                                    \
508         PRAGMA_DISABLE_PACKED_WARNING;                                      \
509         ((x) = (typeof(*hptr))(                                             \
510         __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                 \
511         __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,           \
512         __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,            \
513         __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))  \
514             (hptr)), (void)0);                                              \
515         PRAGMA_REENABLE_PACKED_WARNING;                                     \
516     } while (0)
517 
518 
519 #ifdef TARGET_WORDS_BIGENDIAN
520 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
521 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
522 #else
523 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
524 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
525 #endif
526 
527 /* put_user()/get_user() take a guest address and check access */
528 /* These are usually used to access an atomic data type, such as an int,
529  * that has been passed by address.  These internally perform locking
530  * and unlocking on the data type.
531  */
532 #define put_user(x, gaddr, target_type)					\
533 ({									\
534     abi_ulong __gaddr = (gaddr);					\
535     target_type *__hptr;						\
536     abi_long __ret = 0;							\
537     if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
538         __put_user((x), __hptr);				\
539         unlock_user(__hptr, __gaddr, sizeof(target_type));		\
540     } else								\
541         __ret = -TARGET_EFAULT;						\
542     __ret;								\
543 })
544 
545 #define get_user(x, gaddr, target_type)					\
546 ({									\
547     abi_ulong __gaddr = (gaddr);					\
548     target_type *__hptr;						\
549     abi_long __ret = 0;							\
550     if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
551         __get_user((x), __hptr);				\
552         unlock_user(__hptr, __gaddr, 0);				\
553     } else {								\
554         /* avoid warning */						\
555         (x) = 0;							\
556         __ret = -TARGET_EFAULT;						\
557     }									\
558     __ret;								\
559 })
560 
561 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
562 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
563 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
564 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
565 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
566 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
567 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
568 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
569 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
570 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
571 
572 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
573 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
574 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
575 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
576 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
577 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
578 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
579 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
580 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
581 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
582 
583 /* copy_from_user() and copy_to_user() are usually used to copy data
584  * buffers between the target and host.  These internally perform
585  * locking/unlocking of the memory.
586  */
587 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
588 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
589 
590 /* Functions for accessing guest memory.  The tget and tput functions
591    read/write single values, byteswapping as necessary.  The lock_user function
592    gets a pointer to a contiguous area of guest memory, but does not perform
593    any byteswapping.  lock_user may return either a pointer to the guest
594    memory, or a temporary buffer.  */
595 
596 /* Lock an area of guest memory into the host.  If copy is true then the
597    host area will have the same contents as the guest.  */
598 static inline void *lock_user(int type, abi_ulong guest_addr, long len, int copy)
599 {
600     if (!access_ok(type, guest_addr, len))
601         return NULL;
602 #ifdef DEBUG_REMAP
603     {
604         void *addr;
605         addr = g_malloc(len);
606         if (copy)
607             memcpy(addr, g2h(guest_addr), len);
608         else
609             memset(addr, 0, len);
610         return addr;
611     }
612 #else
613     return g2h(guest_addr);
614 #endif
615 }
616 
617 /* Unlock an area of guest memory.  The first LEN bytes must be
618    flushed back to guest memory. host_ptr = NULL is explicitly
619    allowed and does nothing. */
620 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
621                                long len)
622 {
623 
624 #ifdef DEBUG_REMAP
625     if (!host_ptr)
626         return;
627     if (host_ptr == g2h(guest_addr))
628         return;
629     if (len > 0)
630         memcpy(g2h(guest_addr), host_ptr, len);
631     g_free(host_ptr);
632 #endif
633 }
634 
635 /* Return the length of a string in target memory or -TARGET_EFAULT if
636    access error. */
637 abi_long target_strlen(abi_ulong gaddr);
638 
639 /* Like lock_user but for null terminated strings.  */
640 static inline void *lock_user_string(abi_ulong guest_addr)
641 {
642     abi_long len;
643     len = target_strlen(guest_addr);
644     if (len < 0)
645         return NULL;
646     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
647 }
648 
649 /* Helper macros for locking/unlocking a target struct.  */
650 #define lock_user_struct(type, host_ptr, guest_addr, copy)	\
651     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
652 #define unlock_user_struct(host_ptr, guest_addr, copy)		\
653     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
654 
655 #include <pthread.h>
656 
657 static inline int is_error(abi_long ret)
658 {
659     return (abi_ulong)ret >= (abi_ulong)(-4096);
660 }
661 
662 /**
663  * preexit_cleanup: housekeeping before the guest exits
664  *
665  * env: the CPU state
666  * code: the exit code
667  */
668 void preexit_cleanup(CPUArchState *env, int code);
669 
670 /* Include target-specific struct and function definitions;
671  * they may need access to the target-independent structures
672  * above, so include them last.
673  */
674 #include "target_cpu.h"
675 #include "target_structs.h"
676 
677 #endif /* QEMU_H */
678