xref: /openbmc/qemu/linux-user/qemu.h (revision 5cc8767d)
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         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 } __attribute__((aligned(16))) TaskState;
155 
156 extern char *exec_path;
157 void init_task_state(TaskState *ts);
158 void task_settid(TaskState *);
159 void stop_all_tasks(void);
160 extern const char *qemu_uname_release;
161 extern unsigned long mmap_min_addr;
162 
163 /* ??? See if we can avoid exposing so much of the loader internals.  */
164 
165 /* Read a good amount of data initially, to hopefully get all the
166    program headers loaded.  */
167 #define BPRM_BUF_SIZE  1024
168 
169 /*
170  * This structure is used to hold the arguments that are
171  * used when loading binaries.
172  */
173 struct linux_binprm {
174         char buf[BPRM_BUF_SIZE] __attribute__((aligned));
175         abi_ulong p;
176         int fd;
177         int e_uid, e_gid;
178         int argc, envc;
179         char **argv;
180         char **envp;
181         char * filename;        /* Name of binary */
182         int (*core_dump)(int, const CPUArchState *); /* coredump routine */
183 };
184 
185 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
186 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
187                               abi_ulong stringp, int push_ptr);
188 int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
189              struct target_pt_regs * regs, struct image_info *infop,
190              struct linux_binprm *);
191 
192 /* Returns true if the image uses the FDPIC ABI. If this is the case,
193  * we have to provide some information (loadmap, pt_dynamic_info) such
194  * that the program can be relocated adequately. This is also useful
195  * when handling signals.
196  */
197 int info_is_fdpic(struct image_info *info);
198 
199 uint32_t get_elf_eflags(int fd);
200 int load_elf_binary(struct linux_binprm *bprm, struct image_info *info);
201 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info);
202 
203 abi_long memcpy_to_target(abi_ulong dest, const void *src,
204                           unsigned long len);
205 void target_set_brk(abi_ulong new_brk);
206 abi_long do_brk(abi_ulong new_brk);
207 void syscall_init(void);
208 abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
209                     abi_long arg2, abi_long arg3, abi_long arg4,
210                     abi_long arg5, abi_long arg6, abi_long arg7,
211                     abi_long arg8);
212 void gemu_log(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
213 extern __thread CPUState *thread_cpu;
214 void cpu_loop(CPUArchState *env);
215 const char *target_strerror(int err);
216 int get_osversion(void);
217 void init_qemu_uname_release(void);
218 void fork_start(void);
219 void fork_end(int child);
220 
221 /* Creates the initial guest address space in the host memory space using
222  * the given host start address hint and size.  The guest_start parameter
223  * specifies the start address of the guest space.  guest_base will be the
224  * difference between the host start address computed by this function and
225  * guest_start.  If fixed is specified, then the mapped address space must
226  * start at host_start.  The real start address of the mapped memory space is
227  * returned or -1 if there was an error.
228  */
229 unsigned long init_guest_space(unsigned long host_start,
230                                unsigned long host_size,
231                                unsigned long guest_start,
232                                bool fixed);
233 
234 #include "qemu/log.h"
235 
236 /* safe_syscall.S */
237 
238 /**
239  * safe_syscall:
240  * @int number: number of system call to make
241  * ...: arguments to the system call
242  *
243  * Call a system call if guest signal not pending.
244  * This has the same API as the libc syscall() function, except that it
245  * may return -1 with errno == TARGET_ERESTARTSYS if a signal was pending.
246  *
247  * Returns: the system call result, or -1 with an error code in errno
248  * (Errnos are host errnos; we rely on TARGET_ERESTARTSYS not clashing
249  * with any of the host errno values.)
250  */
251 
252 /* A guide to using safe_syscall() to handle interactions between guest
253  * syscalls and guest signals:
254  *
255  * Guest syscalls come in two flavours:
256  *
257  * (1) Non-interruptible syscalls
258  *
259  * These are guest syscalls that never get interrupted by signals and
260  * so never return EINTR. They can be implemented straightforwardly in
261  * QEMU: just make sure that if the implementation code has to make any
262  * blocking calls that those calls are retried if they return EINTR.
263  * It's also OK to implement these with safe_syscall, though it will be
264  * a little less efficient if a signal is delivered at the 'wrong' moment.
265  *
266  * Some non-interruptible syscalls need to be handled using block_signals()
267  * to block signals for the duration of the syscall. This mainly applies
268  * to code which needs to modify the data structures used by the
269  * host_signal_handler() function and the functions it calls, including
270  * all syscalls which change the thread's signal mask.
271  *
272  * (2) Interruptible syscalls
273  *
274  * These are guest syscalls that can be interrupted by signals and
275  * for which we need to either return EINTR or arrange for the guest
276  * syscall to be restarted. This category includes both syscalls which
277  * always restart (and in the kernel return -ERESTARTNOINTR), ones
278  * which only restart if there is no handler (kernel returns -ERESTARTNOHAND
279  * or -ERESTART_RESTARTBLOCK), and the most common kind which restart
280  * if the handler was registered with SA_RESTART (kernel returns
281  * -ERESTARTSYS). System calls which are only interruptible in some
282  * situations (like 'open') also need to be handled this way.
283  *
284  * Here it is important that the host syscall is made
285  * via this safe_syscall() function, and *not* via the host libc.
286  * If the host libc is used then the implementation will appear to work
287  * most of the time, but there will be a race condition where a
288  * signal could arrive just before we make the host syscall inside libc,
289  * and then then guest syscall will not correctly be interrupted.
290  * Instead the implementation of the guest syscall can use the safe_syscall
291  * function but otherwise just return the result or errno in the usual
292  * way; the main loop code will take care of restarting the syscall
293  * if appropriate.
294  *
295  * (If the implementation needs to make multiple host syscalls this is
296  * OK; any which might really block must be via safe_syscall(); for those
297  * which are only technically blocking (ie which we know in practice won't
298  * stay in the host kernel indefinitely) it's OK to use libc if necessary.
299  * You must be able to cope with backing out correctly if some safe_syscall
300  * you make in the implementation returns either -TARGET_ERESTARTSYS or
301  * EINTR though.)
302  *
303  * block_signals() cannot be used for interruptible syscalls.
304  *
305  *
306  * How and why the safe_syscall implementation works:
307  *
308  * The basic setup is that we make the host syscall via a known
309  * section of host native assembly. If a signal occurs, our signal
310  * handler checks the interrupted host PC against the addresse of that
311  * known section. If the PC is before or at the address of the syscall
312  * instruction then we change the PC to point at a "return
313  * -TARGET_ERESTARTSYS" code path instead, and then exit the signal handler
314  * (causing the safe_syscall() call to immediately return that value).
315  * Then in the main.c loop if we see this magic return value we adjust
316  * the guest PC to wind it back to before the system call, and invoke
317  * the guest signal handler as usual.
318  *
319  * This winding-back will happen in two cases:
320  * (1) signal came in just before we took the host syscall (a race);
321  *   in this case we'll take the guest signal and have another go
322  *   at the syscall afterwards, and this is indistinguishable for the
323  *   guest from the timing having been different such that the guest
324  *   signal really did win the race
325  * (2) signal came in while the host syscall was blocking, and the
326  *   host kernel decided the syscall should be restarted;
327  *   in this case we want to restart the guest syscall also, and so
328  *   rewinding is the right thing. (Note that "restart" semantics mean
329  *   "first call the signal handler, then reattempt the syscall".)
330  * The other situation to consider is when a signal came in while the
331  * host syscall was blocking, and the host kernel decided that the syscall
332  * should not be restarted; in this case QEMU's host signal handler will
333  * be invoked with the PC pointing just after the syscall instruction,
334  * with registers indicating an EINTR return; the special code in the
335  * handler will not kick in, and we will return EINTR to the guest as
336  * we should.
337  *
338  * Notice that we can leave the host kernel to make the decision for
339  * us about whether to do a restart of the syscall or not; we do not
340  * need to check SA_RESTART flags in QEMU or distinguish the various
341  * kinds of restartability.
342  */
343 #ifdef HAVE_SAFE_SYSCALL
344 /* The core part of this function is implemented in assembly */
345 extern long safe_syscall_base(int *pending, long number, ...);
346 
347 #define safe_syscall(...)                                               \
348     ({                                                                  \
349         long ret_;                                                      \
350         int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \
351         ret_ = safe_syscall_base(psp_, __VA_ARGS__);                    \
352         if (is_error(ret_)) {                                           \
353             errno = -ret_;                                              \
354             ret_ = -1;                                                  \
355         }                                                               \
356         ret_;                                                           \
357     })
358 
359 #else
360 
361 /* Fallback for architectures which don't yet provide a safe-syscall assembly
362  * fragment; note that this is racy!
363  * This should go away when all host architectures have been updated.
364  */
365 #define safe_syscall syscall
366 
367 #endif
368 
369 /* syscall.c */
370 int host_to_target_waitstatus(int status);
371 
372 /* strace.c */
373 void print_syscall(int num,
374                    abi_long arg1, abi_long arg2, abi_long arg3,
375                    abi_long arg4, abi_long arg5, abi_long arg6);
376 void print_syscall_ret(int num, abi_long arg1);
377 /**
378  * print_taken_signal:
379  * @target_signum: target signal being taken
380  * @tinfo: target_siginfo_t which will be passed to the guest for the signal
381  *
382  * Print strace output indicating that this signal is being taken by the guest,
383  * in a format similar to:
384  * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
385  */
386 void print_taken_signal(int target_signum, const target_siginfo_t *tinfo);
387 extern int do_strace;
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 page_check_range((target_ulong)addr, size,
460                             (type == VERIFY_READ) ? PAGE_READ : (PAGE_READ | PAGE_WRITE)) == 0;
461 }
462 
463 /* NOTE __get_user and __put_user use host pointers and don't check access.
464    These are usually used to access struct data members once the struct has
465    been locked - usually with lock_user_struct.  */
466 
467 /*
468  * Tricky points:
469  * - Use __builtin_choose_expr to avoid type promotion from ?:,
470  * - Invalid sizes result in a compile time error stemming from
471  *   the fact that abort has no parameters.
472  * - It's easier to use the endian-specific unaligned load/store
473  *   functions than host-endian unaligned load/store plus tswapN.
474  * - The pragmas are necessary only to silence a clang false-positive
475  *   warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
476  * - gcc has bugs in its _Pragma() support in some versions, eg
477  *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
478  *   include the warning-suppression pragmas for clang
479  */
480 #if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
481 #define PRAGMA_DISABLE_PACKED_WARNING                                   \
482     _Pragma("GCC diagnostic push");                                     \
483     _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")
484 
485 #define PRAGMA_REENABLE_PACKED_WARNING          \
486     _Pragma("GCC diagnostic pop")
487 
488 #else
489 #define PRAGMA_DISABLE_PACKED_WARNING
490 #define PRAGMA_REENABLE_PACKED_WARNING
491 #endif
492 
493 #define __put_user_e(x, hptr, e)                                            \
494     do {                                                                    \
495         PRAGMA_DISABLE_PACKED_WARNING;                                      \
496         (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                 \
497         __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,            \
498         __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,            \
499         __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))  \
500             ((hptr), (x)), (void)0);                                        \
501         PRAGMA_REENABLE_PACKED_WARNING;                                     \
502     } while (0)
503 
504 #define __get_user_e(x, hptr, e)                                            \
505     do {                                                                    \
506         PRAGMA_DISABLE_PACKED_WARNING;                                      \
507         ((x) = (typeof(*hptr))(                                             \
508         __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                 \
509         __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,           \
510         __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,            \
511         __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))  \
512             (hptr)), (void)0);                                              \
513         PRAGMA_REENABLE_PACKED_WARNING;                                     \
514     } while (0)
515 
516 
517 #ifdef TARGET_WORDS_BIGENDIAN
518 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
519 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
520 #else
521 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
522 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
523 #endif
524 
525 /* put_user()/get_user() take a guest address and check access */
526 /* These are usually used to access an atomic data type, such as an int,
527  * that has been passed by address.  These internally perform locking
528  * and unlocking on the data type.
529  */
530 #define put_user(x, gaddr, target_type)					\
531 ({									\
532     abi_ulong __gaddr = (gaddr);					\
533     target_type *__hptr;						\
534     abi_long __ret = 0;							\
535     if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
536         __put_user((x), __hptr);				\
537         unlock_user(__hptr, __gaddr, sizeof(target_type));		\
538     } else								\
539         __ret = -TARGET_EFAULT;						\
540     __ret;								\
541 })
542 
543 #define get_user(x, gaddr, target_type)					\
544 ({									\
545     abi_ulong __gaddr = (gaddr);					\
546     target_type *__hptr;						\
547     abi_long __ret = 0;							\
548     if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
549         __get_user((x), __hptr);				\
550         unlock_user(__hptr, __gaddr, 0);				\
551     } else {								\
552         /* avoid warning */						\
553         (x) = 0;							\
554         __ret = -TARGET_EFAULT;						\
555     }									\
556     __ret;								\
557 })
558 
559 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
560 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
561 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
562 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
563 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
564 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
565 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
566 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
567 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
568 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
569 
570 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
571 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
572 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
573 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
574 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
575 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
576 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
577 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
578 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
579 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
580 
581 /* copy_from_user() and copy_to_user() are usually used to copy data
582  * buffers between the target and host.  These internally perform
583  * locking/unlocking of the memory.
584  */
585 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
586 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
587 
588 /* Functions for accessing guest memory.  The tget and tput functions
589    read/write single values, byteswapping as necessary.  The lock_user function
590    gets a pointer to a contiguous area of guest memory, but does not perform
591    any byteswapping.  lock_user may return either a pointer to the guest
592    memory, or a temporary buffer.  */
593 
594 /* Lock an area of guest memory into the host.  If copy is true then the
595    host area will have the same contents as the guest.  */
596 static inline void *lock_user(int type, abi_ulong guest_addr, long len, int copy)
597 {
598     if (!access_ok(type, guest_addr, len))
599         return NULL;
600 #ifdef DEBUG_REMAP
601     {
602         void *addr;
603         addr = g_malloc(len);
604         if (copy)
605             memcpy(addr, g2h(guest_addr), len);
606         else
607             memset(addr, 0, len);
608         return addr;
609     }
610 #else
611     return g2h(guest_addr);
612 #endif
613 }
614 
615 /* Unlock an area of guest memory.  The first LEN bytes must be
616    flushed back to guest memory. host_ptr = NULL is explicitly
617    allowed and does nothing. */
618 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
619                                long len)
620 {
621 
622 #ifdef DEBUG_REMAP
623     if (!host_ptr)
624         return;
625     if (host_ptr == g2h(guest_addr))
626         return;
627     if (len > 0)
628         memcpy(g2h(guest_addr), host_ptr, len);
629     g_free(host_ptr);
630 #endif
631 }
632 
633 /* Return the length of a string in target memory or -TARGET_EFAULT if
634    access error. */
635 abi_long target_strlen(abi_ulong gaddr);
636 
637 /* Like lock_user but for null terminated strings.  */
638 static inline void *lock_user_string(abi_ulong guest_addr)
639 {
640     abi_long len;
641     len = target_strlen(guest_addr);
642     if (len < 0)
643         return NULL;
644     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
645 }
646 
647 /* Helper macros for locking/unlocking a target struct.  */
648 #define lock_user_struct(type, host_ptr, guest_addr, copy)	\
649     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
650 #define unlock_user_struct(host_ptr, guest_addr, copy)		\
651     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
652 
653 #include <pthread.h>
654 
655 static inline int is_error(abi_long ret)
656 {
657     return (abi_ulong)ret >= (abi_ulong)(-4096);
658 }
659 
660 /**
661  * preexit_cleanup: housekeeping before the guest exits
662  *
663  * env: the CPU state
664  * code: the exit code
665  */
666 void preexit_cleanup(CPUArchState *env, int code);
667 
668 /* Include target-specific struct and function definitions;
669  * they may need access to the target-independent structures
670  * above, so include them last.
671  */
672 #include "target_cpu.h"
673 #include "target_structs.h"
674 
675 #endif /* QEMU_H */
676