6 #include "exec/exec-all.h"
7 #include "exec/cpu_ldst.h"
11 #endif /* DEBUG_REMAP */
13 #include "exec/user/abitypes.h"
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"
21 #define THREAD __thread
23 /* This struct is used to hold certain information about the image.
24 * Basically, it replicates in user space what would be certain
25 * task_struct fields in the kernel
37 abi_ulong start_stack
;
38 abi_ulong stack_limit
;
40 abi_ulong code_offset
;
41 abi_ulong data_offset
;
48 #ifdef CONFIG_USE_FDPIC
49 abi_ulong loadmap_addr
;
52 abi_ulong pt_dynamic_addr
;
53 struct image_info
*other_info
;
58 /* Information about the current linux thread */
59 struct vm86_saved_state
{
60 uint32_t eax
; /* return code */
70 uint16_t cs
, ss
, ds
, es
, fs
, gs
;
74 #if defined(TARGET_ARM) && defined(TARGET_ABI32)
76 #include "nwfpe/fpa11.h"
79 #define MAX_SIGQUEUE_SIZE 1024
82 struct sigqueue
*next
;
83 target_siginfo_t info
;
86 struct emulated_sigtable
{
87 int pending
; /* true if signal is pending */
88 struct sigqueue
*first
;
89 struct sigqueue info
; /* in order to always have memory for the
90 first signal, we put it here */
93 /* NOTE: we force a big alignment so that the stack stored after is
95 typedef struct TaskState
{
96 pid_t ts_tid
; /* tid (or pid) of this task */
104 #ifdef TARGET_UNICORE32
107 #if defined(TARGET_I386) && !defined(TARGET_X86_64)
108 abi_ulong target_v86
;
109 struct vm86_saved_state vm86_saved_regs
;
110 struct target_vm86plus_struct vm86plus
;
114 abi_ulong child_tidptr
;
119 #if defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_UNICORE32)
120 /* Extra fields for semihosted binaries. */
125 int used
; /* non zero if used */
126 bool sigsegv_blocked
; /* SIGSEGV blocked by guest */
127 struct image_info
*info
;
128 struct linux_binprm
*bprm
;
130 struct emulated_sigtable sigtab
[TARGET_NSIG
];
131 struct sigqueue sigqueue_table
[MAX_SIGQUEUE_SIZE
]; /* siginfo queue */
132 struct sigqueue
*first_free
; /* first free siginfo queue entry */
133 int signal_pending
; /* non zero if a signal may be pending */
134 } __attribute__((aligned(16))) TaskState
;
136 extern char *exec_path
;
137 void init_task_state(TaskState
*ts
);
138 void task_settid(TaskState
*);
139 void stop_all_tasks(void);
140 extern const char *qemu_uname_release
;
141 extern unsigned long mmap_min_addr
;
143 /* ??? See if we can avoid exposing so much of the loader internals. */
145 /* Read a good amount of data initially, to hopefully get all the
146 program headers loaded. */
147 #define BPRM_BUF_SIZE 1024
150 * This structure is used to hold the arguments that are
151 * used when loading binaries.
153 struct linux_binprm
{
154 char buf
[BPRM_BUF_SIZE
] __attribute__((aligned
));
161 char * filename
; /* Name of binary */
162 int (*core_dump
)(int, const CPUArchState
*); /* coredump routine */
165 void do_init_thread(struct target_pt_regs
*regs
, struct image_info
*infop
);
166 abi_ulong
loader_build_argptr(int envc
, int argc
, abi_ulong sp
,
167 abi_ulong stringp
, int push_ptr
);
168 int loader_exec(int fdexec
, const char *filename
, char **argv
, char **envp
,
169 struct target_pt_regs
* regs
, struct image_info
*infop
,
170 struct linux_binprm
*);
172 int load_elf_binary(struct linux_binprm
*bprm
, struct image_info
*info
);
173 int load_flt_binary(struct linux_binprm
*bprm
, struct image_info
*info
);
175 abi_long
memcpy_to_target(abi_ulong dest
, const void *src
,
177 void target_set_brk(abi_ulong new_brk
);
178 abi_long
do_brk(abi_ulong new_brk
);
179 void syscall_init(void);
180 abi_long
do_syscall(void *cpu_env
, int num
, abi_long arg1
,
181 abi_long arg2
, abi_long arg3
, abi_long arg4
,
182 abi_long arg5
, abi_long arg6
, abi_long arg7
,
184 void gemu_log(const char *fmt
, ...) GCC_FMT_ATTR(1, 2);
185 extern THREAD CPUState
*thread_cpu
;
186 void cpu_loop(CPUArchState
*env
);
187 char *target_strerror(int err
);
188 int get_osversion(void);
189 void init_qemu_uname_release(void);
190 void fork_start(void);
191 void fork_end(int child
);
193 /* Creates the initial guest address space in the host memory space using
194 * the given host start address hint and size. The guest_start parameter
195 * specifies the start address of the guest space. guest_base will be the
196 * difference between the host start address computed by this function and
197 * guest_start. If fixed is specified, then the mapped address space must
198 * start at host_start. The real start address of the mapped memory space is
199 * returned or -1 if there was an error.
201 unsigned long init_guest_space(unsigned long host_start
,
202 unsigned long host_size
,
203 unsigned long guest_start
,
206 #include "qemu/log.h"
212 * @int number: number of system call to make
213 * ...: arguments to the system call
215 * Call a system call if guest signal not pending.
216 * This has the same API as the libc syscall() function, except that it
217 * may return -1 with errno == TARGET_ERESTARTSYS if a signal was pending.
219 * Returns: the system call result, or -1 with an error code in errno
220 * (Errnos are host errnos; we rely on TARGET_ERESTARTSYS not clashing
221 * with any of the host errno values.)
224 /* A guide to using safe_syscall() to handle interactions between guest
225 * syscalls and guest signals:
227 * Guest syscalls come in two flavours:
229 * (1) Non-interruptible syscalls
231 * These are guest syscalls that never get interrupted by signals and
232 * so never return EINTR. They can be implemented straightforwardly in
233 * QEMU: just make sure that if the implementation code has to make any
234 * blocking calls that those calls are retried if they return EINTR.
235 * It's also OK to implement these with safe_syscall, though it will be
236 * a little less efficient if a signal is delivered at the 'wrong' moment.
238 * (2) Interruptible syscalls
240 * These are guest syscalls that can be interrupted by signals and
241 * for which we need to either return EINTR or arrange for the guest
242 * syscall to be restarted. This category includes both syscalls which
243 * always restart (and in the kernel return -ERESTARTNOINTR), ones
244 * which only restart if there is no handler (kernel returns -ERESTARTNOHAND
245 * or -ERESTART_RESTARTBLOCK), and the most common kind which restart
246 * if the handler was registered with SA_RESTART (kernel returns
247 * -ERESTARTSYS). System calls which are only interruptible in some
248 * situations (like 'open') also need to be handled this way.
250 * Here it is important that the host syscall is made
251 * via this safe_syscall() function, and *not* via the host libc.
252 * If the host libc is used then the implementation will appear to work
253 * most of the time, but there will be a race condition where a
254 * signal could arrive just before we make the host syscall inside libc,
255 * and then then guest syscall will not correctly be interrupted.
256 * Instead the implementation of the guest syscall can use the safe_syscall
257 * function but otherwise just return the result or errno in the usual
258 * way; the main loop code will take care of restarting the syscall
261 * (If the implementation needs to make multiple host syscalls this is
262 * OK; any which might really block must be via safe_syscall(); for those
263 * which are only technically blocking (ie which we know in practice won't
264 * stay in the host kernel indefinitely) it's OK to use libc if necessary.
265 * You must be able to cope with backing out correctly if some safe_syscall
266 * you make in the implementation returns either -TARGET_ERESTARTSYS or
270 * How and why the safe_syscall implementation works:
272 * The basic setup is that we make the host syscall via a known
273 * section of host native assembly. If a signal occurs, our signal
274 * handler checks the interrupted host PC against the addresse of that
275 * known section. If the PC is before or at the address of the syscall
276 * instruction then we change the PC to point at a "return
277 * -TARGET_ERESTARTSYS" code path instead, and then exit the signal handler
278 * (causing the safe_syscall() call to immediately return that value).
279 * Then in the main.c loop if we see this magic return value we adjust
280 * the guest PC to wind it back to before the system call, and invoke
281 * the guest signal handler as usual.
283 * This winding-back will happen in two cases:
284 * (1) signal came in just before we took the host syscall (a race);
285 * in this case we'll take the guest signal and have another go
286 * at the syscall afterwards, and this is indistinguishable for the
287 * guest from the timing having been different such that the guest
288 * signal really did win the race
289 * (2) signal came in while the host syscall was blocking, and the
290 * host kernel decided the syscall should be restarted;
291 * in this case we want to restart the guest syscall also, and so
292 * rewinding is the right thing. (Note that "restart" semantics mean
293 * "first call the signal handler, then reattempt the syscall".)
294 * The other situation to consider is when a signal came in while the
295 * host syscall was blocking, and the host kernel decided that the syscall
296 * should not be restarted; in this case QEMU's host signal handler will
297 * be invoked with the PC pointing just after the syscall instruction,
298 * with registers indicating an EINTR return; the special code in the
299 * handler will not kick in, and we will return EINTR to the guest as
302 * Notice that we can leave the host kernel to make the decision for
303 * us about whether to do a restart of the syscall or not; we do not
304 * need to check SA_RESTART flags in QEMU or distinguish the various
305 * kinds of restartability.
307 #ifdef HAVE_SAFE_SYSCALL
308 /* The core part of this function is implemented in assembly */
309 extern long safe_syscall_base(int *pending
, long number
, ...);
311 #define safe_syscall(...) \
314 int *psp_ = &((TaskState *)thread_cpu->opaque)->signal_pending; \
315 ret_ = safe_syscall_base(psp_, __VA_ARGS__); \
316 if (is_error(ret_)) { \
325 /* Fallback for architectures which don't yet provide a safe-syscall assembly
326 * fragment; note that this is racy!
327 * This should go away when all host architectures have been updated.
329 #define safe_syscall syscall
334 int host_to_target_waitstatus(int status
);
337 void print_syscall(int num
,
338 abi_long arg1
, abi_long arg2
, abi_long arg3
,
339 abi_long arg4
, abi_long arg5
, abi_long arg6
);
340 void print_syscall_ret(int num
, abi_long arg1
);
341 extern int do_strace
;
344 void process_pending_signals(CPUArchState
*cpu_env
);
345 void signal_init(void);
346 int queue_signal(CPUArchState
*env
, int sig
, target_siginfo_t
*info
);
347 void host_to_target_siginfo(target_siginfo_t
*tinfo
, const siginfo_t
*info
);
348 void target_to_host_siginfo(siginfo_t
*info
, const target_siginfo_t
*tinfo
);
349 int target_to_host_signal(int sig
);
350 int host_to_target_signal(int sig
);
351 long do_sigreturn(CPUArchState
*env
);
352 long do_rt_sigreturn(CPUArchState
*env
);
353 abi_long
do_sigaltstack(abi_ulong uss_addr
, abi_ulong uoss_addr
, abi_ulong sp
);
354 int do_sigprocmask(int how
, const sigset_t
*set
, sigset_t
*oldset
);
358 void save_v86_state(CPUX86State
*env
);
359 void handle_vm86_trap(CPUX86State
*env
, int trapno
);
360 void handle_vm86_fault(CPUX86State
*env
);
361 int do_vm86(CPUX86State
*env
, long subfunction
, abi_ulong v86_addr
);
362 #elif defined(TARGET_SPARC64)
363 void sparc64_set_context(CPUSPARCState
*env
);
364 void sparc64_get_context(CPUSPARCState
*env
);
368 int target_mprotect(abi_ulong start
, abi_ulong len
, int prot
);
369 abi_long
target_mmap(abi_ulong start
, abi_ulong len
, int prot
,
370 int flags
, int fd
, abi_ulong offset
);
371 int target_munmap(abi_ulong start
, abi_ulong len
);
372 abi_long
target_mremap(abi_ulong old_addr
, abi_ulong old_size
,
373 abi_ulong new_size
, unsigned long flags
,
375 int target_msync(abi_ulong start
, abi_ulong len
, int flags
);
376 extern unsigned long last_brk
;
377 extern abi_ulong mmap_next_start
;
378 abi_ulong
mmap_find_vma(abi_ulong
, abi_ulong
);
379 void cpu_list_lock(void);
380 void cpu_list_unlock(void);
381 void mmap_fork_start(void);
382 void mmap_fork_end(int child
);
385 extern unsigned long guest_stack_size
;
389 #define VERIFY_READ 0
390 #define VERIFY_WRITE 1 /* implies read access */
392 static inline int access_ok(int type
, abi_ulong addr
, abi_ulong size
)
394 return page_check_range((target_ulong
)addr
, size
,
395 (type
== VERIFY_READ
) ? PAGE_READ
: (PAGE_READ
| PAGE_WRITE
)) == 0;
398 /* NOTE __get_user and __put_user use host pointers and don't check access.
399 These are usually used to access struct data members once the struct has
400 been locked - usually with lock_user_struct. */
403 - Use __builtin_choose_expr to avoid type promotion from ?:,
404 - Invalid sizes result in a compile time error stemming from
405 the fact that abort has no parameters.
406 - It's easier to use the endian-specific unaligned load/store
407 functions than host-endian unaligned load/store plus tswapN. */
409 #define __put_user_e(x, hptr, e) \
410 (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p, \
411 __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p, \
412 __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p, \
413 __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort)))) \
414 ((hptr), (x)), (void)0)
416 #define __get_user_e(x, hptr, e) \
417 ((x) = (typeof(*hptr))( \
418 __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p, \
419 __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p, \
420 __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p, \
421 __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort)))) \
424 #ifdef TARGET_WORDS_BIGENDIAN
425 # define __put_user(x, hptr) __put_user_e(x, hptr, be)
426 # define __get_user(x, hptr) __get_user_e(x, hptr, be)
428 # define __put_user(x, hptr) __put_user_e(x, hptr, le)
429 # define __get_user(x, hptr) __get_user_e(x, hptr, le)
432 /* put_user()/get_user() take a guest address and check access */
433 /* These are usually used to access an atomic data type, such as an int,
434 * that has been passed by address. These internally perform locking
435 * and unlocking on the data type.
437 #define put_user(x, gaddr, target_type) \
439 abi_ulong __gaddr = (gaddr); \
440 target_type *__hptr; \
441 abi_long __ret = 0; \
442 if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
443 __put_user((x), __hptr); \
444 unlock_user(__hptr, __gaddr, sizeof(target_type)); \
446 __ret = -TARGET_EFAULT; \
450 #define get_user(x, gaddr, target_type) \
452 abi_ulong __gaddr = (gaddr); \
453 target_type *__hptr; \
454 abi_long __ret = 0; \
455 if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
456 __get_user((x), __hptr); \
457 unlock_user(__hptr, __gaddr, 0); \
459 /* avoid warning */ \
461 __ret = -TARGET_EFAULT; \
466 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
467 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
468 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
469 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
470 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
471 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
472 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
473 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
474 #define put_user_u8(x, gaddr) put_user((x), (gaddr), uint8_t)
475 #define put_user_s8(x, gaddr) put_user((x), (gaddr), int8_t)
477 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
478 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
479 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
480 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
481 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
482 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
483 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
484 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
485 #define get_user_u8(x, gaddr) get_user((x), (gaddr), uint8_t)
486 #define get_user_s8(x, gaddr) get_user((x), (gaddr), int8_t)
488 /* copy_from_user() and copy_to_user() are usually used to copy data
489 * buffers between the target and host. These internally perform
490 * locking/unlocking of the memory.
492 abi_long
copy_from_user(void *hptr
, abi_ulong gaddr
, size_t len
);
493 abi_long
copy_to_user(abi_ulong gaddr
, void *hptr
, size_t len
);
495 /* Functions for accessing guest memory. The tget and tput functions
496 read/write single values, byteswapping as necessary. The lock_user function
497 gets a pointer to a contiguous area of guest memory, but does not perform
498 any byteswapping. lock_user may return either a pointer to the guest
499 memory, or a temporary buffer. */
501 /* Lock an area of guest memory into the host. If copy is true then the
502 host area will have the same contents as the guest. */
503 static inline void *lock_user(int type
, abi_ulong guest_addr
, long len
, int copy
)
505 if (!access_ok(type
, guest_addr
, len
))
512 memcpy(addr
, g2h(guest_addr
), len
);
514 memset(addr
, 0, len
);
518 return g2h(guest_addr
);
522 /* Unlock an area of guest memory. The first LEN bytes must be
523 flushed back to guest memory. host_ptr = NULL is explicitly
524 allowed and does nothing. */
525 static inline void unlock_user(void *host_ptr
, abi_ulong guest_addr
,
532 if (host_ptr
== g2h(guest_addr
))
535 memcpy(g2h(guest_addr
), host_ptr
, len
);
540 /* Return the length of a string in target memory or -TARGET_EFAULT if
542 abi_long
target_strlen(abi_ulong gaddr
);
544 /* Like lock_user but for null terminated strings. */
545 static inline void *lock_user_string(abi_ulong guest_addr
)
548 len
= target_strlen(guest_addr
);
551 return lock_user(VERIFY_READ
, guest_addr
, (long)(len
+ 1), 1);
554 /* Helper macros for locking/unlocking a target struct. */
555 #define lock_user_struct(type, host_ptr, guest_addr, copy) \
556 (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
557 #define unlock_user_struct(host_ptr, guest_addr, copy) \
558 unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
562 /* Include target-specific struct and function definitions;
563 * they may need access to the target-independent structures
564 * above, so include them last.
566 #include "target_cpu.h"
567 #include "target_signal.h"
568 #include "target_structs.h"