xref: /openbmc/qemu/bsd-user/qemu.h (revision 707ded20)
1 /*
2  *  qemu bsd user mode definition
3  *
4  *  This program is free software; you can redistribute it and/or modify
5  *  it under the terms of the GNU General Public License as published by
6  *  the Free Software Foundation; either version 2 of the License, or
7  *  (at your option) any later version.
8  *
9  *  This program is distributed in the hope that it will be useful,
10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  *  GNU General Public License for more details.
13  *
14  *  You should have received a copy of the GNU General Public License
15  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
16  */
17 #ifndef QEMU_H
18 #define QEMU_H
19 
20 #include "cpu.h"
21 #include "qemu/units.h"
22 #include "exec/cpu_ldst.h"
23 #include "exec/exec-all.h"
24 
25 #undef DEBUG_REMAP
26 
27 #include "exec/user/abitypes.h"
28 
29 extern char **environ;
30 
31 #include "exec/user/thunk.h"
32 #include "target_arch.h"
33 #include "syscall_defs.h"
34 #include "target_syscall.h"
35 #include "target_os_vmparam.h"
36 #include "target_os_signal.h"
37 #include "target.h"
38 #include "exec/gdbstub.h"
39 #include "qemu/clang-tsa.h"
40 
41 #include "qemu-os.h"
42 /*
43  * TODO: Remove these and rely only on qemu_real_host_page_size().
44  */
45 extern uintptr_t qemu_host_page_size;
46 extern intptr_t qemu_host_page_mask;
47 #define HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_host_page_size)
48 
49 /*
50  * This struct is used to hold certain information about the image.  Basically,
51  * it replicates in user space what would be certain task_struct fields in the
52  * kernel
53  */
54 struct image_info {
55     abi_ulong load_bias;
56     abi_ulong load_addr;
57     abi_ulong start_code;
58     abi_ulong end_code;
59     abi_ulong start_data;
60     abi_ulong end_data;
61     abi_ulong brk;
62     abi_ulong rss;
63     abi_ulong start_stack;
64     abi_ulong entry;
65     abi_ulong code_offset;
66     abi_ulong data_offset;
67     abi_ulong arg_start;
68     abi_ulong arg_end;
69     uint32_t  elf_flags;
70 };
71 
72 struct emulated_sigtable {
73     int pending; /* true if signal is pending */
74     target_siginfo_t info;
75 };
76 
77 /*
78  * NOTE: we force a big alignment so that the stack stored after is aligned too
79  */
80 typedef struct TaskState {
81     pid_t ts_tid;     /* tid (or pid) of this task */
82 
83     struct TaskState *next;
84     struct bsd_binprm *bprm;
85     struct image_info *info;
86 
87     struct emulated_sigtable sync_signal;
88     /*
89      * TODO: Since we block all signals while returning to the main CPU
90      * loop, this needn't be an array
91      */
92     struct emulated_sigtable sigtab[TARGET_NSIG];
93     /*
94      * Nonzero if process_pending_signals() needs to do something (either
95      * handle a pending signal or unblock signals).
96      * This flag is written from a signal handler so should be accessed via
97      * the qatomic_read() and qatomic_set() functions. (It is not accessed
98      * from multiple threads.)
99      */
100     int signal_pending;
101     /* True if we're leaving a sigsuspend and sigsuspend_mask is valid. */
102     bool in_sigsuspend;
103     /*
104      * This thread's signal mask, as requested by the guest program.
105      * The actual signal mask of this thread may differ:
106      *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
107      *  + sometimes we block all signals to avoid races
108      */
109     sigset_t signal_mask;
110     /*
111      * The signal mask imposed by a guest sigsuspend syscall, if we are
112      * currently in the middle of such a syscall
113      */
114     sigset_t sigsuspend_mask;
115 
116     /* This thread's sigaltstack, if it has one */
117     struct target_sigaltstack sigaltstack_used;
118 } __attribute__((aligned(16))) TaskState;
119 
120 void stop_all_tasks(void);
121 extern const char *interp_prefix;
122 extern const char *qemu_uname_release;
123 
124 /*
125  * TARGET_ARG_MAX defines the number of bytes allocated for arguments
126  * and envelope for the new program. 256k should suffice for a reasonable
127  * maximum env+arg in 32-bit environments, bump it up to 512k for !ILP32
128  * platforms.
129  */
130 #if TARGET_ABI_BITS > 32
131 #define TARGET_ARG_MAX (512 * KiB)
132 #else
133 #define TARGET_ARG_MAX (256 * KiB)
134 #endif
135 #define MAX_ARG_PAGES (TARGET_ARG_MAX / TARGET_PAGE_SIZE)
136 
137 /*
138  * This structure is used to hold the arguments that are
139  * used when loading binaries.
140  */
141 struct bsd_binprm {
142         char buf[128];
143         void *page[MAX_ARG_PAGES];
144         abi_ulong p;
145         abi_ulong stringp;
146         int fd;
147         int e_uid, e_gid;
148         int argc, envc;
149         char **argv;
150         char **envp;
151         char *filename;         /* (Given) Name of binary */
152         char *fullpath;         /* Full path of binary */
153         int (*core_dump)(int, CPUArchState *);
154 };
155 
156 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
157 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
158                               abi_ulong stringp);
159 int loader_exec(const char *filename, char **argv, char **envp,
160                 struct target_pt_regs *regs, struct image_info *infop,
161                 struct bsd_binprm *bprm);
162 
163 int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
164                     struct image_info *info);
165 int load_flt_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
166                     struct image_info *info);
167 int is_target_elf_binary(int fd);
168 
169 abi_long memcpy_to_target(abi_ulong dest, const void *src,
170                           unsigned long len);
171 void target_set_brk(abi_ulong new_brk);
172 abi_long do_brk(abi_ulong new_brk);
173 void syscall_init(void);
174 abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1,
175                             abi_long arg2, abi_long arg3, abi_long arg4,
176                             abi_long arg5, abi_long arg6, abi_long arg7,
177                             abi_long arg8);
178 abi_long do_netbsd_syscall(void *cpu_env, int num, abi_long arg1,
179                            abi_long arg2, abi_long arg3, abi_long arg4,
180                            abi_long arg5, abi_long arg6);
181 abi_long do_openbsd_syscall(void *cpu_env, int num, abi_long arg1,
182                             abi_long arg2, abi_long arg3, abi_long arg4,
183                             abi_long arg5, abi_long arg6);
184 void gemu_log(const char *fmt, ...) G_GNUC_PRINTF(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 fork_start(void);
190 void fork_end(int child);
191 
192 #include "qemu/log.h"
193 
194 /* strace.c */
195 struct syscallname {
196     int nr;
197     const char *name;
198     const char *format;
199     void (*call)(const struct syscallname *,
200                  abi_long, abi_long, abi_long,
201                  abi_long, abi_long, abi_long);
202     void (*result)(const struct syscallname *, abi_long);
203 };
204 
205 void
206 print_freebsd_syscall(int num,
207                       abi_long arg1, abi_long arg2, abi_long arg3,
208                       abi_long arg4, abi_long arg5, abi_long arg6);
209 void print_freebsd_syscall_ret(int num, abi_long ret);
210 void
211 print_netbsd_syscall(int num,
212                      abi_long arg1, abi_long arg2, abi_long arg3,
213                      abi_long arg4, abi_long arg5, abi_long arg6);
214 void print_netbsd_syscall_ret(int num, abi_long ret);
215 void
216 print_openbsd_syscall(int num,
217                       abi_long arg1, abi_long arg2, abi_long arg3,
218                       abi_long arg4, abi_long arg5, abi_long arg6);
219 void print_openbsd_syscall_ret(int num, abi_long ret);
220 /**
221  * print_taken_signal:
222  * @target_signum: target signal being taken
223  * @tinfo: target_siginfo_t which will be passed to the guest for the signal
224  *
225  * Print strace output indicating that this signal is being taken by the guest,
226  * in a format similar to:
227  * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
228  */
229 void print_taken_signal(int target_signum, const target_siginfo_t *tinfo);
230 extern int do_strace;
231 
232 /* mmap.c */
233 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
234 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
235                      int flags, int fd, off_t offset);
236 int target_munmap(abi_ulong start, abi_ulong len);
237 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
238                        abi_ulong new_size, unsigned long flags,
239                        abi_ulong new_addr);
240 int target_msync(abi_ulong start, abi_ulong len, int flags);
241 extern abi_ulong mmap_next_start;
242 abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size);
243 void mmap_reserve(abi_ulong start, abi_ulong size);
244 void TSA_NO_TSA mmap_fork_start(void);
245 void TSA_NO_TSA mmap_fork_end(int child);
246 
247 /* main.c */
248 extern char qemu_proc_pathname[];
249 extern unsigned long target_maxtsiz;
250 extern unsigned long target_dfldsiz;
251 extern unsigned long target_maxdsiz;
252 extern unsigned long target_dflssiz;
253 extern unsigned long target_maxssiz;
254 extern unsigned long target_sgrowsiz;
255 
256 /* os-syscall.c */
257 abi_long get_errno(abi_long ret);
258 bool is_error(abi_long ret);
259 int host_to_target_errno(int err);
260 
261 /* os-proc.c */
262 abi_long freebsd_exec_common(abi_ulong path_or_fd, abi_ulong guest_argp,
263         abi_ulong guest_envp, int do_fexec);
264 abi_long do_freebsd_procctl(void *cpu_env, int idtype, abi_ulong arg2,
265         abi_ulong arg3, abi_ulong arg4, abi_ulong arg5, abi_ulong arg6);
266 
267 /* os-sys.c */
268 abi_long do_freebsd_sysctl(CPUArchState *env, abi_ulong namep, int32_t namelen,
269         abi_ulong oldp, abi_ulong oldlenp, abi_ulong newp, abi_ulong newlen);
270 abi_long do_freebsd_sysctlbyname(CPUArchState *env, abi_ulong namep,
271         int32_t namelen, abi_ulong oldp, abi_ulong oldlenp, abi_ulong newp,
272         abi_ulong newlen);
273 abi_long do_freebsd_sysarch(void *cpu_env, abi_long arg1, abi_long arg2);
274 
275 /* user access */
276 
277 #define VERIFY_READ  PAGE_READ
278 #define VERIFY_WRITE (PAGE_READ | PAGE_WRITE)
279 
280 static inline bool access_ok(int type, abi_ulong addr, abi_ulong size)
281 {
282     return page_check_range((target_ulong)addr, size, type);
283 }
284 
285 /*
286  * NOTE __get_user and __put_user use host pointers and don't check access.
287  *
288  * These are usually used to access struct data members once the struct has been
289  * locked - usually with lock_user_struct().
290  */
291 
292 /*
293  * Tricky points:
294  * - Use __builtin_choose_expr to avoid type promotion from ?:,
295  * - Invalid sizes result in a compile time error stemming from
296  *   the fact that abort has no parameters.
297  * - It's easier to use the endian-specific unaligned load/store
298  *   functions than host-endian unaligned load/store plus tswapN.
299  * - The pragmas are necessary only to silence a clang false-positive
300  *   warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
301  * - gcc has bugs in its _Pragma() support in some versions, eg
302  *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
303  *   include the warning-suppression pragmas for clang
304  */
305 #if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
306 #define PRAGMA_DISABLE_PACKED_WARNING                                   \
307     _Pragma("GCC diagnostic push");                                     \
308     _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")
309 
310 #define PRAGMA_REENABLE_PACKED_WARNING          \
311     _Pragma("GCC diagnostic pop")
312 
313 #else
314 #define PRAGMA_DISABLE_PACKED_WARNING
315 #define PRAGMA_REENABLE_PACKED_WARNING
316 #endif
317 
318 #define __put_user_e(x, hptr, e)                                            \
319     do {                                                                    \
320         PRAGMA_DISABLE_PACKED_WARNING;                                      \
321         (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                 \
322         __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,            \
323         __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,            \
324         __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))  \
325             ((hptr), (x)), (void)0);                                        \
326         PRAGMA_REENABLE_PACKED_WARNING;                                     \
327     } while (0)
328 
329 #define __get_user_e(x, hptr, e)                                            \
330     do {                                                                    \
331         PRAGMA_DISABLE_PACKED_WARNING;                                      \
332         ((x) = (typeof(*hptr))(                                             \
333         __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                 \
334         __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,           \
335         __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,            \
336         __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))  \
337             (hptr)), (void)0);                                              \
338         PRAGMA_REENABLE_PACKED_WARNING;                                     \
339     } while (0)
340 
341 
342 #if TARGET_BIG_ENDIAN
343 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
344 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
345 #else
346 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
347 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
348 #endif
349 
350 /*
351  * put_user()/get_user() take a guest address and check access
352  *
353  * These are usually used to access an atomic data type, such as an int, that
354  * has been passed by address.  These internally perform locking and unlocking
355  * on the data type.
356  */
357 #define put_user(x, gaddr, target_type)                                 \
358 ({                                                                      \
359     abi_ulong __gaddr = (gaddr);                                        \
360     target_type *__hptr;                                                \
361     abi_long __ret = 0;                                                 \
362     __hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0);  \
363     if (__hptr) {                                                       \
364         __put_user((x), __hptr);                                        \
365         unlock_user(__hptr, __gaddr, sizeof(target_type));              \
366     } else                                                              \
367         __ret = -TARGET_EFAULT;                                         \
368     __ret;                                                              \
369 })
370 
371 #define get_user(x, gaddr, target_type)                                 \
372 ({                                                                      \
373     abi_ulong __gaddr = (gaddr);                                        \
374     target_type *__hptr;                                                \
375     abi_long __ret = 0;                                                 \
376     __hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1);   \
377     if (__hptr) {                                                       \
378         __get_user((x), __hptr);                                        \
379         unlock_user(__hptr, __gaddr, 0);                                \
380     } else {                                                            \
381         (x) = 0;                                                        \
382         __ret = -TARGET_EFAULT;                                         \
383     }                                                                   \
384     __ret;                                                              \
385 })
386 
387 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
388 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
389 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
390 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
391 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
392 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
393 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
394 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
395 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
396 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
397 
398 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
399 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
400 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
401 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
402 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
403 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
404 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
405 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
406 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
407 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
408 
409 /*
410  * copy_from_user() and copy_to_user() are usually used to copy data
411  * buffers between the target and host.  These internally perform
412  * locking/unlocking of the memory.
413  */
414 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
415 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
416 
417 /*
418  * Functions for accessing guest memory.  The tget and tput functions
419  * read/write single values, byteswapping as necessary.  The lock_user function
420  * gets a pointer to a contiguous area of guest memory, but does not perform
421  * any byteswapping.  lock_user may return either a pointer to the guest
422  * memory, or a temporary buffer.
423  */
424 
425 /*
426  * Lock an area of guest memory into the host.  If copy is true then the
427  * host area will have the same contents as the guest.
428  */
429 static inline void *lock_user(int type, abi_ulong guest_addr, long len,
430                               int copy)
431 {
432     if (!access_ok(type, guest_addr, len)) {
433         return NULL;
434     }
435 #ifdef DEBUG_REMAP
436     {
437         void *addr;
438         addr = g_malloc(len);
439         if (copy) {
440             memcpy(addr, g2h_untagged(guest_addr), len);
441         } else {
442             memset(addr, 0, len);
443         }
444         return addr;
445     }
446 #else
447     return g2h_untagged(guest_addr);
448 #endif
449 }
450 
451 /*
452  * Unlock an area of guest memory.  The first LEN bytes must be flushed back to
453  * guest memory. host_ptr = NULL is explicitly allowed and does nothing.
454  */
455 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
456                                long len)
457 {
458 
459 #ifdef DEBUG_REMAP
460     if (!host_ptr) {
461         return;
462     }
463     if (host_ptr == g2h_untagged(guest_addr)) {
464         return;
465     }
466     if (len > 0) {
467         memcpy(g2h_untagged(guest_addr), host_ptr, len);
468     }
469     g_free(host_ptr);
470 #endif
471 }
472 
473 /*
474  * Return the length of a string in target memory or -TARGET_EFAULT if access
475  * error.
476  */
477 abi_long target_strlen(abi_ulong gaddr);
478 
479 /* Like lock_user but for null terminated strings.  */
480 static inline void *lock_user_string(abi_ulong guest_addr)
481 {
482     abi_long len;
483     len = target_strlen(guest_addr);
484     if (len < 0) {
485         return NULL;
486     }
487     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
488 }
489 
490 /* Helper macros for locking/unlocking a target struct.  */
491 #define lock_user_struct(type, host_ptr, guest_addr, copy)      \
492     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
493 #define unlock_user_struct(host_ptr, guest_addr, copy)          \
494     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
495 
496 static inline uint64_t target_arg64(uint32_t word0, uint32_t word1)
497 {
498 #if TARGET_ABI_BITS == 32
499 #if TARGET_BIG_ENDIAN
500     return ((uint64_t)word0 << 32) | word1;
501 #else
502     return ((uint64_t)word1 << 32) | word0;
503 #endif
504 #else /* TARGET_ABI_BITS != 32 */
505     return word0;
506 #endif /* TARGET_ABI_BITS != 32 */
507 }
508 
509 #include <pthread.h>
510 
511 #include "user/safe-syscall.h"
512 
513 #endif /* QEMU_H */
514