xref: /openbmc/qemu/bsd-user/qemu.h (revision ef932e21bd83c1beab94b10989bf6e8424a886c2)
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 #include "user/abitypes.h"
26 
27 extern char **environ;
28 
29 #include "user/thunk.h"
30 #include "target_arch.h"
31 #include "syscall_defs.h"
32 #include "target_syscall.h"
33 #include "target_os_vmparam.h"
34 #include "target_os_signal.h"
35 #include "target.h"
36 #include "exec/gdbstub.h"
37 #include "exec/page-protection.h"
38 #include "qemu/clang-tsa.h"
39 
40 #include "qemu-os.h"
41 /*
42  * TODO: Remove these and rely only on qemu_real_host_page_size().
43  */
44 extern uintptr_t qemu_host_page_size;
45 extern intptr_t qemu_host_page_mask;
46 #define HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_host_page_size)
47 
48 /*
49  * This struct is used to hold certain information about the image.  Basically,
50  * it replicates in user space what would be certain task_struct fields in the
51  * kernel
52  */
53 struct image_info {
54     abi_ulong load_bias;
55     abi_ulong load_addr;
56     abi_ulong start_code;
57     abi_ulong end_code;
58     abi_ulong start_data;
59     abi_ulong end_data;
60     abi_ulong brk;
61     abi_ulong rss;
62     abi_ulong start_stack;
63     abi_ulong entry;
64     abi_ulong code_offset;
65     abi_ulong data_offset;
66     abi_ulong arg_start;
67     abi_ulong arg_end;
68     uint32_t  elf_flags;
69 };
70 
71 struct emulated_sigtable {
72     int pending; /* true if signal is pending */
73     target_siginfo_t info;
74 };
75 
76 /*
77  * NOTE: we force a big alignment so that the stack stored after is aligned too
78  */
79 struct TaskState {
80     pid_t ts_tid;     /* tid (or pid) of this task */
81 
82     struct TaskState *next;
83     struct bsd_binprm *bprm;
84     struct image_info *info;
85 
86     struct emulated_sigtable sync_signal;
87     /*
88      * TODO: Since we block all signals while returning to the main CPU
89      * loop, this needn't be an array
90      */
91     struct emulated_sigtable sigtab[TARGET_NSIG];
92     /*
93      * Nonzero if process_pending_signals() needs to do something (either
94      * handle a pending signal or unblock signals).
95      * This flag is written from a signal handler so should be accessed via
96      * the qatomic_read() and qatomic_set() functions. (It is not accessed
97      * from multiple threads.)
98      */
99     int signal_pending;
100     /* True if we're leaving a sigsuspend and sigsuspend_mask is valid. */
101     bool in_sigsuspend;
102     /*
103      * This thread's signal mask, as requested by the guest program.
104      * The actual signal mask of this thread may differ:
105      *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
106      *  + sometimes we block all signals to avoid races
107      */
108     sigset_t signal_mask;
109     /*
110      * The signal mask imposed by a guest sigsuspend syscall, if we are
111      * currently in the middle of such a syscall
112      */
113     sigset_t sigsuspend_mask;
114 
115     /* This thread's sigaltstack, if it has one */
116     struct target_sigaltstack sigaltstack_used;
117 } __attribute__((aligned(16)));
118 
119 static inline TaskState *get_task_state(CPUState *cs)
120 {
121     return cs->opaque;
122 }
123 
124 void stop_all_tasks(void);
125 extern const char *interp_prefix;
126 extern const char *qemu_uname_release;
127 
128 /*
129  * TARGET_ARG_MAX defines the number of bytes allocated for arguments
130  * and envelope for the new program. 256k should suffice for a reasonable
131  * maximum env+arg in 32-bit environments, bump it up to 512k for !ILP32
132  * platforms.
133  */
134 #if TARGET_ABI_BITS > 32
135 #define TARGET_ARG_MAX (512 * KiB)
136 #else
137 #define TARGET_ARG_MAX (256 * KiB)
138 #endif
139 #define MAX_ARG_PAGES (TARGET_ARG_MAX / TARGET_PAGE_SIZE)
140 
141 /*
142  * This structure is used to hold the arguments that are
143  * used when loading binaries.
144  */
145 struct bsd_binprm {
146         char buf[128];
147         void *page[MAX_ARG_PAGES];
148         abi_ulong p;
149         abi_ulong stringp;
150         int fd;
151         int e_uid, e_gid;
152         int argc, envc;
153         char **argv;
154         char **envp;
155         char *filename;         /* (Given) Name of binary */
156         char *fullpath;         /* Full path of binary */
157         int (*core_dump)(int, CPUArchState *);
158 };
159 
160 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
161 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
162                               abi_ulong stringp);
163 int loader_exec(const char *filename, char **argv, char **envp,
164                 struct target_pt_regs *regs, struct image_info *infop,
165                 struct bsd_binprm *bprm);
166 
167 int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
168                     struct image_info *info);
169 int load_flt_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
170                     struct image_info *info);
171 int is_target_elf_binary(int fd);
172 
173 abi_long memcpy_to_target(abi_ulong dest, const void *src,
174                           unsigned long len);
175 void target_set_brk(abi_ulong new_brk);
176 abi_long do_brk(abi_ulong new_brk);
177 void syscall_init(void);
178 abi_long do_freebsd_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, abi_long arg7,
181                             abi_long arg8);
182 abi_long do_netbsd_syscall(void *cpu_env, int num, abi_long arg1,
183                            abi_long arg2, abi_long arg3, abi_long arg4,
184                            abi_long arg5, abi_long arg6);
185 abi_long do_openbsd_syscall(void *cpu_env, int num, abi_long arg1,
186                             abi_long arg2, abi_long arg3, abi_long arg4,
187                             abi_long arg5, abi_long arg6);
188 void gemu_log(const char *fmt, ...) G_GNUC_PRINTF(1, 2);
189 extern __thread CPUState *thread_cpu;
190 void cpu_loop(CPUArchState *env);
191 char *target_strerror(int err);
192 int get_osversion(void);
193 void fork_start(void);
194 void fork_end(pid_t pid);
195 
196 #include "qemu/log.h"
197 
198 /* strace.c */
199 struct syscallname {
200     int nr;
201     const char *name;
202     const char *format;
203     void (*call)(const struct syscallname *,
204                  abi_long, abi_long, abi_long,
205                  abi_long, abi_long, abi_long);
206     void (*result)(const struct syscallname *, abi_long);
207 };
208 
209 void
210 print_freebsd_syscall(int num,
211                       abi_long arg1, abi_long arg2, abi_long arg3,
212                       abi_long arg4, abi_long arg5, abi_long arg6);
213 void print_freebsd_syscall_ret(int num, abi_long ret);
214 void
215 print_netbsd_syscall(int num,
216                      abi_long arg1, abi_long arg2, abi_long arg3,
217                      abi_long arg4, abi_long arg5, abi_long arg6);
218 void print_netbsd_syscall_ret(int num, abi_long ret);
219 void
220 print_openbsd_syscall(int num,
221                       abi_long arg1, abi_long arg2, abi_long arg3,
222                       abi_long arg4, abi_long arg5, abi_long arg6);
223 void print_openbsd_syscall_ret(int num, abi_long ret);
224 /**
225  * print_taken_signal:
226  * @target_signum: target signal being taken
227  * @tinfo: target_siginfo_t which will be passed to the guest for the signal
228  *
229  * Print strace output indicating that this signal is being taken by the guest,
230  * in a format similar to:
231  * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
232  */
233 void print_taken_signal(int target_signum, const target_siginfo_t *tinfo);
234 extern int do_strace;
235 
236 /* mmap.c */
237 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
238 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
239                      int flags, int fd, off_t offset);
240 int target_munmap(abi_ulong start, abi_ulong len);
241 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
242                        abi_ulong new_size, unsigned long flags,
243                        abi_ulong new_addr);
244 int target_msync(abi_ulong start, abi_ulong len, int flags);
245 extern abi_ulong mmap_next_start;
246 abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size);
247 void mmap_reserve(abi_ulong start, abi_ulong size);
248 void TSA_NO_TSA mmap_fork_start(void);
249 void TSA_NO_TSA mmap_fork_end(int child);
250 
251 /* main.c */
252 extern char qemu_proc_pathname[];
253 extern unsigned long target_maxtsiz;
254 extern unsigned long target_dfldsiz;
255 extern unsigned long target_maxdsiz;
256 extern unsigned long target_dflssiz;
257 extern unsigned long target_maxssiz;
258 extern unsigned long target_sgrowsiz;
259 
260 /* os-syscall.c */
261 abi_long get_errno(abi_long ret);
262 bool is_error(abi_long ret);
263 int host_to_target_errno(int err);
264 
265 /* os-proc.c */
266 abi_long freebsd_exec_common(abi_ulong path_or_fd, abi_ulong guest_argp,
267         abi_ulong guest_envp, int do_fexec);
268 abi_long do_freebsd_procctl(void *cpu_env, int idtype, abi_ulong arg2,
269         abi_ulong arg3, abi_ulong arg4, abi_ulong arg5, abi_ulong arg6);
270 
271 /* os-sys.c */
272 abi_long do_freebsd_sysctl(CPUArchState *env, abi_ulong namep, int32_t namelen,
273         abi_ulong oldp, abi_ulong oldlenp, abi_ulong newp, abi_ulong newlen);
274 abi_long do_freebsd_sysctlbyname(CPUArchState *env, abi_ulong namep,
275         int32_t namelen, abi_ulong oldp, abi_ulong oldlenp, abi_ulong newp,
276         abi_ulong newlen);
277 abi_long do_freebsd_sysarch(void *cpu_env, abi_long arg1, abi_long arg2);
278 
279 /* user access */
280 
281 #define VERIFY_READ  PAGE_READ
282 #define VERIFY_WRITE (PAGE_READ | PAGE_WRITE)
283 
284 static inline bool access_ok(int type, abi_ulong addr, abi_ulong size)
285 {
286     return page_check_range((target_ulong)addr, size, type);
287 }
288 
289 /*
290  * NOTE __get_user and __put_user use host pointers and don't check access.
291  *
292  * These are usually used to access struct data members once the struct has been
293  * locked - usually with lock_user_struct().
294  */
295 
296 /*
297  * Tricky points:
298  * - Use __builtin_choose_expr to avoid type promotion from ?:,
299  * - Invalid sizes result in a compile time error stemming from
300  *   the fact that abort has no parameters.
301  * - It's easier to use the endian-specific unaligned load/store
302  *   functions than host-endian unaligned load/store plus tswapN.
303  * - The pragmas are necessary only to silence a clang false-positive
304  *   warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
305  * - gcc has bugs in its _Pragma() support in some versions, eg
306  *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
307  *   include the warning-suppression pragmas for clang
308  */
309 #if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
310 #define PRAGMA_DISABLE_PACKED_WARNING                                   \
311     _Pragma("GCC diagnostic push");                                     \
312     _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")
313 
314 #define PRAGMA_REENABLE_PACKED_WARNING          \
315     _Pragma("GCC diagnostic pop")
316 
317 #else
318 #define PRAGMA_DISABLE_PACKED_WARNING
319 #define PRAGMA_REENABLE_PACKED_WARNING
320 #endif
321 
322 #define __put_user_e(x, hptr, e)                                            \
323     do {                                                                    \
324         PRAGMA_DISABLE_PACKED_WARNING;                                      \
325         (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                 \
326         __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,            \
327         __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,            \
328         __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))  \
329             ((hptr), (x)), (void)0);                                        \
330         PRAGMA_REENABLE_PACKED_WARNING;                                     \
331     } while (0)
332 
333 #define __get_user_e(x, hptr, e)                                            \
334     do {                                                                    \
335         PRAGMA_DISABLE_PACKED_WARNING;                                      \
336         ((x) = (typeof(*hptr))(                                             \
337         __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                 \
338         __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,           \
339         __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,            \
340         __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))  \
341             (hptr)), (void)0);                                              \
342         PRAGMA_REENABLE_PACKED_WARNING;                                     \
343     } while (0)
344 
345 
346 #if TARGET_BIG_ENDIAN
347 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
348 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
349 #else
350 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
351 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
352 #endif
353 
354 /*
355  * put_user()/get_user() take a guest address and check access
356  *
357  * These are usually used to access an atomic data type, such as an int, that
358  * has been passed by address.  These internally perform locking and unlocking
359  * on the data type.
360  */
361 #define put_user(x, gaddr, target_type)                                 \
362 ({                                                                      \
363     abi_ulong __gaddr = (gaddr);                                        \
364     target_type *__hptr;                                                \
365     abi_long __ret = 0;                                                 \
366     __hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0);  \
367     if (__hptr) {                                                       \
368         __put_user((x), __hptr);                                        \
369         unlock_user(__hptr, __gaddr, sizeof(target_type));              \
370     } else                                                              \
371         __ret = -TARGET_EFAULT;                                         \
372     __ret;                                                              \
373 })
374 
375 #define get_user(x, gaddr, target_type)                                 \
376 ({                                                                      \
377     abi_ulong __gaddr = (gaddr);                                        \
378     target_type *__hptr;                                                \
379     abi_long __ret = 0;                                                 \
380     __hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1);   \
381     if (__hptr) {                                                       \
382         __get_user((x), __hptr);                                        \
383         unlock_user(__hptr, __gaddr, 0);                                \
384     } else {                                                            \
385         (x) = 0;                                                        \
386         __ret = -TARGET_EFAULT;                                         \
387     }                                                                   \
388     __ret;                                                              \
389 })
390 
391 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
392 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
393 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
394 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
395 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
396 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
397 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
398 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
399 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
400 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
401 
402 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
403 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
404 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
405 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
406 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
407 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
408 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
409 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
410 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
411 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
412 
413 /*
414  * copy_from_user() and copy_to_user() are usually used to copy data
415  * buffers between the target and host.  These internally perform
416  * locking/unlocking of the memory.
417  */
418 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
419 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
420 
421 /*
422  * Functions for accessing guest memory.  The tget and tput functions
423  * read/write single values, byteswapping as necessary.  The lock_user function
424  * gets a pointer to a contiguous area of guest memory, but does not perform
425  * any byteswapping.  lock_user may return either a pointer to the guest
426  * memory, or a temporary buffer.
427  */
428 
429 /*
430  * Lock an area of guest memory into the host.  If copy is true then the
431  * host area will have the same contents as the guest.
432  */
433 static inline void *lock_user(int type, abi_ulong guest_addr, long len,
434                               int copy)
435 {
436     if (!access_ok(type, guest_addr, len)) {
437         return NULL;
438     }
439 #ifdef CONFIG_DEBUG_REMAP
440     {
441         void *addr;
442         addr = g_malloc(len);
443         if (copy) {
444             memcpy(addr, g2h_untagged(guest_addr), len);
445         } else {
446             memset(addr, 0, len);
447         }
448         return addr;
449     }
450 #else
451     return g2h_untagged(guest_addr);
452 #endif
453 }
454 
455 /*
456  * Unlock an area of guest memory.  The first LEN bytes must be flushed back to
457  * guest memory. host_ptr = NULL is explicitly allowed and does nothing.
458  */
459 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
460                                long len)
461 {
462 
463 #ifdef CONFIG_DEBUG_REMAP
464     if (!host_ptr) {
465         return;
466     }
467     if (host_ptr == g2h_untagged(guest_addr)) {
468         return;
469     }
470     if (len > 0) {
471         memcpy(g2h_untagged(guest_addr), host_ptr, len);
472     }
473     g_free(host_ptr);
474 #endif
475 }
476 
477 /*
478  * Return the length of a string in target memory or -TARGET_EFAULT if access
479  * error.
480  */
481 abi_long target_strlen(abi_ulong gaddr);
482 
483 /* Like lock_user but for null terminated strings.  */
484 static inline void *lock_user_string(abi_ulong guest_addr)
485 {
486     abi_long len;
487     len = target_strlen(guest_addr);
488     if (len < 0) {
489         return NULL;
490     }
491     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
492 }
493 
494 /* Helper macros for locking/unlocking a target struct.  */
495 #define lock_user_struct(type, host_ptr, guest_addr, copy)      \
496     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
497 #define unlock_user_struct(host_ptr, guest_addr, copy)          \
498     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
499 
500 static inline uint64_t target_arg64(uint32_t word0, uint32_t word1)
501 {
502 #if TARGET_ABI_BITS == 32
503 #if TARGET_BIG_ENDIAN
504     return ((uint64_t)word0 << 32) | word1;
505 #else
506     return ((uint64_t)word1 << 32) | word0;
507 #endif
508 #else /* TARGET_ABI_BITS != 32 */
509     return word0;
510 #endif /* TARGET_ABI_BITS != 32 */
511 }
512 
513 #include <pthread.h>
514 
515 #include "user/safe-syscall.h"
516 
517 #endif /* QEMU_H */
518