xref: /openbmc/qemu/bsd-user/qemu.h (revision 542b10bd)
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  * This struct is used to hold certain information about the image.  Basically,
44  * it replicates in user space what would be certain task_struct fields in the
45  * kernel
46  */
47 struct image_info {
48     abi_ulong load_bias;
49     abi_ulong load_addr;
50     abi_ulong start_code;
51     abi_ulong end_code;
52     abi_ulong start_data;
53     abi_ulong end_data;
54     abi_ulong brk;
55     abi_ulong rss;
56     abi_ulong start_stack;
57     abi_ulong entry;
58     abi_ulong code_offset;
59     abi_ulong data_offset;
60     abi_ulong arg_start;
61     abi_ulong arg_end;
62     uint32_t  elf_flags;
63 };
64 
65 struct emulated_sigtable {
66     int pending; /* true if signal is pending */
67     target_siginfo_t info;
68 };
69 
70 /*
71  * NOTE: we force a big alignment so that the stack stored after is aligned too
72  */
73 typedef struct TaskState {
74     pid_t ts_tid;     /* tid (or pid) of this task */
75 
76     struct TaskState *next;
77     struct bsd_binprm *bprm;
78     struct image_info *info;
79 
80     struct emulated_sigtable sync_signal;
81     /*
82      * TODO: Since we block all signals while returning to the main CPU
83      * loop, this needn't be an array
84      */
85     struct emulated_sigtable sigtab[TARGET_NSIG];
86     /*
87      * Nonzero if process_pending_signals() needs to do something (either
88      * handle a pending signal or unblock signals).
89      * This flag is written from a signal handler so should be accessed via
90      * the qatomic_read() and qatomic_set() functions. (It is not accessed
91      * from multiple threads.)
92      */
93     int signal_pending;
94     /* True if we're leaving a sigsuspend and sigsuspend_mask is valid. */
95     bool in_sigsuspend;
96     /*
97      * This thread's signal mask, as requested by the guest program.
98      * The actual signal mask of this thread may differ:
99      *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
100      *  + sometimes we block all signals to avoid races
101      */
102     sigset_t signal_mask;
103     /*
104      * The signal mask imposed by a guest sigsuspend syscall, if we are
105      * currently in the middle of such a syscall
106      */
107     sigset_t sigsuspend_mask;
108 
109     /* This thread's sigaltstack, if it has one */
110     struct target_sigaltstack sigaltstack_used;
111 } __attribute__((aligned(16))) TaskState;
112 
113 void stop_all_tasks(void);
114 extern const char *interp_prefix;
115 extern const char *qemu_uname_release;
116 
117 /*
118  * TARGET_ARG_MAX defines the number of bytes allocated for arguments
119  * and envelope for the new program. 256k should suffice for a reasonable
120  * maximum env+arg in 32-bit environments, bump it up to 512k for !ILP32
121  * platforms.
122  */
123 #if TARGET_ABI_BITS > 32
124 #define TARGET_ARG_MAX (512 * KiB)
125 #else
126 #define TARGET_ARG_MAX (256 * KiB)
127 #endif
128 #define MAX_ARG_PAGES (TARGET_ARG_MAX / TARGET_PAGE_SIZE)
129 
130 /*
131  * This structure is used to hold the arguments that are
132  * used when loading binaries.
133  */
134 struct bsd_binprm {
135         char buf[128];
136         void *page[MAX_ARG_PAGES];
137         abi_ulong p;
138         abi_ulong stringp;
139         int fd;
140         int e_uid, e_gid;
141         int argc, envc;
142         char **argv;
143         char **envp;
144         char *filename;         /* (Given) Name of binary */
145         char *fullpath;         /* Full path of binary */
146         int (*core_dump)(int, CPUArchState *);
147 };
148 
149 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
150 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
151                               abi_ulong stringp);
152 int loader_exec(const char *filename, char **argv, char **envp,
153                 struct target_pt_regs *regs, struct image_info *infop,
154                 struct bsd_binprm *bprm);
155 
156 int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
157                     struct image_info *info);
158 int load_flt_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
159                     struct image_info *info);
160 int is_target_elf_binary(int fd);
161 
162 abi_long memcpy_to_target(abi_ulong dest, const void *src,
163                           unsigned long len);
164 void target_set_brk(abi_ulong new_brk);
165 abi_long do_brk(abi_ulong new_brk);
166 void syscall_init(void);
167 abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1,
168                             abi_long arg2, abi_long arg3, abi_long arg4,
169                             abi_long arg5, abi_long arg6, abi_long arg7,
170                             abi_long arg8);
171 abi_long do_netbsd_syscall(void *cpu_env, int num, abi_long arg1,
172                            abi_long arg2, abi_long arg3, abi_long arg4,
173                            abi_long arg5, abi_long arg6);
174 abi_long do_openbsd_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);
177 void gemu_log(const char *fmt, ...) G_GNUC_PRINTF(1, 2);
178 extern __thread CPUState *thread_cpu;
179 void cpu_loop(CPUArchState *env);
180 char *target_strerror(int err);
181 int get_osversion(void);
182 void fork_start(void);
183 void fork_end(int child);
184 
185 #include "qemu/log.h"
186 
187 /* strace.c */
188 struct syscallname {
189     int nr;
190     const char *name;
191     const char *format;
192     void (*call)(const struct syscallname *,
193                  abi_long, abi_long, abi_long,
194                  abi_long, abi_long, abi_long);
195     void (*result)(const struct syscallname *, abi_long);
196 };
197 
198 void
199 print_freebsd_syscall(int num,
200                       abi_long arg1, abi_long arg2, abi_long arg3,
201                       abi_long arg4, abi_long arg5, abi_long arg6);
202 void print_freebsd_syscall_ret(int num, abi_long ret);
203 void
204 print_netbsd_syscall(int num,
205                      abi_long arg1, abi_long arg2, abi_long arg3,
206                      abi_long arg4, abi_long arg5, abi_long arg6);
207 void print_netbsd_syscall_ret(int num, abi_long ret);
208 void
209 print_openbsd_syscall(int num,
210                       abi_long arg1, abi_long arg2, abi_long arg3,
211                       abi_long arg4, abi_long arg5, abi_long arg6);
212 void print_openbsd_syscall_ret(int num, abi_long ret);
213 /**
214  * print_taken_signal:
215  * @target_signum: target signal being taken
216  * @tinfo: target_siginfo_t which will be passed to the guest for the signal
217  *
218  * Print strace output indicating that this signal is being taken by the guest,
219  * in a format similar to:
220  * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
221  */
222 void print_taken_signal(int target_signum, const target_siginfo_t *tinfo);
223 extern int do_strace;
224 
225 /* mmap.c */
226 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
227 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
228                      int flags, int fd, off_t offset);
229 int target_munmap(abi_ulong start, abi_ulong len);
230 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
231                        abi_ulong new_size, unsigned long flags,
232                        abi_ulong new_addr);
233 int target_msync(abi_ulong start, abi_ulong len, int flags);
234 extern abi_ulong mmap_next_start;
235 abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size);
236 void mmap_reserve(abi_ulong start, abi_ulong size);
237 void TSA_NO_TSA mmap_fork_start(void);
238 void TSA_NO_TSA mmap_fork_end(int child);
239 
240 /* main.c */
241 extern char qemu_proc_pathname[];
242 extern unsigned long target_maxtsiz;
243 extern unsigned long target_dfldsiz;
244 extern unsigned long target_maxdsiz;
245 extern unsigned long target_dflssiz;
246 extern unsigned long target_maxssiz;
247 extern unsigned long target_sgrowsiz;
248 
249 /* os-syscall.c */
250 abi_long get_errno(abi_long ret);
251 bool is_error(abi_long ret);
252 int host_to_target_errno(int err);
253 
254 /* os-proc.c */
255 abi_long freebsd_exec_common(abi_ulong path_or_fd, abi_ulong guest_argp,
256         abi_ulong guest_envp, int do_fexec);
257 abi_long do_freebsd_procctl(void *cpu_env, int idtype, abi_ulong arg2,
258         abi_ulong arg3, abi_ulong arg4, abi_ulong arg5, abi_ulong arg6);
259 
260 /* os-sys.c */
261 abi_long do_freebsd_sysctl(CPUArchState *env, abi_ulong namep, int32_t namelen,
262         abi_ulong oldp, abi_ulong oldlenp, abi_ulong newp, abi_ulong newlen);
263 abi_long do_freebsd_sysctlbyname(CPUArchState *env, abi_ulong namep,
264         int32_t namelen, abi_ulong oldp, abi_ulong oldlenp, abi_ulong newp,
265         abi_ulong newlen);
266 abi_long do_freebsd_sysarch(void *cpu_env, abi_long arg1, abi_long arg2);
267 
268 /* user access */
269 
270 #define VERIFY_READ  PAGE_READ
271 #define VERIFY_WRITE (PAGE_READ | PAGE_WRITE)
272 
273 static inline bool access_ok(int type, abi_ulong addr, abi_ulong size)
274 {
275     return page_check_range((target_ulong)addr, size, type);
276 }
277 
278 /*
279  * NOTE __get_user and __put_user use host pointers and don't check access.
280  *
281  * These are usually used to access struct data members once the struct has been
282  * locked - usually with lock_user_struct().
283  */
284 
285 /*
286  * Tricky points:
287  * - Use __builtin_choose_expr to avoid type promotion from ?:,
288  * - Invalid sizes result in a compile time error stemming from
289  *   the fact that abort has no parameters.
290  * - It's easier to use the endian-specific unaligned load/store
291  *   functions than host-endian unaligned load/store plus tswapN.
292  * - The pragmas are necessary only to silence a clang false-positive
293  *   warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
294  * - gcc has bugs in its _Pragma() support in some versions, eg
295  *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
296  *   include the warning-suppression pragmas for clang
297  */
298 #if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
299 #define PRAGMA_DISABLE_PACKED_WARNING                                   \
300     _Pragma("GCC diagnostic push");                                     \
301     _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")
302 
303 #define PRAGMA_REENABLE_PACKED_WARNING          \
304     _Pragma("GCC diagnostic pop")
305 
306 #else
307 #define PRAGMA_DISABLE_PACKED_WARNING
308 #define PRAGMA_REENABLE_PACKED_WARNING
309 #endif
310 
311 #define __put_user_e(x, hptr, e)                                            \
312     do {                                                                    \
313         PRAGMA_DISABLE_PACKED_WARNING;                                      \
314         (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                 \
315         __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,            \
316         __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,            \
317         __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))  \
318             ((hptr), (x)), (void)0);                                        \
319         PRAGMA_REENABLE_PACKED_WARNING;                                     \
320     } while (0)
321 
322 #define __get_user_e(x, hptr, e)                                            \
323     do {                                                                    \
324         PRAGMA_DISABLE_PACKED_WARNING;                                      \
325         ((x) = (typeof(*hptr))(                                             \
326         __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                 \
327         __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,           \
328         __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,            \
329         __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))  \
330             (hptr)), (void)0);                                              \
331         PRAGMA_REENABLE_PACKED_WARNING;                                     \
332     } while (0)
333 
334 
335 #if TARGET_BIG_ENDIAN
336 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
337 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
338 #else
339 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
340 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
341 #endif
342 
343 /*
344  * put_user()/get_user() take a guest address and check access
345  *
346  * These are usually used to access an atomic data type, such as an int, that
347  * has been passed by address.  These internally perform locking and unlocking
348  * on the data type.
349  */
350 #define put_user(x, gaddr, target_type)                                 \
351 ({                                                                      \
352     abi_ulong __gaddr = (gaddr);                                        \
353     target_type *__hptr;                                                \
354     abi_long __ret = 0;                                                 \
355     __hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0);  \
356     if (__hptr) {                                                       \
357         __put_user((x), __hptr);                                        \
358         unlock_user(__hptr, __gaddr, sizeof(target_type));              \
359     } else                                                              \
360         __ret = -TARGET_EFAULT;                                         \
361     __ret;                                                              \
362 })
363 
364 #define get_user(x, gaddr, target_type)                                 \
365 ({                                                                      \
366     abi_ulong __gaddr = (gaddr);                                        \
367     target_type *__hptr;                                                \
368     abi_long __ret = 0;                                                 \
369     __hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1);   \
370     if (__hptr) {                                                       \
371         __get_user((x), __hptr);                                        \
372         unlock_user(__hptr, __gaddr, 0);                                \
373     } else {                                                            \
374         (x) = 0;                                                        \
375         __ret = -TARGET_EFAULT;                                         \
376     }                                                                   \
377     __ret;                                                              \
378 })
379 
380 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
381 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
382 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
383 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
384 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
385 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
386 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
387 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
388 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
389 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
390 
391 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
392 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
393 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
394 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
395 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
396 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
397 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
398 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
399 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
400 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
401 
402 /*
403  * copy_from_user() and copy_to_user() are usually used to copy data
404  * buffers between the target and host.  These internally perform
405  * locking/unlocking of the memory.
406  */
407 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
408 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
409 
410 /*
411  * Functions for accessing guest memory.  The tget and tput functions
412  * read/write single values, byteswapping as necessary.  The lock_user function
413  * gets a pointer to a contiguous area of guest memory, but does not perform
414  * any byteswapping.  lock_user may return either a pointer to the guest
415  * memory, or a temporary buffer.
416  */
417 
418 /*
419  * Lock an area of guest memory into the host.  If copy is true then the
420  * host area will have the same contents as the guest.
421  */
422 static inline void *lock_user(int type, abi_ulong guest_addr, long len,
423                               int copy)
424 {
425     if (!access_ok(type, guest_addr, len)) {
426         return NULL;
427     }
428 #ifdef DEBUG_REMAP
429     {
430         void *addr;
431         addr = g_malloc(len);
432         if (copy) {
433             memcpy(addr, g2h_untagged(guest_addr), len);
434         } else {
435             memset(addr, 0, len);
436         }
437         return addr;
438     }
439 #else
440     return g2h_untagged(guest_addr);
441 #endif
442 }
443 
444 /*
445  * Unlock an area of guest memory.  The first LEN bytes must be flushed back to
446  * guest memory. host_ptr = NULL is explicitly allowed and does nothing.
447  */
448 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
449                                long len)
450 {
451 
452 #ifdef DEBUG_REMAP
453     if (!host_ptr) {
454         return;
455     }
456     if (host_ptr == g2h_untagged(guest_addr)) {
457         return;
458     }
459     if (len > 0) {
460         memcpy(g2h_untagged(guest_addr), host_ptr, len);
461     }
462     g_free(host_ptr);
463 #endif
464 }
465 
466 /*
467  * Return the length of a string in target memory or -TARGET_EFAULT if access
468  * error.
469  */
470 abi_long target_strlen(abi_ulong gaddr);
471 
472 /* Like lock_user but for null terminated strings.  */
473 static inline void *lock_user_string(abi_ulong guest_addr)
474 {
475     abi_long len;
476     len = target_strlen(guest_addr);
477     if (len < 0) {
478         return NULL;
479     }
480     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
481 }
482 
483 /* Helper macros for locking/unlocking a target struct.  */
484 #define lock_user_struct(type, host_ptr, guest_addr, copy)      \
485     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
486 #define unlock_user_struct(host_ptr, guest_addr, copy)          \
487     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
488 
489 static inline uint64_t target_arg64(uint32_t word0, uint32_t word1)
490 {
491 #if TARGET_ABI_BITS == 32
492 #if TARGET_BIG_ENDIAN
493     return ((uint64_t)word0 << 32) | word1;
494 #else
495     return ((uint64_t)word1 << 32) | word0;
496 #endif
497 #else /* TARGET_ABI_BITS != 32 */
498     return word0;
499 #endif /* TARGET_ABI_BITS != 32 */
500 }
501 
502 #include <pthread.h>
503 
504 #include "user/safe-syscall.h"
505 
506 #endif /* QEMU_H */
507