xref: /openbmc/qemu/bsd-user/qemu.h (revision e4e5cb4a)
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 static inline TaskState *get_task_state(CPUState *cs)
121 {
122     return cs->opaque;
123 }
124 
125 void stop_all_tasks(void);
126 extern const char *interp_prefix;
127 extern const char *qemu_uname_release;
128 
129 /*
130  * TARGET_ARG_MAX defines the number of bytes allocated for arguments
131  * and envelope for the new program. 256k should suffice for a reasonable
132  * maximum env+arg in 32-bit environments, bump it up to 512k for !ILP32
133  * platforms.
134  */
135 #if TARGET_ABI_BITS > 32
136 #define TARGET_ARG_MAX (512 * KiB)
137 #else
138 #define TARGET_ARG_MAX (256 * KiB)
139 #endif
140 #define MAX_ARG_PAGES (TARGET_ARG_MAX / TARGET_PAGE_SIZE)
141 
142 /*
143  * This structure is used to hold the arguments that are
144  * used when loading binaries.
145  */
146 struct bsd_binprm {
147         char buf[128];
148         void *page[MAX_ARG_PAGES];
149         abi_ulong p;
150         abi_ulong stringp;
151         int fd;
152         int e_uid, e_gid;
153         int argc, envc;
154         char **argv;
155         char **envp;
156         char *filename;         /* (Given) Name of binary */
157         char *fullpath;         /* Full path of binary */
158         int (*core_dump)(int, CPUArchState *);
159 };
160 
161 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
162 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
163                               abi_ulong stringp);
164 int loader_exec(const char *filename, char **argv, char **envp,
165                 struct target_pt_regs *regs, struct image_info *infop,
166                 struct bsd_binprm *bprm);
167 
168 int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
169                     struct image_info *info);
170 int load_flt_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
171                     struct image_info *info);
172 int is_target_elf_binary(int fd);
173 
174 abi_long memcpy_to_target(abi_ulong dest, const void *src,
175                           unsigned long len);
176 void target_set_brk(abi_ulong new_brk);
177 abi_long do_brk(abi_ulong new_brk);
178 void syscall_init(void);
179 abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1,
180                             abi_long arg2, abi_long arg3, abi_long arg4,
181                             abi_long arg5, abi_long arg6, abi_long arg7,
182                             abi_long arg8);
183 abi_long do_netbsd_syscall(void *cpu_env, int num, abi_long arg1,
184                            abi_long arg2, abi_long arg3, abi_long arg4,
185                            abi_long arg5, abi_long arg6);
186 abi_long do_openbsd_syscall(void *cpu_env, int num, abi_long arg1,
187                             abi_long arg2, abi_long arg3, abi_long arg4,
188                             abi_long arg5, abi_long arg6);
189 void gemu_log(const char *fmt, ...) G_GNUC_PRINTF(1, 2);
190 extern __thread CPUState *thread_cpu;
191 void cpu_loop(CPUArchState *env);
192 char *target_strerror(int err);
193 int get_osversion(void);
194 void fork_start(void);
195 void fork_end(int child);
196 
197 #include "qemu/log.h"
198 
199 /* strace.c */
200 struct syscallname {
201     int nr;
202     const char *name;
203     const char *format;
204     void (*call)(const struct syscallname *,
205                  abi_long, abi_long, abi_long,
206                  abi_long, abi_long, abi_long);
207     void (*result)(const struct syscallname *, abi_long);
208 };
209 
210 void
211 print_freebsd_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_freebsd_syscall_ret(int num, abi_long ret);
215 void
216 print_netbsd_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_netbsd_syscall_ret(int num, abi_long ret);
220 void
221 print_openbsd_syscall(int num,
222                       abi_long arg1, abi_long arg2, abi_long arg3,
223                       abi_long arg4, abi_long arg5, abi_long arg6);
224 void print_openbsd_syscall_ret(int num, abi_long ret);
225 /**
226  * print_taken_signal:
227  * @target_signum: target signal being taken
228  * @tinfo: target_siginfo_t which will be passed to the guest for the signal
229  *
230  * Print strace output indicating that this signal is being taken by the guest,
231  * in a format similar to:
232  * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
233  */
234 void print_taken_signal(int target_signum, const target_siginfo_t *tinfo);
235 extern int do_strace;
236 
237 /* mmap.c */
238 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
239 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
240                      int flags, int fd, off_t offset);
241 int target_munmap(abi_ulong start, abi_ulong len);
242 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
243                        abi_ulong new_size, unsigned long flags,
244                        abi_ulong new_addr);
245 int target_msync(abi_ulong start, abi_ulong len, int flags);
246 extern abi_ulong mmap_next_start;
247 abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size);
248 void mmap_reserve(abi_ulong start, abi_ulong size);
249 void TSA_NO_TSA mmap_fork_start(void);
250 void TSA_NO_TSA mmap_fork_end(int child);
251 
252 /* main.c */
253 extern char qemu_proc_pathname[];
254 extern unsigned long target_maxtsiz;
255 extern unsigned long target_dfldsiz;
256 extern unsigned long target_maxdsiz;
257 extern unsigned long target_dflssiz;
258 extern unsigned long target_maxssiz;
259 extern unsigned long target_sgrowsiz;
260 
261 /* os-syscall.c */
262 abi_long get_errno(abi_long ret);
263 bool is_error(abi_long ret);
264 int host_to_target_errno(int err);
265 
266 /* os-proc.c */
267 abi_long freebsd_exec_common(abi_ulong path_or_fd, abi_ulong guest_argp,
268         abi_ulong guest_envp, int do_fexec);
269 abi_long do_freebsd_procctl(void *cpu_env, int idtype, abi_ulong arg2,
270         abi_ulong arg3, abi_ulong arg4, abi_ulong arg5, abi_ulong arg6);
271 
272 /* os-sys.c */
273 abi_long do_freebsd_sysctl(CPUArchState *env, abi_ulong namep, int32_t namelen,
274         abi_ulong oldp, abi_ulong oldlenp, abi_ulong newp, abi_ulong newlen);
275 abi_long do_freebsd_sysctlbyname(CPUArchState *env, abi_ulong namep,
276         int32_t namelen, abi_ulong oldp, abi_ulong oldlenp, abi_ulong newp,
277         abi_ulong newlen);
278 abi_long do_freebsd_sysarch(void *cpu_env, abi_long arg1, abi_long arg2);
279 
280 /* user access */
281 
282 #define VERIFY_READ  PAGE_READ
283 #define VERIFY_WRITE (PAGE_READ | PAGE_WRITE)
284 
285 static inline bool access_ok(int type, abi_ulong addr, abi_ulong size)
286 {
287     return page_check_range((target_ulong)addr, size, type);
288 }
289 
290 /*
291  * NOTE __get_user and __put_user use host pointers and don't check access.
292  *
293  * These are usually used to access struct data members once the struct has been
294  * locked - usually with lock_user_struct().
295  */
296 
297 /*
298  * Tricky points:
299  * - Use __builtin_choose_expr to avoid type promotion from ?:,
300  * - Invalid sizes result in a compile time error stemming from
301  *   the fact that abort has no parameters.
302  * - It's easier to use the endian-specific unaligned load/store
303  *   functions than host-endian unaligned load/store plus tswapN.
304  * - The pragmas are necessary only to silence a clang false-positive
305  *   warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
306  * - gcc has bugs in its _Pragma() support in some versions, eg
307  *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
308  *   include the warning-suppression pragmas for clang
309  */
310 #if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
311 #define PRAGMA_DISABLE_PACKED_WARNING                                   \
312     _Pragma("GCC diagnostic push");                                     \
313     _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")
314 
315 #define PRAGMA_REENABLE_PACKED_WARNING          \
316     _Pragma("GCC diagnostic pop")
317 
318 #else
319 #define PRAGMA_DISABLE_PACKED_WARNING
320 #define PRAGMA_REENABLE_PACKED_WARNING
321 #endif
322 
323 #define __put_user_e(x, hptr, e)                                            \
324     do {                                                                    \
325         PRAGMA_DISABLE_PACKED_WARNING;                                      \
326         (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                 \
327         __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,            \
328         __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,            \
329         __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))  \
330             ((hptr), (x)), (void)0);                                        \
331         PRAGMA_REENABLE_PACKED_WARNING;                                     \
332     } while (0)
333 
334 #define __get_user_e(x, hptr, e)                                            \
335     do {                                                                    \
336         PRAGMA_DISABLE_PACKED_WARNING;                                      \
337         ((x) = (typeof(*hptr))(                                             \
338         __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                 \
339         __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,           \
340         __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,            \
341         __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))  \
342             (hptr)), (void)0);                                              \
343         PRAGMA_REENABLE_PACKED_WARNING;                                     \
344     } while (0)
345 
346 
347 #if TARGET_BIG_ENDIAN
348 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
349 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
350 #else
351 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
352 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
353 #endif
354 
355 /*
356  * put_user()/get_user() take a guest address and check access
357  *
358  * These are usually used to access an atomic data type, such as an int, that
359  * has been passed by address.  These internally perform locking and unlocking
360  * on the data type.
361  */
362 #define put_user(x, gaddr, target_type)                                 \
363 ({                                                                      \
364     abi_ulong __gaddr = (gaddr);                                        \
365     target_type *__hptr;                                                \
366     abi_long __ret = 0;                                                 \
367     __hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0);  \
368     if (__hptr) {                                                       \
369         __put_user((x), __hptr);                                        \
370         unlock_user(__hptr, __gaddr, sizeof(target_type));              \
371     } else                                                              \
372         __ret = -TARGET_EFAULT;                                         \
373     __ret;                                                              \
374 })
375 
376 #define get_user(x, gaddr, target_type)                                 \
377 ({                                                                      \
378     abi_ulong __gaddr = (gaddr);                                        \
379     target_type *__hptr;                                                \
380     abi_long __ret = 0;                                                 \
381     __hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1);   \
382     if (__hptr) {                                                       \
383         __get_user((x), __hptr);                                        \
384         unlock_user(__hptr, __gaddr, 0);                                \
385     } else {                                                            \
386         (x) = 0;                                                        \
387         __ret = -TARGET_EFAULT;                                         \
388     }                                                                   \
389     __ret;                                                              \
390 })
391 
392 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
393 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
394 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
395 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
396 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
397 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
398 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
399 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
400 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
401 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
402 
403 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
404 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
405 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
406 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
407 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
408 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
409 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
410 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
411 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
412 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
413 
414 /*
415  * copy_from_user() and copy_to_user() are usually used to copy data
416  * buffers between the target and host.  These internally perform
417  * locking/unlocking of the memory.
418  */
419 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
420 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
421 
422 /*
423  * Functions for accessing guest memory.  The tget and tput functions
424  * read/write single values, byteswapping as necessary.  The lock_user function
425  * gets a pointer to a contiguous area of guest memory, but does not perform
426  * any byteswapping.  lock_user may return either a pointer to the guest
427  * memory, or a temporary buffer.
428  */
429 
430 /*
431  * Lock an area of guest memory into the host.  If copy is true then the
432  * host area will have the same contents as the guest.
433  */
434 static inline void *lock_user(int type, abi_ulong guest_addr, long len,
435                               int copy)
436 {
437     if (!access_ok(type, guest_addr, len)) {
438         return NULL;
439     }
440 #ifdef DEBUG_REMAP
441     {
442         void *addr;
443         addr = g_malloc(len);
444         if (copy) {
445             memcpy(addr, g2h_untagged(guest_addr), len);
446         } else {
447             memset(addr, 0, len);
448         }
449         return addr;
450     }
451 #else
452     return g2h_untagged(guest_addr);
453 #endif
454 }
455 
456 /*
457  * Unlock an area of guest memory.  The first LEN bytes must be flushed back to
458  * guest memory. host_ptr = NULL is explicitly allowed and does nothing.
459  */
460 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
461                                long len)
462 {
463 
464 #ifdef DEBUG_REMAP
465     if (!host_ptr) {
466         return;
467     }
468     if (host_ptr == g2h_untagged(guest_addr)) {
469         return;
470     }
471     if (len > 0) {
472         memcpy(g2h_untagged(guest_addr), host_ptr, len);
473     }
474     g_free(host_ptr);
475 #endif
476 }
477 
478 /*
479  * Return the length of a string in target memory or -TARGET_EFAULT if access
480  * error.
481  */
482 abi_long target_strlen(abi_ulong gaddr);
483 
484 /* Like lock_user but for null terminated strings.  */
485 static inline void *lock_user_string(abi_ulong guest_addr)
486 {
487     abi_long len;
488     len = target_strlen(guest_addr);
489     if (len < 0) {
490         return NULL;
491     }
492     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
493 }
494 
495 /* Helper macros for locking/unlocking a target struct.  */
496 #define lock_user_struct(type, host_ptr, guest_addr, copy)      \
497     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
498 #define unlock_user_struct(host_ptr, guest_addr, copy)          \
499     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
500 
501 static inline uint64_t target_arg64(uint32_t word0, uint32_t word1)
502 {
503 #if TARGET_ABI_BITS == 32
504 #if TARGET_BIG_ENDIAN
505     return ((uint64_t)word0 << 32) | word1;
506 #else
507     return ((uint64_t)word1 << 32) | word0;
508 #endif
509 #else /* TARGET_ABI_BITS != 32 */
510     return word0;
511 #endif /* TARGET_ABI_BITS != 32 */
512 }
513 
514 #include <pthread.h>
515 
516 #include "user/safe-syscall.h"
517 
518 #endif /* QEMU_H */
519