xref: /openbmc/qemu/bsd-user/qemu.h (revision 523e45ac)
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 <sys/param.h>
21 
22 #include "qemu/int128.h"
23 #include "cpu.h"
24 #include "qemu/units.h"
25 #include "exec/cpu_ldst.h"
26 #include "exec/exec-all.h"
27 
28 #include "user/abitypes.h"
29 
30 extern char **environ;
31 
32 #include "user/thunk.h"
33 #include "target_arch.h"
34 #include "syscall_defs.h"
35 #include "target_syscall.h"
36 #include "target_os_vmparam.h"
37 #include "target_os_signal.h"
38 #include "target.h"
39 #include "exec/gdbstub.h"
40 #include "exec/page-protection.h"
41 #include "qemu/clang-tsa.h"
42 #include "accel/tcg/vcpu-state.h"
43 
44 #include "qemu-os.h"
45 /*
46  * TODO: Remove these and rely only on qemu_real_host_page_size().
47  */
48 extern uintptr_t qemu_host_page_size;
49 extern intptr_t qemu_host_page_mask;
50 #define HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_host_page_size)
51 
52 /*
53  * This struct is used to hold certain information about the image.  Basically,
54  * it replicates in user space what would be certain task_struct fields in the
55  * kernel
56  */
57 struct image_info {
58     abi_ulong load_bias;
59     abi_ulong load_addr;
60     abi_ulong start_code;
61     abi_ulong end_code;
62     abi_ulong start_data;
63     abi_ulong end_data;
64     abi_ulong brk;
65     abi_ulong rss;
66     abi_ulong start_stack;
67     abi_ulong entry;
68     abi_ulong code_offset;
69     abi_ulong data_offset;
70     abi_ulong arg_start;
71     abi_ulong arg_end;
72     uint32_t  elf_flags;
73 };
74 
75 struct emulated_sigtable {
76     int pending; /* true if signal is pending */
77     target_siginfo_t info;
78 };
79 
80 /*
81  * NOTE: we force a big alignment so that the stack stored after is aligned too
82  */
83 struct TaskState {
84     pid_t ts_tid;     /* tid (or pid) of this task */
85 
86     struct TaskState *next;
87     struct bsd_binprm *bprm;
88     struct image_info *info;
89 
90     struct emulated_sigtable sync_signal;
91     /*
92      * TODO: Since we block all signals while returning to the main CPU
93      * loop, this needn't be an array
94      */
95     struct emulated_sigtable sigtab[TARGET_NSIG];
96     /*
97      * Nonzero if process_pending_signals() needs to do something (either
98      * handle a pending signal or unblock signals).
99      * This flag is written from a signal handler so should be accessed via
100      * the qatomic_read() and qatomic_set() functions. (It is not accessed
101      * from multiple threads.)
102      */
103     int signal_pending;
104     /* True if we're leaving a sigsuspend and sigsuspend_mask is valid. */
105     bool in_sigsuspend;
106     /*
107      * This thread's signal mask, as requested by the guest program.
108      * The actual signal mask of this thread may differ:
109      *  + we don't let SIGSEGV and SIGBUS be blocked while running guest code
110      *  + sometimes we block all signals to avoid races
111      */
112     sigset_t signal_mask;
113     /*
114      * The signal mask imposed by a guest sigsuspend syscall, if we are
115      * currently in the middle of such a syscall
116      */
117     sigset_t sigsuspend_mask;
118 
119     /* This thread's sigaltstack, if it has one */
120     struct target_sigaltstack sigaltstack_used;
121 } __attribute__((aligned(16)));
122 
123 void stop_all_tasks(void);
124 extern const char *interp_prefix;
125 extern const char *qemu_uname_release;
126 
127 /*
128  * TARGET_ARG_MAX defines the number of bytes allocated for arguments
129  * and envelope for the new program. 256k should suffice for a reasonable
130  * maximum env+arg in 32-bit environments, bump it up to 512k for !ILP32
131  * platforms.
132  */
133 #if TARGET_ABI_BITS > 32
134 #define TARGET_ARG_MAX (512 * KiB)
135 #else
136 #define TARGET_ARG_MAX (256 * KiB)
137 #endif
138 #define MAX_ARG_PAGES (TARGET_ARG_MAX / TARGET_PAGE_SIZE)
139 
140 /*
141  * This structure is used to hold the arguments that are
142  * used when loading binaries.
143  */
144 struct bsd_binprm {
145         char buf[128];
146         void *page[MAX_ARG_PAGES];
147         abi_ulong p;
148         abi_ulong stringp;
149         int fd;
150         int e_uid, e_gid;
151         int argc, envc;
152         char **argv;
153         char **envp;
154         char *filename;         /* (Given) Name of binary */
155         char *fullpath;         /* Full path of binary */
156         int (*core_dump)(int, CPUArchState *);
157 };
158 
159 void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
160 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
161                               abi_ulong stringp);
162 int loader_exec(const char *filename, char **argv, char **envp,
163                 struct target_pt_regs *regs, struct image_info *infop,
164                 struct bsd_binprm *bprm);
165 
166 int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
167                     struct image_info *info);
168 int load_flt_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
169                     struct image_info *info);
170 int is_target_elf_binary(int fd);
171 
172 abi_long memcpy_to_target(abi_ulong dest, const void *src,
173                           unsigned long len);
174 void target_set_brk(abi_ulong new_brk);
175 abi_long do_brk(abi_ulong new_brk);
176 void syscall_init(void);
177 abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1,
178                             abi_long arg2, abi_long arg3, abi_long arg4,
179                             abi_long arg5, abi_long arg6, abi_long arg7,
180                             abi_long arg8);
181 abi_long do_netbsd_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 abi_long do_openbsd_syscall(void *cpu_env, int num, abi_long arg1,
185                             abi_long arg2, abi_long arg3, abi_long arg4,
186                             abi_long arg5, abi_long arg6);
187 void gemu_log(const char *fmt, ...) G_GNUC_PRINTF(1, 2);
188 extern __thread CPUState *thread_cpu;
189 void cpu_loop(CPUArchState *env);
190 char *target_strerror(int err);
191 int get_osversion(void);
192 void fork_start(void);
193 void fork_end(pid_t pid);
194 
195 #include "qemu/log.h"
196 
197 /* strace.c */
198 struct syscallname {
199     int nr;
200     const char *name;
201     const char *format;
202     void (*call)(const struct syscallname *,
203                  abi_long, abi_long, abi_long,
204                  abi_long, abi_long, abi_long);
205     void (*result)(const struct syscallname *, abi_long);
206 };
207 
208 void
209 print_freebsd_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_freebsd_syscall_ret(int num, abi_long ret);
213 void
214 print_netbsd_syscall(int num,
215                      abi_long arg1, abi_long arg2, abi_long arg3,
216                      abi_long arg4, abi_long arg5, abi_long arg6);
217 void print_netbsd_syscall_ret(int num, abi_long ret);
218 void
219 print_openbsd_syscall(int num,
220                       abi_long arg1, abi_long arg2, abi_long arg3,
221                       abi_long arg4, abi_long arg5, abi_long arg6);
222 void print_openbsd_syscall_ret(int num, abi_long ret);
223 /**
224  * print_taken_signal:
225  * @target_signum: target signal being taken
226  * @tinfo: target_siginfo_t which will be passed to the guest for the signal
227  *
228  * Print strace output indicating that this signal is being taken by the guest,
229  * in a format similar to:
230  * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
231  */
232 void print_taken_signal(int target_signum, const target_siginfo_t *tinfo);
233 extern int do_strace;
234 
235 /* mmap.c */
236 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
237 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
238                      int flags, int fd, off_t offset);
239 int target_munmap(abi_ulong start, abi_ulong len);
240 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
241                        abi_ulong new_size, unsigned long flags,
242                        abi_ulong new_addr);
243 int target_msync(abi_ulong start, abi_ulong len, int flags);
244 extern abi_ulong mmap_next_start;
245 abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size);
246 void mmap_reserve(abi_ulong start, abi_ulong size);
247 void TSA_NO_TSA mmap_fork_start(void);
248 void TSA_NO_TSA mmap_fork_end(int child);
249 
250 /* main.c */
251 extern char qemu_proc_pathname[];
252 extern unsigned long target_maxtsiz;
253 extern unsigned long target_dfldsiz;
254 extern unsigned long target_maxdsiz;
255 extern unsigned long target_dflssiz;
256 extern unsigned long target_maxssiz;
257 extern unsigned long target_sgrowsiz;
258 
259 /* os-syscall.c */
260 abi_long get_errno(abi_long ret);
261 bool is_error(abi_long ret);
262 int host_to_target_errno(int err);
263 
264 /* os-proc.c */
265 abi_long freebsd_exec_common(abi_ulong path_or_fd, abi_ulong guest_argp,
266         abi_ulong guest_envp, int do_fexec);
267 abi_long do_freebsd_procctl(void *cpu_env, int idtype, abi_ulong arg2,
268         abi_ulong arg3, abi_ulong arg4, abi_ulong arg5, abi_ulong arg6);
269 
270 /* os-sys.c */
271 abi_long do_freebsd_sysctl(CPUArchState *env, abi_ulong namep, int32_t namelen,
272         abi_ulong oldp, abi_ulong oldlenp, abi_ulong newp, abi_ulong newlen);
273 abi_long do_freebsd_sysctlbyname(CPUArchState *env, abi_ulong namep,
274         int32_t namelen, abi_ulong oldp, abi_ulong oldlenp, abi_ulong newp,
275         abi_ulong newlen);
276 abi_long do_freebsd_sysarch(void *cpu_env, abi_long arg1, abi_long arg2);
277 
278 /* user access */
279 
280 #define VERIFY_READ  PAGE_READ
281 #define VERIFY_WRITE (PAGE_READ | PAGE_WRITE)
282 
283 static inline bool access_ok(int type, abi_ulong addr, abi_ulong size)
284 {
285     return page_check_range((target_ulong)addr, size, type);
286 }
287 
288 /*
289  * NOTE __get_user and __put_user use host pointers and don't check access.
290  *
291  * These are usually used to access struct data members once the struct has been
292  * locked - usually with lock_user_struct().
293  */
294 
295 /*
296  * Tricky points:
297  * - Use __builtin_choose_expr to avoid type promotion from ?:,
298  * - Invalid sizes result in a compile time error stemming from
299  *   the fact that abort has no parameters.
300  * - It's easier to use the endian-specific unaligned load/store
301  *   functions than host-endian unaligned load/store plus tswapN.
302  * - The pragmas are necessary only to silence a clang false-positive
303  *   warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
304  * - gcc has bugs in its _Pragma() support in some versions, eg
305  *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
306  *   include the warning-suppression pragmas for clang
307  */
308 #if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
309 #define PRAGMA_DISABLE_PACKED_WARNING                                   \
310     _Pragma("GCC diagnostic push");                                     \
311     _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")
312 
313 #define PRAGMA_REENABLE_PACKED_WARNING          \
314     _Pragma("GCC diagnostic pop")
315 
316 #else
317 #define PRAGMA_DISABLE_PACKED_WARNING
318 #define PRAGMA_REENABLE_PACKED_WARNING
319 #endif
320 
321 #define __put_user_e(x, hptr, e)                                            \
322     do {                                                                    \
323         PRAGMA_DISABLE_PACKED_WARNING;                                      \
324         (__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p,                 \
325         __builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p,            \
326         __builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p,            \
327         __builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort))))  \
328             ((hptr), (x)), (void)0);                                        \
329         PRAGMA_REENABLE_PACKED_WARNING;                                     \
330     } while (0)
331 
332 #define __get_user_e(x, hptr, e)                                            \
333     do {                                                                    \
334         PRAGMA_DISABLE_PACKED_WARNING;                                      \
335         ((x) = (typeof(*hptr))(                                             \
336         __builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p,                 \
337         __builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p,           \
338         __builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p,            \
339         __builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort))))  \
340             (hptr)), (void)0);                                              \
341         PRAGMA_REENABLE_PACKED_WARNING;                                     \
342     } while (0)
343 
344 
345 #if TARGET_BIG_ENDIAN
346 # define __put_user(x, hptr)  __put_user_e(x, hptr, be)
347 # define __get_user(x, hptr)  __get_user_e(x, hptr, be)
348 #else
349 # define __put_user(x, hptr)  __put_user_e(x, hptr, le)
350 # define __get_user(x, hptr)  __get_user_e(x, hptr, le)
351 #endif
352 
353 /*
354  * put_user()/get_user() take a guest address and check access
355  *
356  * These are usually used to access an atomic data type, such as an int, that
357  * has been passed by address.  These internally perform locking and unlocking
358  * on the data type.
359  */
360 #define put_user(x, gaddr, target_type)                                 \
361 ({                                                                      \
362     abi_ulong __gaddr = (gaddr);                                        \
363     target_type *__hptr;                                                \
364     abi_long __ret = 0;                                                 \
365     __hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0);  \
366     if (__hptr) {                                                       \
367         __put_user((x), __hptr);                                        \
368         unlock_user(__hptr, __gaddr, sizeof(target_type));              \
369     } else                                                              \
370         __ret = -TARGET_EFAULT;                                         \
371     __ret;                                                              \
372 })
373 
374 #define get_user(x, gaddr, target_type)                                 \
375 ({                                                                      \
376     abi_ulong __gaddr = (gaddr);                                        \
377     target_type *__hptr;                                                \
378     abi_long __ret = 0;                                                 \
379     __hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1);   \
380     if (__hptr) {                                                       \
381         __get_user((x), __hptr);                                        \
382         unlock_user(__hptr, __gaddr, 0);                                \
383     } else {                                                            \
384         (x) = 0;                                                        \
385         __ret = -TARGET_EFAULT;                                         \
386     }                                                                   \
387     __ret;                                                              \
388 })
389 
390 #define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
391 #define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
392 #define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
393 #define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
394 #define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
395 #define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
396 #define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
397 #define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
398 #define put_user_u8(x, gaddr)  put_user((x), (gaddr), uint8_t)
399 #define put_user_s8(x, gaddr)  put_user((x), (gaddr), int8_t)
400 
401 #define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
402 #define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
403 #define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
404 #define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
405 #define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
406 #define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
407 #define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
408 #define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
409 #define get_user_u8(x, gaddr)  get_user((x), (gaddr), uint8_t)
410 #define get_user_s8(x, gaddr)  get_user((x), (gaddr), int8_t)
411 
412 /*
413  * copy_from_user() and copy_to_user() are usually used to copy data
414  * buffers between the target and host.  These internally perform
415  * locking/unlocking of the memory.
416  */
417 abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len);
418 abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
419 
420 /*
421  * Functions for accessing guest memory.  The tget and tput functions
422  * read/write single values, byteswapping as necessary.  The lock_user function
423  * gets a pointer to a contiguous area of guest memory, but does not perform
424  * any byteswapping.  lock_user may return either a pointer to the guest
425  * memory, or a temporary buffer.
426  */
427 
428 /*
429  * Lock an area of guest memory into the host.  If copy is true then the
430  * host area will have the same contents as the guest.
431  */
432 static inline void *lock_user(int type, abi_ulong guest_addr, long len,
433                               int copy)
434 {
435     if (!access_ok(type, guest_addr, len)) {
436         return NULL;
437     }
438 #ifdef CONFIG_DEBUG_REMAP
439     {
440         void *addr;
441         addr = g_malloc(len);
442         if (copy) {
443             memcpy(addr, g2h_untagged(guest_addr), len);
444         } else {
445             memset(addr, 0, len);
446         }
447         return addr;
448     }
449 #else
450     return g2h_untagged(guest_addr);
451 #endif
452 }
453 
454 /*
455  * Unlock an area of guest memory.  The first LEN bytes must be flushed back to
456  * guest memory. host_ptr = NULL is explicitly allowed and does nothing.
457  */
458 static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
459                                long len)
460 {
461 
462 #ifdef CONFIG_DEBUG_REMAP
463     if (!host_ptr) {
464         return;
465     }
466     if (host_ptr == g2h_untagged(guest_addr)) {
467         return;
468     }
469     if (len > 0) {
470         memcpy(g2h_untagged(guest_addr), host_ptr, len);
471     }
472     g_free(host_ptr);
473 #endif
474 }
475 
476 /*
477  * Return the length of a string in target memory or -TARGET_EFAULT if access
478  * error.
479  */
480 abi_long target_strlen(abi_ulong gaddr);
481 
482 /* Like lock_user but for null terminated strings.  */
483 static inline void *lock_user_string(abi_ulong guest_addr)
484 {
485     abi_long len;
486     len = target_strlen(guest_addr);
487     if (len < 0) {
488         return NULL;
489     }
490     return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
491 }
492 
493 /* Helper macros for locking/unlocking a target struct.  */
494 #define lock_user_struct(type, host_ptr, guest_addr, copy)      \
495     (host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
496 #define unlock_user_struct(host_ptr, guest_addr, copy)          \
497     unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
498 
499 static inline uint64_t target_arg64(uint32_t word0, uint32_t word1)
500 {
501 #if TARGET_ABI_BITS == 32
502 #if TARGET_BIG_ENDIAN
503     return ((uint64_t)word0 << 32) | word1;
504 #else
505     return ((uint64_t)word1 << 32) | word0;
506 #endif
507 #else /* TARGET_ABI_BITS != 32 */
508     return word0;
509 #endif /* TARGET_ABI_BITS != 32 */
510 }
511 
512 #include <pthread.h>
513 
514 #include "user/safe-syscall.h"
515 
516 #endif /* QEMU_H */
517