balloon: Don't balloon roms
[qemu.git] / util / oslib-posix.c
1 /*
2 * os-posix-lib.c
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2010 Red Hat, Inc.
6 *
7 * QEMU library functions on POSIX which are shared between QEMU and
8 * the QEMU tools.
9 *
10 * Permission is hereby granted, free of charge, to any person obtaining a copy
11 * of this software and associated documentation files (the "Software"), to deal
12 * in the Software without restriction, including without limitation the rights
13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the Software is
15 * furnished to do so, subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26 * THE SOFTWARE.
27 */
28
29 #include "qemu/osdep.h"
30 #include <termios.h>
31
32 #include <glib/gprintf.h>
33
34 #include "sysemu/sysemu.h"
35 #include "trace.h"
36 #include "qapi/error.h"
37 #include "qemu/sockets.h"
38 #include <libgen.h>
39 #include <sys/signal.h>
40 #include "qemu/cutils.h"
41
42 #ifdef CONFIG_LINUX
43 #include <sys/syscall.h>
44 #endif
45
46 #ifdef __FreeBSD__
47 #include <sys/sysctl.h>
48 #include <sys/user.h>
49 #include <libutil.h>
50 #endif
51
52 #include "qemu/mmap-alloc.h"
53
54 #ifdef CONFIG_DEBUG_STACK_USAGE
55 #include "qemu/error-report.h"
56 #endif
57
58 int qemu_get_thread_id(void)
59 {
60 #if defined(__linux__)
61 return syscall(SYS_gettid);
62 #else
63 return getpid();
64 #endif
65 }
66
67 int qemu_daemon(int nochdir, int noclose)
68 {
69 return daemon(nochdir, noclose);
70 }
71
72 void *qemu_oom_check(void *ptr)
73 {
74 if (ptr == NULL) {
75 fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
76 abort();
77 }
78 return ptr;
79 }
80
81 void *qemu_try_memalign(size_t alignment, size_t size)
82 {
83 void *ptr;
84
85 if (alignment < sizeof(void*)) {
86 alignment = sizeof(void*);
87 }
88
89 #if defined(_POSIX_C_SOURCE) && !defined(__sun__)
90 int ret;
91 ret = posix_memalign(&ptr, alignment, size);
92 if (ret != 0) {
93 errno = ret;
94 ptr = NULL;
95 }
96 #elif defined(CONFIG_BSD)
97 ptr = valloc(size);
98 #else
99 ptr = memalign(alignment, size);
100 #endif
101 trace_qemu_memalign(alignment, size, ptr);
102 return ptr;
103 }
104
105 void *qemu_memalign(size_t alignment, size_t size)
106 {
107 return qemu_oom_check(qemu_try_memalign(alignment, size));
108 }
109
110 /* alloc shared memory pages */
111 void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment)
112 {
113 size_t align = QEMU_VMALLOC_ALIGN;
114 void *ptr = qemu_ram_mmap(-1, size, align, false);
115
116 if (ptr == MAP_FAILED) {
117 return NULL;
118 }
119
120 if (alignment) {
121 *alignment = align;
122 }
123
124 trace_qemu_anon_ram_alloc(size, ptr);
125 return ptr;
126 }
127
128 void qemu_vfree(void *ptr)
129 {
130 trace_qemu_vfree(ptr);
131 free(ptr);
132 }
133
134 void qemu_anon_ram_free(void *ptr, size_t size)
135 {
136 trace_qemu_anon_ram_free(ptr, size);
137 qemu_ram_munmap(ptr, size);
138 }
139
140 void qemu_set_block(int fd)
141 {
142 int f;
143 f = fcntl(fd, F_GETFL);
144 fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
145 }
146
147 void qemu_set_nonblock(int fd)
148 {
149 int f;
150 f = fcntl(fd, F_GETFL);
151 fcntl(fd, F_SETFL, f | O_NONBLOCK);
152 }
153
154 int socket_set_fast_reuse(int fd)
155 {
156 int val = 1, ret;
157
158 ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
159 (const char *)&val, sizeof(val));
160
161 assert(ret == 0);
162
163 return ret;
164 }
165
166 void qemu_set_cloexec(int fd)
167 {
168 int f;
169 f = fcntl(fd, F_GETFD);
170 fcntl(fd, F_SETFD, f | FD_CLOEXEC);
171 }
172
173 /*
174 * Creates a pipe with FD_CLOEXEC set on both file descriptors
175 */
176 int qemu_pipe(int pipefd[2])
177 {
178 int ret;
179
180 #ifdef CONFIG_PIPE2
181 ret = pipe2(pipefd, O_CLOEXEC);
182 if (ret != -1 || errno != ENOSYS) {
183 return ret;
184 }
185 #endif
186 ret = pipe(pipefd);
187 if (ret == 0) {
188 qemu_set_cloexec(pipefd[0]);
189 qemu_set_cloexec(pipefd[1]);
190 }
191
192 return ret;
193 }
194
195 int qemu_utimens(const char *path, const struct timespec *times)
196 {
197 struct timeval tv[2], tv_now;
198 struct stat st;
199 int i;
200 #ifdef CONFIG_UTIMENSAT
201 int ret;
202
203 ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW);
204 if (ret != -1 || errno != ENOSYS) {
205 return ret;
206 }
207 #endif
208 /* Fallback: use utimes() instead of utimensat() */
209
210 /* happy if special cases */
211 if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) {
212 return 0;
213 }
214 if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) {
215 return utimes(path, NULL);
216 }
217
218 /* prepare for hard cases */
219 if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) {
220 gettimeofday(&tv_now, NULL);
221 }
222 if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) {
223 stat(path, &st);
224 }
225
226 for (i = 0; i < 2; i++) {
227 if (times[i].tv_nsec == UTIME_NOW) {
228 tv[i].tv_sec = tv_now.tv_sec;
229 tv[i].tv_usec = tv_now.tv_usec;
230 } else if (times[i].tv_nsec == UTIME_OMIT) {
231 tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;
232 tv[i].tv_usec = 0;
233 } else {
234 tv[i].tv_sec = times[i].tv_sec;
235 tv[i].tv_usec = times[i].tv_nsec / 1000;
236 }
237 }
238
239 return utimes(path, &tv[0]);
240 }
241
242 char *
243 qemu_get_local_state_pathname(const char *relative_pathname)
244 {
245 return g_strdup_printf("%s/%s", CONFIG_QEMU_LOCALSTATEDIR,
246 relative_pathname);
247 }
248
249 void qemu_set_tty_echo(int fd, bool echo)
250 {
251 struct termios tty;
252
253 tcgetattr(fd, &tty);
254
255 if (echo) {
256 tty.c_lflag |= ECHO | ECHONL | ICANON | IEXTEN;
257 } else {
258 tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);
259 }
260
261 tcsetattr(fd, TCSANOW, &tty);
262 }
263
264 static char exec_dir[PATH_MAX];
265
266 void qemu_init_exec_dir(const char *argv0)
267 {
268 char *dir;
269 char *p = NULL;
270 char buf[PATH_MAX];
271
272 assert(!exec_dir[0]);
273
274 #if defined(__linux__)
275 {
276 int len;
277 len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
278 if (len > 0) {
279 buf[len] = 0;
280 p = buf;
281 }
282 }
283 #elif defined(__FreeBSD__)
284 {
285 static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
286 size_t len = sizeof(buf) - 1;
287
288 *buf = '\0';
289 if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
290 *buf) {
291 buf[sizeof(buf) - 1] = '\0';
292 p = buf;
293 }
294 }
295 #endif
296 /* If we don't have any way of figuring out the actual executable
297 location then try argv[0]. */
298 if (!p) {
299 if (!argv0) {
300 return;
301 }
302 p = realpath(argv0, buf);
303 if (!p) {
304 return;
305 }
306 }
307 dir = g_path_get_dirname(p);
308
309 pstrcpy(exec_dir, sizeof(exec_dir), dir);
310
311 g_free(dir);
312 }
313
314 char *qemu_get_exec_dir(void)
315 {
316 return g_strdup(exec_dir);
317 }
318
319 static sigjmp_buf sigjump;
320
321 static void sigbus_handler(int signal)
322 {
323 siglongjmp(sigjump, 1);
324 }
325
326 void os_mem_prealloc(int fd, char *area, size_t memory, Error **errp)
327 {
328 int ret;
329 struct sigaction act, oldact;
330 sigset_t set, oldset;
331
332 memset(&act, 0, sizeof(act));
333 act.sa_handler = &sigbus_handler;
334 act.sa_flags = 0;
335
336 ret = sigaction(SIGBUS, &act, &oldact);
337 if (ret) {
338 error_setg_errno(errp, errno,
339 "os_mem_prealloc: failed to install signal handler");
340 return;
341 }
342
343 /* unblock SIGBUS */
344 sigemptyset(&set);
345 sigaddset(&set, SIGBUS);
346 pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
347
348 if (sigsetjmp(sigjump, 1)) {
349 error_setg(errp, "os_mem_prealloc: Insufficient free host memory "
350 "pages available to allocate guest RAM\n");
351 } else {
352 int i;
353 size_t hpagesize = qemu_fd_getpagesize(fd);
354 size_t numpages = DIV_ROUND_UP(memory, hpagesize);
355
356 /* MAP_POPULATE silently ignores failures */
357 for (i = 0; i < numpages; i++) {
358 memset(area + (hpagesize * i), 0, 1);
359 }
360 }
361
362 ret = sigaction(SIGBUS, &oldact, NULL);
363 if (ret) {
364 /* Terminate QEMU since it can't recover from error */
365 perror("os_mem_prealloc: failed to reinstall signal handler");
366 exit(1);
367 }
368 pthread_sigmask(SIG_SETMASK, &oldset, NULL);
369 }
370
371
372 static struct termios oldtty;
373
374 static void term_exit(void)
375 {
376 tcsetattr(0, TCSANOW, &oldtty);
377 }
378
379 static void term_init(void)
380 {
381 struct termios tty;
382
383 tcgetattr(0, &tty);
384 oldtty = tty;
385
386 tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
387 |INLCR|IGNCR|ICRNL|IXON);
388 tty.c_oflag |= OPOST;
389 tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
390 tty.c_cflag &= ~(CSIZE|PARENB);
391 tty.c_cflag |= CS8;
392 tty.c_cc[VMIN] = 1;
393 tty.c_cc[VTIME] = 0;
394
395 tcsetattr(0, TCSANOW, &tty);
396
397 atexit(term_exit);
398 }
399
400 int qemu_read_password(char *buf, int buf_size)
401 {
402 uint8_t ch;
403 int i, ret;
404
405 printf("password: ");
406 fflush(stdout);
407 term_init();
408 i = 0;
409 for (;;) {
410 ret = read(0, &ch, 1);
411 if (ret == -1) {
412 if (errno == EAGAIN || errno == EINTR) {
413 continue;
414 } else {
415 break;
416 }
417 } else if (ret == 0) {
418 ret = -1;
419 break;
420 } else {
421 if (ch == '\r' ||
422 ch == '\n') {
423 ret = 0;
424 break;
425 }
426 if (i < (buf_size - 1)) {
427 buf[i++] = ch;
428 }
429 }
430 }
431 term_exit();
432 buf[i] = '\0';
433 printf("\n");
434 return ret;
435 }
436
437
438 char *qemu_get_pid_name(pid_t pid)
439 {
440 char *name = NULL;
441
442 #if defined(__FreeBSD__)
443 /* BSDs don't have /proc, but they provide a nice substitute */
444 struct kinfo_proc *proc = kinfo_getproc(pid);
445
446 if (proc) {
447 name = g_strdup(proc->ki_comm);
448 free(proc);
449 }
450 #else
451 /* Assume a system with reasonable procfs */
452 char *pid_path;
453 size_t len;
454
455 pid_path = g_strdup_printf("/proc/%d/cmdline", pid);
456 g_file_get_contents(pid_path, &name, &len, NULL);
457 g_free(pid_path);
458 #endif
459
460 return name;
461 }
462
463
464 pid_t qemu_fork(Error **errp)
465 {
466 sigset_t oldmask, newmask;
467 struct sigaction sig_action;
468 int saved_errno;
469 pid_t pid;
470
471 /*
472 * Need to block signals now, so that child process can safely
473 * kill off caller's signal handlers without a race.
474 */
475 sigfillset(&newmask);
476 if (pthread_sigmask(SIG_SETMASK, &newmask, &oldmask) != 0) {
477 error_setg_errno(errp, errno,
478 "cannot block signals");
479 return -1;
480 }
481
482 pid = fork();
483 saved_errno = errno;
484
485 if (pid < 0) {
486 /* attempt to restore signal mask, but ignore failure, to
487 * avoid obscuring the fork failure */
488 (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
489 error_setg_errno(errp, saved_errno,
490 "cannot fork child process");
491 errno = saved_errno;
492 return -1;
493 } else if (pid) {
494 /* parent process */
495
496 /* Restore our original signal mask now that the child is
497 * safely running. Only documented failures are EFAULT (not
498 * possible, since we are using just-grabbed mask) or EINVAL
499 * (not possible, since we are using correct arguments). */
500 (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
501 } else {
502 /* child process */
503 size_t i;
504
505 /* Clear out all signal handlers from parent so nothing
506 * unexpected can happen in our child once we unblock
507 * signals */
508 sig_action.sa_handler = SIG_DFL;
509 sig_action.sa_flags = 0;
510 sigemptyset(&sig_action.sa_mask);
511
512 for (i = 1; i < NSIG; i++) {
513 /* Only possible errors are EFAULT or EINVAL The former
514 * won't happen, the latter we expect, so no need to check
515 * return value */
516 (void)sigaction(i, &sig_action, NULL);
517 }
518
519 /* Unmask all signals in child, since we've no idea what the
520 * caller's done with their signal mask and don't want to
521 * propagate that to children */
522 sigemptyset(&newmask);
523 if (pthread_sigmask(SIG_SETMASK, &newmask, NULL) != 0) {
524 Error *local_err = NULL;
525 error_setg_errno(&local_err, errno,
526 "cannot unblock signals");
527 error_report_err(local_err);
528 _exit(1);
529 }
530 }
531 return pid;
532 }
533
534 void *qemu_alloc_stack(size_t *sz)
535 {
536 void *ptr, *guardpage;
537 #ifdef CONFIG_DEBUG_STACK_USAGE
538 void *ptr2;
539 #endif
540 size_t pagesz = getpagesize();
541 #ifdef _SC_THREAD_STACK_MIN
542 /* avoid stacks smaller than _SC_THREAD_STACK_MIN */
543 long min_stack_sz = sysconf(_SC_THREAD_STACK_MIN);
544 *sz = MAX(MAX(min_stack_sz, 0), *sz);
545 #endif
546 /* adjust stack size to a multiple of the page size */
547 *sz = ROUND_UP(*sz, pagesz);
548 /* allocate one extra page for the guard page */
549 *sz += pagesz;
550
551 ptr = mmap(NULL, *sz, PROT_READ | PROT_WRITE,
552 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
553 if (ptr == MAP_FAILED) {
554 abort();
555 }
556
557 #if defined(HOST_IA64)
558 /* separate register stack */
559 guardpage = ptr + (((*sz - pagesz) / 2) & ~pagesz);
560 #elif defined(HOST_HPPA)
561 /* stack grows up */
562 guardpage = ptr + *sz - pagesz;
563 #else
564 /* stack grows down */
565 guardpage = ptr;
566 #endif
567 if (mprotect(guardpage, pagesz, PROT_NONE) != 0) {
568 abort();
569 }
570
571 #ifdef CONFIG_DEBUG_STACK_USAGE
572 for (ptr2 = ptr + pagesz; ptr2 < ptr + *sz; ptr2 += sizeof(uint32_t)) {
573 *(uint32_t *)ptr2 = 0xdeadbeaf;
574 }
575 #endif
576
577 return ptr;
578 }
579
580 #ifdef CONFIG_DEBUG_STACK_USAGE
581 static __thread unsigned int max_stack_usage;
582 #endif
583
584 void qemu_free_stack(void *stack, size_t sz)
585 {
586 #ifdef CONFIG_DEBUG_STACK_USAGE
587 unsigned int usage;
588 void *ptr;
589
590 for (ptr = stack + getpagesize(); ptr < stack + sz;
591 ptr += sizeof(uint32_t)) {
592 if (*(uint32_t *)ptr != 0xdeadbeaf) {
593 break;
594 }
595 }
596 usage = sz - (uintptr_t) (ptr - stack);
597 if (usage > max_stack_usage) {
598 error_report("thread %d max stack usage increased from %u to %u",
599 qemu_get_thread_id(), max_stack_usage, usage);
600 max_stack_usage = usage;
601 }
602 #endif
603
604 munmap(stack, sz);
605 }