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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#ifdef __NetBSD__
53#include <sys/sysctl.h>
54#endif
55
56#include "qemu/mmap-alloc.h"
57
58#ifdef CONFIG_DEBUG_STACK_USAGE
59#include "qemu/error-report.h"
60#endif
61
62#define MAX_MEM_PREALLOC_THREAD_COUNT 16
63
64struct MemsetThread {
65 char *addr;
66 size_t numpages;
67 size_t hpagesize;
68 QemuThread pgthread;
69 sigjmp_buf env;
70};
71typedef struct MemsetThread MemsetThread;
72
73static MemsetThread *memset_thread;
74static int memset_num_threads;
75static bool memset_thread_failed;
76
77int qemu_get_thread_id(void)
78{
79#if defined(__linux__)
80 return syscall(SYS_gettid);
81#else
82 return getpid();
83#endif
84}
85
86int qemu_daemon(int nochdir, int noclose)
87{
88 return daemon(nochdir, noclose);
89}
90
91bool qemu_write_pidfile(const char *path, Error **errp)
92{
93 int fd;
94 char pidstr[32];
95
96 while (1) {
97 struct stat a, b;
98 struct flock lock = {
99 .l_type = F_WRLCK,
100 .l_whence = SEEK_SET,
101 .l_len = 0,
102 };
103
104 fd = qemu_open(path, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR);
105 if (fd == -1) {
106 error_setg_errno(errp, errno, "Cannot open pid file");
107 return false;
108 }
109
110 if (fstat(fd, &b) < 0) {
111 error_setg_errno(errp, errno, "Cannot stat file");
112 goto fail_close;
113 }
114
115 if (fcntl(fd, F_SETLK, &lock)) {
116 error_setg_errno(errp, errno, "Cannot lock pid file");
117 goto fail_close;
118 }
119
120
121
122
123
124 if (stat(path, &a) < 0) {
125
126
127
128
129 close(fd);
130 continue;
131 }
132
133 if (a.st_ino == b.st_ino) {
134 break;
135 }
136
137
138
139
140
141 close(fd);
142 }
143
144 if (ftruncate(fd, 0) < 0) {
145 error_setg_errno(errp, errno, "Failed to truncate pid file");
146 goto fail_unlink;
147 }
148
149 snprintf(pidstr, sizeof(pidstr), FMT_pid "\n", getpid());
150 if (write(fd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
151 error_setg(errp, "Failed to write pid file");
152 goto fail_unlink;
153 }
154
155 return true;
156
157fail_unlink:
158 unlink(path);
159fail_close:
160 close(fd);
161 return false;
162}
163
164void *qemu_oom_check(void *ptr)
165{
166 if (ptr == NULL) {
167 fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
168 abort();
169 }
170 return ptr;
171}
172
173void *qemu_try_memalign(size_t alignment, size_t size)
174{
175 void *ptr;
176
177 if (alignment < sizeof(void*)) {
178 alignment = sizeof(void*);
179 }
180
181#if defined(CONFIG_POSIX_MEMALIGN)
182 int ret;
183 ret = posix_memalign(&ptr, alignment, size);
184 if (ret != 0) {
185 errno = ret;
186 ptr = NULL;
187 }
188#elif defined(CONFIG_BSD)
189 ptr = valloc(size);
190#else
191 ptr = memalign(alignment, size);
192#endif
193 trace_qemu_memalign(alignment, size, ptr);
194 return ptr;
195}
196
197void *qemu_memalign(size_t alignment, size_t size)
198{
199 return qemu_oom_check(qemu_try_memalign(alignment, size));
200}
201
202
203void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared)
204{
205 size_t align = QEMU_VMALLOC_ALIGN;
206 void *ptr = qemu_ram_mmap(-1, size, align, shared);
207
208 if (ptr == MAP_FAILED) {
209 return NULL;
210 }
211
212 if (alignment) {
213 *alignment = align;
214 }
215
216 trace_qemu_anon_ram_alloc(size, ptr);
217 return ptr;
218}
219
220void qemu_vfree(void *ptr)
221{
222 trace_qemu_vfree(ptr);
223 free(ptr);
224}
225
226void qemu_anon_ram_free(void *ptr, size_t size)
227{
228 trace_qemu_anon_ram_free(ptr, size);
229 qemu_ram_munmap(ptr, size);
230}
231
232void qemu_set_block(int fd)
233{
234 int f;
235 f = fcntl(fd, F_GETFL);
236 fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
237}
238
239void qemu_set_nonblock(int fd)
240{
241 int f;
242 f = fcntl(fd, F_GETFL);
243 fcntl(fd, F_SETFL, f | O_NONBLOCK);
244}
245
246int socket_set_fast_reuse(int fd)
247{
248 int val = 1, ret;
249
250 ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
251 (const char *)&val, sizeof(val));
252
253 assert(ret == 0);
254
255 return ret;
256}
257
258void qemu_set_cloexec(int fd)
259{
260 int f;
261 f = fcntl(fd, F_GETFD);
262 assert(f != -1);
263 f = fcntl(fd, F_SETFD, f | FD_CLOEXEC);
264 assert(f != -1);
265}
266
267
268
269
270int qemu_pipe(int pipefd[2])
271{
272 int ret;
273
274#ifdef CONFIG_PIPE2
275 ret = pipe2(pipefd, O_CLOEXEC);
276 if (ret != -1 || errno != ENOSYS) {
277 return ret;
278 }
279#endif
280 ret = pipe(pipefd);
281 if (ret == 0) {
282 qemu_set_cloexec(pipefd[0]);
283 qemu_set_cloexec(pipefd[1]);
284 }
285
286 return ret;
287}
288
289char *
290qemu_get_local_state_pathname(const char *relative_pathname)
291{
292 return g_strdup_printf("%s/%s", CONFIG_QEMU_LOCALSTATEDIR,
293 relative_pathname);
294}
295
296void qemu_set_tty_echo(int fd, bool echo)
297{
298 struct termios tty;
299
300 tcgetattr(fd, &tty);
301
302 if (echo) {
303 tty.c_lflag |= ECHO | ECHONL | ICANON | IEXTEN;
304 } else {
305 tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);
306 }
307
308 tcsetattr(fd, TCSANOW, &tty);
309}
310
311static char exec_dir[PATH_MAX];
312
313void qemu_init_exec_dir(const char *argv0)
314{
315 char *dir;
316 char *p = NULL;
317 char buf[PATH_MAX];
318
319 assert(!exec_dir[0]);
320
321#if defined(__linux__)
322 {
323 int len;
324 len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
325 if (len > 0) {
326 buf[len] = 0;
327 p = buf;
328 }
329 }
330#elif defined(__FreeBSD__) \
331 || (defined(__NetBSD__) && defined(KERN_PROC_PATHNAME))
332 {
333#if defined(__FreeBSD__)
334 static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
335#else
336 static int mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
337#endif
338 size_t len = sizeof(buf) - 1;
339
340 *buf = '\0';
341 if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
342 *buf) {
343 buf[sizeof(buf) - 1] = '\0';
344 p = buf;
345 }
346 }
347#endif
348
349
350 if (!p) {
351 if (!argv0) {
352 return;
353 }
354 p = realpath(argv0, buf);
355 if (!p) {
356 return;
357 }
358 }
359 dir = g_path_get_dirname(p);
360
361 pstrcpy(exec_dir, sizeof(exec_dir), dir);
362
363 g_free(dir);
364}
365
366char *qemu_get_exec_dir(void)
367{
368 return g_strdup(exec_dir);
369}
370
371static void sigbus_handler(int signal)
372{
373 int i;
374 if (memset_thread) {
375 for (i = 0; i < memset_num_threads; i++) {
376 if (qemu_thread_is_self(&memset_thread[i].pgthread)) {
377 siglongjmp(memset_thread[i].env, 1);
378 }
379 }
380 }
381}
382
383static void *do_touch_pages(void *arg)
384{
385 MemsetThread *memset_args = (MemsetThread *)arg;
386 sigset_t set, oldset;
387
388
389 sigemptyset(&set);
390 sigaddset(&set, SIGBUS);
391 pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
392
393 if (sigsetjmp(memset_args->env, 1)) {
394 memset_thread_failed = true;
395 } else {
396 char *addr = memset_args->addr;
397 size_t numpages = memset_args->numpages;
398 size_t hpagesize = memset_args->hpagesize;
399 size_t i;
400 for (i = 0; i < numpages; i++) {
401
402
403
404
405
406
407
408
409
410
411
412
413 *(volatile char *)addr = *addr;
414 addr += hpagesize;
415 }
416 }
417 pthread_sigmask(SIG_SETMASK, &oldset, NULL);
418 return NULL;
419}
420
421static inline int get_memset_num_threads(int smp_cpus)
422{
423 long host_procs = sysconf(_SC_NPROCESSORS_ONLN);
424 int ret = 1;
425
426 if (host_procs > 0) {
427 ret = MIN(MIN(host_procs, MAX_MEM_PREALLOC_THREAD_COUNT), smp_cpus);
428 }
429
430 return ret;
431}
432
433static bool touch_all_pages(char *area, size_t hpagesize, size_t numpages,
434 int smp_cpus)
435{
436 size_t numpages_per_thread;
437 size_t size_per_thread;
438 char *addr = area;
439 int i = 0;
440
441 memset_thread_failed = false;
442 memset_num_threads = get_memset_num_threads(smp_cpus);
443 memset_thread = g_new0(MemsetThread, memset_num_threads);
444 numpages_per_thread = (numpages / memset_num_threads);
445 size_per_thread = (hpagesize * numpages_per_thread);
446 for (i = 0; i < memset_num_threads; i++) {
447 memset_thread[i].addr = addr;
448 memset_thread[i].numpages = (i == (memset_num_threads - 1)) ?
449 numpages : numpages_per_thread;
450 memset_thread[i].hpagesize = hpagesize;
451 qemu_thread_create(&memset_thread[i].pgthread, "touch_pages",
452 do_touch_pages, &memset_thread[i],
453 QEMU_THREAD_JOINABLE);
454 addr += size_per_thread;
455 numpages -= numpages_per_thread;
456 }
457 for (i = 0; i < memset_num_threads; i++) {
458 qemu_thread_join(&memset_thread[i].pgthread);
459 }
460 g_free(memset_thread);
461 memset_thread = NULL;
462
463 return memset_thread_failed;
464}
465
466void os_mem_prealloc(int fd, char *area, size_t memory, int smp_cpus,
467 Error **errp)
468{
469 int ret;
470 struct sigaction act, oldact;
471 size_t hpagesize = qemu_fd_getpagesize(fd);
472 size_t numpages = DIV_ROUND_UP(memory, hpagesize);
473
474 memset(&act, 0, sizeof(act));
475 act.sa_handler = &sigbus_handler;
476 act.sa_flags = 0;
477
478 ret = sigaction(SIGBUS, &act, &oldact);
479 if (ret) {
480 error_setg_errno(errp, errno,
481 "os_mem_prealloc: failed to install signal handler");
482 return;
483 }
484
485
486 if (touch_all_pages(area, hpagesize, numpages, smp_cpus)) {
487 error_setg(errp, "os_mem_prealloc: Insufficient free host memory "
488 "pages available to allocate guest RAM");
489 }
490
491 ret = sigaction(SIGBUS, &oldact, NULL);
492 if (ret) {
493
494 perror("os_mem_prealloc: failed to reinstall signal handler");
495 exit(1);
496 }
497}
498
499
500char *qemu_get_pid_name(pid_t pid)
501{
502 char *name = NULL;
503
504#if defined(__FreeBSD__)
505
506 struct kinfo_proc *proc = kinfo_getproc(pid);
507
508 if (proc) {
509 name = g_strdup(proc->ki_comm);
510 free(proc);
511 }
512#else
513
514 char *pid_path;
515 size_t len;
516
517 pid_path = g_strdup_printf("/proc/%d/cmdline", pid);
518 g_file_get_contents(pid_path, &name, &len, NULL);
519 g_free(pid_path);
520#endif
521
522 return name;
523}
524
525
526pid_t qemu_fork(Error **errp)
527{
528 sigset_t oldmask, newmask;
529 struct sigaction sig_action;
530 int saved_errno;
531 pid_t pid;
532
533
534
535
536
537 sigfillset(&newmask);
538 if (pthread_sigmask(SIG_SETMASK, &newmask, &oldmask) != 0) {
539 error_setg_errno(errp, errno,
540 "cannot block signals");
541 return -1;
542 }
543
544 pid = fork();
545 saved_errno = errno;
546
547 if (pid < 0) {
548
549
550 (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
551 error_setg_errno(errp, saved_errno,
552 "cannot fork child process");
553 errno = saved_errno;
554 return -1;
555 } else if (pid) {
556
557
558
559
560
561
562 (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
563 } else {
564
565 size_t i;
566
567
568
569
570 sig_action.sa_handler = SIG_DFL;
571 sig_action.sa_flags = 0;
572 sigemptyset(&sig_action.sa_mask);
573
574 for (i = 1; i < NSIG; i++) {
575
576
577
578 (void)sigaction(i, &sig_action, NULL);
579 }
580
581
582
583
584 sigemptyset(&newmask);
585 if (pthread_sigmask(SIG_SETMASK, &newmask, NULL) != 0) {
586 Error *local_err = NULL;
587 error_setg_errno(&local_err, errno,
588 "cannot unblock signals");
589 error_report_err(local_err);
590 _exit(1);
591 }
592 }
593 return pid;
594}
595
596void *qemu_alloc_stack(size_t *sz)
597{
598 void *ptr, *guardpage;
599 int flags;
600#ifdef CONFIG_DEBUG_STACK_USAGE
601 void *ptr2;
602#endif
603 size_t pagesz = getpagesize();
604#ifdef _SC_THREAD_STACK_MIN
605
606 long min_stack_sz = sysconf(_SC_THREAD_STACK_MIN);
607 *sz = MAX(MAX(min_stack_sz, 0), *sz);
608#endif
609
610 *sz = ROUND_UP(*sz, pagesz);
611
612 *sz += pagesz;
613
614 flags = MAP_PRIVATE | MAP_ANONYMOUS;
615#if defined(MAP_STACK) && defined(__OpenBSD__)
616
617
618
619
620
621
622 flags |= MAP_STACK;
623#endif
624
625 ptr = mmap(NULL, *sz, PROT_READ | PROT_WRITE, flags, -1, 0);
626 if (ptr == MAP_FAILED) {
627 perror("failed to allocate memory for stack");
628 abort();
629 }
630
631#if defined(HOST_IA64)
632
633 guardpage = ptr + (((*sz - pagesz) / 2) & ~pagesz);
634#elif defined(HOST_HPPA)
635
636 guardpage = ptr + *sz - pagesz;
637#else
638
639 guardpage = ptr;
640#endif
641 if (mprotect(guardpage, pagesz, PROT_NONE) != 0) {
642 perror("failed to set up stack guard page");
643 abort();
644 }
645
646#ifdef CONFIG_DEBUG_STACK_USAGE
647 for (ptr2 = ptr + pagesz; ptr2 < ptr + *sz; ptr2 += sizeof(uint32_t)) {
648 *(uint32_t *)ptr2 = 0xdeadbeaf;
649 }
650#endif
651
652 return ptr;
653}
654
655#ifdef CONFIG_DEBUG_STACK_USAGE
656static __thread unsigned int max_stack_usage;
657#endif
658
659void qemu_free_stack(void *stack, size_t sz)
660{
661#ifdef CONFIG_DEBUG_STACK_USAGE
662 unsigned int usage;
663 void *ptr;
664
665 for (ptr = stack + getpagesize(); ptr < stack + sz;
666 ptr += sizeof(uint32_t)) {
667 if (*(uint32_t *)ptr != 0xdeadbeaf) {
668 break;
669 }
670 }
671 usage = sz - (uintptr_t) (ptr - stack);
672 if (usage > max_stack_usage) {
673 error_report("thread %d max stack usage increased from %u to %u",
674 qemu_get_thread_id(), max_stack_usage, usage);
675 max_stack_usage = usage;
676 }
677#endif
678
679 munmap(stack, sz);
680}
681
682void sigaction_invoke(struct sigaction *action,
683 struct qemu_signalfd_siginfo *info)
684{
685 siginfo_t si = {};
686 si.si_signo = info->ssi_signo;
687 si.si_errno = info->ssi_errno;
688 si.si_code = info->ssi_code;
689
690
691
692
693
694
695
696
697 if (info->ssi_code == SI_USER || info->ssi_code == SI_QUEUE ||
698 info->ssi_code <= 0) {
699
700 si.si_pid = info->ssi_pid;
701 si.si_uid = info->ssi_uid;
702 } else if (info->ssi_signo == SIGILL || info->ssi_signo == SIGFPE ||
703 info->ssi_signo == SIGSEGV || info->ssi_signo == SIGBUS) {
704 si.si_addr = (void *)(uintptr_t)info->ssi_addr;
705 } else if (info->ssi_signo == SIGCHLD) {
706 si.si_pid = info->ssi_pid;
707 si.si_status = info->ssi_status;
708 si.si_uid = info->ssi_uid;
709 }
710 action->sa_sigaction(info->ssi_signo, &si, NULL);
711}
712