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28
29#include "qemu/osdep.h"
30#include <termios.h>
31
32#include <glib/gprintf.h>
33
34#include "qemu-common.h"
35#include "sysemu/sysemu.h"
36#include "trace.h"
37#include "qapi/error.h"
38#include "qemu/sockets.h"
39#include "qemu/thread.h"
40#include <libgen.h>
41#include "qemu/cutils.h"
42
43#ifdef CONFIG_LINUX
44#include <sys/syscall.h>
45#endif
46
47#ifdef __FreeBSD__
48#include <sys/sysctl.h>
49#include <sys/user.h>
50#include <sys/thr.h>
51#include <libutil.h>
52#endif
53
54#ifdef __NetBSD__
55#include <sys/sysctl.h>
56#include <lwp.h>
57#endif
58
59#ifdef __APPLE__
60#include <mach-o/dyld.h>
61#endif
62
63#ifdef __HAIKU__
64#include <kernel/image.h>
65#endif
66
67#include "qemu/mmap-alloc.h"
68
69#ifdef CONFIG_DEBUG_STACK_USAGE
70#include "qemu/error-report.h"
71#endif
72
73#define MAX_MEM_PREALLOC_THREAD_COUNT 16
74
75struct MemsetThread {
76 char *addr;
77 size_t numpages;
78 size_t hpagesize;
79 QemuThread pgthread;
80 sigjmp_buf env;
81};
82typedef struct MemsetThread MemsetThread;
83
84static MemsetThread *memset_thread;
85static int memset_num_threads;
86static bool memset_thread_failed;
87
88static QemuMutex page_mutex;
89static QemuCond page_cond;
90static bool threads_created_flag;
91
92int qemu_get_thread_id(void)
93{
94#if defined(__linux__)
95 return syscall(SYS_gettid);
96#elif defined(__FreeBSD__)
97
98 long tid;
99 thr_self(&tid);
100 return (int)tid;
101#elif defined(__NetBSD__)
102 return _lwp_self();
103#elif defined(__OpenBSD__)
104 return getthrid();
105#else
106 return getpid();
107#endif
108}
109
110int qemu_daemon(int nochdir, int noclose)
111{
112 return daemon(nochdir, noclose);
113}
114
115bool qemu_write_pidfile(const char *path, Error **errp)
116{
117 int fd;
118 char pidstr[32];
119
120 while (1) {
121 struct stat a, b;
122 struct flock lock = {
123 .l_type = F_WRLCK,
124 .l_whence = SEEK_SET,
125 .l_len = 0,
126 };
127
128 fd = qemu_open(path, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR);
129 if (fd == -1) {
130 error_setg_errno(errp, errno, "Cannot open pid file");
131 return false;
132 }
133
134 if (fstat(fd, &b) < 0) {
135 error_setg_errno(errp, errno, "Cannot stat file");
136 goto fail_close;
137 }
138
139 if (fcntl(fd, F_SETLK, &lock)) {
140 error_setg_errno(errp, errno, "Cannot lock pid file");
141 goto fail_close;
142 }
143
144
145
146
147
148 if (stat(path, &a) < 0) {
149
150
151
152
153 close(fd);
154 continue;
155 }
156
157 if (a.st_ino == b.st_ino) {
158 break;
159 }
160
161
162
163
164
165 close(fd);
166 }
167
168 if (ftruncate(fd, 0) < 0) {
169 error_setg_errno(errp, errno, "Failed to truncate pid file");
170 goto fail_unlink;
171 }
172
173 snprintf(pidstr, sizeof(pidstr), FMT_pid "\n", getpid());
174 if (write(fd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
175 error_setg(errp, "Failed to write pid file");
176 goto fail_unlink;
177 }
178
179 return true;
180
181fail_unlink:
182 unlink(path);
183fail_close:
184 close(fd);
185 return false;
186}
187
188void *qemu_oom_check(void *ptr)
189{
190 if (ptr == NULL) {
191 fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
192 abort();
193 }
194 return ptr;
195}
196
197void *qemu_try_memalign(size_t alignment, size_t size)
198{
199 void *ptr;
200
201 if (alignment < sizeof(void*)) {
202 alignment = sizeof(void*);
203 }
204
205#if defined(CONFIG_POSIX_MEMALIGN)
206 int ret;
207 ret = posix_memalign(&ptr, alignment, size);
208 if (ret != 0) {
209 errno = ret;
210 ptr = NULL;
211 }
212#elif defined(CONFIG_BSD)
213 ptr = valloc(size);
214#else
215 ptr = memalign(alignment, size);
216#endif
217 trace_qemu_memalign(alignment, size, ptr);
218 return ptr;
219}
220
221void *qemu_memalign(size_t alignment, size_t size)
222{
223 return qemu_oom_check(qemu_try_memalign(alignment, size));
224}
225
226
227void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared)
228{
229 size_t align = QEMU_VMALLOC_ALIGN;
230 void *ptr = qemu_ram_mmap(-1, size, align, shared, false);
231
232 if (ptr == MAP_FAILED) {
233 return NULL;
234 }
235
236 if (alignment) {
237 *alignment = align;
238 }
239
240 trace_qemu_anon_ram_alloc(size, ptr);
241 return ptr;
242}
243
244void qemu_vfree(void *ptr)
245{
246 trace_qemu_vfree(ptr);
247 free(ptr);
248}
249
250void qemu_anon_ram_free(void *ptr, size_t size)
251{
252 trace_qemu_anon_ram_free(ptr, size);
253 qemu_ram_munmap(-1, ptr, size);
254}
255
256void qemu_set_block(int fd)
257{
258 int f;
259 f = fcntl(fd, F_GETFL);
260 assert(f != -1);
261 f = fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
262 assert(f != -1);
263}
264
265int qemu_try_set_nonblock(int fd)
266{
267 int f;
268 f = fcntl(fd, F_GETFL);
269 if (f == -1) {
270 return -errno;
271 }
272 if (fcntl(fd, F_SETFL, f | O_NONBLOCK) == -1) {
273#ifdef __OpenBSD__
274
275
276
277
278
279
280 if (errno == ENODEV) {
281 return 0;
282 }
283#endif
284 return -errno;
285 }
286 return 0;
287}
288
289void qemu_set_nonblock(int fd)
290{
291 int f;
292 f = qemu_try_set_nonblock(fd);
293 assert(f == 0);
294}
295
296int socket_set_fast_reuse(int fd)
297{
298 int val = 1, ret;
299
300 ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
301 (const char *)&val, sizeof(val));
302
303 assert(ret == 0);
304
305 return ret;
306}
307
308void qemu_set_cloexec(int fd)
309{
310 int f;
311 f = fcntl(fd, F_GETFD);
312 assert(f != -1);
313 f = fcntl(fd, F_SETFD, f | FD_CLOEXEC);
314 assert(f != -1);
315}
316
317
318
319
320int qemu_pipe(int pipefd[2])
321{
322 int ret;
323
324#ifdef CONFIG_PIPE2
325 ret = pipe2(pipefd, O_CLOEXEC);
326 if (ret != -1 || errno != ENOSYS) {
327 return ret;
328 }
329#endif
330 ret = pipe(pipefd);
331 if (ret == 0) {
332 qemu_set_cloexec(pipefd[0]);
333 qemu_set_cloexec(pipefd[1]);
334 }
335
336 return ret;
337}
338
339char *
340qemu_get_local_state_pathname(const char *relative_pathname)
341{
342 return g_strdup_printf("%s/%s", CONFIG_QEMU_LOCALSTATEDIR,
343 relative_pathname);
344}
345
346void qemu_set_tty_echo(int fd, bool echo)
347{
348 struct termios tty;
349
350 tcgetattr(fd, &tty);
351
352 if (echo) {
353 tty.c_lflag |= ECHO | ECHONL | ICANON | IEXTEN;
354 } else {
355 tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);
356 }
357
358 tcsetattr(fd, TCSANOW, &tty);
359}
360
361static char exec_dir[PATH_MAX];
362
363void qemu_init_exec_dir(const char *argv0)
364{
365 char *dir;
366 char *p = NULL;
367 char buf[PATH_MAX];
368
369 assert(!exec_dir[0]);
370
371#if defined(__linux__)
372 {
373 int len;
374 len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
375 if (len > 0) {
376 buf[len] = 0;
377 p = buf;
378 }
379 }
380#elif defined(__FreeBSD__) \
381 || (defined(__NetBSD__) && defined(KERN_PROC_PATHNAME))
382 {
383#if defined(__FreeBSD__)
384 static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
385#else
386 static int mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
387#endif
388 size_t len = sizeof(buf) - 1;
389
390 *buf = '\0';
391 if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
392 *buf) {
393 buf[sizeof(buf) - 1] = '\0';
394 p = buf;
395 }
396 }
397#elif defined(__APPLE__)
398 {
399 char fpath[PATH_MAX];
400 uint32_t len = sizeof(fpath);
401 if (_NSGetExecutablePath(fpath, &len) == 0) {
402 p = realpath(fpath, buf);
403 if (!p) {
404 return;
405 }
406 }
407 }
408#elif defined(__HAIKU__)
409 {
410 image_info ii;
411 int32_t c = 0;
412
413 *buf = '\0';
414 while (get_next_image_info(0, &c, &ii) == B_OK) {
415 if (ii.type == B_APP_IMAGE) {
416 strncpy(buf, ii.name, sizeof(buf));
417 buf[sizeof(buf) - 1] = 0;
418 p = buf;
419 break;
420 }
421 }
422 }
423#endif
424
425
426 if (!p) {
427 if (!argv0) {
428 return;
429 }
430 p = realpath(argv0, buf);
431 if (!p) {
432 return;
433 }
434 }
435 dir = g_path_get_dirname(p);
436
437 pstrcpy(exec_dir, sizeof(exec_dir), dir);
438
439 g_free(dir);
440}
441
442char *qemu_get_exec_dir(void)
443{
444 return g_strdup(exec_dir);
445}
446
447static void sigbus_handler(int signal)
448{
449 int i;
450 if (memset_thread) {
451 for (i = 0; i < memset_num_threads; i++) {
452 if (qemu_thread_is_self(&memset_thread[i].pgthread)) {
453 siglongjmp(memset_thread[i].env, 1);
454 }
455 }
456 }
457}
458
459static void *do_touch_pages(void *arg)
460{
461 MemsetThread *memset_args = (MemsetThread *)arg;
462 sigset_t set, oldset;
463
464
465
466
467
468
469 qemu_mutex_lock(&page_mutex);
470 while(!threads_created_flag){
471 qemu_cond_wait(&page_cond, &page_mutex);
472 }
473 qemu_mutex_unlock(&page_mutex);
474
475
476 sigemptyset(&set);
477 sigaddset(&set, SIGBUS);
478 pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
479
480 if (sigsetjmp(memset_args->env, 1)) {
481 memset_thread_failed = true;
482 } else {
483 char *addr = memset_args->addr;
484 size_t numpages = memset_args->numpages;
485 size_t hpagesize = memset_args->hpagesize;
486 size_t i;
487 for (i = 0; i < numpages; i++) {
488
489
490
491
492
493
494
495
496
497
498
499
500 *(volatile char *)addr = *addr;
501 addr += hpagesize;
502 }
503 }
504 pthread_sigmask(SIG_SETMASK, &oldset, NULL);
505 return NULL;
506}
507
508static inline int get_memset_num_threads(int smp_cpus)
509{
510 long host_procs = sysconf(_SC_NPROCESSORS_ONLN);
511 int ret = 1;
512
513 if (host_procs > 0) {
514 ret = MIN(MIN(host_procs, MAX_MEM_PREALLOC_THREAD_COUNT), smp_cpus);
515 }
516
517 return ret;
518}
519
520static bool touch_all_pages(char *area, size_t hpagesize, size_t numpages,
521 int smp_cpus)
522{
523 static gsize initialized = 0;
524 size_t numpages_per_thread, leftover;
525 char *addr = area;
526 int i = 0;
527
528 if (g_once_init_enter(&initialized)) {
529 qemu_mutex_init(&page_mutex);
530 qemu_cond_init(&page_cond);
531 g_once_init_leave(&initialized, 1);
532 }
533
534 memset_thread_failed = false;
535 threads_created_flag = false;
536 memset_num_threads = get_memset_num_threads(smp_cpus);
537 memset_thread = g_new0(MemsetThread, memset_num_threads);
538 numpages_per_thread = numpages / memset_num_threads;
539 leftover = numpages % memset_num_threads;
540 for (i = 0; i < memset_num_threads; i++) {
541 memset_thread[i].addr = addr;
542 memset_thread[i].numpages = numpages_per_thread + (i < leftover);
543 memset_thread[i].hpagesize = hpagesize;
544 qemu_thread_create(&memset_thread[i].pgthread, "touch_pages",
545 do_touch_pages, &memset_thread[i],
546 QEMU_THREAD_JOINABLE);
547 addr += memset_thread[i].numpages * hpagesize;
548 }
549
550 qemu_mutex_lock(&page_mutex);
551 threads_created_flag = true;
552 qemu_cond_broadcast(&page_cond);
553 qemu_mutex_unlock(&page_mutex);
554
555 for (i = 0; i < memset_num_threads; i++) {
556 qemu_thread_join(&memset_thread[i].pgthread);
557 }
558 g_free(memset_thread);
559 memset_thread = NULL;
560
561 return memset_thread_failed;
562}
563
564void os_mem_prealloc(int fd, char *area, size_t memory, int smp_cpus,
565 Error **errp)
566{
567 int ret;
568 struct sigaction act, oldact;
569 size_t hpagesize = qemu_fd_getpagesize(fd);
570 size_t numpages = DIV_ROUND_UP(memory, hpagesize);
571
572 memset(&act, 0, sizeof(act));
573 act.sa_handler = &sigbus_handler;
574 act.sa_flags = 0;
575
576 ret = sigaction(SIGBUS, &act, &oldact);
577 if (ret) {
578 error_setg_errno(errp, errno,
579 "os_mem_prealloc: failed to install signal handler");
580 return;
581 }
582
583
584 if (touch_all_pages(area, hpagesize, numpages, smp_cpus)) {
585 error_setg(errp, "os_mem_prealloc: Insufficient free host memory "
586 "pages available to allocate guest RAM");
587 }
588
589 ret = sigaction(SIGBUS, &oldact, NULL);
590 if (ret) {
591
592 perror("os_mem_prealloc: failed to reinstall signal handler");
593 exit(1);
594 }
595}
596
597char *qemu_get_pid_name(pid_t pid)
598{
599 char *name = NULL;
600
601#if defined(__FreeBSD__)
602
603 struct kinfo_proc *proc = kinfo_getproc(pid);
604
605 if (proc) {
606 name = g_strdup(proc->ki_comm);
607 free(proc);
608 }
609#else
610
611 char *pid_path;
612 size_t len;
613
614 pid_path = g_strdup_printf("/proc/%d/cmdline", pid);
615 g_file_get_contents(pid_path, &name, &len, NULL);
616 g_free(pid_path);
617#endif
618
619 return name;
620}
621
622
623pid_t qemu_fork(Error **errp)
624{
625 sigset_t oldmask, newmask;
626 struct sigaction sig_action;
627 int saved_errno;
628 pid_t pid;
629
630
631
632
633
634 sigfillset(&newmask);
635 if (pthread_sigmask(SIG_SETMASK, &newmask, &oldmask) != 0) {
636 error_setg_errno(errp, errno,
637 "cannot block signals");
638 return -1;
639 }
640
641 pid = fork();
642 saved_errno = errno;
643
644 if (pid < 0) {
645
646
647 (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
648 error_setg_errno(errp, saved_errno,
649 "cannot fork child process");
650 errno = saved_errno;
651 return -1;
652 } else if (pid) {
653
654
655
656
657
658
659 (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
660 } else {
661
662 size_t i;
663
664
665
666
667 sig_action.sa_handler = SIG_DFL;
668 sig_action.sa_flags = 0;
669 sigemptyset(&sig_action.sa_mask);
670
671 for (i = 1; i < NSIG; i++) {
672
673
674
675 (void)sigaction(i, &sig_action, NULL);
676 }
677
678
679
680
681 sigemptyset(&newmask);
682 if (pthread_sigmask(SIG_SETMASK, &newmask, NULL) != 0) {
683 Error *local_err = NULL;
684 error_setg_errno(&local_err, errno,
685 "cannot unblock signals");
686 error_report_err(local_err);
687 _exit(1);
688 }
689 }
690 return pid;
691}
692
693void *qemu_alloc_stack(size_t *sz)
694{
695 void *ptr, *guardpage;
696 int flags;
697#ifdef CONFIG_DEBUG_STACK_USAGE
698 void *ptr2;
699#endif
700 size_t pagesz = qemu_real_host_page_size;
701#ifdef _SC_THREAD_STACK_MIN
702
703 long min_stack_sz = sysconf(_SC_THREAD_STACK_MIN);
704 *sz = MAX(MAX(min_stack_sz, 0), *sz);
705#endif
706
707 *sz = ROUND_UP(*sz, pagesz);
708
709 *sz += pagesz;
710
711 flags = MAP_PRIVATE | MAP_ANONYMOUS;
712#if defined(MAP_STACK) && defined(__OpenBSD__)
713
714
715
716
717
718
719 flags |= MAP_STACK;
720#endif
721
722 ptr = mmap(NULL, *sz, PROT_READ | PROT_WRITE, flags, -1, 0);
723 if (ptr == MAP_FAILED) {
724 perror("failed to allocate memory for stack");
725 abort();
726 }
727
728#if defined(HOST_IA64)
729
730 guardpage = ptr + (((*sz - pagesz) / 2) & ~pagesz);
731#elif defined(HOST_HPPA)
732
733 guardpage = ptr + *sz - pagesz;
734#else
735
736 guardpage = ptr;
737#endif
738 if (mprotect(guardpage, pagesz, PROT_NONE) != 0) {
739 perror("failed to set up stack guard page");
740 abort();
741 }
742
743#ifdef CONFIG_DEBUG_STACK_USAGE
744 for (ptr2 = ptr + pagesz; ptr2 < ptr + *sz; ptr2 += sizeof(uint32_t)) {
745 *(uint32_t *)ptr2 = 0xdeadbeaf;
746 }
747#endif
748
749 return ptr;
750}
751
752#ifdef CONFIG_DEBUG_STACK_USAGE
753static __thread unsigned int max_stack_usage;
754#endif
755
756void qemu_free_stack(void *stack, size_t sz)
757{
758#ifdef CONFIG_DEBUG_STACK_USAGE
759 unsigned int usage;
760 void *ptr;
761
762 for (ptr = stack + qemu_real_host_page_size; ptr < stack + sz;
763 ptr += sizeof(uint32_t)) {
764 if (*(uint32_t *)ptr != 0xdeadbeaf) {
765 break;
766 }
767 }
768 usage = sz - (uintptr_t) (ptr - stack);
769 if (usage > max_stack_usage) {
770 error_report("thread %d max stack usage increased from %u to %u",
771 qemu_get_thread_id(), max_stack_usage, usage);
772 max_stack_usage = usage;
773 }
774#endif
775
776 munmap(stack, sz);
777}
778
779void sigaction_invoke(struct sigaction *action,
780 struct qemu_signalfd_siginfo *info)
781{
782 siginfo_t si = {};
783 si.si_signo = info->ssi_signo;
784 si.si_errno = info->ssi_errno;
785 si.si_code = info->ssi_code;
786
787
788
789
790
791
792
793
794 if (info->ssi_code == SI_USER || info->ssi_code == SI_QUEUE ||
795 info->ssi_code <= 0) {
796
797 si.si_pid = info->ssi_pid;
798 si.si_uid = info->ssi_uid;
799 } else if (info->ssi_signo == SIGILL || info->ssi_signo == SIGFPE ||
800 info->ssi_signo == SIGSEGV || info->ssi_signo == SIGBUS) {
801 si.si_addr = (void *)(uintptr_t)info->ssi_addr;
802 } else if (info->ssi_signo == SIGCHLD) {
803 si.si_pid = info->ssi_pid;
804 si.si_status = info->ssi_status;
805 si.si_uid = info->ssi_uid;
806 }
807 action->sa_sigaction(info->ssi_signo, &si, NULL);
808}
809
810#ifndef HOST_NAME_MAX
811# ifdef _POSIX_HOST_NAME_MAX
812# define HOST_NAME_MAX _POSIX_HOST_NAME_MAX
813# else
814# define HOST_NAME_MAX 255
815# endif
816#endif
817
818char *qemu_get_host_name(Error **errp)
819{
820 long len = -1;
821 g_autofree char *hostname = NULL;
822
823#ifdef _SC_HOST_NAME_MAX
824 len = sysconf(_SC_HOST_NAME_MAX);
825#endif
826
827 if (len < 0) {
828 len = HOST_NAME_MAX;
829 }
830
831
832
833
834 hostname = g_new0(char, len + 1);
835
836 if (gethostname(hostname, len) < 0) {
837 error_setg_errno(errp, errno,
838 "cannot get hostname");
839 return NULL;
840 }
841
842 return g_steal_pointer(&hostname);
843}
844
845size_t qemu_get_host_physmem(void)
846{
847#ifdef _SC_PHYS_PAGES
848 long pages = sysconf(_SC_PHYS_PAGES);
849 if (pages > 0) {
850 if (pages > SIZE_MAX / qemu_real_host_page_size) {
851 return SIZE_MAX;
852 } else {
853 return pages * qemu_real_host_page_size;
854 }
855 }
856#endif
857 return 0;
858}
859