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c1b0b93b JS |
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 | ||
aafd7584 | 29 | #include "qemu/osdep.h" |
13401ba0 | 30 | #include <termios.h> |
13401ba0 | 31 | |
e2ea3515 LE |
32 | #include <glib/gprintf.h> |
33 | ||
9c17d615 | 34 | #include "sysemu/sysemu.h" |
c1b0b93b | 35 | #include "trace.h" |
da34e65c | 36 | #include "qapi/error.h" |
29b838c0 | 37 | #include "qemu/error-report.h" |
b85ea5fa | 38 | #include "qemu/madvise.h" |
1de7afc9 | 39 | #include "qemu/sockets.h" |
db725815 | 40 | #include "qemu/thread.h" |
10f5bff6 | 41 | #include <libgen.h> |
f348b6d1 | 42 | #include "qemu/cutils.h" |
89aec641 | 43 | #include "qemu/units.h" |
e2de2c49 | 44 | #include "qemu/thread-context.h" |
04accf43 | 45 | #include "qemu/main-loop.h" |
c1b0b93b | 46 | |
cbcfa041 PB |
47 | #ifdef CONFIG_LINUX |
48 | #include <sys/syscall.h> | |
49 | #endif | |
cbcfa041 | 50 | |
41975b26 | 51 | #ifdef __FreeBSD__ |
9548a891 | 52 | #include <sys/thr.h> |
06680b15 | 53 | #include <sys/user.h> |
7dc9ae43 | 54 | #include <libutil.h> |
41975b26 AF |
55 | #endif |
56 | ||
094611b4 | 57 | #ifdef __NetBSD__ |
9548a891 | 58 | #include <lwp.h> |
094611b4 KR |
59 | #endif |
60 | ||
a9c94277 | 61 | #include "qemu/mmap-alloc.h" |
794e8f30 | 62 | |
dfd0dcc7 | 63 | #define MAX_MEM_PREALLOC_THREAD_COUNT 16 |
1e356fc1 | 64 | |
dba50678 DH |
65 | struct MemsetThread; |
66 | ||
04accf43 MK |
67 | static QLIST_HEAD(, MemsetContext) memset_contexts = |
68 | QLIST_HEAD_INITIALIZER(memset_contexts); | |
69 | ||
dba50678 DH |
70 | typedef struct MemsetContext { |
71 | bool all_threads_created; | |
72 | bool any_thread_failed; | |
73 | struct MemsetThread *threads; | |
74 | int num_threads; | |
04accf43 | 75 | QLIST_ENTRY(MemsetContext) next; |
dba50678 DH |
76 | } MemsetContext; |
77 | ||
1e356fc1 JK |
78 | struct MemsetThread { |
79 | char *addr; | |
e947d47d SW |
80 | size_t numpages; |
81 | size_t hpagesize; | |
1e356fc1 JK |
82 | QemuThread pgthread; |
83 | sigjmp_buf env; | |
dba50678 | 84 | MemsetContext *context; |
1e356fc1 JK |
85 | }; |
86 | typedef struct MemsetThread MemsetThread; | |
87 | ||
dba50678 DH |
88 | /* used by sigbus_handler() */ |
89 | static MemsetContext *sigbus_memset_context; | |
29b838c0 | 90 | struct sigaction sigbus_oldact; |
a960d664 | 91 | static QemuMutex sigbus_mutex; |
1e356fc1 | 92 | |
037fb5eb | 93 | static QemuMutex page_mutex; |
94 | static QemuCond page_cond; | |
037fb5eb | 95 | |
cbcfa041 PB |
96 | int qemu_get_thread_id(void) |
97 | { | |
98 | #if defined(__linux__) | |
99 | return syscall(SYS_gettid); | |
9548a891 DC |
100 | #elif defined(__FreeBSD__) |
101 | /* thread id is up to INT_MAX */ | |
102 | long tid; | |
103 | thr_self(&tid); | |
104 | return (int)tid; | |
105 | #elif defined(__NetBSD__) | |
106 | return _lwp_self(); | |
8edbca51 DC |
107 | #elif defined(__OpenBSD__) |
108 | return getthrid(); | |
cbcfa041 PB |
109 | #else |
110 | return getpid(); | |
111 | #endif | |
112 | } | |
f97742d0 AR |
113 | |
114 | int qemu_daemon(int nochdir, int noclose) | |
115 | { | |
116 | return daemon(nochdir, noclose); | |
117 | } | |
118 | ||
9e6bdef2 MAL |
119 | bool qemu_write_pidfile(const char *path, Error **errp) |
120 | { | |
121 | int fd; | |
122 | char pidstr[32]; | |
123 | ||
124 | while (1) { | |
125 | struct stat a, b; | |
35f7f3fb MAL |
126 | struct flock lock = { |
127 | .l_type = F_WRLCK, | |
128 | .l_whence = SEEK_SET, | |
129 | .l_len = 0, | |
130 | }; | |
9e6bdef2 | 131 | |
1b34d08f | 132 | fd = qemu_create(path, O_WRONLY, S_IRUSR | S_IWUSR, errp); |
9e6bdef2 | 133 | if (fd == -1) { |
9e6bdef2 MAL |
134 | return false; |
135 | } | |
136 | ||
137 | if (fstat(fd, &b) < 0) { | |
138 | error_setg_errno(errp, errno, "Cannot stat file"); | |
139 | goto fail_close; | |
140 | } | |
141 | ||
35f7f3fb | 142 | if (fcntl(fd, F_SETLK, &lock)) { |
9e6bdef2 MAL |
143 | error_setg_errno(errp, errno, "Cannot lock pid file"); |
144 | goto fail_close; | |
145 | } | |
146 | ||
147 | /* | |
148 | * Now make sure the path we locked is the same one that now | |
149 | * exists on the filesystem. | |
150 | */ | |
151 | if (stat(path, &a) < 0) { | |
152 | /* | |
153 | * PID file disappeared, someone else must be racing with | |
154 | * us, so try again. | |
155 | */ | |
156 | close(fd); | |
157 | continue; | |
158 | } | |
159 | ||
160 | if (a.st_ino == b.st_ino) { | |
161 | break; | |
162 | } | |
163 | ||
164 | /* | |
165 | * PID file was recreated, someone else must be racing with | |
166 | * us, so try again. | |
167 | */ | |
168 | close(fd); | |
169 | } | |
170 | ||
171 | if (ftruncate(fd, 0) < 0) { | |
172 | error_setg_errno(errp, errno, "Failed to truncate pid file"); | |
173 | goto fail_unlink; | |
174 | } | |
175 | ||
176 | snprintf(pidstr, sizeof(pidstr), FMT_pid "\n", getpid()); | |
96eb9b2b | 177 | if (qemu_write_full(fd, pidstr, strlen(pidstr)) != strlen(pidstr)) { |
9e6bdef2 MAL |
178 | error_setg(errp, "Failed to write pid file"); |
179 | goto fail_unlink; | |
180 | } | |
181 | ||
182 | return true; | |
183 | ||
184 | fail_unlink: | |
185 | unlink(path); | |
186 | fail_close: | |
187 | close(fd); | |
188 | return false; | |
189 | } | |
190 | ||
c1b0b93b | 191 | /* alloc shared memory pages */ |
8dbe22c6 DH |
192 | void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared, |
193 | bool noreserve) | |
c1b0b93b | 194 | { |
8dbe22c6 DH |
195 | const uint32_t qemu_map_flags = (shared ? QEMU_MAP_SHARED : 0) | |
196 | (noreserve ? QEMU_MAP_NORESERVE : 0); | |
36b58628 | 197 | size_t align = QEMU_VMALLOC_ALIGN; |
b444f5c0 | 198 | void *ptr = qemu_ram_mmap(-1, size, align, qemu_map_flags, 0); |
36b58628 | 199 | |
7dda5dc8 | 200 | if (ptr == MAP_FAILED) { |
39228250 | 201 | return NULL; |
c2a8238a | 202 | } |
c2a8238a | 203 | |
a2b257d6 IM |
204 | if (alignment) { |
205 | *alignment = align; | |
206 | } | |
c2dfc5ba | 207 | |
6eebf958 | 208 | trace_qemu_anon_ram_alloc(size, ptr); |
c7f4111a | 209 | return ptr; |
c1b0b93b JS |
210 | } |
211 | ||
e7a09b92 PB |
212 | void qemu_anon_ram_free(void *ptr, size_t size) |
213 | { | |
214 | trace_qemu_anon_ram_free(ptr, size); | |
53adb9d4 | 215 | qemu_ram_munmap(-1, ptr, size); |
e7a09b92 PB |
216 | } |
217 | ||
ff5927ba | 218 | void qemu_socket_set_block(int fd) |
154b9a0c | 219 | { |
22e135fc | 220 | g_unix_set_fd_nonblocking(fd, false, NULL); |
154b9a0c PB |
221 | } |
222 | ||
ff5927ba | 223 | int qemu_socket_try_set_nonblock(int fd) |
9549e764 | 224 | { |
22e135fc | 225 | return g_unix_set_fd_nonblocking(fd, true, NULL) ? 0 : -errno; |
894022e6 LV |
226 | } |
227 | ||
ff5927ba | 228 | void qemu_socket_set_nonblock(int fd) |
894022e6 LV |
229 | { |
230 | int f; | |
ff5927ba | 231 | f = qemu_socket_try_set_nonblock(fd); |
894022e6 | 232 | assert(f == 0); |
9549e764 JS |
233 | } |
234 | ||
606600a1 SO |
235 | int socket_set_fast_reuse(int fd) |
236 | { | |
237 | int val = 1, ret; | |
238 | ||
239 | ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, | |
240 | (const char *)&val, sizeof(val)); | |
241 | ||
242 | assert(ret == 0); | |
243 | ||
244 | return ret; | |
245 | } | |
246 | ||
9549e764 JS |
247 | void qemu_set_cloexec(int fd) |
248 | { | |
249 | int f; | |
250 | f = fcntl(fd, F_GETFD); | |
7e6478e7 SS |
251 | assert(f != -1); |
252 | f = fcntl(fd, F_SETFD, f | FD_CLOEXEC); | |
253 | assert(f != -1); | |
9549e764 | 254 | } |
70e72ce4 | 255 | |
3c63b4e9 GT |
256 | int qemu_socketpair(int domain, int type, int protocol, int sv[2]) |
257 | { | |
258 | int ret; | |
259 | ||
260 | #ifdef SOCK_CLOEXEC | |
261 | ret = socketpair(domain, type | SOCK_CLOEXEC, protocol, sv); | |
262 | if (ret != -1 || errno != EINVAL) { | |
263 | return ret; | |
264 | } | |
265 | #endif | |
083c4e71 | 266 | ret = socketpair(domain, type, protocol, sv); |
3c63b4e9 GT |
267 | if (ret == 0) { |
268 | qemu_set_cloexec(sv[0]); | |
269 | qemu_set_cloexec(sv[1]); | |
270 | } | |
271 | ||
272 | return ret; | |
273 | } | |
274 | ||
e2ea3515 | 275 | char * |
1fbf2665 | 276 | qemu_get_local_state_dir(void) |
e2ea3515 | 277 | { |
1fbf2665 | 278 | return get_relocated_path(CONFIG_QEMU_LOCALSTATEDIR); |
e2ea3515 | 279 | } |
13401ba0 SH |
280 | |
281 | void qemu_set_tty_echo(int fd, bool echo) | |
282 | { | |
283 | struct termios tty; | |
284 | ||
285 | tcgetattr(fd, &tty); | |
286 | ||
287 | if (echo) { | |
288 | tty.c_lflag |= ECHO | ECHONL | ICANON | IEXTEN; | |
289 | } else { | |
290 | tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN); | |
291 | } | |
292 | ||
293 | tcsetattr(fd, TCSANOW, &tty); | |
294 | } | |
10f5bff6 | 295 | |
29b838c0 DH |
296 | #ifdef CONFIG_LINUX |
297 | static void sigbus_handler(int signal, siginfo_t *siginfo, void *ctx) | |
298 | #else /* CONFIG_LINUX */ | |
38183310 | 299 | static void sigbus_handler(int signal) |
29b838c0 | 300 | #endif /* CONFIG_LINUX */ |
38183310 | 301 | { |
1e356fc1 | 302 | int i; |
dba50678 DH |
303 | |
304 | if (sigbus_memset_context) { | |
305 | for (i = 0; i < sigbus_memset_context->num_threads; i++) { | |
306 | MemsetThread *thread = &sigbus_memset_context->threads[i]; | |
307 | ||
308 | if (qemu_thread_is_self(&thread->pgthread)) { | |
309 | siglongjmp(thread->env, 1); | |
1e356fc1 JK |
310 | } |
311 | } | |
312 | } | |
29b838c0 DH |
313 | |
314 | #ifdef CONFIG_LINUX | |
315 | /* | |
316 | * We assume that the MCE SIGBUS handler could have been registered. We | |
317 | * should never receive BUS_MCEERR_AO on any of our threads, but only on | |
318 | * the main thread registered for PR_MCE_KILL_EARLY. Further, we should not | |
319 | * receive BUS_MCEERR_AR triggered by action of other threads on one of | |
320 | * our threads. So, no need to check for unrelated SIGBUS when seeing one | |
321 | * for our threads. | |
322 | * | |
323 | * We will forward to the MCE handler, which will either handle the SIGBUS | |
324 | * or reinstall the default SIGBUS handler and reraise the SIGBUS. The | |
325 | * default SIGBUS handler will crash the process, so we don't care. | |
326 | */ | |
327 | if (sigbus_oldact.sa_flags & SA_SIGINFO) { | |
328 | sigbus_oldact.sa_sigaction(signal, siginfo, ctx); | |
329 | return; | |
330 | } | |
331 | #endif /* CONFIG_LINUX */ | |
6556aadc | 332 | warn_report("qemu_prealloc_mem: unrelated SIGBUS detected and ignored"); |
38183310 PB |
333 | } |
334 | ||
1e356fc1 JK |
335 | static void *do_touch_pages(void *arg) |
336 | { | |
337 | MemsetThread *memset_args = (MemsetThread *)arg; | |
1e356fc1 | 338 | sigset_t set, oldset; |
6c427ab9 | 339 | int ret = 0; |
1e356fc1 | 340 | |
037fb5eb | 341 | /* |
342 | * On Linux, the page faults from the loop below can cause mmap_sem | |
343 | * contention with allocation of the thread stacks. Do not start | |
344 | * clearing until all threads have been created. | |
345 | */ | |
346 | qemu_mutex_lock(&page_mutex); | |
dba50678 | 347 | while (!memset_args->context->all_threads_created) { |
037fb5eb | 348 | qemu_cond_wait(&page_cond, &page_mutex); |
349 | } | |
350 | qemu_mutex_unlock(&page_mutex); | |
351 | ||
1e356fc1 JK |
352 | /* unblock SIGBUS */ |
353 | sigemptyset(&set); | |
354 | sigaddset(&set, SIGBUS); | |
355 | pthread_sigmask(SIG_UNBLOCK, &set, &oldset); | |
356 | ||
357 | if (sigsetjmp(memset_args->env, 1)) { | |
6c427ab9 | 358 | ret = -EFAULT; |
1e356fc1 | 359 | } else { |
e947d47d SW |
360 | char *addr = memset_args->addr; |
361 | size_t numpages = memset_args->numpages; | |
362 | size_t hpagesize = memset_args->hpagesize; | |
363 | size_t i; | |
1e356fc1 | 364 | for (i = 0; i < numpages; i++) { |
9dc44aa5 DB |
365 | /* |
366 | * Read & write back the same value, so we don't | |
367 | * corrupt existing user/app data that might be | |
368 | * stored. | |
369 | * | |
370 | * 'volatile' to stop compiler optimizing this away | |
371 | * to a no-op | |
9dc44aa5 DB |
372 | */ |
373 | *(volatile char *)addr = *addr; | |
1e356fc1 JK |
374 | addr += hpagesize; |
375 | } | |
376 | } | |
377 | pthread_sigmask(SIG_SETMASK, &oldset, NULL); | |
6c427ab9 | 378 | return (void *)(uintptr_t)ret; |
1e356fc1 JK |
379 | } |
380 | ||
a384bfa3 DH |
381 | static void *do_madv_populate_write_pages(void *arg) |
382 | { | |
383 | MemsetThread *memset_args = (MemsetThread *)arg; | |
384 | const size_t size = memset_args->numpages * memset_args->hpagesize; | |
385 | char * const addr = memset_args->addr; | |
386 | int ret = 0; | |
387 | ||
388 | /* See do_touch_pages(). */ | |
389 | qemu_mutex_lock(&page_mutex); | |
dba50678 | 390 | while (!memset_args->context->all_threads_created) { |
a384bfa3 DH |
391 | qemu_cond_wait(&page_cond, &page_mutex); |
392 | } | |
393 | qemu_mutex_unlock(&page_mutex); | |
394 | ||
395 | if (size && qemu_madvise(addr, size, QEMU_MADV_POPULATE_WRITE)) { | |
396 | ret = -errno; | |
397 | } | |
398 | return (void *)(uintptr_t)ret; | |
399 | } | |
400 | ||
89aec641 | 401 | static inline int get_memset_num_threads(size_t hpagesize, size_t numpages, |
6556aadc | 402 | int max_threads) |
dfd0dcc7 JK |
403 | { |
404 | long host_procs = sysconf(_SC_NPROCESSORS_ONLN); | |
405 | int ret = 1; | |
406 | ||
407 | if (host_procs > 0) { | |
6556aadc | 408 | ret = MIN(MIN(host_procs, MAX_MEM_PREALLOC_THREAD_COUNT), max_threads); |
dfd0dcc7 | 409 | } |
89aec641 DH |
410 | |
411 | /* Especially with gigantic pages, don't create more threads than pages. */ | |
412 | ret = MIN(ret, numpages); | |
413 | /* Don't start threads to prealloc comparatively little memory. */ | |
414 | ret = MIN(ret, MAX(1, hpagesize * numpages / (64 * MiB))); | |
415 | ||
dfd0dcc7 JK |
416 | /* In case sysconf() fails, we fall back to single threaded */ |
417 | return ret; | |
418 | } | |
419 | ||
04accf43 MK |
420 | static int wait_and_free_mem_prealloc_context(MemsetContext *context) |
421 | { | |
422 | int i, ret = 0, tmp; | |
423 | ||
424 | for (i = 0; i < context->num_threads; i++) { | |
425 | tmp = (uintptr_t)qemu_thread_join(&context->threads[i].pgthread); | |
426 | ||
427 | if (tmp) { | |
428 | ret = tmp; | |
429 | } | |
430 | } | |
431 | g_free(context->threads); | |
432 | g_free(context); | |
433 | return ret; | |
434 | } | |
435 | ||
6c427ab9 | 436 | static int touch_all_pages(char *area, size_t hpagesize, size_t numpages, |
04accf43 | 437 | int max_threads, ThreadContext *tc, bool async, |
e04a34e5 | 438 | bool use_madv_populate_write) |
1e356fc1 | 439 | { |
78b3f67a | 440 | static gsize initialized = 0; |
04accf43 | 441 | MemsetContext *context = g_malloc0(sizeof(MemsetContext)); |
037fb5eb | 442 | size_t numpages_per_thread, leftover; |
a384bfa3 | 443 | void *(*touch_fn)(void *); |
04accf43 | 444 | int ret, i = 0; |
1e356fc1 | 445 | char *addr = area; |
1e356fc1 | 446 | |
04accf43 MK |
447 | /* |
448 | * Asynchronous preallocation is only allowed when using MADV_POPULATE_WRITE | |
449 | * and prealloc context for thread placement. | |
450 | */ | |
451 | if (!use_madv_populate_write || !tc) { | |
452 | async = false; | |
453 | } | |
454 | ||
455 | context->num_threads = | |
456 | get_memset_num_threads(hpagesize, numpages, max_threads); | |
457 | ||
78b3f67a PB |
458 | if (g_once_init_enter(&initialized)) { |
459 | qemu_mutex_init(&page_mutex); | |
460 | qemu_cond_init(&page_cond); | |
461 | g_once_init_leave(&initialized, 1); | |
462 | } | |
463 | ||
a384bfa3 | 464 | if (use_madv_populate_write) { |
04accf43 MK |
465 | /* |
466 | * Avoid creating a single thread for MADV_POPULATE_WRITE when | |
467 | * preallocating synchronously. | |
468 | */ | |
469 | if (context->num_threads == 1 && !async) { | |
44a90c08 | 470 | ret = 0; |
ac86e5c3 DH |
471 | if (qemu_madvise(area, hpagesize * numpages, |
472 | QEMU_MADV_POPULATE_WRITE)) { | |
44a90c08 | 473 | ret = -errno; |
ac86e5c3 | 474 | } |
44a90c08 PB |
475 | g_free(context); |
476 | return ret; | |
ac86e5c3 | 477 | } |
a384bfa3 DH |
478 | touch_fn = do_madv_populate_write_pages; |
479 | } else { | |
480 | touch_fn = do_touch_pages; | |
481 | } | |
482 | ||
04accf43 MK |
483 | context->threads = g_new0(MemsetThread, context->num_threads); |
484 | numpages_per_thread = numpages / context->num_threads; | |
485 | leftover = numpages % context->num_threads; | |
486 | for (i = 0; i < context->num_threads; i++) { | |
487 | context->threads[i].addr = addr; | |
488 | context->threads[i].numpages = numpages_per_thread + (i < leftover); | |
489 | context->threads[i].hpagesize = hpagesize; | |
490 | context->threads[i].context = context; | |
e04a34e5 | 491 | if (tc) { |
04accf43 | 492 | thread_context_create_thread(tc, &context->threads[i].pgthread, |
e04a34e5 | 493 | "touch_pages", |
04accf43 | 494 | touch_fn, &context->threads[i], |
e04a34e5 DH |
495 | QEMU_THREAD_JOINABLE); |
496 | } else { | |
04accf43 MK |
497 | qemu_thread_create(&context->threads[i].pgthread, "touch_pages", |
498 | touch_fn, &context->threads[i], | |
e04a34e5 DH |
499 | QEMU_THREAD_JOINABLE); |
500 | } | |
04accf43 MK |
501 | addr += context->threads[i].numpages * hpagesize; |
502 | } | |
503 | ||
504 | if (async) { | |
505 | /* | |
506 | * async requests currently require the BQL. Add it to the list and kick | |
507 | * preallocation off during qemu_finish_async_prealloc_mem(). | |
508 | */ | |
509 | assert(bql_locked()); | |
510 | QLIST_INSERT_HEAD(&memset_contexts, context, next); | |
511 | return 0; | |
dba50678 DH |
512 | } |
513 | ||
514 | if (!use_madv_populate_write) { | |
04accf43 | 515 | sigbus_memset_context = context; |
1e356fc1 | 516 | } |
278fb162 B |
517 | |
518 | qemu_mutex_lock(&page_mutex); | |
04accf43 | 519 | context->all_threads_created = true; |
037fb5eb | 520 | qemu_cond_broadcast(&page_cond); |
278fb162 | 521 | qemu_mutex_unlock(&page_mutex); |
037fb5eb | 522 | |
04accf43 | 523 | ret = wait_and_free_mem_prealloc_context(context); |
6c427ab9 | 524 | |
04accf43 MK |
525 | if (!use_madv_populate_write) { |
526 | sigbus_memset_context = NULL; | |
527 | } | |
528 | return ret; | |
529 | } | |
530 | ||
531 | bool qemu_finish_async_prealloc_mem(Error **errp) | |
532 | { | |
533 | int ret = 0, tmp; | |
534 | MemsetContext *context, *next_context; | |
535 | ||
536 | /* Waiting for preallocation requires the BQL. */ | |
537 | assert(bql_locked()); | |
538 | if (QLIST_EMPTY(&memset_contexts)) { | |
539 | return true; | |
540 | } | |
541 | ||
542 | qemu_mutex_lock(&page_mutex); | |
543 | QLIST_FOREACH(context, &memset_contexts, next) { | |
544 | context->all_threads_created = true; | |
545 | } | |
546 | qemu_cond_broadcast(&page_cond); | |
547 | qemu_mutex_unlock(&page_mutex); | |
548 | ||
549 | QLIST_FOREACH_SAFE(context, &memset_contexts, next, next_context) { | |
550 | QLIST_REMOVE(context, next); | |
551 | tmp = wait_and_free_mem_prealloc_context(context); | |
6c427ab9 DH |
552 | if (tmp) { |
553 | ret = tmp; | |
554 | } | |
1e356fc1 | 555 | } |
dba50678 | 556 | |
04accf43 MK |
557 | if (ret) { |
558 | error_setg_errno(errp, -ret, | |
559 | "qemu_prealloc_mem: preallocating memory failed"); | |
560 | return false; | |
dba50678 | 561 | } |
04accf43 | 562 | return true; |
1e356fc1 JK |
563 | } |
564 | ||
a384bfa3 DH |
565 | static bool madv_populate_write_possible(char *area, size_t pagesize) |
566 | { | |
567 | return !qemu_madvise(area, pagesize, QEMU_MADV_POPULATE_WRITE) || | |
568 | errno != EINVAL; | |
569 | } | |
570 | ||
b622ee98 | 571 | bool qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads, |
04accf43 | 572 | ThreadContext *tc, bool async, Error **errp) |
38183310 | 573 | { |
a960d664 | 574 | static gsize initialized; |
b7bf8f56 | 575 | int ret; |
1e356fc1 | 576 | size_t hpagesize = qemu_fd_getpagesize(fd); |
6556aadc | 577 | size_t numpages = DIV_ROUND_UP(sz, hpagesize); |
a384bfa3 | 578 | bool use_madv_populate_write; |
29b838c0 | 579 | struct sigaction act; |
b622ee98 | 580 | bool rv = true; |
38183310 | 581 | |
a384bfa3 DH |
582 | /* |
583 | * Sense on every invocation, as MADV_POPULATE_WRITE cannot be used for | |
584 | * some special mappings, such as mapping /dev/mem. | |
585 | */ | |
586 | use_madv_populate_write = madv_populate_write_possible(area, hpagesize); | |
587 | ||
588 | if (!use_madv_populate_write) { | |
a960d664 DH |
589 | if (g_once_init_enter(&initialized)) { |
590 | qemu_mutex_init(&sigbus_mutex); | |
591 | g_once_init_leave(&initialized, 1); | |
592 | } | |
593 | ||
594 | qemu_mutex_lock(&sigbus_mutex); | |
a384bfa3 | 595 | memset(&act, 0, sizeof(act)); |
29b838c0 DH |
596 | #ifdef CONFIG_LINUX |
597 | act.sa_sigaction = &sigbus_handler; | |
598 | act.sa_flags = SA_SIGINFO; | |
599 | #else /* CONFIG_LINUX */ | |
a384bfa3 DH |
600 | act.sa_handler = &sigbus_handler; |
601 | act.sa_flags = 0; | |
29b838c0 | 602 | #endif /* CONFIG_LINUX */ |
a384bfa3 | 603 | |
29b838c0 | 604 | ret = sigaction(SIGBUS, &act, &sigbus_oldact); |
a384bfa3 | 605 | if (ret) { |
dd4fc605 | 606 | qemu_mutex_unlock(&sigbus_mutex); |
a384bfa3 | 607 | error_setg_errno(errp, errno, |
6556aadc | 608 | "qemu_prealloc_mem: failed to install signal handler"); |
b622ee98 | 609 | return false; |
a384bfa3 | 610 | } |
38183310 PB |
611 | } |
612 | ||
1e356fc1 | 613 | /* touch pages simultaneously */ |
04accf43 | 614 | ret = touch_all_pages(area, hpagesize, numpages, max_threads, tc, async, |
a384bfa3 | 615 | use_madv_populate_write); |
6c427ab9 DH |
616 | if (ret) { |
617 | error_setg_errno(errp, -ret, | |
6556aadc | 618 | "qemu_prealloc_mem: preallocating memory failed"); |
b622ee98 | 619 | rv = false; |
056b68af | 620 | } |
38183310 | 621 | |
a384bfa3 | 622 | if (!use_madv_populate_write) { |
29b838c0 | 623 | ret = sigaction(SIGBUS, &sigbus_oldact, NULL); |
a384bfa3 DH |
624 | if (ret) { |
625 | /* Terminate QEMU since it can't recover from error */ | |
6556aadc | 626 | perror("qemu_prealloc_mem: failed to reinstall signal handler"); |
a384bfa3 DH |
627 | exit(1); |
628 | } | |
a960d664 | 629 | qemu_mutex_unlock(&sigbus_mutex); |
b7bf8f56 | 630 | } |
b622ee98 | 631 | return rv; |
38183310 | 632 | } |
d57e4e48 | 633 | |
7dc9ae43 MP |
634 | char *qemu_get_pid_name(pid_t pid) |
635 | { | |
636 | char *name = NULL; | |
637 | ||
638 | #if defined(__FreeBSD__) | |
639 | /* BSDs don't have /proc, but they provide a nice substitute */ | |
640 | struct kinfo_proc *proc = kinfo_getproc(pid); | |
641 | ||
642 | if (proc) { | |
643 | name = g_strdup(proc->ki_comm); | |
644 | free(proc); | |
645 | } | |
646 | #else | |
647 | /* Assume a system with reasonable procfs */ | |
648 | char *pid_path; | |
649 | size_t len; | |
650 | ||
651 | pid_path = g_strdup_printf("/proc/%d/cmdline", pid); | |
652 | g_file_get_contents(pid_path, &name, &len, NULL); | |
653 | g_free(pid_path); | |
654 | #endif | |
655 | ||
656 | return name; | |
657 | } | |
658 | ||
659 | ||
8737d9e0 PL |
660 | void *qemu_alloc_stack(size_t *sz) |
661 | { | |
a1eaa628 | 662 | void *ptr; |
fc3d1bad | 663 | int flags; |
7d992e4d PL |
664 | #ifdef CONFIG_DEBUG_STACK_USAGE |
665 | void *ptr2; | |
666 | #endif | |
8e3b0cbb | 667 | size_t pagesz = qemu_real_host_page_size(); |
8737d9e0 PL |
668 | #ifdef _SC_THREAD_STACK_MIN |
669 | /* avoid stacks smaller than _SC_THREAD_STACK_MIN */ | |
670 | long min_stack_sz = sysconf(_SC_THREAD_STACK_MIN); | |
671 | *sz = MAX(MAX(min_stack_sz, 0), *sz); | |
672 | #endif | |
673 | /* adjust stack size to a multiple of the page size */ | |
674 | *sz = ROUND_UP(*sz, pagesz); | |
675 | /* allocate one extra page for the guard page */ | |
676 | *sz += pagesz; | |
677 | ||
fc3d1bad BS |
678 | flags = MAP_PRIVATE | MAP_ANONYMOUS; |
679 | #if defined(MAP_STACK) && defined(__OpenBSD__) | |
680 | /* Only enable MAP_STACK on OpenBSD. Other OS's such as | |
681 | * Linux/FreeBSD/NetBSD have a flag with the same name | |
682 | * but have differing functionality. OpenBSD will SEGV | |
683 | * if it spots execution with a stack pointer pointing | |
684 | * at memory that was not allocated with MAP_STACK. | |
685 | */ | |
686 | flags |= MAP_STACK; | |
687 | #endif | |
688 | ||
689 | ptr = mmap(NULL, *sz, PROT_READ | PROT_WRITE, flags, -1, 0); | |
8737d9e0 | 690 | if (ptr == MAP_FAILED) { |
e916a6e8 | 691 | perror("failed to allocate memory for stack"); |
8737d9e0 PL |
692 | abort(); |
693 | } | |
694 | ||
a1eaa628 AO |
695 | /* Stack grows down -- guard page at the bottom. */ |
696 | if (mprotect(ptr, pagesz, PROT_NONE) != 0) { | |
e916a6e8 | 697 | perror("failed to set up stack guard page"); |
8737d9e0 PL |
698 | abort(); |
699 | } | |
700 | ||
7d992e4d PL |
701 | #ifdef CONFIG_DEBUG_STACK_USAGE |
702 | for (ptr2 = ptr + pagesz; ptr2 < ptr + *sz; ptr2 += sizeof(uint32_t)) { | |
703 | *(uint32_t *)ptr2 = 0xdeadbeaf; | |
704 | } | |
705 | #endif | |
706 | ||
8737d9e0 PL |
707 | return ptr; |
708 | } | |
709 | ||
7d992e4d PL |
710 | #ifdef CONFIG_DEBUG_STACK_USAGE |
711 | static __thread unsigned int max_stack_usage; | |
712 | #endif | |
713 | ||
8737d9e0 PL |
714 | void qemu_free_stack(void *stack, size_t sz) |
715 | { | |
7d992e4d PL |
716 | #ifdef CONFIG_DEBUG_STACK_USAGE |
717 | unsigned int usage; | |
718 | void *ptr; | |
719 | ||
8e3b0cbb | 720 | for (ptr = stack + qemu_real_host_page_size(); ptr < stack + sz; |
7d992e4d PL |
721 | ptr += sizeof(uint32_t)) { |
722 | if (*(uint32_t *)ptr != 0xdeadbeaf) { | |
723 | break; | |
724 | } | |
725 | } | |
726 | usage = sz - (uintptr_t) (ptr - stack); | |
727 | if (usage > max_stack_usage) { | |
728 | error_report("thread %d max stack usage increased from %u to %u", | |
729 | qemu_get_thread_id(), max_stack_usage, usage); | |
730 | max_stack_usage = usage; | |
731 | } | |
732 | #endif | |
733 | ||
8737d9e0 PL |
734 | munmap(stack, sz); |
735 | } | |
d98d4072 | 736 | |
c905a368 DB |
737 | /* |
738 | * Disable CFI checks. | |
d02d06f8 | 739 | * We are going to call a signal handler directly. Such handler may or may not |
c905a368 DB |
740 | * have been defined in our binary, so there's no guarantee that the pointer |
741 | * used to set the handler is a cfi-valid pointer. Since the handlers are | |
742 | * stored in kernel memory, changing the handler to an attacker-defined | |
743 | * function requires being able to call a sigaction() syscall, | |
744 | * which is not as easy as overwriting a pointer in memory. | |
745 | */ | |
746 | QEMU_DISABLE_CFI | |
d98d4072 PB |
747 | void sigaction_invoke(struct sigaction *action, |
748 | struct qemu_signalfd_siginfo *info) | |
749 | { | |
02ffa034 | 750 | siginfo_t si = {}; |
d98d4072 PB |
751 | si.si_signo = info->ssi_signo; |
752 | si.si_errno = info->ssi_errno; | |
753 | si.si_code = info->ssi_code; | |
754 | ||
755 | /* Convert the minimal set of fields defined by POSIX. | |
756 | * Positive si_code values are reserved for kernel-generated | |
757 | * signals, where the valid siginfo fields are determined by | |
758 | * the signal number. But according to POSIX, it is unspecified | |
759 | * whether SI_USER and SI_QUEUE have values less than or equal to | |
760 | * zero. | |
761 | */ | |
762 | if (info->ssi_code == SI_USER || info->ssi_code == SI_QUEUE || | |
763 | info->ssi_code <= 0) { | |
764 | /* SIGTERM, etc. */ | |
765 | si.si_pid = info->ssi_pid; | |
766 | si.si_uid = info->ssi_uid; | |
767 | } else if (info->ssi_signo == SIGILL || info->ssi_signo == SIGFPE || | |
768 | info->ssi_signo == SIGSEGV || info->ssi_signo == SIGBUS) { | |
769 | si.si_addr = (void *)(uintptr_t)info->ssi_addr; | |
770 | } else if (info->ssi_signo == SIGCHLD) { | |
771 | si.si_pid = info->ssi_pid; | |
772 | si.si_status = info->ssi_status; | |
773 | si.si_uid = info->ssi_uid; | |
d98d4072 PB |
774 | } |
775 | action->sa_sigaction(info->ssi_signo, &si, NULL); | |
776 | } | |
e47f4765 | 777 | |
ad06ef0e AB |
778 | size_t qemu_get_host_physmem(void) |
779 | { | |
780 | #ifdef _SC_PHYS_PAGES | |
781 | long pages = sysconf(_SC_PHYS_PAGES); | |
782 | if (pages > 0) { | |
8e3b0cbb | 783 | if (pages > SIZE_MAX / qemu_real_host_page_size()) { |
ad06ef0e AB |
784 | return SIZE_MAX; |
785 | } else { | |
8e3b0cbb | 786 | return pages * qemu_real_host_page_size(); |
ad06ef0e AB |
787 | } |
788 | } | |
789 | #endif | |
790 | return 0; | |
791 | } | |
e9c4e0a8 | 792 | |
73991a92 MAL |
793 | int qemu_msync(void *addr, size_t length, int fd) |
794 | { | |
795 | size_t align_mask = ~(qemu_real_host_page_size() - 1); | |
796 | ||
797 | /** | |
798 | * There are no strict reqs as per the length of mapping | |
799 | * to be synced. Still the length needs to follow the address | |
800 | * alignment changes. Additionally - round the size to the multiple | |
801 | * of PAGE_SIZE | |
802 | */ | |
803 | length += ((uintptr_t)addr & (qemu_real_host_page_size() - 1)); | |
804 | length = (length + ~align_mask) & align_mask; | |
805 | ||
806 | addr = (void *)((uintptr_t)addr & align_mask); | |
807 | ||
808 | return msync(addr, length, MS_SYNC); | |
809 | } | |
4ec5ebea | 810 | |
7532ca57 | 811 | static bool qemu_close_all_open_fd_proc(const int *skip, unsigned int nskip) |
4ec5ebea CL |
812 | { |
813 | struct dirent *de; | |
814 | int fd, dfd; | |
815 | DIR *dir; | |
7532ca57 | 816 | unsigned int skip_start = 0, skip_end = nskip; |
4ec5ebea | 817 | |
4ec5ebea CL |
818 | dir = opendir("/proc/self/fd"); |
819 | if (!dir) { | |
820 | /* If /proc is not mounted, there is nothing that can be done. */ | |
ffa28f9c | 821 | return false; |
4ec5ebea CL |
822 | } |
823 | /* Avoid closing the directory. */ | |
824 | dfd = dirfd(dir); | |
825 | ||
826 | for (de = readdir(dir); de; de = readdir(dir)) { | |
7532ca57 CL |
827 | bool close_fd = true; |
828 | ||
829 | if (de->d_name[0] == '.') { | |
830 | continue; | |
831 | } | |
4ec5ebea | 832 | fd = atoi(de->d_name); |
7532ca57 CL |
833 | if (fd == dfd) { |
834 | continue; | |
835 | } | |
836 | ||
837 | for (unsigned int i = skip_start; i < skip_end; i++) { | |
838 | if (fd < skip[i]) { | |
839 | /* We are below the next skipped fd, break */ | |
840 | break; | |
841 | } else if (fd == skip[i]) { | |
842 | close_fd = false; | |
843 | /* Restrict the range as we found fds matching start/end */ | |
844 | if (i == skip_start) { | |
845 | skip_start++; | |
846 | } else if (i == skip_end) { | |
847 | skip_end--; | |
848 | } | |
849 | break; | |
850 | } | |
851 | } | |
852 | ||
853 | if (close_fd) { | |
4ec5ebea CL |
854 | close(fd); |
855 | } | |
856 | } | |
857 | closedir(dir); | |
ffa28f9c CL |
858 | |
859 | return true; | |
860 | } | |
861 | ||
7532ca57 CL |
862 | static bool qemu_close_all_open_fd_close_range(const int *skip, |
863 | unsigned int nskip, | |
864 | int open_max) | |
ffa28f9c CL |
865 | { |
866 | #ifdef CONFIG_CLOSE_RANGE | |
7532ca57 CL |
867 | int max_fd = open_max - 1; |
868 | int first = 0, last; | |
869 | unsigned int cur_skip = 0; | |
870 | int ret; | |
871 | ||
872 | do { | |
873 | /* Find the start boundary of the range to close */ | |
874 | while (cur_skip < nskip && first == skip[cur_skip]) { | |
875 | cur_skip++; | |
876 | first++; | |
877 | } | |
878 | ||
879 | /* Find the upper boundary of the range to close */ | |
880 | last = max_fd; | |
881 | if (cur_skip < nskip) { | |
882 | last = skip[cur_skip] - 1; | |
883 | last = MIN(last, max_fd); | |
884 | } | |
885 | ||
886 | /* With the adjustments to the range, we might be done. */ | |
887 | if (first > last) { | |
888 | break; | |
889 | } | |
890 | ||
891 | ret = close_range(first, last, 0); | |
892 | if (ret < 0) { | |
893 | return false; | |
894 | } | |
895 | ||
896 | first = last + 1; | |
897 | } while (last < max_fd); | |
898 | ||
899 | return true; | |
900 | #else | |
ffa28f9c | 901 | return false; |
7532ca57 | 902 | #endif |
ffa28f9c CL |
903 | } |
904 | ||
7532ca57 CL |
905 | static void qemu_close_all_open_fd_fallback(const int *skip, unsigned int nskip, |
906 | int open_max) | |
ffa28f9c | 907 | { |
7532ca57 | 908 | unsigned int cur_skip = 0; |
ffa28f9c CL |
909 | |
910 | /* Fallback */ | |
7532ca57 CL |
911 | for (int i = 0; i < open_max; i++) { |
912 | if (cur_skip < nskip && i == skip[cur_skip]) { | |
913 | cur_skip++; | |
914 | continue; | |
915 | } | |
ffa28f9c CL |
916 | close(i); |
917 | } | |
918 | } | |
919 | ||
920 | /* | |
921 | * Close all open file descriptors. | |
922 | */ | |
7532ca57 | 923 | void qemu_close_all_open_fd(const int *skip, unsigned int nskip) |
ffa28f9c | 924 | { |
7532ca57 CL |
925 | int open_max = sysconf(_SC_OPEN_MAX); |
926 | ||
927 | assert(skip != NULL || nskip == 0); | |
928 | ||
929 | if (!qemu_close_all_open_fd_close_range(skip, nskip, open_max) && | |
930 | !qemu_close_all_open_fd_proc(skip, nskip)) { | |
931 | qemu_close_all_open_fd_fallback(skip, nskip, open_max); | |
ffa28f9c | 932 | } |
4ec5ebea | 933 | } |