]>
Commit | Line | Data |
---|---|---|
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 | /* The following block of code temporarily renames the daemon() function so the | |
30 | compiler does not see the warning associated with it in stdlib.h on OSX */ | |
31 | #ifdef __APPLE__ | |
32 | #define daemon qemu_fake_daemon_function | |
33 | #include <stdlib.h> | |
34 | #undef daemon | |
35 | extern int daemon(int, int); | |
36 | #endif | |
37 | ||
38 | #if defined(__linux__) && (defined(__x86_64__) || defined(__arm__)) | |
39 | /* Use 2 MiB alignment so transparent hugepages can be used by KVM. | |
40 | Valgrind does not support alignments larger than 1 MiB, | |
41 | therefore we need special code which handles running on Valgrind. */ | |
42 | # define QEMU_VMALLOC_ALIGN (512 * 4096) | |
43 | #elif defined(__linux__) && defined(__s390x__) | |
44 | /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */ | |
45 | # define QEMU_VMALLOC_ALIGN (256 * 4096) | |
46 | #else | |
47 | # define QEMU_VMALLOC_ALIGN getpagesize() | |
48 | #endif | |
49 | #define HUGETLBFS_MAGIC 0x958458f6 | |
50 | ||
51 | #include <termios.h> | |
52 | #include <unistd.h> | |
53 | ||
54 | #include <glib/gprintf.h> | |
55 | ||
56 | #include "config-host.h" | |
57 | #include "sysemu/sysemu.h" | |
58 | #include "trace.h" | |
59 | #include "qemu/sockets.h" | |
60 | #include <sys/mman.h> | |
61 | #include <libgen.h> | |
62 | #include <setjmp.h> | |
63 | #include <sys/signal.h> | |
64 | ||
65 | #ifdef CONFIG_LINUX | |
66 | #include <sys/syscall.h> | |
67 | #include <sys/vfs.h> | |
68 | #endif | |
69 | ||
70 | #ifdef __FreeBSD__ | |
71 | #include <sys/sysctl.h> | |
72 | #endif | |
73 | ||
74 | int qemu_get_thread_id(void) | |
75 | { | |
76 | #if defined(__linux__) | |
77 | return syscall(SYS_gettid); | |
78 | #else | |
79 | return getpid(); | |
80 | #endif | |
81 | } | |
82 | ||
83 | int qemu_daemon(int nochdir, int noclose) | |
84 | { | |
85 | return daemon(nochdir, noclose); | |
86 | } | |
87 | ||
88 | void *qemu_oom_check(void *ptr) | |
89 | { | |
90 | if (ptr == NULL) { | |
91 | fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno)); | |
92 | abort(); | |
93 | } | |
94 | return ptr; | |
95 | } | |
96 | ||
97 | void *qemu_try_memalign(size_t alignment, size_t size) | |
98 | { | |
99 | void *ptr; | |
100 | ||
101 | if (alignment < sizeof(void*)) { | |
102 | alignment = sizeof(void*); | |
103 | } | |
104 | ||
105 | #if defined(_POSIX_C_SOURCE) && !defined(__sun__) | |
106 | int ret; | |
107 | ret = posix_memalign(&ptr, alignment, size); | |
108 | if (ret != 0) { | |
109 | errno = ret; | |
110 | ptr = NULL; | |
111 | } | |
112 | #elif defined(CONFIG_BSD) | |
113 | ptr = valloc(size); | |
114 | #else | |
115 | ptr = memalign(alignment, size); | |
116 | #endif | |
117 | trace_qemu_memalign(alignment, size, ptr); | |
118 | return ptr; | |
119 | } | |
120 | ||
121 | void *qemu_memalign(size_t alignment, size_t size) | |
122 | { | |
123 | return qemu_oom_check(qemu_try_memalign(alignment, size)); | |
124 | } | |
125 | ||
126 | /* alloc shared memory pages */ | |
127 | void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment) | |
128 | { | |
129 | size_t align = QEMU_VMALLOC_ALIGN; | |
130 | size_t total = size + align - getpagesize(); | |
131 | void *ptr = mmap(0, total, PROT_READ | PROT_WRITE, | |
132 | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); | |
133 | size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr; | |
134 | ||
135 | if (ptr == MAP_FAILED) { | |
136 | return NULL; | |
137 | } | |
138 | ||
139 | if (alignment) { | |
140 | *alignment = align; | |
141 | } | |
142 | ptr += offset; | |
143 | total -= offset; | |
144 | ||
145 | if (offset > 0) { | |
146 | munmap(ptr - offset, offset); | |
147 | } | |
148 | if (total > size) { | |
149 | munmap(ptr + size, total - size); | |
150 | } | |
151 | ||
152 | trace_qemu_anon_ram_alloc(size, ptr); | |
153 | return ptr; | |
154 | } | |
155 | ||
156 | void qemu_vfree(void *ptr) | |
157 | { | |
158 | trace_qemu_vfree(ptr); | |
159 | free(ptr); | |
160 | } | |
161 | ||
162 | void qemu_anon_ram_free(void *ptr, size_t size) | |
163 | { | |
164 | trace_qemu_anon_ram_free(ptr, size); | |
165 | if (ptr) { | |
166 | munmap(ptr, size); | |
167 | } | |
168 | } | |
169 | ||
170 | void qemu_set_block(int fd) | |
171 | { | |
172 | int f; | |
173 | f = fcntl(fd, F_GETFL); | |
174 | fcntl(fd, F_SETFL, f & ~O_NONBLOCK); | |
175 | } | |
176 | ||
177 | void qemu_set_nonblock(int fd) | |
178 | { | |
179 | int f; | |
180 | f = fcntl(fd, F_GETFL); | |
181 | fcntl(fd, F_SETFL, f | O_NONBLOCK); | |
182 | } | |
183 | ||
184 | int socket_set_fast_reuse(int fd) | |
185 | { | |
186 | int val = 1, ret; | |
187 | ||
188 | ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, | |
189 | (const char *)&val, sizeof(val)); | |
190 | ||
191 | assert(ret == 0); | |
192 | ||
193 | return ret; | |
194 | } | |
195 | ||
196 | void qemu_set_cloexec(int fd) | |
197 | { | |
198 | int f; | |
199 | f = fcntl(fd, F_GETFD); | |
200 | fcntl(fd, F_SETFD, f | FD_CLOEXEC); | |
201 | } | |
202 | ||
203 | /* | |
204 | * Creates a pipe with FD_CLOEXEC set on both file descriptors | |
205 | */ | |
206 | int qemu_pipe(int pipefd[2]) | |
207 | { | |
208 | int ret; | |
209 | ||
210 | #ifdef CONFIG_PIPE2 | |
211 | ret = pipe2(pipefd, O_CLOEXEC); | |
212 | if (ret != -1 || errno != ENOSYS) { | |
213 | return ret; | |
214 | } | |
215 | #endif | |
216 | ret = pipe(pipefd); | |
217 | if (ret == 0) { | |
218 | qemu_set_cloexec(pipefd[0]); | |
219 | qemu_set_cloexec(pipefd[1]); | |
220 | } | |
221 | ||
222 | return ret; | |
223 | } | |
224 | ||
225 | int qemu_utimens(const char *path, const struct timespec *times) | |
226 | { | |
227 | struct timeval tv[2], tv_now; | |
228 | struct stat st; | |
229 | int i; | |
230 | #ifdef CONFIG_UTIMENSAT | |
231 | int ret; | |
232 | ||
233 | ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW); | |
234 | if (ret != -1 || errno != ENOSYS) { | |
235 | return ret; | |
236 | } | |
237 | #endif | |
238 | /* Fallback: use utimes() instead of utimensat() */ | |
239 | ||
240 | /* happy if special cases */ | |
241 | if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) { | |
242 | return 0; | |
243 | } | |
244 | if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) { | |
245 | return utimes(path, NULL); | |
246 | } | |
247 | ||
248 | /* prepare for hard cases */ | |
249 | if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) { | |
250 | gettimeofday(&tv_now, NULL); | |
251 | } | |
252 | if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) { | |
253 | stat(path, &st); | |
254 | } | |
255 | ||
256 | for (i = 0; i < 2; i++) { | |
257 | if (times[i].tv_nsec == UTIME_NOW) { | |
258 | tv[i].tv_sec = tv_now.tv_sec; | |
259 | tv[i].tv_usec = tv_now.tv_usec; | |
260 | } else if (times[i].tv_nsec == UTIME_OMIT) { | |
261 | tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime; | |
262 | tv[i].tv_usec = 0; | |
263 | } else { | |
264 | tv[i].tv_sec = times[i].tv_sec; | |
265 | tv[i].tv_usec = times[i].tv_nsec / 1000; | |
266 | } | |
267 | } | |
268 | ||
269 | return utimes(path, &tv[0]); | |
270 | } | |
271 | ||
272 | char * | |
273 | qemu_get_local_state_pathname(const char *relative_pathname) | |
274 | { | |
275 | return g_strdup_printf("%s/%s", CONFIG_QEMU_LOCALSTATEDIR, | |
276 | relative_pathname); | |
277 | } | |
278 | ||
279 | void qemu_set_tty_echo(int fd, bool echo) | |
280 | { | |
281 | struct termios tty; | |
282 | ||
283 | tcgetattr(fd, &tty); | |
284 | ||
285 | if (echo) { | |
286 | tty.c_lflag |= ECHO | ECHONL | ICANON | IEXTEN; | |
287 | } else { | |
288 | tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN); | |
289 | } | |
290 | ||
291 | tcsetattr(fd, TCSANOW, &tty); | |
292 | } | |
293 | ||
294 | static char exec_dir[PATH_MAX]; | |
295 | ||
296 | void qemu_init_exec_dir(const char *argv0) | |
297 | { | |
298 | char *dir; | |
299 | char *p = NULL; | |
300 | char buf[PATH_MAX]; | |
301 | ||
302 | assert(!exec_dir[0]); | |
303 | ||
304 | #if defined(__linux__) | |
305 | { | |
306 | int len; | |
307 | len = readlink("/proc/self/exe", buf, sizeof(buf) - 1); | |
308 | if (len > 0) { | |
309 | buf[len] = 0; | |
310 | p = buf; | |
311 | } | |
312 | } | |
313 | #elif defined(__FreeBSD__) | |
314 | { | |
315 | static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1}; | |
316 | size_t len = sizeof(buf) - 1; | |
317 | ||
318 | *buf = '\0'; | |
319 | if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) && | |
320 | *buf) { | |
321 | buf[sizeof(buf) - 1] = '\0'; | |
322 | p = buf; | |
323 | } | |
324 | } | |
325 | #endif | |
326 | /* If we don't have any way of figuring out the actual executable | |
327 | location then try argv[0]. */ | |
328 | if (!p) { | |
329 | if (!argv0) { | |
330 | return; | |
331 | } | |
332 | p = realpath(argv0, buf); | |
333 | if (!p) { | |
334 | return; | |
335 | } | |
336 | } | |
337 | dir = dirname(p); | |
338 | ||
339 | pstrcpy(exec_dir, sizeof(exec_dir), dir); | |
340 | } | |
341 | ||
342 | char *qemu_get_exec_dir(void) | |
343 | { | |
344 | return g_strdup(exec_dir); | |
345 | } | |
346 | ||
347 | static sigjmp_buf sigjump; | |
348 | ||
349 | static void sigbus_handler(int signal) | |
350 | { | |
351 | siglongjmp(sigjump, 1); | |
352 | } | |
353 | ||
354 | static size_t fd_getpagesize(int fd) | |
355 | { | |
356 | #ifdef CONFIG_LINUX | |
357 | struct statfs fs; | |
358 | int ret; | |
359 | ||
360 | if (fd != -1) { | |
361 | do { | |
362 | ret = fstatfs(fd, &fs); | |
363 | } while (ret != 0 && errno == EINTR); | |
364 | ||
365 | if (ret == 0 && fs.f_type == HUGETLBFS_MAGIC) { | |
366 | return fs.f_bsize; | |
367 | } | |
368 | } | |
369 | #endif | |
370 | ||
371 | return getpagesize(); | |
372 | } | |
373 | ||
374 | void os_mem_prealloc(int fd, char *area, size_t memory) | |
375 | { | |
376 | int ret; | |
377 | struct sigaction act, oldact; | |
378 | sigset_t set, oldset; | |
379 | ||
380 | memset(&act, 0, sizeof(act)); | |
381 | act.sa_handler = &sigbus_handler; | |
382 | act.sa_flags = 0; | |
383 | ||
384 | ret = sigaction(SIGBUS, &act, &oldact); | |
385 | if (ret) { | |
386 | perror("os_mem_prealloc: failed to install signal handler"); | |
387 | exit(1); | |
388 | } | |
389 | ||
390 | /* unblock SIGBUS */ | |
391 | sigemptyset(&set); | |
392 | sigaddset(&set, SIGBUS); | |
393 | pthread_sigmask(SIG_UNBLOCK, &set, &oldset); | |
394 | ||
395 | if (sigsetjmp(sigjump, 1)) { | |
396 | fprintf(stderr, "os_mem_prealloc: Insufficient free host memory " | |
397 | "pages available to allocate guest RAM\n"); | |
398 | exit(1); | |
399 | } else { | |
400 | int i; | |
401 | size_t hpagesize = fd_getpagesize(fd); | |
402 | ||
403 | /* MAP_POPULATE silently ignores failures */ | |
404 | memory = (memory + hpagesize - 1) & -hpagesize; | |
405 | for (i = 0; i < (memory / hpagesize); i++) { | |
406 | memset(area + (hpagesize * i), 0, 1); | |
407 | } | |
408 | ||
409 | ret = sigaction(SIGBUS, &oldact, NULL); | |
410 | if (ret) { | |
411 | perror("os_mem_prealloc: failed to reinstall signal handler"); | |
412 | exit(1); | |
413 | } | |
414 | ||
415 | pthread_sigmask(SIG_SETMASK, &oldset, NULL); | |
416 | } | |
417 | } |