mips: Ensure PC update with MTC0 single-stepping
[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 /* 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)
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 ptr += offset;
140 total -= offset;
141
142 if (offset > 0) {
143 munmap(ptr - offset, offset);
144 }
145 if (total > size) {
146 munmap(ptr + size, total - size);
147 }
148
149 trace_qemu_anon_ram_alloc(size, ptr);
150 return ptr;
151 }
152
153 void qemu_vfree(void *ptr)
154 {
155 trace_qemu_vfree(ptr);
156 free(ptr);
157 }
158
159 void qemu_anon_ram_free(void *ptr, size_t size)
160 {
161 trace_qemu_anon_ram_free(ptr, size);
162 if (ptr) {
163 munmap(ptr, size);
164 }
165 }
166
167 void qemu_set_block(int fd)
168 {
169 int f;
170 f = fcntl(fd, F_GETFL);
171 fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
172 }
173
174 void qemu_set_nonblock(int fd)
175 {
176 int f;
177 f = fcntl(fd, F_GETFL);
178 fcntl(fd, F_SETFL, f | O_NONBLOCK);
179 }
180
181 int socket_set_fast_reuse(int fd)
182 {
183 int val = 1, ret;
184
185 ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
186 (const char *)&val, sizeof(val));
187
188 assert(ret == 0);
189
190 return ret;
191 }
192
193 void qemu_set_cloexec(int fd)
194 {
195 int f;
196 f = fcntl(fd, F_GETFD);
197 fcntl(fd, F_SETFD, f | FD_CLOEXEC);
198 }
199
200 /*
201 * Creates a pipe with FD_CLOEXEC set on both file descriptors
202 */
203 int qemu_pipe(int pipefd[2])
204 {
205 int ret;
206
207 #ifdef CONFIG_PIPE2
208 ret = pipe2(pipefd, O_CLOEXEC);
209 if (ret != -1 || errno != ENOSYS) {
210 return ret;
211 }
212 #endif
213 ret = pipe(pipefd);
214 if (ret == 0) {
215 qemu_set_cloexec(pipefd[0]);
216 qemu_set_cloexec(pipefd[1]);
217 }
218
219 return ret;
220 }
221
222 int qemu_utimens(const char *path, const struct timespec *times)
223 {
224 struct timeval tv[2], tv_now;
225 struct stat st;
226 int i;
227 #ifdef CONFIG_UTIMENSAT
228 int ret;
229
230 ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW);
231 if (ret != -1 || errno != ENOSYS) {
232 return ret;
233 }
234 #endif
235 /* Fallback: use utimes() instead of utimensat() */
236
237 /* happy if special cases */
238 if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) {
239 return 0;
240 }
241 if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) {
242 return utimes(path, NULL);
243 }
244
245 /* prepare for hard cases */
246 if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) {
247 gettimeofday(&tv_now, NULL);
248 }
249 if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) {
250 stat(path, &st);
251 }
252
253 for (i = 0; i < 2; i++) {
254 if (times[i].tv_nsec == UTIME_NOW) {
255 tv[i].tv_sec = tv_now.tv_sec;
256 tv[i].tv_usec = tv_now.tv_usec;
257 } else if (times[i].tv_nsec == UTIME_OMIT) {
258 tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;
259 tv[i].tv_usec = 0;
260 } else {
261 tv[i].tv_sec = times[i].tv_sec;
262 tv[i].tv_usec = times[i].tv_nsec / 1000;
263 }
264 }
265
266 return utimes(path, &tv[0]);
267 }
268
269 char *
270 qemu_get_local_state_pathname(const char *relative_pathname)
271 {
272 return g_strdup_printf("%s/%s", CONFIG_QEMU_LOCALSTATEDIR,
273 relative_pathname);
274 }
275
276 void qemu_set_tty_echo(int fd, bool echo)
277 {
278 struct termios tty;
279
280 tcgetattr(fd, &tty);
281
282 if (echo) {
283 tty.c_lflag |= ECHO | ECHONL | ICANON | IEXTEN;
284 } else {
285 tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);
286 }
287
288 tcsetattr(fd, TCSANOW, &tty);
289 }
290
291 static char exec_dir[PATH_MAX];
292
293 void qemu_init_exec_dir(const char *argv0)
294 {
295 char *dir;
296 char *p = NULL;
297 char buf[PATH_MAX];
298
299 assert(!exec_dir[0]);
300
301 #if defined(__linux__)
302 {
303 int len;
304 len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
305 if (len > 0) {
306 buf[len] = 0;
307 p = buf;
308 }
309 }
310 #elif defined(__FreeBSD__)
311 {
312 static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
313 size_t len = sizeof(buf) - 1;
314
315 *buf = '\0';
316 if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
317 *buf) {
318 buf[sizeof(buf) - 1] = '\0';
319 p = buf;
320 }
321 }
322 #endif
323 /* If we don't have any way of figuring out the actual executable
324 location then try argv[0]. */
325 if (!p) {
326 if (!argv0) {
327 return;
328 }
329 p = realpath(argv0, buf);
330 if (!p) {
331 return;
332 }
333 }
334 dir = dirname(p);
335
336 pstrcpy(exec_dir, sizeof(exec_dir), dir);
337 }
338
339 char *qemu_get_exec_dir(void)
340 {
341 return g_strdup(exec_dir);
342 }
343
344 static sigjmp_buf sigjump;
345
346 static void sigbus_handler(int signal)
347 {
348 siglongjmp(sigjump, 1);
349 }
350
351 static size_t fd_getpagesize(int fd)
352 {
353 #ifdef CONFIG_LINUX
354 struct statfs fs;
355 int ret;
356
357 if (fd != -1) {
358 do {
359 ret = fstatfs(fd, &fs);
360 } while (ret != 0 && errno == EINTR);
361
362 if (ret == 0 && fs.f_type == HUGETLBFS_MAGIC) {
363 return fs.f_bsize;
364 }
365 }
366 #endif
367
368 return getpagesize();
369 }
370
371 void os_mem_prealloc(int fd, char *area, size_t memory)
372 {
373 int ret;
374 struct sigaction act, oldact;
375 sigset_t set, oldset;
376
377 memset(&act, 0, sizeof(act));
378 act.sa_handler = &sigbus_handler;
379 act.sa_flags = 0;
380
381 ret = sigaction(SIGBUS, &act, &oldact);
382 if (ret) {
383 perror("os_mem_prealloc: failed to install signal handler");
384 exit(1);
385 }
386
387 /* unblock SIGBUS */
388 sigemptyset(&set);
389 sigaddset(&set, SIGBUS);
390 pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
391
392 if (sigsetjmp(sigjump, 1)) {
393 fprintf(stderr, "os_mem_prealloc: Insufficient free host memory "
394 "pages available to allocate guest RAM\n");
395 exit(1);
396 } else {
397 int i;
398 size_t hpagesize = fd_getpagesize(fd);
399
400 /* MAP_POPULATE silently ignores failures */
401 memory = (memory + hpagesize - 1) & -hpagesize;
402 for (i = 0; i < (memory / hpagesize); i++) {
403 memset(area + (hpagesize * i), 0, 1);
404 }
405
406 ret = sigaction(SIGBUS, &oldact, NULL);
407 if (ret) {
408 perror("os_mem_prealloc: failed to reinstall signal handler");
409 exit(1);
410 }
411
412 pthread_sigmask(SIG_SETMASK, &oldset, NULL);
413 }
414 }