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
50 #include "config-host.h"
51 #ifndef CONFIG_ANDROID
52 #include <glib/gprintf.h>
53 #endif
54
55 #include "config-host.h"
56 #include "sysemu/sysemu.h"
57 #include "trace.h"
58 #include "qemu/sockets.h"
59 #include <sys/mman.h>
60
61 #ifdef CONFIG_LINUX
62 #include <sys/syscall.h>
63 #endif
64
qemu_get_thread_id(void)65 int qemu_get_thread_id(void)
66 {
67 #if defined(__linux__)
68 return syscall(SYS_gettid);
69 #else
70 return getpid();
71 #endif
72 }
73
qemu_daemon(int nochdir,int noclose)74 int qemu_daemon(int nochdir, int noclose)
75 {
76 return daemon(nochdir, noclose);
77 }
78
qemu_oom_check(void * ptr)79 void *qemu_oom_check(void *ptr)
80 {
81 if (ptr == NULL) {
82 fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
83 abort();
84 }
85 return ptr;
86 }
87
qemu_memalign(size_t alignment,size_t size)88 void *qemu_memalign(size_t alignment, size_t size)
89 {
90 void *ptr;
91 #if defined(_POSIX_C_SOURCE) && !defined(__sun__)
92 int ret;
93 ret = posix_memalign(&ptr, alignment, size);
94 if (ret != 0) {
95 fprintf(stderr, "Failed to allocate %zu B: %s\n",
96 size, strerror(ret));
97 abort();
98 }
99 #elif defined(CONFIG_BSD)
100 ptr = qemu_oom_check(valloc(size));
101 #else
102 ptr = qemu_oom_check(memalign(alignment, size));
103 #endif
104 //trace_qemu_memalign(alignment, size, ptr);
105 return ptr;
106 }
107
108 /* alloc shared memory pages */
qemu_vmalloc(size_t size)109 void *qemu_vmalloc(size_t size)
110 {
111 return qemu_memalign(getpagesize(), size);
112 }
113
114 /* alloc shared memory pages */
qemu_anon_ram_alloc(size_t size)115 void *qemu_anon_ram_alloc(size_t size)
116 {
117 size_t align = QEMU_VMALLOC_ALIGN;
118 size_t total = size + align - getpagesize();
119 void *ptr = mmap(0, total, PROT_READ | PROT_WRITE,
120 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
121 size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
122
123 if (ptr == MAP_FAILED) {
124 return NULL;
125 }
126
127 ptr += offset;
128 total -= offset;
129
130 if (offset > 0) {
131 munmap(ptr - offset, offset);
132 }
133 if (total > size) {
134 munmap(ptr + size, total - size);
135 }
136
137 //trace_qemu_anon_ram_alloc(size, ptr);
138 return ptr;
139 }
140
qemu_vfree(void * ptr)141 void qemu_vfree(void *ptr)
142 {
143 //trace_qemu_vfree(ptr);
144 free(ptr);
145 }
146
qemu_anon_ram_free(void * ptr,size_t size)147 void qemu_anon_ram_free(void *ptr, size_t size)
148 {
149 //trace_qemu_anon_ram_free(ptr, size);
150 if (ptr) {
151 munmap(ptr, size);
152 }
153 }
154
qemu_set_block(int fd)155 void qemu_set_block(int fd)
156 {
157 int f;
158 f = fcntl(fd, F_GETFL);
159 fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
160 }
161
qemu_set_nonblock(int fd)162 void qemu_set_nonblock(int fd)
163 {
164 int f;
165 f = fcntl(fd, F_GETFL);
166 fcntl(fd, F_SETFL, f | O_NONBLOCK);
167 }
168
socket_set_fast_reuse(int fd)169 int socket_set_fast_reuse(int fd)
170 {
171 #ifdef CONFIG_ANDROID
172 return socket_set_xreuseaddr(fd);
173 #else
174 int val = 1, ret;
175
176 ret = qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
177 (const char *)&val, sizeof(val));
178
179 assert(ret == 0);
180
181 return ret;
182 #endif
183 }
184
qemu_set_cloexec(int fd)185 void qemu_set_cloexec(int fd)
186 {
187 int f;
188 f = fcntl(fd, F_GETFD);
189 fcntl(fd, F_SETFD, f | FD_CLOEXEC);
190 }
191
192 /*
193 * Creates a pipe with FD_CLOEXEC set on both file descriptors
194 */
qemu_pipe(int pipefd[2])195 int qemu_pipe(int pipefd[2])
196 {
197 int ret;
198
199 #ifdef CONFIG_PIPE2
200 ret = pipe2(pipefd, O_CLOEXEC);
201 if (ret != -1 || errno != ENOSYS) {
202 return ret;
203 }
204 #endif
205 ret = pipe(pipefd);
206 if (ret == 0) {
207 qemu_set_cloexec(pipefd[0]);
208 qemu_set_cloexec(pipefd[1]);
209 }
210
211 return ret;
212 }
213
qemu_utimens(const char * path,const struct timespec * times)214 int qemu_utimens(const char *path, const struct timespec *times)
215 {
216 struct timeval tv[2], tv_now;
217 struct stat st;
218 int i;
219 #ifdef CONFIG_UTIMENSAT
220 int ret;
221
222 ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW);
223 if (ret != -1 || errno != ENOSYS) {
224 return ret;
225 }
226 #endif
227 /* Fallback: use utimes() instead of utimensat() */
228
229 /* happy if special cases */
230 if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) {
231 return 0;
232 }
233 if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) {
234 return utimes(path, NULL);
235 }
236
237 /* prepare for hard cases */
238 if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) {
239 gettimeofday(&tv_now, NULL);
240 }
241 if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) {
242 stat(path, &st);
243 }
244
245 for (i = 0; i < 2; i++) {
246 if (times[i].tv_nsec == UTIME_NOW) {
247 tv[i].tv_sec = tv_now.tv_sec;
248 tv[i].tv_usec = tv_now.tv_usec;
249 } else if (times[i].tv_nsec == UTIME_OMIT) {
250 tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;
251 tv[i].tv_usec = 0;
252 } else {
253 tv[i].tv_sec = times[i].tv_sec;
254 tv[i].tv_usec = times[i].tv_nsec / 1000;
255 }
256 }
257
258 return utimes(path, &tv[0]);
259 }
260
261 char *
qemu_get_local_state_pathname(const char * relative_pathname)262 qemu_get_local_state_pathname(const char *relative_pathname)
263 {
264 #ifdef CONFIG_ANDROID
265 return NULL;
266 #else
267 return g_strdup_printf("%s/%s", CONFIG_QEMU_LOCALSTATEDIR,
268 relative_pathname);
269 #endif
270 }
271