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 <termios.h> 51 #include <unistd.h> 52 53 #include <glib/gprintf.h> 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 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 74 int qemu_daemon(int nochdir, int noclose) 75 { 76 return daemon(nochdir, noclose); 77 } 78 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 88 void *qemu_memalign(size_t alignment, size_t size) 89 { 90 void *ptr; 91 92 if (alignment < sizeof(void*)) { 93 alignment = sizeof(void*); 94 } 95 96 #if defined(_POSIX_C_SOURCE) && !defined(__sun__) 97 int ret; 98 ret = posix_memalign(&ptr, alignment, size); 99 if (ret != 0) { 100 fprintf(stderr, "Failed to allocate %zu B: %s\n", 101 size, strerror(ret)); 102 abort(); 103 } 104 #elif defined(CONFIG_BSD) 105 ptr = qemu_oom_check(valloc(size)); 106 #else 107 ptr = qemu_oom_check(memalign(alignment, size)); 108 #endif 109 trace_qemu_memalign(alignment, size, ptr); 110 return ptr; 111 } 112 113 /* alloc shared memory pages */ 114 void *qemu_anon_ram_alloc(size_t size) 115 { 116 size_t align = QEMU_VMALLOC_ALIGN; 117 size_t total = size + align - getpagesize(); 118 void *ptr = mmap(0, total, PROT_READ | PROT_WRITE, 119 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); 120 size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr; 121 122 if (ptr == MAP_FAILED) { 123 return NULL; 124 } 125 126 ptr += offset; 127 total -= offset; 128 129 if (offset > 0) { 130 munmap(ptr - offset, offset); 131 } 132 if (total > size) { 133 munmap(ptr + size, total - size); 134 } 135 136 trace_qemu_anon_ram_alloc(size, ptr); 137 return ptr; 138 } 139 140 void qemu_vfree(void *ptr) 141 { 142 trace_qemu_vfree(ptr); 143 free(ptr); 144 } 145 146 void qemu_anon_ram_free(void *ptr, size_t size) 147 { 148 trace_qemu_anon_ram_free(ptr, size); 149 if (ptr) { 150 munmap(ptr, size); 151 } 152 } 153 154 void qemu_set_block(int fd) 155 { 156 int f; 157 f = fcntl(fd, F_GETFL); 158 fcntl(fd, F_SETFL, f & ~O_NONBLOCK); 159 } 160 161 void qemu_set_nonblock(int fd) 162 { 163 int f; 164 f = fcntl(fd, F_GETFL); 165 fcntl(fd, F_SETFL, f | O_NONBLOCK); 166 } 167 168 int socket_set_fast_reuse(int fd) 169 { 170 int val = 1, ret; 171 172 ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, 173 (const char *)&val, sizeof(val)); 174 175 assert(ret == 0); 176 177 return ret; 178 } 179 180 void qemu_set_cloexec(int fd) 181 { 182 int f; 183 f = fcntl(fd, F_GETFD); 184 fcntl(fd, F_SETFD, f | FD_CLOEXEC); 185 } 186 187 /* 188 * Creates a pipe with FD_CLOEXEC set on both file descriptors 189 */ 190 int qemu_pipe(int pipefd[2]) 191 { 192 int ret; 193 194 #ifdef CONFIG_PIPE2 195 ret = pipe2(pipefd, O_CLOEXEC); 196 if (ret != -1 || errno != ENOSYS) { 197 return ret; 198 } 199 #endif 200 ret = pipe(pipefd); 201 if (ret == 0) { 202 qemu_set_cloexec(pipefd[0]); 203 qemu_set_cloexec(pipefd[1]); 204 } 205 206 return ret; 207 } 208 209 int qemu_utimens(const char *path, const struct timespec *times) 210 { 211 struct timeval tv[2], tv_now; 212 struct stat st; 213 int i; 214 #ifdef CONFIG_UTIMENSAT 215 int ret; 216 217 ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW); 218 if (ret != -1 || errno != ENOSYS) { 219 return ret; 220 } 221 #endif 222 /* Fallback: use utimes() instead of utimensat() */ 223 224 /* happy if special cases */ 225 if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) { 226 return 0; 227 } 228 if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) { 229 return utimes(path, NULL); 230 } 231 232 /* prepare for hard cases */ 233 if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) { 234 gettimeofday(&tv_now, NULL); 235 } 236 if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) { 237 stat(path, &st); 238 } 239 240 for (i = 0; i < 2; i++) { 241 if (times[i].tv_nsec == UTIME_NOW) { 242 tv[i].tv_sec = tv_now.tv_sec; 243 tv[i].tv_usec = tv_now.tv_usec; 244 } else if (times[i].tv_nsec == UTIME_OMIT) { 245 tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime; 246 tv[i].tv_usec = 0; 247 } else { 248 tv[i].tv_sec = times[i].tv_sec; 249 tv[i].tv_usec = times[i].tv_nsec / 1000; 250 } 251 } 252 253 return utimes(path, &tv[0]); 254 } 255 256 char * 257 qemu_get_local_state_pathname(const char *relative_pathname) 258 { 259 return g_strdup_printf("%s/%s", CONFIG_QEMU_LOCALSTATEDIR, 260 relative_pathname); 261 } 262 263 void qemu_set_tty_echo(int fd, bool echo) 264 { 265 struct termios tty; 266 267 tcgetattr(fd, &tty); 268 269 if (echo) { 270 tty.c_lflag |= ECHO | ECHONL | ICANON | IEXTEN; 271 } else { 272 tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN); 273 } 274 275 tcsetattr(fd, TCSANOW, &tty); 276 } 277