/* * os-posix-lib.c * * Copyright (c) 2003-2008 Fabrice Bellard * Copyright (c) 2010 Red Hat, Inc. * * QEMU library functions on POSIX which are shared between QEMU and * the QEMU tools. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ /* The following block of code temporarily renames the daemon() function so the compiler does not see the warning associated with it in stdlib.h on OSX */ #ifdef __APPLE__ #define daemon qemu_fake_daemon_function #include <stdlib.h> #undef daemon extern int daemon(int, int); #endif #if defined(__linux__) && (defined(__x86_64__) || defined(__arm__)) /* Use 2 MiB alignment so transparent hugepages can be used by KVM. Valgrind does not support alignments larger than 1 MiB, therefore we need special code which handles running on Valgrind. */ # define QEMU_VMALLOC_ALIGN (512 * 4096) #elif defined(__linux__) && defined(__s390x__) /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */ # define QEMU_VMALLOC_ALIGN (256 * 4096) #else # define QEMU_VMALLOC_ALIGN getpagesize() #endif #include <termios.h> #include <unistd.h> #include <termios.h> #include <glib/gprintf.h> #include "config-host.h" #include "sysemu/sysemu.h" #include "trace.h" #include "qemu/sockets.h" #include <sys/mman.h> #include <libgen.h> #include <setjmp.h> #include <sys/signal.h> #ifdef CONFIG_LINUX #include <sys/syscall.h> #endif #ifdef __FreeBSD__ #include <sys/sysctl.h> #endif #include <qemu/mmap-alloc.h> int qemu_get_thread_id(void) { #if defined(__linux__) return syscall(SYS_gettid); #else return getpid(); #endif } int qemu_daemon(int nochdir, int noclose) { return daemon(nochdir, noclose); } void *qemu_oom_check(void *ptr) { if (ptr == NULL) { fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno)); abort(); } return ptr; } void *qemu_try_memalign(size_t alignment, size_t size) { void *ptr; if (alignment < sizeof(void*)) { alignment = sizeof(void*); } #if defined(_POSIX_C_SOURCE) && !defined(__sun__) int ret; ret = posix_memalign(&ptr, alignment, size); if (ret != 0) { errno = ret; ptr = NULL; } #elif defined(CONFIG_BSD) ptr = valloc(size); #else ptr = memalign(alignment, size); #endif trace_qemu_memalign(alignment, size, ptr); return ptr; } void *qemu_memalign(size_t alignment, size_t size) { return qemu_oom_check(qemu_try_memalign(alignment, size)); } /* alloc shared memory pages */ void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment) { size_t align = QEMU_VMALLOC_ALIGN; void *ptr = qemu_ram_mmap(-1, size, align, false); if (ptr == MAP_FAILED) { return NULL; } if (alignment) { *alignment = align; } trace_qemu_anon_ram_alloc(size, ptr); return ptr; } void qemu_vfree(void *ptr) { trace_qemu_vfree(ptr); free(ptr); } void qemu_anon_ram_free(void *ptr, size_t size) { trace_qemu_anon_ram_free(ptr, size); qemu_ram_munmap(ptr, size); } void qemu_set_block(int fd) { int f; f = fcntl(fd, F_GETFL); fcntl(fd, F_SETFL, f & ~O_NONBLOCK); } void qemu_set_nonblock(int fd) { int f; f = fcntl(fd, F_GETFL); fcntl(fd, F_SETFL, f | O_NONBLOCK); } int socket_set_fast_reuse(int fd) { int val = 1, ret; ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val)); assert(ret == 0); return ret; } void qemu_set_cloexec(int fd) { int f; f = fcntl(fd, F_GETFD); fcntl(fd, F_SETFD, f | FD_CLOEXEC); } /* * Creates a pipe with FD_CLOEXEC set on both file descriptors */ int qemu_pipe(int pipefd[2]) { int ret; #ifdef CONFIG_PIPE2 ret = pipe2(pipefd, O_CLOEXEC); if (ret != -1 || errno != ENOSYS) { return ret; } #endif ret = pipe(pipefd); if (ret == 0) { qemu_set_cloexec(pipefd[0]); qemu_set_cloexec(pipefd[1]); } return ret; } int qemu_utimens(const char *path, const struct timespec *times) { struct timeval tv[2], tv_now; struct stat st; int i; #ifdef CONFIG_UTIMENSAT int ret; ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW); if (ret != -1 || errno != ENOSYS) { return ret; } #endif /* Fallback: use utimes() instead of utimensat() */ /* happy if special cases */ if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) { return 0; } if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) { return utimes(path, NULL); } /* prepare for hard cases */ if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) { gettimeofday(&tv_now, NULL); } if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) { stat(path, &st); } for (i = 0; i < 2; i++) { if (times[i].tv_nsec == UTIME_NOW) { tv[i].tv_sec = tv_now.tv_sec; tv[i].tv_usec = tv_now.tv_usec; } else if (times[i].tv_nsec == UTIME_OMIT) { tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime; tv[i].tv_usec = 0; } else { tv[i].tv_sec = times[i].tv_sec; tv[i].tv_usec = times[i].tv_nsec / 1000; } } return utimes(path, &tv[0]); } char * qemu_get_local_state_pathname(const char *relative_pathname) { return g_strdup_printf("%s/%s", CONFIG_QEMU_LOCALSTATEDIR, relative_pathname); } void qemu_set_tty_echo(int fd, bool echo) { struct termios tty; tcgetattr(fd, &tty); if (echo) { tty.c_lflag |= ECHO | ECHONL | ICANON | IEXTEN; } else { tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN); } tcsetattr(fd, TCSANOW, &tty); } static char exec_dir[PATH_MAX]; void qemu_init_exec_dir(const char *argv0) { char *dir; char *p = NULL; char buf[PATH_MAX]; assert(!exec_dir[0]); #if defined(__linux__) { int len; len = readlink("/proc/self/exe", buf, sizeof(buf) - 1); if (len > 0) { buf[len] = 0; p = buf; } } #elif defined(__FreeBSD__) { static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1}; size_t len = sizeof(buf) - 1; *buf = '\0'; if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) && *buf) { buf[sizeof(buf) - 1] = '\0'; p = buf; } } #endif /* If we don't have any way of figuring out the actual executable location then try argv[0]. */ if (!p) { if (!argv0) { return; } p = realpath(argv0, buf); if (!p) { return; } } dir = dirname(p); pstrcpy(exec_dir, sizeof(exec_dir), dir); } char *qemu_get_exec_dir(void) { return g_strdup(exec_dir); } static sigjmp_buf sigjump; static void sigbus_handler(int signal) { siglongjmp(sigjump, 1); } void os_mem_prealloc(int fd, char *area, size_t memory) { int ret; struct sigaction act, oldact; sigset_t set, oldset; memset(&act, 0, sizeof(act)); act.sa_handler = &sigbus_handler; act.sa_flags = 0; ret = sigaction(SIGBUS, &act, &oldact); if (ret) { perror("os_mem_prealloc: failed to install signal handler"); exit(1); } /* unblock SIGBUS */ sigemptyset(&set); sigaddset(&set, SIGBUS); pthread_sigmask(SIG_UNBLOCK, &set, &oldset); if (sigsetjmp(sigjump, 1)) { fprintf(stderr, "os_mem_prealloc: Insufficient free host memory " "pages available to allocate guest RAM\n"); exit(1); } else { int i; size_t hpagesize = qemu_fd_getpagesize(fd); size_t numpages = DIV_ROUND_UP(memory, hpagesize); /* MAP_POPULATE silently ignores failures */ for (i = 0; i < numpages; i++) { memset(area + (hpagesize * i), 0, 1); } ret = sigaction(SIGBUS, &oldact, NULL); if (ret) { perror("os_mem_prealloc: failed to reinstall signal handler"); exit(1); } pthread_sigmask(SIG_SETMASK, &oldset, NULL); } } static struct termios oldtty; static void term_exit(void) { tcsetattr(0, TCSANOW, &oldtty); } static void term_init(void) { struct termios tty; tcgetattr(0, &tty); oldtty = tty; tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP |INLCR|IGNCR|ICRNL|IXON); tty.c_oflag |= OPOST; tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN); tty.c_cflag &= ~(CSIZE|PARENB); tty.c_cflag |= CS8; tty.c_cc[VMIN] = 1; tty.c_cc[VTIME] = 0; tcsetattr(0, TCSANOW, &tty); atexit(term_exit); } int qemu_read_password(char *buf, int buf_size) { uint8_t ch; int i, ret; printf("password: "); fflush(stdout); term_init(); i = 0; for (;;) { ret = read(0, &ch, 1); if (ret == -1) { if (errno == EAGAIN || errno == EINTR) { continue; } else { break; } } else if (ret == 0) { ret = -1; break; } else { if (ch == '\r' || ch == '\n') { ret = 0; break; } if (i < (buf_size - 1)) { buf[i++] = ch; } } } term_exit(); buf[i] = '\0'; printf("\n"); return ret; } pid_t qemu_fork(Error **errp) { sigset_t oldmask, newmask; struct sigaction sig_action; int saved_errno; pid_t pid; /* * Need to block signals now, so that child process can safely * kill off caller's signal handlers without a race. */ sigfillset(&newmask); if (pthread_sigmask(SIG_SETMASK, &newmask, &oldmask) != 0) { error_setg_errno(errp, errno, "cannot block signals"); return -1; } pid = fork(); saved_errno = errno; if (pid < 0) { /* attempt to restore signal mask, but ignore failure, to * avoid obscuring the fork failure */ (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL); error_setg_errno(errp, saved_errno, "cannot fork child process"); errno = saved_errno; return -1; } else if (pid) { /* parent process */ /* Restore our original signal mask now that the child is * safely running. Only documented failures are EFAULT (not * possible, since we are using just-grabbed mask) or EINVAL * (not possible, since we are using correct arguments). */ (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL); } else { /* child process */ size_t i; /* Clear out all signal handlers from parent so nothing * unexpected can happen in our child once we unblock * signals */ sig_action.sa_handler = SIG_DFL; sig_action.sa_flags = 0; sigemptyset(&sig_action.sa_mask); for (i = 1; i < NSIG; i++) { /* Only possible errors are EFAULT or EINVAL The former * won't happen, the latter we expect, so no need to check * return value */ (void)sigaction(i, &sig_action, NULL); } /* Unmask all signals in child, since we've no idea what the * caller's done with their signal mask and don't want to * propagate that to children */ sigemptyset(&newmask); if (pthread_sigmask(SIG_SETMASK, &newmask, NULL) != 0) { Error *local_err = NULL; error_setg_errno(&local_err, errno, "cannot unblock signals"); error_report_err(local_err); _exit(1); } } return pid; }