/* * 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__) /* 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) # define CONFIG_VALGRIND #else # define QEMU_VMALLOC_ALIGN getpagesize() #endif #include "config-host.h" #include "sysemu.h" #include "trace.h" #include "qemu_socket.h" #if defined(CONFIG_VALGRIND) static int running_on_valgrind = -1; #else # define running_on_valgrind 0 #endif #ifdef CONFIG_LINUX #include <sys/syscall.h> #endif #ifdef CONFIG_EVENTFD #include <sys/eventfd.h> #endif 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_memalign(size_t alignment, size_t size) { void *ptr; #if defined(_POSIX_C_SOURCE) && !defined(__sun__) int ret; ret = posix_memalign(&ptr, alignment, size); if (ret != 0) { fprintf(stderr, "Failed to allocate %zu B: %s\n", size, strerror(ret)); abort(); } #elif defined(CONFIG_BSD) ptr = qemu_oom_check(valloc(size)); #else ptr = qemu_oom_check(memalign(alignment, size)); #endif trace_qemu_memalign(alignment, size, ptr); return ptr; } /* alloc shared memory pages */ void *qemu_vmalloc(size_t size) { void *ptr; size_t align = QEMU_VMALLOC_ALIGN; #if defined(CONFIG_VALGRIND) if (running_on_valgrind < 0) { /* First call, test whether we are running on Valgrind. This is a substitute for RUNNING_ON_VALGRIND from valgrind.h. */ const char *ld = getenv("LD_PRELOAD"); running_on_valgrind = (ld != NULL && strstr(ld, "vgpreload")); } #endif if (size < align || running_on_valgrind) { align = getpagesize(); } ptr = qemu_memalign(align, size); trace_qemu_vmalloc(size, ptr); return ptr; } void qemu_vfree(void *ptr) { trace_qemu_vfree(ptr); free(ptr); } void socket_set_block(int fd) { int f; f = fcntl(fd, F_GETFL); fcntl(fd, F_SETFL, f & ~O_NONBLOCK); } void socket_set_nonblock(int fd) { int f; f = fcntl(fd, F_GETFL); fcntl(fd, F_SETFL, f | O_NONBLOCK); } 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; } /* * Creates an eventfd that looks like a pipe and has EFD_CLOEXEC set. */ int qemu_eventfd(int fds[2]) { #ifdef CONFIG_EVENTFD int ret; ret = eventfd(0, 0); if (ret >= 0) { fds[0] = ret; fds[1] = dup(ret); if (fds[1] == -1) { close(ret); return -1; } qemu_set_cloexec(ret); qemu_set_cloexec(fds[1]); return 0; } if (errno != ENOSYS) { return -1; } #endif return qemu_pipe(fds); } 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]); }