root / oslib-posix.c @ e3e87df4
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/*
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* os-posix-lib.c
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*
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* Copyright (c) 2003-2008 Fabrice Bellard
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* Copyright (c) 2010 Red Hat, Inc.
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*
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* QEMU library functions on POSIX which are shared between QEMU and
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* the QEMU tools.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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/* The following block of code temporarily renames the daemon() function so the
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compiler does not see the warning associated with it in stdlib.h on OSX */
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#ifdef __APPLE__
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#define daemon qemu_fake_daemon_function
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#include <stdlib.h> |
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#undef daemon
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extern int daemon(int, int); |
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#endif
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#if defined(__linux__) && defined(__x86_64__)
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/* Use 2 MiB alignment so transparent hugepages can be used by KVM.
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Valgrind does not support alignments larger than 1 MiB,
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therefore we need special code which handles running on Valgrind. */
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# define QEMU_VMALLOC_ALIGN (512 * 4096) |
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# define CONFIG_VALGRIND
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#else
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# define QEMU_VMALLOC_ALIGN getpagesize()
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#endif
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#include "config-host.h" |
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#include "sysemu.h" |
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#include "trace.h" |
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#include "qemu_socket.h" |
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#if defined(CONFIG_VALGRIND)
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static int running_on_valgrind = -1; |
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#else
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# define running_on_valgrind 0 |
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#endif
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#ifdef CONFIG_LINUX
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#include <sys/syscall.h> |
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#endif
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#ifdef CONFIG_EVENTFD
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#include <sys/eventfd.h> |
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#endif
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int qemu_get_thread_id(void) |
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{ |
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#if defined(__linux__)
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return syscall(SYS_gettid);
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#else
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return getpid();
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#endif
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} |
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int qemu_daemon(int nochdir, int noclose) |
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{ |
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return daemon(nochdir, noclose);
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} |
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void *qemu_oom_check(void *ptr) |
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{ |
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if (ptr == NULL) { |
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fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
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abort(); |
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} |
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return ptr;
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} |
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void *qemu_memalign(size_t alignment, size_t size)
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{ |
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void *ptr;
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#if defined(_POSIX_C_SOURCE) && !defined(__sun__)
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int ret;
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ret = posix_memalign(&ptr, alignment, size); |
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if (ret != 0) { |
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fprintf(stderr, "Failed to allocate %zu B: %s\n",
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size, strerror(ret)); |
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abort(); |
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} |
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#elif defined(CONFIG_BSD)
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ptr = qemu_oom_check(valloc(size)); |
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#else
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ptr = qemu_oom_check(memalign(alignment, size)); |
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#endif
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trace_qemu_memalign(alignment, size, ptr); |
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return ptr;
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} |
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/* alloc shared memory pages */
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void *qemu_vmalloc(size_t size)
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{ |
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void *ptr;
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size_t align = QEMU_VMALLOC_ALIGN; |
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#if defined(CONFIG_VALGRIND)
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if (running_on_valgrind < 0) { |
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/* First call, test whether we are running on Valgrind.
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This is a substitute for RUNNING_ON_VALGRIND from valgrind.h. */
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const char *ld = getenv("LD_PRELOAD"); |
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running_on_valgrind = (ld != NULL && strstr(ld, "vgpreload")); |
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} |
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#endif
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if (size < align || running_on_valgrind) {
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align = getpagesize(); |
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} |
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ptr = qemu_memalign(align, size); |
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trace_qemu_vmalloc(size, ptr); |
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return ptr;
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} |
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void qemu_vfree(void *ptr) |
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{ |
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trace_qemu_vfree(ptr); |
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free(ptr); |
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} |
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void socket_set_block(int fd) |
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{ |
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int f;
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f = fcntl(fd, F_GETFL); |
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fcntl(fd, F_SETFL, f & ~O_NONBLOCK); |
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} |
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void socket_set_nonblock(int fd) |
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{ |
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int f;
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f = fcntl(fd, F_GETFL); |
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fcntl(fd, F_SETFL, f | O_NONBLOCK); |
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} |
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void qemu_set_cloexec(int fd) |
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{ |
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int f;
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f = fcntl(fd, F_GETFD); |
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fcntl(fd, F_SETFD, f | FD_CLOEXEC); |
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} |
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/*
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* Creates a pipe with FD_CLOEXEC set on both file descriptors
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*/
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int qemu_pipe(int pipefd[2]) |
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{ |
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int ret;
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#ifdef CONFIG_PIPE2
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ret = pipe2(pipefd, O_CLOEXEC); |
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if (ret != -1 || errno != ENOSYS) { |
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return ret;
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} |
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#endif
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ret = pipe(pipefd); |
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if (ret == 0) { |
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qemu_set_cloexec(pipefd[0]);
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qemu_set_cloexec(pipefd[1]);
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} |
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return ret;
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} |
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/*
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* Creates an eventfd that looks like a pipe and has EFD_CLOEXEC set.
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*/
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int qemu_eventfd(int fds[2]) |
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{ |
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#ifdef CONFIG_EVENTFD
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int ret;
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ret = eventfd(0, 0); |
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if (ret >= 0) { |
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fds[0] = ret;
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fds[1] = dup(ret);
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if (fds[1] == -1) { |
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close(ret); |
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return -1; |
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} |
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qemu_set_cloexec(ret); |
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qemu_set_cloexec(fds[1]);
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return 0; |
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} |
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if (errno != ENOSYS) {
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return -1; |
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} |
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#endif
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return qemu_pipe(fds);
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} |
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int qemu_utimens(const char *path, const struct timespec *times) |
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{ |
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struct timeval tv[2], tv_now; |
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struct stat st;
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int i;
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#ifdef CONFIG_UTIMENSAT
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int ret;
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ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW); |
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if (ret != -1 || errno != ENOSYS) { |
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return ret;
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} |
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#endif
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/* Fallback: use utimes() instead of utimensat() */
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/* happy if special cases */
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if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) { |
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return 0; |
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} |
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if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) { |
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return utimes(path, NULL); |
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} |
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/* prepare for hard cases */
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if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) { |
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gettimeofday(&tv_now, NULL);
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} |
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if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) { |
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stat(path, &st); |
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} |
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for (i = 0; i < 2; i++) { |
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if (times[i].tv_nsec == UTIME_NOW) {
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tv[i].tv_sec = tv_now.tv_sec; |
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tv[i].tv_usec = tv_now.tv_usec; |
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} else if (times[i].tv_nsec == UTIME_OMIT) { |
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tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;
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tv[i].tv_usec = 0;
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} else {
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tv[i].tv_sec = times[i].tv_sec; |
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tv[i].tv_usec = times[i].tv_nsec / 1000;
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} |
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} |
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return utimes(path, &tv[0]); |
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} |