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/*
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* signalfd/eventfd compatibility
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*
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* Copyright IBM, Corp. 2008
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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* Contributions after 2012-01-13 are licensed under the terms of the
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* GNU GPL, version 2 or (at your option) any later version.
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*/
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#include "qemu-common.h" |
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#include "qemu/compatfd.h" |
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#include <sys/syscall.h> |
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#include <pthread.h> |
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struct sigfd_compat_info
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{ |
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sigset_t mask; |
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int fd;
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}; |
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static void *sigwait_compat(void *opaque) |
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{ |
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struct sigfd_compat_info *info = opaque;
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sigset_t all; |
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sigfillset(&all); |
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pthread_sigmask(SIG_BLOCK, &all, NULL);
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while (1) { |
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int sig;
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int err;
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err = sigwait(&info->mask, &sig); |
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if (err != 0) { |
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if (errno == EINTR) {
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continue;
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} else {
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return NULL; |
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} |
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} else {
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struct qemu_signalfd_siginfo buffer;
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size_t offset = 0;
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memset(&buffer, 0, sizeof(buffer)); |
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buffer.ssi_signo = sig; |
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while (offset < sizeof(buffer)) { |
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ssize_t len; |
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len = write(info->fd, (char *)&buffer + offset,
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sizeof(buffer) - offset);
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if (len == -1 && errno == EINTR) |
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continue;
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if (len <= 0) { |
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return NULL; |
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} |
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offset += len; |
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} |
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} |
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} |
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} |
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static int qemu_signalfd_compat(const sigset_t *mask) |
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{ |
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pthread_attr_t attr; |
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pthread_t tid; |
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struct sigfd_compat_info *info;
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int fds[2]; |
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info = malloc(sizeof(*info));
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if (info == NULL) { |
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errno = ENOMEM; |
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return -1; |
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} |
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if (pipe(fds) == -1) { |
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free(info); |
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return -1; |
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} |
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qemu_set_cloexec(fds[0]);
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qemu_set_cloexec(fds[1]);
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memcpy(&info->mask, mask, sizeof(*mask));
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info->fd = fds[1];
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pthread_attr_init(&attr); |
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pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); |
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pthread_create(&tid, &attr, sigwait_compat, info); |
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pthread_attr_destroy(&attr); |
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return fds[0]; |
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} |
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int qemu_signalfd(const sigset_t *mask) |
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{ |
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#if defined(CONFIG_SIGNALFD)
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int ret;
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ret = syscall(SYS_signalfd, -1, mask, _NSIG / 8); |
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if (ret != -1) { |
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qemu_set_cloexec(ret); |
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return ret;
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} |
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#endif
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return qemu_signalfd_compat(mask);
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} |
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bool qemu_signalfd_available(void) |
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{ |
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#ifdef CONFIG_SIGNALFD
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sigset_t mask; |
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int fd;
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bool ok;
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sigemptyset(&mask); |
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errno = 0;
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fd = syscall(SYS_signalfd, -1, &mask, _NSIG / 8); |
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ok = (errno != ENOSYS); |
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if (fd >= 0) { |
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close(fd); |
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} |
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return ok;
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#else
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return false; |
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#endif
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} |