qemu

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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/osdep.h"
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#include "qemu/thread.h"
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#if defined(CONFIG_SIGNALFD)
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#include <sys/signalfd.h>
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#endif
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struct sigfd_compat_info {
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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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    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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            memset(&buffer, 0, sizeof(buffer));
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            buffer.ssi_signo = sig;
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            if (qemu_write_full(info->fd, &buffer, sizeof(buffer)) != sizeof(buffer)) {
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                return NULL;
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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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    struct sigfd_compat_info *info;
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    QemuThread thread;
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    int fds[2];
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    info = g_malloc(sizeof(*info));
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    if (!g_unix_open_pipe(fds, FD_CLOEXEC, NULL)) {
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        g_free(info);
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        return -1;
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    }
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    memcpy(&info->mask, mask, sizeof(*mask));
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    info->fd = fds[1];
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    qemu_thread_create(&thread, "signalfd_compat", sigwait_compat, info,
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                       QEMU_THREAD_DETACHED);
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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 = signalfd(-1, mask, SFD_CLOEXEC);
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    if (ret != -1) {
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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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