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-rw-r--r--qemu/util/compatfd.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/qemu/util/compatfd.c b/qemu/util/compatfd.c
new file mode 100644
index 000000000..e8571502b
--- /dev/null
+++ b/qemu/util/compatfd.c
@@ -0,0 +1,110 @@
+/*
+ * signalfd/eventfd compatibility
+ *
+ * Copyright IBM, Corp. 2008
+ *
+ * Authors:
+ * Anthony Liguori <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+
+#include "qemu-common.h"
+#include "qemu/compatfd.h"
+#include "qemu/thread.h"
+
+#include <sys/syscall.h>
+
+struct sigfd_compat_info
+{
+ sigset_t mask;
+ int fd;
+};
+
+static void *sigwait_compat(void *opaque)
+{
+ struct sigfd_compat_info *info = opaque;
+
+ while (1) {
+ int sig;
+ int err;
+
+ err = sigwait(&info->mask, &sig);
+ if (err != 0) {
+ if (errno == EINTR) {
+ continue;
+ } else {
+ return NULL;
+ }
+ } else {
+ struct qemu_signalfd_siginfo buffer;
+ size_t offset = 0;
+
+ memset(&buffer, 0, sizeof(buffer));
+ buffer.ssi_signo = sig;
+
+ while (offset < sizeof(buffer)) {
+ ssize_t len;
+
+ len = write(info->fd, (char *)&buffer + offset,
+ sizeof(buffer) - offset);
+ if (len == -1 && errno == EINTR)
+ continue;
+
+ if (len <= 0) {
+ return NULL;
+ }
+
+ offset += len;
+ }
+ }
+ }
+}
+
+static int qemu_signalfd_compat(const sigset_t *mask)
+{
+ struct sigfd_compat_info *info;
+ QemuThread thread;
+ int fds[2];
+
+ info = malloc(sizeof(*info));
+ if (info == NULL) {
+ errno = ENOMEM;
+ return -1;
+ }
+
+ if (pipe(fds) == -1) {
+ free(info);
+ return -1;
+ }
+
+ qemu_set_cloexec(fds[0]);
+ qemu_set_cloexec(fds[1]);
+
+ memcpy(&info->mask, mask, sizeof(*mask));
+ info->fd = fds[1];
+
+ qemu_thread_create(&thread, "signalfd_compat", sigwait_compat, info,
+ QEMU_THREAD_DETACHED);
+
+ return fds[0];
+}
+
+int qemu_signalfd(const sigset_t *mask)
+{
+#if defined(CONFIG_SIGNALFD)
+ int ret;
+
+ ret = syscall(SYS_signalfd, -1, mask, _NSIG / 8);
+ if (ret != -1) {
+ qemu_set_cloexec(ret);
+ return ret;
+ }
+#endif
+
+ return qemu_signalfd_compat(mask);
+}