1 files changed, 127 insertions, 0 deletions
diff --git a/arch/um/drivers/harddog_user.c b/arch/um/drivers/harddog_user.c
new file mode 100644
index 000000000..070468d22
--- /dev/null
+++ b/arch/um/drivers/harddog_user.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <os.h>
+
+struct dog_data {
+	int stdin_fd;
+	int stdout_fd;
+	int close_me[2];
+};
+
+static void pre_exec(void *d)
+{
+	struct dog_data *data = d;
+
+	dup2(data->stdin_fd, 0);
+	dup2(data->stdout_fd, 1);
+	dup2(data->stdout_fd, 2);
+	close(data->stdin_fd);
+	close(data->stdout_fd);
+	close(data->close_me[0]);
+	close(data->close_me[1]);
+}
+
+int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
+{
+	struct dog_data data;
+	int in_fds[2], out_fds[2], pid, n, err;
+	char pid_buf[sizeof("nnnnnnn\0")], c;
+	char *pid_args[] = { "/usr/bin/uml_watchdog", "-pid", pid_buf, NULL };
+	char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL,
+				  NULL };
+	char **args = NULL;
+
+	err = os_pipe(in_fds, 1, 0);
+	if (err < 0) {
+		printk("harddog_open - os_pipe failed, err = %d\n", -err);
+		goto out;
+	}
+
+	err = os_pipe(out_fds, 1, 0);
+	if (err < 0) {
+		printk("harddog_open - os_pipe failed, err = %d\n", -err);
+		goto out_close_in;
+	}
+
+	data.stdin_fd = out_fds[0];
+	data.stdout_fd = in_fds[1];
+	data.close_me[0] = out_fds[1];
+	data.close_me[1] = in_fds[0];
+
+	if (sock != NULL) {
+		mconsole_args[2] = sock;
+		args = mconsole_args;
+	}
+	else {
+		/* XXX The os_getpid() is not SMP correct */
+		sprintf(pid_buf, "%d", os_getpid());
+		args = pid_args;
+	}
+
+	pid = run_helper(pre_exec, &data, args);
+
+	close(out_fds[0]);
+	close(in_fds[1]);
+
+	if (pid < 0) {
+		err = -pid;
+		printk("harddog_open - run_helper failed, errno = %d\n", -err);
+		goto out_close_out;
+	}
+
+	n = read(in_fds[0], &c, sizeof(c));
+	if (n == 0) {
+		printk("harddog_open - EOF on watchdog pipe\n");
+		helper_wait(pid);
+		err = -EIO;
+		goto out_close_out;
+	}
+	else if (n < 0) {
+		printk("harddog_open - read of watchdog pipe failed, "
+		       "err = %d\n", errno);
+		helper_wait(pid);
+		err = n;
+		goto out_close_out;
+	}
+	*in_fd_ret = in_fds[0];
+	*out_fd_ret = out_fds[1];
+	return 0;
+
+ out_close_in:
+	close(in_fds[0]);
+	close(in_fds[1]);
+ out_close_out:
+	close(out_fds[0]);
+	close(out_fds[1]);
+ out:
+	return err;
+}
+
+void stop_watchdog(int in_fd, int out_fd)
+{
+	close(in_fd);
+	close(out_fd);
+}
+
+int ping_watchdog(int fd)
+{
+	int n;
+	char c = '\n';
+
+	n = write(fd, &c, sizeof(c));
+	if (n != sizeof(c)) {
+		printk("ping_watchdog - write failed, ret = %d, err = %d\n",
+		       n, errno);
+		if (n < 0)
+			return n;
+		return -EIO;
+	}
+	return 1;
+
+}