1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4*4882a593Smuzhiyun */
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun #include <stdio.h>
7*4882a593Smuzhiyun #include <unistd.h>
8*4882a593Smuzhiyun #include <errno.h>
9*4882a593Smuzhiyun #include <os.h>
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun struct dog_data {
12*4882a593Smuzhiyun int stdin_fd;
13*4882a593Smuzhiyun int stdout_fd;
14*4882a593Smuzhiyun int close_me[2];
15*4882a593Smuzhiyun };
16*4882a593Smuzhiyun
pre_exec(void * d)17*4882a593Smuzhiyun static void pre_exec(void *d)
18*4882a593Smuzhiyun {
19*4882a593Smuzhiyun struct dog_data *data = d;
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun dup2(data->stdin_fd, 0);
22*4882a593Smuzhiyun dup2(data->stdout_fd, 1);
23*4882a593Smuzhiyun dup2(data->stdout_fd, 2);
24*4882a593Smuzhiyun close(data->stdin_fd);
25*4882a593Smuzhiyun close(data->stdout_fd);
26*4882a593Smuzhiyun close(data->close_me[0]);
27*4882a593Smuzhiyun close(data->close_me[1]);
28*4882a593Smuzhiyun }
29*4882a593Smuzhiyun
start_watchdog(int * in_fd_ret,int * out_fd_ret,char * sock)30*4882a593Smuzhiyun int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
31*4882a593Smuzhiyun {
32*4882a593Smuzhiyun struct dog_data data;
33*4882a593Smuzhiyun int in_fds[2], out_fds[2], pid, n, err;
34*4882a593Smuzhiyun char pid_buf[sizeof("nnnnnnn\0")], c;
35*4882a593Smuzhiyun char *pid_args[] = { "/usr/bin/uml_watchdog", "-pid", pid_buf, NULL };
36*4882a593Smuzhiyun char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL,
37*4882a593Smuzhiyun NULL };
38*4882a593Smuzhiyun char **args = NULL;
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun err = os_pipe(in_fds, 1, 0);
41*4882a593Smuzhiyun if (err < 0) {
42*4882a593Smuzhiyun printk("harddog_open - os_pipe failed, err = %d\n", -err);
43*4882a593Smuzhiyun goto out;
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun err = os_pipe(out_fds, 1, 0);
47*4882a593Smuzhiyun if (err < 0) {
48*4882a593Smuzhiyun printk("harddog_open - os_pipe failed, err = %d\n", -err);
49*4882a593Smuzhiyun goto out_close_in;
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun data.stdin_fd = out_fds[0];
53*4882a593Smuzhiyun data.stdout_fd = in_fds[1];
54*4882a593Smuzhiyun data.close_me[0] = out_fds[1];
55*4882a593Smuzhiyun data.close_me[1] = in_fds[0];
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun if (sock != NULL) {
58*4882a593Smuzhiyun mconsole_args[2] = sock;
59*4882a593Smuzhiyun args = mconsole_args;
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun else {
62*4882a593Smuzhiyun /* XXX The os_getpid() is not SMP correct */
63*4882a593Smuzhiyun sprintf(pid_buf, "%d", os_getpid());
64*4882a593Smuzhiyun args = pid_args;
65*4882a593Smuzhiyun }
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun pid = run_helper(pre_exec, &data, args);
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun close(out_fds[0]);
70*4882a593Smuzhiyun close(in_fds[1]);
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun if (pid < 0) {
73*4882a593Smuzhiyun err = -pid;
74*4882a593Smuzhiyun printk("harddog_open - run_helper failed, errno = %d\n", -err);
75*4882a593Smuzhiyun goto out_close_out;
76*4882a593Smuzhiyun }
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun n = read(in_fds[0], &c, sizeof(c));
79*4882a593Smuzhiyun if (n == 0) {
80*4882a593Smuzhiyun printk("harddog_open - EOF on watchdog pipe\n");
81*4882a593Smuzhiyun helper_wait(pid);
82*4882a593Smuzhiyun err = -EIO;
83*4882a593Smuzhiyun goto out_close_out;
84*4882a593Smuzhiyun }
85*4882a593Smuzhiyun else if (n < 0) {
86*4882a593Smuzhiyun printk("harddog_open - read of watchdog pipe failed, "
87*4882a593Smuzhiyun "err = %d\n", errno);
88*4882a593Smuzhiyun helper_wait(pid);
89*4882a593Smuzhiyun err = n;
90*4882a593Smuzhiyun goto out_close_out;
91*4882a593Smuzhiyun }
92*4882a593Smuzhiyun *in_fd_ret = in_fds[0];
93*4882a593Smuzhiyun *out_fd_ret = out_fds[1];
94*4882a593Smuzhiyun return 0;
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun out_close_in:
97*4882a593Smuzhiyun close(in_fds[0]);
98*4882a593Smuzhiyun close(in_fds[1]);
99*4882a593Smuzhiyun out_close_out:
100*4882a593Smuzhiyun close(out_fds[0]);
101*4882a593Smuzhiyun close(out_fds[1]);
102*4882a593Smuzhiyun out:
103*4882a593Smuzhiyun return err;
104*4882a593Smuzhiyun }
105*4882a593Smuzhiyun
stop_watchdog(int in_fd,int out_fd)106*4882a593Smuzhiyun void stop_watchdog(int in_fd, int out_fd)
107*4882a593Smuzhiyun {
108*4882a593Smuzhiyun close(in_fd);
109*4882a593Smuzhiyun close(out_fd);
110*4882a593Smuzhiyun }
111*4882a593Smuzhiyun
ping_watchdog(int fd)112*4882a593Smuzhiyun int ping_watchdog(int fd)
113*4882a593Smuzhiyun {
114*4882a593Smuzhiyun int n;
115*4882a593Smuzhiyun char c = '\n';
116*4882a593Smuzhiyun
117*4882a593Smuzhiyun n = write(fd, &c, sizeof(c));
118*4882a593Smuzhiyun if (n != sizeof(c)) {
119*4882a593Smuzhiyun printk("ping_watchdog - write failed, ret = %d, err = %d\n",
120*4882a593Smuzhiyun n, errno);
121*4882a593Smuzhiyun if (n < 0)
122*4882a593Smuzhiyun return n;
123*4882a593Smuzhiyun return -EIO;
124*4882a593Smuzhiyun }
125*4882a593Smuzhiyun return 1;
126*4882a593Smuzhiyun
127*4882a593Smuzhiyun }
128