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