Automatic merge of 'misc-fixes' branch from
[linux-2.6] / arch / um / drivers / harddog_user.c
1 /* 
2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5
6 #include <stdio.h>
7 #include <unistd.h>
8 #include <errno.h>
9 #include "user_util.h"
10 #include "user.h"
11 #include "helper.h"
12 #include "mconsole.h"
13 #include "os.h"
14 #include "choose-mode.h"
15 #include "mode.h"
16
17 struct dog_data {
18         int stdin;
19         int stdout;
20         int close_me[2];
21 };
22
23 static void pre_exec(void *d)
24 {
25         struct dog_data *data = d;
26
27         dup2(data->stdin, 0);
28         dup2(data->stdout, 1);
29         dup2(data->stdout, 2);
30         os_close_file(data->stdin);
31         os_close_file(data->stdout);
32         os_close_file(data->close_me[0]);
33         os_close_file(data->close_me[1]);
34 }
35
36 int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
37 {
38         struct dog_data data;
39         int in_fds[2], out_fds[2], pid, n, err;
40         char pid_buf[sizeof("nnnnn\0")], c;
41         char *pid_args[] = { "/usr/bin/uml_watchdog", "-pid", pid_buf, NULL };
42         char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL, 
43                                   NULL };
44         char **args = NULL;
45
46         err = os_pipe(in_fds, 1, 0);
47         if(err < 0){
48                 printk("harddog_open - os_pipe failed, err = %d\n", -err);
49                 goto out;
50         }
51
52         err = os_pipe(out_fds, 1, 0);
53         if(err < 0){
54                 printk("harddog_open - os_pipe failed, err = %d\n", -err);
55                 goto out_close_in;
56         }
57
58         data.stdin = out_fds[0];
59         data.stdout = in_fds[1];
60         data.close_me[0] = out_fds[1];
61         data.close_me[1] = in_fds[0];
62
63         if(sock != NULL){
64                 mconsole_args[2] = sock;
65                 args = mconsole_args;
66         }
67         else {
68                 /* XXX The os_getpid() is not SMP correct */
69                 sprintf(pid_buf, "%d", CHOOSE_MODE(tracing_pid, os_getpid()));
70                 args = pid_args;
71         }
72
73         pid = run_helper(pre_exec, &data, args, NULL);
74
75         os_close_file(out_fds[0]);
76         os_close_file(in_fds[1]);
77
78         if(pid < 0){
79                 err = -pid;
80                 printk("harddog_open - run_helper failed, errno = %d\n", -err);
81                 goto out_close_out;
82         }
83
84         n = os_read_file(in_fds[0], &c, sizeof(c));
85         if(n == 0){
86                 printk("harddog_open - EOF on watchdog pipe\n");
87                 helper_wait(pid);
88                 err = -EIO;
89                 goto out_close_out;
90         }
91         else if(n < 0){
92                 printk("harddog_open - read of watchdog pipe failed, "
93                        "err = %d\n", -n);
94                 helper_wait(pid);
95                 err = n;
96                 goto out_close_out;
97         }
98         *in_fd_ret = in_fds[0];
99         *out_fd_ret = out_fds[1];
100         return(0);
101
102  out_close_in:
103         os_close_file(in_fds[0]);
104         os_close_file(in_fds[1]);
105  out_close_out:
106         os_close_file(out_fds[0]);
107         os_close_file(out_fds[1]);
108  out:
109         return(err);
110 }
111
112 void stop_watchdog(int in_fd, int out_fd)
113 {
114         os_close_file(in_fd);
115         os_close_file(out_fd);
116 }
117
118 int ping_watchdog(int fd)
119 {
120         int n;
121         char c = '\n';
122
123         n = os_write_file(fd, &c, sizeof(c));
124         if(n != sizeof(c)){
125                 printk("ping_watchdog - write failed, err = %d\n", -n);
126                 if(n < 0)
127                         return(n);
128                 return(-EIO);
129         }
130         return 1;
131
132 }
133
134 /*
135  * Overrides for Emacs so that we follow Linus's tabbing style.
136  * Emacs will notice this stuff at the end of the file and automatically
137  * adjust the settings for this buffer only.  This must remain at the end
138  * of the file.
139  * ---------------------------------------------------------------------------
140  * Local variables:
141  * c-file-style: "linux"
142  * End:
143  */