SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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.h"
  10 #include "mconsole.h"
  11 #include "os.h"
  12
  13 struct dog_data {
  14         int stdin;
  15         int stdout;
  16         int close_me[2];
  17 };
  18
  19 static void pre_exec(void *d)
  20 {
  21         struct dog_data *data = d;
  22
  23         dup2(data->stdin, 0);
  24         dup2(data->stdout, 1);
  25         dup2(data->stdout, 2);
  26         os_close_file(data->stdin);
  27         os_close_file(data->stdout);
  28         os_close_file(data->close_me[0]);
  29         os_close_file(data->close_me[1]);
  30 }
  31
  32 int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
  33 {
  34         struct dog_data data;
  35         int in_fds[2], out_fds[2], pid, n, err;
  36         char pid_buf[sizeof("nnnnn\0")], c;
  37         char *pid_args[] = { "/usr/bin/uml_watchdog", "-pid", pid_buf, NULL };
  38         char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL,
  39                                   NULL };
  40         char **args = NULL;
  41
  42         err = os_pipe(in_fds, 1, 0);
  43         if(err < 0){
  44                 printk("harddog_open - os_pipe failed, err = %d\n", -err);
  45                 goto out;
  46         }
  47
  48         err = os_pipe(out_fds, 1, 0);
  49         if(err < 0){
  50                 printk("harddog_open - os_pipe failed, err = %d\n", -err);
  51                 goto out_close_in;
  52         }
  53
  54         data.stdin = out_fds[0];
  55         data.stdout = in_fds[1];
  56         data.close_me[0] = out_fds[1];
  57         data.close_me[1] = in_fds[0];
  58
  59         if(sock != NULL){
  60                 mconsole_args[2] = sock;
  61                 args = mconsole_args;
  62         }
  63         else {
  64                 /* XXX The os_getpid() is not SMP correct */
  65                 sprintf(pid_buf, "%d", os_getpid());
  66                 args = pid_args;
  67         }
  68
  69         pid = run_helper(pre_exec, &data, args);
  70
  71         os_close_file(out_fds[0]);
  72         os_close_file(in_fds[1]);
  73
  74         if(pid < 0){
  75                 err = -pid;
  76                 printk("harddog_open - run_helper failed, errno = %d\n", -err);
  77                 goto out_close_out;
  78         }
  79
  80         n = os_read_file(in_fds[0], &c, sizeof(c));
  81         if(n == 0){
  82                 printk("harddog_open - EOF on watchdog pipe\n");
  83                 helper_wait(pid);
  84                 err = -EIO;
  85                 goto out_close_out;
  86         }
  87         else if(n < 0){
  88                 printk("harddog_open - read of watchdog pipe failed, "
  89                        "err = %d\n", -n);
  90                 helper_wait(pid);
  91                 err = n;
  92                 goto out_close_out;
  93         }
  94         *in_fd_ret = in_fds[0];
  95         *out_fd_ret = out_fds[1];
  96         return 0;
  97
  98  out_close_in:
  99         os_close_file(in_fds[0]);
 100         os_close_file(in_fds[1]);
 101  out_close_out:
 102         os_close_file(out_fds[0]);
 103         os_close_file(out_fds[1]);
 104  out:
 105         return err;
 106 }
 107
 108 void stop_watchdog(int in_fd, int out_fd)
 109 {
 110         os_close_file(in_fd);
 111         os_close_file(out_fd);
 112 }
 113
 114 int ping_watchdog(int fd)
 115 {
 116         int n;
 117         char c = '\n';
 118
 119         n = os_write_file(fd, &c, sizeof(c));
 120         if(n != sizeof(c)){
 121                 printk("ping_watchdog - write failed, err = %d\n", -n);
 122                 if(n < 0)
 123                         return n;
 124                 return -EIO;
 125         }
 126         return 1;
 127
 128 }