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 #include "harddog.h" 11 12 struct dog_data { 13 int stdin_fd; 14 int stdout_fd; 15 int close_me[2]; 16 }; 17 18 static void pre_exec(void *d) 19 { 20 struct dog_data *data = d; 21 22 dup2(data->stdin_fd, 0); 23 dup2(data->stdout_fd, 1); 24 dup2(data->stdout_fd, 2); 25 close(data->stdin_fd); 26 close(data->stdout_fd); 27 close(data->close_me[0]); 28 close(data->close_me[1]); 29 } 30 31 int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock) 32 { 33 struct dog_data data; 34 int in_fds[2], out_fds[2], pid, n, err; 35 char pid_buf[sizeof("nnnnnnn\0")], c; 36 char *pid_args[] = { "/usr/bin/uml_watchdog", "-pid", pid_buf, NULL }; 37 char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL, 38 NULL }; 39 char **args = NULL; 40 41 err = os_pipe(in_fds, 1, 0); 42 if (err < 0) { 43 printk("harddog_open - os_pipe failed, err = %d\n", -err); 44 goto out; 45 } 46 47 err = os_pipe(out_fds, 1, 0); 48 if (err < 0) { 49 printk("harddog_open - os_pipe failed, err = %d\n", -err); 50 goto out_close_in; 51 } 52 53 data.stdin_fd = out_fds[0]; 54 data.stdout_fd = in_fds[1]; 55 data.close_me[0] = out_fds[1]; 56 data.close_me[1] = in_fds[0]; 57 58 if (sock != NULL) { 59 mconsole_args[2] = sock; 60 args = mconsole_args; 61 } 62 else { 63 /* XXX The os_getpid() is not SMP correct */ 64 sprintf(pid_buf, "%d", os_getpid()); 65 args = pid_args; 66 } 67 68 pid = run_helper(pre_exec, &data, args); 69 70 close(out_fds[0]); 71 close(in_fds[1]); 72 73 if (pid < 0) { 74 err = -pid; 75 printk("harddog_open - run_helper failed, errno = %d\n", -err); 76 goto out_close_out; 77 } 78 79 n = read(in_fds[0], &c, sizeof(c)); 80 if (n == 0) { 81 printk("harddog_open - EOF on watchdog pipe\n"); 82 helper_wait(pid); 83 err = -EIO; 84 goto out_close_out; 85 } 86 else if (n < 0) { 87 printk("harddog_open - read of watchdog pipe failed, " 88 "err = %d\n", errno); 89 helper_wait(pid); 90 err = n; 91 goto out_close_out; 92 } 93 *in_fd_ret = in_fds[0]; 94 *out_fd_ret = out_fds[1]; 95 return 0; 96 97 out_close_in: 98 close(in_fds[0]); 99 close(in_fds[1]); 100 out_close_out: 101 close(out_fds[0]); 102 close(out_fds[1]); 103 out: 104 return err; 105 } 106 107 void stop_watchdog(int in_fd, int out_fd) 108 { 109 close(in_fd); 110 close(out_fd); 111 } 112 113 int ping_watchdog(int fd) 114 { 115 int n; 116 char c = '\n'; 117 118 n = write(fd, &c, sizeof(c)); 119 if (n != sizeof(c)) { 120 printk("ping_watchdog - write failed, ret = %d, err = %d\n", 121 n, errno); 122 if (n < 0) 123 return n; 124 return -EIO; 125 } 126 return 1; 127 128 } 129