Jeff Dike | ff5c6ff | 2005-11-07 00:58:51 -0800 | [diff] [blame] | 1 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * Copyright (C) 2002 Jeff Dike (jdike@karaya.com) |
| 3 | * Licensed under the GPL |
| 4 | */ |
| 5 | |
| 6 | #include <stdio.h> |
| 7 | #include <stdlib.h> |
| 8 | #include <unistd.h> |
| 9 | #include <errno.h> |
| 10 | #include <sched.h> |
| 11 | #include <sys/signal.h> |
| 12 | #include <sys/wait.h> |
| 13 | #include "user.h" |
| 14 | #include "kern_util.h" |
| 15 | #include "user_util.h" |
| 16 | #include "os.h" |
| 17 | |
| 18 | struct helper_data { |
| 19 | void (*pre_exec)(void*); |
| 20 | void *pre_data; |
| 21 | char **argv; |
| 22 | int fd; |
| 23 | }; |
| 24 | |
| 25 | /* Debugging aid, changed only from gdb */ |
| 26 | int helper_pause = 0; |
| 27 | |
| 28 | static void helper_hup(int sig) |
| 29 | { |
| 30 | } |
| 31 | |
| 32 | static int helper_child(void *arg) |
| 33 | { |
| 34 | struct helper_data *data = arg; |
| 35 | char **argv = data->argv; |
| 36 | int errval; |
| 37 | |
| 38 | if(helper_pause){ |
| 39 | signal(SIGHUP, helper_hup); |
| 40 | pause(); |
| 41 | } |
| 42 | if(data->pre_exec != NULL) |
| 43 | (*data->pre_exec)(data->pre_data); |
| 44 | execvp(argv[0], argv); |
| 45 | errval = errno; |
| 46 | printk("execvp of '%s' failed - errno = %d\n", argv[0], errno); |
| 47 | os_write_file(data->fd, &errval, sizeof(errval)); |
Jeff Dike | ff5c6ff | 2005-11-07 00:58:51 -0800 | [diff] [blame] | 48 | kill(os_getpid(), SIGKILL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | return(0); |
| 50 | } |
| 51 | |
| 52 | /* Returns either the pid of the child process we run or -E* on failure. |
| 53 | * XXX The alloc_stack here breaks if this is called in the tracing thread */ |
| 54 | int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv, |
| 55 | unsigned long *stack_out) |
| 56 | { |
| 57 | struct helper_data data; |
| 58 | unsigned long stack, sp; |
| 59 | int pid, fds[2], ret, n; |
| 60 | |
| 61 | if((stack_out != NULL) && (*stack_out != 0)) |
| 62 | stack = *stack_out; |
| 63 | else stack = alloc_stack(0, um_in_interrupt()); |
| 64 | if(stack == 0) |
| 65 | return(-ENOMEM); |
| 66 | |
| 67 | ret = os_pipe(fds, 1, 0); |
| 68 | if(ret < 0){ |
| 69 | printk("run_helper : pipe failed, ret = %d\n", -ret); |
| 70 | goto out_free; |
| 71 | } |
| 72 | |
| 73 | ret = os_set_exec_close(fds[1], 1); |
| 74 | if(ret < 0){ |
| 75 | printk("run_helper : setting FD_CLOEXEC failed, ret = %d\n", |
| 76 | -ret); |
| 77 | goto out_close; |
| 78 | } |
| 79 | |
| 80 | sp = stack + page_size() - sizeof(void *); |
| 81 | data.pre_exec = pre_exec; |
| 82 | data.pre_data = pre_data; |
| 83 | data.argv = argv; |
| 84 | data.fd = fds[1]; |
| 85 | pid = clone(helper_child, (void *) sp, CLONE_VM | SIGCHLD, &data); |
| 86 | if(pid < 0){ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | ret = -errno; |
Jeff Dike | b4fd310 | 2005-09-16 19:27:49 -0700 | [diff] [blame] | 88 | printk("run_helper : clone failed, errno = %d\n", errno); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | goto out_close; |
| 90 | } |
| 91 | |
Jeff Dike | ff5c6ff | 2005-11-07 00:58:51 -0800 | [diff] [blame] | 92 | close(fds[1]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | fds[1] = -1; |
| 94 | |
| 95 | /*Read the errno value from the child.*/ |
| 96 | n = os_read_file(fds[0], &ret, sizeof(ret)); |
| 97 | if(n < 0){ |
| 98 | printk("run_helper : read on pipe failed, ret = %d\n", -n); |
| 99 | ret = n; |
Jeff Dike | ff5c6ff | 2005-11-07 00:58:51 -0800 | [diff] [blame] | 100 | kill(pid, SIGKILL); |
| 101 | CATCH_EINTR(waitpid(pid, NULL, 0)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | } |
| 103 | else if(n != 0){ |
| 104 | CATCH_EINTR(n = waitpid(pid, NULL, 0)); |
| 105 | ret = -errno; |
| 106 | } else { |
| 107 | ret = pid; |
| 108 | } |
| 109 | |
| 110 | out_close: |
| 111 | if (fds[1] != -1) |
Jeff Dike | ff5c6ff | 2005-11-07 00:58:51 -0800 | [diff] [blame] | 112 | close(fds[1]); |
| 113 | close(fds[0]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | out_free: |
| 115 | if(stack_out == NULL) |
| 116 | free_stack(stack, 0); |
| 117 | else *stack_out = stack; |
| 118 | return(ret); |
| 119 | } |
| 120 | |
Jeff Dike | ff5c6ff | 2005-11-07 00:58:51 -0800 | [diff] [blame] | 121 | int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | unsigned long *stack_out, int stack_order) |
| 123 | { |
| 124 | unsigned long stack, sp; |
Jeff Dike | b4fd310 | 2005-09-16 19:27:49 -0700 | [diff] [blame] | 125 | int pid, status, err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | |
| 127 | stack = alloc_stack(stack_order, um_in_interrupt()); |
| 128 | if(stack == 0) return(-ENOMEM); |
| 129 | |
| 130 | sp = stack + (page_size() << stack_order) - sizeof(void *); |
| 131 | pid = clone(proc, (void *) sp, flags | SIGCHLD, arg); |
| 132 | if(pid < 0){ |
Jeff Dike | b4fd310 | 2005-09-16 19:27:49 -0700 | [diff] [blame] | 133 | err = -errno; |
Jeff Dike | ff5c6ff | 2005-11-07 00:58:51 -0800 | [diff] [blame] | 134 | printk("run_helper_thread : clone failed, errno = %d\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | errno); |
Jeff Dike | b4fd310 | 2005-09-16 19:27:49 -0700 | [diff] [blame] | 136 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | } |
| 138 | if(stack_out == NULL){ |
| 139 | CATCH_EINTR(pid = waitpid(pid, &status, 0)); |
| 140 | if(pid < 0){ |
Jeff Dike | b4fd310 | 2005-09-16 19:27:49 -0700 | [diff] [blame] | 141 | err = -errno; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | printk("run_helper_thread - wait failed, errno = %d\n", |
| 143 | errno); |
Jeff Dike | b4fd310 | 2005-09-16 19:27:49 -0700 | [diff] [blame] | 144 | pid = err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | } |
| 146 | if(!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) |
| 147 | printk("run_helper_thread - thread returned status " |
| 148 | "0x%x\n", status); |
| 149 | free_stack(stack, stack_order); |
| 150 | } |
| 151 | else *stack_out = stack; |
| 152 | return(pid); |
| 153 | } |
| 154 | |
Jeff Dike | 0d4579e | 2005-07-27 11:43:33 -0700 | [diff] [blame] | 155 | int helper_wait(int pid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | { |
| 157 | int ret; |
| 158 | |
| 159 | CATCH_EINTR(ret = waitpid(pid, NULL, WNOHANG)); |
| 160 | if(ret < 0){ |
Jeff Dike | b4fd310 | 2005-09-16 19:27:49 -0700 | [diff] [blame] | 161 | ret = -errno; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | printk("helper_wait : waitpid failed, errno = %d\n", errno); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | } |
| 164 | return(ret); |
| 165 | } |