Commit | Line | Data |
---|---|---|
ff5c6ff5 | 1 | /* |
1aa351a3 | 2 | * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
3 | * Licensed under the GPL |
4 | */ | |
5 | ||
1da177e4 LT |
6 | #include <stdlib.h> |
7 | #include <unistd.h> | |
8 | #include <errno.h> | |
9 | #include <sched.h> | |
b6d8adf4 | 10 | #include <linux/limits.h> |
512b6fb1 | 11 | #include <sys/socket.h> |
1aa351a3 JD |
12 | #include <sys/wait.h> |
13 | #include "kern_constants.h" | |
1da177e4 | 14 | #include "kern_util.h" |
1da177e4 | 15 | #include "os.h" |
5d48545e | 16 | #include "um_malloc.h" |
1aa351a3 | 17 | #include "user.h" |
297e1b25 | 18 | #include <linux/limits.h> |
1da177e4 LT |
19 | |
20 | struct helper_data { | |
21 | void (*pre_exec)(void*); | |
22 | void *pre_data; | |
23 | char **argv; | |
24 | int fd; | |
5d48545e | 25 | char *buf; |
1da177e4 LT |
26 | }; |
27 | ||
1da177e4 LT |
28 | static int helper_child(void *arg) |
29 | { | |
30 | struct helper_data *data = arg; | |
31 | char **argv = data->argv; | |
1aa351a3 | 32 | int err; |
1da177e4 | 33 | |
8b028bcd | 34 | if (data->pre_exec != NULL) |
1da177e4 | 35 | (*data->pre_exec)(data->pre_data); |
1aa351a3 JD |
36 | err = execvp_noalloc(data->buf, argv[0], argv); |
37 | ||
38 | /* If the exec succeeds, we don't get here */ | |
39 | write(data->fd, &err, sizeof(err)); | |
40 | ||
8b028bcd | 41 | return 0; |
1da177e4 LT |
42 | } |
43 | ||
1aa351a3 | 44 | /* Returns either the pid of the child process we run or -E* on failure. */ |
c4399016 | 45 | int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv) |
1da177e4 LT |
46 | { |
47 | struct helper_data data; | |
48 | unsigned long stack, sp; | |
49 | int pid, fds[2], ret, n; | |
50 | ||
c4399016 | 51 | stack = alloc_stack(0, __cant_sleep()); |
8b028bcd | 52 | if (stack == 0) |
6b7aaad9 | 53 | return -ENOMEM; |
1da177e4 | 54 | |
512b6fb1 | 55 | ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds); |
8b028bcd | 56 | if (ret < 0) { |
512b6fb1 | 57 | ret = -errno; |
1aa351a3 JD |
58 | printk(UM_KERN_ERR "run_helper : pipe failed, errno = %d\n", |
59 | errno); | |
1da177e4 LT |
60 | goto out_free; |
61 | } | |
62 | ||
512b6fb1 | 63 | ret = os_set_exec_close(fds[1]); |
8b028bcd | 64 | if (ret < 0) { |
1aa351a3 JD |
65 | printk(UM_KERN_ERR "run_helper : setting FD_CLOEXEC failed, " |
66 | "ret = %d\n", -ret); | |
1da177e4 LT |
67 | goto out_close; |
68 | } | |
69 | ||
1ffb9164 | 70 | sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
1da177e4 LT |
71 | data.pre_exec = pre_exec; |
72 | data.pre_data = pre_data; | |
73 | data.argv = argv; | |
74 | data.fd = fds[1]; | |
43f5b308 JD |
75 | data.buf = __cant_sleep() ? uml_kmalloc(PATH_MAX, UM_GFP_ATOMIC) : |
76 | uml_kmalloc(PATH_MAX, UM_GFP_KERNEL); | |
4dbed85a | 77 | pid = clone(helper_child, (void *) sp, CLONE_VM, &data); |
8b028bcd | 78 | if (pid < 0) { |
1da177e4 | 79 | ret = -errno; |
1aa351a3 JD |
80 | printk(UM_KERN_ERR "run_helper : clone failed, errno = %d\n", |
81 | errno); | |
5d48545e | 82 | goto out_free2; |
1da177e4 LT |
83 | } |
84 | ||
ff5c6ff5 | 85 | close(fds[1]); |
1da177e4 LT |
86 | fds[1] = -1; |
87 | ||
ef0470c0 JD |
88 | /* |
89 | * Read the errno value from the child, if the exec failed, or get 0 if | |
90 | * the exec succeeded because the pipe fd was set as close-on-exec. | |
91 | */ | |
a61f334f | 92 | n = read(fds[0], &ret, sizeof(ret)); |
8b028bcd | 93 | if (n == 0) { |
1da177e4 | 94 | ret = pid; |
8b028bcd PBG |
95 | } else { |
96 | if (n < 0) { | |
a61f334f | 97 | n = -errno; |
1aa351a3 JD |
98 | printk(UM_KERN_ERR "run_helper : read on pipe failed, " |
99 | "ret = %d\n", -n); | |
6b7aaad9 | 100 | ret = n; |
6b7aaad9 | 101 | } |
4dbed85a | 102 | CATCH_EINTR(waitpid(pid, NULL, __WCLONE)); |
1da177e4 LT |
103 | } |
104 | ||
5d48545e PBG |
105 | out_free2: |
106 | kfree(data.buf); | |
1da177e4 LT |
107 | out_close: |
108 | if (fds[1] != -1) | |
ff5c6ff5 JD |
109 | close(fds[1]); |
110 | close(fds[0]); | |
1da177e4 | 111 | out_free: |
c4399016 | 112 | free_stack(stack, 0); |
8b028bcd | 113 | return ret; |
1da177e4 LT |
114 | } |
115 | ||
ff5c6ff5 | 116 | int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, |
c4399016 | 117 | unsigned long *stack_out) |
1da177e4 LT |
118 | { |
119 | unsigned long stack, sp; | |
b4fd310e | 120 | int pid, status, err; |
1da177e4 | 121 | |
c4399016 | 122 | stack = alloc_stack(0, __cant_sleep()); |
8b028bcd PBG |
123 | if (stack == 0) |
124 | return -ENOMEM; | |
1da177e4 | 125 | |
c4399016 | 126 | sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
4dbed85a | 127 | pid = clone(proc, (void *) sp, flags, arg); |
8b028bcd | 128 | if (pid < 0) { |
b4fd310e | 129 | err = -errno; |
1aa351a3 JD |
130 | printk(UM_KERN_ERR "run_helper_thread : clone failed, " |
131 | "errno = %d\n", errno); | |
b4fd310e | 132 | return err; |
1da177e4 | 133 | } |
8b028bcd | 134 | if (stack_out == NULL) { |
4dbed85a | 135 | CATCH_EINTR(pid = waitpid(pid, &status, __WCLONE)); |
8b028bcd | 136 | if (pid < 0) { |
b4fd310e | 137 | err = -errno; |
1aa351a3 JD |
138 | printk(UM_KERN_ERR "run_helper_thread - wait failed, " |
139 | "errno = %d\n", errno); | |
b4fd310e | 140 | pid = err; |
1da177e4 | 141 | } |
8b028bcd | 142 | if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) |
1aa351a3 JD |
143 | printk(UM_KERN_ERR "run_helper_thread - thread " |
144 | "returned status 0x%x\n", status); | |
c4399016 | 145 | free_stack(stack, 0); |
8b028bcd PBG |
146 | } else |
147 | *stack_out = stack; | |
148 | return pid; | |
1da177e4 LT |
149 | } |
150 | ||
1aa351a3 | 151 | int helper_wait(int pid) |
1da177e4 | 152 | { |
4dbed85a SG |
153 | int ret, status; |
154 | int wflags = __WCLONE; | |
1da177e4 | 155 | |
4dbed85a | 156 | CATCH_EINTR(ret = waitpid(pid, &status, wflags)); |
8b028bcd | 157 | if (ret < 0) { |
1aa351a3 JD |
158 | printk(UM_KERN_ERR "helper_wait : waitpid process %d failed, " |
159 | "errno = %d\n", pid, errno); | |
4dbed85a | 160 | return -errno; |
4dbed85a | 161 | } else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
1aa351a3 JD |
162 | printk(UM_KERN_ERR "helper_wait : process %d exited with " |
163 | "status 0x%x\n", pid, status); | |
4dbed85a SG |
164 | return -ECHILD; |
165 | } else | |
166 | return 0; | |
1da177e4 | 167 | } |