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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 | 12 | #include <sys/wait.h> |
37185b33 AV |
13 | #include <kern_util.h> |
14 | #include <os.h> | |
15 | #include <um_malloc.h> | |
1da177e4 LT |
16 | |
17 | struct helper_data { | |
18 | void (*pre_exec)(void*); | |
19 | void *pre_data; | |
20 | char **argv; | |
21 | int fd; | |
5d48545e | 22 | char *buf; |
1da177e4 LT |
23 | }; |
24 | ||
1da177e4 LT |
25 | static int helper_child(void *arg) |
26 | { | |
27 | struct helper_data *data = arg; | |
28 | char **argv = data->argv; | |
2fdf2130 | 29 | int err, ret; |
1da177e4 | 30 | |
8b028bcd | 31 | if (data->pre_exec != NULL) |
1da177e4 | 32 | (*data->pre_exec)(data->pre_data); |
1aa351a3 JD |
33 | err = execvp_noalloc(data->buf, argv[0], argv); |
34 | ||
35 | /* If the exec succeeds, we don't get here */ | |
2fdf2130 | 36 | CATCH_EINTR(ret = write(data->fd, &err, sizeof(err))); |
1aa351a3 | 37 | |
8b028bcd | 38 | return 0; |
1da177e4 LT |
39 | } |
40 | ||
1aa351a3 | 41 | /* Returns either the pid of the child process we run or -E* on failure. */ |
c4399016 | 42 | int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv) |
1da177e4 LT |
43 | { |
44 | struct helper_data data; | |
45 | unsigned long stack, sp; | |
46 | int pid, fds[2], ret, n; | |
47 | ||
c4399016 | 48 | stack = alloc_stack(0, __cant_sleep()); |
8b028bcd | 49 | if (stack == 0) |
6b7aaad9 | 50 | return -ENOMEM; |
1da177e4 | 51 | |
512b6fb1 | 52 | ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds); |
8b028bcd | 53 | if (ret < 0) { |
512b6fb1 | 54 | ret = -errno; |
1aa351a3 JD |
55 | printk(UM_KERN_ERR "run_helper : pipe failed, errno = %d\n", |
56 | errno); | |
1da177e4 LT |
57 | goto out_free; |
58 | } | |
59 | ||
512b6fb1 | 60 | ret = os_set_exec_close(fds[1]); |
8b028bcd | 61 | if (ret < 0) { |
1aa351a3 JD |
62 | printk(UM_KERN_ERR "run_helper : setting FD_CLOEXEC failed, " |
63 | "ret = %d\n", -ret); | |
1da177e4 LT |
64 | goto out_close; |
65 | } | |
66 | ||
1ffb9164 | 67 | sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
1da177e4 LT |
68 | data.pre_exec = pre_exec; |
69 | data.pre_data = pre_data; | |
70 | data.argv = argv; | |
71 | data.fd = fds[1]; | |
43f5b308 JD |
72 | data.buf = __cant_sleep() ? uml_kmalloc(PATH_MAX, UM_GFP_ATOMIC) : |
73 | uml_kmalloc(PATH_MAX, UM_GFP_KERNEL); | |
4dbed85a | 74 | pid = clone(helper_child, (void *) sp, CLONE_VM, &data); |
8b028bcd | 75 | if (pid < 0) { |
1da177e4 | 76 | ret = -errno; |
1aa351a3 JD |
77 | printk(UM_KERN_ERR "run_helper : clone failed, errno = %d\n", |
78 | errno); | |
5d48545e | 79 | goto out_free2; |
1da177e4 LT |
80 | } |
81 | ||
ff5c6ff5 | 82 | close(fds[1]); |
1da177e4 LT |
83 | fds[1] = -1; |
84 | ||
ef0470c0 JD |
85 | /* |
86 | * Read the errno value from the child, if the exec failed, or get 0 if | |
87 | * the exec succeeded because the pipe fd was set as close-on-exec. | |
88 | */ | |
a61f334f | 89 | n = read(fds[0], &ret, sizeof(ret)); |
8b028bcd | 90 | if (n == 0) { |
1da177e4 | 91 | ret = pid; |
8b028bcd PBG |
92 | } else { |
93 | if (n < 0) { | |
a61f334f | 94 | n = -errno; |
1aa351a3 JD |
95 | printk(UM_KERN_ERR "run_helper : read on pipe failed, " |
96 | "ret = %d\n", -n); | |
6b7aaad9 | 97 | ret = n; |
6b7aaad9 | 98 | } |
6b187337 | 99 | CATCH_EINTR(waitpid(pid, NULL, __WALL)); |
1da177e4 LT |
100 | } |
101 | ||
5d48545e PBG |
102 | out_free2: |
103 | kfree(data.buf); | |
1da177e4 LT |
104 | out_close: |
105 | if (fds[1] != -1) | |
ff5c6ff5 JD |
106 | close(fds[1]); |
107 | close(fds[0]); | |
1da177e4 | 108 | out_free: |
c4399016 | 109 | free_stack(stack, 0); |
8b028bcd | 110 | return ret; |
1da177e4 LT |
111 | } |
112 | ||
ff5c6ff5 | 113 | int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, |
c4399016 | 114 | unsigned long *stack_out) |
1da177e4 LT |
115 | { |
116 | unsigned long stack, sp; | |
b4fd310e | 117 | int pid, status, err; |
1da177e4 | 118 | |
c4399016 | 119 | stack = alloc_stack(0, __cant_sleep()); |
8b028bcd PBG |
120 | if (stack == 0) |
121 | return -ENOMEM; | |
1da177e4 | 122 | |
c4399016 | 123 | sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
4dbed85a | 124 | pid = clone(proc, (void *) sp, flags, arg); |
8b028bcd | 125 | if (pid < 0) { |
b4fd310e | 126 | err = -errno; |
1aa351a3 JD |
127 | printk(UM_KERN_ERR "run_helper_thread : clone failed, " |
128 | "errno = %d\n", errno); | |
b4fd310e | 129 | return err; |
1da177e4 | 130 | } |
8b028bcd | 131 | if (stack_out == NULL) { |
6b187337 | 132 | CATCH_EINTR(pid = waitpid(pid, &status, __WALL)); |
8b028bcd | 133 | if (pid < 0) { |
b4fd310e | 134 | err = -errno; |
1aa351a3 JD |
135 | printk(UM_KERN_ERR "run_helper_thread - wait failed, " |
136 | "errno = %d\n", errno); | |
b4fd310e | 137 | pid = err; |
1da177e4 | 138 | } |
8b028bcd | 139 | if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) |
1aa351a3 JD |
140 | printk(UM_KERN_ERR "run_helper_thread - thread " |
141 | "returned status 0x%x\n", status); | |
c4399016 | 142 | free_stack(stack, 0); |
8b028bcd PBG |
143 | } else |
144 | *stack_out = stack; | |
145 | return pid; | |
1da177e4 LT |
146 | } |
147 | ||
1aa351a3 | 148 | int helper_wait(int pid) |
1da177e4 | 149 | { |
4dbed85a | 150 | int ret, status; |
6b187337 | 151 | int wflags = __WALL; |
1da177e4 | 152 | |
4dbed85a | 153 | CATCH_EINTR(ret = waitpid(pid, &status, wflags)); |
8b028bcd | 154 | if (ret < 0) { |
1aa351a3 JD |
155 | printk(UM_KERN_ERR "helper_wait : waitpid process %d failed, " |
156 | "errno = %d\n", pid, errno); | |
4dbed85a | 157 | return -errno; |
4dbed85a | 158 | } else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
1aa351a3 JD |
159 | printk(UM_KERN_ERR "helper_wait : process %d exited with " |
160 | "status 0x%x\n", pid, status); | |
4dbed85a SG |
161 | return -ECHILD; |
162 | } else | |
163 | return 0; | |
1da177e4 | 164 | } |