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> | |
512b6fb1 | 10 | #include <sys/socket.h> |
1aa351a3 JD |
11 | #include <sys/wait.h> |
12 | #include "kern_constants.h" | |
1da177e4 | 13 | #include "kern_util.h" |
1da177e4 | 14 | #include "os.h" |
5d48545e | 15 | #include "um_malloc.h" |
1aa351a3 | 16 | #include "user.h" |
1da177e4 LT |
17 | |
18 | struct helper_data { | |
19 | void (*pre_exec)(void*); | |
20 | void *pre_data; | |
21 | char **argv; | |
22 | int fd; | |
5d48545e | 23 | char *buf; |
1da177e4 LT |
24 | }; |
25 | ||
1da177e4 LT |
26 | static int helper_child(void *arg) |
27 | { | |
28 | struct helper_data *data = arg; | |
29 | char **argv = data->argv; | |
1aa351a3 | 30 | int err; |
1da177e4 | 31 | |
8b028bcd | 32 | if (data->pre_exec != NULL) |
1da177e4 | 33 | (*data->pre_exec)(data->pre_data); |
1aa351a3 JD |
34 | err = execvp_noalloc(data->buf, argv[0], argv); |
35 | ||
36 | /* If the exec succeeds, we don't get here */ | |
37 | write(data->fd, &err, sizeof(err)); | |
38 | ||
8b028bcd | 39 | return 0; |
1da177e4 LT |
40 | } |
41 | ||
1aa351a3 | 42 | /* Returns either the pid of the child process we run or -E* on failure. */ |
c4399016 | 43 | int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv) |
1da177e4 LT |
44 | { |
45 | struct helper_data data; | |
46 | unsigned long stack, sp; | |
47 | int pid, fds[2], ret, n; | |
48 | ||
c4399016 | 49 | stack = alloc_stack(0, __cant_sleep()); |
8b028bcd | 50 | if (stack == 0) |
6b7aaad9 | 51 | return -ENOMEM; |
1da177e4 | 52 | |
512b6fb1 | 53 | ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds); |
8b028bcd | 54 | if (ret < 0) { |
512b6fb1 | 55 | ret = -errno; |
1aa351a3 JD |
56 | printk(UM_KERN_ERR "run_helper : pipe failed, errno = %d\n", |
57 | errno); | |
1da177e4 LT |
58 | goto out_free; |
59 | } | |
60 | ||
512b6fb1 | 61 | ret = os_set_exec_close(fds[1]); |
8b028bcd | 62 | if (ret < 0) { |
1aa351a3 JD |
63 | printk(UM_KERN_ERR "run_helper : setting FD_CLOEXEC failed, " |
64 | "ret = %d\n", -ret); | |
1da177e4 LT |
65 | goto out_close; |
66 | } | |
67 | ||
1ffb9164 | 68 | sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
1da177e4 LT |
69 | data.pre_exec = pre_exec; |
70 | data.pre_data = pre_data; | |
71 | data.argv = argv; | |
72 | data.fd = fds[1]; | |
e4c4bf99 JD |
73 | data.buf = __cant_sleep() ? kmalloc(PATH_MAX, UM_GFP_ATOMIC) : |
74 | kmalloc(PATH_MAX, UM_GFP_KERNEL); | |
4dbed85a | 75 | pid = clone(helper_child, (void *) sp, CLONE_VM, &data); |
8b028bcd | 76 | if (pid < 0) { |
1da177e4 | 77 | ret = -errno; |
1aa351a3 JD |
78 | printk(UM_KERN_ERR "run_helper : clone failed, errno = %d\n", |
79 | errno); | |
5d48545e | 80 | goto out_free2; |
1da177e4 LT |
81 | } |
82 | ||
ff5c6ff5 | 83 | close(fds[1]); |
1da177e4 LT |
84 | fds[1] = -1; |
85 | ||
ef0470c0 JD |
86 | /* |
87 | * Read the errno value from the child, if the exec failed, or get 0 if | |
88 | * the exec succeeded because the pipe fd was set as close-on-exec. | |
89 | */ | |
a61f334f | 90 | n = read(fds[0], &ret, sizeof(ret)); |
8b028bcd | 91 | if (n == 0) { |
1da177e4 | 92 | ret = pid; |
8b028bcd PBG |
93 | } else { |
94 | if (n < 0) { | |
a61f334f | 95 | n = -errno; |
1aa351a3 JD |
96 | printk(UM_KERN_ERR "run_helper : read on pipe failed, " |
97 | "ret = %d\n", -n); | |
6b7aaad9 | 98 | ret = n; |
6b7aaad9 | 99 | } |
4dbed85a | 100 | CATCH_EINTR(waitpid(pid, NULL, __WCLONE)); |
1da177e4 LT |
101 | } |
102 | ||
5d48545e PBG |
103 | out_free2: |
104 | kfree(data.buf); | |
1da177e4 LT |
105 | out_close: |
106 | if (fds[1] != -1) | |
ff5c6ff5 JD |
107 | close(fds[1]); |
108 | close(fds[0]); | |
1da177e4 | 109 | out_free: |
c4399016 | 110 | free_stack(stack, 0); |
8b028bcd | 111 | return ret; |
1da177e4 LT |
112 | } |
113 | ||
ff5c6ff5 | 114 | int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, |
c4399016 | 115 | unsigned long *stack_out) |
1da177e4 LT |
116 | { |
117 | unsigned long stack, sp; | |
b4fd310e | 118 | int pid, status, err; |
1da177e4 | 119 | |
c4399016 | 120 | stack = alloc_stack(0, __cant_sleep()); |
8b028bcd PBG |
121 | if (stack == 0) |
122 | return -ENOMEM; | |
1da177e4 | 123 | |
c4399016 | 124 | sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
4dbed85a | 125 | pid = clone(proc, (void *) sp, flags, arg); |
8b028bcd | 126 | if (pid < 0) { |
b4fd310e | 127 | err = -errno; |
1aa351a3 JD |
128 | printk(UM_KERN_ERR "run_helper_thread : clone failed, " |
129 | "errno = %d\n", errno); | |
b4fd310e | 130 | return err; |
1da177e4 | 131 | } |
8b028bcd | 132 | if (stack_out == NULL) { |
4dbed85a | 133 | CATCH_EINTR(pid = waitpid(pid, &status, __WCLONE)); |
8b028bcd | 134 | if (pid < 0) { |
b4fd310e | 135 | err = -errno; |
1aa351a3 JD |
136 | printk(UM_KERN_ERR "run_helper_thread - wait failed, " |
137 | "errno = %d\n", errno); | |
b4fd310e | 138 | pid = err; |
1da177e4 | 139 | } |
8b028bcd | 140 | if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) |
1aa351a3 JD |
141 | printk(UM_KERN_ERR "run_helper_thread - thread " |
142 | "returned status 0x%x\n", status); | |
c4399016 | 143 | free_stack(stack, 0); |
8b028bcd PBG |
144 | } else |
145 | *stack_out = stack; | |
146 | return pid; | |
1da177e4 LT |
147 | } |
148 | ||
1aa351a3 | 149 | int helper_wait(int pid) |
1da177e4 | 150 | { |
4dbed85a SG |
151 | int ret, status; |
152 | int wflags = __WCLONE; | |
1da177e4 | 153 | |
4dbed85a | 154 | CATCH_EINTR(ret = waitpid(pid, &status, wflags)); |
8b028bcd | 155 | if (ret < 0) { |
1aa351a3 JD |
156 | printk(UM_KERN_ERR "helper_wait : waitpid process %d failed, " |
157 | "errno = %d\n", pid, errno); | |
4dbed85a | 158 | return -errno; |
4dbed85a | 159 | } else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
1aa351a3 JD |
160 | printk(UM_KERN_ERR "helper_wait : process %d exited with " |
161 | "status 0x%x\n", pid, status); | |
4dbed85a SG |
162 | return -ECHILD; |
163 | } else | |
164 | return 0; | |
1da177e4 | 165 | } |