Commit | Line | Data |
---|---|---|
ff5c6ff5 | 1 | /* |
1da177e4 LT |
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> | |
5d48545e | 11 | #include <limits.h> |
1da177e4 LT |
12 | #include <sys/signal.h> |
13 | #include <sys/wait.h> | |
512b6fb1 | 14 | #include <sys/socket.h> |
1da177e4 LT |
15 | #include "user.h" |
16 | #include "kern_util.h" | |
1da177e4 | 17 | #include "os.h" |
5d48545e | 18 | #include "um_malloc.h" |
1ffb9164 | 19 | #include "kern_constants.h" |
1da177e4 LT |
20 | |
21 | struct helper_data { | |
22 | void (*pre_exec)(void*); | |
23 | void *pre_data; | |
24 | char **argv; | |
25 | int fd; | |
5d48545e | 26 | char *buf; |
1da177e4 LT |
27 | }; |
28 | ||
1da177e4 LT |
29 | static int helper_child(void *arg) |
30 | { | |
31 | struct helper_data *data = arg; | |
32 | char **argv = data->argv; | |
33 | int errval; | |
34 | ||
8b028bcd | 35 | if (data->pre_exec != NULL) |
1da177e4 | 36 | (*data->pre_exec)(data->pre_data); |
5d48545e | 37 | errval = execvp_noalloc(data->buf, argv[0], argv); |
ef0470c0 JD |
38 | printk("helper_child - execvp of '%s' failed - errno = %d\n", argv[0], |
39 | -errval); | |
a61f334f | 40 | write(data->fd, &errval, sizeof(errval)); |
ff5c6ff5 | 41 | kill(os_getpid(), SIGKILL); |
8b028bcd | 42 | return 0; |
1da177e4 LT |
43 | } |
44 | ||
45 | /* Returns either the pid of the child process we run or -E* on failure. | |
d9d645f0 PBG |
46 | * XXX The alloc_stack here breaks if this is called in the tracing thread, so |
47 | * we need to receive a preallocated stack (a local buffer is ok). */ | |
c4399016 | 48 | int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv) |
1da177e4 LT |
49 | { |
50 | struct helper_data data; | |
51 | unsigned long stack, sp; | |
52 | int pid, fds[2], ret, n; | |
53 | ||
c4399016 | 54 | stack = alloc_stack(0, __cant_sleep()); |
8b028bcd | 55 | if (stack == 0) |
6b7aaad9 | 56 | return -ENOMEM; |
1da177e4 | 57 | |
512b6fb1 | 58 | ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds); |
8b028bcd | 59 | if (ret < 0) { |
512b6fb1 JD |
60 | ret = -errno; |
61 | printk("run_helper : pipe failed, errno = %d\n", errno); | |
1da177e4 LT |
62 | goto out_free; |
63 | } | |
64 | ||
512b6fb1 | 65 | ret = os_set_exec_close(fds[1]); |
8b028bcd | 66 | if (ret < 0) { |
1da177e4 LT |
67 | printk("run_helper : setting FD_CLOEXEC failed, ret = %d\n", |
68 | -ret); | |
69 | goto out_close; | |
70 | } | |
71 | ||
1ffb9164 | 72 | sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
1da177e4 LT |
73 | data.pre_exec = pre_exec; |
74 | data.pre_data = pre_data; | |
75 | data.argv = argv; | |
76 | data.fd = fds[1]; | |
e4c4bf99 JD |
77 | data.buf = __cant_sleep() ? kmalloc(PATH_MAX, UM_GFP_ATOMIC) : |
78 | kmalloc(PATH_MAX, UM_GFP_KERNEL); | |
4dbed85a | 79 | pid = clone(helper_child, (void *) sp, CLONE_VM, &data); |
8b028bcd | 80 | if (pid < 0) { |
1da177e4 | 81 | ret = -errno; |
b4fd310e | 82 | printk("run_helper : clone failed, errno = %d\n", errno); |
5d48545e | 83 | goto out_free2; |
1da177e4 LT |
84 | } |
85 | ||
ff5c6ff5 | 86 | close(fds[1]); |
1da177e4 LT |
87 | fds[1] = -1; |
88 | ||
ef0470c0 JD |
89 | /* |
90 | * Read the errno value from the child, if the exec failed, or get 0 if | |
91 | * the exec succeeded because the pipe fd was set as close-on-exec. | |
92 | */ | |
a61f334f | 93 | n = read(fds[0], &ret, sizeof(ret)); |
8b028bcd | 94 | if (n == 0) { |
1da177e4 | 95 | ret = pid; |
8b028bcd PBG |
96 | } else { |
97 | if (n < 0) { | |
a61f334f | 98 | n = -errno; |
6b7aaad9 JD |
99 | printk("run_helper : read on pipe failed, ret = %d\n", |
100 | -n); | |
101 | ret = n; | |
102 | kill(pid, SIGKILL); | |
103 | } | |
4dbed85a | 104 | CATCH_EINTR(waitpid(pid, NULL, __WCLONE)); |
1da177e4 LT |
105 | } |
106 | ||
5d48545e PBG |
107 | out_free2: |
108 | kfree(data.buf); | |
1da177e4 LT |
109 | out_close: |
110 | if (fds[1] != -1) | |
ff5c6ff5 JD |
111 | close(fds[1]); |
112 | close(fds[0]); | |
1da177e4 | 113 | out_free: |
c4399016 | 114 | free_stack(stack, 0); |
8b028bcd | 115 | return ret; |
1da177e4 LT |
116 | } |
117 | ||
ff5c6ff5 | 118 | int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, |
c4399016 | 119 | unsigned long *stack_out) |
1da177e4 LT |
120 | { |
121 | unsigned long stack, sp; | |
b4fd310e | 122 | int pid, status, err; |
1da177e4 | 123 | |
c4399016 | 124 | stack = alloc_stack(0, __cant_sleep()); |
8b028bcd PBG |
125 | if (stack == 0) |
126 | return -ENOMEM; | |
1da177e4 | 127 | |
c4399016 | 128 | sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
4dbed85a | 129 | pid = clone(proc, (void *) sp, flags, arg); |
8b028bcd | 130 | if (pid < 0) { |
b4fd310e | 131 | err = -errno; |
ff5c6ff5 | 132 | printk("run_helper_thread : clone failed, errno = %d\n", |
1da177e4 | 133 | errno); |
b4fd310e | 134 | return err; |
1da177e4 | 135 | } |
8b028bcd | 136 | if (stack_out == NULL) { |
4dbed85a | 137 | CATCH_EINTR(pid = waitpid(pid, &status, __WCLONE)); |
8b028bcd | 138 | if (pid < 0) { |
b4fd310e | 139 | err = -errno; |
1da177e4 LT |
140 | printk("run_helper_thread - wait failed, errno = %d\n", |
141 | errno); | |
b4fd310e | 142 | pid = err; |
1da177e4 | 143 | } |
8b028bcd | 144 | if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) |
1da177e4 LT |
145 | printk("run_helper_thread - thread returned status " |
146 | "0x%x\n", status); | |
c4399016 | 147 | free_stack(stack, 0); |
8b028bcd PBG |
148 | } else |
149 | *stack_out = stack; | |
150 | return pid; | |
1da177e4 LT |
151 | } |
152 | ||
4dbed85a | 153 | int helper_wait(int pid, int nohang, char *pname) |
1da177e4 | 154 | { |
4dbed85a SG |
155 | int ret, status; |
156 | int wflags = __WCLONE; | |
1da177e4 | 157 | |
4dbed85a SG |
158 | if (nohang) |
159 | wflags |= WNOHANG; | |
160 | ||
161 | if (!pname) | |
162 | pname = "helper_wait"; | |
163 | ||
164 | CATCH_EINTR(ret = waitpid(pid, &status, wflags)); | |
8b028bcd | 165 | if (ret < 0) { |
4dbed85a SG |
166 | printk(UM_KERN_ERR "%s : waitpid process %d failed, " |
167 | "errno = %d\n", pname, pid, errno); | |
168 | return -errno; | |
169 | } else if (nohang && ret == 0) { | |
170 | printk(UM_KERN_ERR "%s : process %d has not exited\n", | |
171 | pname, pid); | |
172 | return -ECHILD; | |
173 | } else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { | |
174 | printk(UM_KERN_ERR "%s : process %d didn't exit with " | |
175 | "status 0\n", pname, pid); | |
176 | return -ECHILD; | |
177 | } else | |
178 | return 0; | |
1da177e4 | 179 | } |