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> | |
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); | |
6b7aaad9 | 45 | errval = -errno; |
b1c332c9 | 46 | printk("helper_child - execve of '%s' failed - errno = %d\n", argv[0], errno); |
1da177e4 | 47 | os_write_file(data->fd, &errval, sizeof(errval)); |
ff5c6ff5 | 48 | kill(os_getpid(), SIGKILL); |
1da177e4 LT |
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; | |
b6316293 | 63 | else stack = alloc_stack(0, __cant_sleep()); |
1da177e4 | 64 | if(stack == 0) |
6b7aaad9 | 65 | return -ENOMEM; |
1da177e4 LT |
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){ | |
1da177e4 | 87 | ret = -errno; |
b4fd310e | 88 | printk("run_helper : clone failed, errno = %d\n", errno); |
1da177e4 LT |
89 | goto out_close; |
90 | } | |
91 | ||
ff5c6ff5 | 92 | close(fds[1]); |
1da177e4 LT |
93 | fds[1] = -1; |
94 | ||
b1c332c9 PBG |
95 | /* Read the errno value from the child, if the exec failed, or get 0 if |
96 | * the exec succeeded because the pipe fd was set as close-on-exec. */ | |
1da177e4 | 97 | n = os_read_file(fds[0], &ret, sizeof(ret)); |
6b7aaad9 | 98 | if(n == 0) |
1da177e4 | 99 | ret = pid; |
6b7aaad9 JD |
100 | else { |
101 | if(n < 0){ | |
102 | printk("run_helper : read on pipe failed, ret = %d\n", | |
103 | -n); | |
104 | ret = n; | |
105 | kill(pid, SIGKILL); | |
106 | } | |
107 | CATCH_EINTR(waitpid(pid, NULL, 0)); | |
1da177e4 LT |
108 | } |
109 | ||
110 | out_close: | |
111 | if (fds[1] != -1) | |
ff5c6ff5 JD |
112 | close(fds[1]); |
113 | close(fds[0]); | |
1da177e4 LT |
114 | out_free: |
115 | if(stack_out == NULL) | |
116 | free_stack(stack, 0); | |
117 | else *stack_out = stack; | |
118 | return(ret); | |
119 | } | |
120 | ||
ff5c6ff5 | 121 | int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, |
1da177e4 LT |
122 | unsigned long *stack_out, int stack_order) |
123 | { | |
124 | unsigned long stack, sp; | |
b4fd310e | 125 | int pid, status, err; |
1da177e4 | 126 | |
b6316293 | 127 | stack = alloc_stack(stack_order, __cant_sleep()); |
1da177e4 LT |
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){ | |
b4fd310e | 133 | err = -errno; |
ff5c6ff5 | 134 | printk("run_helper_thread : clone failed, errno = %d\n", |
1da177e4 | 135 | errno); |
b4fd310e | 136 | return err; |
1da177e4 LT |
137 | } |
138 | if(stack_out == NULL){ | |
139 | CATCH_EINTR(pid = waitpid(pid, &status, 0)); | |
140 | if(pid < 0){ | |
b4fd310e | 141 | err = -errno; |
1da177e4 LT |
142 | printk("run_helper_thread - wait failed, errno = %d\n", |
143 | errno); | |
b4fd310e | 144 | pid = err; |
1da177e4 LT |
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 | ||
0d4579ed | 155 | int helper_wait(int pid) |
1da177e4 LT |
156 | { |
157 | int ret; | |
158 | ||
159 | CATCH_EINTR(ret = waitpid(pid, NULL, WNOHANG)); | |
160 | if(ret < 0){ | |
b4fd310e | 161 | ret = -errno; |
1da177e4 | 162 | printk("helper_wait : waitpid failed, errno = %d\n", errno); |
1da177e4 LT |
163 | } |
164 | return(ret); | |
165 | } |