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> | |
14 | #include "user.h" | |
15 | #include "kern_util.h" | |
1da177e4 | 16 | #include "os.h" |
5d48545e | 17 | #include "um_malloc.h" |
1ffb9164 | 18 | #include "kern_constants.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; | |
32 | int errval; | |
33 | ||
8b028bcd | 34 | if (data->pre_exec != NULL) |
1da177e4 | 35 | (*data->pre_exec)(data->pre_data); |
5d48545e | 36 | errval = execvp_noalloc(data->buf, argv[0], argv); |
ef0470c0 JD |
37 | printk("helper_child - execvp of '%s' failed - errno = %d\n", argv[0], |
38 | -errval); | |
1da177e4 | 39 | os_write_file(data->fd, &errval, sizeof(errval)); |
ff5c6ff5 | 40 | kill(os_getpid(), SIGKILL); |
8b028bcd | 41 | return 0; |
1da177e4 LT |
42 | } |
43 | ||
44 | /* Returns either the pid of the child process we run or -E* on failure. | |
d9d645f0 PBG |
45 | * XXX The alloc_stack here breaks if this is called in the tracing thread, so |
46 | * we need to receive a preallocated stack (a local buffer is ok). */ | |
1da177e4 LT |
47 | int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv, |
48 | unsigned long *stack_out) | |
49 | { | |
50 | struct helper_data data; | |
51 | unsigned long stack, sp; | |
52 | int pid, fds[2], ret, n; | |
53 | ||
8b028bcd | 54 | if ((stack_out != NULL) && (*stack_out != 0)) |
1da177e4 | 55 | stack = *stack_out; |
8b028bcd PBG |
56 | else |
57 | stack = alloc_stack(0, __cant_sleep()); | |
58 | if (stack == 0) | |
6b7aaad9 | 59 | return -ENOMEM; |
1da177e4 LT |
60 | |
61 | ret = os_pipe(fds, 1, 0); | |
8b028bcd | 62 | if (ret < 0) { |
1da177e4 LT |
63 | printk("run_helper : pipe failed, ret = %d\n", -ret); |
64 | goto out_free; | |
65 | } | |
66 | ||
67 | ret = os_set_exec_close(fds[1], 1); | |
8b028bcd | 68 | if (ret < 0) { |
1da177e4 LT |
69 | printk("run_helper : setting FD_CLOEXEC failed, ret = %d\n", |
70 | -ret); | |
71 | goto out_close; | |
72 | } | |
73 | ||
1ffb9164 | 74 | sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
1da177e4 LT |
75 | data.pre_exec = pre_exec; |
76 | data.pre_data = pre_data; | |
77 | data.argv = argv; | |
78 | data.fd = fds[1]; | |
5d48545e PBG |
79 | data.buf = __cant_sleep() ? um_kmalloc_atomic(PATH_MAX) : |
80 | um_kmalloc(PATH_MAX); | |
1da177e4 | 81 | pid = clone(helper_child, (void *) sp, CLONE_VM | SIGCHLD, &data); |
8b028bcd | 82 | if (pid < 0) { |
1da177e4 | 83 | ret = -errno; |
b4fd310e | 84 | printk("run_helper : clone failed, errno = %d\n", errno); |
5d48545e | 85 | goto out_free2; |
1da177e4 LT |
86 | } |
87 | ||
ff5c6ff5 | 88 | close(fds[1]); |
1da177e4 LT |
89 | fds[1] = -1; |
90 | ||
ef0470c0 JD |
91 | /* |
92 | * Read the errno value from the child, if the exec failed, or get 0 if | |
93 | * the exec succeeded because the pipe fd was set as close-on-exec. | |
94 | */ | |
1da177e4 | 95 | n = os_read_file(fds[0], &ret, sizeof(ret)); |
8b028bcd | 96 | if (n == 0) { |
1da177e4 | 97 | ret = pid; |
8b028bcd PBG |
98 | } else { |
99 | if (n < 0) { | |
6b7aaad9 JD |
100 | printk("run_helper : read on pipe failed, ret = %d\n", |
101 | -n); | |
102 | ret = n; | |
103 | kill(pid, SIGKILL); | |
104 | } | |
105 | CATCH_EINTR(waitpid(pid, NULL, 0)); | |
1da177e4 LT |
106 | } |
107 | ||
5d48545e PBG |
108 | out_free2: |
109 | kfree(data.buf); | |
1da177e4 LT |
110 | out_close: |
111 | if (fds[1] != -1) | |
ff5c6ff5 JD |
112 | close(fds[1]); |
113 | close(fds[0]); | |
1da177e4 | 114 | out_free: |
d9d645f0 | 115 | if ((stack_out == NULL) || (*stack_out == 0)) |
1da177e4 | 116 | free_stack(stack, 0); |
8b028bcd | 117 | return ret; |
1da177e4 LT |
118 | } |
119 | ||
ff5c6ff5 | 120 | int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, |
1da177e4 LT |
121 | unsigned long *stack_out, int stack_order) |
122 | { | |
123 | unsigned long stack, sp; | |
b4fd310e | 124 | int pid, status, err; |
1da177e4 | 125 | |
b6316293 | 126 | stack = alloc_stack(stack_order, __cant_sleep()); |
8b028bcd PBG |
127 | if (stack == 0) |
128 | return -ENOMEM; | |
1da177e4 | 129 | |
1ffb9164 | 130 | sp = stack + (UM_KERN_PAGE_SIZE << stack_order) - sizeof(void *); |
1da177e4 | 131 | pid = clone(proc, (void *) sp, flags | SIGCHLD, arg); |
8b028bcd | 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 | 137 | } |
8b028bcd | 138 | if (stack_out == NULL) { |
1da177e4 | 139 | CATCH_EINTR(pid = waitpid(pid, &status, 0)); |
8b028bcd | 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 | 145 | } |
8b028bcd | 146 | if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) |
1da177e4 LT |
147 | printk("run_helper_thread - thread returned status " |
148 | "0x%x\n", status); | |
149 | free_stack(stack, stack_order); | |
8b028bcd PBG |
150 | } else |
151 | *stack_out = stack; | |
152 | return pid; | |
1da177e4 LT |
153 | } |
154 | ||
0d4579ed | 155 | int helper_wait(int pid) |
1da177e4 LT |
156 | { |
157 | int ret; | |
158 | ||
159 | CATCH_EINTR(ret = waitpid(pid, NULL, WNOHANG)); | |
8b028bcd | 160 | if (ret < 0) { |
b4fd310e | 161 | ret = -errno; |
1da177e4 | 162 | printk("helper_wait : waitpid failed, errno = %d\n", errno); |
1da177e4 | 163 | } |
8b028bcd | 164 | return ret; |
1da177e4 | 165 | } |