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 PBG |
36 | errval = execvp_noalloc(data->buf, argv[0], argv); |
37 | printk("helper_child - execvp of '%s' failed - errno = %d\n", argv[0], -errval); | |
1da177e4 | 38 | os_write_file(data->fd, &errval, sizeof(errval)); |
ff5c6ff5 | 39 | kill(os_getpid(), SIGKILL); |
8b028bcd | 40 | return 0; |
1da177e4 LT |
41 | } |
42 | ||
43 | /* Returns either the pid of the child process we run or -E* on failure. | |
d9d645f0 PBG |
44 | * XXX The alloc_stack here breaks if this is called in the tracing thread, so |
45 | * we need to receive a preallocated stack (a local buffer is ok). */ | |
1da177e4 LT |
46 | int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv, |
47 | unsigned long *stack_out) | |
48 | { | |
49 | struct helper_data data; | |
50 | unsigned long stack, sp; | |
51 | int pid, fds[2], ret, n; | |
52 | ||
8b028bcd | 53 | if ((stack_out != NULL) && (*stack_out != 0)) |
1da177e4 | 54 | stack = *stack_out; |
8b028bcd PBG |
55 | else |
56 | stack = alloc_stack(0, __cant_sleep()); | |
57 | if (stack == 0) | |
6b7aaad9 | 58 | return -ENOMEM; |
1da177e4 LT |
59 | |
60 | ret = os_pipe(fds, 1, 0); | |
8b028bcd | 61 | if (ret < 0) { |
1da177e4 LT |
62 | printk("run_helper : pipe failed, ret = %d\n", -ret); |
63 | goto out_free; | |
64 | } | |
65 | ||
66 | ret = os_set_exec_close(fds[1], 1); | |
8b028bcd | 67 | if (ret < 0) { |
1da177e4 LT |
68 | printk("run_helper : setting FD_CLOEXEC failed, ret = %d\n", |
69 | -ret); | |
70 | goto out_close; | |
71 | } | |
72 | ||
1ffb9164 | 73 | sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *); |
1da177e4 LT |
74 | data.pre_exec = pre_exec; |
75 | data.pre_data = pre_data; | |
76 | data.argv = argv; | |
77 | data.fd = fds[1]; | |
5d48545e PBG |
78 | data.buf = __cant_sleep() ? um_kmalloc_atomic(PATH_MAX) : |
79 | um_kmalloc(PATH_MAX); | |
1da177e4 | 80 | pid = clone(helper_child, (void *) sp, CLONE_VM | SIGCHLD, &data); |
8b028bcd | 81 | if (pid < 0) { |
1da177e4 | 82 | ret = -errno; |
b4fd310e | 83 | printk("run_helper : clone failed, errno = %d\n", errno); |
5d48545e | 84 | goto out_free2; |
1da177e4 LT |
85 | } |
86 | ||
ff5c6ff5 | 87 | close(fds[1]); |
1da177e4 LT |
88 | fds[1] = -1; |
89 | ||
b1c332c9 PBG |
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. */ | |
1da177e4 | 92 | n = os_read_file(fds[0], &ret, sizeof(ret)); |
8b028bcd | 93 | if (n == 0) { |
1da177e4 | 94 | ret = pid; |
8b028bcd PBG |
95 | } else { |
96 | if (n < 0) { | |
6b7aaad9 JD |
97 | printk("run_helper : read on pipe failed, ret = %d\n", |
98 | -n); | |
99 | ret = n; | |
100 | kill(pid, SIGKILL); | |
101 | } | |
102 | CATCH_EINTR(waitpid(pid, NULL, 0)); | |
1da177e4 LT |
103 | } |
104 | ||
5d48545e PBG |
105 | out_free2: |
106 | kfree(data.buf); | |
1da177e4 LT |
107 | out_close: |
108 | if (fds[1] != -1) | |
ff5c6ff5 JD |
109 | close(fds[1]); |
110 | close(fds[0]); | |
1da177e4 | 111 | out_free: |
d9d645f0 | 112 | if ((stack_out == NULL) || (*stack_out == 0)) |
1da177e4 | 113 | free_stack(stack, 0); |
8b028bcd | 114 | return ret; |
1da177e4 LT |
115 | } |
116 | ||
ff5c6ff5 | 117 | int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, |
1da177e4 LT |
118 | unsigned long *stack_out, int stack_order) |
119 | { | |
120 | unsigned long stack, sp; | |
b4fd310e | 121 | int pid, status, err; |
1da177e4 | 122 | |
b6316293 | 123 | stack = alloc_stack(stack_order, __cant_sleep()); |
8b028bcd PBG |
124 | if (stack == 0) |
125 | return -ENOMEM; | |
1da177e4 | 126 | |
1ffb9164 | 127 | sp = stack + (UM_KERN_PAGE_SIZE << stack_order) - sizeof(void *); |
1da177e4 | 128 | pid = clone(proc, (void *) sp, flags | SIGCHLD, arg); |
8b028bcd | 129 | if (pid < 0) { |
b4fd310e | 130 | err = -errno; |
ff5c6ff5 | 131 | printk("run_helper_thread : clone failed, errno = %d\n", |
1da177e4 | 132 | errno); |
b4fd310e | 133 | return err; |
1da177e4 | 134 | } |
8b028bcd | 135 | if (stack_out == NULL) { |
1da177e4 | 136 | CATCH_EINTR(pid = waitpid(pid, &status, 0)); |
8b028bcd | 137 | if (pid < 0) { |
b4fd310e | 138 | err = -errno; |
1da177e4 LT |
139 | printk("run_helper_thread - wait failed, errno = %d\n", |
140 | errno); | |
b4fd310e | 141 | pid = err; |
1da177e4 | 142 | } |
8b028bcd | 143 | if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) |
1da177e4 LT |
144 | printk("run_helper_thread - thread returned status " |
145 | "0x%x\n", status); | |
146 | free_stack(stack, stack_order); | |
8b028bcd PBG |
147 | } else |
148 | *stack_out = stack; | |
149 | return pid; | |
1da177e4 LT |
150 | } |
151 | ||
0d4579ed | 152 | int helper_wait(int pid) |
1da177e4 LT |
153 | { |
154 | int ret; | |
155 | ||
156 | CATCH_EINTR(ret = waitpid(pid, NULL, WNOHANG)); | |
8b028bcd | 157 | if (ret < 0) { |
b4fd310e | 158 | ret = -errno; |
1da177e4 | 159 | printk("helper_wait : waitpid failed, errno = %d\n", errno); |
1da177e4 | 160 | } |
8b028bcd | 161 | return ret; |
1da177e4 | 162 | } |