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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | kmod, the new module loader (replaces kerneld) | |
3 | Kirk Petersen | |
4 | ||
5 | Reorganized not to be a daemon by Adam Richter, with guidance | |
6 | from Greg Zornetzer. | |
7 | ||
8 | Modified to avoid chroot and file sharing problems. | |
9 | Mikael Pettersson | |
10 | ||
11 | Limit the concurrent number of kmod modprobes to catch loops from | |
12 | "modprobe needs a service that is in a module". | |
13 | Keith Owens <kaos@ocs.com.au> December 1999 | |
14 | ||
15 | Unblock all signals when we exec a usermode process. | |
16 | Shuu Yamaguchi <shuu@wondernetworkresources.com> December 2000 | |
17 | ||
18 | call_usermodehelper wait flag, and remove exec_usermodehelper. | |
19 | Rusty Russell <rusty@rustcorp.com.au> Jan 2003 | |
20 | */ | |
1da177e4 LT |
21 | #include <linux/module.h> |
22 | #include <linux/sched.h> | |
23 | #include <linux/syscalls.h> | |
24 | #include <linux/unistd.h> | |
25 | #include <linux/kmod.h> | |
1da177e4 | 26 | #include <linux/slab.h> |
1da177e4 LT |
27 | #include <linux/completion.h> |
28 | #include <linux/file.h> | |
9f3acc31 | 29 | #include <linux/fdtable.h> |
1da177e4 LT |
30 | #include <linux/workqueue.h> |
31 | #include <linux/security.h> | |
32 | #include <linux/mount.h> | |
33 | #include <linux/kernel.h> | |
34 | #include <linux/init.h> | |
d025c9db | 35 | #include <linux/resource.h> |
8cdd4936 RW |
36 | #include <linux/notifier.h> |
37 | #include <linux/suspend.h> | |
1da177e4 LT |
38 | #include <asm/uaccess.h> |
39 | ||
40 | extern int max_threads; | |
41 | ||
42 | static struct workqueue_struct *khelper_wq; | |
43 | ||
a1ef5adb | 44 | #ifdef CONFIG_MODULES |
1da177e4 LT |
45 | |
46 | /* | |
47 | modprobe_path is set via /proc/sys. | |
48 | */ | |
49 | char modprobe_path[KMOD_PATH_LEN] = "/sbin/modprobe"; | |
50 | ||
51 | /** | |
acae0515 AV |
52 | * __request_module - try to load a kernel module |
53 | * @wait: wait (or not) for the operation to complete | |
bd4207c9 RD |
54 | * @fmt: printf style format string for the name of the module |
55 | * @...: arguments as specified in the format string | |
1da177e4 LT |
56 | * |
57 | * Load a module using the user mode module loader. The function returns | |
58 | * zero on success or a negative errno code on failure. Note that a | |
59 | * successful module load does not mean the module did not then unload | |
60 | * and exit on an error of its own. Callers must check that the service | |
61 | * they requested is now available not blindly invoke it. | |
62 | * | |
63 | * If module auto-loading support is disabled then this function | |
64 | * becomes a no-operation. | |
65 | */ | |
acae0515 | 66 | int __request_module(bool wait, const char *fmt, ...) |
1da177e4 LT |
67 | { |
68 | va_list args; | |
69 | char module_name[MODULE_NAME_LEN]; | |
70 | unsigned int max_modprobes; | |
71 | int ret; | |
72 | char *argv[] = { modprobe_path, "-q", "--", module_name, NULL }; | |
73 | static char *envp[] = { "HOME=/", | |
74 | "TERM=linux", | |
75 | "PATH=/sbin:/usr/sbin:/bin:/usr/bin", | |
76 | NULL }; | |
77 | static atomic_t kmod_concurrent = ATOMIC_INIT(0); | |
78 | #define MAX_KMOD_CONCURRENT 50 /* Completely arbitrary value - KAO */ | |
79 | static int kmod_loop_msg; | |
80 | ||
81 | va_start(args, fmt); | |
82 | ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args); | |
83 | va_end(args); | |
84 | if (ret >= MODULE_NAME_LEN) | |
85 | return -ENAMETOOLONG; | |
86 | ||
87 | /* If modprobe needs a service that is in a module, we get a recursive | |
88 | * loop. Limit the number of running kmod threads to max_threads/2 or | |
89 | * MAX_KMOD_CONCURRENT, whichever is the smaller. A cleaner method | |
90 | * would be to run the parents of this process, counting how many times | |
91 | * kmod was invoked. That would mean accessing the internals of the | |
92 | * process tables to get the command line, proc_pid_cmdline is static | |
93 | * and it is not worth changing the proc code just to handle this case. | |
94 | * KAO. | |
95 | * | |
96 | * "trace the ppid" is simple, but will fail if someone's | |
97 | * parent exits. I think this is as good as it gets. --RR | |
98 | */ | |
99 | max_modprobes = min(max_threads/2, MAX_KMOD_CONCURRENT); | |
100 | atomic_inc(&kmod_concurrent); | |
101 | if (atomic_read(&kmod_concurrent) > max_modprobes) { | |
102 | /* We may be blaming an innocent here, but unlikely */ | |
103 | if (kmod_loop_msg++ < 5) | |
104 | printk(KERN_ERR | |
105 | "request_module: runaway loop modprobe %s\n", | |
106 | module_name); | |
107 | atomic_dec(&kmod_concurrent); | |
108 | return -ENOMEM; | |
109 | } | |
110 | ||
acae0515 AV |
111 | ret = call_usermodehelper(modprobe_path, argv, envp, |
112 | wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC); | |
1da177e4 LT |
113 | atomic_dec(&kmod_concurrent); |
114 | return ret; | |
115 | } | |
acae0515 | 116 | EXPORT_SYMBOL(__request_module); |
118a9069 | 117 | #endif /* CONFIG_MODULES */ |
1da177e4 LT |
118 | |
119 | struct subprocess_info { | |
65f27f38 | 120 | struct work_struct work; |
1da177e4 | 121 | struct completion *complete; |
d84f4f99 | 122 | struct cred *cred; |
1da177e4 LT |
123 | char *path; |
124 | char **argv; | |
125 | char **envp; | |
86313c48 | 126 | enum umh_wait wait; |
1da177e4 | 127 | int retval; |
e239ca54 | 128 | struct file *stdin; |
0ab4dc92 | 129 | void (*cleanup)(char **argv, char **envp); |
1da177e4 LT |
130 | }; |
131 | ||
132 | /* | |
133 | * This is the task which runs the usermode application | |
134 | */ | |
135 | static int ____call_usermodehelper(void *data) | |
136 | { | |
137 | struct subprocess_info *sub_info = data; | |
138 | int retval; | |
139 | ||
d84f4f99 DH |
140 | BUG_ON(atomic_read(&sub_info->cred->usage) != 1); |
141 | ||
142 | /* Unblock all signals */ | |
1da177e4 LT |
143 | spin_lock_irq(¤t->sighand->siglock); |
144 | flush_signal_handlers(current, 1); | |
145 | sigemptyset(¤t->blocked); | |
146 | recalc_sigpending(); | |
147 | spin_unlock_irq(¤t->sighand->siglock); | |
148 | ||
d84f4f99 DH |
149 | /* Install the credentials */ |
150 | commit_creds(sub_info->cred); | |
151 | sub_info->cred = NULL; | |
7888e7ff | 152 | |
e239ca54 AK |
153 | /* Install input pipe when needed */ |
154 | if (sub_info->stdin) { | |
155 | struct files_struct *f = current->files; | |
156 | struct fdtable *fdt; | |
157 | /* no races because files should be private here */ | |
158 | sys_close(0); | |
159 | fd_install(0, sub_info->stdin); | |
160 | spin_lock(&f->file_lock); | |
161 | fdt = files_fdtable(f); | |
162 | FD_SET(0, fdt->open_fds); | |
163 | FD_CLR(0, fdt->close_on_exec); | |
164 | spin_unlock(&f->file_lock); | |
d025c9db AK |
165 | |
166 | /* and disallow core files too */ | |
167 | current->signal->rlim[RLIMIT_CORE] = (struct rlimit){0, 0}; | |
e239ca54 AK |
168 | } |
169 | ||
1da177e4 | 170 | /* We can run anywhere, unlike our parent keventd(). */ |
1a2142af | 171 | set_cpus_allowed_ptr(current, cpu_all_mask); |
1da177e4 | 172 | |
b73a7e76 JE |
173 | /* |
174 | * Our parent is keventd, which runs with elevated scheduling priority. | |
175 | * Avoid propagating that into the userspace child. | |
176 | */ | |
177 | set_user_nice(current, 0); | |
178 | ||
db74ece9 | 179 | retval = kernel_execve(sub_info->path, sub_info->argv, sub_info->envp); |
1da177e4 LT |
180 | |
181 | /* Exec failed? */ | |
182 | sub_info->retval = retval; | |
183 | do_exit(0); | |
184 | } | |
185 | ||
0ab4dc92 JF |
186 | void call_usermodehelper_freeinfo(struct subprocess_info *info) |
187 | { | |
188 | if (info->cleanup) | |
189 | (*info->cleanup)(info->argv, info->envp); | |
d84f4f99 DH |
190 | if (info->cred) |
191 | put_cred(info->cred); | |
0ab4dc92 JF |
192 | kfree(info); |
193 | } | |
194 | EXPORT_SYMBOL(call_usermodehelper_freeinfo); | |
195 | ||
1da177e4 LT |
196 | /* Keventd can't block, but this (a child) can. */ |
197 | static int wait_for_helper(void *data) | |
198 | { | |
199 | struct subprocess_info *sub_info = data; | |
200 | pid_t pid; | |
1da177e4 LT |
201 | |
202 | /* Install a handler: if SIGCLD isn't handled sys_wait4 won't | |
203 | * populate the status, but will return -ECHILD. */ | |
1da177e4 LT |
204 | allow_signal(SIGCHLD); |
205 | ||
206 | pid = kernel_thread(____call_usermodehelper, sub_info, SIGCHLD); | |
207 | if (pid < 0) { | |
208 | sub_info->retval = pid; | |
209 | } else { | |
111dbe0c BS |
210 | int ret; |
211 | ||
1da177e4 LT |
212 | /* |
213 | * Normally it is bogus to call wait4() from in-kernel because | |
214 | * wait4() wants to write the exit code to a userspace address. | |
215 | * But wait_for_helper() always runs as keventd, and put_user() | |
216 | * to a kernel address works OK for kernel threads, due to their | |
217 | * having an mm_segment_t which spans the entire address space. | |
218 | * | |
219 | * Thus the __user pointer cast is valid here. | |
220 | */ | |
111dbe0c BS |
221 | sys_wait4(pid, (int __user *)&ret, 0, NULL); |
222 | ||
223 | /* | |
224 | * If ret is 0, either ____call_usermodehelper failed and the | |
225 | * real error code is already in sub_info->retval or | |
226 | * sub_info->retval is 0 anyway, so don't mess with it then. | |
227 | */ | |
228 | if (ret) | |
229 | sub_info->retval = ret; | |
1da177e4 LT |
230 | } |
231 | ||
86313c48 | 232 | if (sub_info->wait == UMH_NO_WAIT) |
0ab4dc92 | 233 | call_usermodehelper_freeinfo(sub_info); |
a98f0dd3 AK |
234 | else |
235 | complete(sub_info->complete); | |
1da177e4 LT |
236 | return 0; |
237 | } | |
238 | ||
239 | /* This is run by khelper thread */ | |
65f27f38 | 240 | static void __call_usermodehelper(struct work_struct *work) |
1da177e4 | 241 | { |
65f27f38 DH |
242 | struct subprocess_info *sub_info = |
243 | container_of(work, struct subprocess_info, work); | |
1da177e4 | 244 | pid_t pid; |
86313c48 | 245 | enum umh_wait wait = sub_info->wait; |
1da177e4 | 246 | |
d84f4f99 DH |
247 | BUG_ON(atomic_read(&sub_info->cred->usage) != 1); |
248 | ||
1da177e4 LT |
249 | /* CLONE_VFORK: wait until the usermode helper has execve'd |
250 | * successfully We need the data structures to stay around | |
251 | * until that is done. */ | |
86313c48 | 252 | if (wait == UMH_WAIT_PROC || wait == UMH_NO_WAIT) |
1da177e4 LT |
253 | pid = kernel_thread(wait_for_helper, sub_info, |
254 | CLONE_FS | CLONE_FILES | SIGCHLD); | |
255 | else | |
256 | pid = kernel_thread(____call_usermodehelper, sub_info, | |
257 | CLONE_VFORK | SIGCHLD); | |
258 | ||
86313c48 JF |
259 | switch (wait) { |
260 | case UMH_NO_WAIT: | |
261 | break; | |
a98f0dd3 | 262 | |
86313c48 JF |
263 | case UMH_WAIT_PROC: |
264 | if (pid > 0) | |
265 | break; | |
1da177e4 | 266 | sub_info->retval = pid; |
86313c48 JF |
267 | /* FALLTHROUGH */ |
268 | ||
269 | case UMH_WAIT_EXEC: | |
1da177e4 | 270 | complete(sub_info->complete); |
86313c48 | 271 | } |
1da177e4 LT |
272 | } |
273 | ||
1bfcf130 | 274 | #ifdef CONFIG_PM_SLEEP |
ccd4b65a RW |
275 | /* |
276 | * If set, call_usermodehelper_exec() will exit immediately returning -EBUSY | |
277 | * (used for preventing user land processes from being created after the user | |
278 | * land has been frozen during a system-wide hibernation or suspend operation). | |
279 | */ | |
280 | static int usermodehelper_disabled; | |
281 | ||
282 | /* Number of helpers running */ | |
283 | static atomic_t running_helpers = ATOMIC_INIT(0); | |
284 | ||
285 | /* | |
286 | * Wait queue head used by usermodehelper_pm_callback() to wait for all running | |
287 | * helpers to finish. | |
288 | */ | |
289 | static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq); | |
290 | ||
291 | /* | |
292 | * Time to wait for running_helpers to become zero before the setting of | |
293 | * usermodehelper_disabled in usermodehelper_pm_callback() fails | |
294 | */ | |
295 | #define RUNNING_HELPERS_TIMEOUT (5 * HZ) | |
296 | ||
1bfcf130 RW |
297 | /** |
298 | * usermodehelper_disable - prevent new helpers from being started | |
299 | */ | |
300 | int usermodehelper_disable(void) | |
8cdd4936 | 301 | { |
ccd4b65a RW |
302 | long retval; |
303 | ||
1bfcf130 RW |
304 | usermodehelper_disabled = 1; |
305 | smp_mb(); | |
306 | /* | |
307 | * From now on call_usermodehelper_exec() won't start any new | |
308 | * helpers, so it is sufficient if running_helpers turns out to | |
309 | * be zero at one point (it may be increased later, but that | |
310 | * doesn't matter). | |
311 | */ | |
312 | retval = wait_event_timeout(running_helpers_waitq, | |
ccd4b65a RW |
313 | atomic_read(&running_helpers) == 0, |
314 | RUNNING_HELPERS_TIMEOUT); | |
1bfcf130 RW |
315 | if (retval) |
316 | return 0; | |
8cdd4936 | 317 | |
1bfcf130 RW |
318 | usermodehelper_disabled = 0; |
319 | return -EAGAIN; | |
320 | } | |
321 | ||
322 | /** | |
323 | * usermodehelper_enable - allow new helpers to be started again | |
324 | */ | |
325 | void usermodehelper_enable(void) | |
326 | { | |
327 | usermodehelper_disabled = 0; | |
8cdd4936 RW |
328 | } |
329 | ||
ccd4b65a RW |
330 | static void helper_lock(void) |
331 | { | |
332 | atomic_inc(&running_helpers); | |
333 | smp_mb__after_atomic_inc(); | |
334 | } | |
335 | ||
336 | static void helper_unlock(void) | |
337 | { | |
338 | if (atomic_dec_and_test(&running_helpers)) | |
339 | wake_up(&running_helpers_waitq); | |
340 | } | |
1bfcf130 | 341 | #else /* CONFIG_PM_SLEEP */ |
ccd4b65a RW |
342 | #define usermodehelper_disabled 0 |
343 | ||
344 | static inline void helper_lock(void) {} | |
345 | static inline void helper_unlock(void) {} | |
1bfcf130 | 346 | #endif /* CONFIG_PM_SLEEP */ |
ccd4b65a | 347 | |
1da177e4 | 348 | /** |
0ab4dc92 | 349 | * call_usermodehelper_setup - prepare to call a usermode helper |
61df47c8 RD |
350 | * @path: path to usermode executable |
351 | * @argv: arg vector for process | |
352 | * @envp: environment for process | |
ac331d15 | 353 | * @gfp_mask: gfp mask for memory allocation |
0ab4dc92 | 354 | * |
61df47c8 | 355 | * Returns either %NULL on allocation failure, or a subprocess_info |
0ab4dc92 JF |
356 | * structure. This should be passed to call_usermodehelper_exec to |
357 | * exec the process and free the structure. | |
358 | */ | |
ac331d15 KM |
359 | struct subprocess_info *call_usermodehelper_setup(char *path, char **argv, |
360 | char **envp, gfp_t gfp_mask) | |
0ab4dc92 JF |
361 | { |
362 | struct subprocess_info *sub_info; | |
ac331d15 | 363 | sub_info = kzalloc(sizeof(struct subprocess_info), gfp_mask); |
0ab4dc92 JF |
364 | if (!sub_info) |
365 | goto out; | |
366 | ||
367 | INIT_WORK(&sub_info->work, __call_usermodehelper); | |
368 | sub_info->path = path; | |
369 | sub_info->argv = argv; | |
370 | sub_info->envp = envp; | |
d84f4f99 | 371 | sub_info->cred = prepare_usermodehelper_creds(); |
ab2b7eba TH |
372 | if (!sub_info->cred) { |
373 | kfree(sub_info); | |
d84f4f99 | 374 | return NULL; |
ab2b7eba | 375 | } |
0ab4dc92 JF |
376 | |
377 | out: | |
378 | return sub_info; | |
379 | } | |
380 | EXPORT_SYMBOL(call_usermodehelper_setup); | |
381 | ||
382 | /** | |
383 | * call_usermodehelper_setkeys - set the session keys for usermode helper | |
384 | * @info: a subprocess_info returned by call_usermodehelper_setup | |
385 | * @session_keyring: the session keyring for the process | |
386 | */ | |
387 | void call_usermodehelper_setkeys(struct subprocess_info *info, | |
388 | struct key *session_keyring) | |
389 | { | |
d84f4f99 DH |
390 | #ifdef CONFIG_KEYS |
391 | struct thread_group_cred *tgcred = info->cred->tgcred; | |
392 | key_put(tgcred->session_keyring); | |
393 | tgcred->session_keyring = key_get(session_keyring); | |
394 | #else | |
395 | BUG(); | |
396 | #endif | |
0ab4dc92 JF |
397 | } |
398 | EXPORT_SYMBOL(call_usermodehelper_setkeys); | |
399 | ||
400 | /** | |
401 | * call_usermodehelper_setcleanup - set a cleanup function | |
402 | * @info: a subprocess_info returned by call_usermodehelper_setup | |
403 | * @cleanup: a cleanup function | |
404 | * | |
405 | * The cleanup function is just befor ethe subprocess_info is about to | |
406 | * be freed. This can be used for freeing the argv and envp. The | |
407 | * Function must be runnable in either a process context or the | |
408 | * context in which call_usermodehelper_exec is called. | |
409 | */ | |
410 | void call_usermodehelper_setcleanup(struct subprocess_info *info, | |
411 | void (*cleanup)(char **argv, char **envp)) | |
412 | { | |
413 | info->cleanup = cleanup; | |
414 | } | |
415 | EXPORT_SYMBOL(call_usermodehelper_setcleanup); | |
416 | ||
417 | /** | |
418 | * call_usermodehelper_stdinpipe - set up a pipe to be used for stdin | |
419 | * @sub_info: a subprocess_info returned by call_usermodehelper_setup | |
420 | * @filp: set to the write-end of a pipe | |
421 | * | |
422 | * This constructs a pipe, and sets the read end to be the stdin of the | |
423 | * subprocess, and returns the write-end in *@filp. | |
424 | */ | |
425 | int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info, | |
426 | struct file **filp) | |
427 | { | |
428 | struct file *f; | |
429 | ||
be61a86d | 430 | f = create_write_pipe(0); |
0ab4dc92 JF |
431 | if (IS_ERR(f)) |
432 | return PTR_ERR(f); | |
433 | *filp = f; | |
434 | ||
be61a86d | 435 | f = create_read_pipe(f, 0); |
0ab4dc92 JF |
436 | if (IS_ERR(f)) { |
437 | free_write_pipe(*filp); | |
438 | return PTR_ERR(f); | |
439 | } | |
440 | sub_info->stdin = f; | |
441 | ||
442 | return 0; | |
443 | } | |
444 | EXPORT_SYMBOL(call_usermodehelper_stdinpipe); | |
445 | ||
446 | /** | |
447 | * call_usermodehelper_exec - start a usermode application | |
448 | * @sub_info: information about the subprocessa | |
1da177e4 | 449 | * @wait: wait for the application to finish and return status. |
a98f0dd3 AK |
450 | * when -1 don't wait at all, but you get no useful error back when |
451 | * the program couldn't be exec'ed. This makes it safe to call | |
452 | * from interrupt context. | |
1da177e4 LT |
453 | * |
454 | * Runs a user-space application. The application is started | |
455 | * asynchronously if wait is not set, and runs as a child of keventd. | |
456 | * (ie. it runs with full root capabilities). | |
1da177e4 | 457 | */ |
0ab4dc92 | 458 | int call_usermodehelper_exec(struct subprocess_info *sub_info, |
86313c48 | 459 | enum umh_wait wait) |
1da177e4 | 460 | { |
60be6b9a | 461 | DECLARE_COMPLETION_ONSTACK(done); |
78468033 | 462 | int retval = 0; |
1da177e4 | 463 | |
d84f4f99 DH |
464 | BUG_ON(atomic_read(&sub_info->cred->usage) != 1); |
465 | ||
ccd4b65a | 466 | helper_lock(); |
78468033 | 467 | if (sub_info->path[0] == '\0') |
0ab4dc92 | 468 | goto out; |
1da177e4 | 469 | |
8cdd4936 | 470 | if (!khelper_wq || usermodehelper_disabled) { |
0ab4dc92 JF |
471 | retval = -EBUSY; |
472 | goto out; | |
473 | } | |
a98f0dd3 | 474 | |
a98f0dd3 | 475 | sub_info->complete = &done; |
a98f0dd3 AK |
476 | sub_info->wait = wait; |
477 | ||
478 | queue_work(khelper_wq, &sub_info->work); | |
78468033 NC |
479 | if (wait == UMH_NO_WAIT) /* task has freed sub_info */ |
480 | goto unlock; | |
1da177e4 | 481 | wait_for_completion(&done); |
a98f0dd3 | 482 | retval = sub_info->retval; |
0ab4dc92 | 483 | |
78468033 | 484 | out: |
0ab4dc92 | 485 | call_usermodehelper_freeinfo(sub_info); |
78468033 | 486 | unlock: |
ccd4b65a | 487 | helper_unlock(); |
a98f0dd3 | 488 | return retval; |
1da177e4 | 489 | } |
0ab4dc92 | 490 | EXPORT_SYMBOL(call_usermodehelper_exec); |
1da177e4 | 491 | |
0ab4dc92 JF |
492 | /** |
493 | * call_usermodehelper_pipe - call a usermode helper process with a pipe stdin | |
494 | * @path: path to usermode executable | |
495 | * @argv: arg vector for process | |
496 | * @envp: environment for process | |
497 | * @filp: set to the write-end of a pipe | |
498 | * | |
499 | * This is a simple wrapper which executes a usermode-helper function | |
500 | * with a pipe as stdin. It is implemented entirely in terms of | |
501 | * lower-level call_usermodehelper_* functions. | |
502 | */ | |
e239ca54 AK |
503 | int call_usermodehelper_pipe(char *path, char **argv, char **envp, |
504 | struct file **filp) | |
505 | { | |
0ab4dc92 JF |
506 | struct subprocess_info *sub_info; |
507 | int ret; | |
e239ca54 | 508 | |
ac331d15 | 509 | sub_info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL); |
0ab4dc92 JF |
510 | if (sub_info == NULL) |
511 | return -ENOMEM; | |
e239ca54 | 512 | |
0ab4dc92 JF |
513 | ret = call_usermodehelper_stdinpipe(sub_info, filp); |
514 | if (ret < 0) | |
515 | goto out; | |
e239ca54 | 516 | |
3210f0ec | 517 | return call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC); |
e239ca54 | 518 | |
0ab4dc92 JF |
519 | out: |
520 | call_usermodehelper_freeinfo(sub_info); | |
521 | return ret; | |
e239ca54 AK |
522 | } |
523 | EXPORT_SYMBOL(call_usermodehelper_pipe); | |
524 | ||
1da177e4 LT |
525 | void __init usermodehelper_init(void) |
526 | { | |
527 | khelper_wq = create_singlethread_workqueue("khelper"); | |
528 | BUG_ON(!khelper_wq); | |
529 | } |