| /* |
| kmod, the new module loader (replaces kerneld) |
| Kirk Petersen |
| |
| Reorganized not to be a daemon by Adam Richter, with guidance |
| from Greg Zornetzer. |
| |
| Modified to avoid chroot and file sharing problems. |
| Mikael Pettersson |
| |
| Limit the concurrent number of kmod modprobes to catch loops from |
| "modprobe needs a service that is in a module". |
| Keith Owens <kaos@ocs.com.au> December 1999 |
| |
| Unblock all signals when we exec a usermode process. |
| Shuu Yamaguchi <shuu@wondernetworkresources.com> December 2000 |
| |
| call_usermodehelper wait flag, and remove exec_usermodehelper. |
| Rusty Russell <rusty@rustcorp.com.au> Jan 2003 |
| */ |
| #include <linux/module.h> |
| #include <linux/sched.h> |
| #include <linux/syscalls.h> |
| #include <linux/unistd.h> |
| #include <linux/kmod.h> |
| #include <linux/slab.h> |
| #include <linux/completion.h> |
| #include <linux/cred.h> |
| #include <linux/file.h> |
| #include <linux/fdtable.h> |
| #include <linux/workqueue.h> |
| #include <linux/security.h> |
| #include <linux/mount.h> |
| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/resource.h> |
| #include <linux/notifier.h> |
| #include <linux/suspend.h> |
| #include <linux/rwsem.h> |
| #include <linux/ptrace.h> |
| #include <linux/async.h> |
| #include <asm/uaccess.h> |
| |
| #include <trace/events/module.h> |
| |
| extern int max_threads; |
| |
| static struct workqueue_struct *khelper_wq; |
| |
| /* |
| * kmod_thread_locker is used for deadlock avoidance. There is no explicit |
| * locking to protect this global - it is private to the singleton khelper |
| * thread and should only ever be modified by that thread. |
| */ |
| static const struct task_struct *kmod_thread_locker; |
| |
| #define CAP_BSET (void *)1 |
| #define CAP_PI (void *)2 |
| |
| static kernel_cap_t usermodehelper_bset = CAP_FULL_SET; |
| static kernel_cap_t usermodehelper_inheritable = CAP_FULL_SET; |
| static DEFINE_SPINLOCK(umh_sysctl_lock); |
| static DECLARE_RWSEM(umhelper_sem); |
| |
| #ifdef CONFIG_MODULES |
| |
| /* |
| modprobe_path is set via /proc/sys. |
| */ |
| char modprobe_path[KMOD_PATH_LEN] = "/sbin/modprobe"; |
| |
| static void free_modprobe_argv(struct subprocess_info *info) |
| { |
| kfree(info->argv[3]); /* check call_modprobe() */ |
| kfree(info->argv); |
| } |
| |
| static int call_modprobe(char *module_name, int wait) |
| { |
| struct subprocess_info *info; |
| static char *envp[] = { |
| "HOME=/", |
| "TERM=linux", |
| "PATH=/sbin:/usr/sbin:/bin:/usr/bin", |
| NULL |
| }; |
| |
| char **argv = kmalloc(sizeof(char *[5]), GFP_KERNEL); |
| if (!argv) |
| goto out; |
| |
| module_name = kstrdup(module_name, GFP_KERNEL); |
| if (!module_name) |
| goto free_argv; |
| |
| argv[0] = modprobe_path; |
| argv[1] = "-q"; |
| argv[2] = "--"; |
| argv[3] = module_name; /* check free_modprobe_argv() */ |
| argv[4] = NULL; |
| |
| info = call_usermodehelper_setup(modprobe_path, argv, envp, GFP_KERNEL, |
| NULL, free_modprobe_argv, NULL); |
| if (!info) |
| goto free_module_name; |
| |
| return call_usermodehelper_exec(info, wait | UMH_KILLABLE); |
| |
| free_module_name: |
| kfree(module_name); |
| free_argv: |
| kfree(argv); |
| out: |
| return -ENOMEM; |
| } |
| |
| /** |
| * __request_module - try to load a kernel module |
| * @wait: wait (or not) for the operation to complete |
| * @fmt: printf style format string for the name of the module |
| * @...: arguments as specified in the format string |
| * |
| * Load a module using the user mode module loader. The function returns |
| * zero on success or a negative errno code on failure. Note that a |
| * successful module load does not mean the module did not then unload |
| * and exit on an error of its own. Callers must check that the service |
| * they requested is now available not blindly invoke it. |
| * |
| * If module auto-loading support is disabled then this function |
| * becomes a no-operation. |
| */ |
| int __request_module(bool wait, const char *fmt, ...) |
| { |
| va_list args; |
| char module_name[MODULE_NAME_LEN]; |
| unsigned int max_modprobes; |
| int ret; |
| static atomic_t kmod_concurrent = ATOMIC_INIT(0); |
| #define MAX_KMOD_CONCURRENT 50 /* Completely arbitrary value - KAO */ |
| static int kmod_loop_msg; |
| |
| /* |
| * We don't allow synchronous module loading from async. Module |
| * init may invoke async_synchronize_full() which will end up |
| * waiting for this task which already is waiting for the module |
| * loading to complete, leading to a deadlock. |
| */ |
| WARN_ON_ONCE(wait && current_is_async()); |
| |
| va_start(args, fmt); |
| ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args); |
| va_end(args); |
| if (ret >= MODULE_NAME_LEN) |
| return -ENAMETOOLONG; |
| |
| ret = security_kernel_module_request(module_name); |
| if (ret) |
| return ret; |
| |
| /* If modprobe needs a service that is in a module, we get a recursive |
| * loop. Limit the number of running kmod threads to max_threads/2 or |
| * MAX_KMOD_CONCURRENT, whichever is the smaller. A cleaner method |
| * would be to run the parents of this process, counting how many times |
| * kmod was invoked. That would mean accessing the internals of the |
| * process tables to get the command line, proc_pid_cmdline is static |
| * and it is not worth changing the proc code just to handle this case. |
| * KAO. |
| * |
| * "trace the ppid" is simple, but will fail if someone's |
| * parent exits. I think this is as good as it gets. --RR |
| */ |
| max_modprobes = min(max_threads/2, MAX_KMOD_CONCURRENT); |
| atomic_inc(&kmod_concurrent); |
| if (atomic_read(&kmod_concurrent) > max_modprobes) { |
| /* We may be blaming an innocent here, but unlikely */ |
| if (kmod_loop_msg < 5) { |
| printk(KERN_ERR |
| "request_module: runaway loop modprobe %s\n", |
| module_name); |
| kmod_loop_msg++; |
| } |
| atomic_dec(&kmod_concurrent); |
| return -ENOMEM; |
| } |
| |
| trace_module_request(module_name, wait, _RET_IP_); |
| |
| ret = call_modprobe(module_name, wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC); |
| |
| atomic_dec(&kmod_concurrent); |
| return ret; |
| } |
| EXPORT_SYMBOL(__request_module); |
| #endif /* CONFIG_MODULES */ |
| |
| /* |
| * This is the task which runs the usermode application |
| */ |
| static int ____call_usermodehelper(void *data) |
| { |
| struct subprocess_info *sub_info = data; |
| struct cred *new; |
| int retval; |
| |
| spin_lock_irq(¤t->sighand->siglock); |
| flush_signal_handlers(current, 1); |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| /* We can run anywhere, unlike our parent keventd(). */ |
| set_cpus_allowed_ptr(current, cpu_all_mask); |
| |
| /* |
| * Our parent is keventd, which runs with elevated scheduling priority. |
| * Avoid propagating that into the userspace child. |
| */ |
| set_user_nice(current, 0); |
| |
| retval = -ENOMEM; |
| new = prepare_kernel_cred(current); |
| if (!new) |
| goto fail; |
| |
| spin_lock(&umh_sysctl_lock); |
| new->cap_bset = cap_intersect(usermodehelper_bset, new->cap_bset); |
| new->cap_inheritable = cap_intersect(usermodehelper_inheritable, |
| new->cap_inheritable); |
| spin_unlock(&umh_sysctl_lock); |
| |
| if (sub_info->init) { |
| retval = sub_info->init(sub_info, new); |
| if (retval) { |
| abort_creds(new); |
| goto fail; |
| } |
| } |
| |
| commit_creds(new); |
| |
| retval = do_execve(sub_info->path, |
| (const char __user *const __user *)sub_info->argv, |
| (const char __user *const __user *)sub_info->envp); |
| if (!retval) |
| return 0; |
| |
| /* Exec failed? */ |
| fail: |
| sub_info->retval = retval; |
| do_exit(0); |
| } |
| |
| static int call_helper(void *data) |
| { |
| /* Worker thread started blocking khelper thread. */ |
| kmod_thread_locker = current; |
| return ____call_usermodehelper(data); |
| } |
| |
| static void call_usermodehelper_freeinfo(struct subprocess_info *info) |
| { |
| if (info->cleanup) |
| (*info->cleanup)(info); |
| kfree(info); |
| } |
| |
| static void umh_complete(struct subprocess_info *sub_info) |
| { |
| struct completion *comp = xchg(&sub_info->complete, NULL); |
| /* |
| * See call_usermodehelper_exec(). If xchg() returns NULL |
| * we own sub_info, the UMH_KILLABLE caller has gone away. |
| */ |
| if (comp) |
| complete(comp); |
| else |
| call_usermodehelper_freeinfo(sub_info); |
| } |
| |
| /* Keventd can't block, but this (a child) can. */ |
| static int wait_for_helper(void *data) |
| { |
| struct subprocess_info *sub_info = data; |
| pid_t pid; |
| |
| /* If SIGCLD is ignored sys_wait4 won't populate the status. */ |
| spin_lock_irq(¤t->sighand->siglock); |
| current->sighand->action[SIGCHLD-1].sa.sa_handler = SIG_DFL; |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| pid = kernel_thread(____call_usermodehelper, sub_info, SIGCHLD); |
| if (pid < 0) { |
| sub_info->retval = pid; |
| } else { |
| int ret = -ECHILD; |
| /* |
| * Normally it is bogus to call wait4() from in-kernel because |
| * wait4() wants to write the exit code to a userspace address. |
| * But wait_for_helper() always runs as keventd, and put_user() |
| * to a kernel address works OK for kernel threads, due to their |
| * having an mm_segment_t which spans the entire address space. |
| * |
| * Thus the __user pointer cast is valid here. |
| */ |
| sys_wait4(pid, (int __user *)&ret, 0, NULL); |
| |
| /* |
| * If ret is 0, either ____call_usermodehelper failed and the |
| * real error code is already in sub_info->retval or |
| * sub_info->retval is 0 anyway, so don't mess with it then. |
| */ |
| if (ret) |
| sub_info->retval = ret; |
| } |
| |
| umh_complete(sub_info); |
| do_exit(0); |
| } |
| |
| /* This is run by khelper thread */ |
| static void __call_usermodehelper(struct work_struct *work) |
| { |
| struct subprocess_info *sub_info = |
| container_of(work, struct subprocess_info, work); |
| int wait = sub_info->wait & ~UMH_KILLABLE; |
| pid_t pid; |
| |
| /* CLONE_VFORK: wait until the usermode helper has execve'd |
| * successfully We need the data structures to stay around |
| * until that is done. */ |
| if (wait == UMH_WAIT_PROC) |
| pid = kernel_thread(wait_for_helper, sub_info, |
| CLONE_FS | CLONE_FILES | SIGCHLD); |
| else { |
| pid = kernel_thread(call_helper, sub_info, |
| CLONE_VFORK | SIGCHLD); |
| /* Worker thread stopped blocking khelper thread. */ |
| kmod_thread_locker = NULL; |
| } |
| |
| switch (wait) { |
| case UMH_NO_WAIT: |
| call_usermodehelper_freeinfo(sub_info); |
| break; |
| |
| case UMH_WAIT_PROC: |
| if (pid > 0) |
| break; |
| /* FALLTHROUGH */ |
| case UMH_WAIT_EXEC: |
| if (pid < 0) |
| sub_info->retval = pid; |
| umh_complete(sub_info); |
| } |
| } |
| |
| /* |
| * If set, call_usermodehelper_exec() will exit immediately returning -EBUSY |
| * (used for preventing user land processes from being created after the user |
| * land has been frozen during a system-wide hibernation or suspend operation). |
| * Should always be manipulated under umhelper_sem acquired for write. |
| */ |
| static enum umh_disable_depth usermodehelper_disabled = UMH_DISABLED; |
| |
| /* Number of helpers running */ |
| static atomic_t running_helpers = ATOMIC_INIT(0); |
| |
| /* |
| * Wait queue head used by usermodehelper_disable() to wait for all running |
| * helpers to finish. |
| */ |
| static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq); |
| |
| /* |
| * Used by usermodehelper_read_lock_wait() to wait for usermodehelper_disabled |
| * to become 'false'. |
| */ |
| static DECLARE_WAIT_QUEUE_HEAD(usermodehelper_disabled_waitq); |
| |
| /* |
| * Time to wait for running_helpers to become zero before the setting of |
| * usermodehelper_disabled in usermodehelper_disable() fails |
| */ |
| #define RUNNING_HELPERS_TIMEOUT (5 * HZ) |
| |
| int usermodehelper_read_trylock(void) |
| { |
| DEFINE_WAIT(wait); |
| int ret = 0; |
| |
| down_read(&umhelper_sem); |
| for (;;) { |
| prepare_to_wait(&usermodehelper_disabled_waitq, &wait, |
| TASK_INTERRUPTIBLE); |
| if (!usermodehelper_disabled) |
| break; |
| |
| if (usermodehelper_disabled == UMH_DISABLED) |
| ret = -EAGAIN; |
| |
| up_read(&umhelper_sem); |
| |
| if (ret) |
| break; |
| |
| schedule(); |
| try_to_freeze(); |
| |
| down_read(&umhelper_sem); |
| } |
| finish_wait(&usermodehelper_disabled_waitq, &wait); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(usermodehelper_read_trylock); |
| |
| long usermodehelper_read_lock_wait(long timeout) |
| { |
| DEFINE_WAIT(wait); |
| |
| if (timeout < 0) |
| return -EINVAL; |
| |
| down_read(&umhelper_sem); |
| for (;;) { |
| prepare_to_wait(&usermodehelper_disabled_waitq, &wait, |
| TASK_UNINTERRUPTIBLE); |
| if (!usermodehelper_disabled) |
| break; |
| |
| up_read(&umhelper_sem); |
| |
| timeout = schedule_timeout(timeout); |
| if (!timeout) |
| break; |
| |
| down_read(&umhelper_sem); |
| } |
| finish_wait(&usermodehelper_disabled_waitq, &wait); |
| return timeout; |
| } |
| EXPORT_SYMBOL_GPL(usermodehelper_read_lock_wait); |
| |
| void usermodehelper_read_unlock(void) |
| { |
| up_read(&umhelper_sem); |
| } |
| EXPORT_SYMBOL_GPL(usermodehelper_read_unlock); |
| |
| /** |
| * __usermodehelper_set_disable_depth - Modify usermodehelper_disabled. |
| * @depth: New value to assign to usermodehelper_disabled. |
| * |
| * Change the value of usermodehelper_disabled (under umhelper_sem locked for |
| * writing) and wakeup tasks waiting for it to change. |
| */ |
| void __usermodehelper_set_disable_depth(enum umh_disable_depth depth) |
| { |
| down_write(&umhelper_sem); |
| usermodehelper_disabled = depth; |
| wake_up(&usermodehelper_disabled_waitq); |
| up_write(&umhelper_sem); |
| } |
| |
| /** |
| * __usermodehelper_disable - Prevent new helpers from being started. |
| * @depth: New value to assign to usermodehelper_disabled. |
| * |
| * Set usermodehelper_disabled to @depth and wait for running helpers to exit. |
| */ |
| int __usermodehelper_disable(enum umh_disable_depth depth) |
| { |
| long retval; |
| |
| if (!depth) |
| return -EINVAL; |
| |
| down_write(&umhelper_sem); |
| usermodehelper_disabled = depth; |
| up_write(&umhelper_sem); |
| |
| /* |
| * From now on call_usermodehelper_exec() won't start any new |
| * helpers, so it is sufficient if running_helpers turns out to |
| * be zero at one point (it may be increased later, but that |
| * doesn't matter). |
| */ |
| retval = wait_event_timeout(running_helpers_waitq, |
| atomic_read(&running_helpers) == 0, |
| RUNNING_HELPERS_TIMEOUT); |
| if (retval) |
| return 0; |
| |
| __usermodehelper_set_disable_depth(UMH_ENABLED); |
| return -EAGAIN; |
| } |
| |
| static void helper_lock(void) |
| { |
| atomic_inc(&running_helpers); |
| smp_mb__after_atomic_inc(); |
| } |
| |
| static void helper_unlock(void) |
| { |
| if (atomic_dec_and_test(&running_helpers)) |
| wake_up(&running_helpers_waitq); |
| } |
| |
| /** |
| * call_usermodehelper_setup - prepare to call a usermode helper |
| * @path: path to usermode executable |
| * @argv: arg vector for process |
| * @envp: environment for process |
| * @gfp_mask: gfp mask for memory allocation |
| * @cleanup: a cleanup function |
| * @init: an init function |
| * @data: arbitrary context sensitive data |
| * |
| * Returns either %NULL on allocation failure, or a subprocess_info |
| * structure. This should be passed to call_usermodehelper_exec to |
| * exec the process and free the structure. |
| * |
| * The init function is used to customize the helper process prior to |
| * exec. A non-zero return code causes the process to error out, exit, |
| * and return the failure to the calling process |
| * |
| * The cleanup function is just before ethe subprocess_info is about to |
| * be freed. This can be used for freeing the argv and envp. The |
| * Function must be runnable in either a process context or the |
| * context in which call_usermodehelper_exec is called. |
| */ |
| struct subprocess_info *call_usermodehelper_setup(char *path, char **argv, |
| char **envp, gfp_t gfp_mask, |
| int (*init)(struct subprocess_info *info, struct cred *new), |
| void (*cleanup)(struct subprocess_info *info), |
| void *data) |
| { |
| struct subprocess_info *sub_info; |
| sub_info = kzalloc(sizeof(struct subprocess_info), gfp_mask); |
| if (!sub_info) |
| goto out; |
| |
| INIT_WORK(&sub_info->work, __call_usermodehelper); |
| sub_info->path = path; |
| sub_info->argv = argv; |
| sub_info->envp = envp; |
| |
| sub_info->cleanup = cleanup; |
| sub_info->init = init; |
| sub_info->data = data; |
| out: |
| return sub_info; |
| } |
| EXPORT_SYMBOL(call_usermodehelper_setup); |
| |
| /** |
| * call_usermodehelper_exec - start a usermode application |
| * @sub_info: information about the subprocessa |
| * @wait: wait for the application to finish and return status. |
| * when UMH_NO_WAIT don't wait at all, but you get no useful error back |
| * when the program couldn't be exec'ed. This makes it safe to call |
| * from interrupt context. |
| * |
| * Runs a user-space application. The application is started |
| * asynchronously if wait is not set, and runs as a child of keventd. |
| * (ie. it runs with full root capabilities). |
| */ |
| int call_usermodehelper_exec(struct subprocess_info *sub_info, int wait) |
| { |
| DECLARE_COMPLETION_ONSTACK(done); |
| int retval = 0; |
| |
| helper_lock(); |
| if (sub_info->path[0] == '\0') |
| goto out; |
| |
| if (!khelper_wq || usermodehelper_disabled) { |
| retval = -EBUSY; |
| goto out; |
| } |
| /* |
| * Worker thread must not wait for khelper thread at below |
| * wait_for_completion() if the thread was created with CLONE_VFORK |
| * flag, for khelper thread is already waiting for the thread at |
| * wait_for_completion() in do_fork(). |
| */ |
| if (wait != UMH_NO_WAIT && current == kmod_thread_locker) { |
| retval = -EBUSY; |
| goto out; |
| } |
| |
| sub_info->complete = &done; |
| sub_info->wait = wait; |
| |
| queue_work(khelper_wq, &sub_info->work); |
| if (wait == UMH_NO_WAIT) /* task has freed sub_info */ |
| goto unlock; |
| |
| if (wait & UMH_KILLABLE) { |
| retval = wait_for_completion_killable(&done); |
| if (!retval) |
| goto wait_done; |
| |
| /* umh_complete() will see NULL and free sub_info */ |
| if (xchg(&sub_info->complete, NULL)) |
| goto unlock; |
| /* fallthrough, umh_complete() was already called */ |
| } |
| |
| wait_for_completion(&done); |
| wait_done: |
| retval = sub_info->retval; |
| out: |
| call_usermodehelper_freeinfo(sub_info); |
| unlock: |
| helper_unlock(); |
| return retval; |
| } |
| EXPORT_SYMBOL(call_usermodehelper_exec); |
| |
| /** |
| * call_usermodehelper() - prepare and start a usermode application |
| * @path: path to usermode executable |
| * @argv: arg vector for process |
| * @envp: environment for process |
| * @wait: wait for the application to finish and return status. |
| * when UMH_NO_WAIT don't wait at all, but you get no useful error back |
| * when the program couldn't be exec'ed. This makes it safe to call |
| * from interrupt context. |
| * |
| * This function is the equivalent to use call_usermodehelper_setup() and |
| * call_usermodehelper_exec(). |
| */ |
| int call_usermodehelper(char *path, char **argv, char **envp, int wait) |
| { |
| struct subprocess_info *info; |
| gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL; |
| |
| info = call_usermodehelper_setup(path, argv, envp, gfp_mask, |
| NULL, NULL, NULL); |
| if (info == NULL) |
| return -ENOMEM; |
| |
| return call_usermodehelper_exec(info, wait); |
| } |
| EXPORT_SYMBOL(call_usermodehelper); |
| |
| static int proc_cap_handler(struct ctl_table *table, int write, |
| void __user *buffer, size_t *lenp, loff_t *ppos) |
| { |
| struct ctl_table t; |
| unsigned long cap_array[_KERNEL_CAPABILITY_U32S]; |
| kernel_cap_t new_cap; |
| int err, i; |
| |
| if (write && (!capable(CAP_SETPCAP) || |
| !capable(CAP_SYS_MODULE))) |
| return -EPERM; |
| |
| /* |
| * convert from the global kernel_cap_t to the ulong array to print to |
| * userspace if this is a read. |
| */ |
| spin_lock(&umh_sysctl_lock); |
| for (i = 0; i < _KERNEL_CAPABILITY_U32S; i++) { |
| if (table->data == CAP_BSET) |
| cap_array[i] = usermodehelper_bset.cap[i]; |
| else if (table->data == CAP_PI) |
| cap_array[i] = usermodehelper_inheritable.cap[i]; |
| else |
| BUG(); |
| } |
| spin_unlock(&umh_sysctl_lock); |
| |
| t = *table; |
| t.data = &cap_array; |
| |
| /* |
| * actually read or write and array of ulongs from userspace. Remember |
| * these are least significant 32 bits first |
| */ |
| err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos); |
| if (err < 0) |
| return err; |
| |
| /* |
| * convert from the sysctl array of ulongs to the kernel_cap_t |
| * internal representation |
| */ |
| for (i = 0; i < _KERNEL_CAPABILITY_U32S; i++) |
| new_cap.cap[i] = cap_array[i]; |
| |
| /* |
| * Drop everything not in the new_cap (but don't add things) |
| */ |
| spin_lock(&umh_sysctl_lock); |
| if (write) { |
| if (table->data == CAP_BSET) |
| usermodehelper_bset = cap_intersect(usermodehelper_bset, new_cap); |
| if (table->data == CAP_PI) |
| usermodehelper_inheritable = cap_intersect(usermodehelper_inheritable, new_cap); |
| } |
| spin_unlock(&umh_sysctl_lock); |
| |
| return 0; |
| } |
| |
| struct ctl_table usermodehelper_table[] = { |
| { |
| .procname = "bset", |
| .data = CAP_BSET, |
| .maxlen = _KERNEL_CAPABILITY_U32S * sizeof(unsigned long), |
| .mode = 0600, |
| .proc_handler = proc_cap_handler, |
| }, |
| { |
| .procname = "inheritable", |
| .data = CAP_PI, |
| .maxlen = _KERNEL_CAPABILITY_U32S * sizeof(unsigned long), |
| .mode = 0600, |
| .proc_handler = proc_cap_handler, |
| }, |
| { } |
| }; |
| |
| void __init usermodehelper_init(void) |
| { |
| khelper_wq = create_singlethread_workqueue("khelper"); |
| BUG_ON(!khelper_wq); |
| } |