| /* |
| * /proc/sys support |
| */ |
| #include <linux/init.h> |
| #include <linux/sysctl.h> |
| #include <linux/poll.h> |
| #include <linux/proc_fs.h> |
| #include <linux/security.h> |
| #include <linux/namei.h> |
| #include <linux/module.h> |
| #include "internal.h" |
| |
| static const struct dentry_operations proc_sys_dentry_operations; |
| static const struct file_operations proc_sys_file_operations; |
| static const struct inode_operations proc_sys_inode_operations; |
| static const struct file_operations proc_sys_dir_file_operations; |
| static const struct inode_operations proc_sys_dir_operations; |
| |
| void proc_sys_poll_notify(struct ctl_table_poll *poll) |
| { |
| if (!poll) |
| return; |
| |
| atomic_inc(&poll->event); |
| wake_up_interruptible(&poll->wait); |
| } |
| |
| static struct ctl_table root_table[] = { |
| { |
| .procname = "", |
| .mode = S_IFDIR|S_IRUGO|S_IXUGO, |
| }, |
| { } |
| }; |
| static struct ctl_table_root sysctl_table_root = { |
| .default_set.dir.header = { |
| {{.count = 1, |
| .nreg = 1, |
| .ctl_table = root_table }}, |
| .ctl_table_arg = root_table, |
| .root = &sysctl_table_root, |
| .set = &sysctl_table_root.default_set, |
| }, |
| }; |
| |
| static DEFINE_SPINLOCK(sysctl_lock); |
| |
| static void drop_sysctl_table(struct ctl_table_header *header); |
| static int sysctl_follow_link(struct ctl_table_header **phead, |
| struct ctl_table **pentry, struct nsproxy *namespaces); |
| static int insert_links(struct ctl_table_header *head); |
| static void put_links(struct ctl_table_header *header); |
| |
| static void sysctl_print_dir(struct ctl_dir *dir) |
| { |
| if (dir->header.parent) |
| sysctl_print_dir(dir->header.parent); |
| printk(KERN_CONT "%s/", dir->header.ctl_table[0].procname); |
| } |
| |
| static int namecmp(const char *name1, int len1, const char *name2, int len2) |
| { |
| int minlen; |
| int cmp; |
| |
| minlen = len1; |
| if (minlen > len2) |
| minlen = len2; |
| |
| cmp = memcmp(name1, name2, minlen); |
| if (cmp == 0) |
| cmp = len1 - len2; |
| return cmp; |
| } |
| |
| static struct ctl_table *find_entry(struct ctl_table_header **phead, |
| struct ctl_dir *dir, const char *name, int namelen) |
| { |
| struct ctl_table_header *head; |
| struct ctl_table *entry; |
| struct rb_node *node = dir->root.rb_node; |
| |
| while (node) |
| { |
| struct ctl_node *ctl_node; |
| const char *procname; |
| int cmp; |
| |
| ctl_node = rb_entry(node, struct ctl_node, node); |
| head = ctl_node->header; |
| entry = &head->ctl_table[ctl_node - head->node]; |
| procname = entry->procname; |
| |
| cmp = namecmp(name, namelen, procname, strlen(procname)); |
| if (cmp < 0) |
| node = node->rb_left; |
| else if (cmp > 0) |
| node = node->rb_right; |
| else { |
| *phead = head; |
| return entry; |
| } |
| } |
| return NULL; |
| } |
| |
| static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry) |
| { |
| struct rb_node *node = &head->node[entry - head->ctl_table].node; |
| struct rb_node **p = &head->parent->root.rb_node; |
| struct rb_node *parent = NULL; |
| const char *name = entry->procname; |
| int namelen = strlen(name); |
| |
| while (*p) { |
| struct ctl_table_header *parent_head; |
| struct ctl_table *parent_entry; |
| struct ctl_node *parent_node; |
| const char *parent_name; |
| int cmp; |
| |
| parent = *p; |
| parent_node = rb_entry(parent, struct ctl_node, node); |
| parent_head = parent_node->header; |
| parent_entry = &parent_head->ctl_table[parent_node - parent_head->node]; |
| parent_name = parent_entry->procname; |
| |
| cmp = namecmp(name, namelen, parent_name, strlen(parent_name)); |
| if (cmp < 0) |
| p = &(*p)->rb_left; |
| else if (cmp > 0) |
| p = &(*p)->rb_right; |
| else { |
| printk(KERN_ERR "sysctl duplicate entry: "); |
| sysctl_print_dir(head->parent); |
| printk(KERN_CONT "/%s\n", entry->procname); |
| return -EEXIST; |
| } |
| } |
| |
| rb_link_node(node, parent, p); |
| return 0; |
| } |
| |
| static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry) |
| { |
| struct rb_node *node = &head->node[entry - head->ctl_table].node; |
| |
| rb_erase(node, &head->parent->root); |
| } |
| |
| static void init_header(struct ctl_table_header *head, |
| struct ctl_table_root *root, struct ctl_table_set *set, |
| struct ctl_node *node, struct ctl_table *table) |
| { |
| head->ctl_table = table; |
| head->ctl_table_arg = table; |
| head->used = 0; |
| head->count = 1; |
| head->nreg = 1; |
| head->unregistering = NULL; |
| head->root = root; |
| head->set = set; |
| head->parent = NULL; |
| head->node = node; |
| if (node) { |
| struct ctl_table *entry; |
| for (entry = table; entry->procname; entry++, node++) { |
| rb_init_node(&node->node); |
| node->header = head; |
| } |
| } |
| } |
| |
| static void erase_header(struct ctl_table_header *head) |
| { |
| struct ctl_table *entry; |
| for (entry = head->ctl_table; entry->procname; entry++) |
| erase_entry(head, entry); |
| } |
| |
| static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) |
| { |
| struct ctl_table *entry; |
| int err; |
| |
| dir->header.nreg++; |
| header->parent = dir; |
| err = insert_links(header); |
| if (err) |
| goto fail_links; |
| for (entry = header->ctl_table; entry->procname; entry++) { |
| err = insert_entry(header, entry); |
| if (err) |
| goto fail; |
| } |
| return 0; |
| fail: |
| erase_header(header); |
| put_links(header); |
| fail_links: |
| header->parent = NULL; |
| drop_sysctl_table(&dir->header); |
| return err; |
| } |
| |
| /* called under sysctl_lock */ |
| static int use_table(struct ctl_table_header *p) |
| { |
| if (unlikely(p->unregistering)) |
| return 0; |
| p->used++; |
| return 1; |
| } |
| |
| /* called under sysctl_lock */ |
| static void unuse_table(struct ctl_table_header *p) |
| { |
| if (!--p->used) |
| if (unlikely(p->unregistering)) |
| complete(p->unregistering); |
| } |
| |
| /* called under sysctl_lock, will reacquire if has to wait */ |
| static void start_unregistering(struct ctl_table_header *p) |
| { |
| /* |
| * if p->used is 0, nobody will ever touch that entry again; |
| * we'll eliminate all paths to it before dropping sysctl_lock |
| */ |
| if (unlikely(p->used)) { |
| struct completion wait; |
| init_completion(&wait); |
| p->unregistering = &wait; |
| spin_unlock(&sysctl_lock); |
| wait_for_completion(&wait); |
| spin_lock(&sysctl_lock); |
| } else { |
| /* anything non-NULL; we'll never dereference it */ |
| p->unregistering = ERR_PTR(-EINVAL); |
| } |
| /* |
| * do not remove from the list until nobody holds it; walking the |
| * list in do_sysctl() relies on that. |
| */ |
| erase_header(p); |
| } |
| |
| static void sysctl_head_get(struct ctl_table_header *head) |
| { |
| spin_lock(&sysctl_lock); |
| head->count++; |
| spin_unlock(&sysctl_lock); |
| } |
| |
| void sysctl_head_put(struct ctl_table_header *head) |
| { |
| spin_lock(&sysctl_lock); |
| if (!--head->count) |
| kfree_rcu(head, rcu); |
| spin_unlock(&sysctl_lock); |
| } |
| |
| static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) |
| { |
| if (!head) |
| BUG(); |
| spin_lock(&sysctl_lock); |
| if (!use_table(head)) |
| head = ERR_PTR(-ENOENT); |
| spin_unlock(&sysctl_lock); |
| return head; |
| } |
| |
| static void sysctl_head_finish(struct ctl_table_header *head) |
| { |
| if (!head) |
| return; |
| spin_lock(&sysctl_lock); |
| unuse_table(head); |
| spin_unlock(&sysctl_lock); |
| } |
| |
| static struct ctl_table_set * |
| lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces) |
| { |
| struct ctl_table_set *set = &root->default_set; |
| if (root->lookup) |
| set = root->lookup(root, namespaces); |
| return set; |
| } |
| |
| static struct ctl_table *lookup_entry(struct ctl_table_header **phead, |
| struct ctl_dir *dir, |
| const char *name, int namelen) |
| { |
| struct ctl_table_header *head; |
| struct ctl_table *entry; |
| |
| spin_lock(&sysctl_lock); |
| entry = find_entry(&head, dir, name, namelen); |
| if (entry && use_table(head)) |
| *phead = head; |
| else |
| entry = NULL; |
| spin_unlock(&sysctl_lock); |
| return entry; |
| } |
| |
| static struct ctl_node *first_usable_entry(struct rb_node *node) |
| { |
| struct ctl_node *ctl_node; |
| |
| for (;node; node = rb_next(node)) { |
| ctl_node = rb_entry(node, struct ctl_node, node); |
| if (use_table(ctl_node->header)) |
| return ctl_node; |
| } |
| return NULL; |
| } |
| |
| static void first_entry(struct ctl_dir *dir, |
| struct ctl_table_header **phead, struct ctl_table **pentry) |
| { |
| struct ctl_table_header *head = NULL; |
| struct ctl_table *entry = NULL; |
| struct ctl_node *ctl_node; |
| |
| spin_lock(&sysctl_lock); |
| ctl_node = first_usable_entry(rb_first(&dir->root)); |
| spin_unlock(&sysctl_lock); |
| if (ctl_node) { |
| head = ctl_node->header; |
| entry = &head->ctl_table[ctl_node - head->node]; |
| } |
| *phead = head; |
| *pentry = entry; |
| } |
| |
| static void next_entry(struct ctl_table_header **phead, struct ctl_table **pentry) |
| { |
| struct ctl_table_header *head = *phead; |
| struct ctl_table *entry = *pentry; |
| struct ctl_node *ctl_node = &head->node[entry - head->ctl_table]; |
| |
| spin_lock(&sysctl_lock); |
| unuse_table(head); |
| |
| ctl_node = first_usable_entry(rb_next(&ctl_node->node)); |
| spin_unlock(&sysctl_lock); |
| head = NULL; |
| if (ctl_node) { |
| head = ctl_node->header; |
| entry = &head->ctl_table[ctl_node - head->node]; |
| } |
| *phead = head; |
| *pentry = entry; |
| } |
| |
| void register_sysctl_root(struct ctl_table_root *root) |
| { |
| } |
| |
| /* |
| * sysctl_perm does NOT grant the superuser all rights automatically, because |
| * some sysctl variables are readonly even to root. |
| */ |
| |
| static int test_perm(int mode, int op) |
| { |
| if (!current_euid()) |
| mode >>= 6; |
| else if (in_egroup_p(0)) |
| mode >>= 3; |
| if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) |
| return 0; |
| return -EACCES; |
| } |
| |
| static int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op) |
| { |
| int mode; |
| |
| if (root->permissions) |
| mode = root->permissions(root, current->nsproxy, table); |
| else |
| mode = table->mode; |
| |
| return test_perm(mode, op); |
| } |
| |
| static struct inode *proc_sys_make_inode(struct super_block *sb, |
| struct ctl_table_header *head, struct ctl_table *table) |
| { |
| struct inode *inode; |
| struct proc_inode *ei; |
| |
| inode = new_inode(sb); |
| if (!inode) |
| goto out; |
| |
| inode->i_ino = get_next_ino(); |
| |
| sysctl_head_get(head); |
| ei = PROC_I(inode); |
| ei->sysctl = head; |
| ei->sysctl_entry = table; |
| |
| inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; |
| inode->i_mode = table->mode; |
| if (!S_ISDIR(table->mode)) { |
| inode->i_mode |= S_IFREG; |
| inode->i_op = &proc_sys_inode_operations; |
| inode->i_fop = &proc_sys_file_operations; |
| } else { |
| inode->i_mode |= S_IFDIR; |
| inode->i_op = &proc_sys_dir_operations; |
| inode->i_fop = &proc_sys_dir_file_operations; |
| } |
| out: |
| return inode; |
| } |
| |
| static struct ctl_table_header *grab_header(struct inode *inode) |
| { |
| struct ctl_table_header *head = PROC_I(inode)->sysctl; |
| if (!head) |
| head = &sysctl_table_root.default_set.dir.header; |
| return sysctl_head_grab(head); |
| } |
| |
| static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, |
| struct nameidata *nd) |
| { |
| struct ctl_table_header *head = grab_header(dir); |
| struct ctl_table_header *h = NULL; |
| struct qstr *name = &dentry->d_name; |
| struct ctl_table *p; |
| struct inode *inode; |
| struct dentry *err = ERR_PTR(-ENOENT); |
| struct ctl_dir *ctl_dir; |
| int ret; |
| |
| if (IS_ERR(head)) |
| return ERR_CAST(head); |
| |
| ctl_dir = container_of(head, struct ctl_dir, header); |
| |
| p = lookup_entry(&h, ctl_dir, name->name, name->len); |
| if (!p) |
| goto out; |
| |
| ret = sysctl_follow_link(&h, &p, current->nsproxy); |
| err = ERR_PTR(ret); |
| if (ret) |
| goto out; |
| |
| err = ERR_PTR(-ENOMEM); |
| inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); |
| if (h) |
| sysctl_head_finish(h); |
| |
| if (!inode) |
| goto out; |
| |
| err = NULL; |
| d_set_d_op(dentry, &proc_sys_dentry_operations); |
| d_add(dentry, inode); |
| |
| out: |
| sysctl_head_finish(head); |
| return err; |
| } |
| |
| static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf, |
| size_t count, loff_t *ppos, int write) |
| { |
| struct inode *inode = filp->f_path.dentry->d_inode; |
| struct ctl_table_header *head = grab_header(inode); |
| struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
| ssize_t error; |
| size_t res; |
| |
| if (IS_ERR(head)) |
| return PTR_ERR(head); |
| |
| /* |
| * At this point we know that the sysctl was not unregistered |
| * and won't be until we finish. |
| */ |
| error = -EPERM; |
| if (sysctl_perm(head->root, table, write ? MAY_WRITE : MAY_READ)) |
| goto out; |
| |
| /* if that can happen at all, it should be -EINVAL, not -EISDIR */ |
| error = -EINVAL; |
| if (!table->proc_handler) |
| goto out; |
| |
| /* careful: calling conventions are nasty here */ |
| res = count; |
| error = table->proc_handler(table, write, buf, &res, ppos); |
| if (!error) |
| error = res; |
| out: |
| sysctl_head_finish(head); |
| |
| return error; |
| } |
| |
| static ssize_t proc_sys_read(struct file *filp, char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0); |
| } |
| |
| static ssize_t proc_sys_write(struct file *filp, const char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1); |
| } |
| |
| static int proc_sys_open(struct inode *inode, struct file *filp) |
| { |
| struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
| |
| if (table->poll) |
| filp->private_data = proc_sys_poll_event(table->poll); |
| |
| return 0; |
| } |
| |
| static unsigned int proc_sys_poll(struct file *filp, poll_table *wait) |
| { |
| struct inode *inode = filp->f_path.dentry->d_inode; |
| struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
| unsigned long event = (unsigned long)filp->private_data; |
| unsigned int ret = DEFAULT_POLLMASK; |
| |
| if (!table->proc_handler) |
| goto out; |
| |
| if (!table->poll) |
| goto out; |
| |
| poll_wait(filp, &table->poll->wait, wait); |
| |
| if (event != atomic_read(&table->poll->event)) { |
| filp->private_data = proc_sys_poll_event(table->poll); |
| ret = POLLIN | POLLRDNORM | POLLERR | POLLPRI; |
| } |
| |
| out: |
| return ret; |
| } |
| |
| static int proc_sys_fill_cache(struct file *filp, void *dirent, |
| filldir_t filldir, |
| struct ctl_table_header *head, |
| struct ctl_table *table) |
| { |
| struct dentry *child, *dir = filp->f_path.dentry; |
| struct inode *inode; |
| struct qstr qname; |
| ino_t ino = 0; |
| unsigned type = DT_UNKNOWN; |
| |
| qname.name = table->procname; |
| qname.len = strlen(table->procname); |
| qname.hash = full_name_hash(qname.name, qname.len); |
| |
| child = d_lookup(dir, &qname); |
| if (!child) { |
| child = d_alloc(dir, &qname); |
| if (child) { |
| inode = proc_sys_make_inode(dir->d_sb, head, table); |
| if (!inode) { |
| dput(child); |
| return -ENOMEM; |
| } else { |
| d_set_d_op(child, &proc_sys_dentry_operations); |
| d_add(child, inode); |
| } |
| } else { |
| return -ENOMEM; |
| } |
| } |
| inode = child->d_inode; |
| ino = inode->i_ino; |
| type = inode->i_mode >> 12; |
| dput(child); |
| return !!filldir(dirent, qname.name, qname.len, filp->f_pos, ino, type); |
| } |
| |
| static int proc_sys_link_fill_cache(struct file *filp, void *dirent, |
| filldir_t filldir, |
| struct ctl_table_header *head, |
| struct ctl_table *table) |
| { |
| int err, ret = 0; |
| head = sysctl_head_grab(head); |
| |
| /* It is not an error if we can not follow the link ignore it */ |
| err = sysctl_follow_link(&head, &table, current->nsproxy); |
| if (err) |
| goto out; |
| |
| ret = proc_sys_fill_cache(filp, dirent, filldir, head, table); |
| out: |
| sysctl_head_finish(head); |
| return ret; |
| } |
| |
| static int scan(struct ctl_table_header *head, ctl_table *table, |
| unsigned long *pos, struct file *file, |
| void *dirent, filldir_t filldir) |
| { |
| int res; |
| |
| if ((*pos)++ < file->f_pos) |
| return 0; |
| |
| if (unlikely(S_ISLNK(table->mode))) |
| res = proc_sys_link_fill_cache(file, dirent, filldir, head, table); |
| else |
| res = proc_sys_fill_cache(file, dirent, filldir, head, table); |
| |
| if (res == 0) |
| file->f_pos = *pos; |
| |
| return res; |
| } |
| |
| static int proc_sys_readdir(struct file *filp, void *dirent, filldir_t filldir) |
| { |
| struct dentry *dentry = filp->f_path.dentry; |
| struct inode *inode = dentry->d_inode; |
| struct ctl_table_header *head = grab_header(inode); |
| struct ctl_table_header *h = NULL; |
| struct ctl_table *entry; |
| struct ctl_dir *ctl_dir; |
| unsigned long pos; |
| int ret = -EINVAL; |
| |
| if (IS_ERR(head)) |
| return PTR_ERR(head); |
| |
| ctl_dir = container_of(head, struct ctl_dir, header); |
| |
| ret = 0; |
| /* Avoid a switch here: arm builds fail with missing __cmpdi2 */ |
| if (filp->f_pos == 0) { |
| if (filldir(dirent, ".", 1, filp->f_pos, |
| inode->i_ino, DT_DIR) < 0) |
| goto out; |
| filp->f_pos++; |
| } |
| if (filp->f_pos == 1) { |
| if (filldir(dirent, "..", 2, filp->f_pos, |
| parent_ino(dentry), DT_DIR) < 0) |
| goto out; |
| filp->f_pos++; |
| } |
| pos = 2; |
| |
| for (first_entry(ctl_dir, &h, &entry); h; next_entry(&h, &entry)) { |
| ret = scan(h, entry, &pos, filp, dirent, filldir); |
| if (ret) { |
| sysctl_head_finish(h); |
| break; |
| } |
| } |
| ret = 1; |
| out: |
| sysctl_head_finish(head); |
| return ret; |
| } |
| |
| static int proc_sys_permission(struct inode *inode, int mask) |
| { |
| /* |
| * sysctl entries that are not writeable, |
| * are _NOT_ writeable, capabilities or not. |
| */ |
| struct ctl_table_header *head; |
| struct ctl_table *table; |
| int error; |
| |
| /* Executable files are not allowed under /proc/sys/ */ |
| if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) |
| return -EACCES; |
| |
| head = grab_header(inode); |
| if (IS_ERR(head)) |
| return PTR_ERR(head); |
| |
| table = PROC_I(inode)->sysctl_entry; |
| if (!table) /* global root - r-xr-xr-x */ |
| error = mask & MAY_WRITE ? -EACCES : 0; |
| else /* Use the permissions on the sysctl table entry */ |
| error = sysctl_perm(head->root, table, mask & ~MAY_NOT_BLOCK); |
| |
| sysctl_head_finish(head); |
| return error; |
| } |
| |
| static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr) |
| { |
| struct inode *inode = dentry->d_inode; |
| int error; |
| |
| if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) |
| return -EPERM; |
| |
| error = inode_change_ok(inode, attr); |
| if (error) |
| return error; |
| |
| if ((attr->ia_valid & ATTR_SIZE) && |
| attr->ia_size != i_size_read(inode)) { |
| error = vmtruncate(inode, attr->ia_size); |
| if (error) |
| return error; |
| } |
| |
| setattr_copy(inode, attr); |
| mark_inode_dirty(inode); |
| return 0; |
| } |
| |
| static int proc_sys_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) |
| { |
| struct inode *inode = dentry->d_inode; |
| struct ctl_table_header *head = grab_header(inode); |
| struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
| |
| if (IS_ERR(head)) |
| return PTR_ERR(head); |
| |
| generic_fillattr(inode, stat); |
| if (table) |
| stat->mode = (stat->mode & S_IFMT) | table->mode; |
| |
| sysctl_head_finish(head); |
| return 0; |
| } |
| |
| static const struct file_operations proc_sys_file_operations = { |
| .open = proc_sys_open, |
| .poll = proc_sys_poll, |
| .read = proc_sys_read, |
| .write = proc_sys_write, |
| .llseek = default_llseek, |
| }; |
| |
| static const struct file_operations proc_sys_dir_file_operations = { |
| .read = generic_read_dir, |
| .readdir = proc_sys_readdir, |
| .llseek = generic_file_llseek, |
| }; |
| |
| static const struct inode_operations proc_sys_inode_operations = { |
| .permission = proc_sys_permission, |
| .setattr = proc_sys_setattr, |
| .getattr = proc_sys_getattr, |
| }; |
| |
| static const struct inode_operations proc_sys_dir_operations = { |
| .lookup = proc_sys_lookup, |
| .permission = proc_sys_permission, |
| .setattr = proc_sys_setattr, |
| .getattr = proc_sys_getattr, |
| }; |
| |
| static int proc_sys_revalidate(struct dentry *dentry, struct nameidata *nd) |
| { |
| if (nd->flags & LOOKUP_RCU) |
| return -ECHILD; |
| return !PROC_I(dentry->d_inode)->sysctl->unregistering; |
| } |
| |
| static int proc_sys_delete(const struct dentry *dentry) |
| { |
| return !!PROC_I(dentry->d_inode)->sysctl->unregistering; |
| } |
| |
| static int sysctl_is_seen(struct ctl_table_header *p) |
| { |
| struct ctl_table_set *set = p->set; |
| int res; |
| spin_lock(&sysctl_lock); |
| if (p->unregistering) |
| res = 0; |
| else if (!set->is_seen) |
| res = 1; |
| else |
| res = set->is_seen(set); |
| spin_unlock(&sysctl_lock); |
| return res; |
| } |
| |
| static int proc_sys_compare(const struct dentry *parent, |
| const struct inode *pinode, |
| const struct dentry *dentry, const struct inode *inode, |
| unsigned int len, const char *str, const struct qstr *name) |
| { |
| struct ctl_table_header *head; |
| /* Although proc doesn't have negative dentries, rcu-walk means |
| * that inode here can be NULL */ |
| /* AV: can it, indeed? */ |
| if (!inode) |
| return 1; |
| if (name->len != len) |
| return 1; |
| if (memcmp(name->name, str, len)) |
| return 1; |
| head = rcu_dereference(PROC_I(inode)->sysctl); |
| return !head || !sysctl_is_seen(head); |
| } |
| |
| static const struct dentry_operations proc_sys_dentry_operations = { |
| .d_revalidate = proc_sys_revalidate, |
| .d_delete = proc_sys_delete, |
| .d_compare = proc_sys_compare, |
| }; |
| |
| static struct ctl_dir *find_subdir(struct ctl_dir *dir, |
| const char *name, int namelen) |
| { |
| struct ctl_table_header *head; |
| struct ctl_table *entry; |
| |
| entry = find_entry(&head, dir, name, namelen); |
| if (!entry) |
| return ERR_PTR(-ENOENT); |
| if (!S_ISDIR(entry->mode)) |
| return ERR_PTR(-ENOTDIR); |
| return container_of(head, struct ctl_dir, header); |
| } |
| |
| static struct ctl_dir *new_dir(struct ctl_table_set *set, |
| const char *name, int namelen) |
| { |
| struct ctl_table *table; |
| struct ctl_dir *new; |
| struct ctl_node *node; |
| char *new_name; |
| |
| new = kzalloc(sizeof(*new) + sizeof(struct ctl_node) + |
| sizeof(struct ctl_table)*2 + namelen + 1, |
| GFP_KERNEL); |
| if (!new) |
| return NULL; |
| |
| node = (struct ctl_node *)(new + 1); |
| table = (struct ctl_table *)(node + 1); |
| new_name = (char *)(table + 2); |
| memcpy(new_name, name, namelen); |
| new_name[namelen] = '\0'; |
| table[0].procname = new_name; |
| table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO; |
| init_header(&new->header, set->dir.header.root, set, node, table); |
| |
| return new; |
| } |
| |
| static struct ctl_dir *get_subdir(struct ctl_dir *dir, |
| const char *name, int namelen) |
| { |
| struct ctl_table_set *set = dir->header.set; |
| struct ctl_dir *subdir, *new = NULL; |
| int err; |
| |
| spin_lock(&sysctl_lock); |
| subdir = find_subdir(dir, name, namelen); |
| if (!IS_ERR(subdir)) |
| goto found; |
| if (PTR_ERR(subdir) != -ENOENT) |
| goto failed; |
| |
| spin_unlock(&sysctl_lock); |
| new = new_dir(set, name, namelen); |
| spin_lock(&sysctl_lock); |
| subdir = ERR_PTR(-ENOMEM); |
| if (!new) |
| goto failed; |
| |
| subdir = find_subdir(dir, name, namelen); |
| if (!IS_ERR(subdir)) |
| goto found; |
| if (PTR_ERR(subdir) != -ENOENT) |
| goto failed; |
| |
| err = insert_header(dir, &new->header); |
| subdir = ERR_PTR(err); |
| if (err) |
| goto failed; |
| subdir = new; |
| found: |
| subdir->header.nreg++; |
| failed: |
| if (unlikely(IS_ERR(subdir))) { |
| printk(KERN_ERR "sysctl could not get directory: "); |
| sysctl_print_dir(dir); |
| printk(KERN_CONT "/%*.*s %ld\n", |
| namelen, namelen, name, PTR_ERR(subdir)); |
| } |
| drop_sysctl_table(&dir->header); |
| if (new) |
| drop_sysctl_table(&new->header); |
| spin_unlock(&sysctl_lock); |
| return subdir; |
| } |
| |
| static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir) |
| { |
| struct ctl_dir *parent; |
| const char *procname; |
| if (!dir->header.parent) |
| return &set->dir; |
| parent = xlate_dir(set, dir->header.parent); |
| if (IS_ERR(parent)) |
| return parent; |
| procname = dir->header.ctl_table[0].procname; |
| return find_subdir(parent, procname, strlen(procname)); |
| } |
| |
| static int sysctl_follow_link(struct ctl_table_header **phead, |
| struct ctl_table **pentry, struct nsproxy *namespaces) |
| { |
| struct ctl_table_header *head; |
| struct ctl_table_root *root; |
| struct ctl_table_set *set; |
| struct ctl_table *entry; |
| struct ctl_dir *dir; |
| int ret; |
| |
| /* Get out quickly if not a link */ |
| if (!S_ISLNK((*pentry)->mode)) |
| return 0; |
| |
| ret = 0; |
| spin_lock(&sysctl_lock); |
| root = (*pentry)->data; |
| set = lookup_header_set(root, namespaces); |
| dir = xlate_dir(set, (*phead)->parent); |
| if (IS_ERR(dir)) |
| ret = PTR_ERR(dir); |
| else { |
| const char *procname = (*pentry)->procname; |
| head = NULL; |
| entry = find_entry(&head, dir, procname, strlen(procname)); |
| ret = -ENOENT; |
| if (entry && use_table(head)) { |
| unuse_table(*phead); |
| *phead = head; |
| *pentry = entry; |
| ret = 0; |
| } |
| } |
| |
| spin_unlock(&sysctl_lock); |
| return ret; |
| } |
| |
| static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...) |
| { |
| struct va_format vaf; |
| va_list args; |
| |
| va_start(args, fmt); |
| vaf.fmt = fmt; |
| vaf.va = &args; |
| |
| printk(KERN_ERR "sysctl table check failed: %s/%s %pV\n", |
| path, table->procname, &vaf); |
| |
| va_end(args); |
| return -EINVAL; |
| } |
| |
| static int sysctl_check_table(const char *path, struct ctl_table *table) |
| { |
| int err = 0; |
| for (; table->procname; table++) { |
| if (table->child) |
| err = sysctl_err(path, table, "Not a file"); |
| |
| if ((table->proc_handler == proc_dostring) || |
| (table->proc_handler == proc_dointvec) || |
| (table->proc_handler == proc_dointvec_minmax) || |
| (table->proc_handler == proc_dointvec_jiffies) || |
| (table->proc_handler == proc_dointvec_userhz_jiffies) || |
| (table->proc_handler == proc_dointvec_ms_jiffies) || |
| (table->proc_handler == proc_doulongvec_minmax) || |
| (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) { |
| if (!table->data) |
| err = sysctl_err(path, table, "No data"); |
| if (!table->maxlen) |
| err = sysctl_err(path, table, "No maxlen"); |
| } |
| if (!table->proc_handler) |
| err = sysctl_err(path, table, "No proc_handler"); |
| |
| if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode) |
| err = sysctl_err(path, table, "bogus .mode 0%o", |
| table->mode); |
| } |
| return err; |
| } |
| |
| static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table *table, |
| struct ctl_table_root *link_root) |
| { |
| struct ctl_table *link_table, *entry, *link; |
| struct ctl_table_header *links; |
| struct ctl_node *node; |
| char *link_name; |
| int nr_entries, name_bytes; |
| |
| name_bytes = 0; |
| nr_entries = 0; |
| for (entry = table; entry->procname; entry++) { |
| nr_entries++; |
| name_bytes += strlen(entry->procname) + 1; |
| } |
| |
| links = kzalloc(sizeof(struct ctl_table_header) + |
| sizeof(struct ctl_node)*nr_entries + |
| sizeof(struct ctl_table)*(nr_entries + 1) + |
| name_bytes, |
| GFP_KERNEL); |
| |
| if (!links) |
| return NULL; |
| |
| node = (struct ctl_node *)(links + 1); |
| link_table = (struct ctl_table *)(node + nr_entries); |
| link_name = (char *)&link_table[nr_entries + 1]; |
| |
| for (link = link_table, entry = table; entry->procname; link++, entry++) { |
| int len = strlen(entry->procname) + 1; |
| memcpy(link_name, entry->procname, len); |
| link->procname = link_name; |
| link->mode = S_IFLNK|S_IRWXUGO; |
| link->data = link_root; |
| link_name += len; |
| } |
| init_header(links, dir->header.root, dir->header.set, node, link_table); |
| links->nreg = nr_entries; |
| |
| return links; |
| } |
| |
| static bool get_links(struct ctl_dir *dir, |
| struct ctl_table *table, struct ctl_table_root *link_root) |
| { |
| struct ctl_table_header *head; |
| struct ctl_table *entry, *link; |
| |
| /* Are there links available for every entry in table? */ |
| for (entry = table; entry->procname; entry++) { |
| const char *procname = entry->procname; |
| link = find_entry(&head, dir, procname, strlen(procname)); |
| if (!link) |
| return false; |
| if (S_ISDIR(link->mode) && S_ISDIR(entry->mode)) |
| continue; |
| if (S_ISLNK(link->mode) && (link->data == link_root)) |
| continue; |
| return false; |
| } |
| |
| /* The checks passed. Increase the registration count on the links */ |
| for (entry = table; entry->procname; entry++) { |
| const char *procname = entry->procname; |
| link = find_entry(&head, dir, procname, strlen(procname)); |
| head->nreg++; |
| } |
| return true; |
| } |
| |
| static int insert_links(struct ctl_table_header *head) |
| { |
| struct ctl_table_set *root_set = &sysctl_table_root.default_set; |
| struct ctl_dir *core_parent = NULL; |
| struct ctl_table_header *links; |
| int err; |
| |
| if (head->set == root_set) |
| return 0; |
| |
| core_parent = xlate_dir(root_set, head->parent); |
| if (IS_ERR(core_parent)) |
| return 0; |
| |
| if (get_links(core_parent, head->ctl_table, head->root)) |
| return 0; |
| |
| core_parent->header.nreg++; |
| spin_unlock(&sysctl_lock); |
| |
| links = new_links(core_parent, head->ctl_table, head->root); |
| |
| spin_lock(&sysctl_lock); |
| err = -ENOMEM; |
| if (!links) |
| goto out; |
| |
| err = 0; |
| if (get_links(core_parent, head->ctl_table, head->root)) { |
| kfree(links); |
| goto out; |
| } |
| |
| err = insert_header(core_parent, links); |
| if (err) |
| kfree(links); |
| out: |
| drop_sysctl_table(&core_parent->header); |
| return err; |
| } |
| |
| /** |
| * __register_sysctl_table - register a leaf sysctl table |
| * @set: Sysctl tree to register on |
| * @path: The path to the directory the sysctl table is in. |
| * @table: the top-level table structure |
| * |
| * Register a sysctl table hierarchy. @table should be a filled in ctl_table |
| * array. A completely 0 filled entry terminates the table. |
| * |
| * The members of the &struct ctl_table structure are used as follows: |
| * |
| * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not |
| * enter a sysctl file |
| * |
| * data - a pointer to data for use by proc_handler |
| * |
| * maxlen - the maximum size in bytes of the data |
| * |
| * mode - the file permissions for the /proc/sys file |
| * |
| * child - must be %NULL. |
| * |
| * proc_handler - the text handler routine (described below) |
| * |
| * extra1, extra2 - extra pointers usable by the proc handler routines |
| * |
| * Leaf nodes in the sysctl tree will be represented by a single file |
| * under /proc; non-leaf nodes will be represented by directories. |
| * |
| * There must be a proc_handler routine for any terminal nodes. |
| * Several default handlers are available to cover common cases - |
| * |
| * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), |
| * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), |
| * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() |
| * |
| * It is the handler's job to read the input buffer from user memory |
| * and process it. The handler should return 0 on success. |
| * |
| * This routine returns %NULL on a failure to register, and a pointer |
| * to the table header on success. |
| */ |
| struct ctl_table_header *__register_sysctl_table( |
| struct ctl_table_set *set, |
| const char *path, struct ctl_table *table) |
| { |
| struct ctl_table_root *root = set->dir.header.root; |
| struct ctl_table_header *header; |
| const char *name, *nextname; |
| struct ctl_dir *dir; |
| struct ctl_table *entry; |
| struct ctl_node *node; |
| int nr_entries = 0; |
| |
| for (entry = table; entry->procname; entry++) |
| nr_entries++; |
| |
| header = kzalloc(sizeof(struct ctl_table_header) + |
| sizeof(struct ctl_node)*nr_entries, GFP_KERNEL); |
| if (!header) |
| return NULL; |
| |
| node = (struct ctl_node *)(header + 1); |
| init_header(header, root, set, node, table); |
| if (sysctl_check_table(path, table)) |
| goto fail; |
| |
| spin_lock(&sysctl_lock); |
| dir = &set->dir; |
| dir->header.nreg++; |
| spin_unlock(&sysctl_lock); |
| |
| /* Find the directory for the ctl_table */ |
| for (name = path; name; name = nextname) { |
| int namelen; |
| nextname = strchr(name, '/'); |
| if (nextname) { |
| namelen = nextname - name; |
| nextname++; |
| } else { |
| namelen = strlen(name); |
| } |
| if (namelen == 0) |
| continue; |
| |
| dir = get_subdir(dir, name, namelen); |
| if (IS_ERR(dir)) |
| goto fail; |
| } |
| |
| spin_lock(&sysctl_lock); |
| if (insert_header(dir, header)) |
| goto fail_put_dir_locked; |
| |
| drop_sysctl_table(&dir->header); |
| spin_unlock(&sysctl_lock); |
| |
| return header; |
| |
| fail_put_dir_locked: |
| drop_sysctl_table(&dir->header); |
| spin_unlock(&sysctl_lock); |
| fail: |
| kfree(header); |
| dump_stack(); |
| return NULL; |
| } |
| |
| /** |
| * register_sysctl - register a sysctl table |
| * @path: The path to the directory the sysctl table is in. |
| * @table: the table structure |
| * |
| * Register a sysctl table. @table should be a filled in ctl_table |
| * array. A completely 0 filled entry terminates the table. |
| * |
| * See __register_sysctl_table for more details. |
| */ |
| struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) |
| { |
| return __register_sysctl_table(&sysctl_table_root.default_set, |
| path, table); |
| } |
| EXPORT_SYMBOL(register_sysctl); |
| |
| static char *append_path(const char *path, char *pos, const char *name) |
| { |
| int namelen; |
| namelen = strlen(name); |
| if (((pos - path) + namelen + 2) >= PATH_MAX) |
| return NULL; |
| memcpy(pos, name, namelen); |
| pos[namelen] = '/'; |
| pos[namelen + 1] = '\0'; |
| pos += namelen + 1; |
| return pos; |
| } |
| |
| static int count_subheaders(struct ctl_table *table) |
| { |
| int has_files = 0; |
| int nr_subheaders = 0; |
| struct ctl_table *entry; |
| |
| /* special case: no directory and empty directory */ |
| if (!table || !table->procname) |
| return 1; |
| |
| for (entry = table; entry->procname; entry++) { |
| if (entry->child) |
| nr_subheaders += count_subheaders(entry->child); |
| else |
| has_files = 1; |
| } |
| return nr_subheaders + has_files; |
| } |
| |
| static int register_leaf_sysctl_tables(const char *path, char *pos, |
| struct ctl_table_header ***subheader, struct ctl_table_set *set, |
| struct ctl_table *table) |
| { |
| struct ctl_table *ctl_table_arg = NULL; |
| struct ctl_table *entry, *files; |
| int nr_files = 0; |
| int nr_dirs = 0; |
| int err = -ENOMEM; |
| |
| for (entry = table; entry->procname; entry++) { |
| if (entry->child) |
| nr_dirs++; |
| else |
| nr_files++; |
| } |
| |
| files = table; |
| /* If there are mixed files and directories we need a new table */ |
| if (nr_dirs && nr_files) { |
| struct ctl_table *new; |
| files = kzalloc(sizeof(struct ctl_table) * (nr_files + 1), |
| GFP_KERNEL); |
| if (!files) |
| goto out; |
| |
| ctl_table_arg = files; |
| for (new = files, entry = table; entry->procname; entry++) { |
| if (entry->child) |
| continue; |
| *new = *entry; |
| new++; |
| } |
| } |
| |
| /* Register everything except a directory full of subdirectories */ |
| if (nr_files || !nr_dirs) { |
| struct ctl_table_header *header; |
| header = __register_sysctl_table(set, path, files); |
| if (!header) { |
| kfree(ctl_table_arg); |
| goto out; |
| } |
| |
| /* Remember if we need to free the file table */ |
| header->ctl_table_arg = ctl_table_arg; |
| **subheader = header; |
| (*subheader)++; |
| } |
| |
| /* Recurse into the subdirectories. */ |
| for (entry = table; entry->procname; entry++) { |
| char *child_pos; |
| |
| if (!entry->child) |
| continue; |
| |
| err = -ENAMETOOLONG; |
| child_pos = append_path(path, pos, entry->procname); |
| if (!child_pos) |
| goto out; |
| |
| err = register_leaf_sysctl_tables(path, child_pos, subheader, |
| set, entry->child); |
| pos[0] = '\0'; |
| if (err) |
| goto out; |
| } |
| err = 0; |
| out: |
| /* On failure our caller will unregister all registered subheaders */ |
| return err; |
| } |
| |
| /** |
| * __register_sysctl_paths - register a sysctl table hierarchy |
| * @set: Sysctl tree to register on |
| * @path: The path to the directory the sysctl table is in. |
| * @table: the top-level table structure |
| * |
| * Register a sysctl table hierarchy. @table should be a filled in ctl_table |
| * array. A completely 0 filled entry terminates the table. |
| * |
| * See __register_sysctl_table for more details. |
| */ |
| struct ctl_table_header *__register_sysctl_paths( |
| struct ctl_table_set *set, |
| const struct ctl_path *path, struct ctl_table *table) |
| { |
| struct ctl_table *ctl_table_arg = table; |
| int nr_subheaders = count_subheaders(table); |
| struct ctl_table_header *header = NULL, **subheaders, **subheader; |
| const struct ctl_path *component; |
| char *new_path, *pos; |
| |
| pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); |
| if (!new_path) |
| return NULL; |
| |
| pos[0] = '\0'; |
| for (component = path; component->procname; component++) { |
| pos = append_path(new_path, pos, component->procname); |
| if (!pos) |
| goto out; |
| } |
| while (table->procname && table->child && !table[1].procname) { |
| pos = append_path(new_path, pos, table->procname); |
| if (!pos) |
| goto out; |
| table = table->child; |
| } |
| if (nr_subheaders == 1) { |
| header = __register_sysctl_table(set, new_path, table); |
| if (header) |
| header->ctl_table_arg = ctl_table_arg; |
| } else { |
| header = kzalloc(sizeof(*header) + |
| sizeof(*subheaders)*nr_subheaders, GFP_KERNEL); |
| if (!header) |
| goto out; |
| |
| subheaders = (struct ctl_table_header **) (header + 1); |
| subheader = subheaders; |
| header->ctl_table_arg = ctl_table_arg; |
| |
| if (register_leaf_sysctl_tables(new_path, pos, &subheader, |
| set, table)) |
| goto err_register_leaves; |
| } |
| |
| out: |
| kfree(new_path); |
| return header; |
| |
| err_register_leaves: |
| while (subheader > subheaders) { |
| struct ctl_table_header *subh = *(--subheader); |
| struct ctl_table *table = subh->ctl_table_arg; |
| unregister_sysctl_table(subh); |
| kfree(table); |
| } |
| kfree(header); |
| header = NULL; |
| goto out; |
| } |
| |
| /** |
| * register_sysctl_table_path - register a sysctl table hierarchy |
| * @path: The path to the directory the sysctl table is in. |
| * @table: the top-level table structure |
| * |
| * Register a sysctl table hierarchy. @table should be a filled in ctl_table |
| * array. A completely 0 filled entry terminates the table. |
| * |
| * See __register_sysctl_paths for more details. |
| */ |
| struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, |
| struct ctl_table *table) |
| { |
| return __register_sysctl_paths(&sysctl_table_root.default_set, |
| path, table); |
| } |
| EXPORT_SYMBOL(register_sysctl_paths); |
| |
| /** |
| * register_sysctl_table - register a sysctl table hierarchy |
| * @table: the top-level table structure |
| * |
| * Register a sysctl table hierarchy. @table should be a filled in ctl_table |
| * array. A completely 0 filled entry terminates the table. |
| * |
| * See register_sysctl_paths for more details. |
| */ |
| struct ctl_table_header *register_sysctl_table(struct ctl_table *table) |
| { |
| static const struct ctl_path null_path[] = { {} }; |
| |
| return register_sysctl_paths(null_path, table); |
| } |
| EXPORT_SYMBOL(register_sysctl_table); |
| |
| static void put_links(struct ctl_table_header *header) |
| { |
| struct ctl_table_set *root_set = &sysctl_table_root.default_set; |
| struct ctl_table_root *root = header->root; |
| struct ctl_dir *parent = header->parent; |
| struct ctl_dir *core_parent; |
| struct ctl_table *entry; |
| |
| if (header->set == root_set) |
| return; |
| |
| core_parent = xlate_dir(root_set, parent); |
| if (IS_ERR(core_parent)) |
| return; |
| |
| for (entry = header->ctl_table; entry->procname; entry++) { |
| struct ctl_table_header *link_head; |
| struct ctl_table *link; |
| const char *name = entry->procname; |
| |
| link = find_entry(&link_head, core_parent, name, strlen(name)); |
| if (link && |
| ((S_ISDIR(link->mode) && S_ISDIR(entry->mode)) || |
| (S_ISLNK(link->mode) && (link->data == root)))) { |
| drop_sysctl_table(link_head); |
| } |
| else { |
| printk(KERN_ERR "sysctl link missing during unregister: "); |
| sysctl_print_dir(parent); |
| printk(KERN_CONT "/%s\n", name); |
| } |
| } |
| } |
| |
| static void drop_sysctl_table(struct ctl_table_header *header) |
| { |
| struct ctl_dir *parent = header->parent; |
| |
| if (--header->nreg) |
| return; |
| |
| put_links(header); |
| start_unregistering(header); |
| if (!--header->count) |
| kfree_rcu(header, rcu); |
| |
| if (parent) |
| drop_sysctl_table(&parent->header); |
| } |
| |
| /** |
| * unregister_sysctl_table - unregister a sysctl table hierarchy |
| * @header: the header returned from register_sysctl_table |
| * |
| * Unregisters the sysctl table and all children. proc entries may not |
| * actually be removed until they are no longer used by anyone. |
| */ |
| void unregister_sysctl_table(struct ctl_table_header * header) |
| { |
| int nr_subheaders; |
| might_sleep(); |
| |
| if (header == NULL) |
| return; |
| |
| nr_subheaders = count_subheaders(header->ctl_table_arg); |
| if (unlikely(nr_subheaders > 1)) { |
| struct ctl_table_header **subheaders; |
| int i; |
| |
| subheaders = (struct ctl_table_header **)(header + 1); |
| for (i = nr_subheaders -1; i >= 0; i--) { |
| struct ctl_table_header *subh = subheaders[i]; |
| struct ctl_table *table = subh->ctl_table_arg; |
| unregister_sysctl_table(subh); |
| kfree(table); |
| } |
| kfree(header); |
| return; |
| } |
| |
| spin_lock(&sysctl_lock); |
| drop_sysctl_table(header); |
| spin_unlock(&sysctl_lock); |
| } |
| EXPORT_SYMBOL(unregister_sysctl_table); |
| |
| void setup_sysctl_set(struct ctl_table_set *set, |
| struct ctl_table_root *root, |
| int (*is_seen)(struct ctl_table_set *)) |
| { |
| memset(set, 0, sizeof(*set)); |
| set->is_seen = is_seen; |
| init_header(&set->dir.header, root, set, NULL, root_table); |
| } |
| |
| void retire_sysctl_set(struct ctl_table_set *set) |
| { |
| WARN_ON(!RB_EMPTY_ROOT(&set->dir.root)); |
| } |
| |
| int __init proc_sys_init(void) |
| { |
| struct proc_dir_entry *proc_sys_root; |
| |
| proc_sys_root = proc_mkdir("sys", NULL); |
| proc_sys_root->proc_iops = &proc_sys_dir_operations; |
| proc_sys_root->proc_fops = &proc_sys_dir_file_operations; |
| proc_sys_root->nlink = 0; |
| |
| return sysctl_init(); |
| } |