177b14db5SEric W. Biederman /* 277b14db5SEric W. Biederman * /proc/sys support 377b14db5SEric W. Biederman */ 41e0edd3fSAlexey Dobriyan #include <linux/init.h> 577b14db5SEric W. Biederman #include <linux/sysctl.h> 6f1ecf068SLucas De Marchi #include <linux/poll.h> 777b14db5SEric W. Biederman #include <linux/proc_fs.h> 877b14db5SEric W. Biederman #include <linux/security.h> 934286d66SNick Piggin #include <linux/namei.h> 101f87f0b5SEric W. Biederman #include <linux/module.h> 1177b14db5SEric W. Biederman #include "internal.h" 1277b14db5SEric W. Biederman 13d72f71ebSAl Viro static const struct dentry_operations proc_sys_dentry_operations; 1477b14db5SEric W. Biederman static const struct file_operations proc_sys_file_operations; 1503a44825SJan Engelhardt static const struct inode_operations proc_sys_inode_operations; 169043476fSAl Viro static const struct file_operations proc_sys_dir_file_operations; 179043476fSAl Viro static const struct inode_operations proc_sys_dir_operations; 1877b14db5SEric W. Biederman 19f1ecf068SLucas De Marchi void proc_sys_poll_notify(struct ctl_table_poll *poll) 20f1ecf068SLucas De Marchi { 21f1ecf068SLucas De Marchi if (!poll) 22f1ecf068SLucas De Marchi return; 23f1ecf068SLucas De Marchi 24f1ecf068SLucas De Marchi atomic_inc(&poll->event); 25f1ecf068SLucas De Marchi wake_up_interruptible(&poll->wait); 26f1ecf068SLucas De Marchi } 27f1ecf068SLucas De Marchi 281f87f0b5SEric W. Biederman static struct ctl_table root_table[1]; 291f87f0b5SEric W. Biederman static struct ctl_table_root sysctl_table_root; 301f87f0b5SEric W. Biederman static struct ctl_table_header root_table_header = { 311f87f0b5SEric W. Biederman {{.count = 1, 32938aaa4fSEric W. Biederman .nreg = 1, 331f87f0b5SEric W. Biederman .ctl_table = root_table, 341f87f0b5SEric W. Biederman .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}}, 351f87f0b5SEric W. Biederman .root = &sysctl_table_root, 361f87f0b5SEric W. Biederman .set = &sysctl_table_root.default_set, 371f87f0b5SEric W. Biederman }; 381f87f0b5SEric W. Biederman static struct ctl_table_root sysctl_table_root = { 391f87f0b5SEric W. Biederman .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list), 401f87f0b5SEric W. Biederman .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry), 411f87f0b5SEric W. Biederman }; 421f87f0b5SEric W. Biederman 431f87f0b5SEric W. Biederman static DEFINE_SPINLOCK(sysctl_lock); 441f87f0b5SEric W. Biederman 45e0d04529SEric W. Biederman static void init_header(struct ctl_table_header *head, 46e0d04529SEric W. Biederman struct ctl_table_root *root, struct ctl_table_set *set, 47e0d04529SEric W. Biederman struct ctl_table *table) 48e0d04529SEric W. Biederman { 49e0d04529SEric W. Biederman head->ctl_table_arg = table; 50e0d04529SEric W. Biederman INIT_LIST_HEAD(&head->ctl_entry); 51e0d04529SEric W. Biederman head->used = 0; 52e0d04529SEric W. Biederman head->count = 1; 53e0d04529SEric W. Biederman head->nreg = 1; 54e0d04529SEric W. Biederman head->unregistering = NULL; 55e0d04529SEric W. Biederman head->root = root; 56e0d04529SEric W. Biederman head->set = set; 57e0d04529SEric W. Biederman head->parent = NULL; 58e0d04529SEric W. Biederman } 59e0d04529SEric W. Biederman 608425d6aaSEric W. Biederman static void erase_header(struct ctl_table_header *head) 618425d6aaSEric W. Biederman { 628425d6aaSEric W. Biederman list_del_init(&head->ctl_entry); 638425d6aaSEric W. Biederman } 648425d6aaSEric W. Biederman 658425d6aaSEric W. Biederman static void insert_header(struct ctl_table_header *header) 668425d6aaSEric W. Biederman { 678425d6aaSEric W. Biederman header->parent->count++; 688425d6aaSEric W. Biederman list_add_tail(&header->ctl_entry, &header->set->list); 698425d6aaSEric W. Biederman } 708425d6aaSEric W. Biederman 711f87f0b5SEric W. Biederman /* called under sysctl_lock */ 721f87f0b5SEric W. Biederman static int use_table(struct ctl_table_header *p) 731f87f0b5SEric W. Biederman { 741f87f0b5SEric W. Biederman if (unlikely(p->unregistering)) 751f87f0b5SEric W. Biederman return 0; 761f87f0b5SEric W. Biederman p->used++; 771f87f0b5SEric W. Biederman return 1; 781f87f0b5SEric W. Biederman } 791f87f0b5SEric W. Biederman 801f87f0b5SEric W. Biederman /* called under sysctl_lock */ 811f87f0b5SEric W. Biederman static void unuse_table(struct ctl_table_header *p) 821f87f0b5SEric W. Biederman { 831f87f0b5SEric W. Biederman if (!--p->used) 841f87f0b5SEric W. Biederman if (unlikely(p->unregistering)) 851f87f0b5SEric W. Biederman complete(p->unregistering); 861f87f0b5SEric W. Biederman } 871f87f0b5SEric W. Biederman 881f87f0b5SEric W. Biederman /* called under sysctl_lock, will reacquire if has to wait */ 891f87f0b5SEric W. Biederman static void start_unregistering(struct ctl_table_header *p) 901f87f0b5SEric W. Biederman { 911f87f0b5SEric W. Biederman /* 921f87f0b5SEric W. Biederman * if p->used is 0, nobody will ever touch that entry again; 931f87f0b5SEric W. Biederman * we'll eliminate all paths to it before dropping sysctl_lock 941f87f0b5SEric W. Biederman */ 951f87f0b5SEric W. Biederman if (unlikely(p->used)) { 961f87f0b5SEric W. Biederman struct completion wait; 971f87f0b5SEric W. Biederman init_completion(&wait); 981f87f0b5SEric W. Biederman p->unregistering = &wait; 991f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 1001f87f0b5SEric W. Biederman wait_for_completion(&wait); 1011f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1021f87f0b5SEric W. Biederman } else { 1031f87f0b5SEric W. Biederman /* anything non-NULL; we'll never dereference it */ 1041f87f0b5SEric W. Biederman p->unregistering = ERR_PTR(-EINVAL); 1051f87f0b5SEric W. Biederman } 1061f87f0b5SEric W. Biederman /* 1071f87f0b5SEric W. Biederman * do not remove from the list until nobody holds it; walking the 1081f87f0b5SEric W. Biederman * list in do_sysctl() relies on that. 1091f87f0b5SEric W. Biederman */ 1108425d6aaSEric W. Biederman erase_header(p); 1111f87f0b5SEric W. Biederman } 1121f87f0b5SEric W. Biederman 1131f87f0b5SEric W. Biederman static void sysctl_head_get(struct ctl_table_header *head) 1141f87f0b5SEric W. Biederman { 1151f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1161f87f0b5SEric W. Biederman head->count++; 1171f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 1181f87f0b5SEric W. Biederman } 1191f87f0b5SEric W. Biederman 1201f87f0b5SEric W. Biederman void sysctl_head_put(struct ctl_table_header *head) 1211f87f0b5SEric W. Biederman { 1221f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1231f87f0b5SEric W. Biederman if (!--head->count) 1241f87f0b5SEric W. Biederman kfree_rcu(head, rcu); 1251f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 1261f87f0b5SEric W. Biederman } 1271f87f0b5SEric W. Biederman 1281f87f0b5SEric W. Biederman static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) 1291f87f0b5SEric W. Biederman { 1301f87f0b5SEric W. Biederman if (!head) 1311f87f0b5SEric W. Biederman BUG(); 1321f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1331f87f0b5SEric W. Biederman if (!use_table(head)) 1341f87f0b5SEric W. Biederman head = ERR_PTR(-ENOENT); 1351f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 1361f87f0b5SEric W. Biederman return head; 1371f87f0b5SEric W. Biederman } 1381f87f0b5SEric W. Biederman 1391f87f0b5SEric W. Biederman static void sysctl_head_finish(struct ctl_table_header *head) 1401f87f0b5SEric W. Biederman { 1411f87f0b5SEric W. Biederman if (!head) 1421f87f0b5SEric W. Biederman return; 1431f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1441f87f0b5SEric W. Biederman unuse_table(head); 1451f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 1461f87f0b5SEric W. Biederman } 1471f87f0b5SEric W. Biederman 1481f87f0b5SEric W. Biederman static struct ctl_table_set * 1491f87f0b5SEric W. Biederman lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces) 1501f87f0b5SEric W. Biederman { 1511f87f0b5SEric W. Biederman struct ctl_table_set *set = &root->default_set; 1521f87f0b5SEric W. Biederman if (root->lookup) 1531f87f0b5SEric W. Biederman set = root->lookup(root, namespaces); 1541f87f0b5SEric W. Biederman return set; 1551f87f0b5SEric W. Biederman } 1561f87f0b5SEric W. Biederman 1571f87f0b5SEric W. Biederman static struct list_head * 1581f87f0b5SEric W. Biederman lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces) 1591f87f0b5SEric W. Biederman { 1601f87f0b5SEric W. Biederman struct ctl_table_set *set = lookup_header_set(root, namespaces); 1611f87f0b5SEric W. Biederman return &set->list; 1621f87f0b5SEric W. Biederman } 1631f87f0b5SEric W. Biederman 1641f87f0b5SEric W. Biederman static struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces, 1651f87f0b5SEric W. Biederman struct ctl_table_header *prev) 1661f87f0b5SEric W. Biederman { 1671f87f0b5SEric W. Biederman struct ctl_table_root *root; 1681f87f0b5SEric W. Biederman struct list_head *header_list; 1691f87f0b5SEric W. Biederman struct ctl_table_header *head; 1701f87f0b5SEric W. Biederman struct list_head *tmp; 1711f87f0b5SEric W. Biederman 1721f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1731f87f0b5SEric W. Biederman if (prev) { 1741f87f0b5SEric W. Biederman head = prev; 1751f87f0b5SEric W. Biederman tmp = &prev->ctl_entry; 1761f87f0b5SEric W. Biederman unuse_table(prev); 1771f87f0b5SEric W. Biederman goto next; 1781f87f0b5SEric W. Biederman } 1791f87f0b5SEric W. Biederman tmp = &root_table_header.ctl_entry; 1801f87f0b5SEric W. Biederman for (;;) { 1811f87f0b5SEric W. Biederman head = list_entry(tmp, struct ctl_table_header, ctl_entry); 1821f87f0b5SEric W. Biederman 1831f87f0b5SEric W. Biederman if (!use_table(head)) 1841f87f0b5SEric W. Biederman goto next; 1851f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 1861f87f0b5SEric W. Biederman return head; 1871f87f0b5SEric W. Biederman next: 1881f87f0b5SEric W. Biederman root = head->root; 1891f87f0b5SEric W. Biederman tmp = tmp->next; 1901f87f0b5SEric W. Biederman header_list = lookup_header_list(root, namespaces); 1911f87f0b5SEric W. Biederman if (tmp != header_list) 1921f87f0b5SEric W. Biederman continue; 1931f87f0b5SEric W. Biederman 1941f87f0b5SEric W. Biederman do { 1951f87f0b5SEric W. Biederman root = list_entry(root->root_list.next, 1961f87f0b5SEric W. Biederman struct ctl_table_root, root_list); 1971f87f0b5SEric W. Biederman if (root == &sysctl_table_root) 1981f87f0b5SEric W. Biederman goto out; 1991f87f0b5SEric W. Biederman header_list = lookup_header_list(root, namespaces); 2001f87f0b5SEric W. Biederman } while (list_empty(header_list)); 2011f87f0b5SEric W. Biederman tmp = header_list->next; 2021f87f0b5SEric W. Biederman } 2031f87f0b5SEric W. Biederman out: 2041f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2051f87f0b5SEric W. Biederman return NULL; 2061f87f0b5SEric W. Biederman } 2071f87f0b5SEric W. Biederman 2081f87f0b5SEric W. Biederman static struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev) 2091f87f0b5SEric W. Biederman { 2101f87f0b5SEric W. Biederman return __sysctl_head_next(current->nsproxy, prev); 2111f87f0b5SEric W. Biederman } 2121f87f0b5SEric W. Biederman 2131f87f0b5SEric W. Biederman void register_sysctl_root(struct ctl_table_root *root) 2141f87f0b5SEric W. Biederman { 2151f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 2161f87f0b5SEric W. Biederman list_add_tail(&root->root_list, &sysctl_table_root.root_list); 2171f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2181f87f0b5SEric W. Biederman } 2191f87f0b5SEric W. Biederman 2201f87f0b5SEric W. Biederman /* 2211f87f0b5SEric W. Biederman * sysctl_perm does NOT grant the superuser all rights automatically, because 2221f87f0b5SEric W. Biederman * some sysctl variables are readonly even to root. 2231f87f0b5SEric W. Biederman */ 2241f87f0b5SEric W. Biederman 2251f87f0b5SEric W. Biederman static int test_perm(int mode, int op) 2261f87f0b5SEric W. Biederman { 2271f87f0b5SEric W. Biederman if (!current_euid()) 2281f87f0b5SEric W. Biederman mode >>= 6; 2291f87f0b5SEric W. Biederman else if (in_egroup_p(0)) 2301f87f0b5SEric W. Biederman mode >>= 3; 2311f87f0b5SEric W. Biederman if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) 2321f87f0b5SEric W. Biederman return 0; 2331f87f0b5SEric W. Biederman return -EACCES; 2341f87f0b5SEric W. Biederman } 2351f87f0b5SEric W. Biederman 2361f87f0b5SEric W. Biederman static int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op) 2371f87f0b5SEric W. Biederman { 2381f87f0b5SEric W. Biederman int mode; 2391f87f0b5SEric W. Biederman 2401f87f0b5SEric W. Biederman if (root->permissions) 2411f87f0b5SEric W. Biederman mode = root->permissions(root, current->nsproxy, table); 2421f87f0b5SEric W. Biederman else 2431f87f0b5SEric W. Biederman mode = table->mode; 2441f87f0b5SEric W. Biederman 2451f87f0b5SEric W. Biederman return test_perm(mode, op); 2461f87f0b5SEric W. Biederman } 2471f87f0b5SEric W. Biederman 2489043476fSAl Viro static struct inode *proc_sys_make_inode(struct super_block *sb, 2499043476fSAl Viro struct ctl_table_header *head, struct ctl_table *table) 25077b14db5SEric W. Biederman { 25177b14db5SEric W. Biederman struct inode *inode; 2529043476fSAl Viro struct proc_inode *ei; 25377b14db5SEric W. Biederman 2549043476fSAl Viro inode = new_inode(sb); 25577b14db5SEric W. Biederman if (!inode) 25677b14db5SEric W. Biederman goto out; 25777b14db5SEric W. Biederman 25885fe4025SChristoph Hellwig inode->i_ino = get_next_ino(); 25985fe4025SChristoph Hellwig 2609043476fSAl Viro sysctl_head_get(head); 26177b14db5SEric W. Biederman ei = PROC_I(inode); 2629043476fSAl Viro ei->sysctl = head; 2639043476fSAl Viro ei->sysctl_entry = table; 2649043476fSAl Viro 26577b14db5SEric W. Biederman inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2669043476fSAl Viro inode->i_mode = table->mode; 2679043476fSAl Viro if (!table->child) { 2689043476fSAl Viro inode->i_mode |= S_IFREG; 26977b14db5SEric W. Biederman inode->i_op = &proc_sys_inode_operations; 27077b14db5SEric W. Biederman inode->i_fop = &proc_sys_file_operations; 2719043476fSAl Viro } else { 2729043476fSAl Viro inode->i_mode |= S_IFDIR; 2739043476fSAl Viro inode->i_op = &proc_sys_dir_operations; 2749043476fSAl Viro inode->i_fop = &proc_sys_dir_file_operations; 2759043476fSAl Viro } 27677b14db5SEric W. Biederman out: 27777b14db5SEric W. Biederman return inode; 27877b14db5SEric W. Biederman } 27977b14db5SEric W. Biederman 2809043476fSAl Viro static struct ctl_table *find_in_table(struct ctl_table *p, struct qstr *name) 28177b14db5SEric W. Biederman { 2822315ffa0SEric W. Biederman for ( ; p->procname; p++) { 28336885d7bSLucas De Marchi if (strlen(p->procname) != name->len) 28477b14db5SEric W. Biederman continue; 28577b14db5SEric W. Biederman 28636885d7bSLucas De Marchi if (memcmp(p->procname, name->name, name->len) != 0) 28777b14db5SEric W. Biederman continue; 28877b14db5SEric W. Biederman 28977b14db5SEric W. Biederman /* I have a match */ 2909043476fSAl Viro return p; 29177b14db5SEric W. Biederman } 29277b14db5SEric W. Biederman return NULL; 29377b14db5SEric W. Biederman } 29477b14db5SEric W. Biederman 29581324364SAdrian Bunk static struct ctl_table_header *grab_header(struct inode *inode) 29677b14db5SEric W. Biederman { 2973cc3e046SEric W. Biederman struct ctl_table_header *head = PROC_I(inode)->sysctl; 2983cc3e046SEric W. Biederman if (!head) 2993cc3e046SEric W. Biederman head = &root_table_header; 3003cc3e046SEric W. Biederman return sysctl_head_grab(head); 30177b14db5SEric W. Biederman } 30277b14db5SEric W. Biederman 30377b14db5SEric W. Biederman static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, 30477b14db5SEric W. Biederman struct nameidata *nd) 30577b14db5SEric W. Biederman { 3069043476fSAl Viro struct ctl_table_header *head = grab_header(dir); 3079043476fSAl Viro struct ctl_table *table = PROC_I(dir)->sysctl_entry; 3089043476fSAl Viro struct ctl_table_header *h = NULL; 3099043476fSAl Viro struct qstr *name = &dentry->d_name; 3109043476fSAl Viro struct ctl_table *p; 31177b14db5SEric W. Biederman struct inode *inode; 3129043476fSAl Viro struct dentry *err = ERR_PTR(-ENOENT); 31377b14db5SEric W. Biederman 3149043476fSAl Viro if (IS_ERR(head)) 3159043476fSAl Viro return ERR_CAST(head); 3169043476fSAl Viro 3179043476fSAl Viro if (table && !table->child) { 3189043476fSAl Viro WARN_ON(1); 3199043476fSAl Viro goto out; 3209043476fSAl Viro } 3219043476fSAl Viro 3229043476fSAl Viro table = table ? table->child : head->ctl_table; 3239043476fSAl Viro 3249043476fSAl Viro p = find_in_table(table, name); 3259043476fSAl Viro if (!p) { 3269043476fSAl Viro for (h = sysctl_head_next(NULL); h; h = sysctl_head_next(h)) { 3279043476fSAl Viro if (h->attached_to != table) 3289043476fSAl Viro continue; 3299043476fSAl Viro p = find_in_table(h->attached_by, name); 3309043476fSAl Viro if (p) 3319043476fSAl Viro break; 3329043476fSAl Viro } 3339043476fSAl Viro } 3349043476fSAl Viro 3359043476fSAl Viro if (!p) 33677b14db5SEric W. Biederman goto out; 33777b14db5SEric W. Biederman 33877b14db5SEric W. Biederman err = ERR_PTR(-ENOMEM); 3399043476fSAl Viro inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); 3409043476fSAl Viro if (h) 3419043476fSAl Viro sysctl_head_finish(h); 3429043476fSAl Viro 34377b14db5SEric W. Biederman if (!inode) 34477b14db5SEric W. Biederman goto out; 34577b14db5SEric W. Biederman 34677b14db5SEric W. Biederman err = NULL; 347fb045adbSNick Piggin d_set_d_op(dentry, &proc_sys_dentry_operations); 34877b14db5SEric W. Biederman d_add(dentry, inode); 34977b14db5SEric W. Biederman 35077b14db5SEric W. Biederman out: 35177b14db5SEric W. Biederman sysctl_head_finish(head); 35277b14db5SEric W. Biederman return err; 35377b14db5SEric W. Biederman } 35477b14db5SEric W. Biederman 3557708bfb1SPavel Emelyanov static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf, 3567708bfb1SPavel Emelyanov size_t count, loff_t *ppos, int write) 35777b14db5SEric W. Biederman { 3589043476fSAl Viro struct inode *inode = filp->f_path.dentry->d_inode; 3599043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 3609043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 3612a2da53bSDavid Howells ssize_t error; 3622a2da53bSDavid Howells size_t res; 36377b14db5SEric W. Biederman 3649043476fSAl Viro if (IS_ERR(head)) 3659043476fSAl Viro return PTR_ERR(head); 36677b14db5SEric W. Biederman 36777b14db5SEric W. Biederman /* 36877b14db5SEric W. Biederman * At this point we know that the sysctl was not unregistered 36977b14db5SEric W. Biederman * and won't be until we finish. 37077b14db5SEric W. Biederman */ 37177b14db5SEric W. Biederman error = -EPERM; 372d7321cd6SPavel Emelyanov if (sysctl_perm(head->root, table, write ? MAY_WRITE : MAY_READ)) 37377b14db5SEric W. Biederman goto out; 37477b14db5SEric W. Biederman 3759043476fSAl Viro /* if that can happen at all, it should be -EINVAL, not -EISDIR */ 3769043476fSAl Viro error = -EINVAL; 3779043476fSAl Viro if (!table->proc_handler) 3789043476fSAl Viro goto out; 3799043476fSAl Viro 38077b14db5SEric W. Biederman /* careful: calling conventions are nasty here */ 38177b14db5SEric W. Biederman res = count; 3828d65af78SAlexey Dobriyan error = table->proc_handler(table, write, buf, &res, ppos); 38377b14db5SEric W. Biederman if (!error) 38477b14db5SEric W. Biederman error = res; 38577b14db5SEric W. Biederman out: 38677b14db5SEric W. Biederman sysctl_head_finish(head); 38777b14db5SEric W. Biederman 38877b14db5SEric W. Biederman return error; 38977b14db5SEric W. Biederman } 39077b14db5SEric W. Biederman 3917708bfb1SPavel Emelyanov static ssize_t proc_sys_read(struct file *filp, char __user *buf, 3927708bfb1SPavel Emelyanov size_t count, loff_t *ppos) 3937708bfb1SPavel Emelyanov { 3947708bfb1SPavel Emelyanov return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0); 3957708bfb1SPavel Emelyanov } 3967708bfb1SPavel Emelyanov 39777b14db5SEric W. Biederman static ssize_t proc_sys_write(struct file *filp, const char __user *buf, 39877b14db5SEric W. Biederman size_t count, loff_t *ppos) 39977b14db5SEric W. Biederman { 4007708bfb1SPavel Emelyanov return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1); 40177b14db5SEric W. Biederman } 40277b14db5SEric W. Biederman 403f1ecf068SLucas De Marchi static int proc_sys_open(struct inode *inode, struct file *filp) 404f1ecf068SLucas De Marchi { 405f1ecf068SLucas De Marchi struct ctl_table *table = PROC_I(inode)->sysctl_entry; 406f1ecf068SLucas De Marchi 407f1ecf068SLucas De Marchi if (table->poll) 408f1ecf068SLucas De Marchi filp->private_data = proc_sys_poll_event(table->poll); 409f1ecf068SLucas De Marchi 410f1ecf068SLucas De Marchi return 0; 411f1ecf068SLucas De Marchi } 412f1ecf068SLucas De Marchi 413f1ecf068SLucas De Marchi static unsigned int proc_sys_poll(struct file *filp, poll_table *wait) 414f1ecf068SLucas De Marchi { 415f1ecf068SLucas De Marchi struct inode *inode = filp->f_path.dentry->d_inode; 416f1ecf068SLucas De Marchi struct ctl_table *table = PROC_I(inode)->sysctl_entry; 417f1ecf068SLucas De Marchi unsigned long event = (unsigned long)filp->private_data; 418f1ecf068SLucas De Marchi unsigned int ret = DEFAULT_POLLMASK; 419f1ecf068SLucas De Marchi 420f1ecf068SLucas De Marchi if (!table->proc_handler) 421f1ecf068SLucas De Marchi goto out; 422f1ecf068SLucas De Marchi 423f1ecf068SLucas De Marchi if (!table->poll) 424f1ecf068SLucas De Marchi goto out; 425f1ecf068SLucas De Marchi 426f1ecf068SLucas De Marchi poll_wait(filp, &table->poll->wait, wait); 427f1ecf068SLucas De Marchi 428f1ecf068SLucas De Marchi if (event != atomic_read(&table->poll->event)) { 429f1ecf068SLucas De Marchi filp->private_data = proc_sys_poll_event(table->poll); 430f1ecf068SLucas De Marchi ret = POLLIN | POLLRDNORM | POLLERR | POLLPRI; 431f1ecf068SLucas De Marchi } 432f1ecf068SLucas De Marchi 433f1ecf068SLucas De Marchi out: 434f1ecf068SLucas De Marchi return ret; 435f1ecf068SLucas De Marchi } 43677b14db5SEric W. Biederman 43777b14db5SEric W. Biederman static int proc_sys_fill_cache(struct file *filp, void *dirent, 4389043476fSAl Viro filldir_t filldir, 4399043476fSAl Viro struct ctl_table_header *head, 4409043476fSAl Viro struct ctl_table *table) 44177b14db5SEric W. Biederman { 44277b14db5SEric W. Biederman struct dentry *child, *dir = filp->f_path.dentry; 44377b14db5SEric W. Biederman struct inode *inode; 44477b14db5SEric W. Biederman struct qstr qname; 44577b14db5SEric W. Biederman ino_t ino = 0; 44677b14db5SEric W. Biederman unsigned type = DT_UNKNOWN; 44777b14db5SEric W. Biederman 44877b14db5SEric W. Biederman qname.name = table->procname; 44977b14db5SEric W. Biederman qname.len = strlen(table->procname); 45077b14db5SEric W. Biederman qname.hash = full_name_hash(qname.name, qname.len); 45177b14db5SEric W. Biederman 45277b14db5SEric W. Biederman child = d_lookup(dir, &qname); 45377b14db5SEric W. Biederman if (!child) { 4549043476fSAl Viro child = d_alloc(dir, &qname); 4559043476fSAl Viro if (child) { 4569043476fSAl Viro inode = proc_sys_make_inode(dir->d_sb, head, table); 4579043476fSAl Viro if (!inode) { 4589043476fSAl Viro dput(child); 4599043476fSAl Viro return -ENOMEM; 4609043476fSAl Viro } else { 461fb045adbSNick Piggin d_set_d_op(child, &proc_sys_dentry_operations); 4629043476fSAl Viro d_add(child, inode); 46377b14db5SEric W. Biederman } 4649043476fSAl Viro } else { 4659043476fSAl Viro return -ENOMEM; 46677b14db5SEric W. Biederman } 46777b14db5SEric W. Biederman } 46877b14db5SEric W. Biederman inode = child->d_inode; 46977b14db5SEric W. Biederman ino = inode->i_ino; 47077b14db5SEric W. Biederman type = inode->i_mode >> 12; 47177b14db5SEric W. Biederman dput(child); 4729043476fSAl Viro return !!filldir(dirent, qname.name, qname.len, filp->f_pos, ino, type); 4739043476fSAl Viro } 4749043476fSAl Viro 4759043476fSAl Viro static int scan(struct ctl_table_header *head, ctl_table *table, 4769043476fSAl Viro unsigned long *pos, struct file *file, 4779043476fSAl Viro void *dirent, filldir_t filldir) 4789043476fSAl Viro { 4799043476fSAl Viro 4802315ffa0SEric W. Biederman for (; table->procname; table++, (*pos)++) { 4819043476fSAl Viro int res; 4829043476fSAl Viro 4839043476fSAl Viro if (*pos < file->f_pos) 4849043476fSAl Viro continue; 4859043476fSAl Viro 4869043476fSAl Viro res = proc_sys_fill_cache(file, dirent, filldir, head, table); 4879043476fSAl Viro if (res) 4889043476fSAl Viro return res; 4899043476fSAl Viro 4909043476fSAl Viro file->f_pos = *pos + 1; 4919043476fSAl Viro } 4929043476fSAl Viro return 0; 49377b14db5SEric W. Biederman } 49477b14db5SEric W. Biederman 49577b14db5SEric W. Biederman static int proc_sys_readdir(struct file *filp, void *dirent, filldir_t filldir) 49677b14db5SEric W. Biederman { 4979043476fSAl Viro struct dentry *dentry = filp->f_path.dentry; 49877b14db5SEric W. Biederman struct inode *inode = dentry->d_inode; 4999043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 5009043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 5019043476fSAl Viro struct ctl_table_header *h = NULL; 50277b14db5SEric W. Biederman unsigned long pos; 5039043476fSAl Viro int ret = -EINVAL; 50477b14db5SEric W. Biederman 5059043476fSAl Viro if (IS_ERR(head)) 5069043476fSAl Viro return PTR_ERR(head); 5079043476fSAl Viro 5089043476fSAl Viro if (table && !table->child) { 5099043476fSAl Viro WARN_ON(1); 51077b14db5SEric W. Biederman goto out; 5119043476fSAl Viro } 5129043476fSAl Viro 5139043476fSAl Viro table = table ? table->child : head->ctl_table; 51477b14db5SEric W. Biederman 51577b14db5SEric W. Biederman ret = 0; 51677b14db5SEric W. Biederman /* Avoid a switch here: arm builds fail with missing __cmpdi2 */ 51777b14db5SEric W. Biederman if (filp->f_pos == 0) { 51877b14db5SEric W. Biederman if (filldir(dirent, ".", 1, filp->f_pos, 51977b14db5SEric W. Biederman inode->i_ino, DT_DIR) < 0) 52077b14db5SEric W. Biederman goto out; 52177b14db5SEric W. Biederman filp->f_pos++; 52277b14db5SEric W. Biederman } 52377b14db5SEric W. Biederman if (filp->f_pos == 1) { 52477b14db5SEric W. Biederman if (filldir(dirent, "..", 2, filp->f_pos, 52577b14db5SEric W. Biederman parent_ino(dentry), DT_DIR) < 0) 52677b14db5SEric W. Biederman goto out; 52777b14db5SEric W. Biederman filp->f_pos++; 52877b14db5SEric W. Biederman } 52977b14db5SEric W. Biederman pos = 2; 53077b14db5SEric W. Biederman 5319043476fSAl Viro ret = scan(head, table, &pos, filp, dirent, filldir); 5329043476fSAl Viro if (ret) 53377b14db5SEric W. Biederman goto out; 5349043476fSAl Viro 5359043476fSAl Viro for (h = sysctl_head_next(NULL); h; h = sysctl_head_next(h)) { 5369043476fSAl Viro if (h->attached_to != table) 5379043476fSAl Viro continue; 5389043476fSAl Viro ret = scan(h, h->attached_by, &pos, filp, dirent, filldir); 5399043476fSAl Viro if (ret) { 5409043476fSAl Viro sysctl_head_finish(h); 5419043476fSAl Viro break; 54277b14db5SEric W. Biederman } 54377b14db5SEric W. Biederman } 54477b14db5SEric W. Biederman ret = 1; 54577b14db5SEric W. Biederman out: 54677b14db5SEric W. Biederman sysctl_head_finish(head); 54777b14db5SEric W. Biederman return ret; 54877b14db5SEric W. Biederman } 54977b14db5SEric W. Biederman 55010556cb2SAl Viro static int proc_sys_permission(struct inode *inode, int mask) 55177b14db5SEric W. Biederman { 55277b14db5SEric W. Biederman /* 55377b14db5SEric W. Biederman * sysctl entries that are not writeable, 55477b14db5SEric W. Biederman * are _NOT_ writeable, capabilities or not. 55577b14db5SEric W. Biederman */ 556f696a365SMiklos Szeredi struct ctl_table_header *head; 557f696a365SMiklos Szeredi struct ctl_table *table; 55877b14db5SEric W. Biederman int error; 55977b14db5SEric W. Biederman 560f696a365SMiklos Szeredi /* Executable files are not allowed under /proc/sys/ */ 561f696a365SMiklos Szeredi if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) 562f696a365SMiklos Szeredi return -EACCES; 563f696a365SMiklos Szeredi 564f696a365SMiklos Szeredi head = grab_header(inode); 5659043476fSAl Viro if (IS_ERR(head)) 5669043476fSAl Viro return PTR_ERR(head); 56777b14db5SEric W. Biederman 568f696a365SMiklos Szeredi table = PROC_I(inode)->sysctl_entry; 5699043476fSAl Viro if (!table) /* global root - r-xr-xr-x */ 5709043476fSAl Viro error = mask & MAY_WRITE ? -EACCES : 0; 5719043476fSAl Viro else /* Use the permissions on the sysctl table entry */ 5721fc0f78cSAl Viro error = sysctl_perm(head->root, table, mask & ~MAY_NOT_BLOCK); 5739043476fSAl Viro 57477b14db5SEric W. Biederman sysctl_head_finish(head); 57577b14db5SEric W. Biederman return error; 57677b14db5SEric W. Biederman } 57777b14db5SEric W. Biederman 57877b14db5SEric W. Biederman static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr) 57977b14db5SEric W. Biederman { 58077b14db5SEric W. Biederman struct inode *inode = dentry->d_inode; 58177b14db5SEric W. Biederman int error; 58277b14db5SEric W. Biederman 58377b14db5SEric W. Biederman if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) 58477b14db5SEric W. Biederman return -EPERM; 58577b14db5SEric W. Biederman 58677b14db5SEric W. Biederman error = inode_change_ok(inode, attr); 5871025774cSChristoph Hellwig if (error) 58877b14db5SEric W. Biederman return error; 5891025774cSChristoph Hellwig 5901025774cSChristoph Hellwig if ((attr->ia_valid & ATTR_SIZE) && 5911025774cSChristoph Hellwig attr->ia_size != i_size_read(inode)) { 5921025774cSChristoph Hellwig error = vmtruncate(inode, attr->ia_size); 5931025774cSChristoph Hellwig if (error) 5941025774cSChristoph Hellwig return error; 5951025774cSChristoph Hellwig } 5961025774cSChristoph Hellwig 5971025774cSChristoph Hellwig setattr_copy(inode, attr); 5981025774cSChristoph Hellwig mark_inode_dirty(inode); 5991025774cSChristoph Hellwig return 0; 60077b14db5SEric W. Biederman } 60177b14db5SEric W. Biederman 6029043476fSAl Viro static int proc_sys_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 6039043476fSAl Viro { 6049043476fSAl Viro struct inode *inode = dentry->d_inode; 6059043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 6069043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 6079043476fSAl Viro 6089043476fSAl Viro if (IS_ERR(head)) 6099043476fSAl Viro return PTR_ERR(head); 6109043476fSAl Viro 6119043476fSAl Viro generic_fillattr(inode, stat); 6129043476fSAl Viro if (table) 6139043476fSAl Viro stat->mode = (stat->mode & S_IFMT) | table->mode; 6149043476fSAl Viro 6159043476fSAl Viro sysctl_head_finish(head); 6169043476fSAl Viro return 0; 6179043476fSAl Viro } 6189043476fSAl Viro 61977b14db5SEric W. Biederman static const struct file_operations proc_sys_file_operations = { 620f1ecf068SLucas De Marchi .open = proc_sys_open, 621f1ecf068SLucas De Marchi .poll = proc_sys_poll, 62277b14db5SEric W. Biederman .read = proc_sys_read, 62377b14db5SEric W. Biederman .write = proc_sys_write, 6246038f373SArnd Bergmann .llseek = default_llseek, 6259043476fSAl Viro }; 6269043476fSAl Viro 6279043476fSAl Viro static const struct file_operations proc_sys_dir_file_operations = { 628887df078SPavel Emelyanov .read = generic_read_dir, 62977b14db5SEric W. Biederman .readdir = proc_sys_readdir, 6303222a3e5SChristoph Hellwig .llseek = generic_file_llseek, 63177b14db5SEric W. Biederman }; 63277b14db5SEric W. Biederman 63303a44825SJan Engelhardt static const struct inode_operations proc_sys_inode_operations = { 6349043476fSAl Viro .permission = proc_sys_permission, 6359043476fSAl Viro .setattr = proc_sys_setattr, 6369043476fSAl Viro .getattr = proc_sys_getattr, 6379043476fSAl Viro }; 6389043476fSAl Viro 6399043476fSAl Viro static const struct inode_operations proc_sys_dir_operations = { 64077b14db5SEric W. Biederman .lookup = proc_sys_lookup, 64177b14db5SEric W. Biederman .permission = proc_sys_permission, 64277b14db5SEric W. Biederman .setattr = proc_sys_setattr, 6439043476fSAl Viro .getattr = proc_sys_getattr, 64477b14db5SEric W. Biederman }; 64577b14db5SEric W. Biederman 64677b14db5SEric W. Biederman static int proc_sys_revalidate(struct dentry *dentry, struct nameidata *nd) 64777b14db5SEric W. Biederman { 64834286d66SNick Piggin if (nd->flags & LOOKUP_RCU) 64934286d66SNick Piggin return -ECHILD; 6509043476fSAl Viro return !PROC_I(dentry->d_inode)->sysctl->unregistering; 6519043476fSAl Viro } 6529043476fSAl Viro 653fe15ce44SNick Piggin static int proc_sys_delete(const struct dentry *dentry) 6549043476fSAl Viro { 6559043476fSAl Viro return !!PROC_I(dentry->d_inode)->sysctl->unregistering; 6569043476fSAl Viro } 6579043476fSAl Viro 6581f87f0b5SEric W. Biederman static int sysctl_is_seen(struct ctl_table_header *p) 6591f87f0b5SEric W. Biederman { 6601f87f0b5SEric W. Biederman struct ctl_table_set *set = p->set; 6611f87f0b5SEric W. Biederman int res; 6621f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 6631f87f0b5SEric W. Biederman if (p->unregistering) 6641f87f0b5SEric W. Biederman res = 0; 6651f87f0b5SEric W. Biederman else if (!set->is_seen) 6661f87f0b5SEric W. Biederman res = 1; 6671f87f0b5SEric W. Biederman else 6681f87f0b5SEric W. Biederman res = set->is_seen(set); 6691f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 6701f87f0b5SEric W. Biederman return res; 6711f87f0b5SEric W. Biederman } 6721f87f0b5SEric W. Biederman 673621e155aSNick Piggin static int proc_sys_compare(const struct dentry *parent, 674621e155aSNick Piggin const struct inode *pinode, 675621e155aSNick Piggin const struct dentry *dentry, const struct inode *inode, 676621e155aSNick Piggin unsigned int len, const char *str, const struct qstr *name) 6779043476fSAl Viro { 678dfef6dcdSAl Viro struct ctl_table_header *head; 67931e6b01fSNick Piggin /* Although proc doesn't have negative dentries, rcu-walk means 68031e6b01fSNick Piggin * that inode here can be NULL */ 681dfef6dcdSAl Viro /* AV: can it, indeed? */ 68231e6b01fSNick Piggin if (!inode) 683dfef6dcdSAl Viro return 1; 684621e155aSNick Piggin if (name->len != len) 6859043476fSAl Viro return 1; 686621e155aSNick Piggin if (memcmp(name->name, str, len)) 6879043476fSAl Viro return 1; 688dfef6dcdSAl Viro head = rcu_dereference(PROC_I(inode)->sysctl); 689dfef6dcdSAl Viro return !head || !sysctl_is_seen(head); 69077b14db5SEric W. Biederman } 69177b14db5SEric W. Biederman 692d72f71ebSAl Viro static const struct dentry_operations proc_sys_dentry_operations = { 69377b14db5SEric W. Biederman .d_revalidate = proc_sys_revalidate, 6949043476fSAl Viro .d_delete = proc_sys_delete, 6959043476fSAl Viro .d_compare = proc_sys_compare, 69677b14db5SEric W. Biederman }; 69777b14db5SEric W. Biederman 6981f87f0b5SEric W. Biederman static struct ctl_table *is_branch_in(struct ctl_table *branch, 6991f87f0b5SEric W. Biederman struct ctl_table *table) 7001f87f0b5SEric W. Biederman { 7011f87f0b5SEric W. Biederman struct ctl_table *p; 7021f87f0b5SEric W. Biederman const char *s = branch->procname; 7031f87f0b5SEric W. Biederman 7041f87f0b5SEric W. Biederman /* branch should have named subdirectory as its first element */ 7051f87f0b5SEric W. Biederman if (!s || !branch->child) 7061f87f0b5SEric W. Biederman return NULL; 7071f87f0b5SEric W. Biederman 7081f87f0b5SEric W. Biederman /* ... and nothing else */ 7091f87f0b5SEric W. Biederman if (branch[1].procname) 7101f87f0b5SEric W. Biederman return NULL; 7111f87f0b5SEric W. Biederman 7121f87f0b5SEric W. Biederman /* table should contain subdirectory with the same name */ 7131f87f0b5SEric W. Biederman for (p = table; p->procname; p++) { 7141f87f0b5SEric W. Biederman if (!p->child) 7151f87f0b5SEric W. Biederman continue; 7161f87f0b5SEric W. Biederman if (p->procname && strcmp(p->procname, s) == 0) 7171f87f0b5SEric W. Biederman return p; 7181f87f0b5SEric W. Biederman } 7191f87f0b5SEric W. Biederman return NULL; 7201f87f0b5SEric W. Biederman } 7211f87f0b5SEric W. Biederman 7221f87f0b5SEric W. Biederman /* see if attaching q to p would be an improvement */ 7231f87f0b5SEric W. Biederman static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q) 7241f87f0b5SEric W. Biederman { 7251f87f0b5SEric W. Biederman struct ctl_table *to = p->ctl_table, *by = q->ctl_table; 7261f87f0b5SEric W. Biederman struct ctl_table *next; 7271f87f0b5SEric W. Biederman int is_better = 0; 7281f87f0b5SEric W. Biederman int not_in_parent = !p->attached_by; 7291f87f0b5SEric W. Biederman 7301f87f0b5SEric W. Biederman while ((next = is_branch_in(by, to)) != NULL) { 7311f87f0b5SEric W. Biederman if (by == q->attached_by) 7321f87f0b5SEric W. Biederman is_better = 1; 7331f87f0b5SEric W. Biederman if (to == p->attached_by) 7341f87f0b5SEric W. Biederman not_in_parent = 1; 7351f87f0b5SEric W. Biederman by = by->child; 7361f87f0b5SEric W. Biederman to = next->child; 7371f87f0b5SEric W. Biederman } 7381f87f0b5SEric W. Biederman 7391f87f0b5SEric W. Biederman if (is_better && not_in_parent) { 7401f87f0b5SEric W. Biederman q->attached_by = by; 7411f87f0b5SEric W. Biederman q->attached_to = to; 7421f87f0b5SEric W. Biederman q->parent = p; 7431f87f0b5SEric W. Biederman } 7441f87f0b5SEric W. Biederman } 7451f87f0b5SEric W. Biederman 7467c60c48fSEric W. Biederman static int sysctl_check_table_dups(const char *path, struct ctl_table *old, 7471f87f0b5SEric W. Biederman struct ctl_table *table) 7481f87f0b5SEric W. Biederman { 7497c60c48fSEric W. Biederman struct ctl_table *entry, *test; 7501f87f0b5SEric W. Biederman int error = 0; 7511f87f0b5SEric W. Biederman 7527c60c48fSEric W. Biederman for (entry = old; entry->procname; entry++) { 7537c60c48fSEric W. Biederman for (test = table; test->procname; test++) { 7547c60c48fSEric W. Biederman if (strcmp(entry->procname, test->procname) == 0) { 7557c60c48fSEric W. Biederman printk(KERN_ERR "sysctl duplicate entry: %s/%s\n", 7567c60c48fSEric W. Biederman path, test->procname); 7577c60c48fSEric W. Biederman error = -EEXIST; 7581f87f0b5SEric W. Biederman } 7597c60c48fSEric W. Biederman } 7607c60c48fSEric W. Biederman } 7617c60c48fSEric W. Biederman return error; 7627c60c48fSEric W. Biederman } 7637c60c48fSEric W. Biederman 7647c60c48fSEric W. Biederman static int sysctl_check_dups(struct nsproxy *namespaces, 7657c60c48fSEric W. Biederman struct ctl_table_header *header, 7667c60c48fSEric W. Biederman const char *path, struct ctl_table *table) 7677c60c48fSEric W. Biederman { 7687c60c48fSEric W. Biederman struct ctl_table_root *root; 7697c60c48fSEric W. Biederman struct ctl_table_set *set; 7707c60c48fSEric W. Biederman struct ctl_table_header *dir_head, *head; 7717c60c48fSEric W. Biederman struct ctl_table *dir_table; 7727c60c48fSEric W. Biederman int error = 0; 7737c60c48fSEric W. Biederman 7747c60c48fSEric W. Biederman /* No dups if we are the only member of our directory */ 7757c60c48fSEric W. Biederman if (header->attached_by != table) 7767c60c48fSEric W. Biederman return 0; 7777c60c48fSEric W. Biederman 7787c60c48fSEric W. Biederman dir_head = header->parent; 7797c60c48fSEric W. Biederman dir_table = header->attached_to; 7807c60c48fSEric W. Biederman 7817c60c48fSEric W. Biederman error = sysctl_check_table_dups(path, dir_table, table); 7827c60c48fSEric W. Biederman 7837c60c48fSEric W. Biederman root = &sysctl_table_root; 7847c60c48fSEric W. Biederman do { 7857c60c48fSEric W. Biederman set = lookup_header_set(root, namespaces); 7867c60c48fSEric W. Biederman 7877c60c48fSEric W. Biederman list_for_each_entry(head, &set->list, ctl_entry) { 7887c60c48fSEric W. Biederman if (head->unregistering) 7897c60c48fSEric W. Biederman continue; 7907c60c48fSEric W. Biederman if (head->attached_to != dir_table) 7917c60c48fSEric W. Biederman continue; 7927c60c48fSEric W. Biederman error = sysctl_check_table_dups(path, head->attached_by, 7937c60c48fSEric W. Biederman table); 7947c60c48fSEric W. Biederman } 7957c60c48fSEric W. Biederman root = list_entry(root->root_list.next, 7967c60c48fSEric W. Biederman struct ctl_table_root, root_list); 7977c60c48fSEric W. Biederman } while (root != &sysctl_table_root); 7987c60c48fSEric W. Biederman return error; 7997c60c48fSEric W. Biederman } 8007c60c48fSEric W. Biederman 8017c60c48fSEric W. Biederman static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...) 8027c60c48fSEric W. Biederman { 8037c60c48fSEric W. Biederman struct va_format vaf; 8047c60c48fSEric W. Biederman va_list args; 8057c60c48fSEric W. Biederman 8067c60c48fSEric W. Biederman va_start(args, fmt); 8077c60c48fSEric W. Biederman vaf.fmt = fmt; 8087c60c48fSEric W. Biederman vaf.va = &args; 8097c60c48fSEric W. Biederman 8107c60c48fSEric W. Biederman printk(KERN_ERR "sysctl table check failed: %s/%s %pV\n", 8117c60c48fSEric W. Biederman path, table->procname, &vaf); 8127c60c48fSEric W. Biederman 8137c60c48fSEric W. Biederman va_end(args); 8147c60c48fSEric W. Biederman return -EINVAL; 8157c60c48fSEric W. Biederman } 8167c60c48fSEric W. Biederman 8177c60c48fSEric W. Biederman static int sysctl_check_table(const char *path, struct ctl_table *table) 8187c60c48fSEric W. Biederman { 8197c60c48fSEric W. Biederman int err = 0; 8207c60c48fSEric W. Biederman for (; table->procname; table++) { 8217c60c48fSEric W. Biederman if (table->child) 8227c60c48fSEric W. Biederman err = sysctl_err(path, table, "Not a file"); 8237c60c48fSEric W. Biederman 8241f87f0b5SEric W. Biederman if ((table->proc_handler == proc_dostring) || 8251f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec) || 8261f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_minmax) || 8271f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_jiffies) || 8281f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_userhz_jiffies) || 8291f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_ms_jiffies) || 8301f87f0b5SEric W. Biederman (table->proc_handler == proc_doulongvec_minmax) || 8311f87f0b5SEric W. Biederman (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) { 8321f87f0b5SEric W. Biederman if (!table->data) 8337c60c48fSEric W. Biederman err = sysctl_err(path, table, "No data"); 8341f87f0b5SEric W. Biederman if (!table->maxlen) 8357c60c48fSEric W. Biederman err = sysctl_err(path, table, "No maxlen"); 8361f87f0b5SEric W. Biederman } 8371f87f0b5SEric W. Biederman if (!table->proc_handler) 8387c60c48fSEric W. Biederman err = sysctl_err(path, table, "No proc_handler"); 8397c60c48fSEric W. Biederman 8407c60c48fSEric W. Biederman if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode) 8417c60c48fSEric W. Biederman err = sysctl_err(path, table, "bogus .mode 0%o", 8427c60c48fSEric W. Biederman table->mode); 8431f87f0b5SEric W. Biederman } 8447c60c48fSEric W. Biederman return err; 8451f87f0b5SEric W. Biederman } 8461f87f0b5SEric W. Biederman 8471f87f0b5SEric W. Biederman /** 848f728019bSEric W. Biederman * __register_sysctl_table - register a leaf sysctl table 8491f87f0b5SEric W. Biederman * @root: List of sysctl headers to register on 8501f87f0b5SEric W. Biederman * @namespaces: Data to compute which lists of sysctl entries are visible 8511f87f0b5SEric W. Biederman * @path: The path to the directory the sysctl table is in. 8521f87f0b5SEric W. Biederman * @table: the top-level table structure 8531f87f0b5SEric W. Biederman * 8541f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 8551f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 8561f87f0b5SEric W. Biederman * 8571f87f0b5SEric W. Biederman * The members of the &struct ctl_table structure are used as follows: 8581f87f0b5SEric W. Biederman * 8591f87f0b5SEric W. Biederman * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not 8601f87f0b5SEric W. Biederman * enter a sysctl file 8611f87f0b5SEric W. Biederman * 8621f87f0b5SEric W. Biederman * data - a pointer to data for use by proc_handler 8631f87f0b5SEric W. Biederman * 8641f87f0b5SEric W. Biederman * maxlen - the maximum size in bytes of the data 8651f87f0b5SEric W. Biederman * 866f728019bSEric W. Biederman * mode - the file permissions for the /proc/sys file 8671f87f0b5SEric W. Biederman * 868f728019bSEric W. Biederman * child - must be %NULL. 8691f87f0b5SEric W. Biederman * 8701f87f0b5SEric W. Biederman * proc_handler - the text handler routine (described below) 8711f87f0b5SEric W. Biederman * 8721f87f0b5SEric W. Biederman * extra1, extra2 - extra pointers usable by the proc handler routines 8731f87f0b5SEric W. Biederman * 8741f87f0b5SEric W. Biederman * Leaf nodes in the sysctl tree will be represented by a single file 8751f87f0b5SEric W. Biederman * under /proc; non-leaf nodes will be represented by directories. 8761f87f0b5SEric W. Biederman * 877f728019bSEric W. Biederman * There must be a proc_handler routine for any terminal nodes. 878f728019bSEric W. Biederman * Several default handlers are available to cover common cases - 8791f87f0b5SEric W. Biederman * 8801f87f0b5SEric W. Biederman * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), 8811f87f0b5SEric W. Biederman * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 8821f87f0b5SEric W. Biederman * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() 8831f87f0b5SEric W. Biederman * 8841f87f0b5SEric W. Biederman * It is the handler's job to read the input buffer from user memory 8851f87f0b5SEric W. Biederman * and process it. The handler should return 0 on success. 8861f87f0b5SEric W. Biederman * 8871f87f0b5SEric W. Biederman * This routine returns %NULL on a failure to register, and a pointer 8881f87f0b5SEric W. Biederman * to the table header on success. 8891f87f0b5SEric W. Biederman */ 8906e9d5164SEric W. Biederman struct ctl_table_header *__register_sysctl_table( 8911f87f0b5SEric W. Biederman struct ctl_table_root *root, 8921f87f0b5SEric W. Biederman struct nsproxy *namespaces, 8936e9d5164SEric W. Biederman const char *path, struct ctl_table *table) 8941f87f0b5SEric W. Biederman { 8951f87f0b5SEric W. Biederman struct ctl_table_header *header; 8961f87f0b5SEric W. Biederman struct ctl_table *new, **prevp; 8976e9d5164SEric W. Biederman const char *name, *nextname; 8986e9d5164SEric W. Biederman unsigned int npath = 0; 8991f87f0b5SEric W. Biederman struct ctl_table_set *set; 900f05e53a7SEric W. Biederman size_t path_bytes = 0; 901f05e53a7SEric W. Biederman char *new_name; 9021f87f0b5SEric W. Biederman 9031f87f0b5SEric W. Biederman /* Count the path components */ 9046e9d5164SEric W. Biederman for (name = path; name; name = nextname) { 9056e9d5164SEric W. Biederman int namelen; 9066e9d5164SEric W. Biederman nextname = strchr(name, '/'); 9076e9d5164SEric W. Biederman if (nextname) { 9086e9d5164SEric W. Biederman namelen = nextname - name; 9096e9d5164SEric W. Biederman nextname++; 9106e9d5164SEric W. Biederman } else { 9116e9d5164SEric W. Biederman namelen = strlen(name); 9126e9d5164SEric W. Biederman } 9136e9d5164SEric W. Biederman if (namelen == 0) 9146e9d5164SEric W. Biederman continue; 9156e9d5164SEric W. Biederman path_bytes += namelen + 1; 9166e9d5164SEric W. Biederman npath++; 9176e9d5164SEric W. Biederman } 9181f87f0b5SEric W. Biederman 9191f87f0b5SEric W. Biederman /* 9201f87f0b5SEric W. Biederman * For each path component, allocate a 2-element ctl_table array. 9211f87f0b5SEric W. Biederman * The first array element will be filled with the sysctl entry 9221f87f0b5SEric W. Biederman * for this, the second will be the sentinel (procname == 0). 9231f87f0b5SEric W. Biederman * 9241f87f0b5SEric W. Biederman * We allocate everything in one go so that we don't have to 9251f87f0b5SEric W. Biederman * worry about freeing additional memory in unregister_sysctl_table. 9261f87f0b5SEric W. Biederman */ 927f05e53a7SEric W. Biederman header = kzalloc(sizeof(struct ctl_table_header) + path_bytes + 9281f87f0b5SEric W. Biederman (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL); 9291f87f0b5SEric W. Biederman if (!header) 9301f87f0b5SEric W. Biederman return NULL; 9311f87f0b5SEric W. Biederman 9321f87f0b5SEric W. Biederman new = (struct ctl_table *) (header + 1); 933f05e53a7SEric W. Biederman new_name = (char *)(new + (2 * npath)); 9341f87f0b5SEric W. Biederman 9351f87f0b5SEric W. Biederman /* Now connect the dots */ 9361f87f0b5SEric W. Biederman prevp = &header->ctl_table; 9376e9d5164SEric W. Biederman for (name = path; name; name = nextname) { 9386e9d5164SEric W. Biederman int namelen; 9396e9d5164SEric W. Biederman nextname = strchr(name, '/'); 9406e9d5164SEric W. Biederman if (nextname) { 9416e9d5164SEric W. Biederman namelen = nextname - name; 9426e9d5164SEric W. Biederman nextname++; 9436e9d5164SEric W. Biederman } else { 9446e9d5164SEric W. Biederman namelen = strlen(name); 9456e9d5164SEric W. Biederman } 9466e9d5164SEric W. Biederman if (namelen == 0) 9476e9d5164SEric W. Biederman continue; 9486e9d5164SEric W. Biederman memcpy(new_name, name, namelen); 9496e9d5164SEric W. Biederman new_name[namelen] = '\0'; 9506e9d5164SEric W. Biederman 951f05e53a7SEric W. Biederman new->procname = new_name; 9521f87f0b5SEric W. Biederman new->mode = 0555; 9531f87f0b5SEric W. Biederman 9541f87f0b5SEric W. Biederman *prevp = new; 9551f87f0b5SEric W. Biederman prevp = &new->child; 9561f87f0b5SEric W. Biederman 9571f87f0b5SEric W. Biederman new += 2; 9586e9d5164SEric W. Biederman new_name += namelen + 1; 9591f87f0b5SEric W. Biederman } 9601f87f0b5SEric W. Biederman *prevp = table; 9611f87f0b5SEric W. Biederman 962e0d04529SEric W. Biederman init_header(header, root, NULL, table); 9637c60c48fSEric W. Biederman if (sysctl_check_table(path, table)) 9647c60c48fSEric W. Biederman goto fail; 9658d6ecfccSEric W. Biederman 9661f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 9671f87f0b5SEric W. Biederman header->set = lookup_header_set(root, namespaces); 9681f87f0b5SEric W. Biederman header->attached_by = header->ctl_table; 9691f87f0b5SEric W. Biederman header->attached_to = root_table; 9701f87f0b5SEric W. Biederman header->parent = &root_table_header; 971bd295b56SEric W. Biederman set = header->set; 972bd295b56SEric W. Biederman root = header->root; 973bd295b56SEric W. Biederman for (;;) { 9741f87f0b5SEric W. Biederman struct ctl_table_header *p; 9751f87f0b5SEric W. Biederman list_for_each_entry(p, &set->list, ctl_entry) { 9761f87f0b5SEric W. Biederman if (p->unregistering) 9771f87f0b5SEric W. Biederman continue; 9781f87f0b5SEric W. Biederman try_attach(p, header); 9791f87f0b5SEric W. Biederman } 980bd295b56SEric W. Biederman if (root == &sysctl_table_root) 981bd295b56SEric W. Biederman break; 982bd295b56SEric W. Biederman root = list_entry(root->root_list.prev, 983bd295b56SEric W. Biederman struct ctl_table_root, root_list); 984bd295b56SEric W. Biederman set = lookup_header_set(root, namespaces); 9851f87f0b5SEric W. Biederman } 9867c60c48fSEric W. Biederman if (sysctl_check_dups(namespaces, header, path, table)) 9877c60c48fSEric W. Biederman goto fail_locked; 9888425d6aaSEric W. Biederman insert_header(header); 9891f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 9901f87f0b5SEric W. Biederman 9911f87f0b5SEric W. Biederman return header; 9927c60c48fSEric W. Biederman fail_locked: 9937c60c48fSEric W. Biederman spin_unlock(&sysctl_lock); 9947c60c48fSEric W. Biederman fail: 9957c60c48fSEric W. Biederman kfree(header); 9967c60c48fSEric W. Biederman dump_stack(); 9977c60c48fSEric W. Biederman return NULL; 9981f87f0b5SEric W. Biederman } 9991f87f0b5SEric W. Biederman 10006e9d5164SEric W. Biederman static char *append_path(const char *path, char *pos, const char *name) 10016e9d5164SEric W. Biederman { 10026e9d5164SEric W. Biederman int namelen; 10036e9d5164SEric W. Biederman namelen = strlen(name); 10046e9d5164SEric W. Biederman if (((pos - path) + namelen + 2) >= PATH_MAX) 10056e9d5164SEric W. Biederman return NULL; 10066e9d5164SEric W. Biederman memcpy(pos, name, namelen); 10076e9d5164SEric W. Biederman pos[namelen] = '/'; 10086e9d5164SEric W. Biederman pos[namelen + 1] = '\0'; 10096e9d5164SEric W. Biederman pos += namelen + 1; 10106e9d5164SEric W. Biederman return pos; 10116e9d5164SEric W. Biederman } 10126e9d5164SEric W. Biederman 1013f728019bSEric W. Biederman static int count_subheaders(struct ctl_table *table) 1014f728019bSEric W. Biederman { 1015f728019bSEric W. Biederman int has_files = 0; 1016f728019bSEric W. Biederman int nr_subheaders = 0; 1017f728019bSEric W. Biederman struct ctl_table *entry; 1018f728019bSEric W. Biederman 1019f728019bSEric W. Biederman /* special case: no directory and empty directory */ 1020f728019bSEric W. Biederman if (!table || !table->procname) 1021f728019bSEric W. Biederman return 1; 1022f728019bSEric W. Biederman 1023f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1024f728019bSEric W. Biederman if (entry->child) 1025f728019bSEric W. Biederman nr_subheaders += count_subheaders(entry->child); 1026f728019bSEric W. Biederman else 1027f728019bSEric W. Biederman has_files = 1; 1028f728019bSEric W. Biederman } 1029f728019bSEric W. Biederman return nr_subheaders + has_files; 1030f728019bSEric W. Biederman } 1031f728019bSEric W. Biederman 1032f728019bSEric W. Biederman static int register_leaf_sysctl_tables(const char *path, char *pos, 1033f728019bSEric W. Biederman struct ctl_table_header ***subheader, 1034f728019bSEric W. Biederman struct ctl_table_root *root, struct nsproxy *namespaces, 1035f728019bSEric W. Biederman struct ctl_table *table) 1036f728019bSEric W. Biederman { 1037f728019bSEric W. Biederman struct ctl_table *ctl_table_arg = NULL; 1038f728019bSEric W. Biederman struct ctl_table *entry, *files; 1039f728019bSEric W. Biederman int nr_files = 0; 1040f728019bSEric W. Biederman int nr_dirs = 0; 1041f728019bSEric W. Biederman int err = -ENOMEM; 1042f728019bSEric W. Biederman 1043f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1044f728019bSEric W. Biederman if (entry->child) 1045f728019bSEric W. Biederman nr_dirs++; 1046f728019bSEric W. Biederman else 1047f728019bSEric W. Biederman nr_files++; 1048f728019bSEric W. Biederman } 1049f728019bSEric W. Biederman 1050f728019bSEric W. Biederman files = table; 1051f728019bSEric W. Biederman /* If there are mixed files and directories we need a new table */ 1052f728019bSEric W. Biederman if (nr_dirs && nr_files) { 1053f728019bSEric W. Biederman struct ctl_table *new; 1054f728019bSEric W. Biederman files = kzalloc(sizeof(struct ctl_table) * (nr_files + 1), 1055f728019bSEric W. Biederman GFP_KERNEL); 1056f728019bSEric W. Biederman if (!files) 1057f728019bSEric W. Biederman goto out; 1058f728019bSEric W. Biederman 1059f728019bSEric W. Biederman ctl_table_arg = files; 1060f728019bSEric W. Biederman for (new = files, entry = table; entry->procname; entry++) { 1061f728019bSEric W. Biederman if (entry->child) 1062f728019bSEric W. Biederman continue; 1063f728019bSEric W. Biederman *new = *entry; 1064f728019bSEric W. Biederman new++; 1065f728019bSEric W. Biederman } 1066f728019bSEric W. Biederman } 1067f728019bSEric W. Biederman 1068f728019bSEric W. Biederman /* Register everything except a directory full of subdirectories */ 1069f728019bSEric W. Biederman if (nr_files || !nr_dirs) { 1070f728019bSEric W. Biederman struct ctl_table_header *header; 1071f728019bSEric W. Biederman header = __register_sysctl_table(root, namespaces, path, files); 1072f728019bSEric W. Biederman if (!header) { 1073f728019bSEric W. Biederman kfree(ctl_table_arg); 1074f728019bSEric W. Biederman goto out; 1075f728019bSEric W. Biederman } 1076f728019bSEric W. Biederman 1077f728019bSEric W. Biederman /* Remember if we need to free the file table */ 1078f728019bSEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1079f728019bSEric W. Biederman **subheader = header; 1080f728019bSEric W. Biederman (*subheader)++; 1081f728019bSEric W. Biederman } 1082f728019bSEric W. Biederman 1083f728019bSEric W. Biederman /* Recurse into the subdirectories. */ 1084f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1085f728019bSEric W. Biederman char *child_pos; 1086f728019bSEric W. Biederman 1087f728019bSEric W. Biederman if (!entry->child) 1088f728019bSEric W. Biederman continue; 1089f728019bSEric W. Biederman 1090f728019bSEric W. Biederman err = -ENAMETOOLONG; 1091f728019bSEric W. Biederman child_pos = append_path(path, pos, entry->procname); 1092f728019bSEric W. Biederman if (!child_pos) 1093f728019bSEric W. Biederman goto out; 1094f728019bSEric W. Biederman 1095f728019bSEric W. Biederman err = register_leaf_sysctl_tables(path, child_pos, subheader, 1096f728019bSEric W. Biederman root, namespaces, entry->child); 1097f728019bSEric W. Biederman pos[0] = '\0'; 1098f728019bSEric W. Biederman if (err) 1099f728019bSEric W. Biederman goto out; 1100f728019bSEric W. Biederman } 1101f728019bSEric W. Biederman err = 0; 1102f728019bSEric W. Biederman out: 1103f728019bSEric W. Biederman /* On failure our caller will unregister all registered subheaders */ 1104f728019bSEric W. Biederman return err; 1105f728019bSEric W. Biederman } 1106f728019bSEric W. Biederman 11076e9d5164SEric W. Biederman /** 11086e9d5164SEric W. Biederman * __register_sysctl_paths - register a sysctl table hierarchy 11096e9d5164SEric W. Biederman * @root: List of sysctl headers to register on 11106e9d5164SEric W. Biederman * @namespaces: Data to compute which lists of sysctl entries are visible 11116e9d5164SEric W. Biederman * @path: The path to the directory the sysctl table is in. 11126e9d5164SEric W. Biederman * @table: the top-level table structure 11136e9d5164SEric W. Biederman * 11146e9d5164SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 11156e9d5164SEric W. Biederman * array. A completely 0 filled entry terminates the table. 11166e9d5164SEric W. Biederman * 11176e9d5164SEric W. Biederman * See __register_sysctl_table for more details. 11186e9d5164SEric W. Biederman */ 11196e9d5164SEric W. Biederman struct ctl_table_header *__register_sysctl_paths( 11206e9d5164SEric W. Biederman struct ctl_table_root *root, 11216e9d5164SEric W. Biederman struct nsproxy *namespaces, 11226e9d5164SEric W. Biederman const struct ctl_path *path, struct ctl_table *table) 11236e9d5164SEric W. Biederman { 1124ec6a5266SEric W. Biederman struct ctl_table *ctl_table_arg = table; 1125f728019bSEric W. Biederman int nr_subheaders = count_subheaders(table); 1126f728019bSEric W. Biederman struct ctl_table_header *header = NULL, **subheaders, **subheader; 11276e9d5164SEric W. Biederman const struct ctl_path *component; 11286e9d5164SEric W. Biederman char *new_path, *pos; 11296e9d5164SEric W. Biederman 11306e9d5164SEric W. Biederman pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); 11316e9d5164SEric W. Biederman if (!new_path) 11326e9d5164SEric W. Biederman return NULL; 11336e9d5164SEric W. Biederman 11346e9d5164SEric W. Biederman pos[0] = '\0'; 11356e9d5164SEric W. Biederman for (component = path; component->procname; component++) { 11366e9d5164SEric W. Biederman pos = append_path(new_path, pos, component->procname); 11376e9d5164SEric W. Biederman if (!pos) 11386e9d5164SEric W. Biederman goto out; 11396e9d5164SEric W. Biederman } 1140ec6a5266SEric W. Biederman while (table->procname && table->child && !table[1].procname) { 1141ec6a5266SEric W. Biederman pos = append_path(new_path, pos, table->procname); 1142ec6a5266SEric W. Biederman if (!pos) 1143ec6a5266SEric W. Biederman goto out; 1144ec6a5266SEric W. Biederman table = table->child; 1145ec6a5266SEric W. Biederman } 1146f728019bSEric W. Biederman if (nr_subheaders == 1) { 11476e9d5164SEric W. Biederman header = __register_sysctl_table(root, namespaces, new_path, table); 1148ec6a5266SEric W. Biederman if (header) 1149ec6a5266SEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1150f728019bSEric W. Biederman } else { 1151f728019bSEric W. Biederman header = kzalloc(sizeof(*header) + 1152f728019bSEric W. Biederman sizeof(*subheaders)*nr_subheaders, GFP_KERNEL); 1153f728019bSEric W. Biederman if (!header) 1154f728019bSEric W. Biederman goto out; 1155f728019bSEric W. Biederman 1156f728019bSEric W. Biederman subheaders = (struct ctl_table_header **) (header + 1); 1157f728019bSEric W. Biederman subheader = subheaders; 1158f728019bSEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1159f728019bSEric W. Biederman 1160f728019bSEric W. Biederman if (register_leaf_sysctl_tables(new_path, pos, &subheader, 1161f728019bSEric W. Biederman root, namespaces, table)) 1162f728019bSEric W. Biederman goto err_register_leaves; 1163f728019bSEric W. Biederman } 1164f728019bSEric W. Biederman 11656e9d5164SEric W. Biederman out: 11666e9d5164SEric W. Biederman kfree(new_path); 11676e9d5164SEric W. Biederman return header; 1168f728019bSEric W. Biederman 1169f728019bSEric W. Biederman err_register_leaves: 1170f728019bSEric W. Biederman while (subheader > subheaders) { 1171f728019bSEric W. Biederman struct ctl_table_header *subh = *(--subheader); 1172f728019bSEric W. Biederman struct ctl_table *table = subh->ctl_table_arg; 1173f728019bSEric W. Biederman unregister_sysctl_table(subh); 1174f728019bSEric W. Biederman kfree(table); 1175f728019bSEric W. Biederman } 1176f728019bSEric W. Biederman kfree(header); 1177f728019bSEric W. Biederman header = NULL; 1178f728019bSEric W. Biederman goto out; 11796e9d5164SEric W. Biederman } 11806e9d5164SEric W. Biederman 11811f87f0b5SEric W. Biederman /** 11821f87f0b5SEric W. Biederman * register_sysctl_table_path - register a sysctl table hierarchy 11831f87f0b5SEric W. Biederman * @path: The path to the directory the sysctl table is in. 11841f87f0b5SEric W. Biederman * @table: the top-level table structure 11851f87f0b5SEric W. Biederman * 11861f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 11871f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 11881f87f0b5SEric W. Biederman * 11891f87f0b5SEric W. Biederman * See __register_sysctl_paths for more details. 11901f87f0b5SEric W. Biederman */ 11911f87f0b5SEric W. Biederman struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, 11921f87f0b5SEric W. Biederman struct ctl_table *table) 11931f87f0b5SEric W. Biederman { 11941f87f0b5SEric W. Biederman return __register_sysctl_paths(&sysctl_table_root, current->nsproxy, 11951f87f0b5SEric W. Biederman path, table); 11961f87f0b5SEric W. Biederman } 11971f87f0b5SEric W. Biederman EXPORT_SYMBOL(register_sysctl_paths); 11981f87f0b5SEric W. Biederman 11991f87f0b5SEric W. Biederman /** 12001f87f0b5SEric W. Biederman * register_sysctl_table - register a sysctl table hierarchy 12011f87f0b5SEric W. Biederman * @table: the top-level table structure 12021f87f0b5SEric W. Biederman * 12031f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 12041f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 12051f87f0b5SEric W. Biederman * 12061f87f0b5SEric W. Biederman * See register_sysctl_paths for more details. 12071f87f0b5SEric W. Biederman */ 12081f87f0b5SEric W. Biederman struct ctl_table_header *register_sysctl_table(struct ctl_table *table) 12091f87f0b5SEric W. Biederman { 12101f87f0b5SEric W. Biederman static const struct ctl_path null_path[] = { {} }; 12111f87f0b5SEric W. Biederman 12121f87f0b5SEric W. Biederman return register_sysctl_paths(null_path, table); 12131f87f0b5SEric W. Biederman } 12141f87f0b5SEric W. Biederman EXPORT_SYMBOL(register_sysctl_table); 12151f87f0b5SEric W. Biederman 1216938aaa4fSEric W. Biederman static void drop_sysctl_table(struct ctl_table_header *header) 1217938aaa4fSEric W. Biederman { 1218938aaa4fSEric W. Biederman if (--header->nreg) 1219938aaa4fSEric W. Biederman return; 1220938aaa4fSEric W. Biederman 1221938aaa4fSEric W. Biederman start_unregistering(header); 1222938aaa4fSEric W. Biederman if (!--header->parent->count) { 1223938aaa4fSEric W. Biederman WARN_ON(1); 1224938aaa4fSEric W. Biederman kfree_rcu(header->parent, rcu); 1225938aaa4fSEric W. Biederman } 1226938aaa4fSEric W. Biederman if (!--header->count) 1227938aaa4fSEric W. Biederman kfree_rcu(header, rcu); 1228938aaa4fSEric W. Biederman } 1229938aaa4fSEric W. Biederman 12301f87f0b5SEric W. Biederman /** 12311f87f0b5SEric W. Biederman * unregister_sysctl_table - unregister a sysctl table hierarchy 12321f87f0b5SEric W. Biederman * @header: the header returned from register_sysctl_table 12331f87f0b5SEric W. Biederman * 12341f87f0b5SEric W. Biederman * Unregisters the sysctl table and all children. proc entries may not 12351f87f0b5SEric W. Biederman * actually be removed until they are no longer used by anyone. 12361f87f0b5SEric W. Biederman */ 12371f87f0b5SEric W. Biederman void unregister_sysctl_table(struct ctl_table_header * header) 12381f87f0b5SEric W. Biederman { 1239f728019bSEric W. Biederman int nr_subheaders; 12401f87f0b5SEric W. Biederman might_sleep(); 12411f87f0b5SEric W. Biederman 12421f87f0b5SEric W. Biederman if (header == NULL) 12431f87f0b5SEric W. Biederman return; 12441f87f0b5SEric W. Biederman 1245f728019bSEric W. Biederman nr_subheaders = count_subheaders(header->ctl_table_arg); 1246f728019bSEric W. Biederman if (unlikely(nr_subheaders > 1)) { 1247f728019bSEric W. Biederman struct ctl_table_header **subheaders; 1248f728019bSEric W. Biederman int i; 1249f728019bSEric W. Biederman 1250f728019bSEric W. Biederman subheaders = (struct ctl_table_header **)(header + 1); 1251f728019bSEric W. Biederman for (i = nr_subheaders -1; i >= 0; i--) { 1252f728019bSEric W. Biederman struct ctl_table_header *subh = subheaders[i]; 1253f728019bSEric W. Biederman struct ctl_table *table = subh->ctl_table_arg; 1254f728019bSEric W. Biederman unregister_sysctl_table(subh); 1255f728019bSEric W. Biederman kfree(table); 1256f728019bSEric W. Biederman } 1257f728019bSEric W. Biederman kfree(header); 1258f728019bSEric W. Biederman return; 1259f728019bSEric W. Biederman } 1260f728019bSEric W. Biederman 12611f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1262938aaa4fSEric W. Biederman drop_sysctl_table(header); 12631f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 12641f87f0b5SEric W. Biederman } 12651f87f0b5SEric W. Biederman EXPORT_SYMBOL(unregister_sysctl_table); 12661f87f0b5SEric W. Biederman 12671f87f0b5SEric W. Biederman void setup_sysctl_set(struct ctl_table_set *p, 12681f87f0b5SEric W. Biederman int (*is_seen)(struct ctl_table_set *)) 12691f87f0b5SEric W. Biederman { 12701f87f0b5SEric W. Biederman INIT_LIST_HEAD(&p->list); 12711f87f0b5SEric W. Biederman p->is_seen = is_seen; 12721f87f0b5SEric W. Biederman } 12731f87f0b5SEric W. Biederman 127497324cd8SEric W. Biederman void retire_sysctl_set(struct ctl_table_set *set) 127597324cd8SEric W. Biederman { 127697324cd8SEric W. Biederman WARN_ON(!list_empty(&set->list)); 127797324cd8SEric W. Biederman } 12781f87f0b5SEric W. Biederman 12791e0edd3fSAlexey Dobriyan int __init proc_sys_init(void) 128077b14db5SEric W. Biederman { 1281e1675231SAlexey Dobriyan struct proc_dir_entry *proc_sys_root; 1282e1675231SAlexey Dobriyan 128377b14db5SEric W. Biederman proc_sys_root = proc_mkdir("sys", NULL); 12849043476fSAl Viro proc_sys_root->proc_iops = &proc_sys_dir_operations; 12859043476fSAl Viro proc_sys_root->proc_fops = &proc_sys_dir_file_operations; 128677b14db5SEric W. Biederman proc_sys_root->nlink = 0; 1287de4e83bdSEric W. Biederman 1288de4e83bdSEric W. Biederman return sysctl_init(); 128977b14db5SEric W. Biederman } 1290