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 451f87f0b5SEric W. Biederman /* called under sysctl_lock */ 461f87f0b5SEric W. Biederman static int use_table(struct ctl_table_header *p) 471f87f0b5SEric W. Biederman { 481f87f0b5SEric W. Biederman if (unlikely(p->unregistering)) 491f87f0b5SEric W. Biederman return 0; 501f87f0b5SEric W. Biederman p->used++; 511f87f0b5SEric W. Biederman return 1; 521f87f0b5SEric W. Biederman } 531f87f0b5SEric W. Biederman 541f87f0b5SEric W. Biederman /* called under sysctl_lock */ 551f87f0b5SEric W. Biederman static void unuse_table(struct ctl_table_header *p) 561f87f0b5SEric W. Biederman { 571f87f0b5SEric W. Biederman if (!--p->used) 581f87f0b5SEric W. Biederman if (unlikely(p->unregistering)) 591f87f0b5SEric W. Biederman complete(p->unregistering); 601f87f0b5SEric W. Biederman } 611f87f0b5SEric W. Biederman 621f87f0b5SEric W. Biederman /* called under sysctl_lock, will reacquire if has to wait */ 631f87f0b5SEric W. Biederman static void start_unregistering(struct ctl_table_header *p) 641f87f0b5SEric W. Biederman { 651f87f0b5SEric W. Biederman /* 661f87f0b5SEric W. Biederman * if p->used is 0, nobody will ever touch that entry again; 671f87f0b5SEric W. Biederman * we'll eliminate all paths to it before dropping sysctl_lock 681f87f0b5SEric W. Biederman */ 691f87f0b5SEric W. Biederman if (unlikely(p->used)) { 701f87f0b5SEric W. Biederman struct completion wait; 711f87f0b5SEric W. Biederman init_completion(&wait); 721f87f0b5SEric W. Biederman p->unregistering = &wait; 731f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 741f87f0b5SEric W. Biederman wait_for_completion(&wait); 751f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 761f87f0b5SEric W. Biederman } else { 771f87f0b5SEric W. Biederman /* anything non-NULL; we'll never dereference it */ 781f87f0b5SEric W. Biederman p->unregistering = ERR_PTR(-EINVAL); 791f87f0b5SEric W. Biederman } 801f87f0b5SEric W. Biederman /* 811f87f0b5SEric W. Biederman * do not remove from the list until nobody holds it; walking the 821f87f0b5SEric W. Biederman * list in do_sysctl() relies on that. 831f87f0b5SEric W. Biederman */ 841f87f0b5SEric W. Biederman list_del_init(&p->ctl_entry); 851f87f0b5SEric W. Biederman } 861f87f0b5SEric W. Biederman 871f87f0b5SEric W. Biederman static void sysctl_head_get(struct ctl_table_header *head) 881f87f0b5SEric W. Biederman { 891f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 901f87f0b5SEric W. Biederman head->count++; 911f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 921f87f0b5SEric W. Biederman } 931f87f0b5SEric W. Biederman 941f87f0b5SEric W. Biederman void sysctl_head_put(struct ctl_table_header *head) 951f87f0b5SEric W. Biederman { 961f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 971f87f0b5SEric W. Biederman if (!--head->count) 981f87f0b5SEric W. Biederman kfree_rcu(head, rcu); 991f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 1001f87f0b5SEric W. Biederman } 1011f87f0b5SEric W. Biederman 1021f87f0b5SEric W. Biederman static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) 1031f87f0b5SEric W. Biederman { 1041f87f0b5SEric W. Biederman if (!head) 1051f87f0b5SEric W. Biederman BUG(); 1061f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1071f87f0b5SEric W. Biederman if (!use_table(head)) 1081f87f0b5SEric W. Biederman head = ERR_PTR(-ENOENT); 1091f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 1101f87f0b5SEric W. Biederman return head; 1111f87f0b5SEric W. Biederman } 1121f87f0b5SEric W. Biederman 1131f87f0b5SEric W. Biederman static void sysctl_head_finish(struct ctl_table_header *head) 1141f87f0b5SEric W. Biederman { 1151f87f0b5SEric W. Biederman if (!head) 1161f87f0b5SEric W. Biederman return; 1171f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1181f87f0b5SEric W. Biederman unuse_table(head); 1191f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 1201f87f0b5SEric W. Biederman } 1211f87f0b5SEric W. Biederman 1221f87f0b5SEric W. Biederman static struct ctl_table_set * 1231f87f0b5SEric W. Biederman lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces) 1241f87f0b5SEric W. Biederman { 1251f87f0b5SEric W. Biederman struct ctl_table_set *set = &root->default_set; 1261f87f0b5SEric W. Biederman if (root->lookup) 1271f87f0b5SEric W. Biederman set = root->lookup(root, namespaces); 1281f87f0b5SEric W. Biederman return set; 1291f87f0b5SEric W. Biederman } 1301f87f0b5SEric W. Biederman 1311f87f0b5SEric W. Biederman static struct list_head * 1321f87f0b5SEric W. Biederman lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces) 1331f87f0b5SEric W. Biederman { 1341f87f0b5SEric W. Biederman struct ctl_table_set *set = lookup_header_set(root, namespaces); 1351f87f0b5SEric W. Biederman return &set->list; 1361f87f0b5SEric W. Biederman } 1371f87f0b5SEric W. Biederman 1381f87f0b5SEric W. Biederman static struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces, 1391f87f0b5SEric W. Biederman struct ctl_table_header *prev) 1401f87f0b5SEric W. Biederman { 1411f87f0b5SEric W. Biederman struct ctl_table_root *root; 1421f87f0b5SEric W. Biederman struct list_head *header_list; 1431f87f0b5SEric W. Biederman struct ctl_table_header *head; 1441f87f0b5SEric W. Biederman struct list_head *tmp; 1451f87f0b5SEric W. Biederman 1461f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1471f87f0b5SEric W. Biederman if (prev) { 1481f87f0b5SEric W. Biederman head = prev; 1491f87f0b5SEric W. Biederman tmp = &prev->ctl_entry; 1501f87f0b5SEric W. Biederman unuse_table(prev); 1511f87f0b5SEric W. Biederman goto next; 1521f87f0b5SEric W. Biederman } 1531f87f0b5SEric W. Biederman tmp = &root_table_header.ctl_entry; 1541f87f0b5SEric W. Biederman for (;;) { 1551f87f0b5SEric W. Biederman head = list_entry(tmp, struct ctl_table_header, ctl_entry); 1561f87f0b5SEric W. Biederman 1571f87f0b5SEric W. Biederman if (!use_table(head)) 1581f87f0b5SEric W. Biederman goto next; 1591f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 1601f87f0b5SEric W. Biederman return head; 1611f87f0b5SEric W. Biederman next: 1621f87f0b5SEric W. Biederman root = head->root; 1631f87f0b5SEric W. Biederman tmp = tmp->next; 1641f87f0b5SEric W. Biederman header_list = lookup_header_list(root, namespaces); 1651f87f0b5SEric W. Biederman if (tmp != header_list) 1661f87f0b5SEric W. Biederman continue; 1671f87f0b5SEric W. Biederman 1681f87f0b5SEric W. Biederman do { 1691f87f0b5SEric W. Biederman root = list_entry(root->root_list.next, 1701f87f0b5SEric W. Biederman struct ctl_table_root, root_list); 1711f87f0b5SEric W. Biederman if (root == &sysctl_table_root) 1721f87f0b5SEric W. Biederman goto out; 1731f87f0b5SEric W. Biederman header_list = lookup_header_list(root, namespaces); 1741f87f0b5SEric W. Biederman } while (list_empty(header_list)); 1751f87f0b5SEric W. Biederman tmp = header_list->next; 1761f87f0b5SEric W. Biederman } 1771f87f0b5SEric W. Biederman out: 1781f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 1791f87f0b5SEric W. Biederman return NULL; 1801f87f0b5SEric W. Biederman } 1811f87f0b5SEric W. Biederman 1821f87f0b5SEric W. Biederman static struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev) 1831f87f0b5SEric W. Biederman { 1841f87f0b5SEric W. Biederman return __sysctl_head_next(current->nsproxy, prev); 1851f87f0b5SEric W. Biederman } 1861f87f0b5SEric W. Biederman 1871f87f0b5SEric W. Biederman void register_sysctl_root(struct ctl_table_root *root) 1881f87f0b5SEric W. Biederman { 1891f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1901f87f0b5SEric W. Biederman list_add_tail(&root->root_list, &sysctl_table_root.root_list); 1911f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 1921f87f0b5SEric W. Biederman } 1931f87f0b5SEric W. Biederman 1941f87f0b5SEric W. Biederman /* 1951f87f0b5SEric W. Biederman * sysctl_perm does NOT grant the superuser all rights automatically, because 1961f87f0b5SEric W. Biederman * some sysctl variables are readonly even to root. 1971f87f0b5SEric W. Biederman */ 1981f87f0b5SEric W. Biederman 1991f87f0b5SEric W. Biederman static int test_perm(int mode, int op) 2001f87f0b5SEric W. Biederman { 2011f87f0b5SEric W. Biederman if (!current_euid()) 2021f87f0b5SEric W. Biederman mode >>= 6; 2031f87f0b5SEric W. Biederman else if (in_egroup_p(0)) 2041f87f0b5SEric W. Biederman mode >>= 3; 2051f87f0b5SEric W. Biederman if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) 2061f87f0b5SEric W. Biederman return 0; 2071f87f0b5SEric W. Biederman return -EACCES; 2081f87f0b5SEric W. Biederman } 2091f87f0b5SEric W. Biederman 2101f87f0b5SEric W. Biederman static int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op) 2111f87f0b5SEric W. Biederman { 2121f87f0b5SEric W. Biederman int mode; 2131f87f0b5SEric W. Biederman 2141f87f0b5SEric W. Biederman if (root->permissions) 2151f87f0b5SEric W. Biederman mode = root->permissions(root, current->nsproxy, table); 2161f87f0b5SEric W. Biederman else 2171f87f0b5SEric W. Biederman mode = table->mode; 2181f87f0b5SEric W. Biederman 2191f87f0b5SEric W. Biederman return test_perm(mode, op); 2201f87f0b5SEric W. Biederman } 2211f87f0b5SEric W. Biederman 2229043476fSAl Viro static struct inode *proc_sys_make_inode(struct super_block *sb, 2239043476fSAl Viro struct ctl_table_header *head, struct ctl_table *table) 22477b14db5SEric W. Biederman { 22577b14db5SEric W. Biederman struct inode *inode; 2269043476fSAl Viro struct proc_inode *ei; 22777b14db5SEric W. Biederman 2289043476fSAl Viro inode = new_inode(sb); 22977b14db5SEric W. Biederman if (!inode) 23077b14db5SEric W. Biederman goto out; 23177b14db5SEric W. Biederman 23285fe4025SChristoph Hellwig inode->i_ino = get_next_ino(); 23385fe4025SChristoph Hellwig 2349043476fSAl Viro sysctl_head_get(head); 23577b14db5SEric W. Biederman ei = PROC_I(inode); 2369043476fSAl Viro ei->sysctl = head; 2379043476fSAl Viro ei->sysctl_entry = table; 2389043476fSAl Viro 23977b14db5SEric W. Biederman inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 2409043476fSAl Viro inode->i_mode = table->mode; 2419043476fSAl Viro if (!table->child) { 2429043476fSAl Viro inode->i_mode |= S_IFREG; 24377b14db5SEric W. Biederman inode->i_op = &proc_sys_inode_operations; 24477b14db5SEric W. Biederman inode->i_fop = &proc_sys_file_operations; 2459043476fSAl Viro } else { 2469043476fSAl Viro inode->i_mode |= S_IFDIR; 2479043476fSAl Viro inode->i_op = &proc_sys_dir_operations; 2489043476fSAl Viro inode->i_fop = &proc_sys_dir_file_operations; 2499043476fSAl Viro } 25077b14db5SEric W. Biederman out: 25177b14db5SEric W. Biederman return inode; 25277b14db5SEric W. Biederman } 25377b14db5SEric W. Biederman 2549043476fSAl Viro static struct ctl_table *find_in_table(struct ctl_table *p, struct qstr *name) 25577b14db5SEric W. Biederman { 2562315ffa0SEric W. Biederman for ( ; p->procname; p++) { 25736885d7bSLucas De Marchi if (strlen(p->procname) != name->len) 25877b14db5SEric W. Biederman continue; 25977b14db5SEric W. Biederman 26036885d7bSLucas De Marchi if (memcmp(p->procname, name->name, name->len) != 0) 26177b14db5SEric W. Biederman continue; 26277b14db5SEric W. Biederman 26377b14db5SEric W. Biederman /* I have a match */ 2649043476fSAl Viro return p; 26577b14db5SEric W. Biederman } 26677b14db5SEric W. Biederman return NULL; 26777b14db5SEric W. Biederman } 26877b14db5SEric W. Biederman 26981324364SAdrian Bunk static struct ctl_table_header *grab_header(struct inode *inode) 27077b14db5SEric W. Biederman { 2713cc3e046SEric W. Biederman struct ctl_table_header *head = PROC_I(inode)->sysctl; 2723cc3e046SEric W. Biederman if (!head) 2733cc3e046SEric W. Biederman head = &root_table_header; 2743cc3e046SEric W. Biederman return sysctl_head_grab(head); 27577b14db5SEric W. Biederman } 27677b14db5SEric W. Biederman 27777b14db5SEric W. Biederman static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, 27877b14db5SEric W. Biederman struct nameidata *nd) 27977b14db5SEric W. Biederman { 2809043476fSAl Viro struct ctl_table_header *head = grab_header(dir); 2819043476fSAl Viro struct ctl_table *table = PROC_I(dir)->sysctl_entry; 2829043476fSAl Viro struct ctl_table_header *h = NULL; 2839043476fSAl Viro struct qstr *name = &dentry->d_name; 2849043476fSAl Viro struct ctl_table *p; 28577b14db5SEric W. Biederman struct inode *inode; 2869043476fSAl Viro struct dentry *err = ERR_PTR(-ENOENT); 28777b14db5SEric W. Biederman 2889043476fSAl Viro if (IS_ERR(head)) 2899043476fSAl Viro return ERR_CAST(head); 2909043476fSAl Viro 2919043476fSAl Viro if (table && !table->child) { 2929043476fSAl Viro WARN_ON(1); 2939043476fSAl Viro goto out; 2949043476fSAl Viro } 2959043476fSAl Viro 2969043476fSAl Viro table = table ? table->child : head->ctl_table; 2979043476fSAl Viro 2989043476fSAl Viro p = find_in_table(table, name); 2999043476fSAl Viro if (!p) { 3009043476fSAl Viro for (h = sysctl_head_next(NULL); h; h = sysctl_head_next(h)) { 3019043476fSAl Viro if (h->attached_to != table) 3029043476fSAl Viro continue; 3039043476fSAl Viro p = find_in_table(h->attached_by, name); 3049043476fSAl Viro if (p) 3059043476fSAl Viro break; 3069043476fSAl Viro } 3079043476fSAl Viro } 3089043476fSAl Viro 3099043476fSAl Viro if (!p) 31077b14db5SEric W. Biederman goto out; 31177b14db5SEric W. Biederman 31277b14db5SEric W. Biederman err = ERR_PTR(-ENOMEM); 3139043476fSAl Viro inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); 3149043476fSAl Viro if (h) 3159043476fSAl Viro sysctl_head_finish(h); 3169043476fSAl Viro 31777b14db5SEric W. Biederman if (!inode) 31877b14db5SEric W. Biederman goto out; 31977b14db5SEric W. Biederman 32077b14db5SEric W. Biederman err = NULL; 321fb045adbSNick Piggin d_set_d_op(dentry, &proc_sys_dentry_operations); 32277b14db5SEric W. Biederman d_add(dentry, inode); 32377b14db5SEric W. Biederman 32477b14db5SEric W. Biederman out: 32577b14db5SEric W. Biederman sysctl_head_finish(head); 32677b14db5SEric W. Biederman return err; 32777b14db5SEric W. Biederman } 32877b14db5SEric W. Biederman 3297708bfb1SPavel Emelyanov static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf, 3307708bfb1SPavel Emelyanov size_t count, loff_t *ppos, int write) 33177b14db5SEric W. Biederman { 3329043476fSAl Viro struct inode *inode = filp->f_path.dentry->d_inode; 3339043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 3349043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 3352a2da53bSDavid Howells ssize_t error; 3362a2da53bSDavid Howells size_t res; 33777b14db5SEric W. Biederman 3389043476fSAl Viro if (IS_ERR(head)) 3399043476fSAl Viro return PTR_ERR(head); 34077b14db5SEric W. Biederman 34177b14db5SEric W. Biederman /* 34277b14db5SEric W. Biederman * At this point we know that the sysctl was not unregistered 34377b14db5SEric W. Biederman * and won't be until we finish. 34477b14db5SEric W. Biederman */ 34577b14db5SEric W. Biederman error = -EPERM; 346d7321cd6SPavel Emelyanov if (sysctl_perm(head->root, table, write ? MAY_WRITE : MAY_READ)) 34777b14db5SEric W. Biederman goto out; 34877b14db5SEric W. Biederman 3499043476fSAl Viro /* if that can happen at all, it should be -EINVAL, not -EISDIR */ 3509043476fSAl Viro error = -EINVAL; 3519043476fSAl Viro if (!table->proc_handler) 3529043476fSAl Viro goto out; 3539043476fSAl Viro 35477b14db5SEric W. Biederman /* careful: calling conventions are nasty here */ 35577b14db5SEric W. Biederman res = count; 3568d65af78SAlexey Dobriyan error = table->proc_handler(table, write, buf, &res, ppos); 35777b14db5SEric W. Biederman if (!error) 35877b14db5SEric W. Biederman error = res; 35977b14db5SEric W. Biederman out: 36077b14db5SEric W. Biederman sysctl_head_finish(head); 36177b14db5SEric W. Biederman 36277b14db5SEric W. Biederman return error; 36377b14db5SEric W. Biederman } 36477b14db5SEric W. Biederman 3657708bfb1SPavel Emelyanov static ssize_t proc_sys_read(struct file *filp, char __user *buf, 3667708bfb1SPavel Emelyanov size_t count, loff_t *ppos) 3677708bfb1SPavel Emelyanov { 3687708bfb1SPavel Emelyanov return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0); 3697708bfb1SPavel Emelyanov } 3707708bfb1SPavel Emelyanov 37177b14db5SEric W. Biederman static ssize_t proc_sys_write(struct file *filp, const char __user *buf, 37277b14db5SEric W. Biederman size_t count, loff_t *ppos) 37377b14db5SEric W. Biederman { 3747708bfb1SPavel Emelyanov return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1); 37577b14db5SEric W. Biederman } 37677b14db5SEric W. Biederman 377f1ecf068SLucas De Marchi static int proc_sys_open(struct inode *inode, struct file *filp) 378f1ecf068SLucas De Marchi { 379f1ecf068SLucas De Marchi struct ctl_table *table = PROC_I(inode)->sysctl_entry; 380f1ecf068SLucas De Marchi 381f1ecf068SLucas De Marchi if (table->poll) 382f1ecf068SLucas De Marchi filp->private_data = proc_sys_poll_event(table->poll); 383f1ecf068SLucas De Marchi 384f1ecf068SLucas De Marchi return 0; 385f1ecf068SLucas De Marchi } 386f1ecf068SLucas De Marchi 387f1ecf068SLucas De Marchi static unsigned int proc_sys_poll(struct file *filp, poll_table *wait) 388f1ecf068SLucas De Marchi { 389f1ecf068SLucas De Marchi struct inode *inode = filp->f_path.dentry->d_inode; 390f1ecf068SLucas De Marchi struct ctl_table *table = PROC_I(inode)->sysctl_entry; 391f1ecf068SLucas De Marchi unsigned long event = (unsigned long)filp->private_data; 392f1ecf068SLucas De Marchi unsigned int ret = DEFAULT_POLLMASK; 393f1ecf068SLucas De Marchi 394f1ecf068SLucas De Marchi if (!table->proc_handler) 395f1ecf068SLucas De Marchi goto out; 396f1ecf068SLucas De Marchi 397f1ecf068SLucas De Marchi if (!table->poll) 398f1ecf068SLucas De Marchi goto out; 399f1ecf068SLucas De Marchi 400f1ecf068SLucas De Marchi poll_wait(filp, &table->poll->wait, wait); 401f1ecf068SLucas De Marchi 402f1ecf068SLucas De Marchi if (event != atomic_read(&table->poll->event)) { 403f1ecf068SLucas De Marchi filp->private_data = proc_sys_poll_event(table->poll); 404f1ecf068SLucas De Marchi ret = POLLIN | POLLRDNORM | POLLERR | POLLPRI; 405f1ecf068SLucas De Marchi } 406f1ecf068SLucas De Marchi 407f1ecf068SLucas De Marchi out: 408f1ecf068SLucas De Marchi return ret; 409f1ecf068SLucas De Marchi } 41077b14db5SEric W. Biederman 41177b14db5SEric W. Biederman static int proc_sys_fill_cache(struct file *filp, void *dirent, 4129043476fSAl Viro filldir_t filldir, 4139043476fSAl Viro struct ctl_table_header *head, 4149043476fSAl Viro struct ctl_table *table) 41577b14db5SEric W. Biederman { 41677b14db5SEric W. Biederman struct dentry *child, *dir = filp->f_path.dentry; 41777b14db5SEric W. Biederman struct inode *inode; 41877b14db5SEric W. Biederman struct qstr qname; 41977b14db5SEric W. Biederman ino_t ino = 0; 42077b14db5SEric W. Biederman unsigned type = DT_UNKNOWN; 42177b14db5SEric W. Biederman 42277b14db5SEric W. Biederman qname.name = table->procname; 42377b14db5SEric W. Biederman qname.len = strlen(table->procname); 42477b14db5SEric W. Biederman qname.hash = full_name_hash(qname.name, qname.len); 42577b14db5SEric W. Biederman 42677b14db5SEric W. Biederman child = d_lookup(dir, &qname); 42777b14db5SEric W. Biederman if (!child) { 4289043476fSAl Viro child = d_alloc(dir, &qname); 4299043476fSAl Viro if (child) { 4309043476fSAl Viro inode = proc_sys_make_inode(dir->d_sb, head, table); 4319043476fSAl Viro if (!inode) { 4329043476fSAl Viro dput(child); 4339043476fSAl Viro return -ENOMEM; 4349043476fSAl Viro } else { 435fb045adbSNick Piggin d_set_d_op(child, &proc_sys_dentry_operations); 4369043476fSAl Viro d_add(child, inode); 43777b14db5SEric W. Biederman } 4389043476fSAl Viro } else { 4399043476fSAl Viro return -ENOMEM; 44077b14db5SEric W. Biederman } 44177b14db5SEric W. Biederman } 44277b14db5SEric W. Biederman inode = child->d_inode; 44377b14db5SEric W. Biederman ino = inode->i_ino; 44477b14db5SEric W. Biederman type = inode->i_mode >> 12; 44577b14db5SEric W. Biederman dput(child); 4469043476fSAl Viro return !!filldir(dirent, qname.name, qname.len, filp->f_pos, ino, type); 4479043476fSAl Viro } 4489043476fSAl Viro 4499043476fSAl Viro static int scan(struct ctl_table_header *head, ctl_table *table, 4509043476fSAl Viro unsigned long *pos, struct file *file, 4519043476fSAl Viro void *dirent, filldir_t filldir) 4529043476fSAl Viro { 4539043476fSAl Viro 4542315ffa0SEric W. Biederman for (; table->procname; table++, (*pos)++) { 4559043476fSAl Viro int res; 4569043476fSAl Viro 4579043476fSAl Viro if (*pos < file->f_pos) 4589043476fSAl Viro continue; 4599043476fSAl Viro 4609043476fSAl Viro res = proc_sys_fill_cache(file, dirent, filldir, head, table); 4619043476fSAl Viro if (res) 4629043476fSAl Viro return res; 4639043476fSAl Viro 4649043476fSAl Viro file->f_pos = *pos + 1; 4659043476fSAl Viro } 4669043476fSAl Viro return 0; 46777b14db5SEric W. Biederman } 46877b14db5SEric W. Biederman 46977b14db5SEric W. Biederman static int proc_sys_readdir(struct file *filp, void *dirent, filldir_t filldir) 47077b14db5SEric W. Biederman { 4719043476fSAl Viro struct dentry *dentry = filp->f_path.dentry; 47277b14db5SEric W. Biederman struct inode *inode = dentry->d_inode; 4739043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 4749043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 4759043476fSAl Viro struct ctl_table_header *h = NULL; 47677b14db5SEric W. Biederman unsigned long pos; 4779043476fSAl Viro int ret = -EINVAL; 47877b14db5SEric W. Biederman 4799043476fSAl Viro if (IS_ERR(head)) 4809043476fSAl Viro return PTR_ERR(head); 4819043476fSAl Viro 4829043476fSAl Viro if (table && !table->child) { 4839043476fSAl Viro WARN_ON(1); 48477b14db5SEric W. Biederman goto out; 4859043476fSAl Viro } 4869043476fSAl Viro 4879043476fSAl Viro table = table ? table->child : head->ctl_table; 48877b14db5SEric W. Biederman 48977b14db5SEric W. Biederman ret = 0; 49077b14db5SEric W. Biederman /* Avoid a switch here: arm builds fail with missing __cmpdi2 */ 49177b14db5SEric W. Biederman if (filp->f_pos == 0) { 49277b14db5SEric W. Biederman if (filldir(dirent, ".", 1, filp->f_pos, 49377b14db5SEric W. Biederman inode->i_ino, DT_DIR) < 0) 49477b14db5SEric W. Biederman goto out; 49577b14db5SEric W. Biederman filp->f_pos++; 49677b14db5SEric W. Biederman } 49777b14db5SEric W. Biederman if (filp->f_pos == 1) { 49877b14db5SEric W. Biederman if (filldir(dirent, "..", 2, filp->f_pos, 49977b14db5SEric W. Biederman parent_ino(dentry), DT_DIR) < 0) 50077b14db5SEric W. Biederman goto out; 50177b14db5SEric W. Biederman filp->f_pos++; 50277b14db5SEric W. Biederman } 50377b14db5SEric W. Biederman pos = 2; 50477b14db5SEric W. Biederman 5059043476fSAl Viro ret = scan(head, table, &pos, filp, dirent, filldir); 5069043476fSAl Viro if (ret) 50777b14db5SEric W. Biederman goto out; 5089043476fSAl Viro 5099043476fSAl Viro for (h = sysctl_head_next(NULL); h; h = sysctl_head_next(h)) { 5109043476fSAl Viro if (h->attached_to != table) 5119043476fSAl Viro continue; 5129043476fSAl Viro ret = scan(h, h->attached_by, &pos, filp, dirent, filldir); 5139043476fSAl Viro if (ret) { 5149043476fSAl Viro sysctl_head_finish(h); 5159043476fSAl Viro break; 51677b14db5SEric W. Biederman } 51777b14db5SEric W. Biederman } 51877b14db5SEric W. Biederman ret = 1; 51977b14db5SEric W. Biederman out: 52077b14db5SEric W. Biederman sysctl_head_finish(head); 52177b14db5SEric W. Biederman return ret; 52277b14db5SEric W. Biederman } 52377b14db5SEric W. Biederman 52410556cb2SAl Viro static int proc_sys_permission(struct inode *inode, int mask) 52577b14db5SEric W. Biederman { 52677b14db5SEric W. Biederman /* 52777b14db5SEric W. Biederman * sysctl entries that are not writeable, 52877b14db5SEric W. Biederman * are _NOT_ writeable, capabilities or not. 52977b14db5SEric W. Biederman */ 530f696a365SMiklos Szeredi struct ctl_table_header *head; 531f696a365SMiklos Szeredi struct ctl_table *table; 53277b14db5SEric W. Biederman int error; 53377b14db5SEric W. Biederman 534f696a365SMiklos Szeredi /* Executable files are not allowed under /proc/sys/ */ 535f696a365SMiklos Szeredi if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) 536f696a365SMiklos Szeredi return -EACCES; 537f696a365SMiklos Szeredi 538f696a365SMiklos Szeredi head = grab_header(inode); 5399043476fSAl Viro if (IS_ERR(head)) 5409043476fSAl Viro return PTR_ERR(head); 54177b14db5SEric W. Biederman 542f696a365SMiklos Szeredi table = PROC_I(inode)->sysctl_entry; 5439043476fSAl Viro if (!table) /* global root - r-xr-xr-x */ 5449043476fSAl Viro error = mask & MAY_WRITE ? -EACCES : 0; 5459043476fSAl Viro else /* Use the permissions on the sysctl table entry */ 5461fc0f78cSAl Viro error = sysctl_perm(head->root, table, mask & ~MAY_NOT_BLOCK); 5479043476fSAl Viro 54877b14db5SEric W. Biederman sysctl_head_finish(head); 54977b14db5SEric W. Biederman return error; 55077b14db5SEric W. Biederman } 55177b14db5SEric W. Biederman 55277b14db5SEric W. Biederman static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr) 55377b14db5SEric W. Biederman { 55477b14db5SEric W. Biederman struct inode *inode = dentry->d_inode; 55577b14db5SEric W. Biederman int error; 55677b14db5SEric W. Biederman 55777b14db5SEric W. Biederman if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) 55877b14db5SEric W. Biederman return -EPERM; 55977b14db5SEric W. Biederman 56077b14db5SEric W. Biederman error = inode_change_ok(inode, attr); 5611025774cSChristoph Hellwig if (error) 56277b14db5SEric W. Biederman return error; 5631025774cSChristoph Hellwig 5641025774cSChristoph Hellwig if ((attr->ia_valid & ATTR_SIZE) && 5651025774cSChristoph Hellwig attr->ia_size != i_size_read(inode)) { 5661025774cSChristoph Hellwig error = vmtruncate(inode, attr->ia_size); 5671025774cSChristoph Hellwig if (error) 5681025774cSChristoph Hellwig return error; 5691025774cSChristoph Hellwig } 5701025774cSChristoph Hellwig 5711025774cSChristoph Hellwig setattr_copy(inode, attr); 5721025774cSChristoph Hellwig mark_inode_dirty(inode); 5731025774cSChristoph Hellwig return 0; 57477b14db5SEric W. Biederman } 57577b14db5SEric W. Biederman 5769043476fSAl Viro static int proc_sys_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 5779043476fSAl Viro { 5789043476fSAl Viro struct inode *inode = dentry->d_inode; 5799043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 5809043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 5819043476fSAl Viro 5829043476fSAl Viro if (IS_ERR(head)) 5839043476fSAl Viro return PTR_ERR(head); 5849043476fSAl Viro 5859043476fSAl Viro generic_fillattr(inode, stat); 5869043476fSAl Viro if (table) 5879043476fSAl Viro stat->mode = (stat->mode & S_IFMT) | table->mode; 5889043476fSAl Viro 5899043476fSAl Viro sysctl_head_finish(head); 5909043476fSAl Viro return 0; 5919043476fSAl Viro } 5929043476fSAl Viro 59377b14db5SEric W. Biederman static const struct file_operations proc_sys_file_operations = { 594f1ecf068SLucas De Marchi .open = proc_sys_open, 595f1ecf068SLucas De Marchi .poll = proc_sys_poll, 59677b14db5SEric W. Biederman .read = proc_sys_read, 59777b14db5SEric W. Biederman .write = proc_sys_write, 5986038f373SArnd Bergmann .llseek = default_llseek, 5999043476fSAl Viro }; 6009043476fSAl Viro 6019043476fSAl Viro static const struct file_operations proc_sys_dir_file_operations = { 602887df078SPavel Emelyanov .read = generic_read_dir, 60377b14db5SEric W. Biederman .readdir = proc_sys_readdir, 6043222a3e5SChristoph Hellwig .llseek = generic_file_llseek, 60577b14db5SEric W. Biederman }; 60677b14db5SEric W. Biederman 60703a44825SJan Engelhardt static const struct inode_operations proc_sys_inode_operations = { 6089043476fSAl Viro .permission = proc_sys_permission, 6099043476fSAl Viro .setattr = proc_sys_setattr, 6109043476fSAl Viro .getattr = proc_sys_getattr, 6119043476fSAl Viro }; 6129043476fSAl Viro 6139043476fSAl Viro static const struct inode_operations proc_sys_dir_operations = { 61477b14db5SEric W. Biederman .lookup = proc_sys_lookup, 61577b14db5SEric W. Biederman .permission = proc_sys_permission, 61677b14db5SEric W. Biederman .setattr = proc_sys_setattr, 6179043476fSAl Viro .getattr = proc_sys_getattr, 61877b14db5SEric W. Biederman }; 61977b14db5SEric W. Biederman 62077b14db5SEric W. Biederman static int proc_sys_revalidate(struct dentry *dentry, struct nameidata *nd) 62177b14db5SEric W. Biederman { 62234286d66SNick Piggin if (nd->flags & LOOKUP_RCU) 62334286d66SNick Piggin return -ECHILD; 6249043476fSAl Viro return !PROC_I(dentry->d_inode)->sysctl->unregistering; 6259043476fSAl Viro } 6269043476fSAl Viro 627fe15ce44SNick Piggin static int proc_sys_delete(const struct dentry *dentry) 6289043476fSAl Viro { 6299043476fSAl Viro return !!PROC_I(dentry->d_inode)->sysctl->unregistering; 6309043476fSAl Viro } 6319043476fSAl Viro 6321f87f0b5SEric W. Biederman static int sysctl_is_seen(struct ctl_table_header *p) 6331f87f0b5SEric W. Biederman { 6341f87f0b5SEric W. Biederman struct ctl_table_set *set = p->set; 6351f87f0b5SEric W. Biederman int res; 6361f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 6371f87f0b5SEric W. Biederman if (p->unregistering) 6381f87f0b5SEric W. Biederman res = 0; 6391f87f0b5SEric W. Biederman else if (!set->is_seen) 6401f87f0b5SEric W. Biederman res = 1; 6411f87f0b5SEric W. Biederman else 6421f87f0b5SEric W. Biederman res = set->is_seen(set); 6431f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 6441f87f0b5SEric W. Biederman return res; 6451f87f0b5SEric W. Biederman } 6461f87f0b5SEric W. Biederman 647621e155aSNick Piggin static int proc_sys_compare(const struct dentry *parent, 648621e155aSNick Piggin const struct inode *pinode, 649621e155aSNick Piggin const struct dentry *dentry, const struct inode *inode, 650621e155aSNick Piggin unsigned int len, const char *str, const struct qstr *name) 6519043476fSAl Viro { 652dfef6dcdSAl Viro struct ctl_table_header *head; 65331e6b01fSNick Piggin /* Although proc doesn't have negative dentries, rcu-walk means 65431e6b01fSNick Piggin * that inode here can be NULL */ 655dfef6dcdSAl Viro /* AV: can it, indeed? */ 65631e6b01fSNick Piggin if (!inode) 657dfef6dcdSAl Viro return 1; 658621e155aSNick Piggin if (name->len != len) 6599043476fSAl Viro return 1; 660621e155aSNick Piggin if (memcmp(name->name, str, len)) 6619043476fSAl Viro return 1; 662dfef6dcdSAl Viro head = rcu_dereference(PROC_I(inode)->sysctl); 663dfef6dcdSAl Viro return !head || !sysctl_is_seen(head); 66477b14db5SEric W. Biederman } 66577b14db5SEric W. Biederman 666d72f71ebSAl Viro static const struct dentry_operations proc_sys_dentry_operations = { 66777b14db5SEric W. Biederman .d_revalidate = proc_sys_revalidate, 6689043476fSAl Viro .d_delete = proc_sys_delete, 6699043476fSAl Viro .d_compare = proc_sys_compare, 67077b14db5SEric W. Biederman }; 67177b14db5SEric W. Biederman 6721f87f0b5SEric W. Biederman static struct ctl_table *is_branch_in(struct ctl_table *branch, 6731f87f0b5SEric W. Biederman struct ctl_table *table) 6741f87f0b5SEric W. Biederman { 6751f87f0b5SEric W. Biederman struct ctl_table *p; 6761f87f0b5SEric W. Biederman const char *s = branch->procname; 6771f87f0b5SEric W. Biederman 6781f87f0b5SEric W. Biederman /* branch should have named subdirectory as its first element */ 6791f87f0b5SEric W. Biederman if (!s || !branch->child) 6801f87f0b5SEric W. Biederman return NULL; 6811f87f0b5SEric W. Biederman 6821f87f0b5SEric W. Biederman /* ... and nothing else */ 6831f87f0b5SEric W. Biederman if (branch[1].procname) 6841f87f0b5SEric W. Biederman return NULL; 6851f87f0b5SEric W. Biederman 6861f87f0b5SEric W. Biederman /* table should contain subdirectory with the same name */ 6871f87f0b5SEric W. Biederman for (p = table; p->procname; p++) { 6881f87f0b5SEric W. Biederman if (!p->child) 6891f87f0b5SEric W. Biederman continue; 6901f87f0b5SEric W. Biederman if (p->procname && strcmp(p->procname, s) == 0) 6911f87f0b5SEric W. Biederman return p; 6921f87f0b5SEric W. Biederman } 6931f87f0b5SEric W. Biederman return NULL; 6941f87f0b5SEric W. Biederman } 6951f87f0b5SEric W. Biederman 6961f87f0b5SEric W. Biederman /* see if attaching q to p would be an improvement */ 6971f87f0b5SEric W. Biederman static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q) 6981f87f0b5SEric W. Biederman { 6991f87f0b5SEric W. Biederman struct ctl_table *to = p->ctl_table, *by = q->ctl_table; 7001f87f0b5SEric W. Biederman struct ctl_table *next; 7011f87f0b5SEric W. Biederman int is_better = 0; 7021f87f0b5SEric W. Biederman int not_in_parent = !p->attached_by; 7031f87f0b5SEric W. Biederman 7041f87f0b5SEric W. Biederman while ((next = is_branch_in(by, to)) != NULL) { 7051f87f0b5SEric W. Biederman if (by == q->attached_by) 7061f87f0b5SEric W. Biederman is_better = 1; 7071f87f0b5SEric W. Biederman if (to == p->attached_by) 7081f87f0b5SEric W. Biederman not_in_parent = 1; 7091f87f0b5SEric W. Biederman by = by->child; 7101f87f0b5SEric W. Biederman to = next->child; 7111f87f0b5SEric W. Biederman } 7121f87f0b5SEric W. Biederman 7131f87f0b5SEric W. Biederman if (is_better && not_in_parent) { 7141f87f0b5SEric W. Biederman q->attached_by = by; 7151f87f0b5SEric W. Biederman q->attached_to = to; 7161f87f0b5SEric W. Biederman q->parent = p; 7171f87f0b5SEric W. Biederman } 7181f87f0b5SEric W. Biederman } 7191f87f0b5SEric W. Biederman 7207c60c48fSEric W. Biederman static int sysctl_check_table_dups(const char *path, struct ctl_table *old, 7211f87f0b5SEric W. Biederman struct ctl_table *table) 7221f87f0b5SEric W. Biederman { 7237c60c48fSEric W. Biederman struct ctl_table *entry, *test; 7241f87f0b5SEric W. Biederman int error = 0; 7251f87f0b5SEric W. Biederman 7267c60c48fSEric W. Biederman for (entry = old; entry->procname; entry++) { 7277c60c48fSEric W. Biederman for (test = table; test->procname; test++) { 7287c60c48fSEric W. Biederman if (strcmp(entry->procname, test->procname) == 0) { 7297c60c48fSEric W. Biederman printk(KERN_ERR "sysctl duplicate entry: %s/%s\n", 7307c60c48fSEric W. Biederman path, test->procname); 7317c60c48fSEric W. Biederman error = -EEXIST; 7321f87f0b5SEric W. Biederman } 7337c60c48fSEric W. Biederman } 7347c60c48fSEric W. Biederman } 7357c60c48fSEric W. Biederman return error; 7367c60c48fSEric W. Biederman } 7377c60c48fSEric W. Biederman 7387c60c48fSEric W. Biederman static int sysctl_check_dups(struct nsproxy *namespaces, 7397c60c48fSEric W. Biederman struct ctl_table_header *header, 7407c60c48fSEric W. Biederman const char *path, struct ctl_table *table) 7417c60c48fSEric W. Biederman { 7427c60c48fSEric W. Biederman struct ctl_table_root *root; 7437c60c48fSEric W. Biederman struct ctl_table_set *set; 7447c60c48fSEric W. Biederman struct ctl_table_header *dir_head, *head; 7457c60c48fSEric W. Biederman struct ctl_table *dir_table; 7467c60c48fSEric W. Biederman int error = 0; 7477c60c48fSEric W. Biederman 7487c60c48fSEric W. Biederman /* No dups if we are the only member of our directory */ 7497c60c48fSEric W. Biederman if (header->attached_by != table) 7507c60c48fSEric W. Biederman return 0; 7517c60c48fSEric W. Biederman 7527c60c48fSEric W. Biederman dir_head = header->parent; 7537c60c48fSEric W. Biederman dir_table = header->attached_to; 7547c60c48fSEric W. Biederman 7557c60c48fSEric W. Biederman error = sysctl_check_table_dups(path, dir_table, table); 7567c60c48fSEric W. Biederman 7577c60c48fSEric W. Biederman root = &sysctl_table_root; 7587c60c48fSEric W. Biederman do { 7597c60c48fSEric W. Biederman set = lookup_header_set(root, namespaces); 7607c60c48fSEric W. Biederman 7617c60c48fSEric W. Biederman list_for_each_entry(head, &set->list, ctl_entry) { 7627c60c48fSEric W. Biederman if (head->unregistering) 7637c60c48fSEric W. Biederman continue; 7647c60c48fSEric W. Biederman if (head->attached_to != dir_table) 7657c60c48fSEric W. Biederman continue; 7667c60c48fSEric W. Biederman error = sysctl_check_table_dups(path, head->attached_by, 7677c60c48fSEric W. Biederman table); 7687c60c48fSEric W. Biederman } 7697c60c48fSEric W. Biederman root = list_entry(root->root_list.next, 7707c60c48fSEric W. Biederman struct ctl_table_root, root_list); 7717c60c48fSEric W. Biederman } while (root != &sysctl_table_root); 7727c60c48fSEric W. Biederman return error; 7737c60c48fSEric W. Biederman } 7747c60c48fSEric W. Biederman 7757c60c48fSEric W. Biederman static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...) 7767c60c48fSEric W. Biederman { 7777c60c48fSEric W. Biederman struct va_format vaf; 7787c60c48fSEric W. Biederman va_list args; 7797c60c48fSEric W. Biederman 7807c60c48fSEric W. Biederman va_start(args, fmt); 7817c60c48fSEric W. Biederman vaf.fmt = fmt; 7827c60c48fSEric W. Biederman vaf.va = &args; 7837c60c48fSEric W. Biederman 7847c60c48fSEric W. Biederman printk(KERN_ERR "sysctl table check failed: %s/%s %pV\n", 7857c60c48fSEric W. Biederman path, table->procname, &vaf); 7867c60c48fSEric W. Biederman 7877c60c48fSEric W. Biederman va_end(args); 7887c60c48fSEric W. Biederman return -EINVAL; 7897c60c48fSEric W. Biederman } 7907c60c48fSEric W. Biederman 7917c60c48fSEric W. Biederman static int sysctl_check_table(const char *path, struct ctl_table *table) 7927c60c48fSEric W. Biederman { 7937c60c48fSEric W. Biederman int err = 0; 7947c60c48fSEric W. Biederman for (; table->procname; table++) { 7957c60c48fSEric W. Biederman if (table->child) 7967c60c48fSEric W. Biederman err = sysctl_err(path, table, "Not a file"); 7977c60c48fSEric W. Biederman 7981f87f0b5SEric W. Biederman if ((table->proc_handler == proc_dostring) || 7991f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec) || 8001f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_minmax) || 8011f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_jiffies) || 8021f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_userhz_jiffies) || 8031f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_ms_jiffies) || 8041f87f0b5SEric W. Biederman (table->proc_handler == proc_doulongvec_minmax) || 8051f87f0b5SEric W. Biederman (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) { 8061f87f0b5SEric W. Biederman if (!table->data) 8077c60c48fSEric W. Biederman err = sysctl_err(path, table, "No data"); 8081f87f0b5SEric W. Biederman if (!table->maxlen) 8097c60c48fSEric W. Biederman err = sysctl_err(path, table, "No maxlen"); 8101f87f0b5SEric W. Biederman } 8111f87f0b5SEric W. Biederman if (!table->proc_handler) 8127c60c48fSEric W. Biederman err = sysctl_err(path, table, "No proc_handler"); 8137c60c48fSEric W. Biederman 8147c60c48fSEric W. Biederman if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode) 8157c60c48fSEric W. Biederman err = sysctl_err(path, table, "bogus .mode 0%o", 8167c60c48fSEric W. Biederman table->mode); 8171f87f0b5SEric W. Biederman } 8187c60c48fSEric W. Biederman return err; 8191f87f0b5SEric W. Biederman } 8201f87f0b5SEric W. Biederman 8211f87f0b5SEric W. Biederman /** 822f728019bSEric W. Biederman * __register_sysctl_table - register a leaf sysctl table 8231f87f0b5SEric W. Biederman * @root: List of sysctl headers to register on 8241f87f0b5SEric W. Biederman * @namespaces: Data to compute which lists of sysctl entries are visible 8251f87f0b5SEric W. Biederman * @path: The path to the directory the sysctl table is in. 8261f87f0b5SEric W. Biederman * @table: the top-level table structure 8271f87f0b5SEric W. Biederman * 8281f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 8291f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 8301f87f0b5SEric W. Biederman * 8311f87f0b5SEric W. Biederman * The members of the &struct ctl_table structure are used as follows: 8321f87f0b5SEric W. Biederman * 8331f87f0b5SEric W. Biederman * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not 8341f87f0b5SEric W. Biederman * enter a sysctl file 8351f87f0b5SEric W. Biederman * 8361f87f0b5SEric W. Biederman * data - a pointer to data for use by proc_handler 8371f87f0b5SEric W. Biederman * 8381f87f0b5SEric W. Biederman * maxlen - the maximum size in bytes of the data 8391f87f0b5SEric W. Biederman * 840f728019bSEric W. Biederman * mode - the file permissions for the /proc/sys file 8411f87f0b5SEric W. Biederman * 842f728019bSEric W. Biederman * child - must be %NULL. 8431f87f0b5SEric W. Biederman * 8441f87f0b5SEric W. Biederman * proc_handler - the text handler routine (described below) 8451f87f0b5SEric W. Biederman * 8461f87f0b5SEric W. Biederman * extra1, extra2 - extra pointers usable by the proc handler routines 8471f87f0b5SEric W. Biederman * 8481f87f0b5SEric W. Biederman * Leaf nodes in the sysctl tree will be represented by a single file 8491f87f0b5SEric W. Biederman * under /proc; non-leaf nodes will be represented by directories. 8501f87f0b5SEric W. Biederman * 851f728019bSEric W. Biederman * There must be a proc_handler routine for any terminal nodes. 852f728019bSEric W. Biederman * Several default handlers are available to cover common cases - 8531f87f0b5SEric W. Biederman * 8541f87f0b5SEric W. Biederman * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), 8551f87f0b5SEric W. Biederman * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 8561f87f0b5SEric W. Biederman * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() 8571f87f0b5SEric W. Biederman * 8581f87f0b5SEric W. Biederman * It is the handler's job to read the input buffer from user memory 8591f87f0b5SEric W. Biederman * and process it. The handler should return 0 on success. 8601f87f0b5SEric W. Biederman * 8611f87f0b5SEric W. Biederman * This routine returns %NULL on a failure to register, and a pointer 8621f87f0b5SEric W. Biederman * to the table header on success. 8631f87f0b5SEric W. Biederman */ 8646e9d5164SEric W. Biederman struct ctl_table_header *__register_sysctl_table( 8651f87f0b5SEric W. Biederman struct ctl_table_root *root, 8661f87f0b5SEric W. Biederman struct nsproxy *namespaces, 8676e9d5164SEric W. Biederman const char *path, struct ctl_table *table) 8681f87f0b5SEric W. Biederman { 8691f87f0b5SEric W. Biederman struct ctl_table_header *header; 8701f87f0b5SEric W. Biederman struct ctl_table *new, **prevp; 8716e9d5164SEric W. Biederman const char *name, *nextname; 8726e9d5164SEric W. Biederman unsigned int npath = 0; 8731f87f0b5SEric W. Biederman struct ctl_table_set *set; 874f05e53a7SEric W. Biederman size_t path_bytes = 0; 875f05e53a7SEric W. Biederman char *new_name; 8761f87f0b5SEric W. Biederman 8771f87f0b5SEric W. Biederman /* Count the path components */ 8786e9d5164SEric W. Biederman for (name = path; name; name = nextname) { 8796e9d5164SEric W. Biederman int namelen; 8806e9d5164SEric W. Biederman nextname = strchr(name, '/'); 8816e9d5164SEric W. Biederman if (nextname) { 8826e9d5164SEric W. Biederman namelen = nextname - name; 8836e9d5164SEric W. Biederman nextname++; 8846e9d5164SEric W. Biederman } else { 8856e9d5164SEric W. Biederman namelen = strlen(name); 8866e9d5164SEric W. Biederman } 8876e9d5164SEric W. Biederman if (namelen == 0) 8886e9d5164SEric W. Biederman continue; 8896e9d5164SEric W. Biederman path_bytes += namelen + 1; 8906e9d5164SEric W. Biederman npath++; 8916e9d5164SEric W. Biederman } 8921f87f0b5SEric W. Biederman 8931f87f0b5SEric W. Biederman /* 8941f87f0b5SEric W. Biederman * For each path component, allocate a 2-element ctl_table array. 8951f87f0b5SEric W. Biederman * The first array element will be filled with the sysctl entry 8961f87f0b5SEric W. Biederman * for this, the second will be the sentinel (procname == 0). 8971f87f0b5SEric W. Biederman * 8981f87f0b5SEric W. Biederman * We allocate everything in one go so that we don't have to 8991f87f0b5SEric W. Biederman * worry about freeing additional memory in unregister_sysctl_table. 9001f87f0b5SEric W. Biederman */ 901f05e53a7SEric W. Biederman header = kzalloc(sizeof(struct ctl_table_header) + path_bytes + 9021f87f0b5SEric W. Biederman (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL); 9031f87f0b5SEric W. Biederman if (!header) 9041f87f0b5SEric W. Biederman return NULL; 9051f87f0b5SEric W. Biederman 9061f87f0b5SEric W. Biederman new = (struct ctl_table *) (header + 1); 907f05e53a7SEric W. Biederman new_name = (char *)(new + (2 * npath)); 9081f87f0b5SEric W. Biederman 9091f87f0b5SEric W. Biederman /* Now connect the dots */ 9101f87f0b5SEric W. Biederman prevp = &header->ctl_table; 9116e9d5164SEric W. Biederman for (name = path; name; name = nextname) { 9126e9d5164SEric W. Biederman int namelen; 9136e9d5164SEric W. Biederman nextname = strchr(name, '/'); 9146e9d5164SEric W. Biederman if (nextname) { 9156e9d5164SEric W. Biederman namelen = nextname - name; 9166e9d5164SEric W. Biederman nextname++; 9176e9d5164SEric W. Biederman } else { 9186e9d5164SEric W. Biederman namelen = strlen(name); 9196e9d5164SEric W. Biederman } 9206e9d5164SEric W. Biederman if (namelen == 0) 9216e9d5164SEric W. Biederman continue; 9226e9d5164SEric W. Biederman memcpy(new_name, name, namelen); 9236e9d5164SEric W. Biederman new_name[namelen] = '\0'; 9246e9d5164SEric W. Biederman 925f05e53a7SEric W. Biederman new->procname = new_name; 9261f87f0b5SEric W. Biederman new->mode = 0555; 9271f87f0b5SEric W. Biederman 9281f87f0b5SEric W. Biederman *prevp = new; 9291f87f0b5SEric W. Biederman prevp = &new->child; 9301f87f0b5SEric W. Biederman 9311f87f0b5SEric W. Biederman new += 2; 9326e9d5164SEric W. Biederman new_name += namelen + 1; 9331f87f0b5SEric W. Biederman } 9341f87f0b5SEric W. Biederman *prevp = table; 9351f87f0b5SEric W. Biederman header->ctl_table_arg = table; 9361f87f0b5SEric W. Biederman 9371f87f0b5SEric W. Biederman INIT_LIST_HEAD(&header->ctl_entry); 9381f87f0b5SEric W. Biederman header->used = 0; 9391f87f0b5SEric W. Biederman header->unregistering = NULL; 9401f87f0b5SEric W. Biederman header->root = root; 9411f87f0b5SEric W. Biederman header->count = 1; 942938aaa4fSEric W. Biederman header->nreg = 1; 9437c60c48fSEric W. Biederman if (sysctl_check_table(path, table)) 9447c60c48fSEric W. Biederman goto fail; 9458d6ecfccSEric W. Biederman 9461f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 9471f87f0b5SEric W. Biederman header->set = lookup_header_set(root, namespaces); 9481f87f0b5SEric W. Biederman header->attached_by = header->ctl_table; 9491f87f0b5SEric W. Biederman header->attached_to = root_table; 9501f87f0b5SEric W. Biederman header->parent = &root_table_header; 951bd295b56SEric W. Biederman set = header->set; 952bd295b56SEric W. Biederman root = header->root; 953bd295b56SEric W. Biederman for (;;) { 9541f87f0b5SEric W. Biederman struct ctl_table_header *p; 9551f87f0b5SEric W. Biederman list_for_each_entry(p, &set->list, ctl_entry) { 9561f87f0b5SEric W. Biederman if (p->unregistering) 9571f87f0b5SEric W. Biederman continue; 9581f87f0b5SEric W. Biederman try_attach(p, header); 9591f87f0b5SEric W. Biederman } 960bd295b56SEric W. Biederman if (root == &sysctl_table_root) 961bd295b56SEric W. Biederman break; 962bd295b56SEric W. Biederman root = list_entry(root->root_list.prev, 963bd295b56SEric W. Biederman struct ctl_table_root, root_list); 964bd295b56SEric W. Biederman set = lookup_header_set(root, namespaces); 9651f87f0b5SEric W. Biederman } 9667c60c48fSEric W. Biederman if (sysctl_check_dups(namespaces, header, path, table)) 9677c60c48fSEric W. Biederman goto fail_locked; 9681f87f0b5SEric W. Biederman header->parent->count++; 9691f87f0b5SEric W. Biederman list_add_tail(&header->ctl_entry, &header->set->list); 9701f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 9711f87f0b5SEric W. Biederman 9721f87f0b5SEric W. Biederman return header; 9737c60c48fSEric W. Biederman fail_locked: 9747c60c48fSEric W. Biederman spin_unlock(&sysctl_lock); 9757c60c48fSEric W. Biederman fail: 9767c60c48fSEric W. Biederman kfree(header); 9777c60c48fSEric W. Biederman dump_stack(); 9787c60c48fSEric W. Biederman return NULL; 9791f87f0b5SEric W. Biederman } 9801f87f0b5SEric W. Biederman 9816e9d5164SEric W. Biederman static char *append_path(const char *path, char *pos, const char *name) 9826e9d5164SEric W. Biederman { 9836e9d5164SEric W. Biederman int namelen; 9846e9d5164SEric W. Biederman namelen = strlen(name); 9856e9d5164SEric W. Biederman if (((pos - path) + namelen + 2) >= PATH_MAX) 9866e9d5164SEric W. Biederman return NULL; 9876e9d5164SEric W. Biederman memcpy(pos, name, namelen); 9886e9d5164SEric W. Biederman pos[namelen] = '/'; 9896e9d5164SEric W. Biederman pos[namelen + 1] = '\0'; 9906e9d5164SEric W. Biederman pos += namelen + 1; 9916e9d5164SEric W. Biederman return pos; 9926e9d5164SEric W. Biederman } 9936e9d5164SEric W. Biederman 994f728019bSEric W. Biederman static int count_subheaders(struct ctl_table *table) 995f728019bSEric W. Biederman { 996f728019bSEric W. Biederman int has_files = 0; 997f728019bSEric W. Biederman int nr_subheaders = 0; 998f728019bSEric W. Biederman struct ctl_table *entry; 999f728019bSEric W. Biederman 1000f728019bSEric W. Biederman /* special case: no directory and empty directory */ 1001f728019bSEric W. Biederman if (!table || !table->procname) 1002f728019bSEric W. Biederman return 1; 1003f728019bSEric W. Biederman 1004f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1005f728019bSEric W. Biederman if (entry->child) 1006f728019bSEric W. Biederman nr_subheaders += count_subheaders(entry->child); 1007f728019bSEric W. Biederman else 1008f728019bSEric W. Biederman has_files = 1; 1009f728019bSEric W. Biederman } 1010f728019bSEric W. Biederman return nr_subheaders + has_files; 1011f728019bSEric W. Biederman } 1012f728019bSEric W. Biederman 1013f728019bSEric W. Biederman static int register_leaf_sysctl_tables(const char *path, char *pos, 1014f728019bSEric W. Biederman struct ctl_table_header ***subheader, 1015f728019bSEric W. Biederman struct ctl_table_root *root, struct nsproxy *namespaces, 1016f728019bSEric W. Biederman struct ctl_table *table) 1017f728019bSEric W. Biederman { 1018f728019bSEric W. Biederman struct ctl_table *ctl_table_arg = NULL; 1019f728019bSEric W. Biederman struct ctl_table *entry, *files; 1020f728019bSEric W. Biederman int nr_files = 0; 1021f728019bSEric W. Biederman int nr_dirs = 0; 1022f728019bSEric W. Biederman int err = -ENOMEM; 1023f728019bSEric W. Biederman 1024f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1025f728019bSEric W. Biederman if (entry->child) 1026f728019bSEric W. Biederman nr_dirs++; 1027f728019bSEric W. Biederman else 1028f728019bSEric W. Biederman nr_files++; 1029f728019bSEric W. Biederman } 1030f728019bSEric W. Biederman 1031f728019bSEric W. Biederman files = table; 1032f728019bSEric W. Biederman /* If there are mixed files and directories we need a new table */ 1033f728019bSEric W. Biederman if (nr_dirs && nr_files) { 1034f728019bSEric W. Biederman struct ctl_table *new; 1035f728019bSEric W. Biederman files = kzalloc(sizeof(struct ctl_table) * (nr_files + 1), 1036f728019bSEric W. Biederman GFP_KERNEL); 1037f728019bSEric W. Biederman if (!files) 1038f728019bSEric W. Biederman goto out; 1039f728019bSEric W. Biederman 1040f728019bSEric W. Biederman ctl_table_arg = files; 1041f728019bSEric W. Biederman for (new = files, entry = table; entry->procname; entry++) { 1042f728019bSEric W. Biederman if (entry->child) 1043f728019bSEric W. Biederman continue; 1044f728019bSEric W. Biederman *new = *entry; 1045f728019bSEric W. Biederman new++; 1046f728019bSEric W. Biederman } 1047f728019bSEric W. Biederman } 1048f728019bSEric W. Biederman 1049f728019bSEric W. Biederman /* Register everything except a directory full of subdirectories */ 1050f728019bSEric W. Biederman if (nr_files || !nr_dirs) { 1051f728019bSEric W. Biederman struct ctl_table_header *header; 1052f728019bSEric W. Biederman header = __register_sysctl_table(root, namespaces, path, files); 1053f728019bSEric W. Biederman if (!header) { 1054f728019bSEric W. Biederman kfree(ctl_table_arg); 1055f728019bSEric W. Biederman goto out; 1056f728019bSEric W. Biederman } 1057f728019bSEric W. Biederman 1058f728019bSEric W. Biederman /* Remember if we need to free the file table */ 1059f728019bSEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1060f728019bSEric W. Biederman **subheader = header; 1061f728019bSEric W. Biederman (*subheader)++; 1062f728019bSEric W. Biederman } 1063f728019bSEric W. Biederman 1064f728019bSEric W. Biederman /* Recurse into the subdirectories. */ 1065f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1066f728019bSEric W. Biederman char *child_pos; 1067f728019bSEric W. Biederman 1068f728019bSEric W. Biederman if (!entry->child) 1069f728019bSEric W. Biederman continue; 1070f728019bSEric W. Biederman 1071f728019bSEric W. Biederman err = -ENAMETOOLONG; 1072f728019bSEric W. Biederman child_pos = append_path(path, pos, entry->procname); 1073f728019bSEric W. Biederman if (!child_pos) 1074f728019bSEric W. Biederman goto out; 1075f728019bSEric W. Biederman 1076f728019bSEric W. Biederman err = register_leaf_sysctl_tables(path, child_pos, subheader, 1077f728019bSEric W. Biederman root, namespaces, entry->child); 1078f728019bSEric W. Biederman pos[0] = '\0'; 1079f728019bSEric W. Biederman if (err) 1080f728019bSEric W. Biederman goto out; 1081f728019bSEric W. Biederman } 1082f728019bSEric W. Biederman err = 0; 1083f728019bSEric W. Biederman out: 1084f728019bSEric W. Biederman /* On failure our caller will unregister all registered subheaders */ 1085f728019bSEric W. Biederman return err; 1086f728019bSEric W. Biederman } 1087f728019bSEric W. Biederman 10886e9d5164SEric W. Biederman /** 10896e9d5164SEric W. Biederman * __register_sysctl_paths - register a sysctl table hierarchy 10906e9d5164SEric W. Biederman * @root: List of sysctl headers to register on 10916e9d5164SEric W. Biederman * @namespaces: Data to compute which lists of sysctl entries are visible 10926e9d5164SEric W. Biederman * @path: The path to the directory the sysctl table is in. 10936e9d5164SEric W. Biederman * @table: the top-level table structure 10946e9d5164SEric W. Biederman * 10956e9d5164SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 10966e9d5164SEric W. Biederman * array. A completely 0 filled entry terminates the table. 10976e9d5164SEric W. Biederman * 10986e9d5164SEric W. Biederman * See __register_sysctl_table for more details. 10996e9d5164SEric W. Biederman */ 11006e9d5164SEric W. Biederman struct ctl_table_header *__register_sysctl_paths( 11016e9d5164SEric W. Biederman struct ctl_table_root *root, 11026e9d5164SEric W. Biederman struct nsproxy *namespaces, 11036e9d5164SEric W. Biederman const struct ctl_path *path, struct ctl_table *table) 11046e9d5164SEric W. Biederman { 1105ec6a5266SEric W. Biederman struct ctl_table *ctl_table_arg = table; 1106f728019bSEric W. Biederman int nr_subheaders = count_subheaders(table); 1107f728019bSEric W. Biederman struct ctl_table_header *header = NULL, **subheaders, **subheader; 11086e9d5164SEric W. Biederman const struct ctl_path *component; 11096e9d5164SEric W. Biederman char *new_path, *pos; 11106e9d5164SEric W. Biederman 11116e9d5164SEric W. Biederman pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); 11126e9d5164SEric W. Biederman if (!new_path) 11136e9d5164SEric W. Biederman return NULL; 11146e9d5164SEric W. Biederman 11156e9d5164SEric W. Biederman pos[0] = '\0'; 11166e9d5164SEric W. Biederman for (component = path; component->procname; component++) { 11176e9d5164SEric W. Biederman pos = append_path(new_path, pos, component->procname); 11186e9d5164SEric W. Biederman if (!pos) 11196e9d5164SEric W. Biederman goto out; 11206e9d5164SEric W. Biederman } 1121ec6a5266SEric W. Biederman while (table->procname && table->child && !table[1].procname) { 1122ec6a5266SEric W. Biederman pos = append_path(new_path, pos, table->procname); 1123ec6a5266SEric W. Biederman if (!pos) 1124ec6a5266SEric W. Biederman goto out; 1125ec6a5266SEric W. Biederman table = table->child; 1126ec6a5266SEric W. Biederman } 1127f728019bSEric W. Biederman if (nr_subheaders == 1) { 11286e9d5164SEric W. Biederman header = __register_sysctl_table(root, namespaces, new_path, table); 1129ec6a5266SEric W. Biederman if (header) 1130ec6a5266SEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1131f728019bSEric W. Biederman } else { 1132f728019bSEric W. Biederman header = kzalloc(sizeof(*header) + 1133f728019bSEric W. Biederman sizeof(*subheaders)*nr_subheaders, GFP_KERNEL); 1134f728019bSEric W. Biederman if (!header) 1135f728019bSEric W. Biederman goto out; 1136f728019bSEric W. Biederman 1137f728019bSEric W. Biederman subheaders = (struct ctl_table_header **) (header + 1); 1138f728019bSEric W. Biederman subheader = subheaders; 1139f728019bSEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1140f728019bSEric W. Biederman 1141f728019bSEric W. Biederman if (register_leaf_sysctl_tables(new_path, pos, &subheader, 1142f728019bSEric W. Biederman root, namespaces, table)) 1143f728019bSEric W. Biederman goto err_register_leaves; 1144f728019bSEric W. Biederman } 1145f728019bSEric W. Biederman 11466e9d5164SEric W. Biederman out: 11476e9d5164SEric W. Biederman kfree(new_path); 11486e9d5164SEric W. Biederman return header; 1149f728019bSEric W. Biederman 1150f728019bSEric W. Biederman err_register_leaves: 1151f728019bSEric W. Biederman while (subheader > subheaders) { 1152f728019bSEric W. Biederman struct ctl_table_header *subh = *(--subheader); 1153f728019bSEric W. Biederman struct ctl_table *table = subh->ctl_table_arg; 1154f728019bSEric W. Biederman unregister_sysctl_table(subh); 1155f728019bSEric W. Biederman kfree(table); 1156f728019bSEric W. Biederman } 1157f728019bSEric W. Biederman kfree(header); 1158f728019bSEric W. Biederman header = NULL; 1159f728019bSEric W. Biederman goto out; 11606e9d5164SEric W. Biederman } 11616e9d5164SEric W. Biederman 11621f87f0b5SEric W. Biederman /** 11631f87f0b5SEric W. Biederman * register_sysctl_table_path - register a sysctl table hierarchy 11641f87f0b5SEric W. Biederman * @path: The path to the directory the sysctl table is in. 11651f87f0b5SEric W. Biederman * @table: the top-level table structure 11661f87f0b5SEric W. Biederman * 11671f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 11681f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 11691f87f0b5SEric W. Biederman * 11701f87f0b5SEric W. Biederman * See __register_sysctl_paths for more details. 11711f87f0b5SEric W. Biederman */ 11721f87f0b5SEric W. Biederman struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, 11731f87f0b5SEric W. Biederman struct ctl_table *table) 11741f87f0b5SEric W. Biederman { 11751f87f0b5SEric W. Biederman return __register_sysctl_paths(&sysctl_table_root, current->nsproxy, 11761f87f0b5SEric W. Biederman path, table); 11771f87f0b5SEric W. Biederman } 11781f87f0b5SEric W. Biederman EXPORT_SYMBOL(register_sysctl_paths); 11791f87f0b5SEric W. Biederman 11801f87f0b5SEric W. Biederman /** 11811f87f0b5SEric W. Biederman * register_sysctl_table - register a sysctl table hierarchy 11821f87f0b5SEric W. Biederman * @table: the top-level table structure 11831f87f0b5SEric W. Biederman * 11841f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 11851f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 11861f87f0b5SEric W. Biederman * 11871f87f0b5SEric W. Biederman * See register_sysctl_paths for more details. 11881f87f0b5SEric W. Biederman */ 11891f87f0b5SEric W. Biederman struct ctl_table_header *register_sysctl_table(struct ctl_table *table) 11901f87f0b5SEric W. Biederman { 11911f87f0b5SEric W. Biederman static const struct ctl_path null_path[] = { {} }; 11921f87f0b5SEric W. Biederman 11931f87f0b5SEric W. Biederman return register_sysctl_paths(null_path, table); 11941f87f0b5SEric W. Biederman } 11951f87f0b5SEric W. Biederman EXPORT_SYMBOL(register_sysctl_table); 11961f87f0b5SEric W. Biederman 1197938aaa4fSEric W. Biederman static void drop_sysctl_table(struct ctl_table_header *header) 1198938aaa4fSEric W. Biederman { 1199938aaa4fSEric W. Biederman if (--header->nreg) 1200938aaa4fSEric W. Biederman return; 1201938aaa4fSEric W. Biederman 1202938aaa4fSEric W. Biederman start_unregistering(header); 1203938aaa4fSEric W. Biederman if (!--header->parent->count) { 1204938aaa4fSEric W. Biederman WARN_ON(1); 1205938aaa4fSEric W. Biederman kfree_rcu(header->parent, rcu); 1206938aaa4fSEric W. Biederman } 1207938aaa4fSEric W. Biederman if (!--header->count) 1208938aaa4fSEric W. Biederman kfree_rcu(header, rcu); 1209938aaa4fSEric W. Biederman } 1210938aaa4fSEric W. Biederman 12111f87f0b5SEric W. Biederman /** 12121f87f0b5SEric W. Biederman * unregister_sysctl_table - unregister a sysctl table hierarchy 12131f87f0b5SEric W. Biederman * @header: the header returned from register_sysctl_table 12141f87f0b5SEric W. Biederman * 12151f87f0b5SEric W. Biederman * Unregisters the sysctl table and all children. proc entries may not 12161f87f0b5SEric W. Biederman * actually be removed until they are no longer used by anyone. 12171f87f0b5SEric W. Biederman */ 12181f87f0b5SEric W. Biederman void unregister_sysctl_table(struct ctl_table_header * header) 12191f87f0b5SEric W. Biederman { 1220f728019bSEric W. Biederman int nr_subheaders; 12211f87f0b5SEric W. Biederman might_sleep(); 12221f87f0b5SEric W. Biederman 12231f87f0b5SEric W. Biederman if (header == NULL) 12241f87f0b5SEric W. Biederman return; 12251f87f0b5SEric W. Biederman 1226f728019bSEric W. Biederman nr_subheaders = count_subheaders(header->ctl_table_arg); 1227f728019bSEric W. Biederman if (unlikely(nr_subheaders > 1)) { 1228f728019bSEric W. Biederman struct ctl_table_header **subheaders; 1229f728019bSEric W. Biederman int i; 1230f728019bSEric W. Biederman 1231f728019bSEric W. Biederman subheaders = (struct ctl_table_header **)(header + 1); 1232f728019bSEric W. Biederman for (i = nr_subheaders -1; i >= 0; i--) { 1233f728019bSEric W. Biederman struct ctl_table_header *subh = subheaders[i]; 1234f728019bSEric W. Biederman struct ctl_table *table = subh->ctl_table_arg; 1235f728019bSEric W. Biederman unregister_sysctl_table(subh); 1236f728019bSEric W. Biederman kfree(table); 1237f728019bSEric W. Biederman } 1238f728019bSEric W. Biederman kfree(header); 1239f728019bSEric W. Biederman return; 1240f728019bSEric W. Biederman } 1241f728019bSEric W. Biederman 12421f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1243938aaa4fSEric W. Biederman drop_sysctl_table(header); 12441f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 12451f87f0b5SEric W. Biederman } 12461f87f0b5SEric W. Biederman EXPORT_SYMBOL(unregister_sysctl_table); 12471f87f0b5SEric W. Biederman 12481f87f0b5SEric W. Biederman void setup_sysctl_set(struct ctl_table_set *p, 12491f87f0b5SEric W. Biederman int (*is_seen)(struct ctl_table_set *)) 12501f87f0b5SEric W. Biederman { 12511f87f0b5SEric W. Biederman INIT_LIST_HEAD(&p->list); 12521f87f0b5SEric W. Biederman p->is_seen = is_seen; 12531f87f0b5SEric W. Biederman } 12541f87f0b5SEric W. Biederman 125597324cd8SEric W. Biederman void retire_sysctl_set(struct ctl_table_set *set) 125697324cd8SEric W. Biederman { 125797324cd8SEric W. Biederman WARN_ON(!list_empty(&set->list)); 125897324cd8SEric W. Biederman } 12591f87f0b5SEric W. Biederman 12601e0edd3fSAlexey Dobriyan int __init proc_sys_init(void) 126177b14db5SEric W. Biederman { 1262e1675231SAlexey Dobriyan struct proc_dir_entry *proc_sys_root; 1263e1675231SAlexey Dobriyan 126477b14db5SEric W. Biederman proc_sys_root = proc_mkdir("sys", NULL); 12659043476fSAl Viro proc_sys_root->proc_iops = &proc_sys_dir_operations; 12669043476fSAl Viro proc_sys_root->proc_fops = &proc_sys_dir_file_operations; 126777b14db5SEric W. Biederman proc_sys_root->nlink = 0; 1268de4e83bdSEric W. Biederman 1269de4e83bdSEric W. Biederman return sysctl_init(); 127077b14db5SEric W. Biederman } 1271