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 28a194558eSEric W. Biederman static struct ctl_table root_table[] = { 29a194558eSEric W. Biederman { 30a194558eSEric W. Biederman .procname = "", 317ec66d06SEric W. Biederman .mode = S_IFDIR|S_IRUGO|S_IXUGO, 32a194558eSEric W. Biederman }, 33a194558eSEric W. Biederman { } 34a194558eSEric W. Biederman }; 350e47c99dSEric W. Biederman static struct ctl_table_root sysctl_table_root = { 360e47c99dSEric W. Biederman .default_set.dir.header = { 371f87f0b5SEric W. Biederman {{.count = 1, 38938aaa4fSEric W. Biederman .nreg = 1, 39ac13ac6fSEric W. Biederman .ctl_table = root_table }}, 400e47c99dSEric W. Biederman .ctl_table_arg = root_table, 411f87f0b5SEric W. Biederman .root = &sysctl_table_root, 421f87f0b5SEric W. Biederman .set = &sysctl_table_root.default_set, 437ec66d06SEric W. Biederman }, 441f87f0b5SEric W. Biederman }; 451f87f0b5SEric W. Biederman 461f87f0b5SEric W. Biederman static DEFINE_SPINLOCK(sysctl_lock); 471f87f0b5SEric W. Biederman 487ec66d06SEric W. Biederman static void drop_sysctl_table(struct ctl_table_header *header); 490e47c99dSEric W. Biederman static int sysctl_follow_link(struct ctl_table_header **phead, 500e47c99dSEric W. Biederman struct ctl_table **pentry, struct nsproxy *namespaces); 510e47c99dSEric W. Biederman static int insert_links(struct ctl_table_header *head); 520e47c99dSEric W. Biederman static void put_links(struct ctl_table_header *header); 537ec66d06SEric W. Biederman 546980128fSEric W. Biederman static void sysctl_print_dir(struct ctl_dir *dir) 556980128fSEric W. Biederman { 566980128fSEric W. Biederman if (dir->header.parent) 576980128fSEric W. Biederman sysctl_print_dir(dir->header.parent); 586980128fSEric W. Biederman printk(KERN_CONT "%s/", dir->header.ctl_table[0].procname); 596980128fSEric W. Biederman } 606980128fSEric W. Biederman 61076c3eedSEric W. Biederman static int namecmp(const char *name1, int len1, const char *name2, int len2) 62076c3eedSEric W. Biederman { 63076c3eedSEric W. Biederman int minlen; 64076c3eedSEric W. Biederman int cmp; 65076c3eedSEric W. Biederman 66076c3eedSEric W. Biederman minlen = len1; 67076c3eedSEric W. Biederman if (minlen > len2) 68076c3eedSEric W. Biederman minlen = len2; 69076c3eedSEric W. Biederman 70076c3eedSEric W. Biederman cmp = memcmp(name1, name2, minlen); 71076c3eedSEric W. Biederman if (cmp == 0) 72076c3eedSEric W. Biederman cmp = len1 - len2; 73076c3eedSEric W. Biederman return cmp; 74076c3eedSEric W. Biederman } 75076c3eedSEric W. Biederman 7660f126d9SEric W. Biederman /* Called under sysctl_lock */ 77076c3eedSEric W. Biederman static struct ctl_table *find_entry(struct ctl_table_header **phead, 780e47c99dSEric W. Biederman struct ctl_dir *dir, const char *name, int namelen) 79076c3eedSEric W. Biederman { 80076c3eedSEric W. Biederman struct ctl_table_header *head; 81076c3eedSEric W. Biederman struct ctl_table *entry; 82ac13ac6fSEric W. Biederman struct rb_node *node = dir->root.rb_node; 83076c3eedSEric W. Biederman 84ac13ac6fSEric W. Biederman while (node) 85ac13ac6fSEric W. Biederman { 86ac13ac6fSEric W. Biederman struct ctl_node *ctl_node; 87ac13ac6fSEric W. Biederman const char *procname; 88ac13ac6fSEric W. Biederman int cmp; 89ac13ac6fSEric W. Biederman 90ac13ac6fSEric W. Biederman ctl_node = rb_entry(node, struct ctl_node, node); 91ac13ac6fSEric W. Biederman head = ctl_node->header; 92ac13ac6fSEric W. Biederman entry = &head->ctl_table[ctl_node - head->node]; 93ac13ac6fSEric W. Biederman procname = entry->procname; 94ac13ac6fSEric W. Biederman 95ac13ac6fSEric W. Biederman cmp = namecmp(name, namelen, procname, strlen(procname)); 96ac13ac6fSEric W. Biederman if (cmp < 0) 97ac13ac6fSEric W. Biederman node = node->rb_left; 98ac13ac6fSEric W. Biederman else if (cmp > 0) 99ac13ac6fSEric W. Biederman node = node->rb_right; 100ac13ac6fSEric W. Biederman else { 101076c3eedSEric W. Biederman *phead = head; 102076c3eedSEric W. Biederman return entry; 103076c3eedSEric W. Biederman } 104076c3eedSEric W. Biederman } 105076c3eedSEric W. Biederman return NULL; 106076c3eedSEric W. Biederman } 107076c3eedSEric W. Biederman 108ac13ac6fSEric W. Biederman static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry) 109ac13ac6fSEric W. Biederman { 110ac13ac6fSEric W. Biederman struct rb_node *node = &head->node[entry - head->ctl_table].node; 111ac13ac6fSEric W. Biederman struct rb_node **p = &head->parent->root.rb_node; 112ac13ac6fSEric W. Biederman struct rb_node *parent = NULL; 113ac13ac6fSEric W. Biederman const char *name = entry->procname; 114ac13ac6fSEric W. Biederman int namelen = strlen(name); 115ac13ac6fSEric W. Biederman 116ac13ac6fSEric W. Biederman while (*p) { 117ac13ac6fSEric W. Biederman struct ctl_table_header *parent_head; 118ac13ac6fSEric W. Biederman struct ctl_table *parent_entry; 119ac13ac6fSEric W. Biederman struct ctl_node *parent_node; 120ac13ac6fSEric W. Biederman const char *parent_name; 121ac13ac6fSEric W. Biederman int cmp; 122ac13ac6fSEric W. Biederman 123ac13ac6fSEric W. Biederman parent = *p; 124ac13ac6fSEric W. Biederman parent_node = rb_entry(parent, struct ctl_node, node); 125ac13ac6fSEric W. Biederman parent_head = parent_node->header; 126ac13ac6fSEric W. Biederman parent_entry = &parent_head->ctl_table[parent_node - parent_head->node]; 127ac13ac6fSEric W. Biederman parent_name = parent_entry->procname; 128ac13ac6fSEric W. Biederman 129ac13ac6fSEric W. Biederman cmp = namecmp(name, namelen, parent_name, strlen(parent_name)); 130ac13ac6fSEric W. Biederman if (cmp < 0) 131ac13ac6fSEric W. Biederman p = &(*p)->rb_left; 132ac13ac6fSEric W. Biederman else if (cmp > 0) 133ac13ac6fSEric W. Biederman p = &(*p)->rb_right; 134ac13ac6fSEric W. Biederman else { 135ac13ac6fSEric W. Biederman printk(KERN_ERR "sysctl duplicate entry: "); 136ac13ac6fSEric W. Biederman sysctl_print_dir(head->parent); 137ac13ac6fSEric W. Biederman printk(KERN_CONT "/%s\n", entry->procname); 138ac13ac6fSEric W. Biederman return -EEXIST; 139ac13ac6fSEric W. Biederman } 140ac13ac6fSEric W. Biederman } 141ac13ac6fSEric W. Biederman 142ac13ac6fSEric W. Biederman rb_link_node(node, parent, p); 143ac13ac6fSEric W. Biederman return 0; 144ac13ac6fSEric W. Biederman } 145ac13ac6fSEric W. Biederman 146ac13ac6fSEric W. Biederman static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry) 147ac13ac6fSEric W. Biederman { 148ac13ac6fSEric W. Biederman struct rb_node *node = &head->node[entry - head->ctl_table].node; 149ac13ac6fSEric W. Biederman 150ac13ac6fSEric W. Biederman rb_erase(node, &head->parent->root); 151ac13ac6fSEric W. Biederman } 152ac13ac6fSEric W. Biederman 153e0d04529SEric W. Biederman static void init_header(struct ctl_table_header *head, 154e0d04529SEric W. Biederman struct ctl_table_root *root, struct ctl_table_set *set, 155ac13ac6fSEric W. Biederman struct ctl_node *node, struct ctl_table *table) 156e0d04529SEric W. Biederman { 1577ec66d06SEric W. Biederman head->ctl_table = table; 158e0d04529SEric W. Biederman head->ctl_table_arg = table; 159e0d04529SEric W. Biederman head->used = 0; 160e0d04529SEric W. Biederman head->count = 1; 161e0d04529SEric W. Biederman head->nreg = 1; 162e0d04529SEric W. Biederman head->unregistering = NULL; 163e0d04529SEric W. Biederman head->root = root; 164e0d04529SEric W. Biederman head->set = set; 165e0d04529SEric W. Biederman head->parent = NULL; 166ac13ac6fSEric W. Biederman head->node = node; 167ac13ac6fSEric W. Biederman if (node) { 168ac13ac6fSEric W. Biederman struct ctl_table *entry; 169ac13ac6fSEric W. Biederman for (entry = table; entry->procname; entry++, node++) { 170ac13ac6fSEric W. Biederman rb_init_node(&node->node); 171ac13ac6fSEric W. Biederman node->header = head; 172ac13ac6fSEric W. Biederman } 173ac13ac6fSEric W. Biederman } 174e0d04529SEric W. Biederman } 175e0d04529SEric W. Biederman 1768425d6aaSEric W. Biederman static void erase_header(struct ctl_table_header *head) 1778425d6aaSEric W. Biederman { 178ac13ac6fSEric W. Biederman struct ctl_table *entry; 179ac13ac6fSEric W. Biederman for (entry = head->ctl_table; entry->procname; entry++) 180ac13ac6fSEric W. Biederman erase_entry(head, entry); 1818425d6aaSEric W. Biederman } 1828425d6aaSEric W. Biederman 1830e47c99dSEric W. Biederman static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) 1848425d6aaSEric W. Biederman { 185ac13ac6fSEric W. Biederman struct ctl_table *entry; 1860e47c99dSEric W. Biederman int err; 1870e47c99dSEric W. Biederman 1880e47c99dSEric W. Biederman dir->header.nreg++; 1897ec66d06SEric W. Biederman header->parent = dir; 1900e47c99dSEric W. Biederman err = insert_links(header); 1910e47c99dSEric W. Biederman if (err) 1920e47c99dSEric W. Biederman goto fail_links; 193ac13ac6fSEric W. Biederman for (entry = header->ctl_table; entry->procname; entry++) { 194ac13ac6fSEric W. Biederman err = insert_entry(header, entry); 195ac13ac6fSEric W. Biederman if (err) 196ac13ac6fSEric W. Biederman goto fail; 197ac13ac6fSEric W. Biederman } 1980e47c99dSEric W. Biederman return 0; 199ac13ac6fSEric W. Biederman fail: 200ac13ac6fSEric W. Biederman erase_header(header); 201ac13ac6fSEric W. Biederman put_links(header); 2020e47c99dSEric W. Biederman fail_links: 2030e47c99dSEric W. Biederman header->parent = NULL; 2040e47c99dSEric W. Biederman drop_sysctl_table(&dir->header); 2050e47c99dSEric W. Biederman return err; 2068425d6aaSEric W. Biederman } 2078425d6aaSEric W. Biederman 2081f87f0b5SEric W. Biederman /* called under sysctl_lock */ 2091f87f0b5SEric W. Biederman static int use_table(struct ctl_table_header *p) 2101f87f0b5SEric W. Biederman { 2111f87f0b5SEric W. Biederman if (unlikely(p->unregistering)) 2121f87f0b5SEric W. Biederman return 0; 2131f87f0b5SEric W. Biederman p->used++; 2141f87f0b5SEric W. Biederman return 1; 2151f87f0b5SEric W. Biederman } 2161f87f0b5SEric W. Biederman 2171f87f0b5SEric W. Biederman /* called under sysctl_lock */ 2181f87f0b5SEric W. Biederman static void unuse_table(struct ctl_table_header *p) 2191f87f0b5SEric W. Biederman { 2201f87f0b5SEric W. Biederman if (!--p->used) 2211f87f0b5SEric W. Biederman if (unlikely(p->unregistering)) 2221f87f0b5SEric W. Biederman complete(p->unregistering); 2231f87f0b5SEric W. Biederman } 2241f87f0b5SEric W. Biederman 2251f87f0b5SEric W. Biederman /* called under sysctl_lock, will reacquire if has to wait */ 2261f87f0b5SEric W. Biederman static void start_unregistering(struct ctl_table_header *p) 2271f87f0b5SEric W. Biederman { 2281f87f0b5SEric W. Biederman /* 2291f87f0b5SEric W. Biederman * if p->used is 0, nobody will ever touch that entry again; 2301f87f0b5SEric W. Biederman * we'll eliminate all paths to it before dropping sysctl_lock 2311f87f0b5SEric W. Biederman */ 2321f87f0b5SEric W. Biederman if (unlikely(p->used)) { 2331f87f0b5SEric W. Biederman struct completion wait; 2341f87f0b5SEric W. Biederman init_completion(&wait); 2351f87f0b5SEric W. Biederman p->unregistering = &wait; 2361f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2371f87f0b5SEric W. Biederman wait_for_completion(&wait); 2381f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 2391f87f0b5SEric W. Biederman } else { 2401f87f0b5SEric W. Biederman /* anything non-NULL; we'll never dereference it */ 2411f87f0b5SEric W. Biederman p->unregistering = ERR_PTR(-EINVAL); 2421f87f0b5SEric W. Biederman } 2431f87f0b5SEric W. Biederman /* 2441f87f0b5SEric W. Biederman * do not remove from the list until nobody holds it; walking the 2451f87f0b5SEric W. Biederman * list in do_sysctl() relies on that. 2461f87f0b5SEric W. Biederman */ 2478425d6aaSEric W. Biederman erase_header(p); 2481f87f0b5SEric W. Biederman } 2491f87f0b5SEric W. Biederman 2501f87f0b5SEric W. Biederman static void sysctl_head_get(struct ctl_table_header *head) 2511f87f0b5SEric W. Biederman { 2521f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 2531f87f0b5SEric W. Biederman head->count++; 2541f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2551f87f0b5SEric W. Biederman } 2561f87f0b5SEric W. Biederman 2571f87f0b5SEric W. Biederman void sysctl_head_put(struct ctl_table_header *head) 2581f87f0b5SEric W. Biederman { 2591f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 2601f87f0b5SEric W. Biederman if (!--head->count) 2611f87f0b5SEric W. Biederman kfree_rcu(head, rcu); 2621f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2631f87f0b5SEric W. Biederman } 2641f87f0b5SEric W. Biederman 2651f87f0b5SEric W. Biederman static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) 2661f87f0b5SEric W. Biederman { 2671f87f0b5SEric W. Biederman if (!head) 2681f87f0b5SEric W. Biederman BUG(); 2691f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 2701f87f0b5SEric W. Biederman if (!use_table(head)) 2711f87f0b5SEric W. Biederman head = ERR_PTR(-ENOENT); 2721f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2731f87f0b5SEric W. Biederman return head; 2741f87f0b5SEric W. Biederman } 2751f87f0b5SEric W. Biederman 2761f87f0b5SEric W. Biederman static void sysctl_head_finish(struct ctl_table_header *head) 2771f87f0b5SEric W. Biederman { 2781f87f0b5SEric W. Biederman if (!head) 2791f87f0b5SEric W. Biederman return; 2801f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 2811f87f0b5SEric W. Biederman unuse_table(head); 2821f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2831f87f0b5SEric W. Biederman } 2841f87f0b5SEric W. Biederman 2851f87f0b5SEric W. Biederman static struct ctl_table_set * 2861f87f0b5SEric W. Biederman lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces) 2871f87f0b5SEric W. Biederman { 2881f87f0b5SEric W. Biederman struct ctl_table_set *set = &root->default_set; 2891f87f0b5SEric W. Biederman if (root->lookup) 2901f87f0b5SEric W. Biederman set = root->lookup(root, namespaces); 2911f87f0b5SEric W. Biederman return set; 2921f87f0b5SEric W. Biederman } 2931f87f0b5SEric W. Biederman 294076c3eedSEric W. Biederman static struct ctl_table *lookup_entry(struct ctl_table_header **phead, 2957ec66d06SEric W. Biederman struct ctl_dir *dir, 296076c3eedSEric W. Biederman const char *name, int namelen) 297076c3eedSEric W. Biederman { 298076c3eedSEric W. Biederman struct ctl_table_header *head; 299076c3eedSEric W. Biederman struct ctl_table *entry; 300076c3eedSEric W. Biederman 301076c3eedSEric W. Biederman spin_lock(&sysctl_lock); 3020e47c99dSEric W. Biederman entry = find_entry(&head, dir, name, namelen); 303076c3eedSEric W. Biederman if (entry && use_table(head)) 304076c3eedSEric W. Biederman *phead = head; 305076c3eedSEric W. Biederman else 306076c3eedSEric W. Biederman entry = NULL; 307076c3eedSEric W. Biederman spin_unlock(&sysctl_lock); 308076c3eedSEric W. Biederman return entry; 309076c3eedSEric W. Biederman } 310076c3eedSEric W. Biederman 311ac13ac6fSEric W. Biederman static struct ctl_node *first_usable_entry(struct rb_node *node) 3121f87f0b5SEric W. Biederman { 313ac13ac6fSEric W. Biederman struct ctl_node *ctl_node; 3141f87f0b5SEric W. Biederman 315ac13ac6fSEric W. Biederman for (;node; node = rb_next(node)) { 316ac13ac6fSEric W. Biederman ctl_node = rb_entry(node, struct ctl_node, node); 317ac13ac6fSEric W. Biederman if (use_table(ctl_node->header)) 318ac13ac6fSEric W. Biederman return ctl_node; 3191f87f0b5SEric W. Biederman } 3201f87f0b5SEric W. Biederman return NULL; 3211f87f0b5SEric W. Biederman } 3221f87f0b5SEric W. Biederman 3237ec66d06SEric W. Biederman static void first_entry(struct ctl_dir *dir, 3246a75ce16SEric W. Biederman struct ctl_table_header **phead, struct ctl_table **pentry) 3251f87f0b5SEric W. Biederman { 326ac13ac6fSEric W. Biederman struct ctl_table_header *head = NULL; 3277ec66d06SEric W. Biederman struct ctl_table *entry = NULL; 328ac13ac6fSEric W. Biederman struct ctl_node *ctl_node; 3296a75ce16SEric W. Biederman 3306a75ce16SEric W. Biederman spin_lock(&sysctl_lock); 331ac13ac6fSEric W. Biederman ctl_node = first_usable_entry(rb_first(&dir->root)); 3326a75ce16SEric W. Biederman spin_unlock(&sysctl_lock); 333ac13ac6fSEric W. Biederman if (ctl_node) { 334ac13ac6fSEric W. Biederman head = ctl_node->header; 335ac13ac6fSEric W. Biederman entry = &head->ctl_table[ctl_node - head->node]; 336ac13ac6fSEric W. Biederman } 3376a75ce16SEric W. Biederman *phead = head; 3386a75ce16SEric W. Biederman *pentry = entry; 3396a75ce16SEric W. Biederman } 3406a75ce16SEric W. Biederman 3417ec66d06SEric W. Biederman static void next_entry(struct ctl_table_header **phead, struct ctl_table **pentry) 3426a75ce16SEric W. Biederman { 3436a75ce16SEric W. Biederman struct ctl_table_header *head = *phead; 3446a75ce16SEric W. Biederman struct ctl_table *entry = *pentry; 345ac13ac6fSEric W. Biederman struct ctl_node *ctl_node = &head->node[entry - head->ctl_table]; 3466a75ce16SEric W. Biederman 3476a75ce16SEric W. Biederman spin_lock(&sysctl_lock); 3486a75ce16SEric W. Biederman unuse_table(head); 349ac13ac6fSEric W. Biederman 350ac13ac6fSEric W. Biederman ctl_node = first_usable_entry(rb_next(&ctl_node->node)); 3516a75ce16SEric W. Biederman spin_unlock(&sysctl_lock); 352ac13ac6fSEric W. Biederman head = NULL; 353ac13ac6fSEric W. Biederman if (ctl_node) { 354ac13ac6fSEric W. Biederman head = ctl_node->header; 355ac13ac6fSEric W. Biederman entry = &head->ctl_table[ctl_node - head->node]; 3566a75ce16SEric W. Biederman } 3576a75ce16SEric W. Biederman *phead = head; 3586a75ce16SEric W. Biederman *pentry = entry; 3591f87f0b5SEric W. Biederman } 3601f87f0b5SEric W. Biederman 3611f87f0b5SEric W. Biederman void register_sysctl_root(struct ctl_table_root *root) 3621f87f0b5SEric W. Biederman { 3631f87f0b5SEric W. Biederman } 3641f87f0b5SEric W. Biederman 3651f87f0b5SEric W. Biederman /* 3661f87f0b5SEric W. Biederman * sysctl_perm does NOT grant the superuser all rights automatically, because 3671f87f0b5SEric W. Biederman * some sysctl variables are readonly even to root. 3681f87f0b5SEric W. Biederman */ 3691f87f0b5SEric W. Biederman 3701f87f0b5SEric W. Biederman static int test_perm(int mode, int op) 3711f87f0b5SEric W. Biederman { 3721f87f0b5SEric W. Biederman if (!current_euid()) 3731f87f0b5SEric W. Biederman mode >>= 6; 3741f87f0b5SEric W. Biederman else if (in_egroup_p(0)) 3751f87f0b5SEric W. Biederman mode >>= 3; 3761f87f0b5SEric W. Biederman if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) 3771f87f0b5SEric W. Biederman return 0; 3781f87f0b5SEric W. Biederman return -EACCES; 3791f87f0b5SEric W. Biederman } 3801f87f0b5SEric W. Biederman 3811f87f0b5SEric W. Biederman static int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op) 3821f87f0b5SEric W. Biederman { 3831f87f0b5SEric W. Biederman int mode; 3841f87f0b5SEric W. Biederman 3851f87f0b5SEric W. Biederman if (root->permissions) 3861f87f0b5SEric W. Biederman mode = root->permissions(root, current->nsproxy, table); 3871f87f0b5SEric W. Biederman else 3881f87f0b5SEric W. Biederman mode = table->mode; 3891f87f0b5SEric W. Biederman 3901f87f0b5SEric W. Biederman return test_perm(mode, op); 3911f87f0b5SEric W. Biederman } 3921f87f0b5SEric W. Biederman 3939043476fSAl Viro static struct inode *proc_sys_make_inode(struct super_block *sb, 3949043476fSAl Viro struct ctl_table_header *head, struct ctl_table *table) 39577b14db5SEric W. Biederman { 39677b14db5SEric W. Biederman struct inode *inode; 3979043476fSAl Viro struct proc_inode *ei; 39877b14db5SEric W. Biederman 3999043476fSAl Viro inode = new_inode(sb); 40077b14db5SEric W. Biederman if (!inode) 40177b14db5SEric W. Biederman goto out; 40277b14db5SEric W. Biederman 40385fe4025SChristoph Hellwig inode->i_ino = get_next_ino(); 40485fe4025SChristoph Hellwig 4059043476fSAl Viro sysctl_head_get(head); 40677b14db5SEric W. Biederman ei = PROC_I(inode); 4079043476fSAl Viro ei->sysctl = head; 4089043476fSAl Viro ei->sysctl_entry = table; 4099043476fSAl Viro 41077b14db5SEric W. Biederman inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 4119043476fSAl Viro inode->i_mode = table->mode; 4127ec66d06SEric W. Biederman if (!S_ISDIR(table->mode)) { 4139043476fSAl Viro inode->i_mode |= S_IFREG; 41477b14db5SEric W. Biederman inode->i_op = &proc_sys_inode_operations; 41577b14db5SEric W. Biederman inode->i_fop = &proc_sys_file_operations; 4169043476fSAl Viro } else { 4179043476fSAl Viro inode->i_mode |= S_IFDIR; 4189043476fSAl Viro inode->i_op = &proc_sys_dir_operations; 4199043476fSAl Viro inode->i_fop = &proc_sys_dir_file_operations; 4209043476fSAl Viro } 42177b14db5SEric W. Biederman out: 42277b14db5SEric W. Biederman return inode; 42377b14db5SEric W. Biederman } 42477b14db5SEric W. Biederman 42581324364SAdrian Bunk static struct ctl_table_header *grab_header(struct inode *inode) 42677b14db5SEric W. Biederman { 4273cc3e046SEric W. Biederman struct ctl_table_header *head = PROC_I(inode)->sysctl; 4283cc3e046SEric W. Biederman if (!head) 4290e47c99dSEric W. Biederman head = &sysctl_table_root.default_set.dir.header; 4303cc3e046SEric W. Biederman return sysctl_head_grab(head); 43177b14db5SEric W. Biederman } 43277b14db5SEric W. Biederman 43377b14db5SEric W. Biederman static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, 43477b14db5SEric W. Biederman struct nameidata *nd) 43577b14db5SEric W. Biederman { 4369043476fSAl Viro struct ctl_table_header *head = grab_header(dir); 4379043476fSAl Viro struct ctl_table_header *h = NULL; 4389043476fSAl Viro struct qstr *name = &dentry->d_name; 4399043476fSAl Viro struct ctl_table *p; 44077b14db5SEric W. Biederman struct inode *inode; 4419043476fSAl Viro struct dentry *err = ERR_PTR(-ENOENT); 4427ec66d06SEric W. Biederman struct ctl_dir *ctl_dir; 4430e47c99dSEric W. Biederman int ret; 44477b14db5SEric W. Biederman 4459043476fSAl Viro if (IS_ERR(head)) 4469043476fSAl Viro return ERR_CAST(head); 4479043476fSAl Viro 4487ec66d06SEric W. Biederman ctl_dir = container_of(head, struct ctl_dir, header); 4499043476fSAl Viro 4507ec66d06SEric W. Biederman p = lookup_entry(&h, ctl_dir, name->name, name->len); 4519043476fSAl Viro if (!p) 45277b14db5SEric W. Biederman goto out; 45377b14db5SEric W. Biederman 4540e47c99dSEric W. Biederman ret = sysctl_follow_link(&h, &p, current->nsproxy); 4550e47c99dSEric W. Biederman err = ERR_PTR(ret); 4560e47c99dSEric W. Biederman if (ret) 4570e47c99dSEric W. Biederman goto out; 4580e47c99dSEric W. Biederman 45977b14db5SEric W. Biederman err = ERR_PTR(-ENOMEM); 4609043476fSAl Viro inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); 4619043476fSAl Viro if (h) 4629043476fSAl Viro sysctl_head_finish(h); 4639043476fSAl Viro 46477b14db5SEric W. Biederman if (!inode) 46577b14db5SEric W. Biederman goto out; 46677b14db5SEric W. Biederman 46777b14db5SEric W. Biederman err = NULL; 468fb045adbSNick Piggin d_set_d_op(dentry, &proc_sys_dentry_operations); 46977b14db5SEric W. Biederman d_add(dentry, inode); 47077b14db5SEric W. Biederman 47177b14db5SEric W. Biederman out: 47277b14db5SEric W. Biederman sysctl_head_finish(head); 47377b14db5SEric W. Biederman return err; 47477b14db5SEric W. Biederman } 47577b14db5SEric W. Biederman 4767708bfb1SPavel Emelyanov static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf, 4777708bfb1SPavel Emelyanov size_t count, loff_t *ppos, int write) 47877b14db5SEric W. Biederman { 4799043476fSAl Viro struct inode *inode = filp->f_path.dentry->d_inode; 4809043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 4819043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 4822a2da53bSDavid Howells ssize_t error; 4832a2da53bSDavid Howells size_t res; 48477b14db5SEric W. Biederman 4859043476fSAl Viro if (IS_ERR(head)) 4869043476fSAl Viro return PTR_ERR(head); 48777b14db5SEric W. Biederman 48877b14db5SEric W. Biederman /* 48977b14db5SEric W. Biederman * At this point we know that the sysctl was not unregistered 49077b14db5SEric W. Biederman * and won't be until we finish. 49177b14db5SEric W. Biederman */ 49277b14db5SEric W. Biederman error = -EPERM; 493d7321cd6SPavel Emelyanov if (sysctl_perm(head->root, table, write ? MAY_WRITE : MAY_READ)) 49477b14db5SEric W. Biederman goto out; 49577b14db5SEric W. Biederman 4969043476fSAl Viro /* if that can happen at all, it should be -EINVAL, not -EISDIR */ 4979043476fSAl Viro error = -EINVAL; 4989043476fSAl Viro if (!table->proc_handler) 4999043476fSAl Viro goto out; 5009043476fSAl Viro 50177b14db5SEric W. Biederman /* careful: calling conventions are nasty here */ 50277b14db5SEric W. Biederman res = count; 5038d65af78SAlexey Dobriyan error = table->proc_handler(table, write, buf, &res, ppos); 50477b14db5SEric W. Biederman if (!error) 50577b14db5SEric W. Biederman error = res; 50677b14db5SEric W. Biederman out: 50777b14db5SEric W. Biederman sysctl_head_finish(head); 50877b14db5SEric W. Biederman 50977b14db5SEric W. Biederman return error; 51077b14db5SEric W. Biederman } 51177b14db5SEric W. Biederman 5127708bfb1SPavel Emelyanov static ssize_t proc_sys_read(struct file *filp, char __user *buf, 5137708bfb1SPavel Emelyanov size_t count, loff_t *ppos) 5147708bfb1SPavel Emelyanov { 5157708bfb1SPavel Emelyanov return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0); 5167708bfb1SPavel Emelyanov } 5177708bfb1SPavel Emelyanov 51877b14db5SEric W. Biederman static ssize_t proc_sys_write(struct file *filp, const char __user *buf, 51977b14db5SEric W. Biederman size_t count, loff_t *ppos) 52077b14db5SEric W. Biederman { 5217708bfb1SPavel Emelyanov return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1); 52277b14db5SEric W. Biederman } 52377b14db5SEric W. Biederman 524f1ecf068SLucas De Marchi static int proc_sys_open(struct inode *inode, struct file *filp) 525f1ecf068SLucas De Marchi { 526f1ecf068SLucas De Marchi struct ctl_table *table = PROC_I(inode)->sysctl_entry; 527f1ecf068SLucas De Marchi 528f1ecf068SLucas De Marchi if (table->poll) 529f1ecf068SLucas De Marchi filp->private_data = proc_sys_poll_event(table->poll); 530f1ecf068SLucas De Marchi 531f1ecf068SLucas De Marchi return 0; 532f1ecf068SLucas De Marchi } 533f1ecf068SLucas De Marchi 534f1ecf068SLucas De Marchi static unsigned int proc_sys_poll(struct file *filp, poll_table *wait) 535f1ecf068SLucas De Marchi { 536f1ecf068SLucas De Marchi struct inode *inode = filp->f_path.dentry->d_inode; 537f1ecf068SLucas De Marchi struct ctl_table *table = PROC_I(inode)->sysctl_entry; 538f1ecf068SLucas De Marchi unsigned long event = (unsigned long)filp->private_data; 539f1ecf068SLucas De Marchi unsigned int ret = DEFAULT_POLLMASK; 540f1ecf068SLucas De Marchi 541f1ecf068SLucas De Marchi if (!table->proc_handler) 542f1ecf068SLucas De Marchi goto out; 543f1ecf068SLucas De Marchi 544f1ecf068SLucas De Marchi if (!table->poll) 545f1ecf068SLucas De Marchi goto out; 546f1ecf068SLucas De Marchi 547f1ecf068SLucas De Marchi poll_wait(filp, &table->poll->wait, wait); 548f1ecf068SLucas De Marchi 549f1ecf068SLucas De Marchi if (event != atomic_read(&table->poll->event)) { 550f1ecf068SLucas De Marchi filp->private_data = proc_sys_poll_event(table->poll); 551f1ecf068SLucas De Marchi ret = POLLIN | POLLRDNORM | POLLERR | POLLPRI; 552f1ecf068SLucas De Marchi } 553f1ecf068SLucas De Marchi 554f1ecf068SLucas De Marchi out: 555f1ecf068SLucas De Marchi return ret; 556f1ecf068SLucas De Marchi } 55777b14db5SEric W. Biederman 55877b14db5SEric W. Biederman static int proc_sys_fill_cache(struct file *filp, void *dirent, 5599043476fSAl Viro filldir_t filldir, 5609043476fSAl Viro struct ctl_table_header *head, 5619043476fSAl Viro struct ctl_table *table) 56277b14db5SEric W. Biederman { 56377b14db5SEric W. Biederman struct dentry *child, *dir = filp->f_path.dentry; 56477b14db5SEric W. Biederman struct inode *inode; 56577b14db5SEric W. Biederman struct qstr qname; 56677b14db5SEric W. Biederman ino_t ino = 0; 56777b14db5SEric W. Biederman unsigned type = DT_UNKNOWN; 56877b14db5SEric W. Biederman 56977b14db5SEric W. Biederman qname.name = table->procname; 57077b14db5SEric W. Biederman qname.len = strlen(table->procname); 57177b14db5SEric W. Biederman qname.hash = full_name_hash(qname.name, qname.len); 57277b14db5SEric W. Biederman 57377b14db5SEric W. Biederman child = d_lookup(dir, &qname); 57477b14db5SEric W. Biederman if (!child) { 5759043476fSAl Viro child = d_alloc(dir, &qname); 5769043476fSAl Viro if (child) { 5779043476fSAl Viro inode = proc_sys_make_inode(dir->d_sb, head, table); 5789043476fSAl Viro if (!inode) { 5799043476fSAl Viro dput(child); 5809043476fSAl Viro return -ENOMEM; 5819043476fSAl Viro } else { 582fb045adbSNick Piggin d_set_d_op(child, &proc_sys_dentry_operations); 5839043476fSAl Viro d_add(child, inode); 58477b14db5SEric W. Biederman } 5859043476fSAl Viro } else { 5869043476fSAl Viro return -ENOMEM; 58777b14db5SEric W. Biederman } 58877b14db5SEric W. Biederman } 58977b14db5SEric W. Biederman inode = child->d_inode; 59077b14db5SEric W. Biederman ino = inode->i_ino; 59177b14db5SEric W. Biederman type = inode->i_mode >> 12; 59277b14db5SEric W. Biederman dput(child); 5939043476fSAl Viro return !!filldir(dirent, qname.name, qname.len, filp->f_pos, ino, type); 5949043476fSAl Viro } 5959043476fSAl Viro 5960e47c99dSEric W. Biederman static int proc_sys_link_fill_cache(struct file *filp, void *dirent, 5970e47c99dSEric W. Biederman filldir_t filldir, 5980e47c99dSEric W. Biederman struct ctl_table_header *head, 5990e47c99dSEric W. Biederman struct ctl_table *table) 6000e47c99dSEric W. Biederman { 6010e47c99dSEric W. Biederman int err, ret = 0; 6020e47c99dSEric W. Biederman head = sysctl_head_grab(head); 6030e47c99dSEric W. Biederman 6040e47c99dSEric W. Biederman /* It is not an error if we can not follow the link ignore it */ 6050e47c99dSEric W. Biederman err = sysctl_follow_link(&head, &table, current->nsproxy); 6060e47c99dSEric W. Biederman if (err) 6070e47c99dSEric W. Biederman goto out; 6080e47c99dSEric W. Biederman 6090e47c99dSEric W. Biederman ret = proc_sys_fill_cache(filp, dirent, filldir, head, table); 6100e47c99dSEric W. Biederman out: 6110e47c99dSEric W. Biederman sysctl_head_finish(head); 6120e47c99dSEric W. Biederman return ret; 6130e47c99dSEric W. Biederman } 6140e47c99dSEric W. Biederman 6159043476fSAl Viro static int scan(struct ctl_table_header *head, ctl_table *table, 6169043476fSAl Viro unsigned long *pos, struct file *file, 6179043476fSAl Viro void *dirent, filldir_t filldir) 6189043476fSAl Viro { 6199043476fSAl Viro int res; 6209043476fSAl Viro 6216a75ce16SEric W. Biederman if ((*pos)++ < file->f_pos) 6226a75ce16SEric W. Biederman return 0; 6239043476fSAl Viro 6240e47c99dSEric W. Biederman if (unlikely(S_ISLNK(table->mode))) 6250e47c99dSEric W. Biederman res = proc_sys_link_fill_cache(file, dirent, filldir, head, table); 6260e47c99dSEric W. Biederman else 6279043476fSAl Viro res = proc_sys_fill_cache(file, dirent, filldir, head, table); 6289043476fSAl Viro 6296a75ce16SEric W. Biederman if (res == 0) 6306a75ce16SEric W. Biederman file->f_pos = *pos; 6316a75ce16SEric W. Biederman 6326a75ce16SEric W. Biederman return res; 63377b14db5SEric W. Biederman } 63477b14db5SEric W. Biederman 63577b14db5SEric W. Biederman static int proc_sys_readdir(struct file *filp, void *dirent, filldir_t filldir) 63677b14db5SEric W. Biederman { 6379043476fSAl Viro struct dentry *dentry = filp->f_path.dentry; 63877b14db5SEric W. Biederman struct inode *inode = dentry->d_inode; 6399043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 6409043476fSAl Viro struct ctl_table_header *h = NULL; 6416a75ce16SEric W. Biederman struct ctl_table *entry; 6427ec66d06SEric W. Biederman struct ctl_dir *ctl_dir; 64377b14db5SEric W. Biederman unsigned long pos; 6449043476fSAl Viro int ret = -EINVAL; 64577b14db5SEric W. Biederman 6469043476fSAl Viro if (IS_ERR(head)) 6479043476fSAl Viro return PTR_ERR(head); 6489043476fSAl Viro 6497ec66d06SEric W. Biederman ctl_dir = container_of(head, struct ctl_dir, header); 65077b14db5SEric W. Biederman 65177b14db5SEric W. Biederman ret = 0; 65277b14db5SEric W. Biederman /* Avoid a switch here: arm builds fail with missing __cmpdi2 */ 65377b14db5SEric W. Biederman if (filp->f_pos == 0) { 65477b14db5SEric W. Biederman if (filldir(dirent, ".", 1, filp->f_pos, 65577b14db5SEric W. Biederman inode->i_ino, DT_DIR) < 0) 65677b14db5SEric W. Biederman goto out; 65777b14db5SEric W. Biederman filp->f_pos++; 65877b14db5SEric W. Biederman } 65977b14db5SEric W. Biederman if (filp->f_pos == 1) { 66077b14db5SEric W. Biederman if (filldir(dirent, "..", 2, filp->f_pos, 66177b14db5SEric W. Biederman parent_ino(dentry), DT_DIR) < 0) 66277b14db5SEric W. Biederman goto out; 66377b14db5SEric W. Biederman filp->f_pos++; 66477b14db5SEric W. Biederman } 66577b14db5SEric W. Biederman pos = 2; 66677b14db5SEric W. Biederman 6677ec66d06SEric W. Biederman for (first_entry(ctl_dir, &h, &entry); h; next_entry(&h, &entry)) { 6686a75ce16SEric W. Biederman ret = scan(h, entry, &pos, filp, dirent, filldir); 6699043476fSAl Viro if (ret) { 6709043476fSAl Viro sysctl_head_finish(h); 6719043476fSAl Viro break; 67277b14db5SEric W. Biederman } 67377b14db5SEric W. Biederman } 67477b14db5SEric W. Biederman ret = 1; 67577b14db5SEric W. Biederman out: 67677b14db5SEric W. Biederman sysctl_head_finish(head); 67777b14db5SEric W. Biederman return ret; 67877b14db5SEric W. Biederman } 67977b14db5SEric W. Biederman 68010556cb2SAl Viro static int proc_sys_permission(struct inode *inode, int mask) 68177b14db5SEric W. Biederman { 68277b14db5SEric W. Biederman /* 68377b14db5SEric W. Biederman * sysctl entries that are not writeable, 68477b14db5SEric W. Biederman * are _NOT_ writeable, capabilities or not. 68577b14db5SEric W. Biederman */ 686f696a365SMiklos Szeredi struct ctl_table_header *head; 687f696a365SMiklos Szeredi struct ctl_table *table; 68877b14db5SEric W. Biederman int error; 68977b14db5SEric W. Biederman 690f696a365SMiklos Szeredi /* Executable files are not allowed under /proc/sys/ */ 691f696a365SMiklos Szeredi if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) 692f696a365SMiklos Szeredi return -EACCES; 693f696a365SMiklos Szeredi 694f696a365SMiklos Szeredi head = grab_header(inode); 6959043476fSAl Viro if (IS_ERR(head)) 6969043476fSAl Viro return PTR_ERR(head); 69777b14db5SEric W. Biederman 698f696a365SMiklos Szeredi table = PROC_I(inode)->sysctl_entry; 6999043476fSAl Viro if (!table) /* global root - r-xr-xr-x */ 7009043476fSAl Viro error = mask & MAY_WRITE ? -EACCES : 0; 7019043476fSAl Viro else /* Use the permissions on the sysctl table entry */ 7021fc0f78cSAl Viro error = sysctl_perm(head->root, table, mask & ~MAY_NOT_BLOCK); 7039043476fSAl Viro 70477b14db5SEric W. Biederman sysctl_head_finish(head); 70577b14db5SEric W. Biederman return error; 70677b14db5SEric W. Biederman } 70777b14db5SEric W. Biederman 70877b14db5SEric W. Biederman static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr) 70977b14db5SEric W. Biederman { 71077b14db5SEric W. Biederman struct inode *inode = dentry->d_inode; 71177b14db5SEric W. Biederman int error; 71277b14db5SEric W. Biederman 71377b14db5SEric W. Biederman if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) 71477b14db5SEric W. Biederman return -EPERM; 71577b14db5SEric W. Biederman 71677b14db5SEric W. Biederman error = inode_change_ok(inode, attr); 7171025774cSChristoph Hellwig if (error) 71877b14db5SEric W. Biederman return error; 7191025774cSChristoph Hellwig 7201025774cSChristoph Hellwig if ((attr->ia_valid & ATTR_SIZE) && 7211025774cSChristoph Hellwig attr->ia_size != i_size_read(inode)) { 7221025774cSChristoph Hellwig error = vmtruncate(inode, attr->ia_size); 7231025774cSChristoph Hellwig if (error) 7241025774cSChristoph Hellwig return error; 7251025774cSChristoph Hellwig } 7261025774cSChristoph Hellwig 7271025774cSChristoph Hellwig setattr_copy(inode, attr); 7281025774cSChristoph Hellwig mark_inode_dirty(inode); 7291025774cSChristoph Hellwig return 0; 73077b14db5SEric W. Biederman } 73177b14db5SEric W. Biederman 7329043476fSAl Viro static int proc_sys_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 7339043476fSAl Viro { 7349043476fSAl Viro struct inode *inode = dentry->d_inode; 7359043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 7369043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 7379043476fSAl Viro 7389043476fSAl Viro if (IS_ERR(head)) 7399043476fSAl Viro return PTR_ERR(head); 7409043476fSAl Viro 7419043476fSAl Viro generic_fillattr(inode, stat); 7429043476fSAl Viro if (table) 7439043476fSAl Viro stat->mode = (stat->mode & S_IFMT) | table->mode; 7449043476fSAl Viro 7459043476fSAl Viro sysctl_head_finish(head); 7469043476fSAl Viro return 0; 7479043476fSAl Viro } 7489043476fSAl Viro 74977b14db5SEric W. Biederman static const struct file_operations proc_sys_file_operations = { 750f1ecf068SLucas De Marchi .open = proc_sys_open, 751f1ecf068SLucas De Marchi .poll = proc_sys_poll, 75277b14db5SEric W. Biederman .read = proc_sys_read, 75377b14db5SEric W. Biederman .write = proc_sys_write, 7546038f373SArnd Bergmann .llseek = default_llseek, 7559043476fSAl Viro }; 7569043476fSAl Viro 7579043476fSAl Viro static const struct file_operations proc_sys_dir_file_operations = { 758887df078SPavel Emelyanov .read = generic_read_dir, 75977b14db5SEric W. Biederman .readdir = proc_sys_readdir, 7603222a3e5SChristoph Hellwig .llseek = generic_file_llseek, 76177b14db5SEric W. Biederman }; 76277b14db5SEric W. Biederman 76303a44825SJan Engelhardt static const struct inode_operations proc_sys_inode_operations = { 7649043476fSAl Viro .permission = proc_sys_permission, 7659043476fSAl Viro .setattr = proc_sys_setattr, 7669043476fSAl Viro .getattr = proc_sys_getattr, 7679043476fSAl Viro }; 7689043476fSAl Viro 7699043476fSAl Viro static const struct inode_operations proc_sys_dir_operations = { 77077b14db5SEric W. Biederman .lookup = proc_sys_lookup, 77177b14db5SEric W. Biederman .permission = proc_sys_permission, 77277b14db5SEric W. Biederman .setattr = proc_sys_setattr, 7739043476fSAl Viro .getattr = proc_sys_getattr, 77477b14db5SEric W. Biederman }; 77577b14db5SEric W. Biederman 77677b14db5SEric W. Biederman static int proc_sys_revalidate(struct dentry *dentry, struct nameidata *nd) 77777b14db5SEric W. Biederman { 77834286d66SNick Piggin if (nd->flags & LOOKUP_RCU) 77934286d66SNick Piggin return -ECHILD; 7809043476fSAl Viro return !PROC_I(dentry->d_inode)->sysctl->unregistering; 7819043476fSAl Viro } 7829043476fSAl Viro 783fe15ce44SNick Piggin static int proc_sys_delete(const struct dentry *dentry) 7849043476fSAl Viro { 7859043476fSAl Viro return !!PROC_I(dentry->d_inode)->sysctl->unregistering; 7869043476fSAl Viro } 7879043476fSAl Viro 7881f87f0b5SEric W. Biederman static int sysctl_is_seen(struct ctl_table_header *p) 7891f87f0b5SEric W. Biederman { 7901f87f0b5SEric W. Biederman struct ctl_table_set *set = p->set; 7911f87f0b5SEric W. Biederman int res; 7921f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 7931f87f0b5SEric W. Biederman if (p->unregistering) 7941f87f0b5SEric W. Biederman res = 0; 7951f87f0b5SEric W. Biederman else if (!set->is_seen) 7961f87f0b5SEric W. Biederman res = 1; 7971f87f0b5SEric W. Biederman else 7981f87f0b5SEric W. Biederman res = set->is_seen(set); 7991f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 8001f87f0b5SEric W. Biederman return res; 8011f87f0b5SEric W. Biederman } 8021f87f0b5SEric W. Biederman 803621e155aSNick Piggin static int proc_sys_compare(const struct dentry *parent, 804621e155aSNick Piggin const struct inode *pinode, 805621e155aSNick Piggin const struct dentry *dentry, const struct inode *inode, 806621e155aSNick Piggin unsigned int len, const char *str, const struct qstr *name) 8079043476fSAl Viro { 808dfef6dcdSAl Viro struct ctl_table_header *head; 80931e6b01fSNick Piggin /* Although proc doesn't have negative dentries, rcu-walk means 81031e6b01fSNick Piggin * that inode here can be NULL */ 811dfef6dcdSAl Viro /* AV: can it, indeed? */ 81231e6b01fSNick Piggin if (!inode) 813dfef6dcdSAl Viro return 1; 814621e155aSNick Piggin if (name->len != len) 8159043476fSAl Viro return 1; 816621e155aSNick Piggin if (memcmp(name->name, str, len)) 8179043476fSAl Viro return 1; 818dfef6dcdSAl Viro head = rcu_dereference(PROC_I(inode)->sysctl); 819dfef6dcdSAl Viro return !head || !sysctl_is_seen(head); 82077b14db5SEric W. Biederman } 82177b14db5SEric W. Biederman 822d72f71ebSAl Viro static const struct dentry_operations proc_sys_dentry_operations = { 82377b14db5SEric W. Biederman .d_revalidate = proc_sys_revalidate, 8249043476fSAl Viro .d_delete = proc_sys_delete, 8259043476fSAl Viro .d_compare = proc_sys_compare, 82677b14db5SEric W. Biederman }; 82777b14db5SEric W. Biederman 8280e47c99dSEric W. Biederman static struct ctl_dir *find_subdir(struct ctl_dir *dir, 8297ec66d06SEric W. Biederman const char *name, int namelen) 8301f87f0b5SEric W. Biederman { 8317ec66d06SEric W. Biederman struct ctl_table_header *head; 8327ec66d06SEric W. Biederman struct ctl_table *entry; 8331f87f0b5SEric W. Biederman 8340e47c99dSEric W. Biederman entry = find_entry(&head, dir, name, namelen); 8357ec66d06SEric W. Biederman if (!entry) 8367ec66d06SEric W. Biederman return ERR_PTR(-ENOENT); 83751f72f4aSEric W. Biederman if (!S_ISDIR(entry->mode)) 8387ec66d06SEric W. Biederman return ERR_PTR(-ENOTDIR); 83951f72f4aSEric W. Biederman return container_of(head, struct ctl_dir, header); 8401f87f0b5SEric W. Biederman } 8411f87f0b5SEric W. Biederman 8427ec66d06SEric W. Biederman static struct ctl_dir *new_dir(struct ctl_table_set *set, 8437ec66d06SEric W. Biederman const char *name, int namelen) 8441f87f0b5SEric W. Biederman { 8457ec66d06SEric W. Biederman struct ctl_table *table; 8467ec66d06SEric W. Biederman struct ctl_dir *new; 847ac13ac6fSEric W. Biederman struct ctl_node *node; 8487ec66d06SEric W. Biederman char *new_name; 8491f87f0b5SEric W. Biederman 850ac13ac6fSEric W. Biederman new = kzalloc(sizeof(*new) + sizeof(struct ctl_node) + 851ac13ac6fSEric W. Biederman sizeof(struct ctl_table)*2 + namelen + 1, 852ac13ac6fSEric W. Biederman GFP_KERNEL); 8537ec66d06SEric W. Biederman if (!new) 8547ec66d06SEric W. Biederman return NULL; 8557ec66d06SEric W. Biederman 856ac13ac6fSEric W. Biederman node = (struct ctl_node *)(new + 1); 857ac13ac6fSEric W. Biederman table = (struct ctl_table *)(node + 1); 8587ec66d06SEric W. Biederman new_name = (char *)(table + 2); 8597ec66d06SEric W. Biederman memcpy(new_name, name, namelen); 8607ec66d06SEric W. Biederman new_name[namelen] = '\0'; 8617ec66d06SEric W. Biederman table[0].procname = new_name; 8627ec66d06SEric W. Biederman table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO; 863ac13ac6fSEric W. Biederman init_header(&new->header, set->dir.header.root, set, node, table); 8647ec66d06SEric W. Biederman 8657ec66d06SEric W. Biederman return new; 8661f87f0b5SEric W. Biederman } 8671f87f0b5SEric W. Biederman 86860f126d9SEric W. Biederman /** 86960f126d9SEric W. Biederman * get_subdir - find or create a subdir with the specified name. 87060f126d9SEric W. Biederman * @dir: Directory to create the subdirectory in 87160f126d9SEric W. Biederman * @name: The name of the subdirectory to find or create 87260f126d9SEric W. Biederman * @namelen: The length of name 87360f126d9SEric W. Biederman * 87460f126d9SEric W. Biederman * Takes a directory with an elevated reference count so we know that 87560f126d9SEric W. Biederman * if we drop the lock the directory will not go away. Upon success 87660f126d9SEric W. Biederman * the reference is moved from @dir to the returned subdirectory. 87760f126d9SEric W. Biederman * Upon error an error code is returned and the reference on @dir is 87860f126d9SEric W. Biederman * simply dropped. 87960f126d9SEric W. Biederman */ 8800e47c99dSEric W. Biederman static struct ctl_dir *get_subdir(struct ctl_dir *dir, 8810e47c99dSEric W. Biederman const char *name, int namelen) 8827ec66d06SEric W. Biederman { 8830e47c99dSEric W. Biederman struct ctl_table_set *set = dir->header.set; 8847ec66d06SEric W. Biederman struct ctl_dir *subdir, *new = NULL; 8850eb97f38SEric W. Biederman int err; 8867ec66d06SEric W. Biederman 8877ec66d06SEric W. Biederman spin_lock(&sysctl_lock); 8880e47c99dSEric W. Biederman subdir = find_subdir(dir, name, namelen); 8897ec66d06SEric W. Biederman if (!IS_ERR(subdir)) 8907ec66d06SEric W. Biederman goto found; 8917ec66d06SEric W. Biederman if (PTR_ERR(subdir) != -ENOENT) 8927ec66d06SEric W. Biederman goto failed; 8937ec66d06SEric W. Biederman 8947ec66d06SEric W. Biederman spin_unlock(&sysctl_lock); 8957ec66d06SEric W. Biederman new = new_dir(set, name, namelen); 8967ec66d06SEric W. Biederman spin_lock(&sysctl_lock); 8977ec66d06SEric W. Biederman subdir = ERR_PTR(-ENOMEM); 8987ec66d06SEric W. Biederman if (!new) 8997ec66d06SEric W. Biederman goto failed; 9007ec66d06SEric W. Biederman 90160f126d9SEric W. Biederman /* Was the subdir added while we dropped the lock? */ 9020e47c99dSEric W. Biederman subdir = find_subdir(dir, name, namelen); 9037ec66d06SEric W. Biederman if (!IS_ERR(subdir)) 9047ec66d06SEric W. Biederman goto found; 9057ec66d06SEric W. Biederman if (PTR_ERR(subdir) != -ENOENT) 9067ec66d06SEric W. Biederman goto failed; 9077ec66d06SEric W. Biederman 90860f126d9SEric W. Biederman /* Nope. Use the our freshly made directory entry. */ 9090eb97f38SEric W. Biederman err = insert_header(dir, &new->header); 9100eb97f38SEric W. Biederman subdir = ERR_PTR(err); 9110eb97f38SEric W. Biederman if (err) 9120e47c99dSEric W. Biederman goto failed; 9137ec66d06SEric W. Biederman subdir = new; 9147ec66d06SEric W. Biederman found: 9157ec66d06SEric W. Biederman subdir->header.nreg++; 9167ec66d06SEric W. Biederman failed: 9177ec66d06SEric W. Biederman if (unlikely(IS_ERR(subdir))) { 9186980128fSEric W. Biederman printk(KERN_ERR "sysctl could not get directory: "); 9196980128fSEric W. Biederman sysctl_print_dir(dir); 9206980128fSEric W. Biederman printk(KERN_CONT "/%*.*s %ld\n", 9217ec66d06SEric W. Biederman namelen, namelen, name, PTR_ERR(subdir)); 9221f87f0b5SEric W. Biederman } 9237ec66d06SEric W. Biederman drop_sysctl_table(&dir->header); 9247ec66d06SEric W. Biederman if (new) 9257ec66d06SEric W. Biederman drop_sysctl_table(&new->header); 9267ec66d06SEric W. Biederman spin_unlock(&sysctl_lock); 9277ec66d06SEric W. Biederman return subdir; 9281f87f0b5SEric W. Biederman } 9291f87f0b5SEric W. Biederman 9300e47c99dSEric W. Biederman static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir) 9310e47c99dSEric W. Biederman { 9320e47c99dSEric W. Biederman struct ctl_dir *parent; 9330e47c99dSEric W. Biederman const char *procname; 9340e47c99dSEric W. Biederman if (!dir->header.parent) 9350e47c99dSEric W. Biederman return &set->dir; 9360e47c99dSEric W. Biederman parent = xlate_dir(set, dir->header.parent); 9370e47c99dSEric W. Biederman if (IS_ERR(parent)) 9380e47c99dSEric W. Biederman return parent; 9390e47c99dSEric W. Biederman procname = dir->header.ctl_table[0].procname; 9400e47c99dSEric W. Biederman return find_subdir(parent, procname, strlen(procname)); 9410e47c99dSEric W. Biederman } 9420e47c99dSEric W. Biederman 9430e47c99dSEric W. Biederman static int sysctl_follow_link(struct ctl_table_header **phead, 9440e47c99dSEric W. Biederman struct ctl_table **pentry, struct nsproxy *namespaces) 9450e47c99dSEric W. Biederman { 9460e47c99dSEric W. Biederman struct ctl_table_header *head; 9470e47c99dSEric W. Biederman struct ctl_table_root *root; 9480e47c99dSEric W. Biederman struct ctl_table_set *set; 9490e47c99dSEric W. Biederman struct ctl_table *entry; 9500e47c99dSEric W. Biederman struct ctl_dir *dir; 9510e47c99dSEric W. Biederman int ret; 9520e47c99dSEric W. Biederman 9530e47c99dSEric W. Biederman /* Get out quickly if not a link */ 9540e47c99dSEric W. Biederman if (!S_ISLNK((*pentry)->mode)) 9550e47c99dSEric W. Biederman return 0; 9560e47c99dSEric W. Biederman 9570e47c99dSEric W. Biederman ret = 0; 9580e47c99dSEric W. Biederman spin_lock(&sysctl_lock); 9590e47c99dSEric W. Biederman root = (*pentry)->data; 9600e47c99dSEric W. Biederman set = lookup_header_set(root, namespaces); 9610e47c99dSEric W. Biederman dir = xlate_dir(set, (*phead)->parent); 9620e47c99dSEric W. Biederman if (IS_ERR(dir)) 9630e47c99dSEric W. Biederman ret = PTR_ERR(dir); 9640e47c99dSEric W. Biederman else { 9650e47c99dSEric W. Biederman const char *procname = (*pentry)->procname; 9660e47c99dSEric W. Biederman head = NULL; 9670e47c99dSEric W. Biederman entry = find_entry(&head, dir, procname, strlen(procname)); 9680e47c99dSEric W. Biederman ret = -ENOENT; 9690e47c99dSEric W. Biederman if (entry && use_table(head)) { 9700e47c99dSEric W. Biederman unuse_table(*phead); 9710e47c99dSEric W. Biederman *phead = head; 9720e47c99dSEric W. Biederman *pentry = entry; 9730e47c99dSEric W. Biederman ret = 0; 9740e47c99dSEric W. Biederman } 9750e47c99dSEric W. Biederman } 9760e47c99dSEric W. Biederman 9770e47c99dSEric W. Biederman spin_unlock(&sysctl_lock); 9780e47c99dSEric W. Biederman return ret; 9790e47c99dSEric W. Biederman } 9800e47c99dSEric W. Biederman 9817c60c48fSEric W. Biederman static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...) 9827c60c48fSEric W. Biederman { 9837c60c48fSEric W. Biederman struct va_format vaf; 9847c60c48fSEric W. Biederman va_list args; 9857c60c48fSEric W. Biederman 9867c60c48fSEric W. Biederman va_start(args, fmt); 9877c60c48fSEric W. Biederman vaf.fmt = fmt; 9887c60c48fSEric W. Biederman vaf.va = &args; 9897c60c48fSEric W. Biederman 9907c60c48fSEric W. Biederman printk(KERN_ERR "sysctl table check failed: %s/%s %pV\n", 9917c60c48fSEric W. Biederman path, table->procname, &vaf); 9927c60c48fSEric W. Biederman 9937c60c48fSEric W. Biederman va_end(args); 9947c60c48fSEric W. Biederman return -EINVAL; 9957c60c48fSEric W. Biederman } 9967c60c48fSEric W. Biederman 9977c60c48fSEric W. Biederman static int sysctl_check_table(const char *path, struct ctl_table *table) 9987c60c48fSEric W. Biederman { 9997c60c48fSEric W. Biederman int err = 0; 10007c60c48fSEric W. Biederman for (; table->procname; table++) { 10017c60c48fSEric W. Biederman if (table->child) 10027c60c48fSEric W. Biederman err = sysctl_err(path, table, "Not a file"); 10037c60c48fSEric W. Biederman 10041f87f0b5SEric W. Biederman if ((table->proc_handler == proc_dostring) || 10051f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec) || 10061f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_minmax) || 10071f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_jiffies) || 10081f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_userhz_jiffies) || 10091f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_ms_jiffies) || 10101f87f0b5SEric W. Biederman (table->proc_handler == proc_doulongvec_minmax) || 10111f87f0b5SEric W. Biederman (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) { 10121f87f0b5SEric W. Biederman if (!table->data) 10137c60c48fSEric W. Biederman err = sysctl_err(path, table, "No data"); 10141f87f0b5SEric W. Biederman if (!table->maxlen) 10157c60c48fSEric W. Biederman err = sysctl_err(path, table, "No maxlen"); 10161f87f0b5SEric W. Biederman } 10171f87f0b5SEric W. Biederman if (!table->proc_handler) 10187c60c48fSEric W. Biederman err = sysctl_err(path, table, "No proc_handler"); 10197c60c48fSEric W. Biederman 10207c60c48fSEric W. Biederman if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode) 10217c60c48fSEric W. Biederman err = sysctl_err(path, table, "bogus .mode 0%o", 10227c60c48fSEric W. Biederman table->mode); 10231f87f0b5SEric W. Biederman } 10247c60c48fSEric W. Biederman return err; 10251f87f0b5SEric W. Biederman } 10261f87f0b5SEric W. Biederman 10270e47c99dSEric W. Biederman static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table *table, 10280e47c99dSEric W. Biederman struct ctl_table_root *link_root) 10290e47c99dSEric W. Biederman { 10300e47c99dSEric W. Biederman struct ctl_table *link_table, *entry, *link; 10310e47c99dSEric W. Biederman struct ctl_table_header *links; 1032ac13ac6fSEric W. Biederman struct ctl_node *node; 10330e47c99dSEric W. Biederman char *link_name; 10340e47c99dSEric W. Biederman int nr_entries, name_bytes; 10350e47c99dSEric W. Biederman 10360e47c99dSEric W. Biederman name_bytes = 0; 10370e47c99dSEric W. Biederman nr_entries = 0; 10380e47c99dSEric W. Biederman for (entry = table; entry->procname; entry++) { 10390e47c99dSEric W. Biederman nr_entries++; 10400e47c99dSEric W. Biederman name_bytes += strlen(entry->procname) + 1; 10410e47c99dSEric W. Biederman } 10420e47c99dSEric W. Biederman 10430e47c99dSEric W. Biederman links = kzalloc(sizeof(struct ctl_table_header) + 1044ac13ac6fSEric W. Biederman sizeof(struct ctl_node)*nr_entries + 10450e47c99dSEric W. Biederman sizeof(struct ctl_table)*(nr_entries + 1) + 10460e47c99dSEric W. Biederman name_bytes, 10470e47c99dSEric W. Biederman GFP_KERNEL); 10480e47c99dSEric W. Biederman 10490e47c99dSEric W. Biederman if (!links) 10500e47c99dSEric W. Biederman return NULL; 10510e47c99dSEric W. Biederman 1052ac13ac6fSEric W. Biederman node = (struct ctl_node *)(links + 1); 1053ac13ac6fSEric W. Biederman link_table = (struct ctl_table *)(node + nr_entries); 10540e47c99dSEric W. Biederman link_name = (char *)&link_table[nr_entries + 1]; 10550e47c99dSEric W. Biederman 10560e47c99dSEric W. Biederman for (link = link_table, entry = table; entry->procname; link++, entry++) { 10570e47c99dSEric W. Biederman int len = strlen(entry->procname) + 1; 10580e47c99dSEric W. Biederman memcpy(link_name, entry->procname, len); 10590e47c99dSEric W. Biederman link->procname = link_name; 10600e47c99dSEric W. Biederman link->mode = S_IFLNK|S_IRWXUGO; 10610e47c99dSEric W. Biederman link->data = link_root; 10620e47c99dSEric W. Biederman link_name += len; 10630e47c99dSEric W. Biederman } 1064ac13ac6fSEric W. Biederman init_header(links, dir->header.root, dir->header.set, node, link_table); 10650e47c99dSEric W. Biederman links->nreg = nr_entries; 10660e47c99dSEric W. Biederman 10670e47c99dSEric W. Biederman return links; 10680e47c99dSEric W. Biederman } 10690e47c99dSEric W. Biederman 10700e47c99dSEric W. Biederman static bool get_links(struct ctl_dir *dir, 10710e47c99dSEric W. Biederman struct ctl_table *table, struct ctl_table_root *link_root) 10720e47c99dSEric W. Biederman { 10730e47c99dSEric W. Biederman struct ctl_table_header *head; 10740e47c99dSEric W. Biederman struct ctl_table *entry, *link; 10750e47c99dSEric W. Biederman 10760e47c99dSEric W. Biederman /* Are there links available for every entry in table? */ 10770e47c99dSEric W. Biederman for (entry = table; entry->procname; entry++) { 10780e47c99dSEric W. Biederman const char *procname = entry->procname; 10790e47c99dSEric W. Biederman link = find_entry(&head, dir, procname, strlen(procname)); 10800e47c99dSEric W. Biederman if (!link) 10810e47c99dSEric W. Biederman return false; 10820e47c99dSEric W. Biederman if (S_ISDIR(link->mode) && S_ISDIR(entry->mode)) 10830e47c99dSEric W. Biederman continue; 10840e47c99dSEric W. Biederman if (S_ISLNK(link->mode) && (link->data == link_root)) 10850e47c99dSEric W. Biederman continue; 10860e47c99dSEric W. Biederman return false; 10870e47c99dSEric W. Biederman } 10880e47c99dSEric W. Biederman 10890e47c99dSEric W. Biederman /* The checks passed. Increase the registration count on the links */ 10900e47c99dSEric W. Biederman for (entry = table; entry->procname; entry++) { 10910e47c99dSEric W. Biederman const char *procname = entry->procname; 10920e47c99dSEric W. Biederman link = find_entry(&head, dir, procname, strlen(procname)); 10930e47c99dSEric W. Biederman head->nreg++; 10940e47c99dSEric W. Biederman } 10950e47c99dSEric W. Biederman return true; 10960e47c99dSEric W. Biederman } 10970e47c99dSEric W. Biederman 10980e47c99dSEric W. Biederman static int insert_links(struct ctl_table_header *head) 10990e47c99dSEric W. Biederman { 11000e47c99dSEric W. Biederman struct ctl_table_set *root_set = &sysctl_table_root.default_set; 11010e47c99dSEric W. Biederman struct ctl_dir *core_parent = NULL; 11020e47c99dSEric W. Biederman struct ctl_table_header *links; 11030e47c99dSEric W. Biederman int err; 11040e47c99dSEric W. Biederman 11050e47c99dSEric W. Biederman if (head->set == root_set) 11060e47c99dSEric W. Biederman return 0; 11070e47c99dSEric W. Biederman 11080e47c99dSEric W. Biederman core_parent = xlate_dir(root_set, head->parent); 11090e47c99dSEric W. Biederman if (IS_ERR(core_parent)) 11100e47c99dSEric W. Biederman return 0; 11110e47c99dSEric W. Biederman 11120e47c99dSEric W. Biederman if (get_links(core_parent, head->ctl_table, head->root)) 11130e47c99dSEric W. Biederman return 0; 11140e47c99dSEric W. Biederman 11150e47c99dSEric W. Biederman core_parent->header.nreg++; 11160e47c99dSEric W. Biederman spin_unlock(&sysctl_lock); 11170e47c99dSEric W. Biederman 11180e47c99dSEric W. Biederman links = new_links(core_parent, head->ctl_table, head->root); 11190e47c99dSEric W. Biederman 11200e47c99dSEric W. Biederman spin_lock(&sysctl_lock); 11210e47c99dSEric W. Biederman err = -ENOMEM; 11220e47c99dSEric W. Biederman if (!links) 11230e47c99dSEric W. Biederman goto out; 11240e47c99dSEric W. Biederman 11250e47c99dSEric W. Biederman err = 0; 11260e47c99dSEric W. Biederman if (get_links(core_parent, head->ctl_table, head->root)) { 11270e47c99dSEric W. Biederman kfree(links); 11280e47c99dSEric W. Biederman goto out; 11290e47c99dSEric W. Biederman } 11300e47c99dSEric W. Biederman 11310e47c99dSEric W. Biederman err = insert_header(core_parent, links); 11320e47c99dSEric W. Biederman if (err) 11330e47c99dSEric W. Biederman kfree(links); 11340e47c99dSEric W. Biederman out: 11350e47c99dSEric W. Biederman drop_sysctl_table(&core_parent->header); 11360e47c99dSEric W. Biederman return err; 11370e47c99dSEric W. Biederman } 11380e47c99dSEric W. Biederman 11391f87f0b5SEric W. Biederman /** 1140f728019bSEric W. Biederman * __register_sysctl_table - register a leaf sysctl table 114160a47a2eSEric W. Biederman * @set: Sysctl tree to register on 11421f87f0b5SEric W. Biederman * @path: The path to the directory the sysctl table is in. 11431f87f0b5SEric W. Biederman * @table: the top-level table structure 11441f87f0b5SEric W. Biederman * 11451f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 11461f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 11471f87f0b5SEric W. Biederman * 11481f87f0b5SEric W. Biederman * The members of the &struct ctl_table structure are used as follows: 11491f87f0b5SEric W. Biederman * 11501f87f0b5SEric W. Biederman * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not 11511f87f0b5SEric W. Biederman * enter a sysctl file 11521f87f0b5SEric W. Biederman * 11531f87f0b5SEric W. Biederman * data - a pointer to data for use by proc_handler 11541f87f0b5SEric W. Biederman * 11551f87f0b5SEric W. Biederman * maxlen - the maximum size in bytes of the data 11561f87f0b5SEric W. Biederman * 1157f728019bSEric W. Biederman * mode - the file permissions for the /proc/sys file 11581f87f0b5SEric W. Biederman * 1159f728019bSEric W. Biederman * child - must be %NULL. 11601f87f0b5SEric W. Biederman * 11611f87f0b5SEric W. Biederman * proc_handler - the text handler routine (described below) 11621f87f0b5SEric W. Biederman * 11631f87f0b5SEric W. Biederman * extra1, extra2 - extra pointers usable by the proc handler routines 11641f87f0b5SEric W. Biederman * 11651f87f0b5SEric W. Biederman * Leaf nodes in the sysctl tree will be represented by a single file 11661f87f0b5SEric W. Biederman * under /proc; non-leaf nodes will be represented by directories. 11671f87f0b5SEric W. Biederman * 1168f728019bSEric W. Biederman * There must be a proc_handler routine for any terminal nodes. 1169f728019bSEric W. Biederman * Several default handlers are available to cover common cases - 11701f87f0b5SEric W. Biederman * 11711f87f0b5SEric W. Biederman * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), 11721f87f0b5SEric W. Biederman * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 11731f87f0b5SEric W. Biederman * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() 11741f87f0b5SEric W. Biederman * 11751f87f0b5SEric W. Biederman * It is the handler's job to read the input buffer from user memory 11761f87f0b5SEric W. Biederman * and process it. The handler should return 0 on success. 11771f87f0b5SEric W. Biederman * 11781f87f0b5SEric W. Biederman * This routine returns %NULL on a failure to register, and a pointer 11791f87f0b5SEric W. Biederman * to the table header on success. 11801f87f0b5SEric W. Biederman */ 11816e9d5164SEric W. Biederman struct ctl_table_header *__register_sysctl_table( 118260a47a2eSEric W. Biederman struct ctl_table_set *set, 11836e9d5164SEric W. Biederman const char *path, struct ctl_table *table) 11841f87f0b5SEric W. Biederman { 118560a47a2eSEric W. Biederman struct ctl_table_root *root = set->dir.header.root; 11861f87f0b5SEric W. Biederman struct ctl_table_header *header; 11876e9d5164SEric W. Biederman const char *name, *nextname; 11887ec66d06SEric W. Biederman struct ctl_dir *dir; 1189ac13ac6fSEric W. Biederman struct ctl_table *entry; 1190ac13ac6fSEric W. Biederman struct ctl_node *node; 1191ac13ac6fSEric W. Biederman int nr_entries = 0; 11921f87f0b5SEric W. Biederman 1193ac13ac6fSEric W. Biederman for (entry = table; entry->procname; entry++) 1194ac13ac6fSEric W. Biederman nr_entries++; 1195ac13ac6fSEric W. Biederman 1196ac13ac6fSEric W. Biederman header = kzalloc(sizeof(struct ctl_table_header) + 1197ac13ac6fSEric W. Biederman sizeof(struct ctl_node)*nr_entries, GFP_KERNEL); 11981f87f0b5SEric W. Biederman if (!header) 11991f87f0b5SEric W. Biederman return NULL; 12001f87f0b5SEric W. Biederman 1201ac13ac6fSEric W. Biederman node = (struct ctl_node *)(header + 1); 1202ac13ac6fSEric W. Biederman init_header(header, root, set, node, table); 12037c60c48fSEric W. Biederman if (sysctl_check_table(path, table)) 12047c60c48fSEric W. Biederman goto fail; 12058d6ecfccSEric W. Biederman 12061f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 12070e47c99dSEric W. Biederman dir = &set->dir; 120860f126d9SEric W. Biederman /* Reference moved down the diretory tree get_subdir */ 12097ec66d06SEric W. Biederman dir->header.nreg++; 12107ec66d06SEric W. Biederman spin_unlock(&sysctl_lock); 12117ec66d06SEric W. Biederman 12127ec66d06SEric W. Biederman /* Find the directory for the ctl_table */ 12137ec66d06SEric W. Biederman for (name = path; name; name = nextname) { 12147ec66d06SEric W. Biederman int namelen; 12157ec66d06SEric W. Biederman nextname = strchr(name, '/'); 12167ec66d06SEric W. Biederman if (nextname) { 12177ec66d06SEric W. Biederman namelen = nextname - name; 12187ec66d06SEric W. Biederman nextname++; 12197ec66d06SEric W. Biederman } else { 12207ec66d06SEric W. Biederman namelen = strlen(name); 12217ec66d06SEric W. Biederman } 12227ec66d06SEric W. Biederman if (namelen == 0) 12231f87f0b5SEric W. Biederman continue; 12247ec66d06SEric W. Biederman 12250e47c99dSEric W. Biederman dir = get_subdir(dir, name, namelen); 12267ec66d06SEric W. Biederman if (IS_ERR(dir)) 12277ec66d06SEric W. Biederman goto fail; 12281f87f0b5SEric W. Biederman } 12290e47c99dSEric W. Biederman 12307ec66d06SEric W. Biederman spin_lock(&sysctl_lock); 12310e47c99dSEric W. Biederman if (insert_header(dir, header)) 12320e47c99dSEric W. Biederman goto fail_put_dir_locked; 12330e47c99dSEric W. Biederman 12347ec66d06SEric W. Biederman drop_sysctl_table(&dir->header); 12351f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 12361f87f0b5SEric W. Biederman 12371f87f0b5SEric W. Biederman return header; 12380e47c99dSEric W. Biederman 12397ec66d06SEric W. Biederman fail_put_dir_locked: 12407ec66d06SEric W. Biederman drop_sysctl_table(&dir->header); 12417c60c48fSEric W. Biederman spin_unlock(&sysctl_lock); 12427c60c48fSEric W. Biederman fail: 12437c60c48fSEric W. Biederman kfree(header); 12447c60c48fSEric W. Biederman dump_stack(); 12457c60c48fSEric W. Biederman return NULL; 12461f87f0b5SEric W. Biederman } 12471f87f0b5SEric W. Biederman 1248fea478d4SEric W. Biederman /** 1249fea478d4SEric W. Biederman * register_sysctl - register a sysctl table 1250fea478d4SEric W. Biederman * @path: The path to the directory the sysctl table is in. 1251fea478d4SEric W. Biederman * @table: the table structure 1252fea478d4SEric W. Biederman * 1253fea478d4SEric W. Biederman * Register a sysctl table. @table should be a filled in ctl_table 1254fea478d4SEric W. Biederman * array. A completely 0 filled entry terminates the table. 1255fea478d4SEric W. Biederman * 1256fea478d4SEric W. Biederman * See __register_sysctl_table for more details. 1257fea478d4SEric W. Biederman */ 1258fea478d4SEric W. Biederman struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) 1259fea478d4SEric W. Biederman { 1260fea478d4SEric W. Biederman return __register_sysctl_table(&sysctl_table_root.default_set, 1261fea478d4SEric W. Biederman path, table); 1262fea478d4SEric W. Biederman } 1263fea478d4SEric W. Biederman EXPORT_SYMBOL(register_sysctl); 1264fea478d4SEric W. Biederman 12656e9d5164SEric W. Biederman static char *append_path(const char *path, char *pos, const char *name) 12666e9d5164SEric W. Biederman { 12676e9d5164SEric W. Biederman int namelen; 12686e9d5164SEric W. Biederman namelen = strlen(name); 12696e9d5164SEric W. Biederman if (((pos - path) + namelen + 2) >= PATH_MAX) 12706e9d5164SEric W. Biederman return NULL; 12716e9d5164SEric W. Biederman memcpy(pos, name, namelen); 12726e9d5164SEric W. Biederman pos[namelen] = '/'; 12736e9d5164SEric W. Biederman pos[namelen + 1] = '\0'; 12746e9d5164SEric W. Biederman pos += namelen + 1; 12756e9d5164SEric W. Biederman return pos; 12766e9d5164SEric W. Biederman } 12776e9d5164SEric W. Biederman 1278f728019bSEric W. Biederman static int count_subheaders(struct ctl_table *table) 1279f728019bSEric W. Biederman { 1280f728019bSEric W. Biederman int has_files = 0; 1281f728019bSEric W. Biederman int nr_subheaders = 0; 1282f728019bSEric W. Biederman struct ctl_table *entry; 1283f728019bSEric W. Biederman 1284f728019bSEric W. Biederman /* special case: no directory and empty directory */ 1285f728019bSEric W. Biederman if (!table || !table->procname) 1286f728019bSEric W. Biederman return 1; 1287f728019bSEric W. Biederman 1288f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1289f728019bSEric W. Biederman if (entry->child) 1290f728019bSEric W. Biederman nr_subheaders += count_subheaders(entry->child); 1291f728019bSEric W. Biederman else 1292f728019bSEric W. Biederman has_files = 1; 1293f728019bSEric W. Biederman } 1294f728019bSEric W. Biederman return nr_subheaders + has_files; 1295f728019bSEric W. Biederman } 1296f728019bSEric W. Biederman 1297f728019bSEric W. Biederman static int register_leaf_sysctl_tables(const char *path, char *pos, 129860a47a2eSEric W. Biederman struct ctl_table_header ***subheader, struct ctl_table_set *set, 1299f728019bSEric W. Biederman struct ctl_table *table) 1300f728019bSEric W. Biederman { 1301f728019bSEric W. Biederman struct ctl_table *ctl_table_arg = NULL; 1302f728019bSEric W. Biederman struct ctl_table *entry, *files; 1303f728019bSEric W. Biederman int nr_files = 0; 1304f728019bSEric W. Biederman int nr_dirs = 0; 1305f728019bSEric W. Biederman int err = -ENOMEM; 1306f728019bSEric W. Biederman 1307f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1308f728019bSEric W. Biederman if (entry->child) 1309f728019bSEric W. Biederman nr_dirs++; 1310f728019bSEric W. Biederman else 1311f728019bSEric W. Biederman nr_files++; 1312f728019bSEric W. Biederman } 1313f728019bSEric W. Biederman 1314f728019bSEric W. Biederman files = table; 1315f728019bSEric W. Biederman /* If there are mixed files and directories we need a new table */ 1316f728019bSEric W. Biederman if (nr_dirs && nr_files) { 1317f728019bSEric W. Biederman struct ctl_table *new; 1318f728019bSEric W. Biederman files = kzalloc(sizeof(struct ctl_table) * (nr_files + 1), 1319f728019bSEric W. Biederman GFP_KERNEL); 1320f728019bSEric W. Biederman if (!files) 1321f728019bSEric W. Biederman goto out; 1322f728019bSEric W. Biederman 1323f728019bSEric W. Biederman ctl_table_arg = files; 1324f728019bSEric W. Biederman for (new = files, entry = table; entry->procname; entry++) { 1325f728019bSEric W. Biederman if (entry->child) 1326f728019bSEric W. Biederman continue; 1327f728019bSEric W. Biederman *new = *entry; 1328f728019bSEric W. Biederman new++; 1329f728019bSEric W. Biederman } 1330f728019bSEric W. Biederman } 1331f728019bSEric W. Biederman 1332f728019bSEric W. Biederman /* Register everything except a directory full of subdirectories */ 1333f728019bSEric W. Biederman if (nr_files || !nr_dirs) { 1334f728019bSEric W. Biederman struct ctl_table_header *header; 133560a47a2eSEric W. Biederman header = __register_sysctl_table(set, path, files); 1336f728019bSEric W. Biederman if (!header) { 1337f728019bSEric W. Biederman kfree(ctl_table_arg); 1338f728019bSEric W. Biederman goto out; 1339f728019bSEric W. Biederman } 1340f728019bSEric W. Biederman 1341f728019bSEric W. Biederman /* Remember if we need to free the file table */ 1342f728019bSEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1343f728019bSEric W. Biederman **subheader = header; 1344f728019bSEric W. Biederman (*subheader)++; 1345f728019bSEric W. Biederman } 1346f728019bSEric W. Biederman 1347f728019bSEric W. Biederman /* Recurse into the subdirectories. */ 1348f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1349f728019bSEric W. Biederman char *child_pos; 1350f728019bSEric W. Biederman 1351f728019bSEric W. Biederman if (!entry->child) 1352f728019bSEric W. Biederman continue; 1353f728019bSEric W. Biederman 1354f728019bSEric W. Biederman err = -ENAMETOOLONG; 1355f728019bSEric W. Biederman child_pos = append_path(path, pos, entry->procname); 1356f728019bSEric W. Biederman if (!child_pos) 1357f728019bSEric W. Biederman goto out; 1358f728019bSEric W. Biederman 1359f728019bSEric W. Biederman err = register_leaf_sysctl_tables(path, child_pos, subheader, 136060a47a2eSEric W. Biederman set, entry->child); 1361f728019bSEric W. Biederman pos[0] = '\0'; 1362f728019bSEric W. Biederman if (err) 1363f728019bSEric W. Biederman goto out; 1364f728019bSEric W. Biederman } 1365f728019bSEric W. Biederman err = 0; 1366f728019bSEric W. Biederman out: 1367f728019bSEric W. Biederman /* On failure our caller will unregister all registered subheaders */ 1368f728019bSEric W. Biederman return err; 1369f728019bSEric W. Biederman } 1370f728019bSEric W. Biederman 13716e9d5164SEric W. Biederman /** 13726e9d5164SEric W. Biederman * __register_sysctl_paths - register a sysctl table hierarchy 137360a47a2eSEric W. Biederman * @set: Sysctl tree to register on 13746e9d5164SEric W. Biederman * @path: The path to the directory the sysctl table is in. 13756e9d5164SEric W. Biederman * @table: the top-level table structure 13766e9d5164SEric W. Biederman * 13776e9d5164SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 13786e9d5164SEric W. Biederman * array. A completely 0 filled entry terminates the table. 13796e9d5164SEric W. Biederman * 13806e9d5164SEric W. Biederman * See __register_sysctl_table for more details. 13816e9d5164SEric W. Biederman */ 13826e9d5164SEric W. Biederman struct ctl_table_header *__register_sysctl_paths( 138360a47a2eSEric W. Biederman struct ctl_table_set *set, 13846e9d5164SEric W. Biederman const struct ctl_path *path, struct ctl_table *table) 13856e9d5164SEric W. Biederman { 1386ec6a5266SEric W. Biederman struct ctl_table *ctl_table_arg = table; 1387f728019bSEric W. Biederman int nr_subheaders = count_subheaders(table); 1388f728019bSEric W. Biederman struct ctl_table_header *header = NULL, **subheaders, **subheader; 13896e9d5164SEric W. Biederman const struct ctl_path *component; 13906e9d5164SEric W. Biederman char *new_path, *pos; 13916e9d5164SEric W. Biederman 13926e9d5164SEric W. Biederman pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); 13936e9d5164SEric W. Biederman if (!new_path) 13946e9d5164SEric W. Biederman return NULL; 13956e9d5164SEric W. Biederman 13966e9d5164SEric W. Biederman pos[0] = '\0'; 13976e9d5164SEric W. Biederman for (component = path; component->procname; component++) { 13986e9d5164SEric W. Biederman pos = append_path(new_path, pos, component->procname); 13996e9d5164SEric W. Biederman if (!pos) 14006e9d5164SEric W. Biederman goto out; 14016e9d5164SEric W. Biederman } 1402ec6a5266SEric W. Biederman while (table->procname && table->child && !table[1].procname) { 1403ec6a5266SEric W. Biederman pos = append_path(new_path, pos, table->procname); 1404ec6a5266SEric W. Biederman if (!pos) 1405ec6a5266SEric W. Biederman goto out; 1406ec6a5266SEric W. Biederman table = table->child; 1407ec6a5266SEric W. Biederman } 1408f728019bSEric W. Biederman if (nr_subheaders == 1) { 140960a47a2eSEric W. Biederman header = __register_sysctl_table(set, new_path, table); 1410ec6a5266SEric W. Biederman if (header) 1411ec6a5266SEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1412f728019bSEric W. Biederman } else { 1413f728019bSEric W. Biederman header = kzalloc(sizeof(*header) + 1414f728019bSEric W. Biederman sizeof(*subheaders)*nr_subheaders, GFP_KERNEL); 1415f728019bSEric W. Biederman if (!header) 1416f728019bSEric W. Biederman goto out; 1417f728019bSEric W. Biederman 1418f728019bSEric W. Biederman subheaders = (struct ctl_table_header **) (header + 1); 1419f728019bSEric W. Biederman subheader = subheaders; 1420f728019bSEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1421f728019bSEric W. Biederman 1422f728019bSEric W. Biederman if (register_leaf_sysctl_tables(new_path, pos, &subheader, 142360a47a2eSEric W. Biederman set, table)) 1424f728019bSEric W. Biederman goto err_register_leaves; 1425f728019bSEric W. Biederman } 1426f728019bSEric W. Biederman 14276e9d5164SEric W. Biederman out: 14286e9d5164SEric W. Biederman kfree(new_path); 14296e9d5164SEric W. Biederman return header; 1430f728019bSEric W. Biederman 1431f728019bSEric W. Biederman err_register_leaves: 1432f728019bSEric W. Biederman while (subheader > subheaders) { 1433f728019bSEric W. Biederman struct ctl_table_header *subh = *(--subheader); 1434f728019bSEric W. Biederman struct ctl_table *table = subh->ctl_table_arg; 1435f728019bSEric W. Biederman unregister_sysctl_table(subh); 1436f728019bSEric W. Biederman kfree(table); 1437f728019bSEric W. Biederman } 1438f728019bSEric W. Biederman kfree(header); 1439f728019bSEric W. Biederman header = NULL; 1440f728019bSEric W. Biederman goto out; 14416e9d5164SEric W. Biederman } 14426e9d5164SEric W. Biederman 14431f87f0b5SEric W. Biederman /** 14441f87f0b5SEric W. Biederman * register_sysctl_table_path - register a sysctl table hierarchy 14451f87f0b5SEric W. Biederman * @path: The path to the directory the sysctl table is in. 14461f87f0b5SEric W. Biederman * @table: the top-level table structure 14471f87f0b5SEric W. Biederman * 14481f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 14491f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 14501f87f0b5SEric W. Biederman * 14511f87f0b5SEric W. Biederman * See __register_sysctl_paths for more details. 14521f87f0b5SEric W. Biederman */ 14531f87f0b5SEric W. Biederman struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, 14541f87f0b5SEric W. Biederman struct ctl_table *table) 14551f87f0b5SEric W. Biederman { 145660a47a2eSEric W. Biederman return __register_sysctl_paths(&sysctl_table_root.default_set, 14571f87f0b5SEric W. Biederman path, table); 14581f87f0b5SEric W. Biederman } 14591f87f0b5SEric W. Biederman EXPORT_SYMBOL(register_sysctl_paths); 14601f87f0b5SEric W. Biederman 14611f87f0b5SEric W. Biederman /** 14621f87f0b5SEric W. Biederman * register_sysctl_table - register a sysctl table hierarchy 14631f87f0b5SEric W. Biederman * @table: the top-level table structure 14641f87f0b5SEric W. Biederman * 14651f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 14661f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 14671f87f0b5SEric W. Biederman * 14681f87f0b5SEric W. Biederman * See register_sysctl_paths for more details. 14691f87f0b5SEric W. Biederman */ 14701f87f0b5SEric W. Biederman struct ctl_table_header *register_sysctl_table(struct ctl_table *table) 14711f87f0b5SEric W. Biederman { 14721f87f0b5SEric W. Biederman static const struct ctl_path null_path[] = { {} }; 14731f87f0b5SEric W. Biederman 14741f87f0b5SEric W. Biederman return register_sysctl_paths(null_path, table); 14751f87f0b5SEric W. Biederman } 14761f87f0b5SEric W. Biederman EXPORT_SYMBOL(register_sysctl_table); 14771f87f0b5SEric W. Biederman 14780e47c99dSEric W. Biederman static void put_links(struct ctl_table_header *header) 14790e47c99dSEric W. Biederman { 14800e47c99dSEric W. Biederman struct ctl_table_set *root_set = &sysctl_table_root.default_set; 14810e47c99dSEric W. Biederman struct ctl_table_root *root = header->root; 14820e47c99dSEric W. Biederman struct ctl_dir *parent = header->parent; 14830e47c99dSEric W. Biederman struct ctl_dir *core_parent; 14840e47c99dSEric W. Biederman struct ctl_table *entry; 14850e47c99dSEric W. Biederman 14860e47c99dSEric W. Biederman if (header->set == root_set) 14870e47c99dSEric W. Biederman return; 14880e47c99dSEric W. Biederman 14890e47c99dSEric W. Biederman core_parent = xlate_dir(root_set, parent); 14900e47c99dSEric W. Biederman if (IS_ERR(core_parent)) 14910e47c99dSEric W. Biederman return; 14920e47c99dSEric W. Biederman 14930e47c99dSEric W. Biederman for (entry = header->ctl_table; entry->procname; entry++) { 14940e47c99dSEric W. Biederman struct ctl_table_header *link_head; 14950e47c99dSEric W. Biederman struct ctl_table *link; 14960e47c99dSEric W. Biederman const char *name = entry->procname; 14970e47c99dSEric W. Biederman 14980e47c99dSEric W. Biederman link = find_entry(&link_head, core_parent, name, strlen(name)); 14990e47c99dSEric W. Biederman if (link && 15000e47c99dSEric W. Biederman ((S_ISDIR(link->mode) && S_ISDIR(entry->mode)) || 15010e47c99dSEric W. Biederman (S_ISLNK(link->mode) && (link->data == root)))) { 15020e47c99dSEric W. Biederman drop_sysctl_table(link_head); 15030e47c99dSEric W. Biederman } 15040e47c99dSEric W. Biederman else { 15050e47c99dSEric W. Biederman printk(KERN_ERR "sysctl link missing during unregister: "); 15060e47c99dSEric W. Biederman sysctl_print_dir(parent); 15070e47c99dSEric W. Biederman printk(KERN_CONT "/%s\n", name); 15080e47c99dSEric W. Biederman } 15090e47c99dSEric W. Biederman } 15100e47c99dSEric W. Biederman } 15110e47c99dSEric W. Biederman 1512938aaa4fSEric W. Biederman static void drop_sysctl_table(struct ctl_table_header *header) 1513938aaa4fSEric W. Biederman { 15147ec66d06SEric W. Biederman struct ctl_dir *parent = header->parent; 15157ec66d06SEric W. Biederman 1516938aaa4fSEric W. Biederman if (--header->nreg) 1517938aaa4fSEric W. Biederman return; 1518938aaa4fSEric W. Biederman 15190e47c99dSEric W. Biederman put_links(header); 1520938aaa4fSEric W. Biederman start_unregistering(header); 1521938aaa4fSEric W. Biederman if (!--header->count) 1522938aaa4fSEric W. Biederman kfree_rcu(header, rcu); 15237ec66d06SEric W. Biederman 15247ec66d06SEric W. Biederman if (parent) 15257ec66d06SEric W. Biederman drop_sysctl_table(&parent->header); 1526938aaa4fSEric W. Biederman } 1527938aaa4fSEric W. Biederman 15281f87f0b5SEric W. Biederman /** 15291f87f0b5SEric W. Biederman * unregister_sysctl_table - unregister a sysctl table hierarchy 15301f87f0b5SEric W. Biederman * @header: the header returned from register_sysctl_table 15311f87f0b5SEric W. Biederman * 15321f87f0b5SEric W. Biederman * Unregisters the sysctl table and all children. proc entries may not 15331f87f0b5SEric W. Biederman * actually be removed until they are no longer used by anyone. 15341f87f0b5SEric W. Biederman */ 15351f87f0b5SEric W. Biederman void unregister_sysctl_table(struct ctl_table_header * header) 15361f87f0b5SEric W. Biederman { 1537f728019bSEric W. Biederman int nr_subheaders; 15381f87f0b5SEric W. Biederman might_sleep(); 15391f87f0b5SEric W. Biederman 15401f87f0b5SEric W. Biederman if (header == NULL) 15411f87f0b5SEric W. Biederman return; 15421f87f0b5SEric W. Biederman 1543f728019bSEric W. Biederman nr_subheaders = count_subheaders(header->ctl_table_arg); 1544f728019bSEric W. Biederman if (unlikely(nr_subheaders > 1)) { 1545f728019bSEric W. Biederman struct ctl_table_header **subheaders; 1546f728019bSEric W. Biederman int i; 1547f728019bSEric W. Biederman 1548f728019bSEric W. Biederman subheaders = (struct ctl_table_header **)(header + 1); 1549f728019bSEric W. Biederman for (i = nr_subheaders -1; i >= 0; i--) { 1550f728019bSEric W. Biederman struct ctl_table_header *subh = subheaders[i]; 1551f728019bSEric W. Biederman struct ctl_table *table = subh->ctl_table_arg; 1552f728019bSEric W. Biederman unregister_sysctl_table(subh); 1553f728019bSEric W. Biederman kfree(table); 1554f728019bSEric W. Biederman } 1555f728019bSEric W. Biederman kfree(header); 1556f728019bSEric W. Biederman return; 1557f728019bSEric W. Biederman } 1558f728019bSEric W. Biederman 15591f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1560938aaa4fSEric W. Biederman drop_sysctl_table(header); 15611f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 15621f87f0b5SEric W. Biederman } 15631f87f0b5SEric W. Biederman EXPORT_SYMBOL(unregister_sysctl_table); 15641f87f0b5SEric W. Biederman 15650e47c99dSEric W. Biederman void setup_sysctl_set(struct ctl_table_set *set, 15669eb47c26SEric W. Biederman struct ctl_table_root *root, 15671f87f0b5SEric W. Biederman int (*is_seen)(struct ctl_table_set *)) 15681f87f0b5SEric W. Biederman { 15691347440dSDan Carpenter memset(set, 0, sizeof(*set)); 15700e47c99dSEric W. Biederman set->is_seen = is_seen; 1571ac13ac6fSEric W. Biederman init_header(&set->dir.header, root, set, NULL, root_table); 15721f87f0b5SEric W. Biederman } 15731f87f0b5SEric W. Biederman 157497324cd8SEric W. Biederman void retire_sysctl_set(struct ctl_table_set *set) 157597324cd8SEric W. Biederman { 1576ac13ac6fSEric W. Biederman WARN_ON(!RB_EMPTY_ROOT(&set->dir.root)); 157797324cd8SEric W. Biederman } 15781f87f0b5SEric W. Biederman 15791e0edd3fSAlexey Dobriyan int __init proc_sys_init(void) 158077b14db5SEric W. Biederman { 1581e1675231SAlexey Dobriyan struct proc_dir_entry *proc_sys_root; 1582e1675231SAlexey Dobriyan 158377b14db5SEric W. Biederman proc_sys_root = proc_mkdir("sys", NULL); 15849043476fSAl Viro proc_sys_root->proc_iops = &proc_sys_dir_operations; 15859043476fSAl Viro proc_sys_root->proc_fops = &proc_sys_dir_file_operations; 158677b14db5SEric W. Biederman proc_sys_root->nlink = 0; 1587de4e83bdSEric W. Biederman 1588de4e83bdSEric W. Biederman return sysctl_init(); 158977b14db5SEric W. Biederman } 1590