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, 39*ac13ac6fSEric 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 76076c3eedSEric W. Biederman static struct ctl_table *find_entry(struct ctl_table_header **phead, 770e47c99dSEric W. Biederman struct ctl_dir *dir, const char *name, int namelen) 78076c3eedSEric W. Biederman { 79076c3eedSEric W. Biederman struct ctl_table_header *head; 80076c3eedSEric W. Biederman struct ctl_table *entry; 81*ac13ac6fSEric W. Biederman struct rb_node *node = dir->root.rb_node; 82076c3eedSEric W. Biederman 83*ac13ac6fSEric W. Biederman while (node) 84*ac13ac6fSEric W. Biederman { 85*ac13ac6fSEric W. Biederman struct ctl_node *ctl_node; 86*ac13ac6fSEric W. Biederman const char *procname; 87*ac13ac6fSEric W. Biederman int cmp; 88*ac13ac6fSEric W. Biederman 89*ac13ac6fSEric W. Biederman ctl_node = rb_entry(node, struct ctl_node, node); 90*ac13ac6fSEric W. Biederman head = ctl_node->header; 91*ac13ac6fSEric W. Biederman entry = &head->ctl_table[ctl_node - head->node]; 92*ac13ac6fSEric W. Biederman procname = entry->procname; 93*ac13ac6fSEric W. Biederman 94*ac13ac6fSEric W. Biederman cmp = namecmp(name, namelen, procname, strlen(procname)); 95*ac13ac6fSEric W. Biederman if (cmp < 0) 96*ac13ac6fSEric W. Biederman node = node->rb_left; 97*ac13ac6fSEric W. Biederman else if (cmp > 0) 98*ac13ac6fSEric W. Biederman node = node->rb_right; 99*ac13ac6fSEric W. Biederman else { 100076c3eedSEric W. Biederman *phead = head; 101076c3eedSEric W. Biederman return entry; 102076c3eedSEric W. Biederman } 103076c3eedSEric W. Biederman } 104076c3eedSEric W. Biederman return NULL; 105076c3eedSEric W. Biederman } 106076c3eedSEric W. Biederman 107*ac13ac6fSEric W. Biederman static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry) 108*ac13ac6fSEric W. Biederman { 109*ac13ac6fSEric W. Biederman struct rb_node *node = &head->node[entry - head->ctl_table].node; 110*ac13ac6fSEric W. Biederman struct rb_node **p = &head->parent->root.rb_node; 111*ac13ac6fSEric W. Biederman struct rb_node *parent = NULL; 112*ac13ac6fSEric W. Biederman const char *name = entry->procname; 113*ac13ac6fSEric W. Biederman int namelen = strlen(name); 114*ac13ac6fSEric W. Biederman 115*ac13ac6fSEric W. Biederman while (*p) { 116*ac13ac6fSEric W. Biederman struct ctl_table_header *parent_head; 117*ac13ac6fSEric W. Biederman struct ctl_table *parent_entry; 118*ac13ac6fSEric W. Biederman struct ctl_node *parent_node; 119*ac13ac6fSEric W. Biederman const char *parent_name; 120*ac13ac6fSEric W. Biederman int cmp; 121*ac13ac6fSEric W. Biederman 122*ac13ac6fSEric W. Biederman parent = *p; 123*ac13ac6fSEric W. Biederman parent_node = rb_entry(parent, struct ctl_node, node); 124*ac13ac6fSEric W. Biederman parent_head = parent_node->header; 125*ac13ac6fSEric W. Biederman parent_entry = &parent_head->ctl_table[parent_node - parent_head->node]; 126*ac13ac6fSEric W. Biederman parent_name = parent_entry->procname; 127*ac13ac6fSEric W. Biederman 128*ac13ac6fSEric W. Biederman cmp = namecmp(name, namelen, parent_name, strlen(parent_name)); 129*ac13ac6fSEric W. Biederman if (cmp < 0) 130*ac13ac6fSEric W. Biederman p = &(*p)->rb_left; 131*ac13ac6fSEric W. Biederman else if (cmp > 0) 132*ac13ac6fSEric W. Biederman p = &(*p)->rb_right; 133*ac13ac6fSEric W. Biederman else { 134*ac13ac6fSEric W. Biederman printk(KERN_ERR "sysctl duplicate entry: "); 135*ac13ac6fSEric W. Biederman sysctl_print_dir(head->parent); 136*ac13ac6fSEric W. Biederman printk(KERN_CONT "/%s\n", entry->procname); 137*ac13ac6fSEric W. Biederman return -EEXIST; 138*ac13ac6fSEric W. Biederman } 139*ac13ac6fSEric W. Biederman } 140*ac13ac6fSEric W. Biederman 141*ac13ac6fSEric W. Biederman rb_link_node(node, parent, p); 142*ac13ac6fSEric W. Biederman return 0; 143*ac13ac6fSEric W. Biederman } 144*ac13ac6fSEric W. Biederman 145*ac13ac6fSEric W. Biederman static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry) 146*ac13ac6fSEric W. Biederman { 147*ac13ac6fSEric W. Biederman struct rb_node *node = &head->node[entry - head->ctl_table].node; 148*ac13ac6fSEric W. Biederman 149*ac13ac6fSEric W. Biederman rb_erase(node, &head->parent->root); 150*ac13ac6fSEric W. Biederman } 151*ac13ac6fSEric W. Biederman 152e0d04529SEric W. Biederman static void init_header(struct ctl_table_header *head, 153e0d04529SEric W. Biederman struct ctl_table_root *root, struct ctl_table_set *set, 154*ac13ac6fSEric W. Biederman struct ctl_node *node, struct ctl_table *table) 155e0d04529SEric W. Biederman { 1567ec66d06SEric W. Biederman head->ctl_table = table; 157e0d04529SEric W. Biederman head->ctl_table_arg = table; 158e0d04529SEric W. Biederman head->used = 0; 159e0d04529SEric W. Biederman head->count = 1; 160e0d04529SEric W. Biederman head->nreg = 1; 161e0d04529SEric W. Biederman head->unregistering = NULL; 162e0d04529SEric W. Biederman head->root = root; 163e0d04529SEric W. Biederman head->set = set; 164e0d04529SEric W. Biederman head->parent = NULL; 165*ac13ac6fSEric W. Biederman head->node = node; 166*ac13ac6fSEric W. Biederman if (node) { 167*ac13ac6fSEric W. Biederman struct ctl_table *entry; 168*ac13ac6fSEric W. Biederman for (entry = table; entry->procname; entry++, node++) { 169*ac13ac6fSEric W. Biederman rb_init_node(&node->node); 170*ac13ac6fSEric W. Biederman node->header = head; 171*ac13ac6fSEric W. Biederman } 172*ac13ac6fSEric W. Biederman } 173e0d04529SEric W. Biederman } 174e0d04529SEric W. Biederman 1758425d6aaSEric W. Biederman static void erase_header(struct ctl_table_header *head) 1768425d6aaSEric W. Biederman { 177*ac13ac6fSEric W. Biederman struct ctl_table *entry; 178*ac13ac6fSEric W. Biederman for (entry = head->ctl_table; entry->procname; entry++) 179*ac13ac6fSEric W. Biederman erase_entry(head, entry); 1808425d6aaSEric W. Biederman } 1818425d6aaSEric W. Biederman 1820e47c99dSEric W. Biederman static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) 1838425d6aaSEric W. Biederman { 184*ac13ac6fSEric W. Biederman struct ctl_table *entry; 1850e47c99dSEric W. Biederman int err; 1860e47c99dSEric W. Biederman 1870e47c99dSEric W. Biederman dir->header.nreg++; 1887ec66d06SEric W. Biederman header->parent = dir; 1890e47c99dSEric W. Biederman err = insert_links(header); 1900e47c99dSEric W. Biederman if (err) 1910e47c99dSEric W. Biederman goto fail_links; 192*ac13ac6fSEric W. Biederman for (entry = header->ctl_table; entry->procname; entry++) { 193*ac13ac6fSEric W. Biederman err = insert_entry(header, entry); 194*ac13ac6fSEric W. Biederman if (err) 195*ac13ac6fSEric W. Biederman goto fail; 196*ac13ac6fSEric W. Biederman } 1970e47c99dSEric W. Biederman return 0; 198*ac13ac6fSEric W. Biederman fail: 199*ac13ac6fSEric W. Biederman erase_header(header); 200*ac13ac6fSEric W. Biederman put_links(header); 2010e47c99dSEric W. Biederman fail_links: 2020e47c99dSEric W. Biederman header->parent = NULL; 2030e47c99dSEric W. Biederman drop_sysctl_table(&dir->header); 2040e47c99dSEric W. Biederman return err; 2058425d6aaSEric W. Biederman } 2068425d6aaSEric W. Biederman 2071f87f0b5SEric W. Biederman /* called under sysctl_lock */ 2081f87f0b5SEric W. Biederman static int use_table(struct ctl_table_header *p) 2091f87f0b5SEric W. Biederman { 2101f87f0b5SEric W. Biederman if (unlikely(p->unregistering)) 2111f87f0b5SEric W. Biederman return 0; 2121f87f0b5SEric W. Biederman p->used++; 2131f87f0b5SEric W. Biederman return 1; 2141f87f0b5SEric W. Biederman } 2151f87f0b5SEric W. Biederman 2161f87f0b5SEric W. Biederman /* called under sysctl_lock */ 2171f87f0b5SEric W. Biederman static void unuse_table(struct ctl_table_header *p) 2181f87f0b5SEric W. Biederman { 2191f87f0b5SEric W. Biederman if (!--p->used) 2201f87f0b5SEric W. Biederman if (unlikely(p->unregistering)) 2211f87f0b5SEric W. Biederman complete(p->unregistering); 2221f87f0b5SEric W. Biederman } 2231f87f0b5SEric W. Biederman 2241f87f0b5SEric W. Biederman /* called under sysctl_lock, will reacquire if has to wait */ 2251f87f0b5SEric W. Biederman static void start_unregistering(struct ctl_table_header *p) 2261f87f0b5SEric W. Biederman { 2271f87f0b5SEric W. Biederman /* 2281f87f0b5SEric W. Biederman * if p->used is 0, nobody will ever touch that entry again; 2291f87f0b5SEric W. Biederman * we'll eliminate all paths to it before dropping sysctl_lock 2301f87f0b5SEric W. Biederman */ 2311f87f0b5SEric W. Biederman if (unlikely(p->used)) { 2321f87f0b5SEric W. Biederman struct completion wait; 2331f87f0b5SEric W. Biederman init_completion(&wait); 2341f87f0b5SEric W. Biederman p->unregistering = &wait; 2351f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2361f87f0b5SEric W. Biederman wait_for_completion(&wait); 2371f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 2381f87f0b5SEric W. Biederman } else { 2391f87f0b5SEric W. Biederman /* anything non-NULL; we'll never dereference it */ 2401f87f0b5SEric W. Biederman p->unregistering = ERR_PTR(-EINVAL); 2411f87f0b5SEric W. Biederman } 2421f87f0b5SEric W. Biederman /* 2431f87f0b5SEric W. Biederman * do not remove from the list until nobody holds it; walking the 2441f87f0b5SEric W. Biederman * list in do_sysctl() relies on that. 2451f87f0b5SEric W. Biederman */ 2468425d6aaSEric W. Biederman erase_header(p); 2471f87f0b5SEric W. Biederman } 2481f87f0b5SEric W. Biederman 2491f87f0b5SEric W. Biederman static void sysctl_head_get(struct ctl_table_header *head) 2501f87f0b5SEric W. Biederman { 2511f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 2521f87f0b5SEric W. Biederman head->count++; 2531f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2541f87f0b5SEric W. Biederman } 2551f87f0b5SEric W. Biederman 2561f87f0b5SEric W. Biederman void sysctl_head_put(struct ctl_table_header *head) 2571f87f0b5SEric W. Biederman { 2581f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 2591f87f0b5SEric W. Biederman if (!--head->count) 2601f87f0b5SEric W. Biederman kfree_rcu(head, rcu); 2611f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2621f87f0b5SEric W. Biederman } 2631f87f0b5SEric W. Biederman 2641f87f0b5SEric W. Biederman static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) 2651f87f0b5SEric W. Biederman { 2661f87f0b5SEric W. Biederman if (!head) 2671f87f0b5SEric W. Biederman BUG(); 2681f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 2691f87f0b5SEric W. Biederman if (!use_table(head)) 2701f87f0b5SEric W. Biederman head = ERR_PTR(-ENOENT); 2711f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2721f87f0b5SEric W. Biederman return head; 2731f87f0b5SEric W. Biederman } 2741f87f0b5SEric W. Biederman 2751f87f0b5SEric W. Biederman static void sysctl_head_finish(struct ctl_table_header *head) 2761f87f0b5SEric W. Biederman { 2771f87f0b5SEric W. Biederman if (!head) 2781f87f0b5SEric W. Biederman return; 2791f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 2801f87f0b5SEric W. Biederman unuse_table(head); 2811f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2821f87f0b5SEric W. Biederman } 2831f87f0b5SEric W. Biederman 2841f87f0b5SEric W. Biederman static struct ctl_table_set * 2851f87f0b5SEric W. Biederman lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces) 2861f87f0b5SEric W. Biederman { 2871f87f0b5SEric W. Biederman struct ctl_table_set *set = &root->default_set; 2881f87f0b5SEric W. Biederman if (root->lookup) 2891f87f0b5SEric W. Biederman set = root->lookup(root, namespaces); 2901f87f0b5SEric W. Biederman return set; 2911f87f0b5SEric W. Biederman } 2921f87f0b5SEric W. Biederman 293076c3eedSEric W. Biederman static struct ctl_table *lookup_entry(struct ctl_table_header **phead, 2947ec66d06SEric W. Biederman struct ctl_dir *dir, 295076c3eedSEric W. Biederman const char *name, int namelen) 296076c3eedSEric W. Biederman { 297076c3eedSEric W. Biederman struct ctl_table_header *head; 298076c3eedSEric W. Biederman struct ctl_table *entry; 299076c3eedSEric W. Biederman 300076c3eedSEric W. Biederman spin_lock(&sysctl_lock); 3010e47c99dSEric W. Biederman entry = find_entry(&head, dir, name, namelen); 302076c3eedSEric W. Biederman if (entry && use_table(head)) 303076c3eedSEric W. Biederman *phead = head; 304076c3eedSEric W. Biederman else 305076c3eedSEric W. Biederman entry = NULL; 306076c3eedSEric W. Biederman spin_unlock(&sysctl_lock); 307076c3eedSEric W. Biederman return entry; 308076c3eedSEric W. Biederman } 309076c3eedSEric W. Biederman 310*ac13ac6fSEric W. Biederman static struct ctl_node *first_usable_entry(struct rb_node *node) 3111f87f0b5SEric W. Biederman { 312*ac13ac6fSEric W. Biederman struct ctl_node *ctl_node; 3131f87f0b5SEric W. Biederman 314*ac13ac6fSEric W. Biederman for (;node; node = rb_next(node)) { 315*ac13ac6fSEric W. Biederman ctl_node = rb_entry(node, struct ctl_node, node); 316*ac13ac6fSEric W. Biederman if (use_table(ctl_node->header)) 317*ac13ac6fSEric W. Biederman return ctl_node; 3181f87f0b5SEric W. Biederman } 3191f87f0b5SEric W. Biederman return NULL; 3201f87f0b5SEric W. Biederman } 3211f87f0b5SEric W. Biederman 3227ec66d06SEric W. Biederman static void first_entry(struct ctl_dir *dir, 3236a75ce16SEric W. Biederman struct ctl_table_header **phead, struct ctl_table **pentry) 3241f87f0b5SEric W. Biederman { 325*ac13ac6fSEric W. Biederman struct ctl_table_header *head = NULL; 3267ec66d06SEric W. Biederman struct ctl_table *entry = NULL; 327*ac13ac6fSEric W. Biederman struct ctl_node *ctl_node; 3286a75ce16SEric W. Biederman 3296a75ce16SEric W. Biederman spin_lock(&sysctl_lock); 330*ac13ac6fSEric W. Biederman ctl_node = first_usable_entry(rb_first(&dir->root)); 3316a75ce16SEric W. Biederman spin_unlock(&sysctl_lock); 332*ac13ac6fSEric W. Biederman if (ctl_node) { 333*ac13ac6fSEric W. Biederman head = ctl_node->header; 334*ac13ac6fSEric W. Biederman entry = &head->ctl_table[ctl_node - head->node]; 335*ac13ac6fSEric W. Biederman } 3366a75ce16SEric W. Biederman *phead = head; 3376a75ce16SEric W. Biederman *pentry = entry; 3386a75ce16SEric W. Biederman } 3396a75ce16SEric W. Biederman 3407ec66d06SEric W. Biederman static void next_entry(struct ctl_table_header **phead, struct ctl_table **pentry) 3416a75ce16SEric W. Biederman { 3426a75ce16SEric W. Biederman struct ctl_table_header *head = *phead; 3436a75ce16SEric W. Biederman struct ctl_table *entry = *pentry; 344*ac13ac6fSEric W. Biederman struct ctl_node *ctl_node = &head->node[entry - head->ctl_table]; 3456a75ce16SEric W. Biederman 3466a75ce16SEric W. Biederman spin_lock(&sysctl_lock); 3476a75ce16SEric W. Biederman unuse_table(head); 348*ac13ac6fSEric W. Biederman 349*ac13ac6fSEric W. Biederman ctl_node = first_usable_entry(rb_next(&ctl_node->node)); 3506a75ce16SEric W. Biederman spin_unlock(&sysctl_lock); 351*ac13ac6fSEric W. Biederman head = NULL; 352*ac13ac6fSEric W. Biederman if (ctl_node) { 353*ac13ac6fSEric W. Biederman head = ctl_node->header; 354*ac13ac6fSEric W. Biederman entry = &head->ctl_table[ctl_node - head->node]; 3556a75ce16SEric W. Biederman } 3566a75ce16SEric W. Biederman *phead = head; 3576a75ce16SEric W. Biederman *pentry = entry; 3581f87f0b5SEric W. Biederman } 3591f87f0b5SEric W. Biederman 3601f87f0b5SEric W. Biederman void register_sysctl_root(struct ctl_table_root *root) 3611f87f0b5SEric W. Biederman { 3621f87f0b5SEric W. Biederman } 3631f87f0b5SEric W. Biederman 3641f87f0b5SEric W. Biederman /* 3651f87f0b5SEric W. Biederman * sysctl_perm does NOT grant the superuser all rights automatically, because 3661f87f0b5SEric W. Biederman * some sysctl variables are readonly even to root. 3671f87f0b5SEric W. Biederman */ 3681f87f0b5SEric W. Biederman 3691f87f0b5SEric W. Biederman static int test_perm(int mode, int op) 3701f87f0b5SEric W. Biederman { 3711f87f0b5SEric W. Biederman if (!current_euid()) 3721f87f0b5SEric W. Biederman mode >>= 6; 3731f87f0b5SEric W. Biederman else if (in_egroup_p(0)) 3741f87f0b5SEric W. Biederman mode >>= 3; 3751f87f0b5SEric W. Biederman if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) 3761f87f0b5SEric W. Biederman return 0; 3771f87f0b5SEric W. Biederman return -EACCES; 3781f87f0b5SEric W. Biederman } 3791f87f0b5SEric W. Biederman 3801f87f0b5SEric W. Biederman static int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op) 3811f87f0b5SEric W. Biederman { 3821f87f0b5SEric W. Biederman int mode; 3831f87f0b5SEric W. Biederman 3841f87f0b5SEric W. Biederman if (root->permissions) 3851f87f0b5SEric W. Biederman mode = root->permissions(root, current->nsproxy, table); 3861f87f0b5SEric W. Biederman else 3871f87f0b5SEric W. Biederman mode = table->mode; 3881f87f0b5SEric W. Biederman 3891f87f0b5SEric W. Biederman return test_perm(mode, op); 3901f87f0b5SEric W. Biederman } 3911f87f0b5SEric W. Biederman 3929043476fSAl Viro static struct inode *proc_sys_make_inode(struct super_block *sb, 3939043476fSAl Viro struct ctl_table_header *head, struct ctl_table *table) 39477b14db5SEric W. Biederman { 39577b14db5SEric W. Biederman struct inode *inode; 3969043476fSAl Viro struct proc_inode *ei; 39777b14db5SEric W. Biederman 3989043476fSAl Viro inode = new_inode(sb); 39977b14db5SEric W. Biederman if (!inode) 40077b14db5SEric W. Biederman goto out; 40177b14db5SEric W. Biederman 40285fe4025SChristoph Hellwig inode->i_ino = get_next_ino(); 40385fe4025SChristoph Hellwig 4049043476fSAl Viro sysctl_head_get(head); 40577b14db5SEric W. Biederman ei = PROC_I(inode); 4069043476fSAl Viro ei->sysctl = head; 4079043476fSAl Viro ei->sysctl_entry = table; 4089043476fSAl Viro 40977b14db5SEric W. Biederman inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 4109043476fSAl Viro inode->i_mode = table->mode; 4117ec66d06SEric W. Biederman if (!S_ISDIR(table->mode)) { 4129043476fSAl Viro inode->i_mode |= S_IFREG; 41377b14db5SEric W. Biederman inode->i_op = &proc_sys_inode_operations; 41477b14db5SEric W. Biederman inode->i_fop = &proc_sys_file_operations; 4159043476fSAl Viro } else { 4169043476fSAl Viro inode->i_mode |= S_IFDIR; 4179043476fSAl Viro inode->i_op = &proc_sys_dir_operations; 4189043476fSAl Viro inode->i_fop = &proc_sys_dir_file_operations; 4199043476fSAl Viro } 42077b14db5SEric W. Biederman out: 42177b14db5SEric W. Biederman return inode; 42277b14db5SEric W. Biederman } 42377b14db5SEric W. Biederman 42481324364SAdrian Bunk static struct ctl_table_header *grab_header(struct inode *inode) 42577b14db5SEric W. Biederman { 4263cc3e046SEric W. Biederman struct ctl_table_header *head = PROC_I(inode)->sysctl; 4273cc3e046SEric W. Biederman if (!head) 4280e47c99dSEric W. Biederman head = &sysctl_table_root.default_set.dir.header; 4293cc3e046SEric W. Biederman return sysctl_head_grab(head); 43077b14db5SEric W. Biederman } 43177b14db5SEric W. Biederman 43277b14db5SEric W. Biederman static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, 43377b14db5SEric W. Biederman struct nameidata *nd) 43477b14db5SEric W. Biederman { 4359043476fSAl Viro struct ctl_table_header *head = grab_header(dir); 4369043476fSAl Viro struct ctl_table_header *h = NULL; 4379043476fSAl Viro struct qstr *name = &dentry->d_name; 4389043476fSAl Viro struct ctl_table *p; 43977b14db5SEric W. Biederman struct inode *inode; 4409043476fSAl Viro struct dentry *err = ERR_PTR(-ENOENT); 4417ec66d06SEric W. Biederman struct ctl_dir *ctl_dir; 4420e47c99dSEric W. Biederman int ret; 44377b14db5SEric W. Biederman 4449043476fSAl Viro if (IS_ERR(head)) 4459043476fSAl Viro return ERR_CAST(head); 4469043476fSAl Viro 4477ec66d06SEric W. Biederman ctl_dir = container_of(head, struct ctl_dir, header); 4489043476fSAl Viro 4497ec66d06SEric W. Biederman p = lookup_entry(&h, ctl_dir, name->name, name->len); 4509043476fSAl Viro if (!p) 45177b14db5SEric W. Biederman goto out; 45277b14db5SEric W. Biederman 4530e47c99dSEric W. Biederman ret = sysctl_follow_link(&h, &p, current->nsproxy); 4540e47c99dSEric W. Biederman err = ERR_PTR(ret); 4550e47c99dSEric W. Biederman if (ret) 4560e47c99dSEric W. Biederman goto out; 4570e47c99dSEric W. Biederman 45877b14db5SEric W. Biederman err = ERR_PTR(-ENOMEM); 4599043476fSAl Viro inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); 4609043476fSAl Viro if (h) 4619043476fSAl Viro sysctl_head_finish(h); 4629043476fSAl Viro 46377b14db5SEric W. Biederman if (!inode) 46477b14db5SEric W. Biederman goto out; 46577b14db5SEric W. Biederman 46677b14db5SEric W. Biederman err = NULL; 467fb045adbSNick Piggin d_set_d_op(dentry, &proc_sys_dentry_operations); 46877b14db5SEric W. Biederman d_add(dentry, inode); 46977b14db5SEric W. Biederman 47077b14db5SEric W. Biederman out: 47177b14db5SEric W. Biederman sysctl_head_finish(head); 47277b14db5SEric W. Biederman return err; 47377b14db5SEric W. Biederman } 47477b14db5SEric W. Biederman 4757708bfb1SPavel Emelyanov static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf, 4767708bfb1SPavel Emelyanov size_t count, loff_t *ppos, int write) 47777b14db5SEric W. Biederman { 4789043476fSAl Viro struct inode *inode = filp->f_path.dentry->d_inode; 4799043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 4809043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 4812a2da53bSDavid Howells ssize_t error; 4822a2da53bSDavid Howells size_t res; 48377b14db5SEric W. Biederman 4849043476fSAl Viro if (IS_ERR(head)) 4859043476fSAl Viro return PTR_ERR(head); 48677b14db5SEric W. Biederman 48777b14db5SEric W. Biederman /* 48877b14db5SEric W. Biederman * At this point we know that the sysctl was not unregistered 48977b14db5SEric W. Biederman * and won't be until we finish. 49077b14db5SEric W. Biederman */ 49177b14db5SEric W. Biederman error = -EPERM; 492d7321cd6SPavel Emelyanov if (sysctl_perm(head->root, table, write ? MAY_WRITE : MAY_READ)) 49377b14db5SEric W. Biederman goto out; 49477b14db5SEric W. Biederman 4959043476fSAl Viro /* if that can happen at all, it should be -EINVAL, not -EISDIR */ 4969043476fSAl Viro error = -EINVAL; 4979043476fSAl Viro if (!table->proc_handler) 4989043476fSAl Viro goto out; 4999043476fSAl Viro 50077b14db5SEric W. Biederman /* careful: calling conventions are nasty here */ 50177b14db5SEric W. Biederman res = count; 5028d65af78SAlexey Dobriyan error = table->proc_handler(table, write, buf, &res, ppos); 50377b14db5SEric W. Biederman if (!error) 50477b14db5SEric W. Biederman error = res; 50577b14db5SEric W. Biederman out: 50677b14db5SEric W. Biederman sysctl_head_finish(head); 50777b14db5SEric W. Biederman 50877b14db5SEric W. Biederman return error; 50977b14db5SEric W. Biederman } 51077b14db5SEric W. Biederman 5117708bfb1SPavel Emelyanov static ssize_t proc_sys_read(struct file *filp, char __user *buf, 5127708bfb1SPavel Emelyanov size_t count, loff_t *ppos) 5137708bfb1SPavel Emelyanov { 5147708bfb1SPavel Emelyanov return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0); 5157708bfb1SPavel Emelyanov } 5167708bfb1SPavel Emelyanov 51777b14db5SEric W. Biederman static ssize_t proc_sys_write(struct file *filp, const char __user *buf, 51877b14db5SEric W. Biederman size_t count, loff_t *ppos) 51977b14db5SEric W. Biederman { 5207708bfb1SPavel Emelyanov return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1); 52177b14db5SEric W. Biederman } 52277b14db5SEric W. Biederman 523f1ecf068SLucas De Marchi static int proc_sys_open(struct inode *inode, struct file *filp) 524f1ecf068SLucas De Marchi { 525f1ecf068SLucas De Marchi struct ctl_table *table = PROC_I(inode)->sysctl_entry; 526f1ecf068SLucas De Marchi 527f1ecf068SLucas De Marchi if (table->poll) 528f1ecf068SLucas De Marchi filp->private_data = proc_sys_poll_event(table->poll); 529f1ecf068SLucas De Marchi 530f1ecf068SLucas De Marchi return 0; 531f1ecf068SLucas De Marchi } 532f1ecf068SLucas De Marchi 533f1ecf068SLucas De Marchi static unsigned int proc_sys_poll(struct file *filp, poll_table *wait) 534f1ecf068SLucas De Marchi { 535f1ecf068SLucas De Marchi struct inode *inode = filp->f_path.dentry->d_inode; 536f1ecf068SLucas De Marchi struct ctl_table *table = PROC_I(inode)->sysctl_entry; 537f1ecf068SLucas De Marchi unsigned long event = (unsigned long)filp->private_data; 538f1ecf068SLucas De Marchi unsigned int ret = DEFAULT_POLLMASK; 539f1ecf068SLucas De Marchi 540f1ecf068SLucas De Marchi if (!table->proc_handler) 541f1ecf068SLucas De Marchi goto out; 542f1ecf068SLucas De Marchi 543f1ecf068SLucas De Marchi if (!table->poll) 544f1ecf068SLucas De Marchi goto out; 545f1ecf068SLucas De Marchi 546f1ecf068SLucas De Marchi poll_wait(filp, &table->poll->wait, wait); 547f1ecf068SLucas De Marchi 548f1ecf068SLucas De Marchi if (event != atomic_read(&table->poll->event)) { 549f1ecf068SLucas De Marchi filp->private_data = proc_sys_poll_event(table->poll); 550f1ecf068SLucas De Marchi ret = POLLIN | POLLRDNORM | POLLERR | POLLPRI; 551f1ecf068SLucas De Marchi } 552f1ecf068SLucas De Marchi 553f1ecf068SLucas De Marchi out: 554f1ecf068SLucas De Marchi return ret; 555f1ecf068SLucas De Marchi } 55677b14db5SEric W. Biederman 55777b14db5SEric W. Biederman static int proc_sys_fill_cache(struct file *filp, void *dirent, 5589043476fSAl Viro filldir_t filldir, 5599043476fSAl Viro struct ctl_table_header *head, 5609043476fSAl Viro struct ctl_table *table) 56177b14db5SEric W. Biederman { 56277b14db5SEric W. Biederman struct dentry *child, *dir = filp->f_path.dentry; 56377b14db5SEric W. Biederman struct inode *inode; 56477b14db5SEric W. Biederman struct qstr qname; 56577b14db5SEric W. Biederman ino_t ino = 0; 56677b14db5SEric W. Biederman unsigned type = DT_UNKNOWN; 56777b14db5SEric W. Biederman 56877b14db5SEric W. Biederman qname.name = table->procname; 56977b14db5SEric W. Biederman qname.len = strlen(table->procname); 57077b14db5SEric W. Biederman qname.hash = full_name_hash(qname.name, qname.len); 57177b14db5SEric W. Biederman 57277b14db5SEric W. Biederman child = d_lookup(dir, &qname); 57377b14db5SEric W. Biederman if (!child) { 5749043476fSAl Viro child = d_alloc(dir, &qname); 5759043476fSAl Viro if (child) { 5769043476fSAl Viro inode = proc_sys_make_inode(dir->d_sb, head, table); 5779043476fSAl Viro if (!inode) { 5789043476fSAl Viro dput(child); 5799043476fSAl Viro return -ENOMEM; 5809043476fSAl Viro } else { 581fb045adbSNick Piggin d_set_d_op(child, &proc_sys_dentry_operations); 5829043476fSAl Viro d_add(child, inode); 58377b14db5SEric W. Biederman } 5849043476fSAl Viro } else { 5859043476fSAl Viro return -ENOMEM; 58677b14db5SEric W. Biederman } 58777b14db5SEric W. Biederman } 58877b14db5SEric W. Biederman inode = child->d_inode; 58977b14db5SEric W. Biederman ino = inode->i_ino; 59077b14db5SEric W. Biederman type = inode->i_mode >> 12; 59177b14db5SEric W. Biederman dput(child); 5929043476fSAl Viro return !!filldir(dirent, qname.name, qname.len, filp->f_pos, ino, type); 5939043476fSAl Viro } 5949043476fSAl Viro 5950e47c99dSEric W. Biederman static int proc_sys_link_fill_cache(struct file *filp, void *dirent, 5960e47c99dSEric W. Biederman filldir_t filldir, 5970e47c99dSEric W. Biederman struct ctl_table_header *head, 5980e47c99dSEric W. Biederman struct ctl_table *table) 5990e47c99dSEric W. Biederman { 6000e47c99dSEric W. Biederman int err, ret = 0; 6010e47c99dSEric W. Biederman head = sysctl_head_grab(head); 6020e47c99dSEric W. Biederman 6030e47c99dSEric W. Biederman /* It is not an error if we can not follow the link ignore it */ 6040e47c99dSEric W. Biederman err = sysctl_follow_link(&head, &table, current->nsproxy); 6050e47c99dSEric W. Biederman if (err) 6060e47c99dSEric W. Biederman goto out; 6070e47c99dSEric W. Biederman 6080e47c99dSEric W. Biederman ret = proc_sys_fill_cache(filp, dirent, filldir, head, table); 6090e47c99dSEric W. Biederman out: 6100e47c99dSEric W. Biederman sysctl_head_finish(head); 6110e47c99dSEric W. Biederman return ret; 6120e47c99dSEric W. Biederman } 6130e47c99dSEric W. Biederman 6149043476fSAl Viro static int scan(struct ctl_table_header *head, ctl_table *table, 6159043476fSAl Viro unsigned long *pos, struct file *file, 6169043476fSAl Viro void *dirent, filldir_t filldir) 6179043476fSAl Viro { 6189043476fSAl Viro int res; 6199043476fSAl Viro 6206a75ce16SEric W. Biederman if ((*pos)++ < file->f_pos) 6216a75ce16SEric W. Biederman return 0; 6229043476fSAl Viro 6230e47c99dSEric W. Biederman if (unlikely(S_ISLNK(table->mode))) 6240e47c99dSEric W. Biederman res = proc_sys_link_fill_cache(file, dirent, filldir, head, table); 6250e47c99dSEric W. Biederman else 6269043476fSAl Viro res = proc_sys_fill_cache(file, dirent, filldir, head, table); 6279043476fSAl Viro 6286a75ce16SEric W. Biederman if (res == 0) 6296a75ce16SEric W. Biederman file->f_pos = *pos; 6306a75ce16SEric W. Biederman 6316a75ce16SEric W. Biederman return res; 63277b14db5SEric W. Biederman } 63377b14db5SEric W. Biederman 63477b14db5SEric W. Biederman static int proc_sys_readdir(struct file *filp, void *dirent, filldir_t filldir) 63577b14db5SEric W. Biederman { 6369043476fSAl Viro struct dentry *dentry = filp->f_path.dentry; 63777b14db5SEric W. Biederman struct inode *inode = dentry->d_inode; 6389043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 6399043476fSAl Viro struct ctl_table_header *h = NULL; 6406a75ce16SEric W. Biederman struct ctl_table *entry; 6417ec66d06SEric W. Biederman struct ctl_dir *ctl_dir; 64277b14db5SEric W. Biederman unsigned long pos; 6439043476fSAl Viro int ret = -EINVAL; 64477b14db5SEric W. Biederman 6459043476fSAl Viro if (IS_ERR(head)) 6469043476fSAl Viro return PTR_ERR(head); 6479043476fSAl Viro 6487ec66d06SEric W. Biederman ctl_dir = container_of(head, struct ctl_dir, header); 64977b14db5SEric W. Biederman 65077b14db5SEric W. Biederman ret = 0; 65177b14db5SEric W. Biederman /* Avoid a switch here: arm builds fail with missing __cmpdi2 */ 65277b14db5SEric W. Biederman if (filp->f_pos == 0) { 65377b14db5SEric W. Biederman if (filldir(dirent, ".", 1, filp->f_pos, 65477b14db5SEric W. Biederman inode->i_ino, DT_DIR) < 0) 65577b14db5SEric W. Biederman goto out; 65677b14db5SEric W. Biederman filp->f_pos++; 65777b14db5SEric W. Biederman } 65877b14db5SEric W. Biederman if (filp->f_pos == 1) { 65977b14db5SEric W. Biederman if (filldir(dirent, "..", 2, filp->f_pos, 66077b14db5SEric W. Biederman parent_ino(dentry), DT_DIR) < 0) 66177b14db5SEric W. Biederman goto out; 66277b14db5SEric W. Biederman filp->f_pos++; 66377b14db5SEric W. Biederman } 66477b14db5SEric W. Biederman pos = 2; 66577b14db5SEric W. Biederman 6667ec66d06SEric W. Biederman for (first_entry(ctl_dir, &h, &entry); h; next_entry(&h, &entry)) { 6676a75ce16SEric W. Biederman ret = scan(h, entry, &pos, filp, dirent, filldir); 6689043476fSAl Viro if (ret) { 6699043476fSAl Viro sysctl_head_finish(h); 6709043476fSAl Viro break; 67177b14db5SEric W. Biederman } 67277b14db5SEric W. Biederman } 67377b14db5SEric W. Biederman ret = 1; 67477b14db5SEric W. Biederman out: 67577b14db5SEric W. Biederman sysctl_head_finish(head); 67677b14db5SEric W. Biederman return ret; 67777b14db5SEric W. Biederman } 67877b14db5SEric W. Biederman 67910556cb2SAl Viro static int proc_sys_permission(struct inode *inode, int mask) 68077b14db5SEric W. Biederman { 68177b14db5SEric W. Biederman /* 68277b14db5SEric W. Biederman * sysctl entries that are not writeable, 68377b14db5SEric W. Biederman * are _NOT_ writeable, capabilities or not. 68477b14db5SEric W. Biederman */ 685f696a365SMiklos Szeredi struct ctl_table_header *head; 686f696a365SMiklos Szeredi struct ctl_table *table; 68777b14db5SEric W. Biederman int error; 68877b14db5SEric W. Biederman 689f696a365SMiklos Szeredi /* Executable files are not allowed under /proc/sys/ */ 690f696a365SMiklos Szeredi if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) 691f696a365SMiklos Szeredi return -EACCES; 692f696a365SMiklos Szeredi 693f696a365SMiklos Szeredi head = grab_header(inode); 6949043476fSAl Viro if (IS_ERR(head)) 6959043476fSAl Viro return PTR_ERR(head); 69677b14db5SEric W. Biederman 697f696a365SMiklos Szeredi table = PROC_I(inode)->sysctl_entry; 6989043476fSAl Viro if (!table) /* global root - r-xr-xr-x */ 6999043476fSAl Viro error = mask & MAY_WRITE ? -EACCES : 0; 7009043476fSAl Viro else /* Use the permissions on the sysctl table entry */ 7011fc0f78cSAl Viro error = sysctl_perm(head->root, table, mask & ~MAY_NOT_BLOCK); 7029043476fSAl Viro 70377b14db5SEric W. Biederman sysctl_head_finish(head); 70477b14db5SEric W. Biederman return error; 70577b14db5SEric W. Biederman } 70677b14db5SEric W. Biederman 70777b14db5SEric W. Biederman static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr) 70877b14db5SEric W. Biederman { 70977b14db5SEric W. Biederman struct inode *inode = dentry->d_inode; 71077b14db5SEric W. Biederman int error; 71177b14db5SEric W. Biederman 71277b14db5SEric W. Biederman if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) 71377b14db5SEric W. Biederman return -EPERM; 71477b14db5SEric W. Biederman 71577b14db5SEric W. Biederman error = inode_change_ok(inode, attr); 7161025774cSChristoph Hellwig if (error) 71777b14db5SEric W. Biederman return error; 7181025774cSChristoph Hellwig 7191025774cSChristoph Hellwig if ((attr->ia_valid & ATTR_SIZE) && 7201025774cSChristoph Hellwig attr->ia_size != i_size_read(inode)) { 7211025774cSChristoph Hellwig error = vmtruncate(inode, attr->ia_size); 7221025774cSChristoph Hellwig if (error) 7231025774cSChristoph Hellwig return error; 7241025774cSChristoph Hellwig } 7251025774cSChristoph Hellwig 7261025774cSChristoph Hellwig setattr_copy(inode, attr); 7271025774cSChristoph Hellwig mark_inode_dirty(inode); 7281025774cSChristoph Hellwig return 0; 72977b14db5SEric W. Biederman } 73077b14db5SEric W. Biederman 7319043476fSAl Viro static int proc_sys_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 7329043476fSAl Viro { 7339043476fSAl Viro struct inode *inode = dentry->d_inode; 7349043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 7359043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 7369043476fSAl Viro 7379043476fSAl Viro if (IS_ERR(head)) 7389043476fSAl Viro return PTR_ERR(head); 7399043476fSAl Viro 7409043476fSAl Viro generic_fillattr(inode, stat); 7419043476fSAl Viro if (table) 7429043476fSAl Viro stat->mode = (stat->mode & S_IFMT) | table->mode; 7439043476fSAl Viro 7449043476fSAl Viro sysctl_head_finish(head); 7459043476fSAl Viro return 0; 7469043476fSAl Viro } 7479043476fSAl Viro 74877b14db5SEric W. Biederman static const struct file_operations proc_sys_file_operations = { 749f1ecf068SLucas De Marchi .open = proc_sys_open, 750f1ecf068SLucas De Marchi .poll = proc_sys_poll, 75177b14db5SEric W. Biederman .read = proc_sys_read, 75277b14db5SEric W. Biederman .write = proc_sys_write, 7536038f373SArnd Bergmann .llseek = default_llseek, 7549043476fSAl Viro }; 7559043476fSAl Viro 7569043476fSAl Viro static const struct file_operations proc_sys_dir_file_operations = { 757887df078SPavel Emelyanov .read = generic_read_dir, 75877b14db5SEric W. Biederman .readdir = proc_sys_readdir, 7593222a3e5SChristoph Hellwig .llseek = generic_file_llseek, 76077b14db5SEric W. Biederman }; 76177b14db5SEric W. Biederman 76203a44825SJan Engelhardt static const struct inode_operations proc_sys_inode_operations = { 7639043476fSAl Viro .permission = proc_sys_permission, 7649043476fSAl Viro .setattr = proc_sys_setattr, 7659043476fSAl Viro .getattr = proc_sys_getattr, 7669043476fSAl Viro }; 7679043476fSAl Viro 7689043476fSAl Viro static const struct inode_operations proc_sys_dir_operations = { 76977b14db5SEric W. Biederman .lookup = proc_sys_lookup, 77077b14db5SEric W. Biederman .permission = proc_sys_permission, 77177b14db5SEric W. Biederman .setattr = proc_sys_setattr, 7729043476fSAl Viro .getattr = proc_sys_getattr, 77377b14db5SEric W. Biederman }; 77477b14db5SEric W. Biederman 77577b14db5SEric W. Biederman static int proc_sys_revalidate(struct dentry *dentry, struct nameidata *nd) 77677b14db5SEric W. Biederman { 77734286d66SNick Piggin if (nd->flags & LOOKUP_RCU) 77834286d66SNick Piggin return -ECHILD; 7799043476fSAl Viro return !PROC_I(dentry->d_inode)->sysctl->unregistering; 7809043476fSAl Viro } 7819043476fSAl Viro 782fe15ce44SNick Piggin static int proc_sys_delete(const struct dentry *dentry) 7839043476fSAl Viro { 7849043476fSAl Viro return !!PROC_I(dentry->d_inode)->sysctl->unregistering; 7859043476fSAl Viro } 7869043476fSAl Viro 7871f87f0b5SEric W. Biederman static int sysctl_is_seen(struct ctl_table_header *p) 7881f87f0b5SEric W. Biederman { 7891f87f0b5SEric W. Biederman struct ctl_table_set *set = p->set; 7901f87f0b5SEric W. Biederman int res; 7911f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 7921f87f0b5SEric W. Biederman if (p->unregistering) 7931f87f0b5SEric W. Biederman res = 0; 7941f87f0b5SEric W. Biederman else if (!set->is_seen) 7951f87f0b5SEric W. Biederman res = 1; 7961f87f0b5SEric W. Biederman else 7971f87f0b5SEric W. Biederman res = set->is_seen(set); 7981f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 7991f87f0b5SEric W. Biederman return res; 8001f87f0b5SEric W. Biederman } 8011f87f0b5SEric W. Biederman 802621e155aSNick Piggin static int proc_sys_compare(const struct dentry *parent, 803621e155aSNick Piggin const struct inode *pinode, 804621e155aSNick Piggin const struct dentry *dentry, const struct inode *inode, 805621e155aSNick Piggin unsigned int len, const char *str, const struct qstr *name) 8069043476fSAl Viro { 807dfef6dcdSAl Viro struct ctl_table_header *head; 80831e6b01fSNick Piggin /* Although proc doesn't have negative dentries, rcu-walk means 80931e6b01fSNick Piggin * that inode here can be NULL */ 810dfef6dcdSAl Viro /* AV: can it, indeed? */ 81131e6b01fSNick Piggin if (!inode) 812dfef6dcdSAl Viro return 1; 813621e155aSNick Piggin if (name->len != len) 8149043476fSAl Viro return 1; 815621e155aSNick Piggin if (memcmp(name->name, str, len)) 8169043476fSAl Viro return 1; 817dfef6dcdSAl Viro head = rcu_dereference(PROC_I(inode)->sysctl); 818dfef6dcdSAl Viro return !head || !sysctl_is_seen(head); 81977b14db5SEric W. Biederman } 82077b14db5SEric W. Biederman 821d72f71ebSAl Viro static const struct dentry_operations proc_sys_dentry_operations = { 82277b14db5SEric W. Biederman .d_revalidate = proc_sys_revalidate, 8239043476fSAl Viro .d_delete = proc_sys_delete, 8249043476fSAl Viro .d_compare = proc_sys_compare, 82577b14db5SEric W. Biederman }; 82677b14db5SEric W. Biederman 8270e47c99dSEric W. Biederman static struct ctl_dir *find_subdir(struct ctl_dir *dir, 8287ec66d06SEric W. Biederman const char *name, int namelen) 8291f87f0b5SEric W. Biederman { 8307ec66d06SEric W. Biederman struct ctl_table_header *head; 8317ec66d06SEric W. Biederman struct ctl_table *entry; 8321f87f0b5SEric W. Biederman 8330e47c99dSEric W. Biederman entry = find_entry(&head, dir, name, namelen); 8347ec66d06SEric W. Biederman if (!entry) 8357ec66d06SEric W. Biederman return ERR_PTR(-ENOENT); 8367ec66d06SEric W. Biederman if (S_ISDIR(entry->mode)) 8377ec66d06SEric W. Biederman return container_of(head, struct ctl_dir, header); 8387ec66d06SEric W. Biederman return ERR_PTR(-ENOTDIR); 8391f87f0b5SEric W. Biederman } 8401f87f0b5SEric W. Biederman 8417ec66d06SEric W. Biederman static struct ctl_dir *new_dir(struct ctl_table_set *set, 8427ec66d06SEric W. Biederman const char *name, int namelen) 8431f87f0b5SEric W. Biederman { 8447ec66d06SEric W. Biederman struct ctl_table *table; 8457ec66d06SEric W. Biederman struct ctl_dir *new; 846*ac13ac6fSEric W. Biederman struct ctl_node *node; 8477ec66d06SEric W. Biederman char *new_name; 8481f87f0b5SEric W. Biederman 849*ac13ac6fSEric W. Biederman new = kzalloc(sizeof(*new) + sizeof(struct ctl_node) + 850*ac13ac6fSEric W. Biederman sizeof(struct ctl_table)*2 + namelen + 1, 851*ac13ac6fSEric W. Biederman GFP_KERNEL); 8527ec66d06SEric W. Biederman if (!new) 8537ec66d06SEric W. Biederman return NULL; 8547ec66d06SEric W. Biederman 855*ac13ac6fSEric W. Biederman node = (struct ctl_node *)(new + 1); 856*ac13ac6fSEric W. Biederman table = (struct ctl_table *)(node + 1); 8577ec66d06SEric W. Biederman new_name = (char *)(table + 2); 8587ec66d06SEric W. Biederman memcpy(new_name, name, namelen); 8597ec66d06SEric W. Biederman new_name[namelen] = '\0'; 8607ec66d06SEric W. Biederman table[0].procname = new_name; 8617ec66d06SEric W. Biederman table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO; 862*ac13ac6fSEric W. Biederman init_header(&new->header, set->dir.header.root, set, node, table); 8637ec66d06SEric W. Biederman 8647ec66d06SEric W. Biederman return new; 8651f87f0b5SEric W. Biederman } 8661f87f0b5SEric W. Biederman 8670e47c99dSEric W. Biederman static struct ctl_dir *get_subdir(struct ctl_dir *dir, 8680e47c99dSEric W. Biederman const char *name, int namelen) 8697ec66d06SEric W. Biederman { 8700e47c99dSEric W. Biederman struct ctl_table_set *set = dir->header.set; 8717ec66d06SEric W. Biederman struct ctl_dir *subdir, *new = NULL; 8727ec66d06SEric W. Biederman 8737ec66d06SEric W. Biederman spin_lock(&sysctl_lock); 8740e47c99dSEric W. Biederman subdir = find_subdir(dir, name, namelen); 8757ec66d06SEric W. Biederman if (!IS_ERR(subdir)) 8767ec66d06SEric W. Biederman goto found; 8777ec66d06SEric W. Biederman if (PTR_ERR(subdir) != -ENOENT) 8787ec66d06SEric W. Biederman goto failed; 8797ec66d06SEric W. Biederman 8807ec66d06SEric W. Biederman spin_unlock(&sysctl_lock); 8817ec66d06SEric W. Biederman new = new_dir(set, name, namelen); 8827ec66d06SEric W. Biederman spin_lock(&sysctl_lock); 8837ec66d06SEric W. Biederman subdir = ERR_PTR(-ENOMEM); 8847ec66d06SEric W. Biederman if (!new) 8857ec66d06SEric W. Biederman goto failed; 8867ec66d06SEric W. Biederman 8870e47c99dSEric W. Biederman subdir = find_subdir(dir, name, namelen); 8887ec66d06SEric W. Biederman if (!IS_ERR(subdir)) 8897ec66d06SEric W. Biederman goto found; 8907ec66d06SEric W. Biederman if (PTR_ERR(subdir) != -ENOENT) 8917ec66d06SEric W. Biederman goto failed; 8927ec66d06SEric W. Biederman 8930e47c99dSEric W. Biederman if (insert_header(dir, &new->header)) 8940e47c99dSEric W. Biederman goto failed; 8957ec66d06SEric W. Biederman subdir = new; 8967ec66d06SEric W. Biederman found: 8977ec66d06SEric W. Biederman subdir->header.nreg++; 8987ec66d06SEric W. Biederman failed: 8997ec66d06SEric W. Biederman if (unlikely(IS_ERR(subdir))) { 9006980128fSEric W. Biederman printk(KERN_ERR "sysctl could not get directory: "); 9016980128fSEric W. Biederman sysctl_print_dir(dir); 9026980128fSEric W. Biederman printk(KERN_CONT "/%*.*s %ld\n", 9037ec66d06SEric W. Biederman namelen, namelen, name, PTR_ERR(subdir)); 9041f87f0b5SEric W. Biederman } 9057ec66d06SEric W. Biederman drop_sysctl_table(&dir->header); 9067ec66d06SEric W. Biederman if (new) 9077ec66d06SEric W. Biederman drop_sysctl_table(&new->header); 9087ec66d06SEric W. Biederman spin_unlock(&sysctl_lock); 9097ec66d06SEric W. Biederman return subdir; 9101f87f0b5SEric W. Biederman } 9111f87f0b5SEric W. Biederman 9120e47c99dSEric W. Biederman static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir) 9130e47c99dSEric W. Biederman { 9140e47c99dSEric W. Biederman struct ctl_dir *parent; 9150e47c99dSEric W. Biederman const char *procname; 9160e47c99dSEric W. Biederman if (!dir->header.parent) 9170e47c99dSEric W. Biederman return &set->dir; 9180e47c99dSEric W. Biederman parent = xlate_dir(set, dir->header.parent); 9190e47c99dSEric W. Biederman if (IS_ERR(parent)) 9200e47c99dSEric W. Biederman return parent; 9210e47c99dSEric W. Biederman procname = dir->header.ctl_table[0].procname; 9220e47c99dSEric W. Biederman return find_subdir(parent, procname, strlen(procname)); 9230e47c99dSEric W. Biederman } 9240e47c99dSEric W. Biederman 9250e47c99dSEric W. Biederman static int sysctl_follow_link(struct ctl_table_header **phead, 9260e47c99dSEric W. Biederman struct ctl_table **pentry, struct nsproxy *namespaces) 9270e47c99dSEric W. Biederman { 9280e47c99dSEric W. Biederman struct ctl_table_header *head; 9290e47c99dSEric W. Biederman struct ctl_table_root *root; 9300e47c99dSEric W. Biederman struct ctl_table_set *set; 9310e47c99dSEric W. Biederman struct ctl_table *entry; 9320e47c99dSEric W. Biederman struct ctl_dir *dir; 9330e47c99dSEric W. Biederman int ret; 9340e47c99dSEric W. Biederman 9350e47c99dSEric W. Biederman /* Get out quickly if not a link */ 9360e47c99dSEric W. Biederman if (!S_ISLNK((*pentry)->mode)) 9370e47c99dSEric W. Biederman return 0; 9380e47c99dSEric W. Biederman 9390e47c99dSEric W. Biederman ret = 0; 9400e47c99dSEric W. Biederman spin_lock(&sysctl_lock); 9410e47c99dSEric W. Biederman root = (*pentry)->data; 9420e47c99dSEric W. Biederman set = lookup_header_set(root, namespaces); 9430e47c99dSEric W. Biederman dir = xlate_dir(set, (*phead)->parent); 9440e47c99dSEric W. Biederman if (IS_ERR(dir)) 9450e47c99dSEric W. Biederman ret = PTR_ERR(dir); 9460e47c99dSEric W. Biederman else { 9470e47c99dSEric W. Biederman const char *procname = (*pentry)->procname; 9480e47c99dSEric W. Biederman head = NULL; 9490e47c99dSEric W. Biederman entry = find_entry(&head, dir, procname, strlen(procname)); 9500e47c99dSEric W. Biederman ret = -ENOENT; 9510e47c99dSEric W. Biederman if (entry && use_table(head)) { 9520e47c99dSEric W. Biederman unuse_table(*phead); 9530e47c99dSEric W. Biederman *phead = head; 9540e47c99dSEric W. Biederman *pentry = entry; 9550e47c99dSEric W. Biederman ret = 0; 9560e47c99dSEric W. Biederman } 9570e47c99dSEric W. Biederman } 9580e47c99dSEric W. Biederman 9590e47c99dSEric W. Biederman spin_unlock(&sysctl_lock); 9600e47c99dSEric W. Biederman return ret; 9610e47c99dSEric W. Biederman } 9620e47c99dSEric W. Biederman 9637c60c48fSEric W. Biederman static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...) 9647c60c48fSEric W. Biederman { 9657c60c48fSEric W. Biederman struct va_format vaf; 9667c60c48fSEric W. Biederman va_list args; 9677c60c48fSEric W. Biederman 9687c60c48fSEric W. Biederman va_start(args, fmt); 9697c60c48fSEric W. Biederman vaf.fmt = fmt; 9707c60c48fSEric W. Biederman vaf.va = &args; 9717c60c48fSEric W. Biederman 9727c60c48fSEric W. Biederman printk(KERN_ERR "sysctl table check failed: %s/%s %pV\n", 9737c60c48fSEric W. Biederman path, table->procname, &vaf); 9747c60c48fSEric W. Biederman 9757c60c48fSEric W. Biederman va_end(args); 9767c60c48fSEric W. Biederman return -EINVAL; 9777c60c48fSEric W. Biederman } 9787c60c48fSEric W. Biederman 9797c60c48fSEric W. Biederman static int sysctl_check_table(const char *path, struct ctl_table *table) 9807c60c48fSEric W. Biederman { 9817c60c48fSEric W. Biederman int err = 0; 9827c60c48fSEric W. Biederman for (; table->procname; table++) { 9837c60c48fSEric W. Biederman if (table->child) 9847c60c48fSEric W. Biederman err = sysctl_err(path, table, "Not a file"); 9857c60c48fSEric W. Biederman 9861f87f0b5SEric W. Biederman if ((table->proc_handler == proc_dostring) || 9871f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec) || 9881f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_minmax) || 9891f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_jiffies) || 9901f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_userhz_jiffies) || 9911f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_ms_jiffies) || 9921f87f0b5SEric W. Biederman (table->proc_handler == proc_doulongvec_minmax) || 9931f87f0b5SEric W. Biederman (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) { 9941f87f0b5SEric W. Biederman if (!table->data) 9957c60c48fSEric W. Biederman err = sysctl_err(path, table, "No data"); 9961f87f0b5SEric W. Biederman if (!table->maxlen) 9977c60c48fSEric W. Biederman err = sysctl_err(path, table, "No maxlen"); 9981f87f0b5SEric W. Biederman } 9991f87f0b5SEric W. Biederman if (!table->proc_handler) 10007c60c48fSEric W. Biederman err = sysctl_err(path, table, "No proc_handler"); 10017c60c48fSEric W. Biederman 10027c60c48fSEric W. Biederman if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode) 10037c60c48fSEric W. Biederman err = sysctl_err(path, table, "bogus .mode 0%o", 10047c60c48fSEric W. Biederman table->mode); 10051f87f0b5SEric W. Biederman } 10067c60c48fSEric W. Biederman return err; 10071f87f0b5SEric W. Biederman } 10081f87f0b5SEric W. Biederman 10090e47c99dSEric W. Biederman static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table *table, 10100e47c99dSEric W. Biederman struct ctl_table_root *link_root) 10110e47c99dSEric W. Biederman { 10120e47c99dSEric W. Biederman struct ctl_table *link_table, *entry, *link; 10130e47c99dSEric W. Biederman struct ctl_table_header *links; 1014*ac13ac6fSEric W. Biederman struct ctl_node *node; 10150e47c99dSEric W. Biederman char *link_name; 10160e47c99dSEric W. Biederman int nr_entries, name_bytes; 10170e47c99dSEric W. Biederman 10180e47c99dSEric W. Biederman name_bytes = 0; 10190e47c99dSEric W. Biederman nr_entries = 0; 10200e47c99dSEric W. Biederman for (entry = table; entry->procname; entry++) { 10210e47c99dSEric W. Biederman nr_entries++; 10220e47c99dSEric W. Biederman name_bytes += strlen(entry->procname) + 1; 10230e47c99dSEric W. Biederman } 10240e47c99dSEric W. Biederman 10250e47c99dSEric W. Biederman links = kzalloc(sizeof(struct ctl_table_header) + 1026*ac13ac6fSEric W. Biederman sizeof(struct ctl_node)*nr_entries + 10270e47c99dSEric W. Biederman sizeof(struct ctl_table)*(nr_entries + 1) + 10280e47c99dSEric W. Biederman name_bytes, 10290e47c99dSEric W. Biederman GFP_KERNEL); 10300e47c99dSEric W. Biederman 10310e47c99dSEric W. Biederman if (!links) 10320e47c99dSEric W. Biederman return NULL; 10330e47c99dSEric W. Biederman 1034*ac13ac6fSEric W. Biederman node = (struct ctl_node *)(links + 1); 1035*ac13ac6fSEric W. Biederman link_table = (struct ctl_table *)(node + nr_entries); 10360e47c99dSEric W. Biederman link_name = (char *)&link_table[nr_entries + 1]; 10370e47c99dSEric W. Biederman 10380e47c99dSEric W. Biederman for (link = link_table, entry = table; entry->procname; link++, entry++) { 10390e47c99dSEric W. Biederman int len = strlen(entry->procname) + 1; 10400e47c99dSEric W. Biederman memcpy(link_name, entry->procname, len); 10410e47c99dSEric W. Biederman link->procname = link_name; 10420e47c99dSEric W. Biederman link->mode = S_IFLNK|S_IRWXUGO; 10430e47c99dSEric W. Biederman link->data = link_root; 10440e47c99dSEric W. Biederman link_name += len; 10450e47c99dSEric W. Biederman } 1046*ac13ac6fSEric W. Biederman init_header(links, dir->header.root, dir->header.set, node, link_table); 10470e47c99dSEric W. Biederman links->nreg = nr_entries; 10480e47c99dSEric W. Biederman 10490e47c99dSEric W. Biederman return links; 10500e47c99dSEric W. Biederman } 10510e47c99dSEric W. Biederman 10520e47c99dSEric W. Biederman static bool get_links(struct ctl_dir *dir, 10530e47c99dSEric W. Biederman struct ctl_table *table, struct ctl_table_root *link_root) 10540e47c99dSEric W. Biederman { 10550e47c99dSEric W. Biederman struct ctl_table_header *head; 10560e47c99dSEric W. Biederman struct ctl_table *entry, *link; 10570e47c99dSEric W. Biederman 10580e47c99dSEric W. Biederman /* Are there links available for every entry in table? */ 10590e47c99dSEric W. Biederman for (entry = table; entry->procname; entry++) { 10600e47c99dSEric W. Biederman const char *procname = entry->procname; 10610e47c99dSEric W. Biederman link = find_entry(&head, dir, procname, strlen(procname)); 10620e47c99dSEric W. Biederman if (!link) 10630e47c99dSEric W. Biederman return false; 10640e47c99dSEric W. Biederman if (S_ISDIR(link->mode) && S_ISDIR(entry->mode)) 10650e47c99dSEric W. Biederman continue; 10660e47c99dSEric W. Biederman if (S_ISLNK(link->mode) && (link->data == link_root)) 10670e47c99dSEric W. Biederman continue; 10680e47c99dSEric W. Biederman return false; 10690e47c99dSEric W. Biederman } 10700e47c99dSEric W. Biederman 10710e47c99dSEric W. Biederman /* The checks passed. Increase the registration count on the links */ 10720e47c99dSEric W. Biederman for (entry = table; entry->procname; entry++) { 10730e47c99dSEric W. Biederman const char *procname = entry->procname; 10740e47c99dSEric W. Biederman link = find_entry(&head, dir, procname, strlen(procname)); 10750e47c99dSEric W. Biederman head->nreg++; 10760e47c99dSEric W. Biederman } 10770e47c99dSEric W. Biederman return true; 10780e47c99dSEric W. Biederman } 10790e47c99dSEric W. Biederman 10800e47c99dSEric W. Biederman static int insert_links(struct ctl_table_header *head) 10810e47c99dSEric W. Biederman { 10820e47c99dSEric W. Biederman struct ctl_table_set *root_set = &sysctl_table_root.default_set; 10830e47c99dSEric W. Biederman struct ctl_dir *core_parent = NULL; 10840e47c99dSEric W. Biederman struct ctl_table_header *links; 10850e47c99dSEric W. Biederman int err; 10860e47c99dSEric W. Biederman 10870e47c99dSEric W. Biederman if (head->set == root_set) 10880e47c99dSEric W. Biederman return 0; 10890e47c99dSEric W. Biederman 10900e47c99dSEric W. Biederman core_parent = xlate_dir(root_set, head->parent); 10910e47c99dSEric W. Biederman if (IS_ERR(core_parent)) 10920e47c99dSEric W. Biederman return 0; 10930e47c99dSEric W. Biederman 10940e47c99dSEric W. Biederman if (get_links(core_parent, head->ctl_table, head->root)) 10950e47c99dSEric W. Biederman return 0; 10960e47c99dSEric W. Biederman 10970e47c99dSEric W. Biederman core_parent->header.nreg++; 10980e47c99dSEric W. Biederman spin_unlock(&sysctl_lock); 10990e47c99dSEric W. Biederman 11000e47c99dSEric W. Biederman links = new_links(core_parent, head->ctl_table, head->root); 11010e47c99dSEric W. Biederman 11020e47c99dSEric W. Biederman spin_lock(&sysctl_lock); 11030e47c99dSEric W. Biederman err = -ENOMEM; 11040e47c99dSEric W. Biederman if (!links) 11050e47c99dSEric W. Biederman goto out; 11060e47c99dSEric W. Biederman 11070e47c99dSEric W. Biederman err = 0; 11080e47c99dSEric W. Biederman if (get_links(core_parent, head->ctl_table, head->root)) { 11090e47c99dSEric W. Biederman kfree(links); 11100e47c99dSEric W. Biederman goto out; 11110e47c99dSEric W. Biederman } 11120e47c99dSEric W. Biederman 11130e47c99dSEric W. Biederman err = insert_header(core_parent, links); 11140e47c99dSEric W. Biederman if (err) 11150e47c99dSEric W. Biederman kfree(links); 11160e47c99dSEric W. Biederman out: 11170e47c99dSEric W. Biederman drop_sysctl_table(&core_parent->header); 11180e47c99dSEric W. Biederman return err; 11190e47c99dSEric W. Biederman } 11200e47c99dSEric W. Biederman 11211f87f0b5SEric W. Biederman /** 1122f728019bSEric W. Biederman * __register_sysctl_table - register a leaf sysctl table 112360a47a2eSEric W. Biederman * @set: Sysctl tree to register on 11241f87f0b5SEric W. Biederman * @path: The path to the directory the sysctl table is in. 11251f87f0b5SEric W. Biederman * @table: the top-level table structure 11261f87f0b5SEric W. Biederman * 11271f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 11281f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 11291f87f0b5SEric W. Biederman * 11301f87f0b5SEric W. Biederman * The members of the &struct ctl_table structure are used as follows: 11311f87f0b5SEric W. Biederman * 11321f87f0b5SEric W. Biederman * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not 11331f87f0b5SEric W. Biederman * enter a sysctl file 11341f87f0b5SEric W. Biederman * 11351f87f0b5SEric W. Biederman * data - a pointer to data for use by proc_handler 11361f87f0b5SEric W. Biederman * 11371f87f0b5SEric W. Biederman * maxlen - the maximum size in bytes of the data 11381f87f0b5SEric W. Biederman * 1139f728019bSEric W. Biederman * mode - the file permissions for the /proc/sys file 11401f87f0b5SEric W. Biederman * 1141f728019bSEric W. Biederman * child - must be %NULL. 11421f87f0b5SEric W. Biederman * 11431f87f0b5SEric W. Biederman * proc_handler - the text handler routine (described below) 11441f87f0b5SEric W. Biederman * 11451f87f0b5SEric W. Biederman * extra1, extra2 - extra pointers usable by the proc handler routines 11461f87f0b5SEric W. Biederman * 11471f87f0b5SEric W. Biederman * Leaf nodes in the sysctl tree will be represented by a single file 11481f87f0b5SEric W. Biederman * under /proc; non-leaf nodes will be represented by directories. 11491f87f0b5SEric W. Biederman * 1150f728019bSEric W. Biederman * There must be a proc_handler routine for any terminal nodes. 1151f728019bSEric W. Biederman * Several default handlers are available to cover common cases - 11521f87f0b5SEric W. Biederman * 11531f87f0b5SEric W. Biederman * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), 11541f87f0b5SEric W. Biederman * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 11551f87f0b5SEric W. Biederman * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() 11561f87f0b5SEric W. Biederman * 11571f87f0b5SEric W. Biederman * It is the handler's job to read the input buffer from user memory 11581f87f0b5SEric W. Biederman * and process it. The handler should return 0 on success. 11591f87f0b5SEric W. Biederman * 11601f87f0b5SEric W. Biederman * This routine returns %NULL on a failure to register, and a pointer 11611f87f0b5SEric W. Biederman * to the table header on success. 11621f87f0b5SEric W. Biederman */ 11636e9d5164SEric W. Biederman struct ctl_table_header *__register_sysctl_table( 116460a47a2eSEric W. Biederman struct ctl_table_set *set, 11656e9d5164SEric W. Biederman const char *path, struct ctl_table *table) 11661f87f0b5SEric W. Biederman { 116760a47a2eSEric W. Biederman struct ctl_table_root *root = set->dir.header.root; 11680e47c99dSEric W. Biederman struct ctl_table_header *links = NULL; 11691f87f0b5SEric W. Biederman struct ctl_table_header *header; 11706e9d5164SEric W. Biederman const char *name, *nextname; 11717ec66d06SEric W. Biederman struct ctl_dir *dir; 1172*ac13ac6fSEric W. Biederman struct ctl_table *entry; 1173*ac13ac6fSEric W. Biederman struct ctl_node *node; 1174*ac13ac6fSEric W. Biederman int nr_entries = 0; 11751f87f0b5SEric W. Biederman 1176*ac13ac6fSEric W. Biederman for (entry = table; entry->procname; entry++) 1177*ac13ac6fSEric W. Biederman nr_entries++; 1178*ac13ac6fSEric W. Biederman 1179*ac13ac6fSEric W. Biederman header = kzalloc(sizeof(struct ctl_table_header) + 1180*ac13ac6fSEric W. Biederman sizeof(struct ctl_node)*nr_entries, GFP_KERNEL); 11811f87f0b5SEric W. Biederman if (!header) 11821f87f0b5SEric W. Biederman return NULL; 11831f87f0b5SEric W. Biederman 1184*ac13ac6fSEric W. Biederman node = (struct ctl_node *)(header + 1); 1185*ac13ac6fSEric W. Biederman init_header(header, root, set, node, table); 11867c60c48fSEric W. Biederman if (sysctl_check_table(path, table)) 11877c60c48fSEric W. Biederman goto fail; 11888d6ecfccSEric W. Biederman 11891f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 11900e47c99dSEric W. Biederman dir = &set->dir; 11917ec66d06SEric W. Biederman dir->header.nreg++; 11927ec66d06SEric W. Biederman spin_unlock(&sysctl_lock); 11937ec66d06SEric W. Biederman 11947ec66d06SEric W. Biederman /* Find the directory for the ctl_table */ 11957ec66d06SEric W. Biederman for (name = path; name; name = nextname) { 11967ec66d06SEric W. Biederman int namelen; 11977ec66d06SEric W. Biederman nextname = strchr(name, '/'); 11987ec66d06SEric W. Biederman if (nextname) { 11997ec66d06SEric W. Biederman namelen = nextname - name; 12007ec66d06SEric W. Biederman nextname++; 12017ec66d06SEric W. Biederman } else { 12027ec66d06SEric W. Biederman namelen = strlen(name); 12037ec66d06SEric W. Biederman } 12047ec66d06SEric W. Biederman if (namelen == 0) 12051f87f0b5SEric W. Biederman continue; 12067ec66d06SEric W. Biederman 12070e47c99dSEric W. Biederman dir = get_subdir(dir, name, namelen); 12087ec66d06SEric W. Biederman if (IS_ERR(dir)) 12097ec66d06SEric W. Biederman goto fail; 12101f87f0b5SEric W. Biederman } 12110e47c99dSEric W. Biederman 12127ec66d06SEric W. Biederman spin_lock(&sysctl_lock); 12130e47c99dSEric W. Biederman if (insert_header(dir, header)) 12140e47c99dSEric W. Biederman goto fail_put_dir_locked; 12150e47c99dSEric W. Biederman 12167ec66d06SEric W. Biederman drop_sysctl_table(&dir->header); 12171f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 12181f87f0b5SEric W. Biederman 12191f87f0b5SEric W. Biederman return header; 12200e47c99dSEric W. Biederman 12217ec66d06SEric W. Biederman fail_put_dir_locked: 12227ec66d06SEric W. Biederman drop_sysctl_table(&dir->header); 12237c60c48fSEric W. Biederman spin_unlock(&sysctl_lock); 12247c60c48fSEric W. Biederman fail: 12250e47c99dSEric W. Biederman kfree(links); 12267c60c48fSEric W. Biederman kfree(header); 12277c60c48fSEric W. Biederman dump_stack(); 12287c60c48fSEric W. Biederman return NULL; 12291f87f0b5SEric W. Biederman } 12301f87f0b5SEric W. Biederman 12316e9d5164SEric W. Biederman static char *append_path(const char *path, char *pos, const char *name) 12326e9d5164SEric W. Biederman { 12336e9d5164SEric W. Biederman int namelen; 12346e9d5164SEric W. Biederman namelen = strlen(name); 12356e9d5164SEric W. Biederman if (((pos - path) + namelen + 2) >= PATH_MAX) 12366e9d5164SEric W. Biederman return NULL; 12376e9d5164SEric W. Biederman memcpy(pos, name, namelen); 12386e9d5164SEric W. Biederman pos[namelen] = '/'; 12396e9d5164SEric W. Biederman pos[namelen + 1] = '\0'; 12406e9d5164SEric W. Biederman pos += namelen + 1; 12416e9d5164SEric W. Biederman return pos; 12426e9d5164SEric W. Biederman } 12436e9d5164SEric W. Biederman 1244f728019bSEric W. Biederman static int count_subheaders(struct ctl_table *table) 1245f728019bSEric W. Biederman { 1246f728019bSEric W. Biederman int has_files = 0; 1247f728019bSEric W. Biederman int nr_subheaders = 0; 1248f728019bSEric W. Biederman struct ctl_table *entry; 1249f728019bSEric W. Biederman 1250f728019bSEric W. Biederman /* special case: no directory and empty directory */ 1251f728019bSEric W. Biederman if (!table || !table->procname) 1252f728019bSEric W. Biederman return 1; 1253f728019bSEric W. Biederman 1254f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1255f728019bSEric W. Biederman if (entry->child) 1256f728019bSEric W. Biederman nr_subheaders += count_subheaders(entry->child); 1257f728019bSEric W. Biederman else 1258f728019bSEric W. Biederman has_files = 1; 1259f728019bSEric W. Biederman } 1260f728019bSEric W. Biederman return nr_subheaders + has_files; 1261f728019bSEric W. Biederman } 1262f728019bSEric W. Biederman 1263f728019bSEric W. Biederman static int register_leaf_sysctl_tables(const char *path, char *pos, 126460a47a2eSEric W. Biederman struct ctl_table_header ***subheader, struct ctl_table_set *set, 1265f728019bSEric W. Biederman struct ctl_table *table) 1266f728019bSEric W. Biederman { 1267f728019bSEric W. Biederman struct ctl_table *ctl_table_arg = NULL; 1268f728019bSEric W. Biederman struct ctl_table *entry, *files; 1269f728019bSEric W. Biederman int nr_files = 0; 1270f728019bSEric W. Biederman int nr_dirs = 0; 1271f728019bSEric W. Biederman int err = -ENOMEM; 1272f728019bSEric W. Biederman 1273f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1274f728019bSEric W. Biederman if (entry->child) 1275f728019bSEric W. Biederman nr_dirs++; 1276f728019bSEric W. Biederman else 1277f728019bSEric W. Biederman nr_files++; 1278f728019bSEric W. Biederman } 1279f728019bSEric W. Biederman 1280f728019bSEric W. Biederman files = table; 1281f728019bSEric W. Biederman /* If there are mixed files and directories we need a new table */ 1282f728019bSEric W. Biederman if (nr_dirs && nr_files) { 1283f728019bSEric W. Biederman struct ctl_table *new; 1284f728019bSEric W. Biederman files = kzalloc(sizeof(struct ctl_table) * (nr_files + 1), 1285f728019bSEric W. Biederman GFP_KERNEL); 1286f728019bSEric W. Biederman if (!files) 1287f728019bSEric W. Biederman goto out; 1288f728019bSEric W. Biederman 1289f728019bSEric W. Biederman ctl_table_arg = files; 1290f728019bSEric W. Biederman for (new = files, entry = table; entry->procname; entry++) { 1291f728019bSEric W. Biederman if (entry->child) 1292f728019bSEric W. Biederman continue; 1293f728019bSEric W. Biederman *new = *entry; 1294f728019bSEric W. Biederman new++; 1295f728019bSEric W. Biederman } 1296f728019bSEric W. Biederman } 1297f728019bSEric W. Biederman 1298f728019bSEric W. Biederman /* Register everything except a directory full of subdirectories */ 1299f728019bSEric W. Biederman if (nr_files || !nr_dirs) { 1300f728019bSEric W. Biederman struct ctl_table_header *header; 130160a47a2eSEric W. Biederman header = __register_sysctl_table(set, path, files); 1302f728019bSEric W. Biederman if (!header) { 1303f728019bSEric W. Biederman kfree(ctl_table_arg); 1304f728019bSEric W. Biederman goto out; 1305f728019bSEric W. Biederman } 1306f728019bSEric W. Biederman 1307f728019bSEric W. Biederman /* Remember if we need to free the file table */ 1308f728019bSEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1309f728019bSEric W. Biederman **subheader = header; 1310f728019bSEric W. Biederman (*subheader)++; 1311f728019bSEric W. Biederman } 1312f728019bSEric W. Biederman 1313f728019bSEric W. Biederman /* Recurse into the subdirectories. */ 1314f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1315f728019bSEric W. Biederman char *child_pos; 1316f728019bSEric W. Biederman 1317f728019bSEric W. Biederman if (!entry->child) 1318f728019bSEric W. Biederman continue; 1319f728019bSEric W. Biederman 1320f728019bSEric W. Biederman err = -ENAMETOOLONG; 1321f728019bSEric W. Biederman child_pos = append_path(path, pos, entry->procname); 1322f728019bSEric W. Biederman if (!child_pos) 1323f728019bSEric W. Biederman goto out; 1324f728019bSEric W. Biederman 1325f728019bSEric W. Biederman err = register_leaf_sysctl_tables(path, child_pos, subheader, 132660a47a2eSEric W. Biederman set, entry->child); 1327f728019bSEric W. Biederman pos[0] = '\0'; 1328f728019bSEric W. Biederman if (err) 1329f728019bSEric W. Biederman goto out; 1330f728019bSEric W. Biederman } 1331f728019bSEric W. Biederman err = 0; 1332f728019bSEric W. Biederman out: 1333f728019bSEric W. Biederman /* On failure our caller will unregister all registered subheaders */ 1334f728019bSEric W. Biederman return err; 1335f728019bSEric W. Biederman } 1336f728019bSEric W. Biederman 13376e9d5164SEric W. Biederman /** 13386e9d5164SEric W. Biederman * __register_sysctl_paths - register a sysctl table hierarchy 133960a47a2eSEric W. Biederman * @set: Sysctl tree to register on 13406e9d5164SEric W. Biederman * @path: The path to the directory the sysctl table is in. 13416e9d5164SEric W. Biederman * @table: the top-level table structure 13426e9d5164SEric W. Biederman * 13436e9d5164SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 13446e9d5164SEric W. Biederman * array. A completely 0 filled entry terminates the table. 13456e9d5164SEric W. Biederman * 13466e9d5164SEric W. Biederman * See __register_sysctl_table for more details. 13476e9d5164SEric W. Biederman */ 13486e9d5164SEric W. Biederman struct ctl_table_header *__register_sysctl_paths( 134960a47a2eSEric W. Biederman struct ctl_table_set *set, 13506e9d5164SEric W. Biederman const struct ctl_path *path, struct ctl_table *table) 13516e9d5164SEric W. Biederman { 1352ec6a5266SEric W. Biederman struct ctl_table *ctl_table_arg = table; 1353f728019bSEric W. Biederman int nr_subheaders = count_subheaders(table); 1354f728019bSEric W. Biederman struct ctl_table_header *header = NULL, **subheaders, **subheader; 13556e9d5164SEric W. Biederman const struct ctl_path *component; 13566e9d5164SEric W. Biederman char *new_path, *pos; 13576e9d5164SEric W. Biederman 13586e9d5164SEric W. Biederman pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); 13596e9d5164SEric W. Biederman if (!new_path) 13606e9d5164SEric W. Biederman return NULL; 13616e9d5164SEric W. Biederman 13626e9d5164SEric W. Biederman pos[0] = '\0'; 13636e9d5164SEric W. Biederman for (component = path; component->procname; component++) { 13646e9d5164SEric W. Biederman pos = append_path(new_path, pos, component->procname); 13656e9d5164SEric W. Biederman if (!pos) 13666e9d5164SEric W. Biederman goto out; 13676e9d5164SEric W. Biederman } 1368ec6a5266SEric W. Biederman while (table->procname && table->child && !table[1].procname) { 1369ec6a5266SEric W. Biederman pos = append_path(new_path, pos, table->procname); 1370ec6a5266SEric W. Biederman if (!pos) 1371ec6a5266SEric W. Biederman goto out; 1372ec6a5266SEric W. Biederman table = table->child; 1373ec6a5266SEric W. Biederman } 1374f728019bSEric W. Biederman if (nr_subheaders == 1) { 137560a47a2eSEric W. Biederman header = __register_sysctl_table(set, new_path, table); 1376ec6a5266SEric W. Biederman if (header) 1377ec6a5266SEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1378f728019bSEric W. Biederman } else { 1379f728019bSEric W. Biederman header = kzalloc(sizeof(*header) + 1380f728019bSEric W. Biederman sizeof(*subheaders)*nr_subheaders, GFP_KERNEL); 1381f728019bSEric W. Biederman if (!header) 1382f728019bSEric W. Biederman goto out; 1383f728019bSEric W. Biederman 1384f728019bSEric W. Biederman subheaders = (struct ctl_table_header **) (header + 1); 1385f728019bSEric W. Biederman subheader = subheaders; 1386f728019bSEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1387f728019bSEric W. Biederman 1388f728019bSEric W. Biederman if (register_leaf_sysctl_tables(new_path, pos, &subheader, 138960a47a2eSEric W. Biederman set, table)) 1390f728019bSEric W. Biederman goto err_register_leaves; 1391f728019bSEric W. Biederman } 1392f728019bSEric W. Biederman 13936e9d5164SEric W. Biederman out: 13946e9d5164SEric W. Biederman kfree(new_path); 13956e9d5164SEric W. Biederman return header; 1396f728019bSEric W. Biederman 1397f728019bSEric W. Biederman err_register_leaves: 1398f728019bSEric W. Biederman while (subheader > subheaders) { 1399f728019bSEric W. Biederman struct ctl_table_header *subh = *(--subheader); 1400f728019bSEric W. Biederman struct ctl_table *table = subh->ctl_table_arg; 1401f728019bSEric W. Biederman unregister_sysctl_table(subh); 1402f728019bSEric W. Biederman kfree(table); 1403f728019bSEric W. Biederman } 1404f728019bSEric W. Biederman kfree(header); 1405f728019bSEric W. Biederman header = NULL; 1406f728019bSEric W. Biederman goto out; 14076e9d5164SEric W. Biederman } 14086e9d5164SEric W. Biederman 14091f87f0b5SEric W. Biederman /** 14101f87f0b5SEric W. Biederman * register_sysctl_table_path - register a sysctl table hierarchy 14111f87f0b5SEric W. Biederman * @path: The path to the directory the sysctl table is in. 14121f87f0b5SEric W. Biederman * @table: the top-level table structure 14131f87f0b5SEric W. Biederman * 14141f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 14151f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 14161f87f0b5SEric W. Biederman * 14171f87f0b5SEric W. Biederman * See __register_sysctl_paths for more details. 14181f87f0b5SEric W. Biederman */ 14191f87f0b5SEric W. Biederman struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, 14201f87f0b5SEric W. Biederman struct ctl_table *table) 14211f87f0b5SEric W. Biederman { 142260a47a2eSEric W. Biederman return __register_sysctl_paths(&sysctl_table_root.default_set, 14231f87f0b5SEric W. Biederman path, table); 14241f87f0b5SEric W. Biederman } 14251f87f0b5SEric W. Biederman EXPORT_SYMBOL(register_sysctl_paths); 14261f87f0b5SEric W. Biederman 14271f87f0b5SEric W. Biederman /** 14281f87f0b5SEric W. Biederman * register_sysctl_table - register a sysctl table hierarchy 14291f87f0b5SEric W. Biederman * @table: the top-level table structure 14301f87f0b5SEric W. Biederman * 14311f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 14321f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 14331f87f0b5SEric W. Biederman * 14341f87f0b5SEric W. Biederman * See register_sysctl_paths for more details. 14351f87f0b5SEric W. Biederman */ 14361f87f0b5SEric W. Biederman struct ctl_table_header *register_sysctl_table(struct ctl_table *table) 14371f87f0b5SEric W. Biederman { 14381f87f0b5SEric W. Biederman static const struct ctl_path null_path[] = { {} }; 14391f87f0b5SEric W. Biederman 14401f87f0b5SEric W. Biederman return register_sysctl_paths(null_path, table); 14411f87f0b5SEric W. Biederman } 14421f87f0b5SEric W. Biederman EXPORT_SYMBOL(register_sysctl_table); 14431f87f0b5SEric W. Biederman 14440e47c99dSEric W. Biederman static void put_links(struct ctl_table_header *header) 14450e47c99dSEric W. Biederman { 14460e47c99dSEric W. Biederman struct ctl_table_set *root_set = &sysctl_table_root.default_set; 14470e47c99dSEric W. Biederman struct ctl_table_root *root = header->root; 14480e47c99dSEric W. Biederman struct ctl_dir *parent = header->parent; 14490e47c99dSEric W. Biederman struct ctl_dir *core_parent; 14500e47c99dSEric W. Biederman struct ctl_table *entry; 14510e47c99dSEric W. Biederman 14520e47c99dSEric W. Biederman if (header->set == root_set) 14530e47c99dSEric W. Biederman return; 14540e47c99dSEric W. Biederman 14550e47c99dSEric W. Biederman core_parent = xlate_dir(root_set, parent); 14560e47c99dSEric W. Biederman if (IS_ERR(core_parent)) 14570e47c99dSEric W. Biederman return; 14580e47c99dSEric W. Biederman 14590e47c99dSEric W. Biederman for (entry = header->ctl_table; entry->procname; entry++) { 14600e47c99dSEric W. Biederman struct ctl_table_header *link_head; 14610e47c99dSEric W. Biederman struct ctl_table *link; 14620e47c99dSEric W. Biederman const char *name = entry->procname; 14630e47c99dSEric W. Biederman 14640e47c99dSEric W. Biederman link = find_entry(&link_head, core_parent, name, strlen(name)); 14650e47c99dSEric W. Biederman if (link && 14660e47c99dSEric W. Biederman ((S_ISDIR(link->mode) && S_ISDIR(entry->mode)) || 14670e47c99dSEric W. Biederman (S_ISLNK(link->mode) && (link->data == root)))) { 14680e47c99dSEric W. Biederman drop_sysctl_table(link_head); 14690e47c99dSEric W. Biederman } 14700e47c99dSEric W. Biederman else { 14710e47c99dSEric W. Biederman printk(KERN_ERR "sysctl link missing during unregister: "); 14720e47c99dSEric W. Biederman sysctl_print_dir(parent); 14730e47c99dSEric W. Biederman printk(KERN_CONT "/%s\n", name); 14740e47c99dSEric W. Biederman } 14750e47c99dSEric W. Biederman } 14760e47c99dSEric W. Biederman } 14770e47c99dSEric W. Biederman 1478938aaa4fSEric W. Biederman static void drop_sysctl_table(struct ctl_table_header *header) 1479938aaa4fSEric W. Biederman { 14807ec66d06SEric W. Biederman struct ctl_dir *parent = header->parent; 14817ec66d06SEric W. Biederman 1482938aaa4fSEric W. Biederman if (--header->nreg) 1483938aaa4fSEric W. Biederman return; 1484938aaa4fSEric W. Biederman 14850e47c99dSEric W. Biederman put_links(header); 1486938aaa4fSEric W. Biederman start_unregistering(header); 1487938aaa4fSEric W. Biederman if (!--header->count) 1488938aaa4fSEric W. Biederman kfree_rcu(header, rcu); 14897ec66d06SEric W. Biederman 14907ec66d06SEric W. Biederman if (parent) 14917ec66d06SEric W. Biederman drop_sysctl_table(&parent->header); 1492938aaa4fSEric W. Biederman } 1493938aaa4fSEric W. Biederman 14941f87f0b5SEric W. Biederman /** 14951f87f0b5SEric W. Biederman * unregister_sysctl_table - unregister a sysctl table hierarchy 14961f87f0b5SEric W. Biederman * @header: the header returned from register_sysctl_table 14971f87f0b5SEric W. Biederman * 14981f87f0b5SEric W. Biederman * Unregisters the sysctl table and all children. proc entries may not 14991f87f0b5SEric W. Biederman * actually be removed until they are no longer used by anyone. 15001f87f0b5SEric W. Biederman */ 15011f87f0b5SEric W. Biederman void unregister_sysctl_table(struct ctl_table_header * header) 15021f87f0b5SEric W. Biederman { 1503f728019bSEric W. Biederman int nr_subheaders; 15041f87f0b5SEric W. Biederman might_sleep(); 15051f87f0b5SEric W. Biederman 15061f87f0b5SEric W. Biederman if (header == NULL) 15071f87f0b5SEric W. Biederman return; 15081f87f0b5SEric W. Biederman 1509f728019bSEric W. Biederman nr_subheaders = count_subheaders(header->ctl_table_arg); 1510f728019bSEric W. Biederman if (unlikely(nr_subheaders > 1)) { 1511f728019bSEric W. Biederman struct ctl_table_header **subheaders; 1512f728019bSEric W. Biederman int i; 1513f728019bSEric W. Biederman 1514f728019bSEric W. Biederman subheaders = (struct ctl_table_header **)(header + 1); 1515f728019bSEric W. Biederman for (i = nr_subheaders -1; i >= 0; i--) { 1516f728019bSEric W. Biederman struct ctl_table_header *subh = subheaders[i]; 1517f728019bSEric W. Biederman struct ctl_table *table = subh->ctl_table_arg; 1518f728019bSEric W. Biederman unregister_sysctl_table(subh); 1519f728019bSEric W. Biederman kfree(table); 1520f728019bSEric W. Biederman } 1521f728019bSEric W. Biederman kfree(header); 1522f728019bSEric W. Biederman return; 1523f728019bSEric W. Biederman } 1524f728019bSEric W. Biederman 15251f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1526938aaa4fSEric W. Biederman drop_sysctl_table(header); 15271f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 15281f87f0b5SEric W. Biederman } 15291f87f0b5SEric W. Biederman EXPORT_SYMBOL(unregister_sysctl_table); 15301f87f0b5SEric W. Biederman 15310e47c99dSEric W. Biederman void setup_sysctl_set(struct ctl_table_set *set, 15329eb47c26SEric W. Biederman struct ctl_table_root *root, 15331f87f0b5SEric W. Biederman int (*is_seen)(struct ctl_table_set *)) 15341f87f0b5SEric W. Biederman { 15350e47c99dSEric W. Biederman memset(set, sizeof(*set), 0); 15360e47c99dSEric W. Biederman set->is_seen = is_seen; 1537*ac13ac6fSEric W. Biederman init_header(&set->dir.header, root, set, NULL, root_table); 15381f87f0b5SEric W. Biederman } 15391f87f0b5SEric W. Biederman 154097324cd8SEric W. Biederman void retire_sysctl_set(struct ctl_table_set *set) 154197324cd8SEric W. Biederman { 1542*ac13ac6fSEric W. Biederman WARN_ON(!RB_EMPTY_ROOT(&set->dir.root)); 154397324cd8SEric W. Biederman } 15441f87f0b5SEric W. Biederman 15451e0edd3fSAlexey Dobriyan int __init proc_sys_init(void) 154677b14db5SEric W. Biederman { 1547e1675231SAlexey Dobriyan struct proc_dir_entry *proc_sys_root; 1548e1675231SAlexey Dobriyan 154977b14db5SEric W. Biederman proc_sys_root = proc_mkdir("sys", NULL); 15509043476fSAl Viro proc_sys_root->proc_iops = &proc_sys_dir_operations; 15519043476fSAl Viro proc_sys_root->proc_fops = &proc_sys_dir_file_operations; 155277b14db5SEric W. Biederman proc_sys_root->nlink = 0; 1553de4e83bdSEric W. Biederman 1554de4e83bdSEric W. Biederman return sysctl_init(); 155577b14db5SEric W. Biederman } 1556