1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0 277b14db5SEric W. Biederman /* 377b14db5SEric W. Biederman * /proc/sys support 477b14db5SEric W. Biederman */ 51e0edd3fSAlexey Dobriyan #include <linux/init.h> 677b14db5SEric W. Biederman #include <linux/sysctl.h> 7f1ecf068SLucas De Marchi #include <linux/poll.h> 877b14db5SEric W. Biederman #include <linux/proc_fs.h> 987ebdc00SAndrew Morton #include <linux/printk.h> 1077b14db5SEric W. Biederman #include <linux/security.h> 1140401530SAl Viro #include <linux/sched.h> 125b825c3aSIngo Molnar #include <linux/cred.h> 1334286d66SNick Piggin #include <linux/namei.h> 1440401530SAl Viro #include <linux/mm.h> 154bd6a735SMatthew Wilcox (Oracle) #include <linux/uio.h> 161f87f0b5SEric W. Biederman #include <linux/module.h> 177b146cebSAndrey Ignatov #include <linux/bpf-cgroup.h> 183db978d4SVlastimil Babka #include <linux/mount.h> 193ddd9a80SXiaoming Ni #include <linux/kmemleak.h> 2077b14db5SEric W. Biederman #include "internal.h" 2177b14db5SEric W. Biederman 22d72f71ebSAl Viro static const struct dentry_operations proc_sys_dentry_operations; 2377b14db5SEric W. Biederman static const struct file_operations proc_sys_file_operations; 2403a44825SJan Engelhardt static const struct inode_operations proc_sys_inode_operations; 259043476fSAl Viro static const struct file_operations proc_sys_dir_file_operations; 269043476fSAl Viro static const struct inode_operations proc_sys_dir_operations; 2777b14db5SEric W. Biederman 28eec4844fSMatteo Croce /* shared constants to be used in various sysctls */ 2954771613SLuis Chamberlain const int sysctl_vals[] = { -1, 0, 1, 2, 4, 100, 200, 1000, 3000, INT_MAX, 65535 }; 30eec4844fSMatteo Croce EXPORT_SYMBOL(sysctl_vals); 31eec4844fSMatteo Croce 32b1f2aff8SLuis Chamberlain const unsigned long sysctl_long_vals[] = { 0, 1, LONG_MAX }; 33b1f2aff8SLuis Chamberlain EXPORT_SYMBOL_GPL(sysctl_long_vals); 34b1f2aff8SLuis Chamberlain 35f9bd6733SEric W. Biederman /* Support for permanently empty directories */ 36f9bd6733SEric W. Biederman 37f9bd6733SEric W. Biederman struct ctl_table sysctl_mount_point[] = { 38f9bd6733SEric W. Biederman { } 39f9bd6733SEric W. Biederman }; 40f9bd6733SEric W. Biederman 41ee9efac4SLuis Chamberlain /** 42ee9efac4SLuis Chamberlain * register_sysctl_mount_point() - registers a sysctl mount point 43ee9efac4SLuis Chamberlain * @path: path for the mount point 44ee9efac4SLuis Chamberlain * 45ee9efac4SLuis Chamberlain * Used to create a permanently empty directory to serve as mount point. 46ee9efac4SLuis Chamberlain * There are some subtle but important permission checks this allows in the 47ee9efac4SLuis Chamberlain * case of unprivileged mounts. 48ee9efac4SLuis Chamberlain */ 49ee9efac4SLuis Chamberlain struct ctl_table_header *register_sysctl_mount_point(const char *path) 50ee9efac4SLuis Chamberlain { 51ee9efac4SLuis Chamberlain return register_sysctl(path, sysctl_mount_point); 52ee9efac4SLuis Chamberlain } 53ee9efac4SLuis Chamberlain EXPORT_SYMBOL(register_sysctl_mount_point); 54ee9efac4SLuis Chamberlain 55f9bd6733SEric W. Biederman static bool is_empty_dir(struct ctl_table_header *head) 56f9bd6733SEric W. Biederman { 57f9bd6733SEric W. Biederman return head->ctl_table[0].child == sysctl_mount_point; 58f9bd6733SEric W. Biederman } 59f9bd6733SEric W. Biederman 60f9bd6733SEric W. Biederman static void set_empty_dir(struct ctl_dir *dir) 61f9bd6733SEric W. Biederman { 62f9bd6733SEric W. Biederman dir->header.ctl_table[0].child = sysctl_mount_point; 63f9bd6733SEric W. Biederman } 64f9bd6733SEric W. Biederman 65f9bd6733SEric W. Biederman static void clear_empty_dir(struct ctl_dir *dir) 66f9bd6733SEric W. Biederman 67f9bd6733SEric W. Biederman { 68f9bd6733SEric W. Biederman dir->header.ctl_table[0].child = NULL; 69f9bd6733SEric W. Biederman } 70f9bd6733SEric W. Biederman 71f1ecf068SLucas De Marchi void proc_sys_poll_notify(struct ctl_table_poll *poll) 72f1ecf068SLucas De Marchi { 73f1ecf068SLucas De Marchi if (!poll) 74f1ecf068SLucas De Marchi return; 75f1ecf068SLucas De Marchi 76f1ecf068SLucas De Marchi atomic_inc(&poll->event); 77f1ecf068SLucas De Marchi wake_up_interruptible(&poll->wait); 78f1ecf068SLucas De Marchi } 79f1ecf068SLucas De Marchi 80a194558eSEric W. Biederman static struct ctl_table root_table[] = { 81a194558eSEric W. Biederman { 82a194558eSEric W. Biederman .procname = "", 837ec66d06SEric W. Biederman .mode = S_IFDIR|S_IRUGO|S_IXUGO, 84a194558eSEric W. Biederman }, 85a194558eSEric W. Biederman { } 86a194558eSEric W. Biederman }; 870e47c99dSEric W. Biederman static struct ctl_table_root sysctl_table_root = { 880e47c99dSEric W. Biederman .default_set.dir.header = { 891f87f0b5SEric W. Biederman {{.count = 1, 90938aaa4fSEric W. Biederman .nreg = 1, 91ac13ac6fSEric W. Biederman .ctl_table = root_table }}, 920e47c99dSEric W. Biederman .ctl_table_arg = root_table, 931f87f0b5SEric W. Biederman .root = &sysctl_table_root, 941f87f0b5SEric W. Biederman .set = &sysctl_table_root.default_set, 957ec66d06SEric W. Biederman }, 961f87f0b5SEric W. Biederman }; 971f87f0b5SEric W. Biederman 981f87f0b5SEric W. Biederman static DEFINE_SPINLOCK(sysctl_lock); 991f87f0b5SEric W. Biederman 1007ec66d06SEric W. Biederman static void drop_sysctl_table(struct ctl_table_header *header); 1010e47c99dSEric W. Biederman static int sysctl_follow_link(struct ctl_table_header **phead, 10213bcc6a2SEric W. Biederman struct ctl_table **pentry); 1030e47c99dSEric W. Biederman static int insert_links(struct ctl_table_header *head); 1040e47c99dSEric W. Biederman static void put_links(struct ctl_table_header *header); 1057ec66d06SEric W. Biederman 1066980128fSEric W. Biederman static void sysctl_print_dir(struct ctl_dir *dir) 1076980128fSEric W. Biederman { 1086980128fSEric W. Biederman if (dir->header.parent) 1096980128fSEric W. Biederman sysctl_print_dir(dir->header.parent); 11087ebdc00SAndrew Morton pr_cont("%s/", dir->header.ctl_table[0].procname); 1116980128fSEric W. Biederman } 1126980128fSEric W. Biederman 113076c3eedSEric W. Biederman static int namecmp(const char *name1, int len1, const char *name2, int len2) 114076c3eedSEric W. Biederman { 115076c3eedSEric W. Biederman int cmp; 116076c3eedSEric W. Biederman 117d8fc9b66SMasahiro Yamada cmp = memcmp(name1, name2, min(len1, len2)); 118076c3eedSEric W. Biederman if (cmp == 0) 119076c3eedSEric W. Biederman cmp = len1 - len2; 120076c3eedSEric W. Biederman return cmp; 121076c3eedSEric W. Biederman } 122076c3eedSEric W. Biederman 12360f126d9SEric W. Biederman /* Called under sysctl_lock */ 124076c3eedSEric W. Biederman static struct ctl_table *find_entry(struct ctl_table_header **phead, 1250e47c99dSEric W. Biederman struct ctl_dir *dir, const char *name, int namelen) 126076c3eedSEric W. Biederman { 127076c3eedSEric W. Biederman struct ctl_table_header *head; 128076c3eedSEric W. Biederman struct ctl_table *entry; 129ac13ac6fSEric W. Biederman struct rb_node *node = dir->root.rb_node; 130076c3eedSEric W. Biederman 131ac13ac6fSEric W. Biederman while (node) 132ac13ac6fSEric W. Biederman { 133ac13ac6fSEric W. Biederman struct ctl_node *ctl_node; 134ac13ac6fSEric W. Biederman const char *procname; 135ac13ac6fSEric W. Biederman int cmp; 136ac13ac6fSEric W. Biederman 137ac13ac6fSEric W. Biederman ctl_node = rb_entry(node, struct ctl_node, node); 138ac13ac6fSEric W. Biederman head = ctl_node->header; 139ac13ac6fSEric W. Biederman entry = &head->ctl_table[ctl_node - head->node]; 140ac13ac6fSEric W. Biederman procname = entry->procname; 141ac13ac6fSEric W. Biederman 142ac13ac6fSEric W. Biederman cmp = namecmp(name, namelen, procname, strlen(procname)); 143ac13ac6fSEric W. Biederman if (cmp < 0) 144ac13ac6fSEric W. Biederman node = node->rb_left; 145ac13ac6fSEric W. Biederman else if (cmp > 0) 146ac13ac6fSEric W. Biederman node = node->rb_right; 147ac13ac6fSEric W. Biederman else { 148076c3eedSEric W. Biederman *phead = head; 149076c3eedSEric W. Biederman return entry; 150076c3eedSEric W. Biederman } 151076c3eedSEric W. Biederman } 152076c3eedSEric W. Biederman return NULL; 153076c3eedSEric W. Biederman } 154076c3eedSEric W. Biederman 155ac13ac6fSEric W. Biederman static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry) 156ac13ac6fSEric W. Biederman { 157ac13ac6fSEric W. Biederman struct rb_node *node = &head->node[entry - head->ctl_table].node; 158ac13ac6fSEric W. Biederman struct rb_node **p = &head->parent->root.rb_node; 159ac13ac6fSEric W. Biederman struct rb_node *parent = NULL; 160ac13ac6fSEric W. Biederman const char *name = entry->procname; 161ac13ac6fSEric W. Biederman int namelen = strlen(name); 162ac13ac6fSEric W. Biederman 163ac13ac6fSEric W. Biederman while (*p) { 164ac13ac6fSEric W. Biederman struct ctl_table_header *parent_head; 165ac13ac6fSEric W. Biederman struct ctl_table *parent_entry; 166ac13ac6fSEric W. Biederman struct ctl_node *parent_node; 167ac13ac6fSEric W. Biederman const char *parent_name; 168ac13ac6fSEric W. Biederman int cmp; 169ac13ac6fSEric W. Biederman 170ac13ac6fSEric W. Biederman parent = *p; 171ac13ac6fSEric W. Biederman parent_node = rb_entry(parent, struct ctl_node, node); 172ac13ac6fSEric W. Biederman parent_head = parent_node->header; 173ac13ac6fSEric W. Biederman parent_entry = &parent_head->ctl_table[parent_node - parent_head->node]; 174ac13ac6fSEric W. Biederman parent_name = parent_entry->procname; 175ac13ac6fSEric W. Biederman 176ac13ac6fSEric W. Biederman cmp = namecmp(name, namelen, parent_name, strlen(parent_name)); 177ac13ac6fSEric W. Biederman if (cmp < 0) 178ac13ac6fSEric W. Biederman p = &(*p)->rb_left; 179ac13ac6fSEric W. Biederman else if (cmp > 0) 180ac13ac6fSEric W. Biederman p = &(*p)->rb_right; 181ac13ac6fSEric W. Biederman else { 18287ebdc00SAndrew Morton pr_err("sysctl duplicate entry: "); 183ac13ac6fSEric W. Biederman sysctl_print_dir(head->parent); 184153ee1c4SGeert Uytterhoeven pr_cont("%s\n", entry->procname); 185ac13ac6fSEric W. Biederman return -EEXIST; 186ac13ac6fSEric W. Biederman } 187ac13ac6fSEric W. Biederman } 188ac13ac6fSEric W. Biederman 189ac13ac6fSEric W. Biederman rb_link_node(node, parent, p); 190ea5272f5SMichel Lespinasse rb_insert_color(node, &head->parent->root); 191ac13ac6fSEric W. Biederman return 0; 192ac13ac6fSEric W. Biederman } 193ac13ac6fSEric W. Biederman 194ac13ac6fSEric W. Biederman static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry) 195ac13ac6fSEric W. Biederman { 196ac13ac6fSEric W. Biederman struct rb_node *node = &head->node[entry - head->ctl_table].node; 197ac13ac6fSEric W. Biederman 198ac13ac6fSEric W. Biederman rb_erase(node, &head->parent->root); 199ac13ac6fSEric W. Biederman } 200ac13ac6fSEric W. Biederman 201e0d04529SEric W. Biederman static void init_header(struct ctl_table_header *head, 202e0d04529SEric W. Biederman struct ctl_table_root *root, struct ctl_table_set *set, 203ac13ac6fSEric W. Biederman struct ctl_node *node, struct ctl_table *table) 204e0d04529SEric W. Biederman { 2057ec66d06SEric W. Biederman head->ctl_table = table; 206e0d04529SEric W. Biederman head->ctl_table_arg = table; 207e0d04529SEric W. Biederman head->used = 0; 208e0d04529SEric W. Biederman head->count = 1; 209e0d04529SEric W. Biederman head->nreg = 1; 210e0d04529SEric W. Biederman head->unregistering = NULL; 211e0d04529SEric W. Biederman head->root = root; 212e0d04529SEric W. Biederman head->set = set; 213e0d04529SEric W. Biederman head->parent = NULL; 214ac13ac6fSEric W. Biederman head->node = node; 2152fd1d2c4SEric W. Biederman INIT_HLIST_HEAD(&head->inodes); 216ac13ac6fSEric W. Biederman if (node) { 217ac13ac6fSEric W. Biederman struct ctl_table *entry; 2184c199a93SMichel Lespinasse for (entry = table; entry->procname; entry++, node++) 219ac13ac6fSEric W. Biederman node->header = head; 220ac13ac6fSEric W. Biederman } 221ac13ac6fSEric W. Biederman } 222e0d04529SEric W. Biederman 2238425d6aaSEric W. Biederman static void erase_header(struct ctl_table_header *head) 2248425d6aaSEric W. Biederman { 225ac13ac6fSEric W. Biederman struct ctl_table *entry; 226ac13ac6fSEric W. Biederman for (entry = head->ctl_table; entry->procname; entry++) 227ac13ac6fSEric W. Biederman erase_entry(head, entry); 2288425d6aaSEric W. Biederman } 2298425d6aaSEric W. Biederman 2300e47c99dSEric W. Biederman static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) 2318425d6aaSEric W. Biederman { 232ac13ac6fSEric W. Biederman struct ctl_table *entry; 2330e47c99dSEric W. Biederman int err; 2340e47c99dSEric W. Biederman 235f9bd6733SEric W. Biederman /* Is this a permanently empty directory? */ 236f9bd6733SEric W. Biederman if (is_empty_dir(&dir->header)) 237f9bd6733SEric W. Biederman return -EROFS; 238f9bd6733SEric W. Biederman 239f9bd6733SEric W. Biederman /* Am I creating a permanently empty directory? */ 240f9bd6733SEric W. Biederman if (header->ctl_table == sysctl_mount_point) { 241f9bd6733SEric W. Biederman if (!RB_EMPTY_ROOT(&dir->root)) 242f9bd6733SEric W. Biederman return -EINVAL; 243f9bd6733SEric W. Biederman set_empty_dir(dir); 244f9bd6733SEric W. Biederman } 245f9bd6733SEric W. Biederman 2460e47c99dSEric W. Biederman dir->header.nreg++; 2477ec66d06SEric W. Biederman header->parent = dir; 2480e47c99dSEric W. Biederman err = insert_links(header); 2490e47c99dSEric W. Biederman if (err) 2500e47c99dSEric W. Biederman goto fail_links; 251ac13ac6fSEric W. Biederman for (entry = header->ctl_table; entry->procname; entry++) { 252ac13ac6fSEric W. Biederman err = insert_entry(header, entry); 253ac13ac6fSEric W. Biederman if (err) 254ac13ac6fSEric W. Biederman goto fail; 255ac13ac6fSEric W. Biederman } 2560e47c99dSEric W. Biederman return 0; 257ac13ac6fSEric W. Biederman fail: 258ac13ac6fSEric W. Biederman erase_header(header); 259ac13ac6fSEric W. Biederman put_links(header); 2600e47c99dSEric W. Biederman fail_links: 261f9bd6733SEric W. Biederman if (header->ctl_table == sysctl_mount_point) 262f9bd6733SEric W. Biederman clear_empty_dir(dir); 2630e47c99dSEric W. Biederman header->parent = NULL; 2640e47c99dSEric W. Biederman drop_sysctl_table(&dir->header); 2650e47c99dSEric W. Biederman return err; 2668425d6aaSEric W. Biederman } 2678425d6aaSEric W. Biederman 2681f87f0b5SEric W. Biederman /* called under sysctl_lock */ 2691f87f0b5SEric W. Biederman static int use_table(struct ctl_table_header *p) 2701f87f0b5SEric W. Biederman { 2711f87f0b5SEric W. Biederman if (unlikely(p->unregistering)) 2721f87f0b5SEric W. Biederman return 0; 2731f87f0b5SEric W. Biederman p->used++; 2741f87f0b5SEric W. Biederman return 1; 2751f87f0b5SEric W. Biederman } 2761f87f0b5SEric W. Biederman 2771f87f0b5SEric W. Biederman /* called under sysctl_lock */ 2781f87f0b5SEric W. Biederman static void unuse_table(struct ctl_table_header *p) 2791f87f0b5SEric W. Biederman { 2801f87f0b5SEric W. Biederman if (!--p->used) 2811f87f0b5SEric W. Biederman if (unlikely(p->unregistering)) 2821f87f0b5SEric W. Biederman complete(p->unregistering); 2831f87f0b5SEric W. Biederman } 2841f87f0b5SEric W. Biederman 285f90f3cafSEric W. Biederman static void proc_sys_invalidate_dcache(struct ctl_table_header *head) 286d6cffbbeSKonstantin Khlebnikov { 287f90f3cafSEric W. Biederman proc_invalidate_siblings_dcache(&head->inodes, &sysctl_lock); 288d6cffbbeSKonstantin Khlebnikov } 289d6cffbbeSKonstantin Khlebnikov 2901f87f0b5SEric W. Biederman /* called under sysctl_lock, will reacquire if has to wait */ 2911f87f0b5SEric W. Biederman static void start_unregistering(struct ctl_table_header *p) 2921f87f0b5SEric W. Biederman { 2931f87f0b5SEric W. Biederman /* 2941f87f0b5SEric W. Biederman * if p->used is 0, nobody will ever touch that entry again; 2951f87f0b5SEric W. Biederman * we'll eliminate all paths to it before dropping sysctl_lock 2961f87f0b5SEric W. Biederman */ 2971f87f0b5SEric W. Biederman if (unlikely(p->used)) { 2981f87f0b5SEric W. Biederman struct completion wait; 2991f87f0b5SEric W. Biederman init_completion(&wait); 3001f87f0b5SEric W. Biederman p->unregistering = &wait; 3011f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 3021f87f0b5SEric W. Biederman wait_for_completion(&wait); 3031f87f0b5SEric W. Biederman } else { 3041f87f0b5SEric W. Biederman /* anything non-NULL; we'll never dereference it */ 3051f87f0b5SEric W. Biederman p->unregistering = ERR_PTR(-EINVAL); 306ace0c791SEric W. Biederman spin_unlock(&sysctl_lock); 3071f87f0b5SEric W. Biederman } 3081f87f0b5SEric W. Biederman /* 309f90f3cafSEric W. Biederman * Invalidate dentries for unregistered sysctls: namespaced sysctls 310d6cffbbeSKonstantin Khlebnikov * can have duplicate names and contaminate dcache very badly. 311d6cffbbeSKonstantin Khlebnikov */ 312f90f3cafSEric W. Biederman proc_sys_invalidate_dcache(p); 313d6cffbbeSKonstantin Khlebnikov /* 3141f87f0b5SEric W. Biederman * do not remove from the list until nobody holds it; walking the 3151f87f0b5SEric W. Biederman * list in do_sysctl() relies on that. 3161f87f0b5SEric W. Biederman */ 317ace0c791SEric W. Biederman spin_lock(&sysctl_lock); 3188425d6aaSEric W. Biederman erase_header(p); 3191f87f0b5SEric W. Biederman } 3201f87f0b5SEric W. Biederman 3211f87f0b5SEric W. Biederman static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) 3221f87f0b5SEric W. Biederman { 323ab4a1f24SPrasad Joshi BUG_ON(!head); 3241f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 3251f87f0b5SEric W. Biederman if (!use_table(head)) 3261f87f0b5SEric W. Biederman head = ERR_PTR(-ENOENT); 3271f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 3281f87f0b5SEric W. Biederman return head; 3291f87f0b5SEric W. Biederman } 3301f87f0b5SEric W. Biederman 3311f87f0b5SEric W. Biederman static void sysctl_head_finish(struct ctl_table_header *head) 3321f87f0b5SEric W. Biederman { 3331f87f0b5SEric W. Biederman if (!head) 3341f87f0b5SEric W. Biederman return; 3351f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 3361f87f0b5SEric W. Biederman unuse_table(head); 3371f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 3381f87f0b5SEric W. Biederman } 3391f87f0b5SEric W. Biederman 3401f87f0b5SEric W. Biederman static struct ctl_table_set * 34113bcc6a2SEric W. Biederman lookup_header_set(struct ctl_table_root *root) 3421f87f0b5SEric W. Biederman { 3431f87f0b5SEric W. Biederman struct ctl_table_set *set = &root->default_set; 3441f87f0b5SEric W. Biederman if (root->lookup) 34513bcc6a2SEric W. Biederman set = root->lookup(root); 3461f87f0b5SEric W. Biederman return set; 3471f87f0b5SEric W. Biederman } 3481f87f0b5SEric W. Biederman 349076c3eedSEric W. Biederman static struct ctl_table *lookup_entry(struct ctl_table_header **phead, 3507ec66d06SEric W. Biederman struct ctl_dir *dir, 351076c3eedSEric W. Biederman const char *name, int namelen) 352076c3eedSEric W. Biederman { 353076c3eedSEric W. Biederman struct ctl_table_header *head; 354076c3eedSEric W. Biederman struct ctl_table *entry; 355076c3eedSEric W. Biederman 356076c3eedSEric W. Biederman spin_lock(&sysctl_lock); 3570e47c99dSEric W. Biederman entry = find_entry(&head, dir, name, namelen); 358076c3eedSEric W. Biederman if (entry && use_table(head)) 359076c3eedSEric W. Biederman *phead = head; 360076c3eedSEric W. Biederman else 361076c3eedSEric W. Biederman entry = NULL; 362076c3eedSEric W. Biederman spin_unlock(&sysctl_lock); 363076c3eedSEric W. Biederman return entry; 364076c3eedSEric W. Biederman } 365076c3eedSEric W. Biederman 366ac13ac6fSEric W. Biederman static struct ctl_node *first_usable_entry(struct rb_node *node) 3671f87f0b5SEric W. Biederman { 368ac13ac6fSEric W. Biederman struct ctl_node *ctl_node; 3691f87f0b5SEric W. Biederman 370ac13ac6fSEric W. Biederman for (;node; node = rb_next(node)) { 371ac13ac6fSEric W. Biederman ctl_node = rb_entry(node, struct ctl_node, node); 372ac13ac6fSEric W. Biederman if (use_table(ctl_node->header)) 373ac13ac6fSEric W. Biederman return ctl_node; 3741f87f0b5SEric W. Biederman } 3751f87f0b5SEric W. Biederman return NULL; 3761f87f0b5SEric W. Biederman } 3771f87f0b5SEric W. Biederman 3787ec66d06SEric W. Biederman static void first_entry(struct ctl_dir *dir, 3796a75ce16SEric W. Biederman struct ctl_table_header **phead, struct ctl_table **pentry) 3801f87f0b5SEric W. Biederman { 381ac13ac6fSEric W. Biederman struct ctl_table_header *head = NULL; 3827ec66d06SEric W. Biederman struct ctl_table *entry = NULL; 383ac13ac6fSEric W. Biederman struct ctl_node *ctl_node; 3846a75ce16SEric W. Biederman 3856a75ce16SEric W. Biederman spin_lock(&sysctl_lock); 386ac13ac6fSEric W. Biederman ctl_node = first_usable_entry(rb_first(&dir->root)); 3876a75ce16SEric W. Biederman spin_unlock(&sysctl_lock); 388ac13ac6fSEric W. Biederman if (ctl_node) { 389ac13ac6fSEric W. Biederman head = ctl_node->header; 390ac13ac6fSEric W. Biederman entry = &head->ctl_table[ctl_node - head->node]; 391ac13ac6fSEric W. Biederman } 3926a75ce16SEric W. Biederman *phead = head; 3936a75ce16SEric W. Biederman *pentry = entry; 3946a75ce16SEric W. Biederman } 3956a75ce16SEric W. Biederman 3967ec66d06SEric W. Biederman static void next_entry(struct ctl_table_header **phead, struct ctl_table **pentry) 3976a75ce16SEric W. Biederman { 3986a75ce16SEric W. Biederman struct ctl_table_header *head = *phead; 3996a75ce16SEric W. Biederman struct ctl_table *entry = *pentry; 400ac13ac6fSEric W. Biederman struct ctl_node *ctl_node = &head->node[entry - head->ctl_table]; 4016a75ce16SEric W. Biederman 4026a75ce16SEric W. Biederman spin_lock(&sysctl_lock); 4036a75ce16SEric W. Biederman unuse_table(head); 404ac13ac6fSEric W. Biederman 405ac13ac6fSEric W. Biederman ctl_node = first_usable_entry(rb_next(&ctl_node->node)); 4066a75ce16SEric W. Biederman spin_unlock(&sysctl_lock); 407ac13ac6fSEric W. Biederman head = NULL; 408ac13ac6fSEric W. Biederman if (ctl_node) { 409ac13ac6fSEric W. Biederman head = ctl_node->header; 410ac13ac6fSEric W. Biederman entry = &head->ctl_table[ctl_node - head->node]; 4116a75ce16SEric W. Biederman } 4126a75ce16SEric W. Biederman *phead = head; 4136a75ce16SEric W. Biederman *pentry = entry; 4141f87f0b5SEric W. Biederman } 4151f87f0b5SEric W. Biederman 4161f87f0b5SEric W. Biederman /* 4171f87f0b5SEric W. Biederman * sysctl_perm does NOT grant the superuser all rights automatically, because 4181f87f0b5SEric W. Biederman * some sysctl variables are readonly even to root. 4191f87f0b5SEric W. Biederman */ 4201f87f0b5SEric W. Biederman 4211f87f0b5SEric W. Biederman static int test_perm(int mode, int op) 4221f87f0b5SEric W. Biederman { 423091bd3eaSEric W. Biederman if (uid_eq(current_euid(), GLOBAL_ROOT_UID)) 4241f87f0b5SEric W. Biederman mode >>= 6; 425091bd3eaSEric W. Biederman else if (in_egroup_p(GLOBAL_ROOT_GID)) 4261f87f0b5SEric W. Biederman mode >>= 3; 4271f87f0b5SEric W. Biederman if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) 4281f87f0b5SEric W. Biederman return 0; 4291f87f0b5SEric W. Biederman return -EACCES; 4301f87f0b5SEric W. Biederman } 4311f87f0b5SEric W. Biederman 43273f7ef43SEric W. Biederman static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, int op) 4331f87f0b5SEric W. Biederman { 43473f7ef43SEric W. Biederman struct ctl_table_root *root = head->root; 4351f87f0b5SEric W. Biederman int mode; 4361f87f0b5SEric W. Biederman 4371f87f0b5SEric W. Biederman if (root->permissions) 43873f7ef43SEric W. Biederman mode = root->permissions(head, table); 4391f87f0b5SEric W. Biederman else 4401f87f0b5SEric W. Biederman mode = table->mode; 4411f87f0b5SEric W. Biederman 4421f87f0b5SEric W. Biederman return test_perm(mode, op); 4431f87f0b5SEric W. Biederman } 4441f87f0b5SEric W. Biederman 4459043476fSAl Viro static struct inode *proc_sys_make_inode(struct super_block *sb, 4469043476fSAl Viro struct ctl_table_header *head, struct ctl_table *table) 44777b14db5SEric W. Biederman { 448e79c6a4fSDmitry Torokhov struct ctl_table_root *root = head->root; 44977b14db5SEric W. Biederman struct inode *inode; 4509043476fSAl Viro struct proc_inode *ei; 45177b14db5SEric W. Biederman 4529043476fSAl Viro inode = new_inode(sb); 45377b14db5SEric W. Biederman if (!inode) 454ea5751ccSIvan Delalande return ERR_PTR(-ENOMEM); 45577b14db5SEric W. Biederman 45685fe4025SChristoph Hellwig inode->i_ino = get_next_ino(); 45785fe4025SChristoph Hellwig 45877b14db5SEric W. Biederman ei = PROC_I(inode); 4599043476fSAl Viro 460d6cffbbeSKonstantin Khlebnikov spin_lock(&sysctl_lock); 461ace0c791SEric W. Biederman if (unlikely(head->unregistering)) { 462ace0c791SEric W. Biederman spin_unlock(&sysctl_lock); 463ace0c791SEric W. Biederman iput(inode); 464ea5751ccSIvan Delalande return ERR_PTR(-ENOENT); 465ace0c791SEric W. Biederman } 466ace0c791SEric W. Biederman ei->sysctl = head; 467ace0c791SEric W. Biederman ei->sysctl_entry = table; 4680afa5ca8SEric W. Biederman hlist_add_head_rcu(&ei->sibling_inodes, &head->inodes); 469d6cffbbeSKonstantin Khlebnikov head->count++; 470d6cffbbeSKonstantin Khlebnikov spin_unlock(&sysctl_lock); 471d6cffbbeSKonstantin Khlebnikov 472078cd827SDeepa Dinamani inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 4739043476fSAl Viro inode->i_mode = table->mode; 4747ec66d06SEric W. Biederman if (!S_ISDIR(table->mode)) { 4759043476fSAl Viro inode->i_mode |= S_IFREG; 47677b14db5SEric W. Biederman inode->i_op = &proc_sys_inode_operations; 47777b14db5SEric W. Biederman inode->i_fop = &proc_sys_file_operations; 4789043476fSAl Viro } else { 4799043476fSAl Viro inode->i_mode |= S_IFDIR; 4809043476fSAl Viro inode->i_op = &proc_sys_dir_operations; 4819043476fSAl Viro inode->i_fop = &proc_sys_dir_file_operations; 482f9bd6733SEric W. Biederman if (is_empty_dir(head)) 483f9bd6733SEric W. Biederman make_empty_dir_inode(inode); 4849043476fSAl Viro } 485e79c6a4fSDmitry Torokhov 486e79c6a4fSDmitry Torokhov if (root->set_ownership) 487e79c6a4fSDmitry Torokhov root->set_ownership(head, table, &inode->i_uid, &inode->i_gid); 4885ec27ec7SRadoslaw Burny else { 4895ec27ec7SRadoslaw Burny inode->i_uid = GLOBAL_ROOT_UID; 4905ec27ec7SRadoslaw Burny inode->i_gid = GLOBAL_ROOT_GID; 4915ec27ec7SRadoslaw Burny } 492e79c6a4fSDmitry Torokhov 49377b14db5SEric W. Biederman return inode; 49477b14db5SEric W. Biederman } 49577b14db5SEric W. Biederman 496d6cffbbeSKonstantin Khlebnikov void proc_sys_evict_inode(struct inode *inode, struct ctl_table_header *head) 497d6cffbbeSKonstantin Khlebnikov { 498d6cffbbeSKonstantin Khlebnikov spin_lock(&sysctl_lock); 4990afa5ca8SEric W. Biederman hlist_del_init_rcu(&PROC_I(inode)->sibling_inodes); 500d6cffbbeSKonstantin Khlebnikov if (!--head->count) 501d6cffbbeSKonstantin Khlebnikov kfree_rcu(head, rcu); 502d6cffbbeSKonstantin Khlebnikov spin_unlock(&sysctl_lock); 503d6cffbbeSKonstantin Khlebnikov } 504d6cffbbeSKonstantin Khlebnikov 50581324364SAdrian Bunk static struct ctl_table_header *grab_header(struct inode *inode) 50677b14db5SEric W. Biederman { 5073cc3e046SEric W. Biederman struct ctl_table_header *head = PROC_I(inode)->sysctl; 5083cc3e046SEric W. Biederman if (!head) 5090e47c99dSEric W. Biederman head = &sysctl_table_root.default_set.dir.header; 5103cc3e046SEric W. Biederman return sysctl_head_grab(head); 51177b14db5SEric W. Biederman } 51277b14db5SEric W. Biederman 51377b14db5SEric W. Biederman static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, 51400cd8dd3SAl Viro unsigned int flags) 51577b14db5SEric W. Biederman { 5169043476fSAl Viro struct ctl_table_header *head = grab_header(dir); 5179043476fSAl Viro struct ctl_table_header *h = NULL; 518dc12e909SAl Viro const struct qstr *name = &dentry->d_name; 5199043476fSAl Viro struct ctl_table *p; 52077b14db5SEric W. Biederman struct inode *inode; 5219043476fSAl Viro struct dentry *err = ERR_PTR(-ENOENT); 5227ec66d06SEric W. Biederman struct ctl_dir *ctl_dir; 5230e47c99dSEric W. Biederman int ret; 52477b14db5SEric W. Biederman 5259043476fSAl Viro if (IS_ERR(head)) 5269043476fSAl Viro return ERR_CAST(head); 5279043476fSAl Viro 5287ec66d06SEric W. Biederman ctl_dir = container_of(head, struct ctl_dir, header); 5299043476fSAl Viro 5307ec66d06SEric W. Biederman p = lookup_entry(&h, ctl_dir, name->name, name->len); 5319043476fSAl Viro if (!p) 53277b14db5SEric W. Biederman goto out; 53377b14db5SEric W. Biederman 5344e757320SEric W. Biederman if (S_ISLNK(p->mode)) { 53513bcc6a2SEric W. Biederman ret = sysctl_follow_link(&h, &p); 5360e47c99dSEric W. Biederman err = ERR_PTR(ret); 5370e47c99dSEric W. Biederman if (ret) 5380e47c99dSEric W. Biederman goto out; 5394e757320SEric W. Biederman } 5400e47c99dSEric W. Biederman 5419043476fSAl Viro inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); 542ea5751ccSIvan Delalande if (IS_ERR(inode)) { 543ea5751ccSIvan Delalande err = ERR_CAST(inode); 54477b14db5SEric W. Biederman goto out; 545ea5751ccSIvan Delalande } 54677b14db5SEric W. Biederman 547fb045adbSNick Piggin d_set_d_op(dentry, &proc_sys_dentry_operations); 548888e2b03SAl Viro err = d_splice_alias(inode, dentry); 54977b14db5SEric W. Biederman 55077b14db5SEric W. Biederman out: 5516bf61045SFrancesco Ruggeri if (h) 5526bf61045SFrancesco Ruggeri sysctl_head_finish(h); 55377b14db5SEric W. Biederman sysctl_head_finish(head); 55477b14db5SEric W. Biederman return err; 55577b14db5SEric W. Biederman } 55677b14db5SEric W. Biederman 5574bd6a735SMatthew Wilcox (Oracle) static ssize_t proc_sys_call_handler(struct kiocb *iocb, struct iov_iter *iter, 5584bd6a735SMatthew Wilcox (Oracle) int write) 55977b14db5SEric W. Biederman { 5604bd6a735SMatthew Wilcox (Oracle) struct inode *inode = file_inode(iocb->ki_filp); 5619043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 5629043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 5634bd6a735SMatthew Wilcox (Oracle) size_t count = iov_iter_count(iter); 5644bd6a735SMatthew Wilcox (Oracle) char *kbuf; 5652a2da53bSDavid Howells ssize_t error; 56677b14db5SEric W. Biederman 5679043476fSAl Viro if (IS_ERR(head)) 5689043476fSAl Viro return PTR_ERR(head); 56977b14db5SEric W. Biederman 57077b14db5SEric W. Biederman /* 57177b14db5SEric W. Biederman * At this point we know that the sysctl was not unregistered 57277b14db5SEric W. Biederman * and won't be until we finish. 57377b14db5SEric W. Biederman */ 57477b14db5SEric W. Biederman error = -EPERM; 57573f7ef43SEric W. Biederman if (sysctl_perm(head, table, write ? MAY_WRITE : MAY_READ)) 57677b14db5SEric W. Biederman goto out; 57777b14db5SEric W. Biederman 5789043476fSAl Viro /* if that can happen at all, it should be -EINVAL, not -EISDIR */ 5799043476fSAl Viro error = -EINVAL; 5809043476fSAl Viro if (!table->proc_handler) 5819043476fSAl Viro goto out; 5829043476fSAl Viro 583ef9d965bSChristoph Hellwig /* don't even try if the size is too large */ 584d4d80e69SMatthew Wilcox (Oracle) error = -ENOMEM; 585d4d80e69SMatthew Wilcox (Oracle) if (count >= KMALLOC_MAX_SIZE) 586d4d80e69SMatthew Wilcox (Oracle) goto out; 58745089437SJosef Bacik kbuf = kvzalloc(count + 1, GFP_KERNEL); 58832927393SChristoph Hellwig if (!kbuf) 58932927393SChristoph Hellwig goto out; 5904bd6a735SMatthew Wilcox (Oracle) 5914bd6a735SMatthew Wilcox (Oracle) if (write) { 5924bd6a735SMatthew Wilcox (Oracle) error = -EFAULT; 5934bd6a735SMatthew Wilcox (Oracle) if (!copy_from_iter_full(kbuf, count, iter)) 5944bd6a735SMatthew Wilcox (Oracle) goto out_free_buf; 5954bd6a735SMatthew Wilcox (Oracle) kbuf[count] = '\0'; 5964e63acdfSAndrey Ignatov } 5974e63acdfSAndrey Ignatov 59832927393SChristoph Hellwig error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, &kbuf, &count, 5994bd6a735SMatthew Wilcox (Oracle) &iocb->ki_pos); 60032927393SChristoph Hellwig if (error) 60132927393SChristoph Hellwig goto out_free_buf; 60232927393SChristoph Hellwig 60332927393SChristoph Hellwig /* careful: calling conventions are nasty here */ 6044bd6a735SMatthew Wilcox (Oracle) error = table->proc_handler(table, write, kbuf, &count, &iocb->ki_pos); 60532927393SChristoph Hellwig if (error) 60632927393SChristoph Hellwig goto out_free_buf; 60732927393SChristoph Hellwig 60832927393SChristoph Hellwig if (!write) { 60932927393SChristoph Hellwig error = -EFAULT; 6104bd6a735SMatthew Wilcox (Oracle) if (copy_to_iter(kbuf, count, iter) < count) 61132927393SChristoph Hellwig goto out_free_buf; 61232927393SChristoph Hellwig } 61332927393SChristoph Hellwig 6144e63acdfSAndrey Ignatov error = count; 61532927393SChristoph Hellwig out_free_buf: 61645089437SJosef Bacik kvfree(kbuf); 61777b14db5SEric W. Biederman out: 61877b14db5SEric W. Biederman sysctl_head_finish(head); 61977b14db5SEric W. Biederman 62077b14db5SEric W. Biederman return error; 62177b14db5SEric W. Biederman } 62277b14db5SEric W. Biederman 6234bd6a735SMatthew Wilcox (Oracle) static ssize_t proc_sys_read(struct kiocb *iocb, struct iov_iter *iter) 6247708bfb1SPavel Emelyanov { 6254bd6a735SMatthew Wilcox (Oracle) return proc_sys_call_handler(iocb, iter, 0); 6267708bfb1SPavel Emelyanov } 6277708bfb1SPavel Emelyanov 6284bd6a735SMatthew Wilcox (Oracle) static ssize_t proc_sys_write(struct kiocb *iocb, struct iov_iter *iter) 62977b14db5SEric W. Biederman { 6304bd6a735SMatthew Wilcox (Oracle) return proc_sys_call_handler(iocb, iter, 1); 63177b14db5SEric W. Biederman } 63277b14db5SEric W. Biederman 633f1ecf068SLucas De Marchi static int proc_sys_open(struct inode *inode, struct file *filp) 634f1ecf068SLucas De Marchi { 6354e474a00SLucas De Marchi struct ctl_table_header *head = grab_header(inode); 636f1ecf068SLucas De Marchi struct ctl_table *table = PROC_I(inode)->sysctl_entry; 637f1ecf068SLucas De Marchi 6384e474a00SLucas De Marchi /* sysctl was unregistered */ 6394e474a00SLucas De Marchi if (IS_ERR(head)) 6404e474a00SLucas De Marchi return PTR_ERR(head); 6414e474a00SLucas De Marchi 642f1ecf068SLucas De Marchi if (table->poll) 643f1ecf068SLucas De Marchi filp->private_data = proc_sys_poll_event(table->poll); 644f1ecf068SLucas De Marchi 6454e474a00SLucas De Marchi sysctl_head_finish(head); 6464e474a00SLucas De Marchi 647f1ecf068SLucas De Marchi return 0; 648f1ecf068SLucas De Marchi } 649f1ecf068SLucas De Marchi 650076ccb76SAl Viro static __poll_t proc_sys_poll(struct file *filp, poll_table *wait) 651f1ecf068SLucas De Marchi { 652496ad9aaSAl Viro struct inode *inode = file_inode(filp); 6534e474a00SLucas De Marchi struct ctl_table_header *head = grab_header(inode); 654f1ecf068SLucas De Marchi struct ctl_table *table = PROC_I(inode)->sysctl_entry; 655076ccb76SAl Viro __poll_t ret = DEFAULT_POLLMASK; 6564e474a00SLucas De Marchi unsigned long event; 6574e474a00SLucas De Marchi 6584e474a00SLucas De Marchi /* sysctl was unregistered */ 6594e474a00SLucas De Marchi if (IS_ERR(head)) 660a9a08845SLinus Torvalds return EPOLLERR | EPOLLHUP; 661f1ecf068SLucas De Marchi 662f1ecf068SLucas De Marchi if (!table->proc_handler) 663f1ecf068SLucas De Marchi goto out; 664f1ecf068SLucas De Marchi 665f1ecf068SLucas De Marchi if (!table->poll) 666f1ecf068SLucas De Marchi goto out; 667f1ecf068SLucas De Marchi 6684e474a00SLucas De Marchi event = (unsigned long)filp->private_data; 669f1ecf068SLucas De Marchi poll_wait(filp, &table->poll->wait, wait); 670f1ecf068SLucas De Marchi 671f1ecf068SLucas De Marchi if (event != atomic_read(&table->poll->event)) { 672f1ecf068SLucas De Marchi filp->private_data = proc_sys_poll_event(table->poll); 673a9a08845SLinus Torvalds ret = EPOLLIN | EPOLLRDNORM | EPOLLERR | EPOLLPRI; 674f1ecf068SLucas De Marchi } 675f1ecf068SLucas De Marchi 676f1ecf068SLucas De Marchi out: 6774e474a00SLucas De Marchi sysctl_head_finish(head); 6784e474a00SLucas De Marchi 679f1ecf068SLucas De Marchi return ret; 680f1ecf068SLucas De Marchi } 68177b14db5SEric W. Biederman 682f0c3b509SAl Viro static bool proc_sys_fill_cache(struct file *file, 683f0c3b509SAl Viro struct dir_context *ctx, 6849043476fSAl Viro struct ctl_table_header *head, 6859043476fSAl Viro struct ctl_table *table) 68677b14db5SEric W. Biederman { 687f0c3b509SAl Viro struct dentry *child, *dir = file->f_path.dentry; 68877b14db5SEric W. Biederman struct inode *inode; 68977b14db5SEric W. Biederman struct qstr qname; 69077b14db5SEric W. Biederman ino_t ino = 0; 69177b14db5SEric W. Biederman unsigned type = DT_UNKNOWN; 69277b14db5SEric W. Biederman 69377b14db5SEric W. Biederman qname.name = table->procname; 69477b14db5SEric W. Biederman qname.len = strlen(table->procname); 6958387ff25SLinus Torvalds qname.hash = full_name_hash(dir, qname.name, qname.len); 69677b14db5SEric W. Biederman 69777b14db5SEric W. Biederman child = d_lookup(dir, &qname); 69877b14db5SEric W. Biederman if (!child) { 69976aab3abSAl Viro DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 70076aab3abSAl Viro child = d_alloc_parallel(dir, &qname, &wq); 70176aab3abSAl Viro if (IS_ERR(child)) 70276aab3abSAl Viro return false; 70376aab3abSAl Viro if (d_in_lookup(child)) { 704888e2b03SAl Viro struct dentry *res; 7059043476fSAl Viro inode = proc_sys_make_inode(dir->d_sb, head, table); 706ea5751ccSIvan Delalande if (IS_ERR(inode)) { 70776aab3abSAl Viro d_lookup_done(child); 7089043476fSAl Viro dput(child); 709f0c3b509SAl Viro return false; 71076aab3abSAl Viro } 711fb045adbSNick Piggin d_set_d_op(child, &proc_sys_dentry_operations); 712888e2b03SAl Viro res = d_splice_alias(inode, child); 713888e2b03SAl Viro d_lookup_done(child); 714888e2b03SAl Viro if (unlikely(res)) { 715888e2b03SAl Viro if (IS_ERR(res)) { 716888e2b03SAl Viro dput(child); 717888e2b03SAl Viro return false; 718888e2b03SAl Viro } 719888e2b03SAl Viro dput(child); 720888e2b03SAl Viro child = res; 721888e2b03SAl Viro } 72277b14db5SEric W. Biederman } 72377b14db5SEric W. Biederman } 7242b0143b5SDavid Howells inode = d_inode(child); 72577b14db5SEric W. Biederman ino = inode->i_ino; 72677b14db5SEric W. Biederman type = inode->i_mode >> 12; 72777b14db5SEric W. Biederman dput(child); 728f0c3b509SAl Viro return dir_emit(ctx, qname.name, qname.len, ino, type); 7299043476fSAl Viro } 7309043476fSAl Viro 731f0c3b509SAl Viro static bool proc_sys_link_fill_cache(struct file *file, 732f0c3b509SAl Viro struct dir_context *ctx, 7330e47c99dSEric W. Biederman struct ctl_table_header *head, 7340e47c99dSEric W. Biederman struct ctl_table *table) 7350e47c99dSEric W. Biederman { 736f0c3b509SAl Viro bool ret = true; 737a0b0d1c3SDanilo Krummrich 7380e47c99dSEric W. Biederman head = sysctl_head_grab(head); 739a0b0d1c3SDanilo Krummrich if (IS_ERR(head)) 740a0b0d1c3SDanilo Krummrich return false; 7410e47c99dSEric W. Biederman 7420e47c99dSEric W. Biederman /* It is not an error if we can not follow the link ignore it */ 743835b94e0SDanilo Krummrich if (sysctl_follow_link(&head, &table)) 7440e47c99dSEric W. Biederman goto out; 7450e47c99dSEric W. Biederman 746f0c3b509SAl Viro ret = proc_sys_fill_cache(file, ctx, head, table); 7470e47c99dSEric W. Biederman out: 7480e47c99dSEric W. Biederman sysctl_head_finish(head); 7490e47c99dSEric W. Biederman return ret; 7500e47c99dSEric W. Biederman } 7510e47c99dSEric W. Biederman 752e5eea098SJoe Perches static int scan(struct ctl_table_header *head, struct ctl_table *table, 7539043476fSAl Viro unsigned long *pos, struct file *file, 754f0c3b509SAl Viro struct dir_context *ctx) 7559043476fSAl Viro { 756f0c3b509SAl Viro bool res; 7579043476fSAl Viro 758f0c3b509SAl Viro if ((*pos)++ < ctx->pos) 759f0c3b509SAl Viro return true; 7609043476fSAl Viro 7610e47c99dSEric W. Biederman if (unlikely(S_ISLNK(table->mode))) 762f0c3b509SAl Viro res = proc_sys_link_fill_cache(file, ctx, head, table); 7630e47c99dSEric W. Biederman else 764f0c3b509SAl Viro res = proc_sys_fill_cache(file, ctx, head, table); 7659043476fSAl Viro 766f0c3b509SAl Viro if (res) 767f0c3b509SAl Viro ctx->pos = *pos; 7686a75ce16SEric W. Biederman 7696a75ce16SEric W. Biederman return res; 77077b14db5SEric W. Biederman } 77177b14db5SEric W. Biederman 772f0c3b509SAl Viro static int proc_sys_readdir(struct file *file, struct dir_context *ctx) 77377b14db5SEric W. Biederman { 774f0c3b509SAl Viro struct ctl_table_header *head = grab_header(file_inode(file)); 7759043476fSAl Viro struct ctl_table_header *h = NULL; 7766a75ce16SEric W. Biederman struct ctl_table *entry; 7777ec66d06SEric W. Biederman struct ctl_dir *ctl_dir; 77877b14db5SEric W. Biederman unsigned long pos; 77977b14db5SEric W. Biederman 7809043476fSAl Viro if (IS_ERR(head)) 7819043476fSAl Viro return PTR_ERR(head); 7829043476fSAl Viro 7837ec66d06SEric W. Biederman ctl_dir = container_of(head, struct ctl_dir, header); 78477b14db5SEric W. Biederman 785f0c3b509SAl Viro if (!dir_emit_dots(file, ctx)) 78693362fa4SZhou Chengming goto out; 787f0c3b509SAl Viro 78877b14db5SEric W. Biederman pos = 2; 78977b14db5SEric W. Biederman 7907ec66d06SEric W. Biederman for (first_entry(ctl_dir, &h, &entry); h; next_entry(&h, &entry)) { 791f0c3b509SAl Viro if (!scan(h, entry, &pos, file, ctx)) { 7929043476fSAl Viro sysctl_head_finish(h); 7939043476fSAl Viro break; 79477b14db5SEric W. Biederman } 79577b14db5SEric W. Biederman } 79693362fa4SZhou Chengming out: 79777b14db5SEric W. Biederman sysctl_head_finish(head); 798f0c3b509SAl Viro return 0; 79977b14db5SEric W. Biederman } 80077b14db5SEric W. Biederman 801549c7297SChristian Brauner static int proc_sys_permission(struct user_namespace *mnt_userns, 802549c7297SChristian Brauner struct inode *inode, int mask) 80377b14db5SEric W. Biederman { 80477b14db5SEric W. Biederman /* 80577b14db5SEric W. Biederman * sysctl entries that are not writeable, 80677b14db5SEric W. Biederman * are _NOT_ writeable, capabilities or not. 80777b14db5SEric W. Biederman */ 808f696a365SMiklos Szeredi struct ctl_table_header *head; 809f696a365SMiklos Szeredi struct ctl_table *table; 81077b14db5SEric W. Biederman int error; 81177b14db5SEric W. Biederman 812f696a365SMiklos Szeredi /* Executable files are not allowed under /proc/sys/ */ 813f696a365SMiklos Szeredi if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) 814f696a365SMiklos Szeredi return -EACCES; 815f696a365SMiklos Szeredi 816f696a365SMiklos Szeredi head = grab_header(inode); 8179043476fSAl Viro if (IS_ERR(head)) 8189043476fSAl Viro return PTR_ERR(head); 81977b14db5SEric W. Biederman 820f696a365SMiklos Szeredi table = PROC_I(inode)->sysctl_entry; 8219043476fSAl Viro if (!table) /* global root - r-xr-xr-x */ 8229043476fSAl Viro error = mask & MAY_WRITE ? -EACCES : 0; 8239043476fSAl Viro else /* Use the permissions on the sysctl table entry */ 82473f7ef43SEric W. Biederman error = sysctl_perm(head, table, mask & ~MAY_NOT_BLOCK); 8259043476fSAl Viro 82677b14db5SEric W. Biederman sysctl_head_finish(head); 82777b14db5SEric W. Biederman return error; 82877b14db5SEric W. Biederman } 82977b14db5SEric W. Biederman 830549c7297SChristian Brauner static int proc_sys_setattr(struct user_namespace *mnt_userns, 831549c7297SChristian Brauner struct dentry *dentry, struct iattr *attr) 83277b14db5SEric W. Biederman { 8332b0143b5SDavid Howells struct inode *inode = d_inode(dentry); 83477b14db5SEric W. Biederman int error; 83577b14db5SEric W. Biederman 83677b14db5SEric W. Biederman if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) 83777b14db5SEric W. Biederman return -EPERM; 83877b14db5SEric W. Biederman 8392f221d6fSChristian Brauner error = setattr_prepare(&init_user_ns, dentry, attr); 8401025774cSChristoph Hellwig if (error) 84177b14db5SEric W. Biederman return error; 8421025774cSChristoph Hellwig 8432f221d6fSChristian Brauner setattr_copy(&init_user_ns, inode, attr); 8441025774cSChristoph Hellwig mark_inode_dirty(inode); 8451025774cSChristoph Hellwig return 0; 84677b14db5SEric W. Biederman } 84777b14db5SEric W. Biederman 848549c7297SChristian Brauner static int proc_sys_getattr(struct user_namespace *mnt_userns, 849549c7297SChristian Brauner const struct path *path, struct kstat *stat, 850a528d35eSDavid Howells u32 request_mask, unsigned int query_flags) 8519043476fSAl Viro { 852a528d35eSDavid Howells struct inode *inode = d_inode(path->dentry); 8539043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 8549043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 8559043476fSAl Viro 8569043476fSAl Viro if (IS_ERR(head)) 8579043476fSAl Viro return PTR_ERR(head); 8589043476fSAl Viro 8590d56a451SChristian Brauner generic_fillattr(&init_user_ns, inode, stat); 8609043476fSAl Viro if (table) 8619043476fSAl Viro stat->mode = (stat->mode & S_IFMT) | table->mode; 8629043476fSAl Viro 8639043476fSAl Viro sysctl_head_finish(head); 8649043476fSAl Viro return 0; 8659043476fSAl Viro } 8669043476fSAl Viro 86777b14db5SEric W. Biederman static const struct file_operations proc_sys_file_operations = { 868f1ecf068SLucas De Marchi .open = proc_sys_open, 869f1ecf068SLucas De Marchi .poll = proc_sys_poll, 8704bd6a735SMatthew Wilcox (Oracle) .read_iter = proc_sys_read, 8714bd6a735SMatthew Wilcox (Oracle) .write_iter = proc_sys_write, 8724bd6a735SMatthew Wilcox (Oracle) .splice_read = generic_file_splice_read, 8734bd6a735SMatthew Wilcox (Oracle) .splice_write = iter_file_splice_write, 8746038f373SArnd Bergmann .llseek = default_llseek, 8759043476fSAl Viro }; 8769043476fSAl Viro 8779043476fSAl Viro static const struct file_operations proc_sys_dir_file_operations = { 878887df078SPavel Emelyanov .read = generic_read_dir, 879f50752eaSAl Viro .iterate_shared = proc_sys_readdir, 8803222a3e5SChristoph Hellwig .llseek = generic_file_llseek, 88177b14db5SEric W. Biederman }; 88277b14db5SEric W. Biederman 88303a44825SJan Engelhardt static const struct inode_operations proc_sys_inode_operations = { 8849043476fSAl Viro .permission = proc_sys_permission, 8859043476fSAl Viro .setattr = proc_sys_setattr, 8869043476fSAl Viro .getattr = proc_sys_getattr, 8879043476fSAl Viro }; 8889043476fSAl Viro 8899043476fSAl Viro static const struct inode_operations proc_sys_dir_operations = { 89077b14db5SEric W. Biederman .lookup = proc_sys_lookup, 89177b14db5SEric W. Biederman .permission = proc_sys_permission, 89277b14db5SEric W. Biederman .setattr = proc_sys_setattr, 8939043476fSAl Viro .getattr = proc_sys_getattr, 89477b14db5SEric W. Biederman }; 89577b14db5SEric W. Biederman 8960b728e19SAl Viro static int proc_sys_revalidate(struct dentry *dentry, unsigned int flags) 89777b14db5SEric W. Biederman { 8980b728e19SAl Viro if (flags & LOOKUP_RCU) 89934286d66SNick Piggin return -ECHILD; 9002b0143b5SDavid Howells return !PROC_I(d_inode(dentry))->sysctl->unregistering; 9019043476fSAl Viro } 9029043476fSAl Viro 903fe15ce44SNick Piggin static int proc_sys_delete(const struct dentry *dentry) 9049043476fSAl Viro { 9052b0143b5SDavid Howells return !!PROC_I(d_inode(dentry))->sysctl->unregistering; 9069043476fSAl Viro } 9079043476fSAl Viro 9081f87f0b5SEric W. Biederman static int sysctl_is_seen(struct ctl_table_header *p) 9091f87f0b5SEric W. Biederman { 9101f87f0b5SEric W. Biederman struct ctl_table_set *set = p->set; 9111f87f0b5SEric W. Biederman int res; 9121f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 9131f87f0b5SEric W. Biederman if (p->unregistering) 9141f87f0b5SEric W. Biederman res = 0; 9151f87f0b5SEric W. Biederman else if (!set->is_seen) 9161f87f0b5SEric W. Biederman res = 1; 9171f87f0b5SEric W. Biederman else 9181f87f0b5SEric W. Biederman res = set->is_seen(set); 9191f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 9201f87f0b5SEric W. Biederman return res; 9211f87f0b5SEric W. Biederman } 9221f87f0b5SEric W. Biederman 9236fa67e70SAl Viro static int proc_sys_compare(const struct dentry *dentry, 924621e155aSNick Piggin unsigned int len, const char *str, const struct qstr *name) 9259043476fSAl Viro { 926dfef6dcdSAl Viro struct ctl_table_header *head; 927da53be12SLinus Torvalds struct inode *inode; 928da53be12SLinus Torvalds 92931e6b01fSNick Piggin /* Although proc doesn't have negative dentries, rcu-walk means 93031e6b01fSNick Piggin * that inode here can be NULL */ 931dfef6dcdSAl Viro /* AV: can it, indeed? */ 9322b0143b5SDavid Howells inode = d_inode_rcu(dentry); 93331e6b01fSNick Piggin if (!inode) 934dfef6dcdSAl Viro return 1; 935621e155aSNick Piggin if (name->len != len) 9369043476fSAl Viro return 1; 937621e155aSNick Piggin if (memcmp(name->name, str, len)) 9389043476fSAl Viro return 1; 939dfef6dcdSAl Viro head = rcu_dereference(PROC_I(inode)->sysctl); 940dfef6dcdSAl Viro return !head || !sysctl_is_seen(head); 94177b14db5SEric W. Biederman } 94277b14db5SEric W. Biederman 943d72f71ebSAl Viro static const struct dentry_operations proc_sys_dentry_operations = { 94477b14db5SEric W. Biederman .d_revalidate = proc_sys_revalidate, 9459043476fSAl Viro .d_delete = proc_sys_delete, 9469043476fSAl Viro .d_compare = proc_sys_compare, 94777b14db5SEric W. Biederman }; 94877b14db5SEric W. Biederman 9490e47c99dSEric W. Biederman static struct ctl_dir *find_subdir(struct ctl_dir *dir, 9507ec66d06SEric W. Biederman const char *name, int namelen) 9511f87f0b5SEric W. Biederman { 9527ec66d06SEric W. Biederman struct ctl_table_header *head; 9537ec66d06SEric W. Biederman struct ctl_table *entry; 9541f87f0b5SEric W. Biederman 9550e47c99dSEric W. Biederman entry = find_entry(&head, dir, name, namelen); 9567ec66d06SEric W. Biederman if (!entry) 9577ec66d06SEric W. Biederman return ERR_PTR(-ENOENT); 95851f72f4aSEric W. Biederman if (!S_ISDIR(entry->mode)) 9597ec66d06SEric W. Biederman return ERR_PTR(-ENOTDIR); 96051f72f4aSEric W. Biederman return container_of(head, struct ctl_dir, header); 9611f87f0b5SEric W. Biederman } 9621f87f0b5SEric W. Biederman 9637ec66d06SEric W. Biederman static struct ctl_dir *new_dir(struct ctl_table_set *set, 9647ec66d06SEric W. Biederman const char *name, int namelen) 9651f87f0b5SEric W. Biederman { 9667ec66d06SEric W. Biederman struct ctl_table *table; 9677ec66d06SEric W. Biederman struct ctl_dir *new; 968ac13ac6fSEric W. Biederman struct ctl_node *node; 9697ec66d06SEric W. Biederman char *new_name; 9701f87f0b5SEric W. Biederman 971ac13ac6fSEric W. Biederman new = kzalloc(sizeof(*new) + sizeof(struct ctl_node) + 972ac13ac6fSEric W. Biederman sizeof(struct ctl_table)*2 + namelen + 1, 973ac13ac6fSEric W. Biederman GFP_KERNEL); 9747ec66d06SEric W. Biederman if (!new) 9757ec66d06SEric W. Biederman return NULL; 9767ec66d06SEric W. Biederman 977ac13ac6fSEric W. Biederman node = (struct ctl_node *)(new + 1); 978ac13ac6fSEric W. Biederman table = (struct ctl_table *)(node + 1); 9797ec66d06SEric W. Biederman new_name = (char *)(table + 2); 9807ec66d06SEric W. Biederman memcpy(new_name, name, namelen); 9817ec66d06SEric W. Biederman new_name[namelen] = '\0'; 9827ec66d06SEric W. Biederman table[0].procname = new_name; 9837ec66d06SEric W. Biederman table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO; 984ac13ac6fSEric W. Biederman init_header(&new->header, set->dir.header.root, set, node, table); 9857ec66d06SEric W. Biederman 9867ec66d06SEric W. Biederman return new; 9871f87f0b5SEric W. Biederman } 9881f87f0b5SEric W. Biederman 98960f126d9SEric W. Biederman /** 99060f126d9SEric W. Biederman * get_subdir - find or create a subdir with the specified name. 99160f126d9SEric W. Biederman * @dir: Directory to create the subdirectory in 99260f126d9SEric W. Biederman * @name: The name of the subdirectory to find or create 99360f126d9SEric W. Biederman * @namelen: The length of name 99460f126d9SEric W. Biederman * 99560f126d9SEric W. Biederman * Takes a directory with an elevated reference count so we know that 99660f126d9SEric W. Biederman * if we drop the lock the directory will not go away. Upon success 99760f126d9SEric W. Biederman * the reference is moved from @dir to the returned subdirectory. 99860f126d9SEric W. Biederman * Upon error an error code is returned and the reference on @dir is 99960f126d9SEric W. Biederman * simply dropped. 100060f126d9SEric W. Biederman */ 10010e47c99dSEric W. Biederman static struct ctl_dir *get_subdir(struct ctl_dir *dir, 10020e47c99dSEric W. Biederman const char *name, int namelen) 10037ec66d06SEric W. Biederman { 10040e47c99dSEric W. Biederman struct ctl_table_set *set = dir->header.set; 10057ec66d06SEric W. Biederman struct ctl_dir *subdir, *new = NULL; 10060eb97f38SEric W. Biederman int err; 10077ec66d06SEric W. Biederman 10087ec66d06SEric W. Biederman spin_lock(&sysctl_lock); 10090e47c99dSEric W. Biederman subdir = find_subdir(dir, name, namelen); 10107ec66d06SEric W. Biederman if (!IS_ERR(subdir)) 10117ec66d06SEric W. Biederman goto found; 10127ec66d06SEric W. Biederman if (PTR_ERR(subdir) != -ENOENT) 10137ec66d06SEric W. Biederman goto failed; 10147ec66d06SEric W. Biederman 10157ec66d06SEric W. Biederman spin_unlock(&sysctl_lock); 10167ec66d06SEric W. Biederman new = new_dir(set, name, namelen); 10177ec66d06SEric W. Biederman spin_lock(&sysctl_lock); 10187ec66d06SEric W. Biederman subdir = ERR_PTR(-ENOMEM); 10197ec66d06SEric W. Biederman if (!new) 10207ec66d06SEric W. Biederman goto failed; 10217ec66d06SEric W. Biederman 102260f126d9SEric W. Biederman /* Was the subdir added while we dropped the lock? */ 10230e47c99dSEric W. Biederman subdir = find_subdir(dir, name, namelen); 10247ec66d06SEric W. Biederman if (!IS_ERR(subdir)) 10257ec66d06SEric W. Biederman goto found; 10267ec66d06SEric W. Biederman if (PTR_ERR(subdir) != -ENOENT) 10277ec66d06SEric W. Biederman goto failed; 10287ec66d06SEric W. Biederman 102960f126d9SEric W. Biederman /* Nope. Use the our freshly made directory entry. */ 10300eb97f38SEric W. Biederman err = insert_header(dir, &new->header); 10310eb97f38SEric W. Biederman subdir = ERR_PTR(err); 10320eb97f38SEric W. Biederman if (err) 10330e47c99dSEric W. Biederman goto failed; 10347ec66d06SEric W. Biederman subdir = new; 10357ec66d06SEric W. Biederman found: 10367ec66d06SEric W. Biederman subdir->header.nreg++; 10377ec66d06SEric W. Biederman failed: 1038a1c83681SViresh Kumar if (IS_ERR(subdir)) { 103987ebdc00SAndrew Morton pr_err("sysctl could not get directory: "); 10406980128fSEric W. Biederman sysctl_print_dir(dir); 1041153ee1c4SGeert Uytterhoeven pr_cont("%*.*s %ld\n", namelen, namelen, name, 1042153ee1c4SGeert Uytterhoeven PTR_ERR(subdir)); 10431f87f0b5SEric W. Biederman } 10447ec66d06SEric W. Biederman drop_sysctl_table(&dir->header); 10457ec66d06SEric W. Biederman if (new) 10467ec66d06SEric W. Biederman drop_sysctl_table(&new->header); 10477ec66d06SEric W. Biederman spin_unlock(&sysctl_lock); 10487ec66d06SEric W. Biederman return subdir; 10491f87f0b5SEric W. Biederman } 10501f87f0b5SEric W. Biederman 10510e47c99dSEric W. Biederman static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir) 10520e47c99dSEric W. Biederman { 10530e47c99dSEric W. Biederman struct ctl_dir *parent; 10540e47c99dSEric W. Biederman const char *procname; 10550e47c99dSEric W. Biederman if (!dir->header.parent) 10560e47c99dSEric W. Biederman return &set->dir; 10570e47c99dSEric W. Biederman parent = xlate_dir(set, dir->header.parent); 10580e47c99dSEric W. Biederman if (IS_ERR(parent)) 10590e47c99dSEric W. Biederman return parent; 10600e47c99dSEric W. Biederman procname = dir->header.ctl_table[0].procname; 10610e47c99dSEric W. Biederman return find_subdir(parent, procname, strlen(procname)); 10620e47c99dSEric W. Biederman } 10630e47c99dSEric W. Biederman 10640e47c99dSEric W. Biederman static int sysctl_follow_link(struct ctl_table_header **phead, 106513bcc6a2SEric W. Biederman struct ctl_table **pentry) 10660e47c99dSEric W. Biederman { 10670e47c99dSEric W. Biederman struct ctl_table_header *head; 10680e47c99dSEric W. Biederman struct ctl_table_root *root; 10690e47c99dSEric W. Biederman struct ctl_table_set *set; 10700e47c99dSEric W. Biederman struct ctl_table *entry; 10710e47c99dSEric W. Biederman struct ctl_dir *dir; 10720e47c99dSEric W. Biederman int ret; 10730e47c99dSEric W. Biederman 10740e47c99dSEric W. Biederman spin_lock(&sysctl_lock); 10750e47c99dSEric W. Biederman root = (*pentry)->data; 107613bcc6a2SEric W. Biederman set = lookup_header_set(root); 10770e47c99dSEric W. Biederman dir = xlate_dir(set, (*phead)->parent); 10780e47c99dSEric W. Biederman if (IS_ERR(dir)) 10790e47c99dSEric W. Biederman ret = PTR_ERR(dir); 10800e47c99dSEric W. Biederman else { 10810e47c99dSEric W. Biederman const char *procname = (*pentry)->procname; 10820e47c99dSEric W. Biederman head = NULL; 10830e47c99dSEric W. Biederman entry = find_entry(&head, dir, procname, strlen(procname)); 10840e47c99dSEric W. Biederman ret = -ENOENT; 10850e47c99dSEric W. Biederman if (entry && use_table(head)) { 10860e47c99dSEric W. Biederman unuse_table(*phead); 10870e47c99dSEric W. Biederman *phead = head; 10880e47c99dSEric W. Biederman *pentry = entry; 10890e47c99dSEric W. Biederman ret = 0; 10900e47c99dSEric W. Biederman } 10910e47c99dSEric W. Biederman } 10920e47c99dSEric W. Biederman 10930e47c99dSEric W. Biederman spin_unlock(&sysctl_lock); 10940e47c99dSEric W. Biederman return ret; 10950e47c99dSEric W. Biederman } 10960e47c99dSEric W. Biederman 10977c60c48fSEric W. Biederman static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...) 10987c60c48fSEric W. Biederman { 10997c60c48fSEric W. Biederman struct va_format vaf; 11007c60c48fSEric W. Biederman va_list args; 11017c60c48fSEric W. Biederman 11027c60c48fSEric W. Biederman va_start(args, fmt); 11037c60c48fSEric W. Biederman vaf.fmt = fmt; 11047c60c48fSEric W. Biederman vaf.va = &args; 11057c60c48fSEric W. Biederman 110687ebdc00SAndrew Morton pr_err("sysctl table check failed: %s/%s %pV\n", 11077c60c48fSEric W. Biederman path, table->procname, &vaf); 11087c60c48fSEric W. Biederman 11097c60c48fSEric W. Biederman va_end(args); 11107c60c48fSEric W. Biederman return -EINVAL; 11117c60c48fSEric W. Biederman } 11127c60c48fSEric W. Biederman 11134f2fec00SLuis R. Rodriguez static int sysctl_check_table_array(const char *path, struct ctl_table *table) 11144f2fec00SLuis R. Rodriguez { 11154f2fec00SLuis R. Rodriguez int err = 0; 11164f2fec00SLuis R. Rodriguez 111761d9b56aSLuis R. Rodriguez if ((table->proc_handler == proc_douintvec) || 111861d9b56aSLuis R. Rodriguez (table->proc_handler == proc_douintvec_minmax)) { 11194f2fec00SLuis R. Rodriguez if (table->maxlen != sizeof(unsigned int)) 112064a11f3dSWaiman Long err |= sysctl_err(path, table, "array not allowed"); 11214f2fec00SLuis R. Rodriguez } 11224f2fec00SLuis R. Rodriguez 1123cb944413SEric Dumazet if (table->proc_handler == proc_dou8vec_minmax) { 1124cb944413SEric Dumazet if (table->maxlen != sizeof(u8)) 1125cb944413SEric Dumazet err |= sysctl_err(path, table, "array not allowed"); 1126cb944413SEric Dumazet } 1127cb944413SEric Dumazet 11284f2fec00SLuis R. Rodriguez return err; 11294f2fec00SLuis R. Rodriguez } 11304f2fec00SLuis R. Rodriguez 11317c60c48fSEric W. Biederman static int sysctl_check_table(const char *path, struct ctl_table *table) 11327c60c48fSEric W. Biederman { 11337c60c48fSEric W. Biederman int err = 0; 11347c60c48fSEric W. Biederman for (; table->procname; table++) { 11357c60c48fSEric W. Biederman if (table->child) 113689c5b53bSLuis R. Rodriguez err |= sysctl_err(path, table, "Not a file"); 11377c60c48fSEric W. Biederman 11381f87f0b5SEric W. Biederman if ((table->proc_handler == proc_dostring) || 11391f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec) || 11401680a386SLiping Zhang (table->proc_handler == proc_douintvec) || 114161d9b56aSLuis R. Rodriguez (table->proc_handler == proc_douintvec_minmax) || 11421f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_minmax) || 1143cb944413SEric Dumazet (table->proc_handler == proc_dou8vec_minmax) || 11441f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_jiffies) || 11451f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_userhz_jiffies) || 11461f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_ms_jiffies) || 11471f87f0b5SEric W. Biederman (table->proc_handler == proc_doulongvec_minmax) || 11481f87f0b5SEric W. Biederman (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) { 11491f87f0b5SEric W. Biederman if (!table->data) 115089c5b53bSLuis R. Rodriguez err |= sysctl_err(path, table, "No data"); 11511f87f0b5SEric W. Biederman if (!table->maxlen) 115289c5b53bSLuis R. Rodriguez err |= sysctl_err(path, table, "No maxlen"); 11534f2fec00SLuis R. Rodriguez else 11544f2fec00SLuis R. Rodriguez err |= sysctl_check_table_array(path, table); 11551f87f0b5SEric W. Biederman } 11561f87f0b5SEric W. Biederman if (!table->proc_handler) 115789c5b53bSLuis R. Rodriguez err |= sysctl_err(path, table, "No proc_handler"); 11587c60c48fSEric W. Biederman 11597c60c48fSEric W. Biederman if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode) 116089c5b53bSLuis R. Rodriguez err |= sysctl_err(path, table, "bogus .mode 0%o", 11617c60c48fSEric W. Biederman table->mode); 11621f87f0b5SEric W. Biederman } 11637c60c48fSEric W. Biederman return err; 11641f87f0b5SEric W. Biederman } 11651f87f0b5SEric W. Biederman 11660e47c99dSEric W. Biederman static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table *table, 11670e47c99dSEric W. Biederman struct ctl_table_root *link_root) 11680e47c99dSEric W. Biederman { 11690e47c99dSEric W. Biederman struct ctl_table *link_table, *entry, *link; 11700e47c99dSEric W. Biederman struct ctl_table_header *links; 1171ac13ac6fSEric W. Biederman struct ctl_node *node; 11720e47c99dSEric W. Biederman char *link_name; 11730e47c99dSEric W. Biederman int nr_entries, name_bytes; 11740e47c99dSEric W. Biederman 11750e47c99dSEric W. Biederman name_bytes = 0; 11760e47c99dSEric W. Biederman nr_entries = 0; 11770e47c99dSEric W. Biederman for (entry = table; entry->procname; entry++) { 11780e47c99dSEric W. Biederman nr_entries++; 11790e47c99dSEric W. Biederman name_bytes += strlen(entry->procname) + 1; 11800e47c99dSEric W. Biederman } 11810e47c99dSEric W. Biederman 11820e47c99dSEric W. Biederman links = kzalloc(sizeof(struct ctl_table_header) + 1183ac13ac6fSEric W. Biederman sizeof(struct ctl_node)*nr_entries + 11840e47c99dSEric W. Biederman sizeof(struct ctl_table)*(nr_entries + 1) + 11850e47c99dSEric W. Biederman name_bytes, 11860e47c99dSEric W. Biederman GFP_KERNEL); 11870e47c99dSEric W. Biederman 11880e47c99dSEric W. Biederman if (!links) 11890e47c99dSEric W. Biederman return NULL; 11900e47c99dSEric W. Biederman 1191ac13ac6fSEric W. Biederman node = (struct ctl_node *)(links + 1); 1192ac13ac6fSEric W. Biederman link_table = (struct ctl_table *)(node + nr_entries); 11930e47c99dSEric W. Biederman link_name = (char *)&link_table[nr_entries + 1]; 11940e47c99dSEric W. Biederman 11950e47c99dSEric W. Biederman for (link = link_table, entry = table; entry->procname; link++, entry++) { 11960e47c99dSEric W. Biederman int len = strlen(entry->procname) + 1; 11970e47c99dSEric W. Biederman memcpy(link_name, entry->procname, len); 11980e47c99dSEric W. Biederman link->procname = link_name; 11990e47c99dSEric W. Biederman link->mode = S_IFLNK|S_IRWXUGO; 12000e47c99dSEric W. Biederman link->data = link_root; 12010e47c99dSEric W. Biederman link_name += len; 12020e47c99dSEric W. Biederman } 1203ac13ac6fSEric W. Biederman init_header(links, dir->header.root, dir->header.set, node, link_table); 12040e47c99dSEric W. Biederman links->nreg = nr_entries; 12050e47c99dSEric W. Biederman 12060e47c99dSEric W. Biederman return links; 12070e47c99dSEric W. Biederman } 12080e47c99dSEric W. Biederman 12090e47c99dSEric W. Biederman static bool get_links(struct ctl_dir *dir, 12100e47c99dSEric W. Biederman struct ctl_table *table, struct ctl_table_root *link_root) 12110e47c99dSEric W. Biederman { 12120e47c99dSEric W. Biederman struct ctl_table_header *head; 12130e47c99dSEric W. Biederman struct ctl_table *entry, *link; 12140e47c99dSEric W. Biederman 12150e47c99dSEric W. Biederman /* Are there links available for every entry in table? */ 12160e47c99dSEric W. Biederman for (entry = table; entry->procname; entry++) { 12170e47c99dSEric W. Biederman const char *procname = entry->procname; 12180e47c99dSEric W. Biederman link = find_entry(&head, dir, procname, strlen(procname)); 12190e47c99dSEric W. Biederman if (!link) 12200e47c99dSEric W. Biederman return false; 12210e47c99dSEric W. Biederman if (S_ISDIR(link->mode) && S_ISDIR(entry->mode)) 12220e47c99dSEric W. Biederman continue; 12230e47c99dSEric W. Biederman if (S_ISLNK(link->mode) && (link->data == link_root)) 12240e47c99dSEric W. Biederman continue; 12250e47c99dSEric W. Biederman return false; 12260e47c99dSEric W. Biederman } 12270e47c99dSEric W. Biederman 12280e47c99dSEric W. Biederman /* The checks passed. Increase the registration count on the links */ 12290e47c99dSEric W. Biederman for (entry = table; entry->procname; entry++) { 12300e47c99dSEric W. Biederman const char *procname = entry->procname; 12310e47c99dSEric W. Biederman link = find_entry(&head, dir, procname, strlen(procname)); 12320e47c99dSEric W. Biederman head->nreg++; 12330e47c99dSEric W. Biederman } 12340e47c99dSEric W. Biederman return true; 12350e47c99dSEric W. Biederman } 12360e47c99dSEric W. Biederman 12370e47c99dSEric W. Biederman static int insert_links(struct ctl_table_header *head) 12380e47c99dSEric W. Biederman { 12390e47c99dSEric W. Biederman struct ctl_table_set *root_set = &sysctl_table_root.default_set; 12400e47c99dSEric W. Biederman struct ctl_dir *core_parent = NULL; 12410e47c99dSEric W. Biederman struct ctl_table_header *links; 12420e47c99dSEric W. Biederman int err; 12430e47c99dSEric W. Biederman 12440e47c99dSEric W. Biederman if (head->set == root_set) 12450e47c99dSEric W. Biederman return 0; 12460e47c99dSEric W. Biederman 12470e47c99dSEric W. Biederman core_parent = xlate_dir(root_set, head->parent); 12480e47c99dSEric W. Biederman if (IS_ERR(core_parent)) 12490e47c99dSEric W. Biederman return 0; 12500e47c99dSEric W. Biederman 12510e47c99dSEric W. Biederman if (get_links(core_parent, head->ctl_table, head->root)) 12520e47c99dSEric W. Biederman return 0; 12530e47c99dSEric W. Biederman 12540e47c99dSEric W. Biederman core_parent->header.nreg++; 12550e47c99dSEric W. Biederman spin_unlock(&sysctl_lock); 12560e47c99dSEric W. Biederman 12570e47c99dSEric W. Biederman links = new_links(core_parent, head->ctl_table, head->root); 12580e47c99dSEric W. Biederman 12590e47c99dSEric W. Biederman spin_lock(&sysctl_lock); 12600e47c99dSEric W. Biederman err = -ENOMEM; 12610e47c99dSEric W. Biederman if (!links) 12620e47c99dSEric W. Biederman goto out; 12630e47c99dSEric W. Biederman 12640e47c99dSEric W. Biederman err = 0; 12650e47c99dSEric W. Biederman if (get_links(core_parent, head->ctl_table, head->root)) { 12660e47c99dSEric W. Biederman kfree(links); 12670e47c99dSEric W. Biederman goto out; 12680e47c99dSEric W. Biederman } 12690e47c99dSEric W. Biederman 12700e47c99dSEric W. Biederman err = insert_header(core_parent, links); 12710e47c99dSEric W. Biederman if (err) 12720e47c99dSEric W. Biederman kfree(links); 12730e47c99dSEric W. Biederman out: 12740e47c99dSEric W. Biederman drop_sysctl_table(&core_parent->header); 12750e47c99dSEric W. Biederman return err; 12760e47c99dSEric W. Biederman } 12770e47c99dSEric W. Biederman 12781f87f0b5SEric W. Biederman /** 1279f728019bSEric W. Biederman * __register_sysctl_table - register a leaf sysctl table 128060a47a2eSEric W. Biederman * @set: Sysctl tree to register on 12811f87f0b5SEric W. Biederman * @path: The path to the directory the sysctl table is in. 12821f87f0b5SEric W. Biederman * @table: the top-level table structure 12831f87f0b5SEric W. Biederman * 12841f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 12851f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 12861f87f0b5SEric W. Biederman * 12871f87f0b5SEric W. Biederman * The members of the &struct ctl_table structure are used as follows: 12881f87f0b5SEric W. Biederman * 12891f87f0b5SEric W. Biederman * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not 12901f87f0b5SEric W. Biederman * enter a sysctl file 12911f87f0b5SEric W. Biederman * 12921f87f0b5SEric W. Biederman * data - a pointer to data for use by proc_handler 12931f87f0b5SEric W. Biederman * 12941f87f0b5SEric W. Biederman * maxlen - the maximum size in bytes of the data 12951f87f0b5SEric W. Biederman * 1296f728019bSEric W. Biederman * mode - the file permissions for the /proc/sys file 12971f87f0b5SEric W. Biederman * 1298f728019bSEric W. Biederman * child - must be %NULL. 12991f87f0b5SEric W. Biederman * 13001f87f0b5SEric W. Biederman * proc_handler - the text handler routine (described below) 13011f87f0b5SEric W. Biederman * 13021f87f0b5SEric W. Biederman * extra1, extra2 - extra pointers usable by the proc handler routines 13031f87f0b5SEric W. Biederman * 13041f87f0b5SEric W. Biederman * Leaf nodes in the sysctl tree will be represented by a single file 13051f87f0b5SEric W. Biederman * under /proc; non-leaf nodes will be represented by directories. 13061f87f0b5SEric W. Biederman * 1307f728019bSEric W. Biederman * There must be a proc_handler routine for any terminal nodes. 1308f728019bSEric W. Biederman * Several default handlers are available to cover common cases - 13091f87f0b5SEric W. Biederman * 13101f87f0b5SEric W. Biederman * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), 13111f87f0b5SEric W. Biederman * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 13121f87f0b5SEric W. Biederman * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() 13131f87f0b5SEric W. Biederman * 13141f87f0b5SEric W. Biederman * It is the handler's job to read the input buffer from user memory 13151f87f0b5SEric W. Biederman * and process it. The handler should return 0 on success. 13161f87f0b5SEric W. Biederman * 13171f87f0b5SEric W. Biederman * This routine returns %NULL on a failure to register, and a pointer 13181f87f0b5SEric W. Biederman * to the table header on success. 13191f87f0b5SEric W. Biederman */ 13206e9d5164SEric W. Biederman struct ctl_table_header *__register_sysctl_table( 132160a47a2eSEric W. Biederman struct ctl_table_set *set, 13226e9d5164SEric W. Biederman const char *path, struct ctl_table *table) 13231f87f0b5SEric W. Biederman { 132460a47a2eSEric W. Biederman struct ctl_table_root *root = set->dir.header.root; 13251f87f0b5SEric W. Biederman struct ctl_table_header *header; 13266e9d5164SEric W. Biederman const char *name, *nextname; 13277ec66d06SEric W. Biederman struct ctl_dir *dir; 1328ac13ac6fSEric W. Biederman struct ctl_table *entry; 1329ac13ac6fSEric W. Biederman struct ctl_node *node; 1330ac13ac6fSEric W. Biederman int nr_entries = 0; 13311f87f0b5SEric W. Biederman 1332ac13ac6fSEric W. Biederman for (entry = table; entry->procname; entry++) 1333ac13ac6fSEric W. Biederman nr_entries++; 1334ac13ac6fSEric W. Biederman 1335ac13ac6fSEric W. Biederman header = kzalloc(sizeof(struct ctl_table_header) + 1336ac13ac6fSEric W. Biederman sizeof(struct ctl_node)*nr_entries, GFP_KERNEL); 13371f87f0b5SEric W. Biederman if (!header) 13381f87f0b5SEric W. Biederman return NULL; 13391f87f0b5SEric W. Biederman 1340ac13ac6fSEric W. Biederman node = (struct ctl_node *)(header + 1); 1341ac13ac6fSEric W. Biederman init_header(header, root, set, node, table); 13427c60c48fSEric W. Biederman if (sysctl_check_table(path, table)) 13437c60c48fSEric W. Biederman goto fail; 13448d6ecfccSEric W. Biederman 13451f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 13460e47c99dSEric W. Biederman dir = &set->dir; 134760f126d9SEric W. Biederman /* Reference moved down the diretory tree get_subdir */ 13487ec66d06SEric W. Biederman dir->header.nreg++; 13497ec66d06SEric W. Biederman spin_unlock(&sysctl_lock); 13507ec66d06SEric W. Biederman 13517ec66d06SEric W. Biederman /* Find the directory for the ctl_table */ 13527ec66d06SEric W. Biederman for (name = path; name; name = nextname) { 13537ec66d06SEric W. Biederman int namelen; 13547ec66d06SEric W. Biederman nextname = strchr(name, '/'); 13557ec66d06SEric W. Biederman if (nextname) { 13567ec66d06SEric W. Biederman namelen = nextname - name; 13577ec66d06SEric W. Biederman nextname++; 13587ec66d06SEric W. Biederman } else { 13597ec66d06SEric W. Biederman namelen = strlen(name); 13607ec66d06SEric W. Biederman } 13617ec66d06SEric W. Biederman if (namelen == 0) 13621f87f0b5SEric W. Biederman continue; 13637ec66d06SEric W. Biederman 13640e47c99dSEric W. Biederman dir = get_subdir(dir, name, namelen); 13657ec66d06SEric W. Biederman if (IS_ERR(dir)) 13667ec66d06SEric W. Biederman goto fail; 13671f87f0b5SEric W. Biederman } 13680e47c99dSEric W. Biederman 13697ec66d06SEric W. Biederman spin_lock(&sysctl_lock); 13700e47c99dSEric W. Biederman if (insert_header(dir, header)) 13710e47c99dSEric W. Biederman goto fail_put_dir_locked; 13720e47c99dSEric W. Biederman 13737ec66d06SEric W. Biederman drop_sysctl_table(&dir->header); 13741f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 13751f87f0b5SEric W. Biederman 13761f87f0b5SEric W. Biederman return header; 13770e47c99dSEric W. Biederman 13787ec66d06SEric W. Biederman fail_put_dir_locked: 13797ec66d06SEric W. Biederman drop_sysctl_table(&dir->header); 13807c60c48fSEric W. Biederman spin_unlock(&sysctl_lock); 13817c60c48fSEric W. Biederman fail: 13827c60c48fSEric W. Biederman kfree(header); 13837c60c48fSEric W. Biederman dump_stack(); 13847c60c48fSEric W. Biederman return NULL; 13851f87f0b5SEric W. Biederman } 13861f87f0b5SEric W. Biederman 1387fea478d4SEric W. Biederman /** 1388fea478d4SEric W. Biederman * register_sysctl - register a sysctl table 1389fea478d4SEric W. Biederman * @path: The path to the directory the sysctl table is in. 1390fea478d4SEric W. Biederman * @table: the table structure 1391fea478d4SEric W. Biederman * 1392fea478d4SEric W. Biederman * Register a sysctl table. @table should be a filled in ctl_table 1393fea478d4SEric W. Biederman * array. A completely 0 filled entry terminates the table. 1394fea478d4SEric W. Biederman * 1395fea478d4SEric W. Biederman * See __register_sysctl_table for more details. 1396fea478d4SEric W. Biederman */ 1397fea478d4SEric W. Biederman struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) 1398fea478d4SEric W. Biederman { 1399fea478d4SEric W. Biederman return __register_sysctl_table(&sysctl_table_root.default_set, 1400fea478d4SEric W. Biederman path, table); 1401fea478d4SEric W. Biederman } 1402fea478d4SEric W. Biederman EXPORT_SYMBOL(register_sysctl); 1403fea478d4SEric W. Biederman 14043ddd9a80SXiaoming Ni /** 14053ddd9a80SXiaoming Ni * __register_sysctl_init() - register sysctl table to path 14063ddd9a80SXiaoming Ni * @path: path name for sysctl base 14073ddd9a80SXiaoming Ni * @table: This is the sysctl table that needs to be registered to the path 14083ddd9a80SXiaoming Ni * @table_name: The name of sysctl table, only used for log printing when 14093ddd9a80SXiaoming Ni * registration fails 14103ddd9a80SXiaoming Ni * 14113ddd9a80SXiaoming Ni * The sysctl interface is used by userspace to query or modify at runtime 14123ddd9a80SXiaoming Ni * a predefined value set on a variable. These variables however have default 14133ddd9a80SXiaoming Ni * values pre-set. Code which depends on these variables will always work even 14143ddd9a80SXiaoming Ni * if register_sysctl() fails. If register_sysctl() fails you'd just loose the 14153ddd9a80SXiaoming Ni * ability to query or modify the sysctls dynamically at run time. Chances of 14163ddd9a80SXiaoming Ni * register_sysctl() failing on init are extremely low, and so for both reasons 14173ddd9a80SXiaoming Ni * this function does not return any error as it is used by initialization code. 14183ddd9a80SXiaoming Ni * 14193ddd9a80SXiaoming Ni * Context: Can only be called after your respective sysctl base path has been 14203ddd9a80SXiaoming Ni * registered. So for instance, most base directories are registered early on 14213ddd9a80SXiaoming Ni * init before init levels are processed through proc_sys_init() and 1422*d8c0418aSLuis Chamberlain * sysctl_init_bases(). 14233ddd9a80SXiaoming Ni */ 14243ddd9a80SXiaoming Ni void __init __register_sysctl_init(const char *path, struct ctl_table *table, 14253ddd9a80SXiaoming Ni const char *table_name) 14263ddd9a80SXiaoming Ni { 14273ddd9a80SXiaoming Ni struct ctl_table_header *hdr = register_sysctl(path, table); 14283ddd9a80SXiaoming Ni 14293ddd9a80SXiaoming Ni if (unlikely(!hdr)) { 14303ddd9a80SXiaoming Ni pr_err("failed when register_sysctl %s to %s\n", table_name, path); 14313ddd9a80SXiaoming Ni return; 14323ddd9a80SXiaoming Ni } 14333ddd9a80SXiaoming Ni kmemleak_not_leak(hdr); 14343ddd9a80SXiaoming Ni } 14353ddd9a80SXiaoming Ni 14366e9d5164SEric W. Biederman static char *append_path(const char *path, char *pos, const char *name) 14376e9d5164SEric W. Biederman { 14386e9d5164SEric W. Biederman int namelen; 14396e9d5164SEric W. Biederman namelen = strlen(name); 14406e9d5164SEric W. Biederman if (((pos - path) + namelen + 2) >= PATH_MAX) 14416e9d5164SEric W. Biederman return NULL; 14426e9d5164SEric W. Biederman memcpy(pos, name, namelen); 14436e9d5164SEric W. Biederman pos[namelen] = '/'; 14446e9d5164SEric W. Biederman pos[namelen + 1] = '\0'; 14456e9d5164SEric W. Biederman pos += namelen + 1; 14466e9d5164SEric W. Biederman return pos; 14476e9d5164SEric W. Biederman } 14486e9d5164SEric W. Biederman 1449f728019bSEric W. Biederman static int count_subheaders(struct ctl_table *table) 1450f728019bSEric W. Biederman { 1451f728019bSEric W. Biederman int has_files = 0; 1452f728019bSEric W. Biederman int nr_subheaders = 0; 1453f728019bSEric W. Biederman struct ctl_table *entry; 1454f728019bSEric W. Biederman 1455f728019bSEric W. Biederman /* special case: no directory and empty directory */ 1456f728019bSEric W. Biederman if (!table || !table->procname) 1457f728019bSEric W. Biederman return 1; 1458f728019bSEric W. Biederman 1459f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1460f728019bSEric W. Biederman if (entry->child) 1461f728019bSEric W. Biederman nr_subheaders += count_subheaders(entry->child); 1462f728019bSEric W. Biederman else 1463f728019bSEric W. Biederman has_files = 1; 1464f728019bSEric W. Biederman } 1465f728019bSEric W. Biederman return nr_subheaders + has_files; 1466f728019bSEric W. Biederman } 1467f728019bSEric W. Biederman 1468f728019bSEric W. Biederman static int register_leaf_sysctl_tables(const char *path, char *pos, 146960a47a2eSEric W. Biederman struct ctl_table_header ***subheader, struct ctl_table_set *set, 1470f728019bSEric W. Biederman struct ctl_table *table) 1471f728019bSEric W. Biederman { 1472f728019bSEric W. Biederman struct ctl_table *ctl_table_arg = NULL; 1473f728019bSEric W. Biederman struct ctl_table *entry, *files; 1474f728019bSEric W. Biederman int nr_files = 0; 1475f728019bSEric W. Biederman int nr_dirs = 0; 1476f728019bSEric W. Biederman int err = -ENOMEM; 1477f728019bSEric W. Biederman 1478f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1479f728019bSEric W. Biederman if (entry->child) 1480f728019bSEric W. Biederman nr_dirs++; 1481f728019bSEric W. Biederman else 1482f728019bSEric W. Biederman nr_files++; 1483f728019bSEric W. Biederman } 1484f728019bSEric W. Biederman 1485f728019bSEric W. Biederman files = table; 1486f728019bSEric W. Biederman /* If there are mixed files and directories we need a new table */ 1487f728019bSEric W. Biederman if (nr_dirs && nr_files) { 1488f728019bSEric W. Biederman struct ctl_table *new; 14896396bb22SKees Cook files = kcalloc(nr_files + 1, sizeof(struct ctl_table), 1490f728019bSEric W. Biederman GFP_KERNEL); 1491f728019bSEric W. Biederman if (!files) 1492f728019bSEric W. Biederman goto out; 1493f728019bSEric W. Biederman 1494f728019bSEric W. Biederman ctl_table_arg = files; 1495f728019bSEric W. Biederman for (new = files, entry = table; entry->procname; entry++) { 1496f728019bSEric W. Biederman if (entry->child) 1497f728019bSEric W. Biederman continue; 1498f728019bSEric W. Biederman *new = *entry; 1499f728019bSEric W. Biederman new++; 1500f728019bSEric W. Biederman } 1501f728019bSEric W. Biederman } 1502f728019bSEric W. Biederman 1503f728019bSEric W. Biederman /* Register everything except a directory full of subdirectories */ 1504f728019bSEric W. Biederman if (nr_files || !nr_dirs) { 1505f728019bSEric W. Biederman struct ctl_table_header *header; 150660a47a2eSEric W. Biederman header = __register_sysctl_table(set, path, files); 1507f728019bSEric W. Biederman if (!header) { 1508f728019bSEric W. Biederman kfree(ctl_table_arg); 1509f728019bSEric W. Biederman goto out; 1510f728019bSEric W. Biederman } 1511f728019bSEric W. Biederman 1512f728019bSEric W. Biederman /* Remember if we need to free the file table */ 1513f728019bSEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1514f728019bSEric W. Biederman **subheader = header; 1515f728019bSEric W. Biederman (*subheader)++; 1516f728019bSEric W. Biederman } 1517f728019bSEric W. Biederman 1518f728019bSEric W. Biederman /* Recurse into the subdirectories. */ 1519f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1520f728019bSEric W. Biederman char *child_pos; 1521f728019bSEric W. Biederman 1522f728019bSEric W. Biederman if (!entry->child) 1523f728019bSEric W. Biederman continue; 1524f728019bSEric W. Biederman 1525f728019bSEric W. Biederman err = -ENAMETOOLONG; 1526f728019bSEric W. Biederman child_pos = append_path(path, pos, entry->procname); 1527f728019bSEric W. Biederman if (!child_pos) 1528f728019bSEric W. Biederman goto out; 1529f728019bSEric W. Biederman 1530f728019bSEric W. Biederman err = register_leaf_sysctl_tables(path, child_pos, subheader, 153160a47a2eSEric W. Biederman set, entry->child); 1532f728019bSEric W. Biederman pos[0] = '\0'; 1533f728019bSEric W. Biederman if (err) 1534f728019bSEric W. Biederman goto out; 1535f728019bSEric W. Biederman } 1536f728019bSEric W. Biederman err = 0; 1537f728019bSEric W. Biederman out: 1538f728019bSEric W. Biederman /* On failure our caller will unregister all registered subheaders */ 1539f728019bSEric W. Biederman return err; 1540f728019bSEric W. Biederman } 1541f728019bSEric W. Biederman 15426e9d5164SEric W. Biederman /** 15436e9d5164SEric W. Biederman * __register_sysctl_paths - register a sysctl table hierarchy 154460a47a2eSEric W. Biederman * @set: Sysctl tree to register on 15456e9d5164SEric W. Biederman * @path: The path to the directory the sysctl table is in. 15466e9d5164SEric W. Biederman * @table: the top-level table structure 15476e9d5164SEric W. Biederman * 15486e9d5164SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 15496e9d5164SEric W. Biederman * array. A completely 0 filled entry terminates the table. 15506e9d5164SEric W. Biederman * 15516e9d5164SEric W. Biederman * See __register_sysctl_table for more details. 15526e9d5164SEric W. Biederman */ 15536e9d5164SEric W. Biederman struct ctl_table_header *__register_sysctl_paths( 155460a47a2eSEric W. Biederman struct ctl_table_set *set, 15556e9d5164SEric W. Biederman const struct ctl_path *path, struct ctl_table *table) 15566e9d5164SEric W. Biederman { 1557ec6a5266SEric W. Biederman struct ctl_table *ctl_table_arg = table; 1558f728019bSEric W. Biederman int nr_subheaders = count_subheaders(table); 1559f728019bSEric W. Biederman struct ctl_table_header *header = NULL, **subheaders, **subheader; 15606e9d5164SEric W. Biederman const struct ctl_path *component; 15616e9d5164SEric W. Biederman char *new_path, *pos; 15626e9d5164SEric W. Biederman 15636e9d5164SEric W. Biederman pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); 15646e9d5164SEric W. Biederman if (!new_path) 15656e9d5164SEric W. Biederman return NULL; 15666e9d5164SEric W. Biederman 15676e9d5164SEric W. Biederman pos[0] = '\0'; 15686e9d5164SEric W. Biederman for (component = path; component->procname; component++) { 15696e9d5164SEric W. Biederman pos = append_path(new_path, pos, component->procname); 15706e9d5164SEric W. Biederman if (!pos) 15716e9d5164SEric W. Biederman goto out; 15726e9d5164SEric W. Biederman } 1573ec6a5266SEric W. Biederman while (table->procname && table->child && !table[1].procname) { 1574ec6a5266SEric W. Biederman pos = append_path(new_path, pos, table->procname); 1575ec6a5266SEric W. Biederman if (!pos) 1576ec6a5266SEric W. Biederman goto out; 1577ec6a5266SEric W. Biederman table = table->child; 1578ec6a5266SEric W. Biederman } 1579f728019bSEric W. Biederman if (nr_subheaders == 1) { 158060a47a2eSEric W. Biederman header = __register_sysctl_table(set, new_path, table); 1581ec6a5266SEric W. Biederman if (header) 1582ec6a5266SEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1583f728019bSEric W. Biederman } else { 1584f728019bSEric W. Biederman header = kzalloc(sizeof(*header) + 1585f728019bSEric W. Biederman sizeof(*subheaders)*nr_subheaders, GFP_KERNEL); 1586f728019bSEric W. Biederman if (!header) 1587f728019bSEric W. Biederman goto out; 1588f728019bSEric W. Biederman 1589f728019bSEric W. Biederman subheaders = (struct ctl_table_header **) (header + 1); 1590f728019bSEric W. Biederman subheader = subheaders; 1591f728019bSEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1592f728019bSEric W. Biederman 1593f728019bSEric W. Biederman if (register_leaf_sysctl_tables(new_path, pos, &subheader, 159460a47a2eSEric W. Biederman set, table)) 1595f728019bSEric W. Biederman goto err_register_leaves; 1596f728019bSEric W. Biederman } 1597f728019bSEric W. Biederman 15986e9d5164SEric W. Biederman out: 15996e9d5164SEric W. Biederman kfree(new_path); 16006e9d5164SEric W. Biederman return header; 1601f728019bSEric W. Biederman 1602f728019bSEric W. Biederman err_register_leaves: 1603f728019bSEric W. Biederman while (subheader > subheaders) { 1604f728019bSEric W. Biederman struct ctl_table_header *subh = *(--subheader); 1605f728019bSEric W. Biederman struct ctl_table *table = subh->ctl_table_arg; 1606f728019bSEric W. Biederman unregister_sysctl_table(subh); 1607f728019bSEric W. Biederman kfree(table); 1608f728019bSEric W. Biederman } 1609f728019bSEric W. Biederman kfree(header); 1610f728019bSEric W. Biederman header = NULL; 1611f728019bSEric W. Biederman goto out; 16126e9d5164SEric W. Biederman } 16136e9d5164SEric W. Biederman 16141f87f0b5SEric W. Biederman /** 16155b31a7dfSzhouchuangao * register_sysctl_paths - register a sysctl table hierarchy 16161f87f0b5SEric W. Biederman * @path: The path to the directory the sysctl table is in. 16171f87f0b5SEric W. Biederman * @table: the top-level table structure 16181f87f0b5SEric W. Biederman * 16191f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 16201f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 16211f87f0b5SEric W. Biederman * 16221f87f0b5SEric W. Biederman * See __register_sysctl_paths for more details. 16231f87f0b5SEric W. Biederman */ 16241f87f0b5SEric W. Biederman struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, 16251f87f0b5SEric W. Biederman struct ctl_table *table) 16261f87f0b5SEric W. Biederman { 162760a47a2eSEric W. Biederman return __register_sysctl_paths(&sysctl_table_root.default_set, 16281f87f0b5SEric W. Biederman path, table); 16291f87f0b5SEric W. Biederman } 16301f87f0b5SEric W. Biederman EXPORT_SYMBOL(register_sysctl_paths); 16311f87f0b5SEric W. Biederman 16321f87f0b5SEric W. Biederman /** 16331f87f0b5SEric W. Biederman * register_sysctl_table - register a sysctl table hierarchy 16341f87f0b5SEric W. Biederman * @table: the top-level table structure 16351f87f0b5SEric W. Biederman * 16361f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 16371f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 16381f87f0b5SEric W. Biederman * 16391f87f0b5SEric W. Biederman * See register_sysctl_paths for more details. 16401f87f0b5SEric W. Biederman */ 16411f87f0b5SEric W. Biederman struct ctl_table_header *register_sysctl_table(struct ctl_table *table) 16421f87f0b5SEric W. Biederman { 16431f87f0b5SEric W. Biederman static const struct ctl_path null_path[] = { {} }; 16441f87f0b5SEric W. Biederman 16451f87f0b5SEric W. Biederman return register_sysctl_paths(null_path, table); 16461f87f0b5SEric W. Biederman } 16471f87f0b5SEric W. Biederman EXPORT_SYMBOL(register_sysctl_table); 16481f87f0b5SEric W. Biederman 164951cb8dfcSLuis Chamberlain int __register_sysctl_base(struct ctl_table *base_table) 165051cb8dfcSLuis Chamberlain { 165151cb8dfcSLuis Chamberlain struct ctl_table_header *hdr; 165251cb8dfcSLuis Chamberlain 165351cb8dfcSLuis Chamberlain hdr = register_sysctl_table(base_table); 165451cb8dfcSLuis Chamberlain kmemleak_not_leak(hdr); 165551cb8dfcSLuis Chamberlain return 0; 165651cb8dfcSLuis Chamberlain } 165751cb8dfcSLuis Chamberlain 16580e47c99dSEric W. Biederman static void put_links(struct ctl_table_header *header) 16590e47c99dSEric W. Biederman { 16600e47c99dSEric W. Biederman struct ctl_table_set *root_set = &sysctl_table_root.default_set; 16610e47c99dSEric W. Biederman struct ctl_table_root *root = header->root; 16620e47c99dSEric W. Biederman struct ctl_dir *parent = header->parent; 16630e47c99dSEric W. Biederman struct ctl_dir *core_parent; 16640e47c99dSEric W. Biederman struct ctl_table *entry; 16650e47c99dSEric W. Biederman 16660e47c99dSEric W. Biederman if (header->set == root_set) 16670e47c99dSEric W. Biederman return; 16680e47c99dSEric W. Biederman 16690e47c99dSEric W. Biederman core_parent = xlate_dir(root_set, parent); 16700e47c99dSEric W. Biederman if (IS_ERR(core_parent)) 16710e47c99dSEric W. Biederman return; 16720e47c99dSEric W. Biederman 16730e47c99dSEric W. Biederman for (entry = header->ctl_table; entry->procname; entry++) { 16740e47c99dSEric W. Biederman struct ctl_table_header *link_head; 16750e47c99dSEric W. Biederman struct ctl_table *link; 16760e47c99dSEric W. Biederman const char *name = entry->procname; 16770e47c99dSEric W. Biederman 16780e47c99dSEric W. Biederman link = find_entry(&link_head, core_parent, name, strlen(name)); 16790e47c99dSEric W. Biederman if (link && 16800e47c99dSEric W. Biederman ((S_ISDIR(link->mode) && S_ISDIR(entry->mode)) || 16810e47c99dSEric W. Biederman (S_ISLNK(link->mode) && (link->data == root)))) { 16820e47c99dSEric W. Biederman drop_sysctl_table(link_head); 16830e47c99dSEric W. Biederman } 16840e47c99dSEric W. Biederman else { 168587ebdc00SAndrew Morton pr_err("sysctl link missing during unregister: "); 16860e47c99dSEric W. Biederman sysctl_print_dir(parent); 1687153ee1c4SGeert Uytterhoeven pr_cont("%s\n", name); 16880e47c99dSEric W. Biederman } 16890e47c99dSEric W. Biederman } 16900e47c99dSEric W. Biederman } 16910e47c99dSEric W. Biederman 1692938aaa4fSEric W. Biederman static void drop_sysctl_table(struct ctl_table_header *header) 1693938aaa4fSEric W. Biederman { 16947ec66d06SEric W. Biederman struct ctl_dir *parent = header->parent; 16957ec66d06SEric W. Biederman 1696938aaa4fSEric W. Biederman if (--header->nreg) 1697938aaa4fSEric W. Biederman return; 1698938aaa4fSEric W. Biederman 169989189557SYueHaibing if (parent) { 17000e47c99dSEric W. Biederman put_links(header); 1701938aaa4fSEric W. Biederman start_unregistering(header); 170289189557SYueHaibing } 170389189557SYueHaibing 1704938aaa4fSEric W. Biederman if (!--header->count) 1705938aaa4fSEric W. Biederman kfree_rcu(header, rcu); 17067ec66d06SEric W. Biederman 17077ec66d06SEric W. Biederman if (parent) 17087ec66d06SEric W. Biederman drop_sysctl_table(&parent->header); 1709938aaa4fSEric W. Biederman } 1710938aaa4fSEric W. Biederman 17111f87f0b5SEric W. Biederman /** 17121f87f0b5SEric W. Biederman * unregister_sysctl_table - unregister a sysctl table hierarchy 17131f87f0b5SEric W. Biederman * @header: the header returned from register_sysctl_table 17141f87f0b5SEric W. Biederman * 17151f87f0b5SEric W. Biederman * Unregisters the sysctl table and all children. proc entries may not 17161f87f0b5SEric W. Biederman * actually be removed until they are no longer used by anyone. 17171f87f0b5SEric W. Biederman */ 17181f87f0b5SEric W. Biederman void unregister_sysctl_table(struct ctl_table_header * header) 17191f87f0b5SEric W. Biederman { 1720f728019bSEric W. Biederman int nr_subheaders; 17211f87f0b5SEric W. Biederman might_sleep(); 17221f87f0b5SEric W. Biederman 17231f87f0b5SEric W. Biederman if (header == NULL) 17241f87f0b5SEric W. Biederman return; 17251f87f0b5SEric W. Biederman 1726f728019bSEric W. Biederman nr_subheaders = count_subheaders(header->ctl_table_arg); 1727f728019bSEric W. Biederman if (unlikely(nr_subheaders > 1)) { 1728f728019bSEric W. Biederman struct ctl_table_header **subheaders; 1729f728019bSEric W. Biederman int i; 1730f728019bSEric W. Biederman 1731f728019bSEric W. Biederman subheaders = (struct ctl_table_header **)(header + 1); 1732f728019bSEric W. Biederman for (i = nr_subheaders -1; i >= 0; i--) { 1733f728019bSEric W. Biederman struct ctl_table_header *subh = subheaders[i]; 1734f728019bSEric W. Biederman struct ctl_table *table = subh->ctl_table_arg; 1735f728019bSEric W. Biederman unregister_sysctl_table(subh); 1736f728019bSEric W. Biederman kfree(table); 1737f728019bSEric W. Biederman } 1738f728019bSEric W. Biederman kfree(header); 1739f728019bSEric W. Biederman return; 1740f728019bSEric W. Biederman } 1741f728019bSEric W. Biederman 17421f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1743938aaa4fSEric W. Biederman drop_sysctl_table(header); 17441f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 17451f87f0b5SEric W. Biederman } 17461f87f0b5SEric W. Biederman EXPORT_SYMBOL(unregister_sysctl_table); 17471f87f0b5SEric W. Biederman 17480e47c99dSEric W. Biederman void setup_sysctl_set(struct ctl_table_set *set, 17499eb47c26SEric W. Biederman struct ctl_table_root *root, 17501f87f0b5SEric W. Biederman int (*is_seen)(struct ctl_table_set *)) 17511f87f0b5SEric W. Biederman { 17521347440dSDan Carpenter memset(set, 0, sizeof(*set)); 17530e47c99dSEric W. Biederman set->is_seen = is_seen; 1754ac13ac6fSEric W. Biederman init_header(&set->dir.header, root, set, NULL, root_table); 17551f87f0b5SEric W. Biederman } 17561f87f0b5SEric W. Biederman 175797324cd8SEric W. Biederman void retire_sysctl_set(struct ctl_table_set *set) 175897324cd8SEric W. Biederman { 1759ac13ac6fSEric W. Biederman WARN_ON(!RB_EMPTY_ROOT(&set->dir.root)); 176097324cd8SEric W. Biederman } 17611f87f0b5SEric W. Biederman 17621e0edd3fSAlexey Dobriyan int __init proc_sys_init(void) 176377b14db5SEric W. Biederman { 1764e1675231SAlexey Dobriyan struct proc_dir_entry *proc_sys_root; 1765e1675231SAlexey Dobriyan 176677b14db5SEric W. Biederman proc_sys_root = proc_mkdir("sys", NULL); 17679043476fSAl Viro proc_sys_root->proc_iops = &proc_sys_dir_operations; 1768d56c0d45SAlexey Dobriyan proc_sys_root->proc_dir_ops = &proc_sys_dir_file_operations; 176977b14db5SEric W. Biederman proc_sys_root->nlink = 0; 1770de4e83bdSEric W. Biederman 1771*d8c0418aSLuis Chamberlain return sysctl_init_bases(); 177277b14db5SEric W. Biederman } 17733db978d4SVlastimil Babka 17740a477e1aSVlastimil Babka struct sysctl_alias { 17750a477e1aSVlastimil Babka const char *kernel_param; 17760a477e1aSVlastimil Babka const char *sysctl_param; 17770a477e1aSVlastimil Babka }; 17780a477e1aSVlastimil Babka 17790a477e1aSVlastimil Babka /* 17800a477e1aSVlastimil Babka * Historically some settings had both sysctl and a command line parameter. 17810a477e1aSVlastimil Babka * With the generic sysctl. parameter support, we can handle them at a single 17820a477e1aSVlastimil Babka * place and only keep the historical name for compatibility. This is not meant 17830a477e1aSVlastimil Babka * to add brand new aliases. When adding existing aliases, consider whether 17840a477e1aSVlastimil Babka * the possibly different moment of changing the value (e.g. from early_param 17850a477e1aSVlastimil Babka * to the moment do_sysctl_args() is called) is an issue for the specific 17860a477e1aSVlastimil Babka * parameter. 17870a477e1aSVlastimil Babka */ 17880a477e1aSVlastimil Babka static const struct sysctl_alias sysctl_aliases[] = { 1789f117955aSGuilherme G. Piccoli {"hardlockup_all_cpu_backtrace", "kernel.hardlockup_all_cpu_backtrace" }, 1790b467f3efSVlastimil Babka {"hung_task_panic", "kernel.hung_task_panic" }, 1791f117955aSGuilherme G. Piccoli {"numa_zonelist_order", "vm.numa_zonelist_order" }, 1792f117955aSGuilherme G. Piccoli {"softlockup_all_cpu_backtrace", "kernel.softlockup_all_cpu_backtrace" }, 1793f117955aSGuilherme G. Piccoli {"softlockup_panic", "kernel.softlockup_panic" }, 17940a477e1aSVlastimil Babka { } 17950a477e1aSVlastimil Babka }; 17960a477e1aSVlastimil Babka 17970a477e1aSVlastimil Babka static const char *sysctl_find_alias(char *param) 17980a477e1aSVlastimil Babka { 17990a477e1aSVlastimil Babka const struct sysctl_alias *alias; 18000a477e1aSVlastimil Babka 18010a477e1aSVlastimil Babka for (alias = &sysctl_aliases[0]; alias->kernel_param != NULL; alias++) { 18020a477e1aSVlastimil Babka if (strcmp(alias->kernel_param, param) == 0) 18030a477e1aSVlastimil Babka return alias->sysctl_param; 18040a477e1aSVlastimil Babka } 18050a477e1aSVlastimil Babka 18060a477e1aSVlastimil Babka return NULL; 18070a477e1aSVlastimil Babka } 18080a477e1aSVlastimil Babka 18093db978d4SVlastimil Babka /* Set sysctl value passed on kernel command line. */ 18103db978d4SVlastimil Babka static int process_sysctl_arg(char *param, char *val, 18113db978d4SVlastimil Babka const char *unused, void *arg) 18123db978d4SVlastimil Babka { 18133db978d4SVlastimil Babka char *path; 18143db978d4SVlastimil Babka struct vfsmount **proc_mnt = arg; 18153db978d4SVlastimil Babka struct file_system_type *proc_fs_type; 18163db978d4SVlastimil Babka struct file *file; 18173db978d4SVlastimil Babka int len; 18183db978d4SVlastimil Babka int err; 18193db978d4SVlastimil Babka loff_t pos = 0; 18203db978d4SVlastimil Babka ssize_t wret; 18213db978d4SVlastimil Babka 18220a477e1aSVlastimil Babka if (strncmp(param, "sysctl", sizeof("sysctl") - 1) == 0) { 18233db978d4SVlastimil Babka param += sizeof("sysctl") - 1; 18243db978d4SVlastimil Babka 18253db978d4SVlastimil Babka if (param[0] != '/' && param[0] != '.') 18263db978d4SVlastimil Babka return 0; 18273db978d4SVlastimil Babka 18283db978d4SVlastimil Babka param++; 18290a477e1aSVlastimil Babka } else { 18300a477e1aSVlastimil Babka param = (char *) sysctl_find_alias(param); 18310a477e1aSVlastimil Babka if (!param) 18320a477e1aSVlastimil Babka return 0; 18330a477e1aSVlastimil Babka } 18343db978d4SVlastimil Babka 1835697edcb0SXiaoming Ni if (!val) 1836697edcb0SXiaoming Ni return -EINVAL; 1837697edcb0SXiaoming Ni len = strlen(val); 1838697edcb0SXiaoming Ni if (len == 0) 1839697edcb0SXiaoming Ni return -EINVAL; 1840697edcb0SXiaoming Ni 18413db978d4SVlastimil Babka /* 18423db978d4SVlastimil Babka * To set sysctl options, we use a temporary mount of proc, look up the 18433db978d4SVlastimil Babka * respective sys/ file and write to it. To avoid mounting it when no 18443db978d4SVlastimil Babka * options were given, we mount it only when the first sysctl option is 18453db978d4SVlastimil Babka * found. Why not a persistent mount? There are problems with a 18463db978d4SVlastimil Babka * persistent mount of proc in that it forces userspace not to use any 18473db978d4SVlastimil Babka * proc mount options. 18483db978d4SVlastimil Babka */ 18493db978d4SVlastimil Babka if (!*proc_mnt) { 18503db978d4SVlastimil Babka proc_fs_type = get_fs_type("proc"); 18513db978d4SVlastimil Babka if (!proc_fs_type) { 18523db978d4SVlastimil Babka pr_err("Failed to find procfs to set sysctl from command line\n"); 18533db978d4SVlastimil Babka return 0; 18543db978d4SVlastimil Babka } 18553db978d4SVlastimil Babka *proc_mnt = kern_mount(proc_fs_type); 18563db978d4SVlastimil Babka put_filesystem(proc_fs_type); 18573db978d4SVlastimil Babka if (IS_ERR(*proc_mnt)) { 18583db978d4SVlastimil Babka pr_err("Failed to mount procfs to set sysctl from command line\n"); 18593db978d4SVlastimil Babka return 0; 18603db978d4SVlastimil Babka } 18613db978d4SVlastimil Babka } 18623db978d4SVlastimil Babka 18633db978d4SVlastimil Babka path = kasprintf(GFP_KERNEL, "sys/%s", param); 18643db978d4SVlastimil Babka if (!path) 18653db978d4SVlastimil Babka panic("%s: Failed to allocate path for %s\n", __func__, param); 18663db978d4SVlastimil Babka strreplace(path, '.', '/'); 18673db978d4SVlastimil Babka 1868ffb37ca3SAl Viro file = file_open_root_mnt(*proc_mnt, path, O_WRONLY, 0); 18693db978d4SVlastimil Babka if (IS_ERR(file)) { 18703db978d4SVlastimil Babka err = PTR_ERR(file); 18713db978d4SVlastimil Babka if (err == -ENOENT) 18723db978d4SVlastimil Babka pr_err("Failed to set sysctl parameter '%s=%s': parameter not found\n", 18733db978d4SVlastimil Babka param, val); 18743db978d4SVlastimil Babka else if (err == -EACCES) 18753db978d4SVlastimil Babka pr_err("Failed to set sysctl parameter '%s=%s': permission denied (read-only?)\n", 18763db978d4SVlastimil Babka param, val); 18773db978d4SVlastimil Babka else 18783db978d4SVlastimil Babka pr_err("Error %pe opening proc file to set sysctl parameter '%s=%s'\n", 18793db978d4SVlastimil Babka file, param, val); 18803db978d4SVlastimil Babka goto out; 18813db978d4SVlastimil Babka } 18823db978d4SVlastimil Babka wret = kernel_write(file, val, len, &pos); 18833db978d4SVlastimil Babka if (wret < 0) { 18843db978d4SVlastimil Babka err = wret; 18853db978d4SVlastimil Babka if (err == -EINVAL) 18863db978d4SVlastimil Babka pr_err("Failed to set sysctl parameter '%s=%s': invalid value\n", 18873db978d4SVlastimil Babka param, val); 18883db978d4SVlastimil Babka else 18893db978d4SVlastimil Babka pr_err("Error %pe writing to proc file to set sysctl parameter '%s=%s'\n", 18903db978d4SVlastimil Babka ERR_PTR(err), param, val); 18913db978d4SVlastimil Babka } else if (wret != len) { 18923db978d4SVlastimil Babka pr_err("Wrote only %zd bytes of %d writing to proc file %s to set sysctl parameter '%s=%s\n", 18933db978d4SVlastimil Babka wret, len, path, param, val); 18943db978d4SVlastimil Babka } 18953db978d4SVlastimil Babka 18963db978d4SVlastimil Babka err = filp_close(file, NULL); 18973db978d4SVlastimil Babka if (err) 18983db978d4SVlastimil Babka pr_err("Error %pe closing proc file to set sysctl parameter '%s=%s\n", 18993db978d4SVlastimil Babka ERR_PTR(err), param, val); 19003db978d4SVlastimil Babka out: 19013db978d4SVlastimil Babka kfree(path); 19023db978d4SVlastimil Babka return 0; 19033db978d4SVlastimil Babka } 19043db978d4SVlastimil Babka 19053db978d4SVlastimil Babka void do_sysctl_args(void) 19063db978d4SVlastimil Babka { 19073db978d4SVlastimil Babka char *command_line; 19083db978d4SVlastimil Babka struct vfsmount *proc_mnt = NULL; 19093db978d4SVlastimil Babka 19103db978d4SVlastimil Babka command_line = kstrdup(saved_command_line, GFP_KERNEL); 19113db978d4SVlastimil Babka if (!command_line) 19123db978d4SVlastimil Babka panic("%s: Failed to allocate copy of command line\n", __func__); 19133db978d4SVlastimil Babka 19143db978d4SVlastimil Babka parse_args("Setting sysctl args", command_line, 19153db978d4SVlastimil Babka NULL, 0, -1, -1, &proc_mnt, process_sysctl_arg); 19163db978d4SVlastimil Babka 19173db978d4SVlastimil Babka if (proc_mnt) 19183db978d4SVlastimil Babka kern_unmount(proc_mnt); 19193db978d4SVlastimil Babka 19203db978d4SVlastimil Babka kfree(command_line); 19213db978d4SVlastimil Babka } 1922