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 */ 2978e36f3bSXiaoming Ni const int sysctl_vals[] = { -1, 0, 1, 2, 4, 100, 200, 1000, 3000, INT_MAX }; 30eec4844fSMatteo Croce EXPORT_SYMBOL(sysctl_vals); 31eec4844fSMatteo Croce 32f9bd6733SEric W. Biederman /* Support for permanently empty directories */ 33f9bd6733SEric W. Biederman 34f9bd6733SEric W. Biederman struct ctl_table sysctl_mount_point[] = { 35f9bd6733SEric W. Biederman { } 36f9bd6733SEric W. Biederman }; 37f9bd6733SEric W. Biederman 38*ee9efac4SLuis Chamberlain /** 39*ee9efac4SLuis Chamberlain * register_sysctl_mount_point() - registers a sysctl mount point 40*ee9efac4SLuis Chamberlain * @path: path for the mount point 41*ee9efac4SLuis Chamberlain * 42*ee9efac4SLuis Chamberlain * Used to create a permanently empty directory to serve as mount point. 43*ee9efac4SLuis Chamberlain * There are some subtle but important permission checks this allows in the 44*ee9efac4SLuis Chamberlain * case of unprivileged mounts. 45*ee9efac4SLuis Chamberlain */ 46*ee9efac4SLuis Chamberlain struct ctl_table_header *register_sysctl_mount_point(const char *path) 47*ee9efac4SLuis Chamberlain { 48*ee9efac4SLuis Chamberlain return register_sysctl(path, sysctl_mount_point); 49*ee9efac4SLuis Chamberlain } 50*ee9efac4SLuis Chamberlain EXPORT_SYMBOL(register_sysctl_mount_point); 51*ee9efac4SLuis Chamberlain 52f9bd6733SEric W. Biederman static bool is_empty_dir(struct ctl_table_header *head) 53f9bd6733SEric W. Biederman { 54f9bd6733SEric W. Biederman return head->ctl_table[0].child == sysctl_mount_point; 55f9bd6733SEric W. Biederman } 56f9bd6733SEric W. Biederman 57f9bd6733SEric W. Biederman static void set_empty_dir(struct ctl_dir *dir) 58f9bd6733SEric W. Biederman { 59f9bd6733SEric W. Biederman dir->header.ctl_table[0].child = sysctl_mount_point; 60f9bd6733SEric W. Biederman } 61f9bd6733SEric W. Biederman 62f9bd6733SEric W. Biederman static void clear_empty_dir(struct ctl_dir *dir) 63f9bd6733SEric W. Biederman 64f9bd6733SEric W. Biederman { 65f9bd6733SEric W. Biederman dir->header.ctl_table[0].child = NULL; 66f9bd6733SEric W. Biederman } 67f9bd6733SEric W. Biederman 68f1ecf068SLucas De Marchi void proc_sys_poll_notify(struct ctl_table_poll *poll) 69f1ecf068SLucas De Marchi { 70f1ecf068SLucas De Marchi if (!poll) 71f1ecf068SLucas De Marchi return; 72f1ecf068SLucas De Marchi 73f1ecf068SLucas De Marchi atomic_inc(&poll->event); 74f1ecf068SLucas De Marchi wake_up_interruptible(&poll->wait); 75f1ecf068SLucas De Marchi } 76f1ecf068SLucas De Marchi 77a194558eSEric W. Biederman static struct ctl_table root_table[] = { 78a194558eSEric W. Biederman { 79a194558eSEric W. Biederman .procname = "", 807ec66d06SEric W. Biederman .mode = S_IFDIR|S_IRUGO|S_IXUGO, 81a194558eSEric W. Biederman }, 82a194558eSEric W. Biederman { } 83a194558eSEric W. Biederman }; 840e47c99dSEric W. Biederman static struct ctl_table_root sysctl_table_root = { 850e47c99dSEric W. Biederman .default_set.dir.header = { 861f87f0b5SEric W. Biederman {{.count = 1, 87938aaa4fSEric W. Biederman .nreg = 1, 88ac13ac6fSEric W. Biederman .ctl_table = root_table }}, 890e47c99dSEric W. Biederman .ctl_table_arg = root_table, 901f87f0b5SEric W. Biederman .root = &sysctl_table_root, 911f87f0b5SEric W. Biederman .set = &sysctl_table_root.default_set, 927ec66d06SEric W. Biederman }, 931f87f0b5SEric W. Biederman }; 941f87f0b5SEric W. Biederman 951f87f0b5SEric W. Biederman static DEFINE_SPINLOCK(sysctl_lock); 961f87f0b5SEric W. Biederman 977ec66d06SEric W. Biederman static void drop_sysctl_table(struct ctl_table_header *header); 980e47c99dSEric W. Biederman static int sysctl_follow_link(struct ctl_table_header **phead, 9913bcc6a2SEric W. Biederman struct ctl_table **pentry); 1000e47c99dSEric W. Biederman static int insert_links(struct ctl_table_header *head); 1010e47c99dSEric W. Biederman static void put_links(struct ctl_table_header *header); 1027ec66d06SEric W. Biederman 1036980128fSEric W. Biederman static void sysctl_print_dir(struct ctl_dir *dir) 1046980128fSEric W. Biederman { 1056980128fSEric W. Biederman if (dir->header.parent) 1066980128fSEric W. Biederman sysctl_print_dir(dir->header.parent); 10787ebdc00SAndrew Morton pr_cont("%s/", dir->header.ctl_table[0].procname); 1086980128fSEric W. Biederman } 1096980128fSEric W. Biederman 110076c3eedSEric W. Biederman static int namecmp(const char *name1, int len1, const char *name2, int len2) 111076c3eedSEric W. Biederman { 112076c3eedSEric W. Biederman int cmp; 113076c3eedSEric W. Biederman 114d8fc9b66SMasahiro Yamada cmp = memcmp(name1, name2, min(len1, len2)); 115076c3eedSEric W. Biederman if (cmp == 0) 116076c3eedSEric W. Biederman cmp = len1 - len2; 117076c3eedSEric W. Biederman return cmp; 118076c3eedSEric W. Biederman } 119076c3eedSEric W. Biederman 12060f126d9SEric W. Biederman /* Called under sysctl_lock */ 121076c3eedSEric W. Biederman static struct ctl_table *find_entry(struct ctl_table_header **phead, 1220e47c99dSEric W. Biederman struct ctl_dir *dir, const char *name, int namelen) 123076c3eedSEric W. Biederman { 124076c3eedSEric W. Biederman struct ctl_table_header *head; 125076c3eedSEric W. Biederman struct ctl_table *entry; 126ac13ac6fSEric W. Biederman struct rb_node *node = dir->root.rb_node; 127076c3eedSEric W. Biederman 128ac13ac6fSEric W. Biederman while (node) 129ac13ac6fSEric W. Biederman { 130ac13ac6fSEric W. Biederman struct ctl_node *ctl_node; 131ac13ac6fSEric W. Biederman const char *procname; 132ac13ac6fSEric W. Biederman int cmp; 133ac13ac6fSEric W. Biederman 134ac13ac6fSEric W. Biederman ctl_node = rb_entry(node, struct ctl_node, node); 135ac13ac6fSEric W. Biederman head = ctl_node->header; 136ac13ac6fSEric W. Biederman entry = &head->ctl_table[ctl_node - head->node]; 137ac13ac6fSEric W. Biederman procname = entry->procname; 138ac13ac6fSEric W. Biederman 139ac13ac6fSEric W. Biederman cmp = namecmp(name, namelen, procname, strlen(procname)); 140ac13ac6fSEric W. Biederman if (cmp < 0) 141ac13ac6fSEric W. Biederman node = node->rb_left; 142ac13ac6fSEric W. Biederman else if (cmp > 0) 143ac13ac6fSEric W. Biederman node = node->rb_right; 144ac13ac6fSEric W. Biederman else { 145076c3eedSEric W. Biederman *phead = head; 146076c3eedSEric W. Biederman return entry; 147076c3eedSEric W. Biederman } 148076c3eedSEric W. Biederman } 149076c3eedSEric W. Biederman return NULL; 150076c3eedSEric W. Biederman } 151076c3eedSEric W. Biederman 152ac13ac6fSEric W. Biederman static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry) 153ac13ac6fSEric W. Biederman { 154ac13ac6fSEric W. Biederman struct rb_node *node = &head->node[entry - head->ctl_table].node; 155ac13ac6fSEric W. Biederman struct rb_node **p = &head->parent->root.rb_node; 156ac13ac6fSEric W. Biederman struct rb_node *parent = NULL; 157ac13ac6fSEric W. Biederman const char *name = entry->procname; 158ac13ac6fSEric W. Biederman int namelen = strlen(name); 159ac13ac6fSEric W. Biederman 160ac13ac6fSEric W. Biederman while (*p) { 161ac13ac6fSEric W. Biederman struct ctl_table_header *parent_head; 162ac13ac6fSEric W. Biederman struct ctl_table *parent_entry; 163ac13ac6fSEric W. Biederman struct ctl_node *parent_node; 164ac13ac6fSEric W. Biederman const char *parent_name; 165ac13ac6fSEric W. Biederman int cmp; 166ac13ac6fSEric W. Biederman 167ac13ac6fSEric W. Biederman parent = *p; 168ac13ac6fSEric W. Biederman parent_node = rb_entry(parent, struct ctl_node, node); 169ac13ac6fSEric W. Biederman parent_head = parent_node->header; 170ac13ac6fSEric W. Biederman parent_entry = &parent_head->ctl_table[parent_node - parent_head->node]; 171ac13ac6fSEric W. Biederman parent_name = parent_entry->procname; 172ac13ac6fSEric W. Biederman 173ac13ac6fSEric W. Biederman cmp = namecmp(name, namelen, parent_name, strlen(parent_name)); 174ac13ac6fSEric W. Biederman if (cmp < 0) 175ac13ac6fSEric W. Biederman p = &(*p)->rb_left; 176ac13ac6fSEric W. Biederman else if (cmp > 0) 177ac13ac6fSEric W. Biederman p = &(*p)->rb_right; 178ac13ac6fSEric W. Biederman else { 17987ebdc00SAndrew Morton pr_err("sysctl duplicate entry: "); 180ac13ac6fSEric W. Biederman sysctl_print_dir(head->parent); 181153ee1c4SGeert Uytterhoeven pr_cont("%s\n", entry->procname); 182ac13ac6fSEric W. Biederman return -EEXIST; 183ac13ac6fSEric W. Biederman } 184ac13ac6fSEric W. Biederman } 185ac13ac6fSEric W. Biederman 186ac13ac6fSEric W. Biederman rb_link_node(node, parent, p); 187ea5272f5SMichel Lespinasse rb_insert_color(node, &head->parent->root); 188ac13ac6fSEric W. Biederman return 0; 189ac13ac6fSEric W. Biederman } 190ac13ac6fSEric W. Biederman 191ac13ac6fSEric W. Biederman static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry) 192ac13ac6fSEric W. Biederman { 193ac13ac6fSEric W. Biederman struct rb_node *node = &head->node[entry - head->ctl_table].node; 194ac13ac6fSEric W. Biederman 195ac13ac6fSEric W. Biederman rb_erase(node, &head->parent->root); 196ac13ac6fSEric W. Biederman } 197ac13ac6fSEric W. Biederman 198e0d04529SEric W. Biederman static void init_header(struct ctl_table_header *head, 199e0d04529SEric W. Biederman struct ctl_table_root *root, struct ctl_table_set *set, 200ac13ac6fSEric W. Biederman struct ctl_node *node, struct ctl_table *table) 201e0d04529SEric W. Biederman { 2027ec66d06SEric W. Biederman head->ctl_table = table; 203e0d04529SEric W. Biederman head->ctl_table_arg = table; 204e0d04529SEric W. Biederman head->used = 0; 205e0d04529SEric W. Biederman head->count = 1; 206e0d04529SEric W. Biederman head->nreg = 1; 207e0d04529SEric W. Biederman head->unregistering = NULL; 208e0d04529SEric W. Biederman head->root = root; 209e0d04529SEric W. Biederman head->set = set; 210e0d04529SEric W. Biederman head->parent = NULL; 211ac13ac6fSEric W. Biederman head->node = node; 2122fd1d2c4SEric W. Biederman INIT_HLIST_HEAD(&head->inodes); 213ac13ac6fSEric W. Biederman if (node) { 214ac13ac6fSEric W. Biederman struct ctl_table *entry; 2154c199a93SMichel Lespinasse for (entry = table; entry->procname; entry++, node++) 216ac13ac6fSEric W. Biederman node->header = head; 217ac13ac6fSEric W. Biederman } 218ac13ac6fSEric W. Biederman } 219e0d04529SEric W. Biederman 2208425d6aaSEric W. Biederman static void erase_header(struct ctl_table_header *head) 2218425d6aaSEric W. Biederman { 222ac13ac6fSEric W. Biederman struct ctl_table *entry; 223ac13ac6fSEric W. Biederman for (entry = head->ctl_table; entry->procname; entry++) 224ac13ac6fSEric W. Biederman erase_entry(head, entry); 2258425d6aaSEric W. Biederman } 2268425d6aaSEric W. Biederman 2270e47c99dSEric W. Biederman static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) 2288425d6aaSEric W. Biederman { 229ac13ac6fSEric W. Biederman struct ctl_table *entry; 2300e47c99dSEric W. Biederman int err; 2310e47c99dSEric W. Biederman 232f9bd6733SEric W. Biederman /* Is this a permanently empty directory? */ 233f9bd6733SEric W. Biederman if (is_empty_dir(&dir->header)) 234f9bd6733SEric W. Biederman return -EROFS; 235f9bd6733SEric W. Biederman 236f9bd6733SEric W. Biederman /* Am I creating a permanently empty directory? */ 237f9bd6733SEric W. Biederman if (header->ctl_table == sysctl_mount_point) { 238f9bd6733SEric W. Biederman if (!RB_EMPTY_ROOT(&dir->root)) 239f9bd6733SEric W. Biederman return -EINVAL; 240f9bd6733SEric W. Biederman set_empty_dir(dir); 241f9bd6733SEric W. Biederman } 242f9bd6733SEric W. Biederman 2430e47c99dSEric W. Biederman dir->header.nreg++; 2447ec66d06SEric W. Biederman header->parent = dir; 2450e47c99dSEric W. Biederman err = insert_links(header); 2460e47c99dSEric W. Biederman if (err) 2470e47c99dSEric W. Biederman goto fail_links; 248ac13ac6fSEric W. Biederman for (entry = header->ctl_table; entry->procname; entry++) { 249ac13ac6fSEric W. Biederman err = insert_entry(header, entry); 250ac13ac6fSEric W. Biederman if (err) 251ac13ac6fSEric W. Biederman goto fail; 252ac13ac6fSEric W. Biederman } 2530e47c99dSEric W. Biederman return 0; 254ac13ac6fSEric W. Biederman fail: 255ac13ac6fSEric W. Biederman erase_header(header); 256ac13ac6fSEric W. Biederman put_links(header); 2570e47c99dSEric W. Biederman fail_links: 258f9bd6733SEric W. Biederman if (header->ctl_table == sysctl_mount_point) 259f9bd6733SEric W. Biederman clear_empty_dir(dir); 2600e47c99dSEric W. Biederman header->parent = NULL; 2610e47c99dSEric W. Biederman drop_sysctl_table(&dir->header); 2620e47c99dSEric W. Biederman return err; 2638425d6aaSEric W. Biederman } 2648425d6aaSEric W. Biederman 2651f87f0b5SEric W. Biederman /* called under sysctl_lock */ 2661f87f0b5SEric W. Biederman static int use_table(struct ctl_table_header *p) 2671f87f0b5SEric W. Biederman { 2681f87f0b5SEric W. Biederman if (unlikely(p->unregistering)) 2691f87f0b5SEric W. Biederman return 0; 2701f87f0b5SEric W. Biederman p->used++; 2711f87f0b5SEric W. Biederman return 1; 2721f87f0b5SEric W. Biederman } 2731f87f0b5SEric W. Biederman 2741f87f0b5SEric W. Biederman /* called under sysctl_lock */ 2751f87f0b5SEric W. Biederman static void unuse_table(struct ctl_table_header *p) 2761f87f0b5SEric W. Biederman { 2771f87f0b5SEric W. Biederman if (!--p->used) 2781f87f0b5SEric W. Biederman if (unlikely(p->unregistering)) 2791f87f0b5SEric W. Biederman complete(p->unregistering); 2801f87f0b5SEric W. Biederman } 2811f87f0b5SEric W. Biederman 282f90f3cafSEric W. Biederman static void proc_sys_invalidate_dcache(struct ctl_table_header *head) 283d6cffbbeSKonstantin Khlebnikov { 284f90f3cafSEric W. Biederman proc_invalidate_siblings_dcache(&head->inodes, &sysctl_lock); 285d6cffbbeSKonstantin Khlebnikov } 286d6cffbbeSKonstantin Khlebnikov 2871f87f0b5SEric W. Biederman /* called under sysctl_lock, will reacquire if has to wait */ 2881f87f0b5SEric W. Biederman static void start_unregistering(struct ctl_table_header *p) 2891f87f0b5SEric W. Biederman { 2901f87f0b5SEric W. Biederman /* 2911f87f0b5SEric W. Biederman * if p->used is 0, nobody will ever touch that entry again; 2921f87f0b5SEric W. Biederman * we'll eliminate all paths to it before dropping sysctl_lock 2931f87f0b5SEric W. Biederman */ 2941f87f0b5SEric W. Biederman if (unlikely(p->used)) { 2951f87f0b5SEric W. Biederman struct completion wait; 2961f87f0b5SEric W. Biederman init_completion(&wait); 2971f87f0b5SEric W. Biederman p->unregistering = &wait; 2981f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 2991f87f0b5SEric W. Biederman wait_for_completion(&wait); 3001f87f0b5SEric W. Biederman } else { 3011f87f0b5SEric W. Biederman /* anything non-NULL; we'll never dereference it */ 3021f87f0b5SEric W. Biederman p->unregistering = ERR_PTR(-EINVAL); 303ace0c791SEric W. Biederman spin_unlock(&sysctl_lock); 3041f87f0b5SEric W. Biederman } 3051f87f0b5SEric W. Biederman /* 306f90f3cafSEric W. Biederman * Invalidate dentries for unregistered sysctls: namespaced sysctls 307d6cffbbeSKonstantin Khlebnikov * can have duplicate names and contaminate dcache very badly. 308d6cffbbeSKonstantin Khlebnikov */ 309f90f3cafSEric W. Biederman proc_sys_invalidate_dcache(p); 310d6cffbbeSKonstantin Khlebnikov /* 3111f87f0b5SEric W. Biederman * do not remove from the list until nobody holds it; walking the 3121f87f0b5SEric W. Biederman * list in do_sysctl() relies on that. 3131f87f0b5SEric W. Biederman */ 314ace0c791SEric W. Biederman spin_lock(&sysctl_lock); 3158425d6aaSEric W. Biederman erase_header(p); 3161f87f0b5SEric W. Biederman } 3171f87f0b5SEric W. Biederman 3181f87f0b5SEric W. Biederman static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) 3191f87f0b5SEric W. Biederman { 320ab4a1f24SPrasad Joshi BUG_ON(!head); 3211f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 3221f87f0b5SEric W. Biederman if (!use_table(head)) 3231f87f0b5SEric W. Biederman head = ERR_PTR(-ENOENT); 3241f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 3251f87f0b5SEric W. Biederman return head; 3261f87f0b5SEric W. Biederman } 3271f87f0b5SEric W. Biederman 3281f87f0b5SEric W. Biederman static void sysctl_head_finish(struct ctl_table_header *head) 3291f87f0b5SEric W. Biederman { 3301f87f0b5SEric W. Biederman if (!head) 3311f87f0b5SEric W. Biederman return; 3321f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 3331f87f0b5SEric W. Biederman unuse_table(head); 3341f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 3351f87f0b5SEric W. Biederman } 3361f87f0b5SEric W. Biederman 3371f87f0b5SEric W. Biederman static struct ctl_table_set * 33813bcc6a2SEric W. Biederman lookup_header_set(struct ctl_table_root *root) 3391f87f0b5SEric W. Biederman { 3401f87f0b5SEric W. Biederman struct ctl_table_set *set = &root->default_set; 3411f87f0b5SEric W. Biederman if (root->lookup) 34213bcc6a2SEric W. Biederman set = root->lookup(root); 3431f87f0b5SEric W. Biederman return set; 3441f87f0b5SEric W. Biederman } 3451f87f0b5SEric W. Biederman 346076c3eedSEric W. Biederman static struct ctl_table *lookup_entry(struct ctl_table_header **phead, 3477ec66d06SEric W. Biederman struct ctl_dir *dir, 348076c3eedSEric W. Biederman const char *name, int namelen) 349076c3eedSEric W. Biederman { 350076c3eedSEric W. Biederman struct ctl_table_header *head; 351076c3eedSEric W. Biederman struct ctl_table *entry; 352076c3eedSEric W. Biederman 353076c3eedSEric W. Biederman spin_lock(&sysctl_lock); 3540e47c99dSEric W. Biederman entry = find_entry(&head, dir, name, namelen); 355076c3eedSEric W. Biederman if (entry && use_table(head)) 356076c3eedSEric W. Biederman *phead = head; 357076c3eedSEric W. Biederman else 358076c3eedSEric W. Biederman entry = NULL; 359076c3eedSEric W. Biederman spin_unlock(&sysctl_lock); 360076c3eedSEric W. Biederman return entry; 361076c3eedSEric W. Biederman } 362076c3eedSEric W. Biederman 363ac13ac6fSEric W. Biederman static struct ctl_node *first_usable_entry(struct rb_node *node) 3641f87f0b5SEric W. Biederman { 365ac13ac6fSEric W. Biederman struct ctl_node *ctl_node; 3661f87f0b5SEric W. Biederman 367ac13ac6fSEric W. Biederman for (;node; node = rb_next(node)) { 368ac13ac6fSEric W. Biederman ctl_node = rb_entry(node, struct ctl_node, node); 369ac13ac6fSEric W. Biederman if (use_table(ctl_node->header)) 370ac13ac6fSEric W. Biederman return ctl_node; 3711f87f0b5SEric W. Biederman } 3721f87f0b5SEric W. Biederman return NULL; 3731f87f0b5SEric W. Biederman } 3741f87f0b5SEric W. Biederman 3757ec66d06SEric W. Biederman static void first_entry(struct ctl_dir *dir, 3766a75ce16SEric W. Biederman struct ctl_table_header **phead, struct ctl_table **pentry) 3771f87f0b5SEric W. Biederman { 378ac13ac6fSEric W. Biederman struct ctl_table_header *head = NULL; 3797ec66d06SEric W. Biederman struct ctl_table *entry = NULL; 380ac13ac6fSEric W. Biederman struct ctl_node *ctl_node; 3816a75ce16SEric W. Biederman 3826a75ce16SEric W. Biederman spin_lock(&sysctl_lock); 383ac13ac6fSEric W. Biederman ctl_node = first_usable_entry(rb_first(&dir->root)); 3846a75ce16SEric W. Biederman spin_unlock(&sysctl_lock); 385ac13ac6fSEric W. Biederman if (ctl_node) { 386ac13ac6fSEric W. Biederman head = ctl_node->header; 387ac13ac6fSEric W. Biederman entry = &head->ctl_table[ctl_node - head->node]; 388ac13ac6fSEric W. Biederman } 3896a75ce16SEric W. Biederman *phead = head; 3906a75ce16SEric W. Biederman *pentry = entry; 3916a75ce16SEric W. Biederman } 3926a75ce16SEric W. Biederman 3937ec66d06SEric W. Biederman static void next_entry(struct ctl_table_header **phead, struct ctl_table **pentry) 3946a75ce16SEric W. Biederman { 3956a75ce16SEric W. Biederman struct ctl_table_header *head = *phead; 3966a75ce16SEric W. Biederman struct ctl_table *entry = *pentry; 397ac13ac6fSEric W. Biederman struct ctl_node *ctl_node = &head->node[entry - head->ctl_table]; 3986a75ce16SEric W. Biederman 3996a75ce16SEric W. Biederman spin_lock(&sysctl_lock); 4006a75ce16SEric W. Biederman unuse_table(head); 401ac13ac6fSEric W. Biederman 402ac13ac6fSEric W. Biederman ctl_node = first_usable_entry(rb_next(&ctl_node->node)); 4036a75ce16SEric W. Biederman spin_unlock(&sysctl_lock); 404ac13ac6fSEric W. Biederman head = NULL; 405ac13ac6fSEric W. Biederman if (ctl_node) { 406ac13ac6fSEric W. Biederman head = ctl_node->header; 407ac13ac6fSEric W. Biederman entry = &head->ctl_table[ctl_node - head->node]; 4086a75ce16SEric W. Biederman } 4096a75ce16SEric W. Biederman *phead = head; 4106a75ce16SEric W. Biederman *pentry = entry; 4111f87f0b5SEric W. Biederman } 4121f87f0b5SEric W. Biederman 4131f87f0b5SEric W. Biederman /* 4141f87f0b5SEric W. Biederman * sysctl_perm does NOT grant the superuser all rights automatically, because 4151f87f0b5SEric W. Biederman * some sysctl variables are readonly even to root. 4161f87f0b5SEric W. Biederman */ 4171f87f0b5SEric W. Biederman 4181f87f0b5SEric W. Biederman static int test_perm(int mode, int op) 4191f87f0b5SEric W. Biederman { 420091bd3eaSEric W. Biederman if (uid_eq(current_euid(), GLOBAL_ROOT_UID)) 4211f87f0b5SEric W. Biederman mode >>= 6; 422091bd3eaSEric W. Biederman else if (in_egroup_p(GLOBAL_ROOT_GID)) 4231f87f0b5SEric W. Biederman mode >>= 3; 4241f87f0b5SEric W. Biederman if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) 4251f87f0b5SEric W. Biederman return 0; 4261f87f0b5SEric W. Biederman return -EACCES; 4271f87f0b5SEric W. Biederman } 4281f87f0b5SEric W. Biederman 42973f7ef43SEric W. Biederman static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, int op) 4301f87f0b5SEric W. Biederman { 43173f7ef43SEric W. Biederman struct ctl_table_root *root = head->root; 4321f87f0b5SEric W. Biederman int mode; 4331f87f0b5SEric W. Biederman 4341f87f0b5SEric W. Biederman if (root->permissions) 43573f7ef43SEric W. Biederman mode = root->permissions(head, table); 4361f87f0b5SEric W. Biederman else 4371f87f0b5SEric W. Biederman mode = table->mode; 4381f87f0b5SEric W. Biederman 4391f87f0b5SEric W. Biederman return test_perm(mode, op); 4401f87f0b5SEric W. Biederman } 4411f87f0b5SEric W. Biederman 4429043476fSAl Viro static struct inode *proc_sys_make_inode(struct super_block *sb, 4439043476fSAl Viro struct ctl_table_header *head, struct ctl_table *table) 44477b14db5SEric W. Biederman { 445e79c6a4fSDmitry Torokhov struct ctl_table_root *root = head->root; 44677b14db5SEric W. Biederman struct inode *inode; 4479043476fSAl Viro struct proc_inode *ei; 44877b14db5SEric W. Biederman 4499043476fSAl Viro inode = new_inode(sb); 45077b14db5SEric W. Biederman if (!inode) 451ea5751ccSIvan Delalande return ERR_PTR(-ENOMEM); 45277b14db5SEric W. Biederman 45385fe4025SChristoph Hellwig inode->i_ino = get_next_ino(); 45485fe4025SChristoph Hellwig 45577b14db5SEric W. Biederman ei = PROC_I(inode); 4569043476fSAl Viro 457d6cffbbeSKonstantin Khlebnikov spin_lock(&sysctl_lock); 458ace0c791SEric W. Biederman if (unlikely(head->unregistering)) { 459ace0c791SEric W. Biederman spin_unlock(&sysctl_lock); 460ace0c791SEric W. Biederman iput(inode); 461ea5751ccSIvan Delalande return ERR_PTR(-ENOENT); 462ace0c791SEric W. Biederman } 463ace0c791SEric W. Biederman ei->sysctl = head; 464ace0c791SEric W. Biederman ei->sysctl_entry = table; 4650afa5ca8SEric W. Biederman hlist_add_head_rcu(&ei->sibling_inodes, &head->inodes); 466d6cffbbeSKonstantin Khlebnikov head->count++; 467d6cffbbeSKonstantin Khlebnikov spin_unlock(&sysctl_lock); 468d6cffbbeSKonstantin Khlebnikov 469078cd827SDeepa Dinamani inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 4709043476fSAl Viro inode->i_mode = table->mode; 4717ec66d06SEric W. Biederman if (!S_ISDIR(table->mode)) { 4729043476fSAl Viro inode->i_mode |= S_IFREG; 47377b14db5SEric W. Biederman inode->i_op = &proc_sys_inode_operations; 47477b14db5SEric W. Biederman inode->i_fop = &proc_sys_file_operations; 4759043476fSAl Viro } else { 4769043476fSAl Viro inode->i_mode |= S_IFDIR; 4779043476fSAl Viro inode->i_op = &proc_sys_dir_operations; 4789043476fSAl Viro inode->i_fop = &proc_sys_dir_file_operations; 479f9bd6733SEric W. Biederman if (is_empty_dir(head)) 480f9bd6733SEric W. Biederman make_empty_dir_inode(inode); 4819043476fSAl Viro } 482e79c6a4fSDmitry Torokhov 483e79c6a4fSDmitry Torokhov if (root->set_ownership) 484e79c6a4fSDmitry Torokhov root->set_ownership(head, table, &inode->i_uid, &inode->i_gid); 4855ec27ec7SRadoslaw Burny else { 4865ec27ec7SRadoslaw Burny inode->i_uid = GLOBAL_ROOT_UID; 4875ec27ec7SRadoslaw Burny inode->i_gid = GLOBAL_ROOT_GID; 4885ec27ec7SRadoslaw Burny } 489e79c6a4fSDmitry Torokhov 49077b14db5SEric W. Biederman return inode; 49177b14db5SEric W. Biederman } 49277b14db5SEric W. Biederman 493d6cffbbeSKonstantin Khlebnikov void proc_sys_evict_inode(struct inode *inode, struct ctl_table_header *head) 494d6cffbbeSKonstantin Khlebnikov { 495d6cffbbeSKonstantin Khlebnikov spin_lock(&sysctl_lock); 4960afa5ca8SEric W. Biederman hlist_del_init_rcu(&PROC_I(inode)->sibling_inodes); 497d6cffbbeSKonstantin Khlebnikov if (!--head->count) 498d6cffbbeSKonstantin Khlebnikov kfree_rcu(head, rcu); 499d6cffbbeSKonstantin Khlebnikov spin_unlock(&sysctl_lock); 500d6cffbbeSKonstantin Khlebnikov } 501d6cffbbeSKonstantin Khlebnikov 50281324364SAdrian Bunk static struct ctl_table_header *grab_header(struct inode *inode) 50377b14db5SEric W. Biederman { 5043cc3e046SEric W. Biederman struct ctl_table_header *head = PROC_I(inode)->sysctl; 5053cc3e046SEric W. Biederman if (!head) 5060e47c99dSEric W. Biederman head = &sysctl_table_root.default_set.dir.header; 5073cc3e046SEric W. Biederman return sysctl_head_grab(head); 50877b14db5SEric W. Biederman } 50977b14db5SEric W. Biederman 51077b14db5SEric W. Biederman static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, 51100cd8dd3SAl Viro unsigned int flags) 51277b14db5SEric W. Biederman { 5139043476fSAl Viro struct ctl_table_header *head = grab_header(dir); 5149043476fSAl Viro struct ctl_table_header *h = NULL; 515dc12e909SAl Viro const struct qstr *name = &dentry->d_name; 5169043476fSAl Viro struct ctl_table *p; 51777b14db5SEric W. Biederman struct inode *inode; 5189043476fSAl Viro struct dentry *err = ERR_PTR(-ENOENT); 5197ec66d06SEric W. Biederman struct ctl_dir *ctl_dir; 5200e47c99dSEric W. Biederman int ret; 52177b14db5SEric W. Biederman 5229043476fSAl Viro if (IS_ERR(head)) 5239043476fSAl Viro return ERR_CAST(head); 5249043476fSAl Viro 5257ec66d06SEric W. Biederman ctl_dir = container_of(head, struct ctl_dir, header); 5269043476fSAl Viro 5277ec66d06SEric W. Biederman p = lookup_entry(&h, ctl_dir, name->name, name->len); 5289043476fSAl Viro if (!p) 52977b14db5SEric W. Biederman goto out; 53077b14db5SEric W. Biederman 5314e757320SEric W. Biederman if (S_ISLNK(p->mode)) { 53213bcc6a2SEric W. Biederman ret = sysctl_follow_link(&h, &p); 5330e47c99dSEric W. Biederman err = ERR_PTR(ret); 5340e47c99dSEric W. Biederman if (ret) 5350e47c99dSEric W. Biederman goto out; 5364e757320SEric W. Biederman } 5370e47c99dSEric W. Biederman 5389043476fSAl Viro inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); 539ea5751ccSIvan Delalande if (IS_ERR(inode)) { 540ea5751ccSIvan Delalande err = ERR_CAST(inode); 54177b14db5SEric W. Biederman goto out; 542ea5751ccSIvan Delalande } 54377b14db5SEric W. Biederman 544fb045adbSNick Piggin d_set_d_op(dentry, &proc_sys_dentry_operations); 545888e2b03SAl Viro err = d_splice_alias(inode, dentry); 54677b14db5SEric W. Biederman 54777b14db5SEric W. Biederman out: 5486bf61045SFrancesco Ruggeri if (h) 5496bf61045SFrancesco Ruggeri sysctl_head_finish(h); 55077b14db5SEric W. Biederman sysctl_head_finish(head); 55177b14db5SEric W. Biederman return err; 55277b14db5SEric W. Biederman } 55377b14db5SEric W. Biederman 5544bd6a735SMatthew Wilcox (Oracle) static ssize_t proc_sys_call_handler(struct kiocb *iocb, struct iov_iter *iter, 5554bd6a735SMatthew Wilcox (Oracle) int write) 55677b14db5SEric W. Biederman { 5574bd6a735SMatthew Wilcox (Oracle) struct inode *inode = file_inode(iocb->ki_filp); 5589043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 5599043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 5604bd6a735SMatthew Wilcox (Oracle) size_t count = iov_iter_count(iter); 5614bd6a735SMatthew Wilcox (Oracle) char *kbuf; 5622a2da53bSDavid Howells ssize_t error; 56377b14db5SEric W. Biederman 5649043476fSAl Viro if (IS_ERR(head)) 5659043476fSAl Viro return PTR_ERR(head); 56677b14db5SEric W. Biederman 56777b14db5SEric W. Biederman /* 56877b14db5SEric W. Biederman * At this point we know that the sysctl was not unregistered 56977b14db5SEric W. Biederman * and won't be until we finish. 57077b14db5SEric W. Biederman */ 57177b14db5SEric W. Biederman error = -EPERM; 57273f7ef43SEric W. Biederman if (sysctl_perm(head, table, write ? MAY_WRITE : MAY_READ)) 57377b14db5SEric W. Biederman goto out; 57477b14db5SEric W. Biederman 5759043476fSAl Viro /* if that can happen at all, it should be -EINVAL, not -EISDIR */ 5769043476fSAl Viro error = -EINVAL; 5779043476fSAl Viro if (!table->proc_handler) 5789043476fSAl Viro goto out; 5799043476fSAl Viro 580ef9d965bSChristoph Hellwig /* don't even try if the size is too large */ 581d4d80e69SMatthew Wilcox (Oracle) error = -ENOMEM; 582d4d80e69SMatthew Wilcox (Oracle) if (count >= KMALLOC_MAX_SIZE) 583d4d80e69SMatthew Wilcox (Oracle) goto out; 58445089437SJosef Bacik kbuf = kvzalloc(count + 1, GFP_KERNEL); 58532927393SChristoph Hellwig if (!kbuf) 58632927393SChristoph Hellwig goto out; 5874bd6a735SMatthew Wilcox (Oracle) 5884bd6a735SMatthew Wilcox (Oracle) if (write) { 5894bd6a735SMatthew Wilcox (Oracle) error = -EFAULT; 5904bd6a735SMatthew Wilcox (Oracle) if (!copy_from_iter_full(kbuf, count, iter)) 5914bd6a735SMatthew Wilcox (Oracle) goto out_free_buf; 5924bd6a735SMatthew Wilcox (Oracle) kbuf[count] = '\0'; 5934e63acdfSAndrey Ignatov } 5944e63acdfSAndrey Ignatov 59532927393SChristoph Hellwig error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, &kbuf, &count, 5964bd6a735SMatthew Wilcox (Oracle) &iocb->ki_pos); 59732927393SChristoph Hellwig if (error) 59832927393SChristoph Hellwig goto out_free_buf; 59932927393SChristoph Hellwig 60032927393SChristoph Hellwig /* careful: calling conventions are nasty here */ 6014bd6a735SMatthew Wilcox (Oracle) error = table->proc_handler(table, write, kbuf, &count, &iocb->ki_pos); 60232927393SChristoph Hellwig if (error) 60332927393SChristoph Hellwig goto out_free_buf; 60432927393SChristoph Hellwig 60532927393SChristoph Hellwig if (!write) { 60632927393SChristoph Hellwig error = -EFAULT; 6074bd6a735SMatthew Wilcox (Oracle) if (copy_to_iter(kbuf, count, iter) < count) 60832927393SChristoph Hellwig goto out_free_buf; 60932927393SChristoph Hellwig } 61032927393SChristoph Hellwig 6114e63acdfSAndrey Ignatov error = count; 61232927393SChristoph Hellwig out_free_buf: 61345089437SJosef Bacik kvfree(kbuf); 61477b14db5SEric W. Biederman out: 61577b14db5SEric W. Biederman sysctl_head_finish(head); 61677b14db5SEric W. Biederman 61777b14db5SEric W. Biederman return error; 61877b14db5SEric W. Biederman } 61977b14db5SEric W. Biederman 6204bd6a735SMatthew Wilcox (Oracle) static ssize_t proc_sys_read(struct kiocb *iocb, struct iov_iter *iter) 6217708bfb1SPavel Emelyanov { 6224bd6a735SMatthew Wilcox (Oracle) return proc_sys_call_handler(iocb, iter, 0); 6237708bfb1SPavel Emelyanov } 6247708bfb1SPavel Emelyanov 6254bd6a735SMatthew Wilcox (Oracle) static ssize_t proc_sys_write(struct kiocb *iocb, struct iov_iter *iter) 62677b14db5SEric W. Biederman { 6274bd6a735SMatthew Wilcox (Oracle) return proc_sys_call_handler(iocb, iter, 1); 62877b14db5SEric W. Biederman } 62977b14db5SEric W. Biederman 630f1ecf068SLucas De Marchi static int proc_sys_open(struct inode *inode, struct file *filp) 631f1ecf068SLucas De Marchi { 6324e474a00SLucas De Marchi struct ctl_table_header *head = grab_header(inode); 633f1ecf068SLucas De Marchi struct ctl_table *table = PROC_I(inode)->sysctl_entry; 634f1ecf068SLucas De Marchi 6354e474a00SLucas De Marchi /* sysctl was unregistered */ 6364e474a00SLucas De Marchi if (IS_ERR(head)) 6374e474a00SLucas De Marchi return PTR_ERR(head); 6384e474a00SLucas De Marchi 639f1ecf068SLucas De Marchi if (table->poll) 640f1ecf068SLucas De Marchi filp->private_data = proc_sys_poll_event(table->poll); 641f1ecf068SLucas De Marchi 6424e474a00SLucas De Marchi sysctl_head_finish(head); 6434e474a00SLucas De Marchi 644f1ecf068SLucas De Marchi return 0; 645f1ecf068SLucas De Marchi } 646f1ecf068SLucas De Marchi 647076ccb76SAl Viro static __poll_t proc_sys_poll(struct file *filp, poll_table *wait) 648f1ecf068SLucas De Marchi { 649496ad9aaSAl Viro struct inode *inode = file_inode(filp); 6504e474a00SLucas De Marchi struct ctl_table_header *head = grab_header(inode); 651f1ecf068SLucas De Marchi struct ctl_table *table = PROC_I(inode)->sysctl_entry; 652076ccb76SAl Viro __poll_t ret = DEFAULT_POLLMASK; 6534e474a00SLucas De Marchi unsigned long event; 6544e474a00SLucas De Marchi 6554e474a00SLucas De Marchi /* sysctl was unregistered */ 6564e474a00SLucas De Marchi if (IS_ERR(head)) 657a9a08845SLinus Torvalds return EPOLLERR | EPOLLHUP; 658f1ecf068SLucas De Marchi 659f1ecf068SLucas De Marchi if (!table->proc_handler) 660f1ecf068SLucas De Marchi goto out; 661f1ecf068SLucas De Marchi 662f1ecf068SLucas De Marchi if (!table->poll) 663f1ecf068SLucas De Marchi goto out; 664f1ecf068SLucas De Marchi 6654e474a00SLucas De Marchi event = (unsigned long)filp->private_data; 666f1ecf068SLucas De Marchi poll_wait(filp, &table->poll->wait, wait); 667f1ecf068SLucas De Marchi 668f1ecf068SLucas De Marchi if (event != atomic_read(&table->poll->event)) { 669f1ecf068SLucas De Marchi filp->private_data = proc_sys_poll_event(table->poll); 670a9a08845SLinus Torvalds ret = EPOLLIN | EPOLLRDNORM | EPOLLERR | EPOLLPRI; 671f1ecf068SLucas De Marchi } 672f1ecf068SLucas De Marchi 673f1ecf068SLucas De Marchi out: 6744e474a00SLucas De Marchi sysctl_head_finish(head); 6754e474a00SLucas De Marchi 676f1ecf068SLucas De Marchi return ret; 677f1ecf068SLucas De Marchi } 67877b14db5SEric W. Biederman 679f0c3b509SAl Viro static bool proc_sys_fill_cache(struct file *file, 680f0c3b509SAl Viro struct dir_context *ctx, 6819043476fSAl Viro struct ctl_table_header *head, 6829043476fSAl Viro struct ctl_table *table) 68377b14db5SEric W. Biederman { 684f0c3b509SAl Viro struct dentry *child, *dir = file->f_path.dentry; 68577b14db5SEric W. Biederman struct inode *inode; 68677b14db5SEric W. Biederman struct qstr qname; 68777b14db5SEric W. Biederman ino_t ino = 0; 68877b14db5SEric W. Biederman unsigned type = DT_UNKNOWN; 68977b14db5SEric W. Biederman 69077b14db5SEric W. Biederman qname.name = table->procname; 69177b14db5SEric W. Biederman qname.len = strlen(table->procname); 6928387ff25SLinus Torvalds qname.hash = full_name_hash(dir, qname.name, qname.len); 69377b14db5SEric W. Biederman 69477b14db5SEric W. Biederman child = d_lookup(dir, &qname); 69577b14db5SEric W. Biederman if (!child) { 69676aab3abSAl Viro DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 69776aab3abSAl Viro child = d_alloc_parallel(dir, &qname, &wq); 69876aab3abSAl Viro if (IS_ERR(child)) 69976aab3abSAl Viro return false; 70076aab3abSAl Viro if (d_in_lookup(child)) { 701888e2b03SAl Viro struct dentry *res; 7029043476fSAl Viro inode = proc_sys_make_inode(dir->d_sb, head, table); 703ea5751ccSIvan Delalande if (IS_ERR(inode)) { 70476aab3abSAl Viro d_lookup_done(child); 7059043476fSAl Viro dput(child); 706f0c3b509SAl Viro return false; 70776aab3abSAl Viro } 708fb045adbSNick Piggin d_set_d_op(child, &proc_sys_dentry_operations); 709888e2b03SAl Viro res = d_splice_alias(inode, child); 710888e2b03SAl Viro d_lookup_done(child); 711888e2b03SAl Viro if (unlikely(res)) { 712888e2b03SAl Viro if (IS_ERR(res)) { 713888e2b03SAl Viro dput(child); 714888e2b03SAl Viro return false; 715888e2b03SAl Viro } 716888e2b03SAl Viro dput(child); 717888e2b03SAl Viro child = res; 718888e2b03SAl Viro } 71977b14db5SEric W. Biederman } 72077b14db5SEric W. Biederman } 7212b0143b5SDavid Howells inode = d_inode(child); 72277b14db5SEric W. Biederman ino = inode->i_ino; 72377b14db5SEric W. Biederman type = inode->i_mode >> 12; 72477b14db5SEric W. Biederman dput(child); 725f0c3b509SAl Viro return dir_emit(ctx, qname.name, qname.len, ino, type); 7269043476fSAl Viro } 7279043476fSAl Viro 728f0c3b509SAl Viro static bool proc_sys_link_fill_cache(struct file *file, 729f0c3b509SAl Viro struct dir_context *ctx, 7300e47c99dSEric W. Biederman struct ctl_table_header *head, 7310e47c99dSEric W. Biederman struct ctl_table *table) 7320e47c99dSEric W. Biederman { 733f0c3b509SAl Viro bool ret = true; 734a0b0d1c3SDanilo Krummrich 7350e47c99dSEric W. Biederman head = sysctl_head_grab(head); 736a0b0d1c3SDanilo Krummrich if (IS_ERR(head)) 737a0b0d1c3SDanilo Krummrich return false; 7380e47c99dSEric W. Biederman 7390e47c99dSEric W. Biederman /* It is not an error if we can not follow the link ignore it */ 740835b94e0SDanilo Krummrich if (sysctl_follow_link(&head, &table)) 7410e47c99dSEric W. Biederman goto out; 7420e47c99dSEric W. Biederman 743f0c3b509SAl Viro ret = proc_sys_fill_cache(file, ctx, head, table); 7440e47c99dSEric W. Biederman out: 7450e47c99dSEric W. Biederman sysctl_head_finish(head); 7460e47c99dSEric W. Biederman return ret; 7470e47c99dSEric W. Biederman } 7480e47c99dSEric W. Biederman 749e5eea098SJoe Perches static int scan(struct ctl_table_header *head, struct ctl_table *table, 7509043476fSAl Viro unsigned long *pos, struct file *file, 751f0c3b509SAl Viro struct dir_context *ctx) 7529043476fSAl Viro { 753f0c3b509SAl Viro bool res; 7549043476fSAl Viro 755f0c3b509SAl Viro if ((*pos)++ < ctx->pos) 756f0c3b509SAl Viro return true; 7579043476fSAl Viro 7580e47c99dSEric W. Biederman if (unlikely(S_ISLNK(table->mode))) 759f0c3b509SAl Viro res = proc_sys_link_fill_cache(file, ctx, head, table); 7600e47c99dSEric W. Biederman else 761f0c3b509SAl Viro res = proc_sys_fill_cache(file, ctx, head, table); 7629043476fSAl Viro 763f0c3b509SAl Viro if (res) 764f0c3b509SAl Viro ctx->pos = *pos; 7656a75ce16SEric W. Biederman 7666a75ce16SEric W. Biederman return res; 76777b14db5SEric W. Biederman } 76877b14db5SEric W. Biederman 769f0c3b509SAl Viro static int proc_sys_readdir(struct file *file, struct dir_context *ctx) 77077b14db5SEric W. Biederman { 771f0c3b509SAl Viro struct ctl_table_header *head = grab_header(file_inode(file)); 7729043476fSAl Viro struct ctl_table_header *h = NULL; 7736a75ce16SEric W. Biederman struct ctl_table *entry; 7747ec66d06SEric W. Biederman struct ctl_dir *ctl_dir; 77577b14db5SEric W. Biederman unsigned long pos; 77677b14db5SEric W. Biederman 7779043476fSAl Viro if (IS_ERR(head)) 7789043476fSAl Viro return PTR_ERR(head); 7799043476fSAl Viro 7807ec66d06SEric W. Biederman ctl_dir = container_of(head, struct ctl_dir, header); 78177b14db5SEric W. Biederman 782f0c3b509SAl Viro if (!dir_emit_dots(file, ctx)) 78393362fa4SZhou Chengming goto out; 784f0c3b509SAl Viro 78577b14db5SEric W. Biederman pos = 2; 78677b14db5SEric W. Biederman 7877ec66d06SEric W. Biederman for (first_entry(ctl_dir, &h, &entry); h; next_entry(&h, &entry)) { 788f0c3b509SAl Viro if (!scan(h, entry, &pos, file, ctx)) { 7899043476fSAl Viro sysctl_head_finish(h); 7909043476fSAl Viro break; 79177b14db5SEric W. Biederman } 79277b14db5SEric W. Biederman } 79393362fa4SZhou Chengming out: 79477b14db5SEric W. Biederman sysctl_head_finish(head); 795f0c3b509SAl Viro return 0; 79677b14db5SEric W. Biederman } 79777b14db5SEric W. Biederman 798549c7297SChristian Brauner static int proc_sys_permission(struct user_namespace *mnt_userns, 799549c7297SChristian Brauner struct inode *inode, int mask) 80077b14db5SEric W. Biederman { 80177b14db5SEric W. Biederman /* 80277b14db5SEric W. Biederman * sysctl entries that are not writeable, 80377b14db5SEric W. Biederman * are _NOT_ writeable, capabilities or not. 80477b14db5SEric W. Biederman */ 805f696a365SMiklos Szeredi struct ctl_table_header *head; 806f696a365SMiklos Szeredi struct ctl_table *table; 80777b14db5SEric W. Biederman int error; 80877b14db5SEric W. Biederman 809f696a365SMiklos Szeredi /* Executable files are not allowed under /proc/sys/ */ 810f696a365SMiklos Szeredi if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) 811f696a365SMiklos Szeredi return -EACCES; 812f696a365SMiklos Szeredi 813f696a365SMiklos Szeredi head = grab_header(inode); 8149043476fSAl Viro if (IS_ERR(head)) 8159043476fSAl Viro return PTR_ERR(head); 81677b14db5SEric W. Biederman 817f696a365SMiklos Szeredi table = PROC_I(inode)->sysctl_entry; 8189043476fSAl Viro if (!table) /* global root - r-xr-xr-x */ 8199043476fSAl Viro error = mask & MAY_WRITE ? -EACCES : 0; 8209043476fSAl Viro else /* Use the permissions on the sysctl table entry */ 82173f7ef43SEric W. Biederman error = sysctl_perm(head, table, mask & ~MAY_NOT_BLOCK); 8229043476fSAl Viro 82377b14db5SEric W. Biederman sysctl_head_finish(head); 82477b14db5SEric W. Biederman return error; 82577b14db5SEric W. Biederman } 82677b14db5SEric W. Biederman 827549c7297SChristian Brauner static int proc_sys_setattr(struct user_namespace *mnt_userns, 828549c7297SChristian Brauner struct dentry *dentry, struct iattr *attr) 82977b14db5SEric W. Biederman { 8302b0143b5SDavid Howells struct inode *inode = d_inode(dentry); 83177b14db5SEric W. Biederman int error; 83277b14db5SEric W. Biederman 83377b14db5SEric W. Biederman if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) 83477b14db5SEric W. Biederman return -EPERM; 83577b14db5SEric W. Biederman 8362f221d6fSChristian Brauner error = setattr_prepare(&init_user_ns, dentry, attr); 8371025774cSChristoph Hellwig if (error) 83877b14db5SEric W. Biederman return error; 8391025774cSChristoph Hellwig 8402f221d6fSChristian Brauner setattr_copy(&init_user_ns, inode, attr); 8411025774cSChristoph Hellwig mark_inode_dirty(inode); 8421025774cSChristoph Hellwig return 0; 84377b14db5SEric W. Biederman } 84477b14db5SEric W. Biederman 845549c7297SChristian Brauner static int proc_sys_getattr(struct user_namespace *mnt_userns, 846549c7297SChristian Brauner const struct path *path, struct kstat *stat, 847a528d35eSDavid Howells u32 request_mask, unsigned int query_flags) 8489043476fSAl Viro { 849a528d35eSDavid Howells struct inode *inode = d_inode(path->dentry); 8509043476fSAl Viro struct ctl_table_header *head = grab_header(inode); 8519043476fSAl Viro struct ctl_table *table = PROC_I(inode)->sysctl_entry; 8529043476fSAl Viro 8539043476fSAl Viro if (IS_ERR(head)) 8549043476fSAl Viro return PTR_ERR(head); 8559043476fSAl Viro 8560d56a451SChristian Brauner generic_fillattr(&init_user_ns, inode, stat); 8579043476fSAl Viro if (table) 8589043476fSAl Viro stat->mode = (stat->mode & S_IFMT) | table->mode; 8599043476fSAl Viro 8609043476fSAl Viro sysctl_head_finish(head); 8619043476fSAl Viro return 0; 8629043476fSAl Viro } 8639043476fSAl Viro 86477b14db5SEric W. Biederman static const struct file_operations proc_sys_file_operations = { 865f1ecf068SLucas De Marchi .open = proc_sys_open, 866f1ecf068SLucas De Marchi .poll = proc_sys_poll, 8674bd6a735SMatthew Wilcox (Oracle) .read_iter = proc_sys_read, 8684bd6a735SMatthew Wilcox (Oracle) .write_iter = proc_sys_write, 8694bd6a735SMatthew Wilcox (Oracle) .splice_read = generic_file_splice_read, 8704bd6a735SMatthew Wilcox (Oracle) .splice_write = iter_file_splice_write, 8716038f373SArnd Bergmann .llseek = default_llseek, 8729043476fSAl Viro }; 8739043476fSAl Viro 8749043476fSAl Viro static const struct file_operations proc_sys_dir_file_operations = { 875887df078SPavel Emelyanov .read = generic_read_dir, 876f50752eaSAl Viro .iterate_shared = proc_sys_readdir, 8773222a3e5SChristoph Hellwig .llseek = generic_file_llseek, 87877b14db5SEric W. Biederman }; 87977b14db5SEric W. Biederman 88003a44825SJan Engelhardt static const struct inode_operations proc_sys_inode_operations = { 8819043476fSAl Viro .permission = proc_sys_permission, 8829043476fSAl Viro .setattr = proc_sys_setattr, 8839043476fSAl Viro .getattr = proc_sys_getattr, 8849043476fSAl Viro }; 8859043476fSAl Viro 8869043476fSAl Viro static const struct inode_operations proc_sys_dir_operations = { 88777b14db5SEric W. Biederman .lookup = proc_sys_lookup, 88877b14db5SEric W. Biederman .permission = proc_sys_permission, 88977b14db5SEric W. Biederman .setattr = proc_sys_setattr, 8909043476fSAl Viro .getattr = proc_sys_getattr, 89177b14db5SEric W. Biederman }; 89277b14db5SEric W. Biederman 8930b728e19SAl Viro static int proc_sys_revalidate(struct dentry *dentry, unsigned int flags) 89477b14db5SEric W. Biederman { 8950b728e19SAl Viro if (flags & LOOKUP_RCU) 89634286d66SNick Piggin return -ECHILD; 8972b0143b5SDavid Howells return !PROC_I(d_inode(dentry))->sysctl->unregistering; 8989043476fSAl Viro } 8999043476fSAl Viro 900fe15ce44SNick Piggin static int proc_sys_delete(const struct dentry *dentry) 9019043476fSAl Viro { 9022b0143b5SDavid Howells return !!PROC_I(d_inode(dentry))->sysctl->unregistering; 9039043476fSAl Viro } 9049043476fSAl Viro 9051f87f0b5SEric W. Biederman static int sysctl_is_seen(struct ctl_table_header *p) 9061f87f0b5SEric W. Biederman { 9071f87f0b5SEric W. Biederman struct ctl_table_set *set = p->set; 9081f87f0b5SEric W. Biederman int res; 9091f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 9101f87f0b5SEric W. Biederman if (p->unregistering) 9111f87f0b5SEric W. Biederman res = 0; 9121f87f0b5SEric W. Biederman else if (!set->is_seen) 9131f87f0b5SEric W. Biederman res = 1; 9141f87f0b5SEric W. Biederman else 9151f87f0b5SEric W. Biederman res = set->is_seen(set); 9161f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 9171f87f0b5SEric W. Biederman return res; 9181f87f0b5SEric W. Biederman } 9191f87f0b5SEric W. Biederman 9206fa67e70SAl Viro static int proc_sys_compare(const struct dentry *dentry, 921621e155aSNick Piggin unsigned int len, const char *str, const struct qstr *name) 9229043476fSAl Viro { 923dfef6dcdSAl Viro struct ctl_table_header *head; 924da53be12SLinus Torvalds struct inode *inode; 925da53be12SLinus Torvalds 92631e6b01fSNick Piggin /* Although proc doesn't have negative dentries, rcu-walk means 92731e6b01fSNick Piggin * that inode here can be NULL */ 928dfef6dcdSAl Viro /* AV: can it, indeed? */ 9292b0143b5SDavid Howells inode = d_inode_rcu(dentry); 93031e6b01fSNick Piggin if (!inode) 931dfef6dcdSAl Viro return 1; 932621e155aSNick Piggin if (name->len != len) 9339043476fSAl Viro return 1; 934621e155aSNick Piggin if (memcmp(name->name, str, len)) 9359043476fSAl Viro return 1; 936dfef6dcdSAl Viro head = rcu_dereference(PROC_I(inode)->sysctl); 937dfef6dcdSAl Viro return !head || !sysctl_is_seen(head); 93877b14db5SEric W. Biederman } 93977b14db5SEric W. Biederman 940d72f71ebSAl Viro static const struct dentry_operations proc_sys_dentry_operations = { 94177b14db5SEric W. Biederman .d_revalidate = proc_sys_revalidate, 9429043476fSAl Viro .d_delete = proc_sys_delete, 9439043476fSAl Viro .d_compare = proc_sys_compare, 94477b14db5SEric W. Biederman }; 94577b14db5SEric W. Biederman 9460e47c99dSEric W. Biederman static struct ctl_dir *find_subdir(struct ctl_dir *dir, 9477ec66d06SEric W. Biederman const char *name, int namelen) 9481f87f0b5SEric W. Biederman { 9497ec66d06SEric W. Biederman struct ctl_table_header *head; 9507ec66d06SEric W. Biederman struct ctl_table *entry; 9511f87f0b5SEric W. Biederman 9520e47c99dSEric W. Biederman entry = find_entry(&head, dir, name, namelen); 9537ec66d06SEric W. Biederman if (!entry) 9547ec66d06SEric W. Biederman return ERR_PTR(-ENOENT); 95551f72f4aSEric W. Biederman if (!S_ISDIR(entry->mode)) 9567ec66d06SEric W. Biederman return ERR_PTR(-ENOTDIR); 95751f72f4aSEric W. Biederman return container_of(head, struct ctl_dir, header); 9581f87f0b5SEric W. Biederman } 9591f87f0b5SEric W. Biederman 9607ec66d06SEric W. Biederman static struct ctl_dir *new_dir(struct ctl_table_set *set, 9617ec66d06SEric W. Biederman const char *name, int namelen) 9621f87f0b5SEric W. Biederman { 9637ec66d06SEric W. Biederman struct ctl_table *table; 9647ec66d06SEric W. Biederman struct ctl_dir *new; 965ac13ac6fSEric W. Biederman struct ctl_node *node; 9667ec66d06SEric W. Biederman char *new_name; 9671f87f0b5SEric W. Biederman 968ac13ac6fSEric W. Biederman new = kzalloc(sizeof(*new) + sizeof(struct ctl_node) + 969ac13ac6fSEric W. Biederman sizeof(struct ctl_table)*2 + namelen + 1, 970ac13ac6fSEric W. Biederman GFP_KERNEL); 9717ec66d06SEric W. Biederman if (!new) 9727ec66d06SEric W. Biederman return NULL; 9737ec66d06SEric W. Biederman 974ac13ac6fSEric W. Biederman node = (struct ctl_node *)(new + 1); 975ac13ac6fSEric W. Biederman table = (struct ctl_table *)(node + 1); 9767ec66d06SEric W. Biederman new_name = (char *)(table + 2); 9777ec66d06SEric W. Biederman memcpy(new_name, name, namelen); 9787ec66d06SEric W. Biederman new_name[namelen] = '\0'; 9797ec66d06SEric W. Biederman table[0].procname = new_name; 9807ec66d06SEric W. Biederman table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO; 981ac13ac6fSEric W. Biederman init_header(&new->header, set->dir.header.root, set, node, table); 9827ec66d06SEric W. Biederman 9837ec66d06SEric W. Biederman return new; 9841f87f0b5SEric W. Biederman } 9851f87f0b5SEric W. Biederman 98660f126d9SEric W. Biederman /** 98760f126d9SEric W. Biederman * get_subdir - find or create a subdir with the specified name. 98860f126d9SEric W. Biederman * @dir: Directory to create the subdirectory in 98960f126d9SEric W. Biederman * @name: The name of the subdirectory to find or create 99060f126d9SEric W. Biederman * @namelen: The length of name 99160f126d9SEric W. Biederman * 99260f126d9SEric W. Biederman * Takes a directory with an elevated reference count so we know that 99360f126d9SEric W. Biederman * if we drop the lock the directory will not go away. Upon success 99460f126d9SEric W. Biederman * the reference is moved from @dir to the returned subdirectory. 99560f126d9SEric W. Biederman * Upon error an error code is returned and the reference on @dir is 99660f126d9SEric W. Biederman * simply dropped. 99760f126d9SEric W. Biederman */ 9980e47c99dSEric W. Biederman static struct ctl_dir *get_subdir(struct ctl_dir *dir, 9990e47c99dSEric W. Biederman const char *name, int namelen) 10007ec66d06SEric W. Biederman { 10010e47c99dSEric W. Biederman struct ctl_table_set *set = dir->header.set; 10027ec66d06SEric W. Biederman struct ctl_dir *subdir, *new = NULL; 10030eb97f38SEric W. Biederman int err; 10047ec66d06SEric W. Biederman 10057ec66d06SEric W. Biederman spin_lock(&sysctl_lock); 10060e47c99dSEric W. Biederman subdir = find_subdir(dir, name, namelen); 10077ec66d06SEric W. Biederman if (!IS_ERR(subdir)) 10087ec66d06SEric W. Biederman goto found; 10097ec66d06SEric W. Biederman if (PTR_ERR(subdir) != -ENOENT) 10107ec66d06SEric W. Biederman goto failed; 10117ec66d06SEric W. Biederman 10127ec66d06SEric W. Biederman spin_unlock(&sysctl_lock); 10137ec66d06SEric W. Biederman new = new_dir(set, name, namelen); 10147ec66d06SEric W. Biederman spin_lock(&sysctl_lock); 10157ec66d06SEric W. Biederman subdir = ERR_PTR(-ENOMEM); 10167ec66d06SEric W. Biederman if (!new) 10177ec66d06SEric W. Biederman goto failed; 10187ec66d06SEric W. Biederman 101960f126d9SEric W. Biederman /* Was the subdir added while we dropped the lock? */ 10200e47c99dSEric W. Biederman subdir = find_subdir(dir, name, namelen); 10217ec66d06SEric W. Biederman if (!IS_ERR(subdir)) 10227ec66d06SEric W. Biederman goto found; 10237ec66d06SEric W. Biederman if (PTR_ERR(subdir) != -ENOENT) 10247ec66d06SEric W. Biederman goto failed; 10257ec66d06SEric W. Biederman 102660f126d9SEric W. Biederman /* Nope. Use the our freshly made directory entry. */ 10270eb97f38SEric W. Biederman err = insert_header(dir, &new->header); 10280eb97f38SEric W. Biederman subdir = ERR_PTR(err); 10290eb97f38SEric W. Biederman if (err) 10300e47c99dSEric W. Biederman goto failed; 10317ec66d06SEric W. Biederman subdir = new; 10327ec66d06SEric W. Biederman found: 10337ec66d06SEric W. Biederman subdir->header.nreg++; 10347ec66d06SEric W. Biederman failed: 1035a1c83681SViresh Kumar if (IS_ERR(subdir)) { 103687ebdc00SAndrew Morton pr_err("sysctl could not get directory: "); 10376980128fSEric W. Biederman sysctl_print_dir(dir); 1038153ee1c4SGeert Uytterhoeven pr_cont("%*.*s %ld\n", namelen, namelen, name, 1039153ee1c4SGeert Uytterhoeven PTR_ERR(subdir)); 10401f87f0b5SEric W. Biederman } 10417ec66d06SEric W. Biederman drop_sysctl_table(&dir->header); 10427ec66d06SEric W. Biederman if (new) 10437ec66d06SEric W. Biederman drop_sysctl_table(&new->header); 10447ec66d06SEric W. Biederman spin_unlock(&sysctl_lock); 10457ec66d06SEric W. Biederman return subdir; 10461f87f0b5SEric W. Biederman } 10471f87f0b5SEric W. Biederman 10480e47c99dSEric W. Biederman static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir) 10490e47c99dSEric W. Biederman { 10500e47c99dSEric W. Biederman struct ctl_dir *parent; 10510e47c99dSEric W. Biederman const char *procname; 10520e47c99dSEric W. Biederman if (!dir->header.parent) 10530e47c99dSEric W. Biederman return &set->dir; 10540e47c99dSEric W. Biederman parent = xlate_dir(set, dir->header.parent); 10550e47c99dSEric W. Biederman if (IS_ERR(parent)) 10560e47c99dSEric W. Biederman return parent; 10570e47c99dSEric W. Biederman procname = dir->header.ctl_table[0].procname; 10580e47c99dSEric W. Biederman return find_subdir(parent, procname, strlen(procname)); 10590e47c99dSEric W. Biederman } 10600e47c99dSEric W. Biederman 10610e47c99dSEric W. Biederman static int sysctl_follow_link(struct ctl_table_header **phead, 106213bcc6a2SEric W. Biederman struct ctl_table **pentry) 10630e47c99dSEric W. Biederman { 10640e47c99dSEric W. Biederman struct ctl_table_header *head; 10650e47c99dSEric W. Biederman struct ctl_table_root *root; 10660e47c99dSEric W. Biederman struct ctl_table_set *set; 10670e47c99dSEric W. Biederman struct ctl_table *entry; 10680e47c99dSEric W. Biederman struct ctl_dir *dir; 10690e47c99dSEric W. Biederman int ret; 10700e47c99dSEric W. Biederman 10710e47c99dSEric W. Biederman spin_lock(&sysctl_lock); 10720e47c99dSEric W. Biederman root = (*pentry)->data; 107313bcc6a2SEric W. Biederman set = lookup_header_set(root); 10740e47c99dSEric W. Biederman dir = xlate_dir(set, (*phead)->parent); 10750e47c99dSEric W. Biederman if (IS_ERR(dir)) 10760e47c99dSEric W. Biederman ret = PTR_ERR(dir); 10770e47c99dSEric W. Biederman else { 10780e47c99dSEric W. Biederman const char *procname = (*pentry)->procname; 10790e47c99dSEric W. Biederman head = NULL; 10800e47c99dSEric W. Biederman entry = find_entry(&head, dir, procname, strlen(procname)); 10810e47c99dSEric W. Biederman ret = -ENOENT; 10820e47c99dSEric W. Biederman if (entry && use_table(head)) { 10830e47c99dSEric W. Biederman unuse_table(*phead); 10840e47c99dSEric W. Biederman *phead = head; 10850e47c99dSEric W. Biederman *pentry = entry; 10860e47c99dSEric W. Biederman ret = 0; 10870e47c99dSEric W. Biederman } 10880e47c99dSEric W. Biederman } 10890e47c99dSEric W. Biederman 10900e47c99dSEric W. Biederman spin_unlock(&sysctl_lock); 10910e47c99dSEric W. Biederman return ret; 10920e47c99dSEric W. Biederman } 10930e47c99dSEric W. Biederman 10947c60c48fSEric W. Biederman static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...) 10957c60c48fSEric W. Biederman { 10967c60c48fSEric W. Biederman struct va_format vaf; 10977c60c48fSEric W. Biederman va_list args; 10987c60c48fSEric W. Biederman 10997c60c48fSEric W. Biederman va_start(args, fmt); 11007c60c48fSEric W. Biederman vaf.fmt = fmt; 11017c60c48fSEric W. Biederman vaf.va = &args; 11027c60c48fSEric W. Biederman 110387ebdc00SAndrew Morton pr_err("sysctl table check failed: %s/%s %pV\n", 11047c60c48fSEric W. Biederman path, table->procname, &vaf); 11057c60c48fSEric W. Biederman 11067c60c48fSEric W. Biederman va_end(args); 11077c60c48fSEric W. Biederman return -EINVAL; 11087c60c48fSEric W. Biederman } 11097c60c48fSEric W. Biederman 11104f2fec00SLuis R. Rodriguez static int sysctl_check_table_array(const char *path, struct ctl_table *table) 11114f2fec00SLuis R. Rodriguez { 11124f2fec00SLuis R. Rodriguez int err = 0; 11134f2fec00SLuis R. Rodriguez 111461d9b56aSLuis R. Rodriguez if ((table->proc_handler == proc_douintvec) || 111561d9b56aSLuis R. Rodriguez (table->proc_handler == proc_douintvec_minmax)) { 11164f2fec00SLuis R. Rodriguez if (table->maxlen != sizeof(unsigned int)) 111764a11f3dSWaiman Long err |= sysctl_err(path, table, "array not allowed"); 11184f2fec00SLuis R. Rodriguez } 11194f2fec00SLuis R. Rodriguez 1120cb944413SEric Dumazet if (table->proc_handler == proc_dou8vec_minmax) { 1121cb944413SEric Dumazet if (table->maxlen != sizeof(u8)) 1122cb944413SEric Dumazet err |= sysctl_err(path, table, "array not allowed"); 1123cb944413SEric Dumazet } 1124cb944413SEric Dumazet 11254f2fec00SLuis R. Rodriguez return err; 11264f2fec00SLuis R. Rodriguez } 11274f2fec00SLuis R. Rodriguez 11287c60c48fSEric W. Biederman static int sysctl_check_table(const char *path, struct ctl_table *table) 11297c60c48fSEric W. Biederman { 11307c60c48fSEric W. Biederman int err = 0; 11317c60c48fSEric W. Biederman for (; table->procname; table++) { 11327c60c48fSEric W. Biederman if (table->child) 113389c5b53bSLuis R. Rodriguez err |= sysctl_err(path, table, "Not a file"); 11347c60c48fSEric W. Biederman 11351f87f0b5SEric W. Biederman if ((table->proc_handler == proc_dostring) || 11361f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec) || 11371680a386SLiping Zhang (table->proc_handler == proc_douintvec) || 113861d9b56aSLuis R. Rodriguez (table->proc_handler == proc_douintvec_minmax) || 11391f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_minmax) || 1140cb944413SEric Dumazet (table->proc_handler == proc_dou8vec_minmax) || 11411f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_jiffies) || 11421f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_userhz_jiffies) || 11431f87f0b5SEric W. Biederman (table->proc_handler == proc_dointvec_ms_jiffies) || 11441f87f0b5SEric W. Biederman (table->proc_handler == proc_doulongvec_minmax) || 11451f87f0b5SEric W. Biederman (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) { 11461f87f0b5SEric W. Biederman if (!table->data) 114789c5b53bSLuis R. Rodriguez err |= sysctl_err(path, table, "No data"); 11481f87f0b5SEric W. Biederman if (!table->maxlen) 114989c5b53bSLuis R. Rodriguez err |= sysctl_err(path, table, "No maxlen"); 11504f2fec00SLuis R. Rodriguez else 11514f2fec00SLuis R. Rodriguez err |= sysctl_check_table_array(path, table); 11521f87f0b5SEric W. Biederman } 11531f87f0b5SEric W. Biederman if (!table->proc_handler) 115489c5b53bSLuis R. Rodriguez err |= sysctl_err(path, table, "No proc_handler"); 11557c60c48fSEric W. Biederman 11567c60c48fSEric W. Biederman if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode) 115789c5b53bSLuis R. Rodriguez err |= sysctl_err(path, table, "bogus .mode 0%o", 11587c60c48fSEric W. Biederman table->mode); 11591f87f0b5SEric W. Biederman } 11607c60c48fSEric W. Biederman return err; 11611f87f0b5SEric W. Biederman } 11621f87f0b5SEric W. Biederman 11630e47c99dSEric W. Biederman static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table *table, 11640e47c99dSEric W. Biederman struct ctl_table_root *link_root) 11650e47c99dSEric W. Biederman { 11660e47c99dSEric W. Biederman struct ctl_table *link_table, *entry, *link; 11670e47c99dSEric W. Biederman struct ctl_table_header *links; 1168ac13ac6fSEric W. Biederman struct ctl_node *node; 11690e47c99dSEric W. Biederman char *link_name; 11700e47c99dSEric W. Biederman int nr_entries, name_bytes; 11710e47c99dSEric W. Biederman 11720e47c99dSEric W. Biederman name_bytes = 0; 11730e47c99dSEric W. Biederman nr_entries = 0; 11740e47c99dSEric W. Biederman for (entry = table; entry->procname; entry++) { 11750e47c99dSEric W. Biederman nr_entries++; 11760e47c99dSEric W. Biederman name_bytes += strlen(entry->procname) + 1; 11770e47c99dSEric W. Biederman } 11780e47c99dSEric W. Biederman 11790e47c99dSEric W. Biederman links = kzalloc(sizeof(struct ctl_table_header) + 1180ac13ac6fSEric W. Biederman sizeof(struct ctl_node)*nr_entries + 11810e47c99dSEric W. Biederman sizeof(struct ctl_table)*(nr_entries + 1) + 11820e47c99dSEric W. Biederman name_bytes, 11830e47c99dSEric W. Biederman GFP_KERNEL); 11840e47c99dSEric W. Biederman 11850e47c99dSEric W. Biederman if (!links) 11860e47c99dSEric W. Biederman return NULL; 11870e47c99dSEric W. Biederman 1188ac13ac6fSEric W. Biederman node = (struct ctl_node *)(links + 1); 1189ac13ac6fSEric W. Biederman link_table = (struct ctl_table *)(node + nr_entries); 11900e47c99dSEric W. Biederman link_name = (char *)&link_table[nr_entries + 1]; 11910e47c99dSEric W. Biederman 11920e47c99dSEric W. Biederman for (link = link_table, entry = table; entry->procname; link++, entry++) { 11930e47c99dSEric W. Biederman int len = strlen(entry->procname) + 1; 11940e47c99dSEric W. Biederman memcpy(link_name, entry->procname, len); 11950e47c99dSEric W. Biederman link->procname = link_name; 11960e47c99dSEric W. Biederman link->mode = S_IFLNK|S_IRWXUGO; 11970e47c99dSEric W. Biederman link->data = link_root; 11980e47c99dSEric W. Biederman link_name += len; 11990e47c99dSEric W. Biederman } 1200ac13ac6fSEric W. Biederman init_header(links, dir->header.root, dir->header.set, node, link_table); 12010e47c99dSEric W. Biederman links->nreg = nr_entries; 12020e47c99dSEric W. Biederman 12030e47c99dSEric W. Biederman return links; 12040e47c99dSEric W. Biederman } 12050e47c99dSEric W. Biederman 12060e47c99dSEric W. Biederman static bool get_links(struct ctl_dir *dir, 12070e47c99dSEric W. Biederman struct ctl_table *table, struct ctl_table_root *link_root) 12080e47c99dSEric W. Biederman { 12090e47c99dSEric W. Biederman struct ctl_table_header *head; 12100e47c99dSEric W. Biederman struct ctl_table *entry, *link; 12110e47c99dSEric W. Biederman 12120e47c99dSEric W. Biederman /* Are there links available for every entry in table? */ 12130e47c99dSEric W. Biederman for (entry = table; entry->procname; entry++) { 12140e47c99dSEric W. Biederman const char *procname = entry->procname; 12150e47c99dSEric W. Biederman link = find_entry(&head, dir, procname, strlen(procname)); 12160e47c99dSEric W. Biederman if (!link) 12170e47c99dSEric W. Biederman return false; 12180e47c99dSEric W. Biederman if (S_ISDIR(link->mode) && S_ISDIR(entry->mode)) 12190e47c99dSEric W. Biederman continue; 12200e47c99dSEric W. Biederman if (S_ISLNK(link->mode) && (link->data == link_root)) 12210e47c99dSEric W. Biederman continue; 12220e47c99dSEric W. Biederman return false; 12230e47c99dSEric W. Biederman } 12240e47c99dSEric W. Biederman 12250e47c99dSEric W. Biederman /* The checks passed. Increase the registration count on the links */ 12260e47c99dSEric W. Biederman for (entry = table; entry->procname; entry++) { 12270e47c99dSEric W. Biederman const char *procname = entry->procname; 12280e47c99dSEric W. Biederman link = find_entry(&head, dir, procname, strlen(procname)); 12290e47c99dSEric W. Biederman head->nreg++; 12300e47c99dSEric W. Biederman } 12310e47c99dSEric W. Biederman return true; 12320e47c99dSEric W. Biederman } 12330e47c99dSEric W. Biederman 12340e47c99dSEric W. Biederman static int insert_links(struct ctl_table_header *head) 12350e47c99dSEric W. Biederman { 12360e47c99dSEric W. Biederman struct ctl_table_set *root_set = &sysctl_table_root.default_set; 12370e47c99dSEric W. Biederman struct ctl_dir *core_parent = NULL; 12380e47c99dSEric W. Biederman struct ctl_table_header *links; 12390e47c99dSEric W. Biederman int err; 12400e47c99dSEric W. Biederman 12410e47c99dSEric W. Biederman if (head->set == root_set) 12420e47c99dSEric W. Biederman return 0; 12430e47c99dSEric W. Biederman 12440e47c99dSEric W. Biederman core_parent = xlate_dir(root_set, head->parent); 12450e47c99dSEric W. Biederman if (IS_ERR(core_parent)) 12460e47c99dSEric W. Biederman return 0; 12470e47c99dSEric W. Biederman 12480e47c99dSEric W. Biederman if (get_links(core_parent, head->ctl_table, head->root)) 12490e47c99dSEric W. Biederman return 0; 12500e47c99dSEric W. Biederman 12510e47c99dSEric W. Biederman core_parent->header.nreg++; 12520e47c99dSEric W. Biederman spin_unlock(&sysctl_lock); 12530e47c99dSEric W. Biederman 12540e47c99dSEric W. Biederman links = new_links(core_parent, head->ctl_table, head->root); 12550e47c99dSEric W. Biederman 12560e47c99dSEric W. Biederman spin_lock(&sysctl_lock); 12570e47c99dSEric W. Biederman err = -ENOMEM; 12580e47c99dSEric W. Biederman if (!links) 12590e47c99dSEric W. Biederman goto out; 12600e47c99dSEric W. Biederman 12610e47c99dSEric W. Biederman err = 0; 12620e47c99dSEric W. Biederman if (get_links(core_parent, head->ctl_table, head->root)) { 12630e47c99dSEric W. Biederman kfree(links); 12640e47c99dSEric W. Biederman goto out; 12650e47c99dSEric W. Biederman } 12660e47c99dSEric W. Biederman 12670e47c99dSEric W. Biederman err = insert_header(core_parent, links); 12680e47c99dSEric W. Biederman if (err) 12690e47c99dSEric W. Biederman kfree(links); 12700e47c99dSEric W. Biederman out: 12710e47c99dSEric W. Biederman drop_sysctl_table(&core_parent->header); 12720e47c99dSEric W. Biederman return err; 12730e47c99dSEric W. Biederman } 12740e47c99dSEric W. Biederman 12751f87f0b5SEric W. Biederman /** 1276f728019bSEric W. Biederman * __register_sysctl_table - register a leaf sysctl table 127760a47a2eSEric W. Biederman * @set: Sysctl tree to register on 12781f87f0b5SEric W. Biederman * @path: The path to the directory the sysctl table is in. 12791f87f0b5SEric W. Biederman * @table: the top-level table structure 12801f87f0b5SEric W. Biederman * 12811f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 12821f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 12831f87f0b5SEric W. Biederman * 12841f87f0b5SEric W. Biederman * The members of the &struct ctl_table structure are used as follows: 12851f87f0b5SEric W. Biederman * 12861f87f0b5SEric W. Biederman * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not 12871f87f0b5SEric W. Biederman * enter a sysctl file 12881f87f0b5SEric W. Biederman * 12891f87f0b5SEric W. Biederman * data - a pointer to data for use by proc_handler 12901f87f0b5SEric W. Biederman * 12911f87f0b5SEric W. Biederman * maxlen - the maximum size in bytes of the data 12921f87f0b5SEric W. Biederman * 1293f728019bSEric W. Biederman * mode - the file permissions for the /proc/sys file 12941f87f0b5SEric W. Biederman * 1295f728019bSEric W. Biederman * child - must be %NULL. 12961f87f0b5SEric W. Biederman * 12971f87f0b5SEric W. Biederman * proc_handler - the text handler routine (described below) 12981f87f0b5SEric W. Biederman * 12991f87f0b5SEric W. Biederman * extra1, extra2 - extra pointers usable by the proc handler routines 13001f87f0b5SEric W. Biederman * 13011f87f0b5SEric W. Biederman * Leaf nodes in the sysctl tree will be represented by a single file 13021f87f0b5SEric W. Biederman * under /proc; non-leaf nodes will be represented by directories. 13031f87f0b5SEric W. Biederman * 1304f728019bSEric W. Biederman * There must be a proc_handler routine for any terminal nodes. 1305f728019bSEric W. Biederman * Several default handlers are available to cover common cases - 13061f87f0b5SEric W. Biederman * 13071f87f0b5SEric W. Biederman * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), 13081f87f0b5SEric W. Biederman * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 13091f87f0b5SEric W. Biederman * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() 13101f87f0b5SEric W. Biederman * 13111f87f0b5SEric W. Biederman * It is the handler's job to read the input buffer from user memory 13121f87f0b5SEric W. Biederman * and process it. The handler should return 0 on success. 13131f87f0b5SEric W. Biederman * 13141f87f0b5SEric W. Biederman * This routine returns %NULL on a failure to register, and a pointer 13151f87f0b5SEric W. Biederman * to the table header on success. 13161f87f0b5SEric W. Biederman */ 13176e9d5164SEric W. Biederman struct ctl_table_header *__register_sysctl_table( 131860a47a2eSEric W. Biederman struct ctl_table_set *set, 13196e9d5164SEric W. Biederman const char *path, struct ctl_table *table) 13201f87f0b5SEric W. Biederman { 132160a47a2eSEric W. Biederman struct ctl_table_root *root = set->dir.header.root; 13221f87f0b5SEric W. Biederman struct ctl_table_header *header; 13236e9d5164SEric W. Biederman const char *name, *nextname; 13247ec66d06SEric W. Biederman struct ctl_dir *dir; 1325ac13ac6fSEric W. Biederman struct ctl_table *entry; 1326ac13ac6fSEric W. Biederman struct ctl_node *node; 1327ac13ac6fSEric W. Biederman int nr_entries = 0; 13281f87f0b5SEric W. Biederman 1329ac13ac6fSEric W. Biederman for (entry = table; entry->procname; entry++) 1330ac13ac6fSEric W. Biederman nr_entries++; 1331ac13ac6fSEric W. Biederman 1332ac13ac6fSEric W. Biederman header = kzalloc(sizeof(struct ctl_table_header) + 1333ac13ac6fSEric W. Biederman sizeof(struct ctl_node)*nr_entries, GFP_KERNEL); 13341f87f0b5SEric W. Biederman if (!header) 13351f87f0b5SEric W. Biederman return NULL; 13361f87f0b5SEric W. Biederman 1337ac13ac6fSEric W. Biederman node = (struct ctl_node *)(header + 1); 1338ac13ac6fSEric W. Biederman init_header(header, root, set, node, table); 13397c60c48fSEric W. Biederman if (sysctl_check_table(path, table)) 13407c60c48fSEric W. Biederman goto fail; 13418d6ecfccSEric W. Biederman 13421f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 13430e47c99dSEric W. Biederman dir = &set->dir; 134460f126d9SEric W. Biederman /* Reference moved down the diretory tree get_subdir */ 13457ec66d06SEric W. Biederman dir->header.nreg++; 13467ec66d06SEric W. Biederman spin_unlock(&sysctl_lock); 13477ec66d06SEric W. Biederman 13487ec66d06SEric W. Biederman /* Find the directory for the ctl_table */ 13497ec66d06SEric W. Biederman for (name = path; name; name = nextname) { 13507ec66d06SEric W. Biederman int namelen; 13517ec66d06SEric W. Biederman nextname = strchr(name, '/'); 13527ec66d06SEric W. Biederman if (nextname) { 13537ec66d06SEric W. Biederman namelen = nextname - name; 13547ec66d06SEric W. Biederman nextname++; 13557ec66d06SEric W. Biederman } else { 13567ec66d06SEric W. Biederman namelen = strlen(name); 13577ec66d06SEric W. Biederman } 13587ec66d06SEric W. Biederman if (namelen == 0) 13591f87f0b5SEric W. Biederman continue; 13607ec66d06SEric W. Biederman 13610e47c99dSEric W. Biederman dir = get_subdir(dir, name, namelen); 13627ec66d06SEric W. Biederman if (IS_ERR(dir)) 13637ec66d06SEric W. Biederman goto fail; 13641f87f0b5SEric W. Biederman } 13650e47c99dSEric W. Biederman 13667ec66d06SEric W. Biederman spin_lock(&sysctl_lock); 13670e47c99dSEric W. Biederman if (insert_header(dir, header)) 13680e47c99dSEric W. Biederman goto fail_put_dir_locked; 13690e47c99dSEric W. Biederman 13707ec66d06SEric W. Biederman drop_sysctl_table(&dir->header); 13711f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 13721f87f0b5SEric W. Biederman 13731f87f0b5SEric W. Biederman return header; 13740e47c99dSEric W. Biederman 13757ec66d06SEric W. Biederman fail_put_dir_locked: 13767ec66d06SEric W. Biederman drop_sysctl_table(&dir->header); 13777c60c48fSEric W. Biederman spin_unlock(&sysctl_lock); 13787c60c48fSEric W. Biederman fail: 13797c60c48fSEric W. Biederman kfree(header); 13807c60c48fSEric W. Biederman dump_stack(); 13817c60c48fSEric W. Biederman return NULL; 13821f87f0b5SEric W. Biederman } 13831f87f0b5SEric W. Biederman 1384fea478d4SEric W. Biederman /** 1385fea478d4SEric W. Biederman * register_sysctl - register a sysctl table 1386fea478d4SEric W. Biederman * @path: The path to the directory the sysctl table is in. 1387fea478d4SEric W. Biederman * @table: the table structure 1388fea478d4SEric W. Biederman * 1389fea478d4SEric W. Biederman * Register a sysctl table. @table should be a filled in ctl_table 1390fea478d4SEric W. Biederman * array. A completely 0 filled entry terminates the table. 1391fea478d4SEric W. Biederman * 1392fea478d4SEric W. Biederman * See __register_sysctl_table for more details. 1393fea478d4SEric W. Biederman */ 1394fea478d4SEric W. Biederman struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) 1395fea478d4SEric W. Biederman { 1396fea478d4SEric W. Biederman return __register_sysctl_table(&sysctl_table_root.default_set, 1397fea478d4SEric W. Biederman path, table); 1398fea478d4SEric W. Biederman } 1399fea478d4SEric W. Biederman EXPORT_SYMBOL(register_sysctl); 1400fea478d4SEric W. Biederman 14013ddd9a80SXiaoming Ni /** 14023ddd9a80SXiaoming Ni * __register_sysctl_init() - register sysctl table to path 14033ddd9a80SXiaoming Ni * @path: path name for sysctl base 14043ddd9a80SXiaoming Ni * @table: This is the sysctl table that needs to be registered to the path 14053ddd9a80SXiaoming Ni * @table_name: The name of sysctl table, only used for log printing when 14063ddd9a80SXiaoming Ni * registration fails 14073ddd9a80SXiaoming Ni * 14083ddd9a80SXiaoming Ni * The sysctl interface is used by userspace to query or modify at runtime 14093ddd9a80SXiaoming Ni * a predefined value set on a variable. These variables however have default 14103ddd9a80SXiaoming Ni * values pre-set. Code which depends on these variables will always work even 14113ddd9a80SXiaoming Ni * if register_sysctl() fails. If register_sysctl() fails you'd just loose the 14123ddd9a80SXiaoming Ni * ability to query or modify the sysctls dynamically at run time. Chances of 14133ddd9a80SXiaoming Ni * register_sysctl() failing on init are extremely low, and so for both reasons 14143ddd9a80SXiaoming Ni * this function does not return any error as it is used by initialization code. 14153ddd9a80SXiaoming Ni * 14163ddd9a80SXiaoming Ni * Context: Can only be called after your respective sysctl base path has been 14173ddd9a80SXiaoming Ni * registered. So for instance, most base directories are registered early on 14183ddd9a80SXiaoming Ni * init before init levels are processed through proc_sys_init() and 14193ddd9a80SXiaoming Ni * sysctl_init(). 14203ddd9a80SXiaoming Ni */ 14213ddd9a80SXiaoming Ni void __init __register_sysctl_init(const char *path, struct ctl_table *table, 14223ddd9a80SXiaoming Ni const char *table_name) 14233ddd9a80SXiaoming Ni { 14243ddd9a80SXiaoming Ni struct ctl_table_header *hdr = register_sysctl(path, table); 14253ddd9a80SXiaoming Ni 14263ddd9a80SXiaoming Ni if (unlikely(!hdr)) { 14273ddd9a80SXiaoming Ni pr_err("failed when register_sysctl %s to %s\n", table_name, path); 14283ddd9a80SXiaoming Ni return; 14293ddd9a80SXiaoming Ni } 14303ddd9a80SXiaoming Ni kmemleak_not_leak(hdr); 14313ddd9a80SXiaoming Ni } 14323ddd9a80SXiaoming Ni 14336e9d5164SEric W. Biederman static char *append_path(const char *path, char *pos, const char *name) 14346e9d5164SEric W. Biederman { 14356e9d5164SEric W. Biederman int namelen; 14366e9d5164SEric W. Biederman namelen = strlen(name); 14376e9d5164SEric W. Biederman if (((pos - path) + namelen + 2) >= PATH_MAX) 14386e9d5164SEric W. Biederman return NULL; 14396e9d5164SEric W. Biederman memcpy(pos, name, namelen); 14406e9d5164SEric W. Biederman pos[namelen] = '/'; 14416e9d5164SEric W. Biederman pos[namelen + 1] = '\0'; 14426e9d5164SEric W. Biederman pos += namelen + 1; 14436e9d5164SEric W. Biederman return pos; 14446e9d5164SEric W. Biederman } 14456e9d5164SEric W. Biederman 1446f728019bSEric W. Biederman static int count_subheaders(struct ctl_table *table) 1447f728019bSEric W. Biederman { 1448f728019bSEric W. Biederman int has_files = 0; 1449f728019bSEric W. Biederman int nr_subheaders = 0; 1450f728019bSEric W. Biederman struct ctl_table *entry; 1451f728019bSEric W. Biederman 1452f728019bSEric W. Biederman /* special case: no directory and empty directory */ 1453f728019bSEric W. Biederman if (!table || !table->procname) 1454f728019bSEric W. Biederman return 1; 1455f728019bSEric W. Biederman 1456f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1457f728019bSEric W. Biederman if (entry->child) 1458f728019bSEric W. Biederman nr_subheaders += count_subheaders(entry->child); 1459f728019bSEric W. Biederman else 1460f728019bSEric W. Biederman has_files = 1; 1461f728019bSEric W. Biederman } 1462f728019bSEric W. Biederman return nr_subheaders + has_files; 1463f728019bSEric W. Biederman } 1464f728019bSEric W. Biederman 1465f728019bSEric W. Biederman static int register_leaf_sysctl_tables(const char *path, char *pos, 146660a47a2eSEric W. Biederman struct ctl_table_header ***subheader, struct ctl_table_set *set, 1467f728019bSEric W. Biederman struct ctl_table *table) 1468f728019bSEric W. Biederman { 1469f728019bSEric W. Biederman struct ctl_table *ctl_table_arg = NULL; 1470f728019bSEric W. Biederman struct ctl_table *entry, *files; 1471f728019bSEric W. Biederman int nr_files = 0; 1472f728019bSEric W. Biederman int nr_dirs = 0; 1473f728019bSEric W. Biederman int err = -ENOMEM; 1474f728019bSEric W. Biederman 1475f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1476f728019bSEric W. Biederman if (entry->child) 1477f728019bSEric W. Biederman nr_dirs++; 1478f728019bSEric W. Biederman else 1479f728019bSEric W. Biederman nr_files++; 1480f728019bSEric W. Biederman } 1481f728019bSEric W. Biederman 1482f728019bSEric W. Biederman files = table; 1483f728019bSEric W. Biederman /* If there are mixed files and directories we need a new table */ 1484f728019bSEric W. Biederman if (nr_dirs && nr_files) { 1485f728019bSEric W. Biederman struct ctl_table *new; 14866396bb22SKees Cook files = kcalloc(nr_files + 1, sizeof(struct ctl_table), 1487f728019bSEric W. Biederman GFP_KERNEL); 1488f728019bSEric W. Biederman if (!files) 1489f728019bSEric W. Biederman goto out; 1490f728019bSEric W. Biederman 1491f728019bSEric W. Biederman ctl_table_arg = files; 1492f728019bSEric W. Biederman for (new = files, entry = table; entry->procname; entry++) { 1493f728019bSEric W. Biederman if (entry->child) 1494f728019bSEric W. Biederman continue; 1495f728019bSEric W. Biederman *new = *entry; 1496f728019bSEric W. Biederman new++; 1497f728019bSEric W. Biederman } 1498f728019bSEric W. Biederman } 1499f728019bSEric W. Biederman 1500f728019bSEric W. Biederman /* Register everything except a directory full of subdirectories */ 1501f728019bSEric W. Biederman if (nr_files || !nr_dirs) { 1502f728019bSEric W. Biederman struct ctl_table_header *header; 150360a47a2eSEric W. Biederman header = __register_sysctl_table(set, path, files); 1504f728019bSEric W. Biederman if (!header) { 1505f728019bSEric W. Biederman kfree(ctl_table_arg); 1506f728019bSEric W. Biederman goto out; 1507f728019bSEric W. Biederman } 1508f728019bSEric W. Biederman 1509f728019bSEric W. Biederman /* Remember if we need to free the file table */ 1510f728019bSEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1511f728019bSEric W. Biederman **subheader = header; 1512f728019bSEric W. Biederman (*subheader)++; 1513f728019bSEric W. Biederman } 1514f728019bSEric W. Biederman 1515f728019bSEric W. Biederman /* Recurse into the subdirectories. */ 1516f728019bSEric W. Biederman for (entry = table; entry->procname; entry++) { 1517f728019bSEric W. Biederman char *child_pos; 1518f728019bSEric W. Biederman 1519f728019bSEric W. Biederman if (!entry->child) 1520f728019bSEric W. Biederman continue; 1521f728019bSEric W. Biederman 1522f728019bSEric W. Biederman err = -ENAMETOOLONG; 1523f728019bSEric W. Biederman child_pos = append_path(path, pos, entry->procname); 1524f728019bSEric W. Biederman if (!child_pos) 1525f728019bSEric W. Biederman goto out; 1526f728019bSEric W. Biederman 1527f728019bSEric W. Biederman err = register_leaf_sysctl_tables(path, child_pos, subheader, 152860a47a2eSEric W. Biederman set, entry->child); 1529f728019bSEric W. Biederman pos[0] = '\0'; 1530f728019bSEric W. Biederman if (err) 1531f728019bSEric W. Biederman goto out; 1532f728019bSEric W. Biederman } 1533f728019bSEric W. Biederman err = 0; 1534f728019bSEric W. Biederman out: 1535f728019bSEric W. Biederman /* On failure our caller will unregister all registered subheaders */ 1536f728019bSEric W. Biederman return err; 1537f728019bSEric W. Biederman } 1538f728019bSEric W. Biederman 15396e9d5164SEric W. Biederman /** 15406e9d5164SEric W. Biederman * __register_sysctl_paths - register a sysctl table hierarchy 154160a47a2eSEric W. Biederman * @set: Sysctl tree to register on 15426e9d5164SEric W. Biederman * @path: The path to the directory the sysctl table is in. 15436e9d5164SEric W. Biederman * @table: the top-level table structure 15446e9d5164SEric W. Biederman * 15456e9d5164SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 15466e9d5164SEric W. Biederman * array. A completely 0 filled entry terminates the table. 15476e9d5164SEric W. Biederman * 15486e9d5164SEric W. Biederman * See __register_sysctl_table for more details. 15496e9d5164SEric W. Biederman */ 15506e9d5164SEric W. Biederman struct ctl_table_header *__register_sysctl_paths( 155160a47a2eSEric W. Biederman struct ctl_table_set *set, 15526e9d5164SEric W. Biederman const struct ctl_path *path, struct ctl_table *table) 15536e9d5164SEric W. Biederman { 1554ec6a5266SEric W. Biederman struct ctl_table *ctl_table_arg = table; 1555f728019bSEric W. Biederman int nr_subheaders = count_subheaders(table); 1556f728019bSEric W. Biederman struct ctl_table_header *header = NULL, **subheaders, **subheader; 15576e9d5164SEric W. Biederman const struct ctl_path *component; 15586e9d5164SEric W. Biederman char *new_path, *pos; 15596e9d5164SEric W. Biederman 15606e9d5164SEric W. Biederman pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); 15616e9d5164SEric W. Biederman if (!new_path) 15626e9d5164SEric W. Biederman return NULL; 15636e9d5164SEric W. Biederman 15646e9d5164SEric W. Biederman pos[0] = '\0'; 15656e9d5164SEric W. Biederman for (component = path; component->procname; component++) { 15666e9d5164SEric W. Biederman pos = append_path(new_path, pos, component->procname); 15676e9d5164SEric W. Biederman if (!pos) 15686e9d5164SEric W. Biederman goto out; 15696e9d5164SEric W. Biederman } 1570ec6a5266SEric W. Biederman while (table->procname && table->child && !table[1].procname) { 1571ec6a5266SEric W. Biederman pos = append_path(new_path, pos, table->procname); 1572ec6a5266SEric W. Biederman if (!pos) 1573ec6a5266SEric W. Biederman goto out; 1574ec6a5266SEric W. Biederman table = table->child; 1575ec6a5266SEric W. Biederman } 1576f728019bSEric W. Biederman if (nr_subheaders == 1) { 157760a47a2eSEric W. Biederman header = __register_sysctl_table(set, new_path, table); 1578ec6a5266SEric W. Biederman if (header) 1579ec6a5266SEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1580f728019bSEric W. Biederman } else { 1581f728019bSEric W. Biederman header = kzalloc(sizeof(*header) + 1582f728019bSEric W. Biederman sizeof(*subheaders)*nr_subheaders, GFP_KERNEL); 1583f728019bSEric W. Biederman if (!header) 1584f728019bSEric W. Biederman goto out; 1585f728019bSEric W. Biederman 1586f728019bSEric W. Biederman subheaders = (struct ctl_table_header **) (header + 1); 1587f728019bSEric W. Biederman subheader = subheaders; 1588f728019bSEric W. Biederman header->ctl_table_arg = ctl_table_arg; 1589f728019bSEric W. Biederman 1590f728019bSEric W. Biederman if (register_leaf_sysctl_tables(new_path, pos, &subheader, 159160a47a2eSEric W. Biederman set, table)) 1592f728019bSEric W. Biederman goto err_register_leaves; 1593f728019bSEric W. Biederman } 1594f728019bSEric W. Biederman 15956e9d5164SEric W. Biederman out: 15966e9d5164SEric W. Biederman kfree(new_path); 15976e9d5164SEric W. Biederman return header; 1598f728019bSEric W. Biederman 1599f728019bSEric W. Biederman err_register_leaves: 1600f728019bSEric W. Biederman while (subheader > subheaders) { 1601f728019bSEric W. Biederman struct ctl_table_header *subh = *(--subheader); 1602f728019bSEric W. Biederman struct ctl_table *table = subh->ctl_table_arg; 1603f728019bSEric W. Biederman unregister_sysctl_table(subh); 1604f728019bSEric W. Biederman kfree(table); 1605f728019bSEric W. Biederman } 1606f728019bSEric W. Biederman kfree(header); 1607f728019bSEric W. Biederman header = NULL; 1608f728019bSEric W. Biederman goto out; 16096e9d5164SEric W. Biederman } 16106e9d5164SEric W. Biederman 16111f87f0b5SEric W. Biederman /** 16125b31a7dfSzhouchuangao * register_sysctl_paths - register a sysctl table hierarchy 16131f87f0b5SEric W. Biederman * @path: The path to the directory the sysctl table is in. 16141f87f0b5SEric W. Biederman * @table: the top-level table structure 16151f87f0b5SEric W. Biederman * 16161f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 16171f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 16181f87f0b5SEric W. Biederman * 16191f87f0b5SEric W. Biederman * See __register_sysctl_paths for more details. 16201f87f0b5SEric W. Biederman */ 16211f87f0b5SEric W. Biederman struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, 16221f87f0b5SEric W. Biederman struct ctl_table *table) 16231f87f0b5SEric W. Biederman { 162460a47a2eSEric W. Biederman return __register_sysctl_paths(&sysctl_table_root.default_set, 16251f87f0b5SEric W. Biederman path, table); 16261f87f0b5SEric W. Biederman } 16271f87f0b5SEric W. Biederman EXPORT_SYMBOL(register_sysctl_paths); 16281f87f0b5SEric W. Biederman 16291f87f0b5SEric W. Biederman /** 16301f87f0b5SEric W. Biederman * register_sysctl_table - register a sysctl table hierarchy 16311f87f0b5SEric W. Biederman * @table: the top-level table structure 16321f87f0b5SEric W. Biederman * 16331f87f0b5SEric W. Biederman * Register a sysctl table hierarchy. @table should be a filled in ctl_table 16341f87f0b5SEric W. Biederman * array. A completely 0 filled entry terminates the table. 16351f87f0b5SEric W. Biederman * 16361f87f0b5SEric W. Biederman * See register_sysctl_paths for more details. 16371f87f0b5SEric W. Biederman */ 16381f87f0b5SEric W. Biederman struct ctl_table_header *register_sysctl_table(struct ctl_table *table) 16391f87f0b5SEric W. Biederman { 16401f87f0b5SEric W. Biederman static const struct ctl_path null_path[] = { {} }; 16411f87f0b5SEric W. Biederman 16421f87f0b5SEric W. Biederman return register_sysctl_paths(null_path, table); 16431f87f0b5SEric W. Biederman } 16441f87f0b5SEric W. Biederman EXPORT_SYMBOL(register_sysctl_table); 16451f87f0b5SEric W. Biederman 16460e47c99dSEric W. Biederman static void put_links(struct ctl_table_header *header) 16470e47c99dSEric W. Biederman { 16480e47c99dSEric W. Biederman struct ctl_table_set *root_set = &sysctl_table_root.default_set; 16490e47c99dSEric W. Biederman struct ctl_table_root *root = header->root; 16500e47c99dSEric W. Biederman struct ctl_dir *parent = header->parent; 16510e47c99dSEric W. Biederman struct ctl_dir *core_parent; 16520e47c99dSEric W. Biederman struct ctl_table *entry; 16530e47c99dSEric W. Biederman 16540e47c99dSEric W. Biederman if (header->set == root_set) 16550e47c99dSEric W. Biederman return; 16560e47c99dSEric W. Biederman 16570e47c99dSEric W. Biederman core_parent = xlate_dir(root_set, parent); 16580e47c99dSEric W. Biederman if (IS_ERR(core_parent)) 16590e47c99dSEric W. Biederman return; 16600e47c99dSEric W. Biederman 16610e47c99dSEric W. Biederman for (entry = header->ctl_table; entry->procname; entry++) { 16620e47c99dSEric W. Biederman struct ctl_table_header *link_head; 16630e47c99dSEric W. Biederman struct ctl_table *link; 16640e47c99dSEric W. Biederman const char *name = entry->procname; 16650e47c99dSEric W. Biederman 16660e47c99dSEric W. Biederman link = find_entry(&link_head, core_parent, name, strlen(name)); 16670e47c99dSEric W. Biederman if (link && 16680e47c99dSEric W. Biederman ((S_ISDIR(link->mode) && S_ISDIR(entry->mode)) || 16690e47c99dSEric W. Biederman (S_ISLNK(link->mode) && (link->data == root)))) { 16700e47c99dSEric W. Biederman drop_sysctl_table(link_head); 16710e47c99dSEric W. Biederman } 16720e47c99dSEric W. Biederman else { 167387ebdc00SAndrew Morton pr_err("sysctl link missing during unregister: "); 16740e47c99dSEric W. Biederman sysctl_print_dir(parent); 1675153ee1c4SGeert Uytterhoeven pr_cont("%s\n", name); 16760e47c99dSEric W. Biederman } 16770e47c99dSEric W. Biederman } 16780e47c99dSEric W. Biederman } 16790e47c99dSEric W. Biederman 1680938aaa4fSEric W. Biederman static void drop_sysctl_table(struct ctl_table_header *header) 1681938aaa4fSEric W. Biederman { 16827ec66d06SEric W. Biederman struct ctl_dir *parent = header->parent; 16837ec66d06SEric W. Biederman 1684938aaa4fSEric W. Biederman if (--header->nreg) 1685938aaa4fSEric W. Biederman return; 1686938aaa4fSEric W. Biederman 168789189557SYueHaibing if (parent) { 16880e47c99dSEric W. Biederman put_links(header); 1689938aaa4fSEric W. Biederman start_unregistering(header); 169089189557SYueHaibing } 169189189557SYueHaibing 1692938aaa4fSEric W. Biederman if (!--header->count) 1693938aaa4fSEric W. Biederman kfree_rcu(header, rcu); 16947ec66d06SEric W. Biederman 16957ec66d06SEric W. Biederman if (parent) 16967ec66d06SEric W. Biederman drop_sysctl_table(&parent->header); 1697938aaa4fSEric W. Biederman } 1698938aaa4fSEric W. Biederman 16991f87f0b5SEric W. Biederman /** 17001f87f0b5SEric W. Biederman * unregister_sysctl_table - unregister a sysctl table hierarchy 17011f87f0b5SEric W. Biederman * @header: the header returned from register_sysctl_table 17021f87f0b5SEric W. Biederman * 17031f87f0b5SEric W. Biederman * Unregisters the sysctl table and all children. proc entries may not 17041f87f0b5SEric W. Biederman * actually be removed until they are no longer used by anyone. 17051f87f0b5SEric W. Biederman */ 17061f87f0b5SEric W. Biederman void unregister_sysctl_table(struct ctl_table_header * header) 17071f87f0b5SEric W. Biederman { 1708f728019bSEric W. Biederman int nr_subheaders; 17091f87f0b5SEric W. Biederman might_sleep(); 17101f87f0b5SEric W. Biederman 17111f87f0b5SEric W. Biederman if (header == NULL) 17121f87f0b5SEric W. Biederman return; 17131f87f0b5SEric W. Biederman 1714f728019bSEric W. Biederman nr_subheaders = count_subheaders(header->ctl_table_arg); 1715f728019bSEric W. Biederman if (unlikely(nr_subheaders > 1)) { 1716f728019bSEric W. Biederman struct ctl_table_header **subheaders; 1717f728019bSEric W. Biederman int i; 1718f728019bSEric W. Biederman 1719f728019bSEric W. Biederman subheaders = (struct ctl_table_header **)(header + 1); 1720f728019bSEric W. Biederman for (i = nr_subheaders -1; i >= 0; i--) { 1721f728019bSEric W. Biederman struct ctl_table_header *subh = subheaders[i]; 1722f728019bSEric W. Biederman struct ctl_table *table = subh->ctl_table_arg; 1723f728019bSEric W. Biederman unregister_sysctl_table(subh); 1724f728019bSEric W. Biederman kfree(table); 1725f728019bSEric W. Biederman } 1726f728019bSEric W. Biederman kfree(header); 1727f728019bSEric W. Biederman return; 1728f728019bSEric W. Biederman } 1729f728019bSEric W. Biederman 17301f87f0b5SEric W. Biederman spin_lock(&sysctl_lock); 1731938aaa4fSEric W. Biederman drop_sysctl_table(header); 17321f87f0b5SEric W. Biederman spin_unlock(&sysctl_lock); 17331f87f0b5SEric W. Biederman } 17341f87f0b5SEric W. Biederman EXPORT_SYMBOL(unregister_sysctl_table); 17351f87f0b5SEric W. Biederman 17360e47c99dSEric W. Biederman void setup_sysctl_set(struct ctl_table_set *set, 17379eb47c26SEric W. Biederman struct ctl_table_root *root, 17381f87f0b5SEric W. Biederman int (*is_seen)(struct ctl_table_set *)) 17391f87f0b5SEric W. Biederman { 17401347440dSDan Carpenter memset(set, 0, sizeof(*set)); 17410e47c99dSEric W. Biederman set->is_seen = is_seen; 1742ac13ac6fSEric W. Biederman init_header(&set->dir.header, root, set, NULL, root_table); 17431f87f0b5SEric W. Biederman } 17441f87f0b5SEric W. Biederman 174597324cd8SEric W. Biederman void retire_sysctl_set(struct ctl_table_set *set) 174697324cd8SEric W. Biederman { 1747ac13ac6fSEric W. Biederman WARN_ON(!RB_EMPTY_ROOT(&set->dir.root)); 174897324cd8SEric W. Biederman } 17491f87f0b5SEric W. Biederman 17501e0edd3fSAlexey Dobriyan int __init proc_sys_init(void) 175177b14db5SEric W. Biederman { 1752e1675231SAlexey Dobriyan struct proc_dir_entry *proc_sys_root; 1753e1675231SAlexey Dobriyan 175477b14db5SEric W. Biederman proc_sys_root = proc_mkdir("sys", NULL); 17559043476fSAl Viro proc_sys_root->proc_iops = &proc_sys_dir_operations; 1756d56c0d45SAlexey Dobriyan proc_sys_root->proc_dir_ops = &proc_sys_dir_file_operations; 175777b14db5SEric W. Biederman proc_sys_root->nlink = 0; 1758de4e83bdSEric W. Biederman 1759de4e83bdSEric W. Biederman return sysctl_init(); 176077b14db5SEric W. Biederman } 17613db978d4SVlastimil Babka 17620a477e1aSVlastimil Babka struct sysctl_alias { 17630a477e1aSVlastimil Babka const char *kernel_param; 17640a477e1aSVlastimil Babka const char *sysctl_param; 17650a477e1aSVlastimil Babka }; 17660a477e1aSVlastimil Babka 17670a477e1aSVlastimil Babka /* 17680a477e1aSVlastimil Babka * Historically some settings had both sysctl and a command line parameter. 17690a477e1aSVlastimil Babka * With the generic sysctl. parameter support, we can handle them at a single 17700a477e1aSVlastimil Babka * place and only keep the historical name for compatibility. This is not meant 17710a477e1aSVlastimil Babka * to add brand new aliases. When adding existing aliases, consider whether 17720a477e1aSVlastimil Babka * the possibly different moment of changing the value (e.g. from early_param 17730a477e1aSVlastimil Babka * to the moment do_sysctl_args() is called) is an issue for the specific 17740a477e1aSVlastimil Babka * parameter. 17750a477e1aSVlastimil Babka */ 17760a477e1aSVlastimil Babka static const struct sysctl_alias sysctl_aliases[] = { 1777f117955aSGuilherme G. Piccoli {"hardlockup_all_cpu_backtrace", "kernel.hardlockup_all_cpu_backtrace" }, 1778b467f3efSVlastimil Babka {"hung_task_panic", "kernel.hung_task_panic" }, 1779f117955aSGuilherme G. Piccoli {"numa_zonelist_order", "vm.numa_zonelist_order" }, 1780f117955aSGuilherme G. Piccoli {"softlockup_all_cpu_backtrace", "kernel.softlockup_all_cpu_backtrace" }, 1781f117955aSGuilherme G. Piccoli {"softlockup_panic", "kernel.softlockup_panic" }, 17820a477e1aSVlastimil Babka { } 17830a477e1aSVlastimil Babka }; 17840a477e1aSVlastimil Babka 17850a477e1aSVlastimil Babka static const char *sysctl_find_alias(char *param) 17860a477e1aSVlastimil Babka { 17870a477e1aSVlastimil Babka const struct sysctl_alias *alias; 17880a477e1aSVlastimil Babka 17890a477e1aSVlastimil Babka for (alias = &sysctl_aliases[0]; alias->kernel_param != NULL; alias++) { 17900a477e1aSVlastimil Babka if (strcmp(alias->kernel_param, param) == 0) 17910a477e1aSVlastimil Babka return alias->sysctl_param; 17920a477e1aSVlastimil Babka } 17930a477e1aSVlastimil Babka 17940a477e1aSVlastimil Babka return NULL; 17950a477e1aSVlastimil Babka } 17960a477e1aSVlastimil Babka 17973db978d4SVlastimil Babka /* Set sysctl value passed on kernel command line. */ 17983db978d4SVlastimil Babka static int process_sysctl_arg(char *param, char *val, 17993db978d4SVlastimil Babka const char *unused, void *arg) 18003db978d4SVlastimil Babka { 18013db978d4SVlastimil Babka char *path; 18023db978d4SVlastimil Babka struct vfsmount **proc_mnt = arg; 18033db978d4SVlastimil Babka struct file_system_type *proc_fs_type; 18043db978d4SVlastimil Babka struct file *file; 18053db978d4SVlastimil Babka int len; 18063db978d4SVlastimil Babka int err; 18073db978d4SVlastimil Babka loff_t pos = 0; 18083db978d4SVlastimil Babka ssize_t wret; 18093db978d4SVlastimil Babka 18100a477e1aSVlastimil Babka if (strncmp(param, "sysctl", sizeof("sysctl") - 1) == 0) { 18113db978d4SVlastimil Babka param += sizeof("sysctl") - 1; 18123db978d4SVlastimil Babka 18133db978d4SVlastimil Babka if (param[0] != '/' && param[0] != '.') 18143db978d4SVlastimil Babka return 0; 18153db978d4SVlastimil Babka 18163db978d4SVlastimil Babka param++; 18170a477e1aSVlastimil Babka } else { 18180a477e1aSVlastimil Babka param = (char *) sysctl_find_alias(param); 18190a477e1aSVlastimil Babka if (!param) 18200a477e1aSVlastimil Babka return 0; 18210a477e1aSVlastimil Babka } 18223db978d4SVlastimil Babka 1823697edcb0SXiaoming Ni if (!val) 1824697edcb0SXiaoming Ni return -EINVAL; 1825697edcb0SXiaoming Ni len = strlen(val); 1826697edcb0SXiaoming Ni if (len == 0) 1827697edcb0SXiaoming Ni return -EINVAL; 1828697edcb0SXiaoming Ni 18293db978d4SVlastimil Babka /* 18303db978d4SVlastimil Babka * To set sysctl options, we use a temporary mount of proc, look up the 18313db978d4SVlastimil Babka * respective sys/ file and write to it. To avoid mounting it when no 18323db978d4SVlastimil Babka * options were given, we mount it only when the first sysctl option is 18333db978d4SVlastimil Babka * found. Why not a persistent mount? There are problems with a 18343db978d4SVlastimil Babka * persistent mount of proc in that it forces userspace not to use any 18353db978d4SVlastimil Babka * proc mount options. 18363db978d4SVlastimil Babka */ 18373db978d4SVlastimil Babka if (!*proc_mnt) { 18383db978d4SVlastimil Babka proc_fs_type = get_fs_type("proc"); 18393db978d4SVlastimil Babka if (!proc_fs_type) { 18403db978d4SVlastimil Babka pr_err("Failed to find procfs to set sysctl from command line\n"); 18413db978d4SVlastimil Babka return 0; 18423db978d4SVlastimil Babka } 18433db978d4SVlastimil Babka *proc_mnt = kern_mount(proc_fs_type); 18443db978d4SVlastimil Babka put_filesystem(proc_fs_type); 18453db978d4SVlastimil Babka if (IS_ERR(*proc_mnt)) { 18463db978d4SVlastimil Babka pr_err("Failed to mount procfs to set sysctl from command line\n"); 18473db978d4SVlastimil Babka return 0; 18483db978d4SVlastimil Babka } 18493db978d4SVlastimil Babka } 18503db978d4SVlastimil Babka 18513db978d4SVlastimil Babka path = kasprintf(GFP_KERNEL, "sys/%s", param); 18523db978d4SVlastimil Babka if (!path) 18533db978d4SVlastimil Babka panic("%s: Failed to allocate path for %s\n", __func__, param); 18543db978d4SVlastimil Babka strreplace(path, '.', '/'); 18553db978d4SVlastimil Babka 1856ffb37ca3SAl Viro file = file_open_root_mnt(*proc_mnt, path, O_WRONLY, 0); 18573db978d4SVlastimil Babka if (IS_ERR(file)) { 18583db978d4SVlastimil Babka err = PTR_ERR(file); 18593db978d4SVlastimil Babka if (err == -ENOENT) 18603db978d4SVlastimil Babka pr_err("Failed to set sysctl parameter '%s=%s': parameter not found\n", 18613db978d4SVlastimil Babka param, val); 18623db978d4SVlastimil Babka else if (err == -EACCES) 18633db978d4SVlastimil Babka pr_err("Failed to set sysctl parameter '%s=%s': permission denied (read-only?)\n", 18643db978d4SVlastimil Babka param, val); 18653db978d4SVlastimil Babka else 18663db978d4SVlastimil Babka pr_err("Error %pe opening proc file to set sysctl parameter '%s=%s'\n", 18673db978d4SVlastimil Babka file, param, val); 18683db978d4SVlastimil Babka goto out; 18693db978d4SVlastimil Babka } 18703db978d4SVlastimil Babka wret = kernel_write(file, val, len, &pos); 18713db978d4SVlastimil Babka if (wret < 0) { 18723db978d4SVlastimil Babka err = wret; 18733db978d4SVlastimil Babka if (err == -EINVAL) 18743db978d4SVlastimil Babka pr_err("Failed to set sysctl parameter '%s=%s': invalid value\n", 18753db978d4SVlastimil Babka param, val); 18763db978d4SVlastimil Babka else 18773db978d4SVlastimil Babka pr_err("Error %pe writing to proc file to set sysctl parameter '%s=%s'\n", 18783db978d4SVlastimil Babka ERR_PTR(err), param, val); 18793db978d4SVlastimil Babka } else if (wret != len) { 18803db978d4SVlastimil Babka pr_err("Wrote only %zd bytes of %d writing to proc file %s to set sysctl parameter '%s=%s\n", 18813db978d4SVlastimil Babka wret, len, path, param, val); 18823db978d4SVlastimil Babka } 18833db978d4SVlastimil Babka 18843db978d4SVlastimil Babka err = filp_close(file, NULL); 18853db978d4SVlastimil Babka if (err) 18863db978d4SVlastimil Babka pr_err("Error %pe closing proc file to set sysctl parameter '%s=%s\n", 18873db978d4SVlastimil Babka ERR_PTR(err), param, val); 18883db978d4SVlastimil Babka out: 18893db978d4SVlastimil Babka kfree(path); 18903db978d4SVlastimil Babka return 0; 18913db978d4SVlastimil Babka } 18923db978d4SVlastimil Babka 18933db978d4SVlastimil Babka void do_sysctl_args(void) 18943db978d4SVlastimil Babka { 18953db978d4SVlastimil Babka char *command_line; 18963db978d4SVlastimil Babka struct vfsmount *proc_mnt = NULL; 18973db978d4SVlastimil Babka 18983db978d4SVlastimil Babka command_line = kstrdup(saved_command_line, GFP_KERNEL); 18993db978d4SVlastimil Babka if (!command_line) 19003db978d4SVlastimil Babka panic("%s: Failed to allocate copy of command line\n", __func__); 19013db978d4SVlastimil Babka 19023db978d4SVlastimil Babka parse_args("Setting sysctl args", command_line, 19033db978d4SVlastimil Babka NULL, 0, -1, -1, &proc_mnt, process_sysctl_arg); 19043db978d4SVlastimil Babka 19053db978d4SVlastimil Babka if (proc_mnt) 19063db978d4SVlastimil Babka kern_unmount(proc_mnt); 19073db978d4SVlastimil Babka 19083db978d4SVlastimil Babka kfree(command_line); 19093db978d4SVlastimil Babka } 1910