diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c index 1febd412b4d29..e459cfd337117 100644 --- a/arch/arm64/kernel/armv8_deprecated.c +++ b/arch/arm64/kernel/armv8_deprecated.c @@ -569,7 +569,7 @@ static void __init register_insn_emulation(struct insn_emulation *insn) sysctl->extra2 = &insn->max; sysctl->proc_handler = emulation_proc_handler; - register_sysctl("abi", sysctl); + register_sysctl_sz("abi", sysctl, 1); } } diff --git a/arch/s390/appldata/appldata_base.c b/arch/s390/appldata/appldata_base.c index bbefe5e86bdfd..3b0994625652a 100644 --- a/arch/s390/appldata/appldata_base.c +++ b/arch/s390/appldata/appldata_base.c @@ -365,7 +365,7 @@ int appldata_register_ops(struct appldata_ops *ops) ops->ctl_table[0].proc_handler = appldata_generic_handler; ops->ctl_table[0].data = ops; - ops->sysctl_header = register_sysctl(appldata_proc_name, ops->ctl_table); + ops->sysctl_header = register_sysctl_sz(appldata_proc_name, ops->ctl_table, 1); if (!ops->sysctl_header) goto out; return 0; diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index bf06344a42cc6..7f3e536045ef4 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -19,8 +19,8 @@ #include #include "internal.h" -#define list_for_each_table_entry(entry, table) \ - for ((entry) = (table); (entry)->procname; (entry)++) +#define list_for_each_table_entry(entry, header) \ + for ((entry) = (header->ctl_table); (entry)->procname; (entry)++) static const struct dentry_operations proc_sys_dentry_operations; static const struct file_operations proc_sys_file_operations; @@ -43,7 +43,7 @@ static struct ctl_table sysctl_mount_point[] = { */ struct ctl_table_header *register_sysctl_mount_point(const char *path) { - return register_sysctl(path, sysctl_mount_point); + return register_sysctl_sz(path, sysctl_mount_point, 0); } EXPORT_SYMBOL(register_sysctl_mount_point); @@ -188,9 +188,10 @@ static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry) static void init_header(struct ctl_table_header *head, struct ctl_table_root *root, struct ctl_table_set *set, - struct ctl_node *node, struct ctl_table *table) + struct ctl_node *node, struct ctl_table *table, size_t table_size) { head->ctl_table = table; + head->ctl_table_size = table_size; head->ctl_table_arg = table; head->used = 0; head->count = 1; @@ -204,7 +205,7 @@ static void init_header(struct ctl_table_header *head, if (node) { struct ctl_table *entry; - list_for_each_table_entry(entry, table) { + list_for_each_table_entry(entry, head) { node->header = head; node++; } @@ -215,7 +216,7 @@ static void erase_header(struct ctl_table_header *head) { struct ctl_table *entry; - list_for_each_table_entry(entry, head->ctl_table) + list_for_each_table_entry(entry, head) erase_entry(head, entry); } @@ -242,7 +243,7 @@ static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) err = insert_links(header); if (err) goto fail_links; - list_for_each_table_entry(entry, header->ctl_table) { + list_for_each_table_entry(entry, header) { err = insert_entry(header, entry); if (err) goto fail; @@ -973,7 +974,7 @@ static struct ctl_dir *new_dir(struct ctl_table_set *set, memcpy(new_name, name, namelen); table[0].procname = new_name; table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO; - init_header(&new->header, set->dir.header.root, set, node, table); + init_header(&new->header, set->dir.header.root, set, node, table, 1); return new; } @@ -1125,11 +1126,11 @@ static int sysctl_check_table_array(const char *path, struct ctl_table *table) return err; } -static int sysctl_check_table(const char *path, struct ctl_table *table) +static int sysctl_check_table(const char *path, struct ctl_table_header *header) { struct ctl_table *entry; int err = 0; - list_for_each_table_entry(entry, table) { + list_for_each_table_entry(entry, header) { if ((entry->proc_handler == proc_dostring) || (entry->proc_handler == proc_dobool) || (entry->proc_handler == proc_dointvec) || @@ -1159,8 +1160,7 @@ static int sysctl_check_table(const char *path, struct ctl_table *table) return err; } -static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table *table, - struct ctl_table_root *link_root) +static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table_header *head) { struct ctl_table *link_table, *entry, *link; struct ctl_table_header *links; @@ -1170,7 +1170,7 @@ static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table name_bytes = 0; nr_entries = 0; - list_for_each_table_entry(entry, table) { + list_for_each_table_entry(entry, head) { nr_entries++; name_bytes += strlen(entry->procname) + 1; } @@ -1189,31 +1189,33 @@ static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table link_name = (char *)&link_table[nr_entries + 1]; link = link_table; - list_for_each_table_entry(entry, table) { + list_for_each_table_entry(entry, head) { int len = strlen(entry->procname) + 1; memcpy(link_name, entry->procname, len); link->procname = link_name; link->mode = S_IFLNK|S_IRWXUGO; - link->data = link_root; + link->data = head->root; link_name += len; link++; } - init_header(links, dir->header.root, dir->header.set, node, link_table); + init_header(links, dir->header.root, dir->header.set, node, link_table, + head->ctl_table_size); links->nreg = nr_entries; return links; } static bool get_links(struct ctl_dir *dir, - struct ctl_table *table, struct ctl_table_root *link_root) + struct ctl_table_header *header, + struct ctl_table_root *link_root) { - struct ctl_table_header *head; + struct ctl_table_header *tmp_head; struct ctl_table *entry, *link; /* Are there links available for every entry in table? */ - list_for_each_table_entry(entry, table) { + list_for_each_table_entry(entry, header) { const char *procname = entry->procname; - link = find_entry(&head, dir, procname, strlen(procname)); + link = find_entry(&tmp_head, dir, procname, strlen(procname)); if (!link) return false; if (S_ISDIR(link->mode) && S_ISDIR(entry->mode)) @@ -1224,10 +1226,10 @@ static bool get_links(struct ctl_dir *dir, } /* The checks passed. Increase the registration count on the links */ - list_for_each_table_entry(entry, table) { + list_for_each_table_entry(entry, header) { const char *procname = entry->procname; - link = find_entry(&head, dir, procname, strlen(procname)); - head->nreg++; + link = find_entry(&tmp_head, dir, procname, strlen(procname)); + tmp_head->nreg++; } return true; } @@ -1246,13 +1248,13 @@ static int insert_links(struct ctl_table_header *head) if (IS_ERR(core_parent)) return 0; - if (get_links(core_parent, head->ctl_table, head->root)) + if (get_links(core_parent, head, head->root)) return 0; core_parent->header.nreg++; spin_unlock(&sysctl_lock); - links = new_links(core_parent, head->ctl_table, head->root); + links = new_links(core_parent, head); spin_lock(&sysctl_lock); err = -ENOMEM; @@ -1260,7 +1262,7 @@ static int insert_links(struct ctl_table_header *head) goto out; err = 0; - if (get_links(core_parent, head->ctl_table, head->root)) { + if (get_links(core_parent, head, head->root)) { kfree(links); goto out; } @@ -1310,6 +1312,7 @@ static struct ctl_dir *sysctl_mkdir_p(struct ctl_dir *dir, const char *path) * should not be free'd after registration. So it should not be * used on stack. It can either be a global or dynamically allocated * by the caller and free'd later after sysctl unregistration. + * @table_size : The number of elements in table * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. @@ -1352,26 +1355,21 @@ static struct ctl_dir *sysctl_mkdir_p(struct ctl_dir *dir, const char *path) */ struct ctl_table_header *__register_sysctl_table( struct ctl_table_set *set, - const char *path, struct ctl_table *table) + const char *path, struct ctl_table *table, size_t table_size) { struct ctl_table_root *root = set->dir.header.root; struct ctl_table_header *header; struct ctl_dir *dir; - struct ctl_table *entry; struct ctl_node *node; - int nr_entries = 0; - - list_for_each_table_entry(entry, table) - nr_entries++; header = kzalloc(sizeof(struct ctl_table_header) + - sizeof(struct ctl_node)*nr_entries, GFP_KERNEL_ACCOUNT); + sizeof(struct ctl_node)*table_size, GFP_KERNEL_ACCOUNT); if (!header) return NULL; node = (struct ctl_node *)(header + 1); - init_header(header, root, set, node, table); - if (sysctl_check_table(path, table)) + init_header(header, root, set, node, table, table_size); + if (sysctl_check_table(path, header)) goto fail; spin_lock(&sysctl_lock); @@ -1401,7 +1399,7 @@ struct ctl_table_header *__register_sysctl_table( } /** - * register_sysctl - register a sysctl table + * register_sysctl_sz - register a sysctl table * @path: The path to the directory the sysctl table is in. If the path * doesn't exist we will create it for you. * @table: the table structure. The calller must ensure the life of the @table @@ -1411,18 +1409,20 @@ struct ctl_table_header *__register_sysctl_table( * to call unregister_sysctl_table() and can instead use something like * register_sysctl_init() which does not care for the result of the syctl * registration. + * @table_size: The number of elements in table. * * Register a sysctl table. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. * * See __register_sysctl_table for more details. */ -struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) +struct ctl_table_header *register_sysctl_sz(const char *path, struct ctl_table *table, + size_t table_size) { return __register_sysctl_table(&sysctl_table_root.default_set, - path, table); + path, table, table_size); } -EXPORT_SYMBOL(register_sysctl); +EXPORT_SYMBOL(register_sysctl_sz); /** * __register_sysctl_init() - register sysctl table to path @@ -1433,6 +1433,7 @@ EXPORT_SYMBOL(register_sysctl); * lifetime use of the sysctl. * @table_name: The name of sysctl table, only used for log printing when * registration fails + * @table_size: The number of elements in table * * The sysctl interface is used by userspace to query or modify at runtime * a predefined value set on a variable. These variables however have default @@ -1445,12 +1446,12 @@ EXPORT_SYMBOL(register_sysctl); * Context: if your base directory does not exist it will be created for you. */ void __init __register_sysctl_init(const char *path, struct ctl_table *table, - const char *table_name) + const char *table_name, size_t table_size) { - struct ctl_table_header *hdr = register_sysctl(path, table); + struct ctl_table_header *hdr = register_sysctl_sz(path, table, table_size); if (unlikely(!hdr)) { - pr_err("failed when register_sysctl %s to %s\n", table_name, path); + pr_err("failed when register_sysctl_sz %s to %s\n", table_name, path); return; } kmemleak_not_leak(hdr); @@ -1471,7 +1472,7 @@ static void put_links(struct ctl_table_header *header) if (IS_ERR(core_parent)) return; - list_for_each_table_entry(entry, header->ctl_table) { + list_for_each_table_entry(entry, header) { struct ctl_table_header *link_head; struct ctl_table *link; const char *name = entry->procname; @@ -1535,7 +1536,7 @@ void setup_sysctl_set(struct ctl_table_set *set, { memset(set, 0, sizeof(*set)); set->is_seen = is_seen; - init_header(&set->dir.header, root, set, NULL, root_table); + init_header(&set->dir.header, root, set, NULL, root_table, 1); } void retire_sysctl_set(struct ctl_table_set *set) diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 59d451f455bfb..09d7429d67c0e 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -159,12 +159,22 @@ struct ctl_node { struct ctl_table_header *header; }; -/* struct ctl_table_header is used to maintain dynamic lists of - struct ctl_table trees. */ +/** + * struct ctl_table_header - maintains dynamic lists of struct ctl_table trees + * @ctl_table: pointer to the first element in ctl_table array + * @ctl_table_size: number of elements pointed by @ctl_table + * @used: The entry will never be touched when equal to 0. + * @count: Upped every time something is added to @inodes and downed every time + * something is removed from inodes + * @nreg: When nreg drops to 0 the ctl_table_header will be unregistered. + * @rcu: Delays the freeing of the inode. Introduced with "unfuck proc_sysctl ->d_compare()" + * + */ struct ctl_table_header { union { struct { struct ctl_table *ctl_table; + int ctl_table_size; int used; int count; int nreg; @@ -205,6 +215,9 @@ struct ctl_path { const char *procname; }; +#define register_sysctl(path, table) \ + register_sysctl_sz(path, table, ARRAY_SIZE(table)) + #ifdef CONFIG_SYSCTL void proc_sys_poll_notify(struct ctl_table_poll *poll); @@ -216,14 +229,16 @@ extern void retire_sysctl_set(struct ctl_table_set *set); struct ctl_table_header *__register_sysctl_table( struct ctl_table_set *set, - const char *path, struct ctl_table *table); -struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table); + const char *path, struct ctl_table *table, size_t table_size); +struct ctl_table_header *register_sysctl_sz(const char *path, struct ctl_table *table, + size_t table_size); void unregister_sysctl_table(struct ctl_table_header * table); extern int sysctl_init_bases(void); extern void __register_sysctl_init(const char *path, struct ctl_table *table, - const char *table_name); -#define register_sysctl_init(path, table) __register_sysctl_init(path, table, #table) + const char *table_name, size_t table_size); +#define register_sysctl_init(path, table) \ + __register_sysctl_init(path, table, #table, ARRAY_SIZE(table)) extern struct ctl_table_header *register_sysctl_mount_point(const char *path); void do_sysctl_args(void); @@ -252,7 +267,9 @@ static inline struct ctl_table_header *register_sysctl_mount_point(const char *p return NULL; } -static inline struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) +static inline struct ctl_table_header *register_sysctl_sz(const char *path, + struct ctl_table *table, + size_t table_size) { return NULL; } diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c index 29c1d3ae2a5c8..01c4a50d22b2d 100644 --- a/ipc/ipc_sysctl.c +++ b/ipc/ipc_sysctl.c @@ -292,7 +292,9 @@ bool setup_ipc_sysctls(struct ipc_namespace *ns) tbl[i].data = NULL; } - ns->ipc_sysctls = __register_sysctl_table(&ns->ipc_set, "kernel", tbl); + ns->ipc_sysctls = __register_sysctl_table(&ns->ipc_set, + "kernel", tbl, + ARRAY_SIZE(ipc_sysctls)); } if (!ns->ipc_sysctls) { kfree(tbl); diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c index ce03930aced55..21fba3a6edaf7 100644 --- a/ipc/mq_sysctl.c +++ b/ipc/mq_sysctl.c @@ -145,7 +145,9 @@ bool setup_mq_sysctls(struct ipc_namespace *ns) tbl[i].data = NULL; } - ns->mq_sysctls = __register_sysctl_table(&ns->mq_set, "fs/mqueue", tbl); + ns->mq_sysctls = __register_sysctl_table(&ns->mq_set, + "fs/mqueue", tbl, + ARRAY_SIZE(mq_sysctls)); } if (!ns->mq_sysctls) { kfree(tbl); diff --git a/kernel/ucount.c b/kernel/ucount.c index 2c04589a61ff7..e188c25ed2b35 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -104,7 +104,8 @@ bool setup_userns_sysctls(struct user_namespace *ns) for (i = 0; i < UCOUNT_COUNTS; i++) { tbl[i].data = &ns->ucount_max[i]; } - ns->sysctls = __register_sysctl_table(&ns->set, "user", tbl); + ns->sysctls = __register_sysctl_table(&ns->set, "user", tbl, + ARRAY_SIZE(user_table)); } if (!ns->sysctls) { kfree(tbl); @@ -362,7 +363,7 @@ static __init int user_namespace_sysctl_init(void) * default set so that registrations in the child sets work * properly. */ - user_header = register_sysctl("user", empty); + user_header = register_sysctl_sz("user", empty, 0); kmemleak_ignore(user_header); BUG_ON(!user_header); BUG_ON(!setup_userns_sysctls(&init_user_ns)); diff --git a/net/sysctl_net.c b/net/sysctl_net.c index 4b45ed631eb8b..d9cbbb51b1431 100644 --- a/net/sysctl_net.c +++ b/net/sysctl_net.c @@ -101,7 +101,7 @@ __init int net_sysctl_init(void) * registering "/proc/sys/net" as an empty directory not in a * network namespace. */ - net_header = register_sysctl("net", empty); + net_header = register_sysctl_sz("net", empty, 0); if (!net_header) goto out; ret = register_pernet_subsys(&sysctl_pernet_ops); @@ -163,10 +163,16 @@ static void ensure_safe_net_sysctl(struct net *net, const char *path, struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, struct ctl_table *table) { + int count = 0; + struct ctl_table *entry; + if (!net_eq(net, &init_net)) ensure_safe_net_sysctl(net, path, table); - return __register_sysctl_table(&net->sysctls, path, table); + for (entry = table; entry->procname; entry++) + count++; + + return __register_sysctl_table(&net->sysctls, path, table, count); } EXPORT_SYMBOL_GPL(register_net_sysctl);