summaryrefslogtreecommitdiff
path: root/fs/proc/proc_sysctl.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/proc/proc_sysctl.c')
-rw-r--r--fs/proc/proc_sysctl.c838
1 files changed, 355 insertions, 483 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 42c5128c7d1c..49ab74e0bfde 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -12,42 +12,52 @@
#include <linux/cred.h>
#include <linux/namei.h>
#include <linux/mm.h>
+#include <linux/uio.h>
#include <linux/module.h>
#include <linux/bpf-cgroup.h>
#include <linux/mount.h>
+#include <linux/kmemleak.h>
+#include <linux/lockdep.h>
#include "internal.h"
+#define list_for_each_table_entry(entry, header) \
+ entry = header->ctl_table; \
+ for (size_t i = 0 ; i < header->ctl_table_size; ++i, entry++)
+
static const struct dentry_operations proc_sys_dentry_operations;
static const struct file_operations proc_sys_file_operations;
static const struct inode_operations proc_sys_inode_operations;
static const struct file_operations proc_sys_dir_file_operations;
static const struct inode_operations proc_sys_dir_operations;
-/* shared constants to be used in various sysctls */
-const int sysctl_vals[] = { 0, 1, INT_MAX };
-EXPORT_SYMBOL(sysctl_vals);
-
-/* Support for permanently empty directories */
-
-struct ctl_table sysctl_mount_point[] = {
+/*
+ * Support for permanently empty directories.
+ * Must be non-empty to avoid sharing an address with other tables.
+ */
+static const struct ctl_table sysctl_mount_point[] = {
{ }
};
-static bool is_empty_dir(struct ctl_table_header *head)
-{
- return head->ctl_table[0].child == sysctl_mount_point;
-}
-
-static void set_empty_dir(struct ctl_dir *dir)
+/**
+ * register_sysctl_mount_point() - registers a sysctl mount point
+ * @path: path for the mount point
+ *
+ * Used to create a permanently empty directory to serve as mount point.
+ * There are some subtle but important permission checks this allows in the
+ * case of unprivileged mounts.
+ */
+struct ctl_table_header *register_sysctl_mount_point(const char *path)
{
- dir->header.ctl_table[0].child = sysctl_mount_point;
+ return register_sysctl_sz(path, sysctl_mount_point, 0);
}
+EXPORT_SYMBOL(register_sysctl_mount_point);
-static void clear_empty_dir(struct ctl_dir *dir)
-
-{
- dir->header.ctl_table[0].child = NULL;
-}
+#define sysctl_is_perm_empty_ctl_header(hptr) \
+ (hptr->type == SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY)
+#define sysctl_set_perm_empty_ctl_header(hptr) \
+ (hptr->type = SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY)
+#define sysctl_clear_perm_empty_ctl_header(hptr) \
+ (hptr->type = SYSCTL_TABLE_TYPE_DEFAULT)
void proc_sys_poll_notify(struct ctl_table_poll *poll)
{
@@ -58,12 +68,11 @@ void proc_sys_poll_notify(struct ctl_table_poll *poll)
wake_up_interruptible(&poll->wait);
}
-static struct ctl_table root_table[] = {
+static const struct ctl_table root_table[] = {
{
.procname = "",
.mode = S_IFDIR|S_IRUGO|S_IXUGO,
},
- { }
};
static struct ctl_table_root sysctl_table_root = {
.default_set.dir.header = {
@@ -80,7 +89,7 @@ static DEFINE_SPINLOCK(sysctl_lock);
static void drop_sysctl_table(struct ctl_table_header *header);
static int sysctl_follow_link(struct ctl_table_header **phead,
- struct ctl_table **pentry);
+ const struct ctl_table **pentry);
static int insert_links(struct ctl_table_header *head);
static void put_links(struct ctl_table_header *header);
@@ -93,27 +102,23 @@ static void sysctl_print_dir(struct ctl_dir *dir)
static int namecmp(const char *name1, int len1, const char *name2, int len2)
{
- int minlen;
int cmp;
- minlen = len1;
- if (minlen > len2)
- minlen = len2;
-
- cmp = memcmp(name1, name2, minlen);
+ cmp = memcmp(name1, name2, min(len1, len2));
if (cmp == 0)
cmp = len1 - len2;
return cmp;
}
-/* Called under sysctl_lock */
-static struct ctl_table *find_entry(struct ctl_table_header **phead,
+static const struct ctl_table *find_entry(struct ctl_table_header **phead,
struct ctl_dir *dir, const char *name, int namelen)
{
struct ctl_table_header *head;
- struct ctl_table *entry;
+ const struct ctl_table *entry;
struct rb_node *node = dir->root.rb_node;
+ lockdep_assert_held(&sysctl_lock);
+
while (node)
{
struct ctl_node *ctl_node;
@@ -138,7 +143,7 @@ static struct ctl_table *find_entry(struct ctl_table_header **phead,
return NULL;
}
-static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry)
+static int insert_entry(struct ctl_table_header *head, const struct ctl_table *entry)
{
struct rb_node *node = &head->node[entry - head->ctl_table].node;
struct rb_node **p = &head->parent->root.rb_node;
@@ -148,7 +153,7 @@ static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry)
while (*p) {
struct ctl_table_header *parent_head;
- struct ctl_table *parent_entry;
+ const struct ctl_table *parent_entry;
struct ctl_node *parent_node;
const char *parent_name;
int cmp;
@@ -167,7 +172,7 @@ static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry)
else {
pr_err("sysctl duplicate entry: ");
sysctl_print_dir(head->parent);
- pr_cont("/%s\n", entry->procname);
+ pr_cont("%s\n", entry->procname);
return -EEXIST;
}
}
@@ -177,7 +182,7 @@ static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry)
return 0;
}
-static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry)
+static void erase_entry(struct ctl_table_header *head, const struct ctl_table *entry)
{
struct rb_node *node = &head->node[entry - head->ctl_table].node;
@@ -186,9 +191,10 @@ 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, const 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;
@@ -200,41 +206,49 @@ static void init_header(struct ctl_table_header *head,
head->node = node;
INIT_HLIST_HEAD(&head->inodes);
if (node) {
- struct ctl_table *entry;
- for (entry = table; entry->procname; entry++, node++)
+ const struct ctl_table *entry;
+
+ list_for_each_table_entry(entry, head) {
node->header = head;
+ node++;
+ }
}
+ if (table == sysctl_mount_point)
+ sysctl_set_perm_empty_ctl_header(head);
}
static void erase_header(struct ctl_table_header *head)
{
- struct ctl_table *entry;
- for (entry = head->ctl_table; entry->procname; entry++)
+ const struct ctl_table *entry;
+
+ list_for_each_table_entry(entry, head)
erase_entry(head, entry);
}
static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header)
{
- struct ctl_table *entry;
+ const struct ctl_table *entry;
+ struct ctl_table_header *dir_h = &dir->header;
int err;
+
/* Is this a permanently empty directory? */
- if (is_empty_dir(&dir->header))
+ if (sysctl_is_perm_empty_ctl_header(dir_h))
return -EROFS;
/* Am I creating a permanently empty directory? */
- if (header->ctl_table == sysctl_mount_point) {
+ if (sysctl_is_perm_empty_ctl_header(header)) {
if (!RB_EMPTY_ROOT(&dir->root))
return -EINVAL;
- set_empty_dir(dir);
+ sysctl_set_perm_empty_ctl_header(dir_h);
}
- dir->header.nreg++;
+ dir_h->nreg++;
header->parent = dir;
err = insert_links(header);
if (err)
goto fail_links;
- for (entry = header->ctl_table; entry->procname; entry++) {
+ list_for_each_table_entry(entry, header) {
err = insert_entry(header, entry);
if (err)
goto fail;
@@ -245,24 +259,26 @@ fail:
put_links(header);
fail_links:
if (header->ctl_table == sysctl_mount_point)
- clear_empty_dir(dir);
+ sysctl_clear_perm_empty_ctl_header(dir_h);
header->parent = NULL;
- drop_sysctl_table(&dir->header);
+ drop_sysctl_table(dir_h);
return err;
}
-/* called under sysctl_lock */
static int use_table(struct ctl_table_header *p)
{
+ lockdep_assert_held(&sysctl_lock);
+
if (unlikely(p->unregistering))
return 0;
p->used++;
return 1;
}
-/* called under sysctl_lock */
static void unuse_table(struct ctl_table_header *p)
{
+ lockdep_assert_held(&sysctl_lock);
+
if (!--p->used)
if (unlikely(p->unregistering))
complete(p->unregistering);
@@ -273,9 +289,11 @@ static void proc_sys_invalidate_dcache(struct ctl_table_header *head)
proc_invalidate_siblings_dcache(&head->inodes, &sysctl_lock);
}
-/* called under sysctl_lock, will reacquire if has to wait */
static void start_unregistering(struct ctl_table_header *p)
{
+ /* will reacquire if has to wait */
+ lockdep_assert_held(&sysctl_lock);
+
/*
* if p->used is 0, nobody will ever touch that entry again;
* we'll eliminate all paths to it before dropping sysctl_lock
@@ -332,12 +350,12 @@ lookup_header_set(struct ctl_table_root *root)
return set;
}
-static struct ctl_table *lookup_entry(struct ctl_table_header **phead,
- struct ctl_dir *dir,
- const char *name, int namelen)
+static const struct ctl_table *lookup_entry(struct ctl_table_header **phead,
+ struct ctl_dir *dir,
+ const char *name, int namelen)
{
struct ctl_table_header *head;
- struct ctl_table *entry;
+ const struct ctl_table *entry;
spin_lock(&sysctl_lock);
entry = find_entry(&head, dir, name, namelen);
@@ -362,10 +380,10 @@ static struct ctl_node *first_usable_entry(struct rb_node *node)
}
static void first_entry(struct ctl_dir *dir,
- struct ctl_table_header **phead, struct ctl_table **pentry)
+ struct ctl_table_header **phead, const struct ctl_table **pentry)
{
struct ctl_table_header *head = NULL;
- struct ctl_table *entry = NULL;
+ const struct ctl_table *entry = NULL;
struct ctl_node *ctl_node;
spin_lock(&sysctl_lock);
@@ -379,10 +397,10 @@ static void first_entry(struct ctl_dir *dir,
*pentry = entry;
}
-static void next_entry(struct ctl_table_header **phead, struct ctl_table **pentry)
+static void next_entry(struct ctl_table_header **phead, const struct ctl_table **pentry)
{
struct ctl_table_header *head = *phead;
- struct ctl_table *entry = *pentry;
+ const struct ctl_table *entry = *pentry;
struct ctl_node *ctl_node = &head->node[entry - head->ctl_table];
spin_lock(&sysctl_lock);
@@ -415,7 +433,7 @@ static int test_perm(int mode, int op)
return -EACCES;
}
-static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, int op)
+static int sysctl_perm(struct ctl_table_header *head, const struct ctl_table *table, int op)
{
struct ctl_table_root *root = head->root;
int mode;
@@ -429,7 +447,7 @@ static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, i
}
static struct inode *proc_sys_make_inode(struct super_block *sb,
- struct ctl_table_header *head, struct ctl_table *table)
+ struct ctl_table_header *head, const struct ctl_table *table)
{
struct ctl_table_root *root = head->root;
struct inode *inode;
@@ -455,7 +473,7 @@ static struct inode *proc_sys_make_inode(struct super_block *sb,
head->count++;
spin_unlock(&sysctl_lock);
- inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
+ simple_inode_init_ts(inode);
inode->i_mode = table->mode;
if (!S_ISDIR(table->mode)) {
inode->i_mode |= S_IFREG;
@@ -465,16 +483,14 @@ static struct inode *proc_sys_make_inode(struct super_block *sb,
inode->i_mode |= S_IFDIR;
inode->i_op = &proc_sys_dir_operations;
inode->i_fop = &proc_sys_dir_file_operations;
- if (is_empty_dir(head))
+ if (sysctl_is_perm_empty_ctl_header(head))
make_empty_dir_inode(inode);
}
+ inode->i_uid = GLOBAL_ROOT_UID;
+ inode->i_gid = GLOBAL_ROOT_GID;
if (root->set_ownership)
- root->set_ownership(head, table, &inode->i_uid, &inode->i_gid);
- else {
- inode->i_uid = GLOBAL_ROOT_UID;
- inode->i_gid = GLOBAL_ROOT_GID;
- }
+ root->set_ownership(head, &inode->i_uid, &inode->i_gid);
return inode;
}
@@ -502,7 +518,7 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
struct ctl_table_header *head = grab_header(dir);
struct ctl_table_header *h = NULL;
const struct qstr *name = &dentry->d_name;
- struct ctl_table *p;
+ const struct ctl_table *p;
struct inode *inode;
struct dentry *err = ERR_PTR(-ENOENT);
struct ctl_dir *ctl_dir;
@@ -525,13 +541,7 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
}
inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p);
- if (IS_ERR(inode)) {
- err = ERR_CAST(inode);
- goto out;
- }
-
- d_set_d_op(dentry, &proc_sys_dentry_operations);
- err = d_splice_alias(inode, dentry);
+ err = d_splice_alias_ops(inode, dentry, &proc_sys_dentry_operations);
out:
if (h)
@@ -540,13 +550,14 @@ out:
return err;
}
-static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
- size_t count, loff_t *ppos, int write)
+static ssize_t proc_sys_call_handler(struct kiocb *iocb, struct iov_iter *iter,
+ int write)
{
- struct inode *inode = file_inode(filp);
+ struct inode *inode = file_inode(iocb->ki_filp);
struct ctl_table_header *head = grab_header(inode);
- struct ctl_table *table = PROC_I(inode)->sysctl_entry;
- void *kbuf;
+ const struct ctl_table *table = PROC_I(inode)->sysctl_entry;
+ size_t count = iov_iter_count(iter);
+ char *kbuf;
ssize_t error;
if (IS_ERR(head))
@@ -566,63 +577,59 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
goto out;
/* don't even try if the size is too large */
- if (count > KMALLOC_MAX_SIZE)
- return -ENOMEM;
+ error = -ENOMEM;
+ if (count >= KMALLOC_MAX_SIZE)
+ goto out;
+ kbuf = kvzalloc(count + 1, GFP_KERNEL);
+ if (!kbuf)
+ goto out;
if (write) {
- kbuf = memdup_user_nul(ubuf, count);
- if (IS_ERR(kbuf)) {
- error = PTR_ERR(kbuf);
- goto out;
- }
- } else {
- error = -ENOMEM;
- kbuf = kzalloc(count, GFP_KERNEL);
- if (!kbuf)
- goto out;
+ error = -EFAULT;
+ if (!copy_from_iter_full(kbuf, count, iter))
+ goto out_free_buf;
+ kbuf[count] = '\0';
}
error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, &kbuf, &count,
- ppos);
+ &iocb->ki_pos);
if (error)
goto out_free_buf;
/* careful: calling conventions are nasty here */
- error = table->proc_handler(table, write, kbuf, &count, ppos);
+ error = table->proc_handler(table, write, kbuf, &count, &iocb->ki_pos);
if (error)
goto out_free_buf;
if (!write) {
error = -EFAULT;
- if (copy_to_user(ubuf, kbuf, count))
+ if (copy_to_iter(kbuf, count, iter) < count)
goto out_free_buf;
}
error = count;
out_free_buf:
- kfree(kbuf);
+ kvfree(kbuf);
out:
sysctl_head_finish(head);
return error;
}
-static ssize_t proc_sys_read(struct file *filp, char __user *buf,
- size_t count, loff_t *ppos)
+static ssize_t proc_sys_read(struct kiocb *iocb, struct iov_iter *iter)
{
- return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0);
+ return proc_sys_call_handler(iocb, iter, 0);
}
-static ssize_t proc_sys_write(struct file *filp, const char __user *buf,
- size_t count, loff_t *ppos)
+static ssize_t proc_sys_write(struct kiocb *iocb, struct iov_iter *iter)
{
- return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1);
+ return proc_sys_call_handler(iocb, iter, 1);
}
static int proc_sys_open(struct inode *inode, struct file *filp)
{
struct ctl_table_header *head = grab_header(inode);
- struct ctl_table *table = PROC_I(inode)->sysctl_entry;
+ const struct ctl_table *table = PROC_I(inode)->sysctl_entry;
/* sysctl was unregistered */
if (IS_ERR(head))
@@ -640,7 +647,7 @@ static __poll_t proc_sys_poll(struct file *filp, poll_table *wait)
{
struct inode *inode = file_inode(filp);
struct ctl_table_header *head = grab_header(inode);
- struct ctl_table *table = PROC_I(inode)->sysctl_entry;
+ const struct ctl_table *table = PROC_I(inode)->sysctl_entry;
__poll_t ret = DEFAULT_POLLMASK;
unsigned long event;
@@ -671,7 +678,7 @@ out:
static bool proc_sys_fill_cache(struct file *file,
struct dir_context *ctx,
struct ctl_table_header *head,
- struct ctl_table *table)
+ const struct ctl_table *table)
{
struct dentry *child, *dir = file->f_path.dentry;
struct inode *inode;
@@ -692,20 +699,15 @@ static bool proc_sys_fill_cache(struct file *file,
if (d_in_lookup(child)) {
struct dentry *res;
inode = proc_sys_make_inode(dir->d_sb, head, table);
- if (IS_ERR(inode)) {
- d_lookup_done(child);
- dput(child);
- return false;
- }
- d_set_d_op(child, &proc_sys_dentry_operations);
- res = d_splice_alias(inode, child);
+ res = d_splice_alias_ops(inode, child,
+ &proc_sys_dentry_operations);
d_lookup_done(child);
if (unlikely(res)) {
- if (IS_ERR(res)) {
- dput(child);
- return false;
- }
dput(child);
+
+ if (IS_ERR(res))
+ return false;
+
child = res;
}
}
@@ -720,7 +722,7 @@ static bool proc_sys_fill_cache(struct file *file,
static bool proc_sys_link_fill_cache(struct file *file,
struct dir_context *ctx,
struct ctl_table_header *head,
- struct ctl_table *table)
+ const struct ctl_table *table)
{
bool ret = true;
@@ -738,7 +740,7 @@ out:
return ret;
}
-static int scan(struct ctl_table_header *head, struct ctl_table *table,
+static int scan(struct ctl_table_header *head, const struct ctl_table *table,
unsigned long *pos, struct file *file,
struct dir_context *ctx)
{
@@ -762,7 +764,7 @@ static int proc_sys_readdir(struct file *file, struct dir_context *ctx)
{
struct ctl_table_header *head = grab_header(file_inode(file));
struct ctl_table_header *h = NULL;
- struct ctl_table *entry;
+ const struct ctl_table *entry;
struct ctl_dir *ctl_dir;
unsigned long pos;
@@ -787,14 +789,15 @@ out:
return 0;
}
-static int proc_sys_permission(struct inode *inode, int mask)
+static int proc_sys_permission(struct mnt_idmap *idmap,
+ struct inode *inode, int mask)
{
/*
* sysctl entries that are not writeable,
* are _NOT_ writeable, capabilities or not.
*/
struct ctl_table_header *head;
- struct ctl_table *table;
+ const struct ctl_table *table;
int error;
/* Executable files are not allowed under /proc/sys/ */
@@ -815,7 +818,8 @@ static int proc_sys_permission(struct inode *inode, int mask)
return error;
}
-static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr)
+static int proc_sys_setattr(struct mnt_idmap *idmap,
+ struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = d_inode(dentry);
int error;
@@ -823,26 +827,26 @@ static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr)
if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))
return -EPERM;
- error = setattr_prepare(dentry, attr);
+ error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
if (error)
return error;
- setattr_copy(inode, attr);
- mark_inode_dirty(inode);
+ setattr_copy(&nop_mnt_idmap, inode, attr);
return 0;
}
-static int proc_sys_getattr(const struct path *path, struct kstat *stat,
+static int proc_sys_getattr(struct mnt_idmap *idmap,
+ const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int query_flags)
{
struct inode *inode = d_inode(path->dentry);
struct ctl_table_header *head = grab_header(inode);
- struct ctl_table *table = PROC_I(inode)->sysctl_entry;
+ const struct ctl_table *table = PROC_I(inode)->sysctl_entry;
if (IS_ERR(head))
return PTR_ERR(head);
- generic_fillattr(inode, stat);
+ generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
if (table)
stat->mode = (stat->mode & S_IFMT) | table->mode;
@@ -853,8 +857,10 @@ static int proc_sys_getattr(const struct path *path, struct kstat *stat,
static const struct file_operations proc_sys_file_operations = {
.open = proc_sys_open,
.poll = proc_sys_poll,
- .read = proc_sys_read,
- .write = proc_sys_write,
+ .read_iter = proc_sys_read,
+ .write_iter = proc_sys_write,
+ .splice_read = copy_splice_read,
+ .splice_write = iter_file_splice_write,
.llseek = default_llseek,
};
@@ -877,7 +883,8 @@ static const struct inode_operations proc_sys_dir_operations = {
.getattr = proc_sys_getattr,
};
-static int proc_sys_revalidate(struct dentry *dentry, unsigned int flags)
+static int proc_sys_revalidate(struct inode *dir, const struct qstr *name,
+ struct dentry *dentry, unsigned int flags)
{
if (flags & LOOKUP_RCU)
return -ECHILD;
@@ -910,17 +917,21 @@ static int proc_sys_compare(const struct dentry *dentry,
struct ctl_table_header *head;
struct inode *inode;
- /* Although proc doesn't have negative dentries, rcu-walk means
- * that inode here can be NULL */
- /* AV: can it, indeed? */
- inode = d_inode_rcu(dentry);
- if (!inode)
- return 1;
if (name->len != len)
return 1;
if (memcmp(name->name, str, len))
return 1;
- head = rcu_dereference(PROC_I(inode)->sysctl);
+
+ // false positive is fine here - we'll recheck anyway
+ if (d_in_lookup(dentry))
+ return 0;
+
+ inode = d_inode_rcu(dentry);
+ // we just might have run into dentry in the middle of __dentry_kill()
+ if (!inode)
+ return 1;
+
+ head = READ_ONCE(PROC_I(inode)->sysctl);
return !head || !sysctl_is_seen(head);
}
@@ -934,7 +945,7 @@ static struct ctl_dir *find_subdir(struct ctl_dir *dir,
const char *name, int namelen)
{
struct ctl_table_header *head;
- struct ctl_table *entry;
+ const struct ctl_table *entry;
entry = find_entry(&head, dir, name, namelen);
if (!entry)
@@ -953,19 +964,18 @@ static struct ctl_dir *new_dir(struct ctl_table_set *set,
char *new_name;
new = kzalloc(sizeof(*new) + sizeof(struct ctl_node) +
- sizeof(struct ctl_table)*2 + namelen + 1,
+ sizeof(struct ctl_table) + namelen + 1,
GFP_KERNEL);
if (!new)
return NULL;
node = (struct ctl_node *)(new + 1);
table = (struct ctl_table *)(node + 1);
- new_name = (char *)(table + 2);
+ new_name = (char *)(table + 1);
memcpy(new_name, name, namelen);
- new_name[namelen] = '\0';
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;
}
@@ -1022,8 +1032,8 @@ failed:
if (IS_ERR(subdir)) {
pr_err("sysctl could not get directory: ");
sysctl_print_dir(dir);
- pr_cont("/%*.*s %ld\n",
- namelen, namelen, name, PTR_ERR(subdir));
+ pr_cont("%*.*s %ld\n", namelen, namelen, name,
+ PTR_ERR(subdir));
}
drop_sysctl_table(&dir->header);
if (new)
@@ -1046,16 +1056,15 @@ static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir)
}
static int sysctl_follow_link(struct ctl_table_header **phead,
- struct ctl_table **pentry)
+ const struct ctl_table **pentry)
{
struct ctl_table_header *head;
+ const struct ctl_table *entry;
struct ctl_table_root *root;
struct ctl_table_set *set;
- struct ctl_table *entry;
struct ctl_dir *dir;
int ret;
- ret = 0;
spin_lock(&sysctl_lock);
root = (*pentry)->data;
set = lookup_header_set(root);
@@ -1079,7 +1088,7 @@ static int sysctl_follow_link(struct ctl_table_header **phead,
return ret;
}
-static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...)
+static int sysctl_err(const char *path, const struct ctl_table *table, char *fmt, ...)
{
struct va_format vaf;
va_list args;
@@ -1095,8 +1104,9 @@ static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...)
return -EINVAL;
}
-static int sysctl_check_table_array(const char *path, struct ctl_table *table)
+static int sysctl_check_table_array(const char *path, const struct ctl_table *table)
{
+ unsigned int extra;
int err = 0;
if ((table->proc_handler == proc_douintvec) ||
@@ -1105,62 +1115,85 @@ static int sysctl_check_table_array(const char *path, struct ctl_table *table)
err |= sysctl_err(path, table, "array not allowed");
}
+ if (table->proc_handler == proc_dou8vec_minmax) {
+ if (table->maxlen != sizeof(u8))
+ err |= sysctl_err(path, table, "array not allowed");
+
+ if (table->extra1) {
+ extra = *(unsigned int *) table->extra1;
+ if (extra > 255U)
+ err |= sysctl_err(path, table,
+ "range value too large for proc_dou8vec_minmax");
+ }
+ if (table->extra2) {
+ extra = *(unsigned int *) table->extra2;
+ if (extra > 255U)
+ err |= sysctl_err(path, table,
+ "range value too large for proc_dou8vec_minmax");
+ }
+ }
+
+ if (table->proc_handler == proc_dobool) {
+ if (table->maxlen != sizeof(bool))
+ err |= sysctl_err(path, table, "array not allowed");
+ }
+
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)
{
+ const struct ctl_table *entry;
int err = 0;
- for (; table->procname; table++) {
- if (table->child)
- err |= sysctl_err(path, table, "Not a file");
-
- if ((table->proc_handler == proc_dostring) ||
- (table->proc_handler == proc_dointvec) ||
- (table->proc_handler == proc_douintvec) ||
- (table->proc_handler == proc_douintvec_minmax) ||
- (table->proc_handler == proc_dointvec_minmax) ||
- (table->proc_handler == proc_dointvec_jiffies) ||
- (table->proc_handler == proc_dointvec_userhz_jiffies) ||
- (table->proc_handler == proc_dointvec_ms_jiffies) ||
- (table->proc_handler == proc_doulongvec_minmax) ||
- (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) {
- if (!table->data)
- err |= sysctl_err(path, table, "No data");
- if (!table->maxlen)
- err |= sysctl_err(path, table, "No maxlen");
+ list_for_each_table_entry(entry, header) {
+ if (!entry->procname)
+ err |= sysctl_err(path, entry, "procname is null");
+ if ((entry->proc_handler == proc_dostring) ||
+ (entry->proc_handler == proc_dobool) ||
+ (entry->proc_handler == proc_dointvec) ||
+ (entry->proc_handler == proc_douintvec) ||
+ (entry->proc_handler == proc_douintvec_minmax) ||
+ (entry->proc_handler == proc_dointvec_minmax) ||
+ (entry->proc_handler == proc_dou8vec_minmax) ||
+ (entry->proc_handler == proc_dointvec_jiffies) ||
+ (entry->proc_handler == proc_dointvec_userhz_jiffies) ||
+ (entry->proc_handler == proc_dointvec_ms_jiffies) ||
+ (entry->proc_handler == proc_doulongvec_minmax) ||
+ (entry->proc_handler == proc_doulongvec_ms_jiffies_minmax)) {
+ if (!entry->data)
+ err |= sysctl_err(path, entry, "No data");
+ if (!entry->maxlen)
+ err |= sysctl_err(path, entry, "No maxlen");
else
- err |= sysctl_check_table_array(path, table);
+ err |= sysctl_check_table_array(path, entry);
}
- if (!table->proc_handler)
- err |= sysctl_err(path, table, "No proc_handler");
+ if (!entry->proc_handler)
+ err |= sysctl_err(path, entry, "No proc_handler");
- if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode)
- err |= sysctl_err(path, table, "bogus .mode 0%o",
- table->mode);
+ if ((entry->mode & (S_IRUGO|S_IWUGO)) != entry->mode)
+ err |= sysctl_err(path, entry, "bogus .mode 0%o",
+ entry->mode);
}
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 *link_table, *link;
struct ctl_table_header *links;
+ const struct ctl_table *entry;
struct ctl_node *node;
char *link_name;
- int nr_entries, name_bytes;
+ int name_bytes;
name_bytes = 0;
- nr_entries = 0;
- for (entry = table; entry->procname; entry++) {
- nr_entries++;
+ list_for_each_table_entry(entry, head) {
name_bytes += strlen(entry->procname) + 1;
}
links = kzalloc(sizeof(struct ctl_table_header) +
- sizeof(struct ctl_node)*nr_entries +
- sizeof(struct ctl_table)*(nr_entries + 1) +
+ sizeof(struct ctl_node)*head->ctl_table_size +
+ sizeof(struct ctl_table)*head->ctl_table_size +
name_bytes,
GFP_KERNEL);
@@ -1168,33 +1201,41 @@ static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table
return NULL;
node = (struct ctl_node *)(links + 1);
- link_table = (struct ctl_table *)(node + nr_entries);
- link_name = (char *)&link_table[nr_entries + 1];
+ link_table = (struct ctl_table *)(node + head->ctl_table_size);
+ link_name = (char *)(link_table + head->ctl_table_size);
+ link = link_table;
- for (link = link_table, entry = table; entry->procname; link++, entry++) {
+ 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);
- links->nreg = nr_entries;
+ init_header(links, dir->header.root, dir->header.set, node, link_table,
+ head->ctl_table_size);
+ links->nreg = head->ctl_table_size;
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 *entry, *link;
+ struct ctl_table_header *tmp_head;
+ const struct ctl_table *entry, *link;
+
+ if (header->ctl_table_size == 0 ||
+ sysctl_is_perm_empty_ctl_header(header))
+ return true;
/* Are there links available for every entry in table? */
- for (entry = table; entry->procname; entry++) {
+ 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))
@@ -1205,10 +1246,10 @@ static bool get_links(struct ctl_dir *dir,
}
/* The checks passed. Increase the registration count on the links */
- for (entry = table; entry->procname; entry++) {
+ 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;
}
@@ -1216,7 +1257,7 @@ static bool get_links(struct ctl_dir *dir,
static int insert_links(struct ctl_table_header *head)
{
struct ctl_table_set *root_set = &sysctl_table_root.default_set;
- struct ctl_dir *core_parent = NULL;
+ struct ctl_dir *core_parent;
struct ctl_table_header *links;
int err;
@@ -1227,13 +1268,13 @@ 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;
@@ -1241,7 +1282,7 @@ 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;
}
@@ -1254,34 +1295,64 @@ out:
return err;
}
+/* Find the directory for the ctl_table. If one is not found create it. */
+static struct ctl_dir *sysctl_mkdir_p(struct ctl_dir *dir, const char *path)
+{
+ const char *name, *nextname;
+
+ for (name = path; name; name = nextname) {
+ int namelen;
+ nextname = strchr(name, '/');
+ if (nextname) {
+ namelen = nextname - name;
+ nextname++;
+ } else {
+ namelen = strlen(name);
+ }
+ if (namelen == 0)
+ continue;
+
+ /*
+ * namelen ensures if name is "foo/bar/yay" only foo is
+ * registered first. We traverse as if using mkdir -p and
+ * return a ctl_dir for the last directory entry.
+ */
+ dir = get_subdir(dir, name, namelen);
+ if (IS_ERR(dir))
+ break;
+ }
+ return dir;
+}
+
/**
* __register_sysctl_table - register a leaf sysctl table
* @set: Sysctl tree to register on
* @path: The path to the directory the sysctl table is in.
- * @table: the top-level table structure
+ *
+ * @table: the top-level table structure. This table 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.
+ * array.
*
* The members of the &struct ctl_table structure are used as follows:
- *
* procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
* enter a sysctl file
- *
- * data - a pointer to data for use by proc_handler
- *
- * maxlen - the maximum size in bytes of the data
- *
- * mode - the file permissions for the /proc/sys file
- *
- * child - must be %NULL.
- *
+ * data - a pointer to data for use by proc_handler
+ * maxlen - the maximum size in bytes of the data
+ * mode - the file permissions for the /proc/sys file
+ * type - Defines the target type (described in struct definition)
* proc_handler - the text handler routine (described below)
*
* extra1, extra2 - extra pointers usable by the proc handler routines
+ * XXX: we should eventually modify these to use long min / max [0]
+ * [0] https://lkml.kernel.org/87zgpte9o4.fsf@email.froward.int.ebiederm.org
*
* Leaf nodes in the sysctl tree will be represented by a single file
- * under /proc; non-leaf nodes will be represented by directories.
+ * under /proc; non-leaf nodes are not allowed.
*
* There must be a proc_handler routine for any terminal nodes.
* Several default handlers are available to cover common cases -
@@ -1298,53 +1369,32 @@ out:
*/
struct ctl_table_header *__register_sysctl_table(
struct ctl_table_set *set,
- const char *path, struct ctl_table *table)
+ const char *path, const struct ctl_table *table, size_t table_size)
{
struct ctl_table_root *root = set->dir.header.root;
struct ctl_table_header *header;
- const char *name, *nextname;
struct ctl_dir *dir;
- struct ctl_table *entry;
struct ctl_node *node;
- int nr_entries = 0;
-
- for (entry = table; entry->procname; entry++)
- nr_entries++;
header = kzalloc(sizeof(struct ctl_table_header) +
- sizeof(struct ctl_node)*nr_entries, GFP_KERNEL);
+ 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);
dir = &set->dir;
- /* Reference moved down the diretory tree get_subdir */
+ /* Reference moved down the directory tree get_subdir */
dir->header.nreg++;
spin_unlock(&sysctl_lock);
- /* Find the directory for the ctl_table */
- for (name = path; name; name = nextname) {
- int namelen;
- nextname = strchr(name, '/');
- if (nextname) {
- namelen = nextname - name;
- nextname++;
- } else {
- namelen = strlen(name);
- }
- if (namelen == 0)
- continue;
-
- dir = get_subdir(dir, name, namelen);
- if (IS_ERR(dir))
- goto fail;
- }
-
+ dir = sysctl_mkdir_p(dir, path);
+ if (IS_ERR(dir))
+ goto fail;
spin_lock(&sysctl_lock);
if (insert_header(dir, header))
goto fail_put_dir_locked;
@@ -1359,247 +1409,75 @@ fail_put_dir_locked:
spin_unlock(&sysctl_lock);
fail:
kfree(header);
- dump_stack();
return NULL;
}
/**
- * register_sysctl - register a sysctl table
- * @path: The path to the directory the sysctl table is in.
- * @table: the table structure
+ * 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
+ * will be kept during the lifetime use of the syctl. It must not be freed
+ * until unregister_sysctl_table() is called with the given returned table
+ * with this registration. If your code is non modular then you don't need
+ * 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, const struct ctl_table *table,
+ size_t table_size)
{
return __register_sysctl_table(&sysctl_table_root.default_set,
- path, table);
-}
-EXPORT_SYMBOL(register_sysctl);
-
-static char *append_path(const char *path, char *pos, const char *name)
-{
- int namelen;
- namelen = strlen(name);
- if (((pos - path) + namelen + 2) >= PATH_MAX)
- return NULL;
- memcpy(pos, name, namelen);
- pos[namelen] = '/';
- pos[namelen + 1] = '\0';
- pos += namelen + 1;
- return pos;
-}
-
-static int count_subheaders(struct ctl_table *table)
-{
- int has_files = 0;
- int nr_subheaders = 0;
- struct ctl_table *entry;
-
- /* special case: no directory and empty directory */
- if (!table || !table->procname)
- return 1;
-
- for (entry = table; entry->procname; entry++) {
- if (entry->child)
- nr_subheaders += count_subheaders(entry->child);
- else
- has_files = 1;
- }
- return nr_subheaders + has_files;
-}
-
-static int register_leaf_sysctl_tables(const char *path, char *pos,
- struct ctl_table_header ***subheader, struct ctl_table_set *set,
- struct ctl_table *table)
-{
- struct ctl_table *ctl_table_arg = NULL;
- struct ctl_table *entry, *files;
- int nr_files = 0;
- int nr_dirs = 0;
- int err = -ENOMEM;
-
- for (entry = table; entry->procname; entry++) {
- if (entry->child)
- nr_dirs++;
- else
- nr_files++;
- }
-
- files = table;
- /* If there are mixed files and directories we need a new table */
- if (nr_dirs && nr_files) {
- struct ctl_table *new;
- files = kcalloc(nr_files + 1, sizeof(struct ctl_table),
- GFP_KERNEL);
- if (!files)
- goto out;
-
- ctl_table_arg = files;
- for (new = files, entry = table; entry->procname; entry++) {
- if (entry->child)
- continue;
- *new = *entry;
- new++;
- }
- }
-
- /* Register everything except a directory full of subdirectories */
- if (nr_files || !nr_dirs) {
- struct ctl_table_header *header;
- header = __register_sysctl_table(set, path, files);
- if (!header) {
- kfree(ctl_table_arg);
- goto out;
- }
-
- /* Remember if we need to free the file table */
- header->ctl_table_arg = ctl_table_arg;
- **subheader = header;
- (*subheader)++;
- }
-
- /* Recurse into the subdirectories. */
- for (entry = table; entry->procname; entry++) {
- char *child_pos;
-
- if (!entry->child)
- continue;
-
- err = -ENAMETOOLONG;
- child_pos = append_path(path, pos, entry->procname);
- if (!child_pos)
- goto out;
-
- err = register_leaf_sysctl_tables(path, child_pos, subheader,
- set, entry->child);
- pos[0] = '\0';
- if (err)
- goto out;
- }
- err = 0;
-out:
- /* On failure our caller will unregister all registered subheaders */
- return err;
+ path, table, table_size);
}
+EXPORT_SYMBOL(register_sysctl_sz);
/**
- * __register_sysctl_paths - register a sysctl table hierarchy
- * @set: Sysctl tree to register on
- * @path: The path to the directory the sysctl table is in.
- * @table: the top-level table structure
+ * __register_sysctl_init() - register sysctl table to path
+ * @path: path name for sysctl base. If that path doesn't exist we will create
+ * it for you.
+ * @table: This is the sysctl table that needs to be registered to the path.
+ * The caller must ensure the life of the @table will be kept during the
+ * 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
*
- * Register a sysctl table hierarchy. @table should be a filled in ctl_table
- * array. A completely 0 filled entry terminates the 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
+ * values pre-set. Code which depends on these variables will always work even
+ * if register_sysctl() fails. If register_sysctl() fails you'd just loose the
+ * ability to query or modify the sysctls dynamically at run time. Chances of
+ * register_sysctl() failing on init are extremely low, and so for both reasons
+ * this function does not return any error as it is used by initialization code.
*
- * See __register_sysctl_table for more details.
+ * Context: if your base directory does not exist it will be created for you.
*/
-struct ctl_table_header *__register_sysctl_paths(
- struct ctl_table_set *set,
- const struct ctl_path *path, struct ctl_table *table)
+void __init __register_sysctl_init(const char *path, const struct ctl_table *table,
+ const char *table_name, size_t table_size)
{
- struct ctl_table *ctl_table_arg = table;
- int nr_subheaders = count_subheaders(table);
- struct ctl_table_header *header = NULL, **subheaders, **subheader;
- const struct ctl_path *component;
- char *new_path, *pos;
-
- pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL);
- if (!new_path)
- return NULL;
-
- pos[0] = '\0';
- for (component = path; component->procname; component++) {
- pos = append_path(new_path, pos, component->procname);
- if (!pos)
- goto out;
- }
- while (table->procname && table->child && !table[1].procname) {
- pos = append_path(new_path, pos, table->procname);
- if (!pos)
- goto out;
- table = table->child;
- }
- if (nr_subheaders == 1) {
- header = __register_sysctl_table(set, new_path, table);
- if (header)
- header->ctl_table_arg = ctl_table_arg;
- } else {
- header = kzalloc(sizeof(*header) +
- sizeof(*subheaders)*nr_subheaders, GFP_KERNEL);
- if (!header)
- goto out;
+ struct ctl_table_header *hdr = register_sysctl_sz(path, table, table_size);
- subheaders = (struct ctl_table_header **) (header + 1);
- subheader = subheaders;
- header->ctl_table_arg = ctl_table_arg;
-
- if (register_leaf_sysctl_tables(new_path, pos, &subheader,
- set, table))
- goto err_register_leaves;
- }
-
-out:
- kfree(new_path);
- return header;
-
-err_register_leaves:
- while (subheader > subheaders) {
- struct ctl_table_header *subh = *(--subheader);
- struct ctl_table *table = subh->ctl_table_arg;
- unregister_sysctl_table(subh);
- kfree(table);
+ if (unlikely(!hdr)) {
+ pr_err("failed when register_sysctl_sz %s to %s\n", table_name, path);
+ return;
}
- kfree(header);
- header = NULL;
- goto out;
+ kmemleak_not_leak(hdr);
}
-/**
- * register_sysctl_table_path - register a sysctl table hierarchy
- * @path: The path to the directory the sysctl table is in.
- * @table: the top-level table structure
- *
- * Register a sysctl table hierarchy. @table should be a filled in ctl_table
- * array. A completely 0 filled entry terminates the table.
- *
- * See __register_sysctl_paths for more details.
- */
-struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
- struct ctl_table *table)
-{
- return __register_sysctl_paths(&sysctl_table_root.default_set,
- path, table);
-}
-EXPORT_SYMBOL(register_sysctl_paths);
-
-/**
- * register_sysctl_table - register a sysctl table hierarchy
- * @table: the top-level table structure
- *
- * Register a sysctl table hierarchy. @table should be a filled in ctl_table
- * array. A completely 0 filled entry terminates the table.
- *
- * See register_sysctl_paths for more details.
- */
-struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
-{
- static const struct ctl_path null_path[] = { {} };
-
- return register_sysctl_paths(null_path, table);
-}
-EXPORT_SYMBOL(register_sysctl_table);
-
static void put_links(struct ctl_table_header *header)
{
struct ctl_table_set *root_set = &sysctl_table_root.default_set;
struct ctl_table_root *root = header->root;
struct ctl_dir *parent = header->parent;
struct ctl_dir *core_parent;
- struct ctl_table *entry;
+ const struct ctl_table *entry;
if (header->set == root_set)
return;
@@ -1608,9 +1486,9 @@ static void put_links(struct ctl_table_header *header)
if (IS_ERR(core_parent))
return;
- for (entry = header->ctl_table; entry->procname; entry++) {
+ list_for_each_table_entry(entry, header) {
struct ctl_table_header *link_head;
- struct ctl_table *link;
+ const struct ctl_table *link;
const char *name = entry->procname;
link = find_entry(&link_head, core_parent, name, strlen(name));
@@ -1622,7 +1500,7 @@ static void put_links(struct ctl_table_header *header)
else {
pr_err("sysctl link missing during unregister: ");
sysctl_print_dir(parent);
- pr_cont("/%s\n", name);
+ pr_cont("%s\n", name);
}
}
}
@@ -1648,35 +1526,18 @@ static void drop_sysctl_table(struct ctl_table_header *header)
/**
* unregister_sysctl_table - unregister a sysctl table hierarchy
- * @header: the header returned from register_sysctl_table
+ * @header: the header returned from register_sysctl or __register_sysctl_table
*
* Unregisters the sysctl table and all children. proc entries may not
* actually be removed until they are no longer used by anyone.
*/
void unregister_sysctl_table(struct ctl_table_header * header)
{
- int nr_subheaders;
might_sleep();
if (header == NULL)
return;
- nr_subheaders = count_subheaders(header->ctl_table_arg);
- if (unlikely(nr_subheaders > 1)) {
- struct ctl_table_header **subheaders;
- int i;
-
- subheaders = (struct ctl_table_header **)(header + 1);
- for (i = nr_subheaders -1; i >= 0; i--) {
- struct ctl_table_header *subh = subheaders[i];
- struct ctl_table *table = subh->ctl_table_arg;
- unregister_sysctl_table(subh);
- kfree(table);
- }
- kfree(header);
- return;
- }
-
spin_lock(&sysctl_lock);
drop_sysctl_table(header);
spin_unlock(&sysctl_lock);
@@ -1689,7 +1550,7 @@ 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)
@@ -1706,7 +1567,7 @@ int __init proc_sys_init(void)
proc_sys_root->proc_dir_ops = &proc_sys_dir_file_operations;
proc_sys_root->nlink = 0;
- return sysctl_init();
+ return sysctl_init_bases();
}
struct sysctl_alias {
@@ -1728,7 +1589,6 @@ static const struct sysctl_alias sysctl_aliases[] = {
{"hung_task_panic", "kernel.hung_task_panic" },
{"numa_zonelist_order", "vm.numa_zonelist_order" },
{"softlockup_all_cpu_backtrace", "kernel.softlockup_all_cpu_backtrace" },
- {"softlockup_panic", "kernel.softlockup_panic" },
{ }
};
@@ -1744,6 +1604,13 @@ static const char *sysctl_find_alias(char *param)
return NULL;
}
+bool sysctl_is_alias(char *param)
+{
+ const char *alias = sysctl_find_alias(param);
+
+ return alias != NULL;
+}
+
/* Set sysctl value passed on kernel command line. */
static int process_sysctl_arg(char *param, char *val,
const char *unused, void *arg)
@@ -1770,6 +1637,12 @@ static int process_sysctl_arg(char *param, char *val,
return 0;
}
+ if (!val)
+ return -EINVAL;
+ len = strlen(val);
+ if (len == 0)
+ return -EINVAL;
+
/*
* To set sysctl options, we use a temporary mount of proc, look up the
* respective sys/ file and write to it. To avoid mounting it when no
@@ -1797,7 +1670,7 @@ static int process_sysctl_arg(char *param, char *val,
panic("%s: Failed to allocate path for %s\n", __func__, param);
strreplace(path, '.', '/');
- file = file_open_root((*proc_mnt)->mnt_root, *proc_mnt, path, O_WRONLY, 0);
+ file = file_open_root_mnt(*proc_mnt, path, O_WRONLY, 0);
if (IS_ERR(file)) {
err = PTR_ERR(file);
if (err == -ENOENT)
@@ -1811,7 +1684,6 @@ static int process_sysctl_arg(char *param, char *val,
file, param, val);
goto out;
}
- len = strlen(val);
wret = kernel_write(file, val, len, &pos);
if (wret < 0) {
err = wret;
generated by cgit (git 2.34.1) at 2025-12-25 10:16:44 +0000