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authorLinus Torvalds <torvalds@linux-foundation.org>2023-06-29 02:05:21 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-06-29 02:05:21 +0300
commit6a8cbd9253abc1bd0df4d60c4c24fa555190376d (patch)
tree76f3ef8bde90d9aa4c2f1a17835641b58637ed7b /fs/proc
parent4e3c09e95499e83dafc93860d56070a76d20e830 (diff)
parent2f2665c13af4895b26761107c2f637c2f112d8e9 (diff)
downloadlinux-6a8cbd9253abc1bd0df4d60c4c24fa555190376d.tar.xz
Merge tag 'v6.5-rc1-sysctl-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull sysctl updates from Luis Chamberlain: "The changes for sysctl are in line with prior efforts to stop usage of deprecated routines which incur recursion and also make it hard to remove the empty array element in each sysctl array declaration. The most difficult user to modify was parport which required a bit of re-thinking of how to declare shared sysctls there, Joel Granados has stepped up to the plate to do most of this work and eventual removal of register_sysctl_table(). That work ended up saving us about 1465 bytes according to bloat-o-meter. Since we gained a few bloat-o-meter karma points I moved two rather small sysctl arrays from kernel/sysctl.c leaving us only two more sysctl arrays to move left. Most changes have been tested on linux-next for about a month. The last straggler patches are a minor parport fix, changes to the sysctl kernel selftest so to verify correctness and prevent regressions for the future change he made to provide an alternative solution for the special sysctl mount point target which was using the now deprecated sysctl child element. This is all prep work to now finally be able to remove the empty array element in all sysctl declarations / registrations which is expected to save us a bit of bytes all over the kernel. That work will be tested early after v6.5-rc1 is out" * tag 'v6.5-rc1-sysctl-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: sysctl: replace child with an enumeration sysctl: Remove debugging dump_stack test_sysclt: Test for registering a mount point test_sysctl: Add an option to prevent test skip test_sysctl: Add an unregister sysctl test test_sysctl: Group node sysctl test under one func test_sysctl: Fix test metadata getters parport: plug a sysctl register leak sysctl: move security keys sysctl registration to its own file sysctl: move umh sysctl registration to its own file signal: move show_unhandled_signals sysctl to its own file sysctl: remove empty dev table sysctl: Remove register_sysctl_table sysctl: Refactor base paths registrations sysctl: stop exporting register_sysctl_table parport: Removed sysctl related defines parport: Remove register_sysctl_table from parport_default_proc_register parport: Remove register_sysctl_table from parport_device_proc_register parport: Remove register_sysctl_table from parport_proc_register parport: Move magic number "15" to a define
Diffstat (limited to 'fs/proc')
-rw-r--r--fs/proc/proc_sysctl.c244
1 files changed, 19 insertions, 225 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index ae832e982003..4e5488975415 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -29,9 +29,8 @@ static const struct file_operations proc_sys_dir_file_operations;
static const struct inode_operations proc_sys_dir_operations;
/* Support for permanently empty directories */
-
struct ctl_table sysctl_mount_point[] = {
- { }
+ {.type = SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY }
};
/**
@@ -48,21 +47,14 @@ struct ctl_table_header *register_sysctl_mount_point(const char *path)
}
EXPORT_SYMBOL(register_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)
-{
- dir->header.ctl_table[0].child = 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_table(tptr) \
+ (tptr[0].type == SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY)
+#define sysctl_is_perm_empty_ctl_header(hptr) \
+ (sysctl_is_perm_empty_ctl_table(hptr->ctl_table))
+#define sysctl_set_perm_empty_ctl_header(hptr) \
+ (hptr->ctl_table[0].type = SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY)
+#define sysctl_clear_perm_empty_ctl_header(hptr) \
+ (hptr->ctl_table[0].type = SYSCTL_TABLE_TYPE_DEFAULT)
void proc_sys_poll_notify(struct ctl_table_poll *poll)
{
@@ -230,20 +222,22 @@ static void erase_header(struct ctl_table_header *head)
static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header)
{
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_table(header->ctl_table)) {
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)
@@ -259,9 +253,9 @@ 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;
}
@@ -479,7 +473,7 @@ 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);
}
@@ -1136,9 +1130,6 @@ static int sysctl_check_table(const char *path, struct ctl_table *table)
struct ctl_table *entry;
int err = 0;
list_for_each_table_entry(entry, table) {
- if (entry->child)
- err |= sysctl_err(path, entry, "Not a file");
-
if ((entry->proc_handler == proc_dostring) ||
(entry->proc_handler == proc_dobool) ||
(entry->proc_handler == proc_dointvec) ||
@@ -1406,7 +1397,6 @@ fail_put_dir_locked:
spin_unlock(&sysctl_lock);
fail:
kfree(header);
- dump_stack();
return NULL;
}
@@ -1466,185 +1456,6 @@ void __init __register_sysctl_init(const char *path, struct ctl_table *table,
kmemleak_not_leak(hdr);
}
-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;
-
- list_for_each_table_entry(entry, table) {
- 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;
-
- list_for_each_table_entry(entry, table) {
- 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;
- new = files;
-
- list_for_each_table_entry(entry, table) {
- 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. */
- list_for_each_table_entry(entry, table) {
- 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;
-}
-
-/**
- * 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.
- * We are slowly deprecating this call so avoid its use.
- */
-struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
-{
- struct ctl_table *ctl_table_arg = table;
- int nr_subheaders = count_subheaders(table);
- struct ctl_table_header *header = NULL, **subheaders, **subheader;
- char *new_path, *pos;
-
- pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL);
- if (!new_path)
- return NULL;
-
- pos[0] = '\0';
- 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(&sysctl_table_root.default_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;
-
- 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,
- &sysctl_table_root.default_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);
- }
- kfree(header);
- header = NULL;
- goto out;
-}
-EXPORT_SYMBOL(register_sysctl_table);
-
-int __register_sysctl_base(struct ctl_table *base_table)
-{
- struct ctl_table_header *hdr;
-
- hdr = register_sysctl_table(base_table);
- kmemleak_not_leak(hdr);
- return 0;
-}
-
static void put_links(struct ctl_table_header *header)
{
struct ctl_table_set *root_set = &sysctl_table_root.default_set;
@@ -1700,35 +1511,18 @@ 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);