[PATCH v2 01/14] sysctl: Prefer ctl_table_header in proc_sysctl

Joel Granados
2023-07-31T07:19:41Z

This is a preparation commit that replaces ctl_table with
ctl_table_header as the pointer that is passed around in proc_sysctl.c.
This will become necessary in subsequent commits when the size of the
ctl_table array can no longer be calculated by searching for an empty
sentinel (last empty ctl_table element) but will be carried along inside
the ctl_table_header struct.

Signed-off-by: Joel Granados <j.granados@samsung.com>
---
fs/proc/proc_sysctl.c | 36 ++++++++++++++++++------------------
1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 5ea42653126e..94d71446da39 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -1125,11 +1125,11 @@ 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->ctl_table) {
if ((entry->proc_handler == proc_dostring) ||
(entry->proc_handler == proc_dobool) ||
(entry->proc_handler == proc_dointvec) ||
@@ -1159,8 +1159,7 @@ 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 +1169,7 @@ 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->ctl_table) {
nr_entries++;
name_bytes += strlen(entry->procname) + 1;
}
@@ -1189,12 +1188,12 @@ 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->ctl_table) {
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++;
}
@@ -1205,15 +1204,16 @@ static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table
}

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->ctl_table) {
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 +1224,10 @@ 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->ctl_table) {
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 +1246,13 @@ 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 +1260,7 @@ 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;
}
@@ -1371,7 +1371,7 @@ struct ctl_table_header *__register_sysctl_table(

node = (struct ctl_node *)(header + 1);
init_header(header, root, set, node, table);
- if (sysctl_check_table(path, table))
+ if (sysctl_check_table(path, header))
goto fail;

spin_lock(&sysctl_lock);
--
2.30.2