From: "Thomas Weißschuh" <linux@weissschuh.net>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@fomichev.me>,
Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>,
Luis Chamberlain <mcgrof@kernel.org>,
Kees Cook <kees@kernel.org>,
Joel Granados <j.granados@samsung.com>
Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org,
"Thomas Weißschuh" <linux@weissschuh.net>
Subject: [PATCH v2 3/6] sysctl: move internal interfaces to const struct ctl_table
Date: Mon, 05 Aug 2024 11:39:37 +0200 [thread overview]
Message-ID: <20240805-sysctl-const-api-v2-3-52c85f02ee5e@weissschuh.net> (raw)
In-Reply-To: <20240805-sysctl-const-api-v2-0-52c85f02ee5e@weissschuh.net>
As a preparation to make all the core sysctl code work with const struct
ctl_table switch over the internal function to use the const variant.
Some pointers to "struct ctl_table" need to stay non-const as they are
newly allocated and modified before registration.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
fs/proc/internal.h | 2 +-
fs/proc/proc_sysctl.c | 81 +++++++++++++++++++++++++-------------------------
include/linux/sysctl.h | 2 +-
3 files changed, 43 insertions(+), 42 deletions(-)
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index a8a8576d8592..fcab5dd7ddb1 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -102,7 +102,7 @@ struct proc_inode {
union proc_op op;
struct proc_dir_entry *pde;
struct ctl_table_header *sysctl;
- struct ctl_table *sysctl_entry;
+ const struct ctl_table *sysctl_entry;
struct hlist_node sibling_inodes;
const struct proc_ns_operations *ns_ops;
struct inode vfs_inode;
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index d11ebc055ce0..713abccbfcf9 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -88,7 +88,7 @@ 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);
@@ -110,11 +110,11 @@ static int namecmp(const char *name1, int len1, const char *name2, int len2)
}
/* 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;
while (node)
@@ -141,7 +141,7 @@ 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;
@@ -151,7 +151,7 @@ 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;
@@ -180,7 +180,7 @@ 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;
@@ -189,7 +189,7 @@ 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, size_t table_size)
+ struct ctl_node *node, const struct ctl_table *table, size_t table_size)
{
head->ctl_table = table;
head->ctl_table_size = table_size;
@@ -204,7 +204,7 @@ static void init_header(struct ctl_table_header *head,
head->node = node;
INIT_HLIST_HEAD(&head->inodes);
if (node) {
- struct ctl_table *entry;
+ const struct ctl_table *entry;
list_for_each_table_entry(entry, head) {
node->header = head;
@@ -217,7 +217,7 @@ static void init_header(struct ctl_table_header *head,
static void erase_header(struct ctl_table_header *head)
{
- struct ctl_table *entry;
+ const struct ctl_table *entry;
list_for_each_table_entry(entry, head)
erase_entry(head, entry);
@@ -225,7 +225,7 @@ 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;
+ const struct ctl_table *entry;
struct ctl_table_header *dir_h = &dir->header;
int err;
@@ -344,12 +344,12 @@ 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);
@@ -374,10 +374,10 @@ 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);
@@ -391,10 +391,10 @@ 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);
@@ -427,7 +427,7 @@ 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;
@@ -441,7 +441,7 @@ 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;
@@ -512,7 +512,7 @@ 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;
@@ -550,7 +550,7 @@ static ssize_t proc_sys_call_handler(struct kiocb *iocb, struct iov_iter *iter,
{
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;
+ const struct ctl_table *table = PROC_I(inode)->sysctl_entry;
size_t count = iov_iter_count(iter);
char *kbuf;
ssize_t error;
@@ -624,7 +624,7 @@ static ssize_t proc_sys_write(struct kiocb *iocb, struct iov_iter *iter)
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))
@@ -642,7 +642,7 @@ 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;
@@ -673,7 +673,7 @@ static __poll_t proc_sys_poll(struct file *filp, poll_table *wait)
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;
@@ -717,7 +717,7 @@ 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;
@@ -735,7 +735,7 @@ static bool proc_sys_link_fill_cache(struct file *file,
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)
{
@@ -759,7 +759,7 @@ 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;
@@ -792,7 +792,7 @@ static int proc_sys_permission(struct mnt_idmap *idmap,
* 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/ */
@@ -836,7 +836,7 @@ static int proc_sys_getattr(struct mnt_idmap *idmap,
{
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);
@@ -935,7 +935,7 @@ 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)
@@ -1046,12 +1046,12 @@ 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;
@@ -1078,7 +1078,7 @@ 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;
@@ -1094,7 +1094,7 @@ 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;
@@ -1133,7 +1133,7 @@ static int sysctl_check_table_array(const char *path, struct ctl_table *table)
static int sysctl_check_table(const char *path, struct ctl_table_header *header)
{
- struct ctl_table *entry;
+ const struct ctl_table *entry;
int err = 0;
list_for_each_table_entry(entry, header) {
if (!entry->procname)
@@ -1169,8 +1169,9 @@ static int sysctl_check_table(const char *path, struct ctl_table_header *header)
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 name_bytes;
@@ -1215,7 +1216,7 @@ static bool get_links(struct ctl_dir *dir,
struct ctl_table_root *link_root)
{
struct ctl_table_header *tmp_head;
- struct ctl_table *entry, *link;
+ const struct ctl_table *entry, *link;
if (header->ctl_table_size == 0 ||
sysctl_is_perm_empty_ctl_header(header))
@@ -1466,7 +1467,7 @@ static void put_links(struct ctl_table_header *header)
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;
@@ -1477,7 +1478,7 @@ static void put_links(struct ctl_table_header *header)
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));
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index aa4c6d44aaa0..a473deaf5a91 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -162,7 +162,7 @@ struct ctl_node {
struct ctl_table_header {
union {
struct {
- struct ctl_table *ctl_table;
+ const struct ctl_table *ctl_table;
int ctl_table_size;
int used;
int count;
--
2.46.0
next prev parent reply other threads:[~2024-08-05 9:40 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-05 9:39 [PATCH v2 0/6] sysctl: prepare sysctl core for const struct ctl_table Thomas Weißschuh
2024-08-05 9:39 ` [PATCH v2 1/6] sysctl: avoid spurious permanent empty tables Thomas Weißschuh
2024-08-24 18:05 ` Thomas Weißschuh
2024-09-02 9:19 ` Joel Granados
2024-08-05 9:39 ` [PATCH v2 2/6] bpf: Constify ctl_table argument of filter function Thomas Weißschuh
2024-08-05 9:39 ` Thomas Weißschuh [this message]
2024-08-05 9:39 ` [PATCH v2 4/6] sysctl: allow registration of const struct ctl_table Thomas Weißschuh
2024-08-05 9:39 ` [PATCH v2 5/6] sysctl: make internal ctl_tables const Thomas Weißschuh
2024-08-05 9:39 ` [PATCH v2 6/6] const_structs.checkpatch: add ctl_table Thomas Weißschuh
2024-10-09 11:56 ` [PATCH v2 0/6] sysctl: prepare sysctl core for const struct ctl_table Joel Granados
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