[PATCH] lsm: constify 'sb' parameter in security_sb_kern_mount()

[Khadija Kamran]

The "sb_kern_mount" hook has implementation registered in SELinux.
Looking at the function implementation we observe that the "sb"
parameter is not changing.

Mark the "sb" parameter of LSM hook security_sb_kern_mount() as "const"
since it will not be changing in the LSM hook.

Signed-off-by: Khadija Kamran <kamrankhadijadj at gmail.com>
---
 include/linux/lsm_hook_defs.h | 2 +-
 include/linux/security.h      | 2 +-
 security/security.c           | 2 +-
 security/selinux/hooks.c      | 4 ++--
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 6bb55e61e8e8..f38491b77616 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -65,7 +65,7 @@ LSM_HOOK(void, LSM_RET_VOID, sb_free_mnt_opts, void *mnt_opts)
 LSM_HOOK(int, 0, sb_eat_lsm_opts, char *orig, void **mnt_opts)
 LSM_HOOK(int, 0, sb_mnt_opts_compat, struct super_block *sb, void *mnt_opts)
 LSM_HOOK(int, 0, sb_remount, struct super_block *sb, void *mnt_opts)
-LSM_HOOK(int, 0, sb_kern_mount, struct super_block *sb)
+LSM_HOOK(int, 0, sb_kern_mount, const struct super_block *sb)
 LSM_HOOK(int, 0, sb_show_options, struct seq_file *m, struct super_block *sb)
 LSM_HOOK(int, 0, sb_statfs, struct dentry *dentry)
 LSM_HOOK(int, 0, sb_mount, const char *dev_name, const struct path *path,
diff --git a/include/linux/security.h b/include/linux/security.h
index e2734e9e44d5..38f3ae6f25c2 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -302,7 +302,7 @@ void security_free_mnt_opts(void **mnt_opts);
 int security_sb_eat_lsm_opts(char *options, void **mnt_opts);
 int security_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts);
 int security_sb_remount(struct super_block *sb, void *mnt_opts);
-int security_sb_kern_mount(struct super_block *sb);
+int security_sb_kern_mount(const struct super_block *sb);
 int security_sb_show_options(struct seq_file *m, struct super_block *sb);
 int security_sb_statfs(struct dentry *dentry);
 int security_sb_mount(const char *dev_name, const struct path *path,
diff --git a/security/security.c b/security/security.c
index d5ff7ff45b77..5b21b4c61acb 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1304,7 +1304,7 @@ EXPORT_SYMBOL(security_sb_remount);
  *
  * Return: Returns 0 if permission is granted.
  */
-int security_sb_kern_mount(struct super_block *sb)
+int security_sb_kern_mount(const struct super_block *sb)
 {
 	return call_int_hook(sb_kern_mount, 0, sb);
 }
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 79b4890e9936..2708c5b5ecd7 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1886,7 +1886,7 @@ static inline int may_rename(struct inode *old_dir,
 
 /* Check whether a task can perform a filesystem operation. */
 static int superblock_has_perm(const struct cred *cred,
-			       struct super_block *sb,
+			       const struct super_block *sb,
 			       u32 perms,
 			       struct common_audit_data *ad)
 {
@@ -2670,7 +2670,7 @@ static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
 	return -EINVAL;
 }
 
-static int selinux_sb_kern_mount(struct super_block *sb)
+static int selinux_sb_kern_mount(const struct super_block *sb)
 {
 	const struct cred *cred = current_cred();
 	struct common_audit_data ad;
-- 
2.34.1