procfs: make freeing proc_fs_info rcu-delayed

makes proc_pid_ns() safe from rcu pathwalk (put_pid_ns()
is still synchronous, but that's not a problem - it does
rcu-delay everything that needs to be)

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2023-09-20 00:12:00 -04:00
parent 47458802f6
commit e31f0a57ae
2 changed files with 2 additions and 1 deletions

View File

@ -271,7 +271,7 @@ static void proc_kill_sb(struct super_block *sb)
kill_anon_super(sb);
put_pid_ns(fs_info->pid_ns);
kfree(fs_info);
kfree_rcu(fs_info, rcu);
}
static struct file_system_type proc_fs_type = {

View File

@ -65,6 +65,7 @@ struct proc_fs_info {
kgid_t pid_gid;
enum proc_hidepid hide_pid;
enum proc_pidonly pidonly;
struct rcu_head rcu;
};
static inline struct proc_fs_info *proc_sb_info(struct super_block *sb)