Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) #include <linux/cache.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) #include <linux/pid_namespace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) #include "internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  * /proc/thread_self:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) static const char *proc_thread_self_get_link(struct dentry *dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 					     struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 					     struct delayed_call *done)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 	struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 	pid_t tgid = task_tgid_nr_ns(current, ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 	pid_t pid = task_pid_nr_ns(current, ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	 * Not currently supported. Once we can inherit all of struct pid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	 * we can allow this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	if (current->flags & PF_IO_WORKER)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 		return ERR_PTR(-EOPNOTSUPP);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	if (!pid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 		return ERR_PTR(-ENOENT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	name = kmalloc(10 + 6 + 10 + 1, dentry ? GFP_KERNEL : GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	if (unlikely(!name))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 		return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	sprintf(name, "%u/task/%u", tgid, pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	set_delayed_call(done, kfree_link, name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	return name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static const struct inode_operations proc_thread_self_inode_operations = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	.get_link	= proc_thread_self_get_link,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) static unsigned thread_self_inum __ro_after_init;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) int proc_setup_thread_self(struct super_block *s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	struct inode *root_inode = d_inode(s->s_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	struct proc_fs_info *fs_info = proc_sb_info(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	struct dentry *thread_self;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 	int ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 	inode_lock(root_inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	thread_self = d_alloc_name(s->s_root, "thread-self");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 	if (thread_self) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 		struct inode *inode = new_inode(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 		if (inode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 			inode->i_ino = thread_self_inum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 			inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 			inode->i_mode = S_IFLNK | S_IRWXUGO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 			inode->i_uid = GLOBAL_ROOT_UID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 			inode->i_gid = GLOBAL_ROOT_GID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 			inode->i_op = &proc_thread_self_inode_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 			d_add(thread_self, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 			ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 			dput(thread_self);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 	inode_unlock(root_inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 		pr_err("proc_fill_super: can't allocate /proc/thread-self\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 		fs_info->proc_thread_self = thread_self;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) void __init proc_thread_self_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) 	proc_alloc_inum(&thread_self_inum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) }