1 // SPDX-License-Identifier: GPL-2.0
27  * pidfd_show_fdinfo - print information about a pidfd
53  * - create two new pid namespaces ns1 and ns2 in the initial pid
56  * - create a process with a pidfd in ns1
57  * - send pidfd from ns1 to ns2
58  * - read /proc/self/fdinfo/<pidfd> and observe that both Pid and NSpid
65 	pid_t nr = -1;  in pidfd_show_fdinfo()
68 		ns = proc_pid_ns(file_inode(m->file)->i_sb);  in pidfd_show_fdinfo()
79 		/* If nr is non-zero it means that 'pid' is valid and that  in pidfd_show_fdinfo()
84 		for (i = ns->level + 1; i <= pid->level; i++)  in pidfd_show_fdinfo()
85 			seq_put_decimal_ll(m, "\t", pid->numbers[i].nr);  in pidfd_show_fdinfo()
98 	bool thread = file->f_flags & PIDFD_THREAD;  in pidfd_poll()
102 	poll_wait(file, &pid->wait_pidfd, pts);  in pidfd_poll()
105 	 * or the whole thread-group exits.  in pidfd_poll()
111 	else if (task->exit_state && (thread || thread_group_empty(task)))  in pidfd_poll()
126 		return -EINVAL;  in pidfd_ioctl()
130 		return -ESRCH;  in pidfd_ioctl()
133 		nsp = task->nsproxy;  in pidfd_ioctl()
138 		return -ESRCH; /* just pretend it didn't exist */  in pidfd_ioctl()
145 		return -EACCES;  in pidfd_ioctl()
151 			get_cgroup_ns(nsp->cgroup_ns);  in pidfd_ioctl()
152 			ns_common = to_ns_common(nsp->cgroup_ns);  in pidfd_ioctl()
157 			get_ipc_ns(nsp->ipc_ns);  in pidfd_ioctl()
158 			ns_common = to_ns_common(nsp->ipc_ns);  in pidfd_ioctl()
162 		get_mnt_ns(nsp->mnt_ns);  in pidfd_ioctl()
163 		ns_common = to_ns_common(nsp->mnt_ns);  in pidfd_ioctl()
167 			ns_common = to_ns_common(nsp->net_ns);  in pidfd_ioctl()
173 			get_pid_ns(nsp->pid_ns_for_children);  in pidfd_ioctl()
174 			ns_common = to_ns_common(nsp->pid_ns_for_children);  in pidfd_ioctl()
179 			get_time_ns(nsp->time_ns);  in pidfd_ioctl()
180 			ns_common = to_ns_common(nsp->time_ns);  in pidfd_ioctl()
185 			get_time_ns(nsp->time_ns_for_children);  in pidfd_ioctl()
186 			ns_common = to_ns_common(nsp->time_ns_for_children);  in pidfd_ioctl()
191 			get_uts_ns(nsp->uts_ns);  in pidfd_ioctl()
192 			ns_common = to_ns_common(nsp->uts_ns);  in pidfd_ioctl()
213 		return -ENOIOCTLCMD;  in pidfd_ioctl()
217 		return -EOPNOTSUPP;  in pidfd_ioctl()
234 	if (file->f_op != &pidfs_file_operations)  in pidfd_pid()
235 		return ERR_PTR(-EBADF);  in pidfd_pid()
236 	return file_inode(file)->i_private;  in pidfd_pid()
243  * Provide a fallback mechanism for 32-bit systems so processes remain
255 		return -ENOSPC;  in pidfs_inum()
269 	*ino = pid->ino;  in pidfs_inum()
276  * The vfs falls back to simple_setattr() if i_op->setattr() isn't
283 	return -EOPNOTSUPP;  in pidfs_setattr()
288  * User space expects pidfs inodes to have no file type in st_mode.
292  *	type = s->st_mode & S_IFMT;
297  *			Lf->ntype = Ntype = N_ANON_INODE;
308 	struct inode *inode = d_inode(path->dentry);  in pidfs_getattr()
311 	stat->mode &= ~S_IFMT;  in pidfs_getattr()
322 	struct pid *pid = inode->i_private;  in pidfs_evict_inode()
326 	pidfs_free_inum(inode->i_ino);  in pidfs_evict_inode()
352 	inode->i_private = data;  in pidfs_init_inode()
353 	inode->i_flags |= S_PRIVATE;  in pidfs_init_inode()
354 	inode->i_mode |= S_IRWXU;  in pidfs_init_inode()
355 	inode->i_op = &pidfs_inode_operations;  in pidfs_init_inode()
356 	inode->i_fop = &pidfs_file_operations;  in pidfs_init_inode()
358 	 * Inode numbering for pidfs start at RESERVED_PIDS + 1. This  in pidfs_init_inode()
362 	return pidfs_inum(data, &inode->i_ino);  in pidfs_init_inode()
382 		return -ENOMEM;  in pidfs_init_fs_context()
384 	ctx->ops = &pidfs_sops;  in pidfs_init_fs_context()
385 	ctx->dops = &pidfs_dentry_operations;  in pidfs_init_fs_context()
386 	fc->s_fs_info = (void *)&pidfs_stashed_ops;  in pidfs_init_fs_context()
403 	ret = path_from_stashed(&pid->stashed, pidfs_mnt, get_pid(pid), &path);  in pidfs_alloc_file()