9 #include <linux/pid.h>
80 	struct pid *pid_a = rb_entry(a, struct pid, pidfs_node);  in pidfs_ino_cmp()
81 	struct pid *pid_b = rb_entry(b, struct pid, pidfs_node);  in pidfs_ino_cmp()
92 void pidfs_add_pid(struct pid *pid)  in pidfs_add_pid()  argument
98 	 * to struct pid is the inode number.  in pidfs_add_pid()
100 	 * On 32 bit the 64 bit number assigned to struct pid is split  in pidfs_add_pid()
124 	pid->ino = pidfs_ino_nr;  in pidfs_add_pid()
125 	pid->stashed = NULL;  in pidfs_add_pid()
129 	rb_find_add_rcu(&pid->pidfs_node, &pidfs_ino_tree, pidfs_ino_cmp);  in pidfs_add_pid()
133 void pidfs_remove_pid(struct pid *pid)  in pidfs_remove_pid()  argument
136 	rb_erase(&pid->pidfs_node, &pidfs_ino_tree);  in pidfs_remove_pid()
146  * Pid:
147  * This function will print the pid that a given pidfd refers to in the
148  * pid namespace of the procfs instance.
149  * If the pid namespace of the process is not a descendant of the pid
150  * namespace of the procfs instance 0 will be shown as its pid. This is
152  * its pid namespace.
155  * If pid namespaces are supported then this function will also print
156  * the pid of a given pidfd refers to for all descendant pid namespaces
157  * starting from the current pid namespace of the instance, i.e. the
158  * Pid field and the first entry in the NSpid field will be identical.
159  * If the pid namespace of the process is not a descendant of the pid
162  * Note that this differs from the Pid and NSpid fields in
163  * /proc/<pid>/status where Pid and NSpid are always shown relative to
164  * the  pid namespace of the procfs instance. The difference becomes
165  * obvious when sending around a pidfd between pid namespaces from a
167  * present between the pid namespaces:
168  * - create two new pid namespaces ns1 and ns2 in the initial pid
170  *   new pid namespace and mount procfs)
173  * - read /proc/self/fdinfo/<pidfd> and observe that both Pid and NSpid
178 	struct pid *pid = pidfd_pid(f);  in pidfd_show_fdinfo()  local
182 	if (likely(pid_has_task(pid, PIDTYPE_PID))) {  in pidfd_show_fdinfo()
184 		nr = pid_nr_ns(pid, ns);  in pidfd_show_fdinfo()
187 	seq_put_decimal_ll(m, "Pid:\t", nr);  in pidfd_show_fdinfo()
194 		/* If nr is non-zero it means that 'pid' is valid and that  in pidfd_show_fdinfo()
195 		 * ns, i.e. the pid namespace associated with the procfs  in pidfd_show_fdinfo()
196 		 * instance, is in the pid namespace hierarchy of pid.  in pidfd_show_fdinfo()
199 		for (i = ns->level + 1; i <= pid->level; i++)  in pidfd_show_fdinfo()
200 			seq_put_decimal_ll(m, "\t", pid->numbers[i].nr);  in pidfd_show_fdinfo()
212 	struct pid *pid = pidfd_pid(file);  in pidfd_poll()  local
216 	poll_wait(file, &pid->wait_pidfd, pts);  in pidfd_poll()
221 	 * and assumes the struct pid of the old thread-group leader.  in pidfd_poll()
224 	task = pid_task(pid, PIDTYPE_PID);  in pidfd_poll()
233 static inline bool pid_in_current_pidns(const struct pid *pid)  in pid_in_current_pidns()  argument
237 	if (ns->level <= pid->level)  in pid_in_current_pidns()
238 		return pid->numbers[ns->level].ns == ns;  in pid_in_current_pidns()
247 	struct pid *pid = pidfd_pid(file);  in pidfd_info()  local
265 	 * Restrict information retrieval to tasks within the caller's pid  in pidfd_info()
268 	if (!pid_in_current_pidns(pid))  in pidfd_info()
283 	task = get_pid_task(pid, PIDTYPE_PID);  in pidfd_info()
326 	 * Copy pid/tgid last, to reduce the chances the information might be  in pidfd_info()
336 	kinfo.pid = task_pid_vnr(task);  in pidfd_info()
339 	if (kinfo.pid == 0 || kinfo.tgid == 0 || (kinfo.ppid == 0 && kinfo.pid != 1))  in pidfd_info()
512 struct pid *pidfd_pid(const struct file *file)  in pidfd_pid()
521  * reference to struct pid being held that won't be released until the
525  * If this struct pid is referred to by a pidfd then
527  * pid. Since we've taken a reference on it there's now an additional
529  * it again in a second and we know that the pid is kept alive anyway.
611 	struct pid *pid = inode->i_private;  in pidfs_evict_inode()  local
614 	put_pid(pid);  in pidfs_evict_inode()
661 	const struct pid *pid = inode->i_private;  in pidfs_encode_fh()  local
669 	*(u64 *)fh = pid->ino;  in pidfs_encode_fh()
676 	const struct pid *pid = rb_entry(node, struct pid, pidfs_node);  in pidfs_ino_find()  local
678 	if (pid_ino < pid->ino)  in pidfs_ino_find()
680 	if (pid_ino > pid->ino)  in pidfs_ino_find()
685 /* Find a struct pid based on the inode number. */
686 static struct pid *pidfs_ino_get_pid(u64 ino)  in pidfs_ino_get_pid()
688 	struct pid *pid;  in pidfs_ino_get_pid()  local
703 	pid = rb_entry(node, struct pid, pidfs_node);  in pidfs_ino_get_pid()
705 	/* Within our pid namespace hierarchy? */  in pidfs_ino_get_pid()
706 	if (pid_vnr(pid) == 0)  in pidfs_ino_get_pid()
709 	return get_pid(pid);  in pidfs_ino_get_pid()
719 	struct pid *pid;  in pidfs_fh_to_dentry()  local
732 	pid = pidfs_ino_get_pid(pid_ino);  in pidfs_fh_to_dentry()
733 	if (!pid)  in pidfs_fh_to_dentry()
736 	ret = path_from_stashed(&pid->stashed, pidfs_mnt, pid, &path);  in pidfs_fh_to_dentry()
759 	 * pidfd_ino_get_pid() will verify that the struct pid is part  in pidfs_export_permission()
760 	 * of the caller's pid namespace hierarchy. No further  in pidfs_export_permission()
766 static inline bool pidfs_pid_valid(struct pid *pid, const struct path *path,  in pidfs_pid_valid()  argument
777 	 * pidfd has been allocated perform another check that the pid  in pidfs_pid_valid()
781 	 * linkage has been established for @pid yet and the kernel is  in pidfs_pid_valid()
791 	 * Since pidfs_exit() is called before struct pid's task linkage  in pidfs_pid_valid()
793 	 * was already attached to struct pid and exit information was  in pidfs_pid_valid()
796 	if (unlikely(!pid_has_task(pid, type))) {  in pidfs_pid_valid()
826 	const struct pid *pid = data;  in pidfs_init_inode()  local
833 	inode->i_ino = pidfs_ino(pid->ino);  in pidfs_init_inode()
834 	inode->i_generation = pidfs_gen(pid->ino);  in pidfs_init_inode()
840 	struct pid *pid = data;  in pidfs_put_data()  local
841 	put_pid(pid);  in pidfs_put_data()
870 struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags)  in pidfs_alloc_file()  argument
883 	ret = path_from_stashed(&pid->stashed, pidfs_mnt, get_pid(pid), &path);  in pidfs_alloc_file()
887 	if (!pidfs_pid_valid(pid, &path, flags))  in pidfs_alloc_file()