// SPDX-License-Identifier: GPL-2.0-or-later/* * Module taint unload tracking support * * Copyright (C) 2022 Aaron Tomlin */ #include <linux/module.h>#include <linux/string.h>#include <linux/printk.h>#include <linux/slab.h>#include <linux/list.h>#include <linux/debugfs.h>#include <linux/rculist.h>#include "internal.h" static LIST_HEAD(unloaded_tainted_modules);extern struct dentry *mod_debugfs_root; int try_add_tainted_module(struct module *mod){	struct mod_unload_taint *mod_taint; 	if (!mod->taints)		goto out; 	list_for_each_entry_rcu(mod_taint, &unloaded_tainted_modules, list,				lockdep_is_held(&module_mutex)) {		if (!strcmp(mod_taint->name, mod->name) &&		    mod_taint->taints & mod->taints) {			mod_taint->count++;			goto out;		}	} 	mod_taint = kmalloc_obj(*mod_taint);	if (unlikely(!mod_taint))		return -ENOMEM;	strscpy(mod_taint->name, mod->name, MODULE_NAME_LEN);	mod_taint->taints = mod->taints;	list_add_rcu(&mod_taint->list, &unloaded_tainted_modules);	mod_taint->count = 1;out:	return 0;} void print_unloaded_tainted_modules(void){	struct mod_unload_taint *mod_taint;	char buf[MODULE_FLAGS_BUF_SIZE]; 	if (!list_empty(&unloaded_tainted_modules)) {		printk(KERN_DEFAULT "Unloaded tainted modules:");		list_for_each_entry_rcu(mod_taint, &unloaded_tainted_modules,					list) {			size_t l; 			l = module_flags_taint(mod_taint->taints, buf);			buf[l++] = '\0';			pr_cont(" %s(%s):%llu", mod_taint->name, buf,				mod_taint->count);		}	}} #ifdef CONFIG_DEBUG_FSstatic void *unloaded_tainted_modules_seq_start(struct seq_file *m, loff_t *pos)	__acquires(rcu){	rcu_read_lock();	return seq_list_start_rcu(&unloaded_tainted_modules, *pos);} static void *unloaded_tainted_modules_seq_next(struct seq_file *m, void *p, loff_t *pos){	return seq_list_next_rcu(p, &unloaded_tainted_modules, pos);} static void unloaded_tainted_modules_seq_stop(struct seq_file *m, void *p)	__releases(rcu){	rcu_read_unlock();} static int unloaded_tainted_modules_seq_show(struct seq_file *m, void *p){	struct mod_unload_taint *mod_taint;	char buf[MODULE_FLAGS_BUF_SIZE];	size_t l; 	mod_taint = list_entry(p, struct mod_unload_taint, list);	l = module_flags_taint(mod_taint->taints, buf);	buf[l++] = '\0'; 	seq_printf(m, "%s (%s) %llu", mod_taint->name, buf, mod_taint->count);	seq_puts(m, "\n"); 	return 0;} static const struct seq_operations unloaded_tainted_modules_seq_ops = {	.start = unloaded_tainted_modules_seq_start,	.next  = unloaded_tainted_modules_seq_next,	.stop  = unloaded_tainted_modules_seq_stop,	.show  = unloaded_tainted_modules_seq_show,}; static int unloaded_tainted_modules_open(struct inode *inode, struct file *file){	return seq_open(file, &unloaded_tainted_modules_seq_ops);} static const struct file_operations unloaded_tainted_modules_fops = {	.open = unloaded_tainted_modules_open,	.read = seq_read,	.llseek = seq_lseek,	.release = seq_release,}; static int __init unloaded_tainted_modules_init(void){	debugfs_create_file("unloaded_tainted", 0444, mod_debugfs_root, NULL,			    &unloaded_tainted_modules_fops);	return 0;}module_init(unloaded_tainted_modules_init);#endif /* CONFIG_DEBUG_FS */