summaryrefslogtreecommitdiffstats
path: root/kernel/module/tracking.c
blob: 26d812e0761526021087937754e38c4e9011b0d7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
// 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);

int try_add_tainted_module(struct module *mod)
{
	struct mod_unload_taint *mod_taint;

	module_assert_mutex_or_preempt();

	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(sizeof(*mod_taint), GFP_KERNEL);
	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_FS
static 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)
{
	struct dentry *dir;

	dir = debugfs_create_dir("modules", NULL);
	debugfs_create_file("unloaded_tainted", 0444, dir, NULL,
			    &unloaded_tainted_modules_fops);

	return 0;
}
module_init(unloaded_tainted_modules_init);
#endif /* CONFIG_DEBUG_FS */