security/integrity/iint.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2008 IBM Corporation
 *
 * Authors:
 * Mimi Zohar <zohar@us.ibm.com>
 *
 * File: integrity_iint.c
 *	- initialize the integrity directory in securityfs
 *	- load IMA and EVM keys
 */
#include <linux/security.h>
#include "integrity.h"

struct dentry *integrity_dir;

/*
 * integrity_kernel_read - read data from the file
 *
 * This is a function for reading file content instead of kernel_read().
 * It does not perform locking checks to ensure it cannot be blocked.
 * It does not perform security checks because it is irrelevant for IMA.
 *
 */
int integrity_kernel_read(struct file *file, loff_t offset,
			  void *addr, unsigned long count)
{
	return __kernel_read(file, addr, count, &offset);
}

/*
 * integrity_load_keys - load integrity keys hook
 *
 * Hooks is called from init/main.c:kernel_init_freeable()
 * when rootfs is ready
 */
void __init integrity_load_keys(void)
{
	ima_load_x509();

	if (!IS_ENABLED(CONFIG_IMA_LOAD_X509))
		evm_load_x509();
}

int __init integrity_fs_init(void)
{
	if (integrity_dir)
		return 0;

	integrity_dir = securityfs_create_dir("integrity", NULL);
	if (IS_ERR(integrity_dir)) {
		int ret = PTR_ERR(integrity_dir);

		if (ret != -ENODEV)
			pr_err("Unable to create integrity sysfs dir: %d\n",
			       ret);
		integrity_dir = NULL;
		return ret;
	}

	return 0;
}

void __init integrity_fs_fini(void)
{
	if (!integrity_dir || !simple_empty(integrity_dir))
		return;

	securityfs_remove(integrity_dir);
	integrity_dir = NULL;
}