/* SPDX-License-Identifier: GPL-2.0
 *
 * Copyright (C) 2026 silt <silt@0xC3.win>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, see <https://www.gnu.org/licenses/>.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/printk.h>
#include <linux/types.h>
#include <linux/version.h>
#include <linux/string.h>
#include <asm/msr.h>

MODULE_AUTHOR("silt <silt@0xC3.win>");
MODULE_DESCRIPTION("Implements the mitigation for CVE-2025-54505 as described by AMD-SB-7053");
MODULE_LICENSE("GPL");

static int __init init(void) {
	pr_info("Applying MSR fix for FP-DSS (CVE-2025-54505, AMD-SB-7053)\n");

	int err = msr_set_bit(0xC0011028, 9);
	if (err < 0) {
		pr_warn("Failed to apply fix for FP-DSS: %d\n", err);
	} else if (err == 0) {
		pr_info("Fix was previously applied. Bailing from init.\n");
	}
	pr_info("Fix applied successfully. Bailing from init.\n");
	
	return -1;
}
module_init(init);