cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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imr_selftest.c (3523B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * imr_selftest.c -- Intel Isolated Memory Region self-test driver
      4 *
      5 * Copyright(c) 2013 Intel Corporation.
      6 * Copyright(c) 2015 Bryan O'Donoghue <pure.logic@nexus-software.ie>
      7 *
      8 * IMR self test. The purpose of this module is to run a set of tests on the
      9 * IMR API to validate it's sanity. We check for overlapping, reserved
     10 * addresses and setup/teardown sanity.
     11 *
     12 */
     13
     14#include <asm-generic/sections.h>
     15#include <asm/cpu_device_id.h>
     16#include <asm/imr.h>
     17#include <asm/io.h>
     18
     19#include <linux/init.h>
     20#include <linux/mm.h>
     21#include <linux/types.h>
     22
     23#define SELFTEST KBUILD_MODNAME ": "
     24/**
     25 * imr_self_test_result - Print result string for self test.
     26 *
     27 * @res:	result code - true if test passed false otherwise.
     28 * @fmt:	format string.
     29 * ...		variadic argument list.
     30 */
     31static __printf(2, 3)
     32void __init imr_self_test_result(int res, const char *fmt, ...)
     33{
     34	va_list vlist;
     35
     36	/* Print pass/fail. */
     37	if (res)
     38		pr_info(SELFTEST "pass ");
     39	else
     40		pr_info(SELFTEST "fail ");
     41
     42	/* Print variable string. */
     43	va_start(vlist, fmt);
     44	vprintk(fmt, vlist);
     45	va_end(vlist);
     46
     47	/* Optional warning. */
     48	WARN(res == 0, "test failed");
     49}
     50#undef SELFTEST
     51
     52/**
     53 * imr_self_test
     54 *
     55 * Verify IMR self_test with some simple tests to verify overlap,
     56 * zero sized allocations and 1 KiB sized areas.
     57 *
     58 */
     59static void __init imr_self_test(void)
     60{
     61	phys_addr_t base  = virt_to_phys(&_text);
     62	size_t size = virt_to_phys(&__end_rodata) - base;
     63	const char *fmt_over = "overlapped IMR @ (0x%08lx - 0x%08lx)\n";
     64	int ret;
     65
     66	/* Test zero zero. */
     67	ret = imr_add_range(0, 0, 0, 0);
     68	imr_self_test_result(ret < 0, "zero sized IMR\n");
     69
     70	/* Test exact overlap. */
     71	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
     72	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));
     73
     74	/* Test overlap with base inside of existing. */
     75	base += size - IMR_ALIGN;
     76	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
     77	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));
     78
     79	/* Test overlap with end inside of existing. */
     80	base -= size + IMR_ALIGN * 2;
     81	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
     82	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));
     83
     84	/* Test that a 1 KiB IMR @ zero with read/write all will bomb out. */
     85	ret = imr_add_range(0, IMR_ALIGN, IMR_READ_ACCESS_ALL,
     86			    IMR_WRITE_ACCESS_ALL);
     87	imr_self_test_result(ret < 0, "1KiB IMR @ 0x00000000 - access-all\n");
     88
     89	/* Test that a 1 KiB IMR @ zero with CPU only will work. */
     90	ret = imr_add_range(0, IMR_ALIGN, IMR_CPU, IMR_CPU);
     91	imr_self_test_result(ret >= 0, "1KiB IMR @ 0x00000000 - cpu-access\n");
     92	if (ret >= 0) {
     93		ret = imr_remove_range(0, IMR_ALIGN);
     94		imr_self_test_result(ret == 0, "teardown - cpu-access\n");
     95	}
     96
     97	/* Test 2 KiB works. */
     98	size = IMR_ALIGN * 2;
     99	ret = imr_add_range(0, size, IMR_READ_ACCESS_ALL, IMR_WRITE_ACCESS_ALL);
    100	imr_self_test_result(ret >= 0, "2KiB IMR @ 0x00000000\n");
    101	if (ret >= 0) {
    102		ret = imr_remove_range(0, size);
    103		imr_self_test_result(ret == 0, "teardown 2KiB\n");
    104	}
    105}
    106
    107static const struct x86_cpu_id imr_ids[] __initconst = {
    108	X86_MATCH_VENDOR_FAM_MODEL(INTEL, 5, INTEL_FAM5_QUARK_X1000, NULL),
    109	{}
    110};
    111
    112/**
    113 * imr_self_test_init - entry point for IMR driver.
    114 *
    115 * return: -ENODEV for no IMR support 0 if good to go.
    116 */
    117static int __init imr_self_test_init(void)
    118{
    119	if (x86_match_cpu(imr_ids))
    120		imr_self_test();
    121	return 0;
    122}
    123
    124/**
    125 * imr_self_test_exit - exit point for IMR code.
    126 *
    127 * return:
    128 */
    129device_initcall(imr_self_test_init);