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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rfi_flush.c (3470B)

      1// SPDX-License-Identifier: GPL-2.0+
      2
      3/*
      4 * Copyright 2018 IBM Corporation.
      5 */
      6
      7#define __SANE_USERSPACE_TYPES__
      8
      9#include <sys/types.h>
     10#include <stdint.h>
     11#include <malloc.h>
     12#include <unistd.h>
     13#include <stdlib.h>
     14#include <string.h>
     15#include <stdio.h>
     16#include "utils.h"
     17#include "flush_utils.h"
     18
     19
     20int rfi_flush_test(void)
     21{
     22	char *p;
     23	int repetitions = 10;
     24	int fd, passes = 0, iter, rc = 0;
     25	struct perf_event_read v;
     26	__u64 l1d_misses_total = 0;
     27	unsigned long iterations = 100000, zero_size = 24 * 1024;
     28	unsigned long l1d_misses_expected;
     29	int rfi_flush_orig, rfi_flush;
     30	int have_entry_flush, entry_flush_orig;
     31
     32	SKIP_IF(geteuid() != 0);
     33
     34	// The PMU event we use only works on Power7 or later
     35	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
     36
     37	if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_orig) < 0) {
     38		perror("Unable to read powerpc/rfi_flush debugfs file");
     39		SKIP_IF(1);
     40	}
     41
     42	if (read_debugfs_file("powerpc/entry_flush", &entry_flush_orig) < 0) {
     43		have_entry_flush = 0;
     44	} else {
     45		have_entry_flush = 1;
     46
     47		if (entry_flush_orig != 0) {
     48			if (write_debugfs_file("powerpc/entry_flush", 0) < 0) {
     49				perror("error writing to powerpc/entry_flush debugfs file");
     50				return 1;
     51			}
     52		}
     53	}
     54
     55	rfi_flush = rfi_flush_orig;
     56
     57	fd = perf_event_open_counter(PERF_TYPE_HW_CACHE, PERF_L1D_READ_MISS_CONFIG, -1);
     58	FAIL_IF(fd < 0);
     59
     60	p = (char *)memalign(zero_size, CACHELINE_SIZE);
     61
     62	FAIL_IF(perf_event_enable(fd));
     63
     64	// disable L1 prefetching
     65	set_dscr(1);
     66
     67	iter = repetitions;
     68
     69	/*
     70	 * We expect to see l1d miss for each cacheline access when rfi_flush
     71	 * is set. Allow a small variation on this.
     72	 */
     73	l1d_misses_expected = iterations * (zero_size / CACHELINE_SIZE - 2);
     74
     75again:
     76	FAIL_IF(perf_event_reset(fd));
     77
     78	syscall_loop(p, iterations, zero_size);
     79
     80	FAIL_IF(read(fd, &v, sizeof(v)) != sizeof(v));
     81
     82	if (rfi_flush && v.l1d_misses >= l1d_misses_expected)
     83		passes++;
     84	else if (!rfi_flush && v.l1d_misses < (l1d_misses_expected / 2))
     85		passes++;
     86
     87	l1d_misses_total += v.l1d_misses;
     88
     89	while (--iter)
     90		goto again;
     91
     92	if (passes < repetitions) {
     93		printf("FAIL (L1D misses with rfi_flush=%d: %llu %c %lu) [%d/%d failures]\n",
     94		       rfi_flush, l1d_misses_total, rfi_flush ? '<' : '>',
     95		       rfi_flush ? repetitions * l1d_misses_expected :
     96		       repetitions * l1d_misses_expected / 2,
     97		       repetitions - passes, repetitions);
     98		rc = 1;
     99	} else
    100		printf("PASS (L1D misses with rfi_flush=%d: %llu %c %lu) [%d/%d pass]\n",
    101		       rfi_flush, l1d_misses_total, rfi_flush ? '>' : '<',
    102		       rfi_flush ? repetitions * l1d_misses_expected :
    103		       repetitions * l1d_misses_expected / 2,
    104		       passes, repetitions);
    105
    106	if (rfi_flush == rfi_flush_orig) {
    107		rfi_flush = !rfi_flush_orig;
    108		if (write_debugfs_file("powerpc/rfi_flush", rfi_flush) < 0) {
    109			perror("error writing to powerpc/rfi_flush debugfs file");
    110			return 1;
    111		}
    112		iter = repetitions;
    113		l1d_misses_total = 0;
    114		passes = 0;
    115		goto again;
    116	}
    117
    118	perf_event_disable(fd);
    119	close(fd);
    120
    121	set_dscr(0);
    122
    123	if (write_debugfs_file("powerpc/rfi_flush", rfi_flush_orig) < 0) {
    124		perror("unable to restore original value of powerpc/rfi_flush debugfs file");
    125		return 1;
    126	}
    127
    128	if (have_entry_flush) {
    129		if (write_debugfs_file("powerpc/entry_flush", entry_flush_orig) < 0) {
    130			perror("unable to restore original value of powerpc/entry_flush "
    131			       "debugfs file");
    132			return 1;
    133		}
    134	}
    135
    136	return rc;
    137}
    138
    139int main(int argc, char *argv[])
    140{
    141	return test_harness(rfi_flush_test, "rfi_flush_test");
    142}