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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check_gcr_el1_cswitch.c (2657B)

      1// SPDX-License-Identifier: GPL-2.0
      2// Copyright (C) 2020 ARM Limited
      3
      4#define _GNU_SOURCE
      5
      6#include <errno.h>
      7#include <pthread.h>
      8#include <stdint.h>
      9#include <stdio.h>
     10#include <stdlib.h>
     11#include <time.h>
     12#include <unistd.h>
     13#include <sys/auxv.h>
     14#include <sys/mman.h>
     15#include <sys/prctl.h>
     16#include <sys/types.h>
     17#include <sys/wait.h>
     18
     19#include "kselftest.h"
     20#include "mte_common_util.h"
     21
     22#include "mte_def.h"
     23
     24#define NUM_ITERATIONS		1024
     25#define MAX_THREADS		5
     26#define THREAD_ITERATIONS	1000
     27
     28void *execute_thread(void *x)
     29{
     30	pid_t pid = *((pid_t *)x);
     31	pid_t tid = gettid();
     32	uint64_t prctl_tag_mask;
     33	uint64_t prctl_set;
     34	uint64_t prctl_get;
     35	uint64_t prctl_tcf;
     36
     37	srand(time(NULL) ^ (pid << 16) ^ (tid << 16));
     38
     39	prctl_tag_mask = rand() & 0xffff;
     40
     41	if (prctl_tag_mask % 2)
     42		prctl_tcf = PR_MTE_TCF_SYNC;
     43	else
     44		prctl_tcf = PR_MTE_TCF_ASYNC;
     45
     46	prctl_set = PR_TAGGED_ADDR_ENABLE | prctl_tcf | (prctl_tag_mask << PR_MTE_TAG_SHIFT);
     47
     48	for (int j = 0; j < THREAD_ITERATIONS; j++) {
     49		if (prctl(PR_SET_TAGGED_ADDR_CTRL, prctl_set, 0, 0, 0)) {
     50			perror("prctl() failed");
     51			goto fail;
     52		}
     53
     54		prctl_get = prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0);
     55
     56		if (prctl_set != prctl_get) {
     57			ksft_print_msg("Error: prctl_set: 0x%lx != prctl_get: 0x%lx\n",
     58						prctl_set, prctl_get);
     59			goto fail;
     60		}
     61	}
     62
     63	return (void *)KSFT_PASS;
     64
     65fail:
     66	return (void *)KSFT_FAIL;
     67}
     68
     69int execute_test(pid_t pid)
     70{
     71	pthread_t thread_id[MAX_THREADS];
     72	int thread_data[MAX_THREADS];
     73
     74	for (int i = 0; i < MAX_THREADS; i++)
     75		pthread_create(&thread_id[i], NULL,
     76			       execute_thread, (void *)&pid);
     77
     78	for (int i = 0; i < MAX_THREADS; i++)
     79		pthread_join(thread_id[i], (void *)&thread_data[i]);
     80
     81	for (int i = 0; i < MAX_THREADS; i++)
     82		if (thread_data[i] == KSFT_FAIL)
     83			return KSFT_FAIL;
     84
     85	return KSFT_PASS;
     86}
     87
     88int mte_gcr_fork_test(void)
     89{
     90	pid_t pid;
     91	int results[NUM_ITERATIONS];
     92	pid_t cpid;
     93	int res;
     94
     95	for (int i = 0; i < NUM_ITERATIONS; i++) {
     96		pid = fork();
     97
     98		if (pid < 0)
     99			return KSFT_FAIL;
    100
    101		if (pid == 0) {
    102			cpid = getpid();
    103
    104			res = execute_test(cpid);
    105
    106			exit(res);
    107		}
    108	}
    109
    110	for (int i = 0; i < NUM_ITERATIONS; i++) {
    111		wait(&res);
    112
    113		if (WIFEXITED(res))
    114			results[i] = WEXITSTATUS(res);
    115		else
    116			--i;
    117	}
    118
    119	for (int i = 0; i < NUM_ITERATIONS; i++)
    120		if (results[i] == KSFT_FAIL)
    121			return KSFT_FAIL;
    122
    123	return KSFT_PASS;
    124}
    125
    126int main(int argc, char *argv[])
    127{
    128	int err;
    129
    130	err = mte_default_setup();
    131	if (err)
    132		return err;
    133
    134	ksft_set_plan(1);
    135
    136	evaluate_test(mte_gcr_fork_test(),
    137		"Verify that GCR_EL1 is set correctly on context switch\n");
    138
    139	mte_restore_setup();
    140	ksft_print_cnts();
    141
    142	return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
    143}