check_gcr_el1_cswitch.c

  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}