xref: /linux/tools/testing/selftests/arm64/mte/check_gcr_el1_cswitch.c (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
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 
execute_thread(void * x)28 void *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 
65 fail:
66 	return (void *)KSFT_FAIL;
67 }
68 
execute_test(pid_t pid)69 int 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 
mte_gcr_fork_test(void)88 int 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 
main(int argc,char * argv[])126 int 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 }
144