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 #define PR_SET_TAGGED_ADDR_CTRL 55
23 #define PR_GET_TAGGED_ADDR_CTRL 56
24 # define PR_TAGGED_ADDR_ENABLE  (1UL << 0)
25 # define PR_MTE_TCF_SHIFT	1
26 # define PR_MTE_TCF_NONE	(0UL << PR_MTE_TCF_SHIFT)
27 # define PR_MTE_TCF_SYNC	(1UL << PR_MTE_TCF_SHIFT)
28 # define PR_MTE_TCF_ASYNC	(2UL << PR_MTE_TCF_SHIFT)
29 # define PR_MTE_TCF_MASK	(3UL << PR_MTE_TCF_SHIFT)
30 # define PR_MTE_TAG_SHIFT	3
31 # define PR_MTE_TAG_MASK	(0xffffUL << PR_MTE_TAG_SHIFT)
32 
33 #include "mte_def.h"
34 
35 #define NUM_ITERATIONS		1024
36 #define MAX_THREADS		5
37 #define THREAD_ITERATIONS	1000
38 
39 void *execute_thread(void *x)
40 {
41 	pid_t pid = *((pid_t *)x);
42 	pid_t tid = gettid();
43 	uint64_t prctl_tag_mask;
44 	uint64_t prctl_set;
45 	uint64_t prctl_get;
46 	uint64_t prctl_tcf;
47 
48 	srand(time(NULL) ^ (pid << 16) ^ (tid << 16));
49 
50 	prctl_tag_mask = rand() & 0xffff;
51 
52 	if (prctl_tag_mask % 2)
53 		prctl_tcf = PR_MTE_TCF_SYNC;
54 	else
55 		prctl_tcf = PR_MTE_TCF_ASYNC;
56 
57 	prctl_set = PR_TAGGED_ADDR_ENABLE | prctl_tcf | (prctl_tag_mask << PR_MTE_TAG_SHIFT);
58 
59 	for (int j = 0; j < THREAD_ITERATIONS; j++) {
60 		if (prctl(PR_SET_TAGGED_ADDR_CTRL, prctl_set, 0, 0, 0)) {
61 			perror("prctl() failed");
62 			goto fail;
63 		}
64 
65 		prctl_get = prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0);
66 
67 		if (prctl_set != prctl_get) {
68 			ksft_print_msg("Error: prctl_set: 0x%lx != prctl_get: 0x%lx\n",
69 						prctl_set, prctl_get);
70 			goto fail;
71 		}
72 	}
73 
74 	return (void *)KSFT_PASS;
75 
76 fail:
77 	return (void *)KSFT_FAIL;
78 }
79 
80 int execute_test(pid_t pid)
81 {
82 	pthread_t thread_id[MAX_THREADS];
83 	int thread_data[MAX_THREADS];
84 
85 	for (int i = 0; i < MAX_THREADS; i++)
86 		pthread_create(&thread_id[i], NULL,
87 			       execute_thread, (void *)&pid);
88 
89 	for (int i = 0; i < MAX_THREADS; i++)
90 		pthread_join(thread_id[i], (void *)&thread_data[i]);
91 
92 	for (int i = 0; i < MAX_THREADS; i++)
93 		if (thread_data[i] == KSFT_FAIL)
94 			return KSFT_FAIL;
95 
96 	return KSFT_PASS;
97 }
98 
99 int mte_gcr_fork_test(void)
100 {
101 	pid_t pid;
102 	int results[NUM_ITERATIONS];
103 	pid_t cpid;
104 	int res;
105 
106 	for (int i = 0; i < NUM_ITERATIONS; i++) {
107 		pid = fork();
108 
109 		if (pid < 0)
110 			return KSFT_FAIL;
111 
112 		if (pid == 0) {
113 			cpid = getpid();
114 
115 			res = execute_test(cpid);
116 
117 			exit(res);
118 		}
119 	}
120 
121 	for (int i = 0; i < NUM_ITERATIONS; i++) {
122 		wait(&res);
123 
124 		if (WIFEXITED(res))
125 			results[i] = WEXITSTATUS(res);
126 		else
127 			--i;
128 	}
129 
130 	for (int i = 0; i < NUM_ITERATIONS; i++)
131 		if (results[i] == KSFT_FAIL)
132 			return KSFT_FAIL;
133 
134 	return KSFT_PASS;
135 }
136 
137 int main(int argc, char *argv[])
138 {
139 	int err;
140 
141 	err = mte_default_setup();
142 	if (err)
143 		return err;
144 
145 	ksft_set_plan(1);
146 
147 	evaluate_test(mte_gcr_fork_test(),
148 		"Verify that GCR_EL1 is set correctly on context switch\n");
149 
150 	mte_restore_setup();
151 	ksft_print_cnts();
152 
153 	return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
154 }
155