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 <fcntl.h>
8 #include <signal.h>
9 #include <stdlib.h>
10 #include <stdio.h>
11 #include <string.h>
12 #include <ucontext.h>
13 #include <unistd.h>
14 #include <sys/mman.h>
15
16 #include "kselftest.h"
17 #include "mte_common_util.h"
18 #include "mte_def.h"
19
20 static size_t page_sz;
21
check_usermem_access_fault(int mem_type,int mode,int mapping)22 static int check_usermem_access_fault(int mem_type, int mode, int mapping)
23 {
24 int fd, i, err;
25 char val = 'A';
26 size_t len, read_len;
27 void *ptr, *ptr_next;
28
29 err = KSFT_FAIL;
30 len = 2 * page_sz;
31 mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
32 fd = create_temp_file();
33 if (fd == -1)
34 return KSFT_FAIL;
35 for (i = 0; i < len; i++)
36 write(fd, &val, sizeof(val));
37 lseek(fd, 0, 0);
38 ptr = mte_allocate_memory(len, mem_type, mapping, true);
39 if (check_allocated_memory(ptr, len, mem_type, true) != KSFT_PASS) {
40 close(fd);
41 return KSFT_FAIL;
42 }
43 mte_initialize_current_context(mode, (uintptr_t)ptr, len);
44 /* Copy from file into buffer with valid tag */
45 read_len = read(fd, ptr, len);
46 mte_wait_after_trig();
47 if (cur_mte_cxt.fault_valid || read_len < len)
48 goto usermem_acc_err;
49 /* Verify same pattern is read */
50 for (i = 0; i < len; i++)
51 if (*(char *)(ptr + i) != val)
52 break;
53 if (i < len)
54 goto usermem_acc_err;
55
56 /* Tag the next half of memory with different value */
57 ptr_next = (void *)((unsigned long)ptr + page_sz);
58 ptr_next = mte_insert_new_tag(ptr_next);
59 mte_set_tag_address_range(ptr_next, page_sz);
60
61 lseek(fd, 0, 0);
62 /* Copy from file into buffer with invalid tag */
63 read_len = read(fd, ptr, len);
64 mte_wait_after_trig();
65 /*
66 * Accessing user memory in kernel with invalid tag should fail in sync
67 * mode without fault but may not fail in async mode as per the
68 * implemented MTE userspace support in Arm64 kernel.
69 */
70 if (mode == MTE_SYNC_ERR &&
71 !cur_mte_cxt.fault_valid && read_len < len) {
72 err = KSFT_PASS;
73 } else if (mode == MTE_ASYNC_ERR &&
74 !cur_mte_cxt.fault_valid && read_len == len) {
75 err = KSFT_PASS;
76 }
77 usermem_acc_err:
78 mte_free_memory((void *)ptr, len, mem_type, true);
79 close(fd);
80 return err;
81 }
82
main(int argc,char * argv[])83 int main(int argc, char *argv[])
84 {
85 int err;
86
87 page_sz = getpagesize();
88 if (!page_sz) {
89 ksft_print_msg("ERR: Unable to get page size\n");
90 return KSFT_FAIL;
91 }
92 err = mte_default_setup();
93 if (err)
94 return err;
95
96 /* Register signal handlers */
97 mte_register_signal(SIGSEGV, mte_default_handler);
98
99 /* Set test plan */
100 ksft_set_plan(4);
101
102 evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE),
103 "Check memory access from kernel in sync mode, private mapping and mmap memory\n");
104 evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED),
105 "Check memory access from kernel in sync mode, shared mapping and mmap memory\n");
106
107 evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE),
108 "Check memory access from kernel in async mode, private mapping and mmap memory\n");
109 evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED),
110 "Check memory access from kernel in async mode, shared mapping and mmap memory\n");
111
112 mte_restore_setup();
113 ksft_print_cnts();
114 return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
115 }
116