tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
kselftest/arm64: Check forked child mte memory accessibility
This test covers the mte memory behaviour of the forked process with
different mapping properties and flags. It checks that all bytes of
forked child memory are accessible with the same tag as that of the
parent and memory accessed outside the tag range causes fault to
occur.
Co-developed-by: Gabor Kertesz <gabor.kertesz@arm.com>
Signed-off-by: Gabor Kertesz <gabor.kertesz@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201002115630.24683-4-amit.kachhap@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
authored by
Amit Daniel Kachhap
and committed by
Will Deacon
dfe537cf
f3b2a26c
+196
+1
tools/testing/selftests/arm64/mte/.gitignore
+1
tools/testing/selftests/arm64/mte/.gitignore
+195
tools/testing/selftests/arm64/mte/check_child_memory.c
+195
tools/testing/selftests/arm64/mte/check_child_memory.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 <signal.h>
8
+
#include <stdio.h>
9
+
#include <stdlib.h>
10
+
#include <string.h>
11
+
#include <ucontext.h>
12
+
#include <sys/wait.h>
13
+
14
+
#include "kselftest.h"
15
+
#include "mte_common_util.h"
16
+
#include "mte_def.h"
17
+
18
+
#define BUFFER_SIZE (5 * MT_GRANULE_SIZE)
19
+
#define RUNS (MT_TAG_COUNT)
20
+
#define UNDERFLOW MT_GRANULE_SIZE
21
+
#define OVERFLOW MT_GRANULE_SIZE
22
+
23
+
static size_t page_size;
24
+
static int sizes[] = {
25
+
1, 537, 989, 1269, MT_GRANULE_SIZE - 1, MT_GRANULE_SIZE,
26
+
/* page size - 1*/ 0, /* page_size */ 0, /* page size + 1 */ 0
27
+
};
28
+
29
+
static int check_child_tag_inheritance(char *ptr, int size, int mode)
30
+
{
31
+
int i, parent_tag, child_tag, fault, child_status;
32
+
pid_t child;
33
+
34
+
parent_tag = MT_FETCH_TAG((uintptr_t)ptr);
35
+
fault = 0;
36
+
37
+
child = fork();
38
+
if (child == -1) {
39
+
ksft_print_msg("FAIL: child process creation\n");
40
+
return KSFT_FAIL;
41
+
} else if (child == 0) {
42
+
mte_initialize_current_context(mode, (uintptr_t)ptr, size);
43
+
/* Do copy on write */
44
+
memset(ptr, '1', size);
45
+
mte_wait_after_trig();
46
+
if (cur_mte_cxt.fault_valid == true) {
47
+
fault = 1;
48
+
goto check_child_tag_inheritance_err;
49
+
}
50
+
for (i = 0 ; i < size ; i += MT_GRANULE_SIZE) {
51
+
child_tag = MT_FETCH_TAG((uintptr_t)(mte_get_tag_address(ptr + i)));
52
+
if (parent_tag != child_tag) {
53
+
ksft_print_msg("FAIL: child mte tag mismatch\n");
54
+
fault = 1;
55
+
goto check_child_tag_inheritance_err;
56
+
}
57
+
}
58
+
mte_initialize_current_context(mode, (uintptr_t)ptr, -UNDERFLOW);
59
+
memset(ptr - UNDERFLOW, '2', UNDERFLOW);
60
+
mte_wait_after_trig();
61
+
if (cur_mte_cxt.fault_valid == false) {
62
+
fault = 1;
63
+
goto check_child_tag_inheritance_err;
64
+
}
65
+
mte_initialize_current_context(mode, (uintptr_t)ptr, size + OVERFLOW);
66
+
memset(ptr + size, '3', OVERFLOW);
67
+
mte_wait_after_trig();
68
+
if (cur_mte_cxt.fault_valid == false) {
69
+
fault = 1;
70
+
goto check_child_tag_inheritance_err;
71
+
}
72
+
check_child_tag_inheritance_err:
73
+
_exit(fault);
74
+
}
75
+
/* Wait for child process to terminate */
76
+
wait(&child_status);
77
+
if (WIFEXITED(child_status))
78
+
fault = WEXITSTATUS(child_status);
79
+
else
80
+
fault = 1;
81
+
return (fault) ? KSFT_FAIL : KSFT_PASS;
82
+
}
83
+
84
+
static int check_child_memory_mapping(int mem_type, int mode, int mapping)
85
+
{
86
+
char *ptr;
87
+
int run, result;
88
+
int item = sizeof(sizes)/sizeof(int);
89
+
90
+
item = sizeof(sizes)/sizeof(int);
91
+
mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
92
+
for (run = 0; run < item; run++) {
93
+
ptr = (char *)mte_allocate_memory_tag_range(sizes[run], mem_type, mapping,
94
+
UNDERFLOW, OVERFLOW);
95
+
if (check_allocated_memory_range(ptr, sizes[run], mem_type,
96
+
UNDERFLOW, OVERFLOW) != KSFT_PASS)
97
+
return KSFT_FAIL;
98
+
result = check_child_tag_inheritance(ptr, sizes[run], mode);
99
+
mte_free_memory_tag_range((void *)ptr, sizes[run], mem_type, UNDERFLOW, OVERFLOW);
100
+
if (result == KSFT_FAIL)
101
+
return result;
102
+
}
103
+
return KSFT_PASS;
104
+
}
105
+
106
+
static int check_child_file_mapping(int mem_type, int mode, int mapping)
107
+
{
108
+
char *ptr, *map_ptr;
109
+
int run, fd, map_size, result = KSFT_PASS;
110
+
int total = sizeof(sizes)/sizeof(int);
111
+
112
+
mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
113
+
for (run = 0; run < total; run++) {
114
+
fd = create_temp_file();
115
+
if (fd == -1)
116
+
return KSFT_FAIL;
117
+
118
+
map_size = sizes[run] + OVERFLOW + UNDERFLOW;
119
+
map_ptr = (char *)mte_allocate_file_memory(map_size, mem_type, mapping, false, fd);
120
+
if (check_allocated_memory(map_ptr, map_size, mem_type, false) != KSFT_PASS) {
121
+
close(fd);
122
+
return KSFT_FAIL;
123
+
}
124
+
ptr = map_ptr + UNDERFLOW;
125
+
mte_initialize_current_context(mode, (uintptr_t)ptr, sizes[run]);
126
+
/* Only mte enabled memory will allow tag insertion */
127
+
ptr = mte_insert_tags((void *)ptr, sizes[run]);
128
+
if (!ptr || cur_mte_cxt.fault_valid == true) {
129
+
ksft_print_msg("FAIL: Insert tags on file based memory\n");
130
+
munmap((void *)map_ptr, map_size);
131
+
close(fd);
132
+
return KSFT_FAIL;
133
+
}
134
+
result = check_child_tag_inheritance(ptr, sizes[run], mode);
135
+
mte_clear_tags((void *)ptr, sizes[run]);
136
+
munmap((void *)map_ptr, map_size);
137
+
close(fd);
138
+
if (result != KSFT_PASS)
139
+
return KSFT_FAIL;
140
+
}
141
+
return KSFT_PASS;
142
+
}
143
+
144
+
int main(int argc, char *argv[])
145
+
{
146
+
int err;
147
+
int item = sizeof(sizes)/sizeof(int);
148
+
149
+
page_size = getpagesize();
150
+
if (!page_size) {
151
+
ksft_print_msg("ERR: Unable to get page size\n");
152
+
return KSFT_FAIL;
153
+
}
154
+
sizes[item - 3] = page_size - 1;
155
+
sizes[item - 2] = page_size;
156
+
sizes[item - 1] = page_size + 1;
157
+
158
+
err = mte_default_setup();
159
+
if (err)
160
+
return err;
161
+
162
+
/* Register SIGSEGV handler */
163
+
mte_register_signal(SIGSEGV, mte_default_handler);
164
+
mte_register_signal(SIGBUS, mte_default_handler);
165
+
166
+
evaluate_test(check_child_memory_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE),
167
+
"Check child anonymous memory with private mapping, precise mode and mmap memory\n");
168
+
evaluate_test(check_child_memory_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED),
169
+
"Check child anonymous memory with shared mapping, precise mode and mmap memory\n");
170
+
evaluate_test(check_child_memory_mapping(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE),
171
+
"Check child anonymous memory with private mapping, imprecise mode and mmap memory\n");
172
+
evaluate_test(check_child_memory_mapping(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED),
173
+
"Check child anonymous memory with shared mapping, imprecise mode and mmap memory\n");
174
+
evaluate_test(check_child_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_PRIVATE),
175
+
"Check child anonymous memory with private mapping, precise mode and mmap/mprotect memory\n");
176
+
evaluate_test(check_child_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_SHARED),
177
+
"Check child anonymous memory with shared mapping, precise mode and mmap/mprotect memory\n");
178
+
179
+
evaluate_test(check_child_file_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE),
180
+
"Check child file memory with private mapping, precise mode and mmap memory\n");
181
+
evaluate_test(check_child_file_mapping(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED),
182
+
"Check child file memory with shared mapping, precise mode and mmap memory\n");
183
+
evaluate_test(check_child_memory_mapping(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE),
184
+
"Check child file memory with private mapping, imprecise mode and mmap memory\n");
185
+
evaluate_test(check_child_memory_mapping(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED),
186
+
"Check child file memory with shared mapping, imprecise mode and mmap memory\n");
187
+
evaluate_test(check_child_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_PRIVATE),
188
+
"Check child file memory with private mapping, precise mode and mmap/mprotect memory\n");
189
+
evaluate_test(check_child_memory_mapping(USE_MPROTECT, MTE_SYNC_ERR, MAP_SHARED),
190
+
"Check child file memory with shared mapping, precise mode and mmap/mprotect memory\n");
191
+
192
+
mte_restore_setup();
193
+
ksft_print_cnts();
194
+
return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
195
+
}