1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
/*
* Copyright (c) 2012 The Native Client Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include <assert.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
void *gs_segment_read_only_test(void *unused_thread_arg) {
uint32_t value;
__asm__ volatile("movl %%gs:0, %0" : "=r"(value));
fprintf(stderr, "** intended_exit_status=untrusted_sigsegv_or_equivalent\n");
/*
* Check that the %gs segment is read-only by attempting to write to
* it. We write the same value that it currently contains so that,
* if the write succeeds, we do not corrupt TLS and we can report
* the failure by exiting without crashing (since crashing could
* make the test succeed accidentally).
*
* Note that we expect this instruction to be disallowed by the
* validator in the future, so this program may need to be run with
* validation disabled.
* See http://code.google.com/p/nativeclient/issues/detail?id=2250
*/
__asm__ volatile("movl %0, %%gs:0\n" : : "r"(value));
/* Should not reach here. */
_exit(1);
}
void *gs_segment_size_test(void *unused_thread_arg) {
/*
* Check that the %gs segment is 16 bytes in size by attempting to
* read 1 byte beyond the end.
*/
uint32_t dummy;
fprintf(stderr, "** intended_exit_status=untrusted_sigsegv_or_equivalent\n");
__asm__ volatile("movl %%gs:(16-3), %0" : "=r"(dummy));
/* Should not reach here. */
_exit(1);
}
void run_in_thread(void *(*func)(void *thread_arg)) {
pthread_t tid;
int rc;
rc = pthread_create(&tid, NULL, func, NULL);
assert(rc == 0);
rc = pthread_join(tid, NULL);
assert(rc == 0);
}
int main(int argc, char **argv) {
if (argc != 2) {
fprintf(stderr, "Expected test type argument\n");
return 1;
}
if (strcmp(argv[1], "gs_segment_read_only_test") == 0) {
gs_segment_read_only_test(NULL);
} else if (strcmp(argv[1], "gs_segment_read_only_test_thread") == 0) {
run_in_thread(gs_segment_read_only_test);
} else if (strcmp(argv[1], "gs_segment_size_test") == 0) {
gs_segment_size_test(NULL);
} else if (strcmp(argv[1], "gs_segment_size_test_thread") == 0) {
run_in_thread(gs_segment_size_test);
} else {
fprintf(stderr, "Unrecognised test type argument: %s\n", argv[1]);
}
/* Should not reach here because the test should crash. */
return 1;
}
|
