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
|
// RUN: %clangxx_tsan -O0 %s -o %t
// RUN: not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-RACE
// Test size larger than clear_shadow_mmap_threshold, which is handled differently.
// RUN: not %run %t - 262144 2>&1 | FileCheck %s --check-prefix=CHECK-RACE
// RUN: %run %t ignore 2>&1 | FileCheck %s --check-prefix=CHECK-IGNORE
#include <sys/mman.h>
#include <string.h>
#include <assert.h>
#include <atomic>
#include "test.h"
// Use atomic to ensure we do not have a race for the pointer value itself. We
// only want to check races in the mmap'd memory to isolate the test that mmap
// respects ignore annotations.
std::atomic<int*> global_p;
void mmap_ignored(bool ignore, size_t size) {
if (ignore) AnnotateIgnoreWritesBegin(__FILE__, __LINE__);
void *p =
mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
if (ignore) AnnotateIgnoreWritesEnd(__FILE__, __LINE__);
// Use relaxed to retain the race between the mmap call and the memory write
global_p.store((int *)p, std::memory_order_relaxed);
barrier_wait(&barrier);
}
void *WriteToMemory(void *unused) {
barrier_wait(&barrier);
global_p[0] = 7;
return 0;
}
// Create race between allocating (mmap) and writing memory
int main(int argc, const char *argv[]) {
bool ignore = (argc > 1) && (strcmp(argv[1], "ignore") == 0);
size_t size = argc > 2 ? atoi(argv[2]) : sysconf(_SC_PAGESIZE);
barrier_init(&barrier, 2);
pthread_t t;
pthread_create(&t, 0, WriteToMemory, 0);
mmap_ignored(ignore, size);
pthread_join(t, 0);
assert(global_p[0] == 7);
printf("OK\n");
return 0;
}
// CHECK-RACE: WARNING: ThreadSanitizer: data race
// CHECK-RACE: OK
// CHECK-IGNORE-NOT: WARNING: ThreadSanitizer: data race
// CHECK-IGNORE: OK
|
