1// Test that chained origins are fork-safe.
2// Run a number of threads that create new chained origins, then fork
3// and verify that origin reads do not deadlock in the child process.
4//
5// RUN: %clangxx_dfsan -mllvm -dfsan-fast-16-labels=true %s -o %t
6// RUN: %run %t 2>&1 | FileCheck %s
7//
8// RUN: %clangxx_dfsan -mllvm -dfsan-track-origins=1 -mllvm -dfsan-fast-16-labels=true %s -o %t
9// RUN: DFSAN_OPTIONS=store_context_size=1000,origin_history_size=0,origin_history_per_stack_limit=0 %run %t 2>&1 | FileCheck %s
10//
11// REQUIRES: x86_64-target-arch
12
13#include <assert.h>
14#include <errno.h>
15#include <pthread.h>
16#include <signal.h>
17#include <stdio.h>
18#include <stdlib.h>
19#include <sys/time.h>
20#include <sys/types.h>
21#include <sys/wait.h>
22#include <unistd.h>
23
24#include <sanitizer/dfsan_interface.h>
25
26int done;
27
28void copy_labels_thread2() {
29 volatile int x = 0;
30 volatile int v = 0;
31 dfsan_set_label(8, (void *)&x, sizeof(x));
32 while (true) {
33 v = x;
34 x = v;
35 if (__atomic_load_n(&done, __ATOMIC_RELAXED))
36 return;
37 }
38}
39
40void copy_labels_thread1(int level) {
41 if (!level)
42 copy_labels_thread2();
43 else
44 copy_labels_thread1(level - 1);
45}
46
47void *copy_labels_thread(void *id) {
48 copy_labels_thread1((long)id);
49 return 0;
50}
51
52// Run through stackdepot in the child process.
53// If any of the hash table cells are locked, this may deadlock.
54void child() {
55 volatile int x = 0;
56 volatile int v = 0;
57 dfsan_set_label(16, (void *)&x, sizeof(x));
58 for (int i = 0; i < 10000; ++i) {
59 v = x;
60 x = v;
61 }
62 write(2, "done\n", 5);
63}
64
65void test() {
66 const int kThreads = 10;
67 pthread_t t[kThreads];
68 for (int i = 0; i < kThreads; ++i)
69 pthread_create(&t[i], NULL, copy_labels_thread, (void *)(long)i);
70 usleep(100000);
71 pid_t pid = fork();
72 if (pid) {
73 // parent
74 __atomic_store_n(&done, 1, __ATOMIC_RELAXED);
75 pid_t p;
76 while ((p = wait(NULL)) == -1) {
77 }
78 } else {
79 // child
80 child();
81 }
82}
83
84int main() {
85 const int kChildren = 20;
86 for (int i = 0; i < kChildren; ++i) {
87 pid_t pid = fork();
88 assert(dfsan_get_label(pid) == 0);
89 if (pid) {
90 // parent
91 } else {
92 test();
93 exit(0);
94 }
95 }
96
97 for (int i = 0; i < kChildren; ++i) {
98 pid_t p;
99 while ((p = wait(NULL)) == -1) {
100 }
101 }
102
103 return 0;
104}
105
106// Expect 20 (== kChildren) "done" messages.
107// CHECK-COUNT-20: done
108