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 %s -o %t
6// RUN: %run %t 2>&1 | FileCheck %s
7//
8// RUN: %clangxx_dfsan -mllvm -dfsan-track-origins=1 %s -o %t
9// RUN: env DFSAN_OPTIONS=store_context_size=1000,origin_history_size=0,origin_history_per_stack_limit=0 %run %t 2>&1 | FileCheck %s
10
11#include <assert.h>
12#include <errno.h>
13#include <pthread.h>
14#include <signal.h>
15#include <stdio.h>
16#include <stdlib.h>
17#include <sys/time.h>
18#include <sys/types.h>
19#include <sys/wait.h>
20#include <unistd.h>
21
22#include <sanitizer/dfsan_interface.h>
23
24int done;
25
26void copy_labels_thread2() {
27 volatile int x = 0;
28 volatile int v = 0;
29 dfsan_set_label(label: 8, addr: (void *)&x, size: sizeof(x));
30 while (true) {
31 v = x;
32 x = v;
33 if (__atomic_load_n(&done, __ATOMIC_RELAXED))
34 return;
35 }
36}
37
38void copy_labels_thread1(int level) {
39 if (!level)
40 copy_labels_thread2();
41 else
42 copy_labels_thread1(level: level - 1);
43}
44
45void *copy_labels_thread(void *id) {
46 copy_labels_thread1(level: (long)id);
47 return 0;
48}
49
50// Run through stackdepot in the child process.
51// If any of the hash table cells are locked, this may deadlock.
52void child() {
53 volatile int x = 0;
54 volatile int v = 0;
55 dfsan_set_label(label: 16, addr: (void *)&x, size: sizeof(x));
56 for (int i = 0; i < 10000; ++i) {
57 v = x;
58 x = v;
59 }
60 write(fd: 2, buf: "done\n", n: 5);
61}
62
63void test() {
64 const int kThreads = 10;
65 pthread_t t[kThreads];
66 for (int i = 0; i < kThreads; ++i)
67 pthread_create(newthread: &t[i], NULL, start_routine: copy_labels_thread, arg: (void *)(long)i);
68 usleep(useconds: 100000);
69 pid_t pid = fork();
70 if (pid) {
71 // parent
72 __atomic_store_n(&done, 1, __ATOMIC_RELAXED);
73 pid_t p;
74 while ((p = wait(NULL)) == -1) {
75 }
76 } else {
77 // child
78 child();
79 }
80}
81
82int main() {
83 const int kChildren = 20;
84 for (int i = 0; i < kChildren; ++i) {
85 pid_t pid = fork();
86 assert(dfsan_get_label(pid) == 0);
87 if (pid) {
88 // parent
89 } else {
90 test();
91 exit(status: 0);
92 }
93 }
94
95 for (int i = 0; i < kChildren; ++i) {
96 pid_t p;
97 while ((p = wait(NULL)) == -1) {
98 }
99 }
100
101 return 0;
102}
103
104// Expect 20 (== kChildren) "done" messages.
105// CHECK-COUNT-20: done
106

source code of compiler-rt/test/dfsan/fork.cpp