128 lines · cpp
1// Test that chained origins are fork-safe.2// Run a number of threads that create new chained origins, then fork3// and verify that origin reads do not deadlock in the child process.4 5// RUN: %clangxx_msan -std=c++11 -fsanitize-memory-track-origins=2 -g -O3 %s -o %t6// RUN: env MSAN_OPTIONS=store_context_size=1000,origin_history_size=0,origin_history_per_stack_limit=0 %run %t 2>&1 | FileCheck %s7 8// Fun fact: if test output is redirected to a file (as opposed to9// being piped directly to FileCheck), we may lose some "done"s due to10// a kernel bug:11// https://lkml.org/lkml/2014/2/17/32412 13// Flaky on PPC64.14// UNSUPPORTED: powerpc64-target-arch15// UNSUPPORTED: powerpc64le-target-arch16 17// Sometimes hangs18// UNSUPPORTED: target={{.*netbsd.*}}19 20#include <pthread.h>21#include <unistd.h>22#include <stdio.h>23#include <stdlib.h>24#include <sys/types.h>25#include <sys/wait.h>26#include <sys/time.h>27#include <signal.h>28#include <errno.h>29 30#include <sanitizer/msan_interface.h>31 32int done;33 34void copy_uninit_thread2() {35 volatile int x;36 volatile int v;37 while (true) {38 v = x;39 x = v;40 if (__atomic_load_n(&done, __ATOMIC_RELAXED))41 return;42 }43}44 45void copy_uninit_thread1(int level) {46 if (!level)47 copy_uninit_thread2();48 else49 copy_uninit_thread1(level - 1);50}51 52void *copy_uninit_thread(void *id) {53 copy_uninit_thread1((long)id);54 return 0;55}56 57// Run through stackdepot in the child process.58// If any of the hash table cells are locked, this may deadlock.59void child() {60 volatile int x;61 volatile int v;62 for (int i = 0; i < 10000; ++i) {63 v = x;64 x = v;65 }66 write(2, "done\n", 5);67}68 69void test() {70 const int kThreads = 10;71 pthread_t t[kThreads];72 for (int i = 0; i < kThreads; ++i)73 pthread_create(&t[i], NULL, copy_uninit_thread, (void*)(long)i);74 usleep(100000);75 pid_t pid = fork();76 if (pid) {77 // parent78 __atomic_store_n(&done, 1, __ATOMIC_RELAXED);79 pid_t p;80 while ((p = wait(NULL)) == -1) { }81 } else {82 // child83 child();84 }85}86 87int main() {88 const int kChildren = 20;89 for (int i = 0; i < kChildren; ++i) {90 pid_t pid = fork();91 if (pid) {92 // parent93 } else {94 test();95 exit(0);96 }97 }98 99 for (int i = 0; i < kChildren; ++i) {100 pid_t p;101 while ((p = wait(NULL)) == -1) { }102 }103 104 return 0;105}106 107// Expect 20 (== kChildren) "done" messages.108// CHECK: done109// CHECK: done110// CHECK: done111// CHECK: done112// CHECK: done113// CHECK: done114// CHECK: done115// CHECK: done116// CHECK: done117// CHECK: done118// CHECK: done119// CHECK: done120// CHECK: done121// CHECK: done122// CHECK: done123// CHECK: done124// CHECK: done125// CHECK: done126// CHECK: done127// CHECK: done128