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// Test that chained origins are fork-safe.
// Run a number of threads that create new chained origins, then fork
// and verify that origin reads do not deadlock in the child process.
// RUN: %clangxx_msan -std=c++11 -fsanitize-memory-track-origins=2 -g -O3 %s -o %t
// RUN: MSAN_OPTIONS=store_context_size=1000,origin_history_size=0,origin_history_per_stack_limit=0 %run %t 2>&1 | FileCheck %s
// Fun fact: if test output is redirected to a file (as opposed to
// being piped directly to FileCheck), we may lose some "done"s due to
// a kernel bug:
// https://lkml.org/lkml/2014/2/17/324
// Flaky on PPC64.
// UNSUPPORTED: powerpc64-target-arch
// UNSUPPORTED: powerpc64le-target-arch
#include <pthread.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <signal.h>
#include <errno.h>
#include <sanitizer/msan_interface.h>
int done;
void copy_uninit_thread2() {
volatile int x;
volatile int v;
while (true) {
v = x;
x = v;
if (__atomic_load_n(&done, __ATOMIC_RELAXED))
return;
}
}
void copy_uninit_thread1(int level) {
if (!level)
copy_uninit_thread2();
else
copy_uninit_thread1(level - 1);
}
void *copy_uninit_thread(void *id) {
copy_uninit_thread1((long)id);
return 0;
}
// Run through stackdepot in the child process.
// If any of the hash table cells are locked, this may deadlock.
void child() {
volatile int x;
volatile int v;
for (int i = 0; i < 10000; ++i) {
v = x;
x = v;
}
write(2, "done\n", 5);
}
void test() {
const int kThreads = 10;
pthread_t t[kThreads];
for (int i = 0; i < kThreads; ++i)
pthread_create(&t[i], NULL, copy_uninit_thread, (void*)(long)i);
usleep(100000);
pid_t pid = fork();
if (pid) {
// parent
__atomic_store_n(&done, 1, __ATOMIC_RELAXED);
pid_t p;
while ((p = wait(NULL)) == -1) { }
} else {
// child
child();
}
}
int main() {
const int kChildren = 20;
for (int i = 0; i < kChildren; ++i) {
pid_t pid = fork();
if (pid) {
// parent
} else {
test();
exit(0);
}
}
for (int i = 0; i < kChildren; ++i) {
pid_t p;
while ((p = wait(NULL)) == -1) { }
}
return 0;
}
// Expect 20 (== kChildren) "done" messages.
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
// CHECK: done
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