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// RUN: %clang_tsan -O1 %s -o %t && %env_tsan_opts=report_atomic_races=0 %run %t 2>&1 | FileCheck %s
// This test exposed non-atomicity in mmap interceptor
// which made shadow for the region temporarily unmapped.
// This resulted in crashes in the Accesser thread.
#include "test.h"
#include <errno.h>
#include <sys/mman.h>
// The size needs to be large enough to trigger
// large region optimization in the runtime.
const size_t kMmapSize = 16 << 20;
void *Remapper(void *arg) {
for (;;) {
void *p = mmap(arg, kMmapSize, PROT_READ | PROT_WRITE,
MAP_FIXED | MAP_PRIVATE | MAP_ANON, -1, 0);
if (p == MAP_FAILED)
exit(printf("mmap failed: %d\n", errno));
}
return 0;
}
void *Accesser(void *arg) {
unsigned rnd = time(0);
for (;;) {
int index = rand_r(&rnd) % kMmapSize;
char *p = &((char *)arg)[index];
__atomic_fetch_add(p, 1, __ATOMIC_ACQ_REL);
}
return 0;
}
int main() {
void *p = mmap(0, kMmapSize, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON, -1, 0);
if (p == MAP_FAILED)
exit(printf("mmap failed: %d\n", errno));
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
pthread_t th[2];
if (pthread_create(&th[0], &attr, Remapper, p))
exit(printf("pthread_create failed: %d\n", errno));
if (pthread_create(&th[1], &attr, Accesser, p))
exit(printf("pthread_create failed: %d\n", errno));
pthread_attr_destroy(&attr);
sleep(3);
fprintf(stderr, "DONE\n");
}
// CHECK: DONE
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