unaligned_race.cpp
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// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
#include "test.h"
#include <stdint.h>
#define NOINLINE __attribute__((noinline))
volatile uint64_t objs[8*2*(2 + 4 + 8)][2];
// All this mess is to generate unique stack for each race,
// otherwise tsan will suppress similar stacks.
static NOINLINE void access(volatile void *p, int sz, int rw) {
if (rw) {
switch (sz) {
case 0: __sanitizer_unaligned_store16((void *)p, 0); break;
case 1: __sanitizer_unaligned_store32((void *)p, 0); break;
case 2: __sanitizer_unaligned_store64((void *)p, 0); break;
default: exit(1);
}
} else {
switch (sz) {
case 0: __sanitizer_unaligned_load16((void *)p); break;
case 1: __sanitizer_unaligned_load32((void *)p); break;
case 2: __sanitizer_unaligned_load64((void *)p); break;
default: exit(1);
}
}
}
static int accesssize(int sz) {
switch (sz) {
case 0: return 2;
case 1: return 4;
case 2: return 8;
}
exit(1);
}
template<int off, int off2>
static NOINLINE void access3(bool main, int sz1, bool rw, volatile char *p) {
p += off;
if (main) {
access(p, sz1, true);
} else {
p += off2;
if (rw) {
*p = 42;
} else {
if (*p == 42)
printf("bingo!\n");
}
}
}
template<int off>
static NOINLINE void
access2(bool main, int sz1, int off2, bool rw, volatile char *obj) {
if (off2 == 0)
access3<off, 0>(main, sz1, rw, obj);
else if (off2 == 1)
access3<off, 1>(main, sz1, rw, obj);
else if (off2 == 2)
access3<off, 2>(main, sz1, rw, obj);
else if (off2 == 3)
access3<off, 3>(main, sz1, rw, obj);
else if (off2 == 4)
access3<off, 4>(main, sz1, rw, obj);
else if (off2 == 5)
access3<off, 5>(main, sz1, rw, obj);
else if (off2 == 6)
access3<off, 6>(main, sz1, rw, obj);
else if (off2 == 7)
access3<off, 7>(main, sz1, rw, obj);
}
static NOINLINE void
access1(bool main, int off, int sz1, int off2, bool rw, char *obj) {
if (off == 0)
access2<0>(main, sz1, off2, rw, obj);
else if (off == 1)
access2<1>(main, sz1, off2, rw, obj);
else if (off == 2)
access2<2>(main, sz1, off2, rw, obj);
else if (off == 3)
access2<3>(main, sz1, off2, rw, obj);
else if (off == 4)
access2<4>(main, sz1, off2, rw, obj);
else if (off == 5)
access2<5>(main, sz1, off2, rw, obj);
else if (off == 6)
access2<6>(main, sz1, off2, rw, obj);
else if (off == 7)
access2<7>(main, sz1, off2, rw, obj);
}
NOINLINE void Test(bool main) {
volatile uint64_t *obj = objs[0];
for (int off = 0; off < 8; off++) {
for (int sz1 = 0; sz1 < 3; sz1++) {
for (int off2 = 0; off2 < accesssize(sz1); off2++) {
for (int rw = 0; rw < 2; rw++) {
// printf("thr=%d off=%d sz1=%d off2=%d rw=%d p=%p\n",
// main, off, sz1, off2, rw, obj);
access1(main, off, sz1, off2, rw, (char*)obj);
obj += 2;
}
}
}
}
}
void *Thread(void *p) {
(void)p;
barrier_wait(&barrier);
Test(false);
return 0;
}
int main() {
barrier_init(&barrier, 2);
pthread_t th;
pthread_create(&th, 0, Thread, 0);
Test(true);
barrier_wait(&barrier);
pthread_join(th, 0);
}
// CHECK: WARNING: ThreadSanitizer: data race
// CHECK: ThreadSanitizer: reported 224 warnings