_cgo_tsan_acquire();
	p = mmap(addr, length, prot, flags, fd, offset);
	_cgo_tsan_release();
	if (p == MAP_FAILED) {
		/* This is what the Go code expects on failure.  */
		return (uintptr_t)errno;
	}
	return (uintptr_t)p;
}

void
x_cgo_munmap(void *addr, uintptr_t length) {
	int r;

	_cgo_tsan_acquire();
	r = munmap(addr, length);
	_cgo_tsan_release();
	if (r < 0) {

__attribute__ ((unused))
static void _cgo_tsan_acquire() {
	__tsan_acquire(&_cgo_sync);
}

__attribute__ ((unused))
static void _cgo_tsan_release() {
	__tsan_release(&_cgo_sync);
}

#else // !defined(CGO_TSAN)

#define _cgo_tsan_acquire()
#define _cgo_tsan_release()

	// bounds points into the Go stack. TSAN can't see the synchronization
	// in Go around stack reuse.
	_cgo_tsan_acquire();
	bounds[0] = (uintptr)addr - size;
	bounds[1] = (uintptr)addr;
	_cgo_tsan_release();

	}
}

extern void crosscall_ppc64(void (*fn)(void), void *g);

static void*
threadentry(void *v)
{
	ThreadStart ts;

	ts = *(ThreadStart*)v;
	_cgo_tsan_acquire();
	free(v);
	_cgo_tsan_release();

	// Save g for this thread in C TLS
	setg_gcc((void*)ts.g);

	crosscall_ppc64(ts.fn, (void*)ts.g);
	return nil;

	}
}

extern void crosscall1(void (*fn)(void), void (*setg_gcc)(void*), void *g);
static void*
threadentry(void *v)
{
	ThreadStart ts;

	ts = *(ThreadStart*)v;
	_cgo_tsan_acquire();
	free(v);
	_cgo_tsan_release();

	crosscall1(ts.fn, setg_gcc, (void*)ts.g);
	return nil;

	// bounds points into the Go stack. TSAN can't see the synchronization
	// in Go around stack reuse.
	_cgo_tsan_acquire();
	bounds[0] = (uintptr)addr;
	bounds[1] = (uintptr)addr + size;
	_cgo_tsan_release();

	}
}

extern void crosscall1(void (*fn)(void), void (*setg_gcc)(void*), void *g);
static void*
threadentry(void *v)
{
	ThreadStart ts;

	ts = *(ThreadStart*)v;
	_cgo_tsan_acquire();
	free(v);
	_cgo_tsan_release();

	crosscall1(ts.fn, setg_gcc, (void*)ts.g);
	return nil;