How to get backtrace in libprocessgroup/processgroup.cpp?

Question

In Android, I want get the trace that call processgroup.DoKillProcessGroupOnce(), but I don't know how to use the CallStack.

#include <utils/CallStack.h>

static int DoKillProcessGroupOnce(const char* cgroup, uid_t uid, int initialPid, int signal) {
    android::CallStack::logStack("TRACE1");

But the log says that TRACE1: CallStack::logStackInternal is not linked.

It seems that: reinterpret_cast<uintptr_t>(getCurrentInternal) == 0

#ifdef WEAKS_AVAILABLE
static CallStackUPtr ALWAYS_INLINE getCurrent(int32_t ignoreDepth = 1) {
    if (reinterpret_cast<uintptr_t>(getCurrentInternal) == 0) { //>>>>>>>
        ALOGW("CallStack::getCurrentInternal not linked, returning null");
        return CallStackUPtr(nullptr);
    } else {
        return getCurrentInternal(ignoreDepth);
    }
}

I really need some help about how to get backtrace in processgroup.cpp.