Method walkFP

src/stackWalker.cpp:65–112

int StackWalker::walkFP(void* ucontext, const void** callchain, int max_depth) {
    const void* pc;
    uintptr_t fp;
    uintptr_t sp;
    uintptr_t bottom = (uintptr_t)&sp + MAX_WALK_SIZE;

    StackFrame frame(ucontext);
    if (ucontext == NULL) {
        pc = callerPC();
        fp = (uintptr_t)callerFP();
        sp = (uintptr_t)callerSP();
    } else {
        pc = (const void*)frame.pc();
        fp = frame.fp();
        sp = frame.sp();
    }

    int depth = 0;

    // Walk until the bottom of the stack or until the first Java frame
    while (depth < max_depth) {
        if (CodeHeap::contains(pc) && !(depth == 0 && frame.unwindAtomicStub(pc))) {
            break;
        }

        callchain[depth++] = pc;

        // Check if the next frame is below on the current stack
        if (fp < sp || fp >= sp + MAX_FRAME_SIZE || fp >= bottom) {
            break;
        }

        // Frame pointer must be word aligned
        if (!aligned(fp)) {
            break;
        }

        pc = stripPointer(SafeAccess::load((void**)fp + FRAME_PC_SLOT));
        if (inDeadZone(pc)) {
            break;
        }

        sp = fp + (FRAME_PC_SLOT + 1) * sizeof(void*);
        fp = *(uintptr_t*)fp;
    }

    return depth;
}

int StackWalker::walkDwarf(void* ucontext, const void** callchain, int max_depth) {
    const void* pc;