Function walk_pidns_xarray

src/os/linux/sysinfo_more.cpp:111–126

inline VAddr xa_to_node(VAddr e)    { return e & ~3ULL; }

void walk_pidns_xarray(const Engine& eng, u64 xn_slots_off,
                        VAddr entry, std::vector<VAddr>& leaves,
                        std::size_t& budget, int depth = 0) {
    if (entry == 0 || depth > 16) return;
    if (budget == 0) return;   // bound a crafted cyclic/explosive xarray
    --budget;
    if (xa_is_value(entry)) return;
    if (!xa_is_internal(entry)) { leaves.push_back(entry); return; }
    VAddr node = xa_to_node(entry);
    constexpr u64 kSlots = 64;
    std::vector<VAddr> slots(kSlots, 0);
    if (!kva_read(eng, node + xn_slots_off, slots.data(),
                   kSlots * sizeof(VAddr))) return;
    for (u64 i = 0; i < kSlots; ++i)
        if (slots[i]) walk_pidns_xarray(eng, xn_slots_off, slots[i], leaves, budget, depth + 1);
}
} // anonymous

ByteBuf format_pidhashtable(const Engine& eng) {