一句话:提出 MERR,通过将页表子树嵌入持久内存对象,显著降低挂载/卸载开销,从而缩短内存暴露时间。
本文针对非易失性内存(NVM)上长期存活的持久内存对象(PMO)提出内存防御技术 MERR。它通过减少 PMO 挂载/卸载到内存空间的开销来缩短内存暴露时间:将页表子树嵌入 PMO,以降低地址随机化等防御机制切换的开销。论文还讨论了该技术对权限控制和硬件实现带来的复杂性并给出解决方案。实验显示,MERR 在 5% 时间开销下将暴露时间减少 60%,在 10.9% 开销下减少 70%,并使地址随机化周期从秒级缩短至 41.4us 以下,展示了增强内存安全的潜力。
This paper proposes a new defensive technique for memory, especially useful for long-living objects on Non-Volatile Memory (NVM), or called Persistent Memory objects (PMOs). The method takes a distinctive perspective, trying to reduce memory exposure time by largely shortening the overhead in attaching and detaching PMOs into the memory space. It does it through a novel idea, embedding page table subtrees inside PMOs. The paper discusses the complexities the technique brings, to permission controls and hardware implementations, and provides solutions. Experimental results show that the new technique reduces memory exposure time by 60% with a 5% time overhead (70% with 10.9% overhead). It allows much more frequent address randomizations (shortening the period from seconds to less than 41.4us), offering significant potential for enhancing memory security.