From early design phases to final release, the reliability of modern embedded systems against soft errors should be carefully considered. Several schemes have been proposed to protect embedded systems against soft errors, but they are neither always functional nor robust, even with expensive overhead in terms of hardware area, performance, and power consumption. Thus, system designers need to estimate reliability quantitatively to apply appropriate protection techniques for resource-constrained embedded systems. Vulnerability modeling based on lifetime analysis is one of the most efficient ways to quantify system reliability against soft errors. However, lifetime analysis can be inaccurate, mainly because it fails to comprehensively capture several system-level masking effects. This study analyzes and characterizes microarchitecture-level and software-level masking effects by developing an automated framework with exhaustive fault injections (i.e., soft errors) based on a cycle-accurate gem5 simulator. We injected faults into a register file because errors in the register file can easily be propagated to other components in a processor. We found that only 5% of injected faults can cause system failures on an average over benchmarks, mainly from the MiBench suite. Further analyses showed that 71% of soft errors are overwritten by write operations before being used, and the CPU does not use 20% of soft errors at all after fault injections. The remainder are also masked by several software-level masking effects, such as dynamically dead instructions, compare and logical instructions that do not change the result, and incorrect control flows that do not affect program outputs.

中文翻译：

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表征针对软错误的系统级掩蔽效应

从早期设计阶段到最终发布，现代嵌入式系统针对软错误的可靠性都应该仔细考虑。已经提出了几种方案来保护嵌入式系统免受软错误的影响，但它们既不总是功能性的，也不总是健壮的，即使在硬件面积、性能和功耗方面具有昂贵的开销。因此，系统设计人员需要定量估计可靠性，以便为资源受限的嵌入式系统应用适当的保护技术。基于寿命分析的漏洞建模是针对软错误量化系统可靠性的最有效方法之一。然而，寿命分析可能不准确，主要是因为它未能全面捕捉多个系统级掩蔽效应。本研究通过基于周期精确的 gem5 模拟器开发具有详尽故障注入（即软错误）的自动化框架来分析和表征微架构级和软件级掩蔽效应。我们将错误注入到寄存器文件中，因为寄存器文件中的错误很容易传播到处理器中的其他组件。我们发现，在基准测试中，平均只有 5% 的注入故障会导致系统故障，主要来自 MiBench 套件。进一步的分析表明，71% 的软错误在使用前被写操作覆盖，而 CPU 在注入故障后根本不使用 20% 的软错误。其余部分也被几个软件级屏蔽效果屏蔽，例如动态死指令、不改变结果的比较和逻辑指令，