Simply-Track-and-Refresh: Efficient and Scalable Rowhammer Mitigation
Rowhammer is a memory vulnerability that can compromise system-level security. Rowhammer occurs when a DRAM row is accessed repeatedly, potentially causing bit-flips for neighboring rows. The threshold for Rowhammer has decreased from 139K accesses in 2014 to 3.2K in 2022. This threshold is projected to decrease further. Many existing solutions are not scalable, incur high overhead, or fail to offer protection in realistic scenarios. We propose Simply-Track-And-Refresh (STAR) as an effective and scalable Rowhammer mitigation. We compare STAR's performance overhead to recent solutions, HYDRA and AQUA. At ultra-low thresholds (500), STAR introduces 9.5x/31.7x lower average execution time overhead than HYDRA/AQUA. In addition, STAR introduces up to 4.3x lower area overhead and up to 3.3x lower power consumption compared to HYDRA and AQUA. We present proof of correctness, area and power consumption results derived using CACTI, and evaluation results from the PARSEC, SPLASH-2, SPEC2006, SPEC2017, and PAMPAR benchmark suites.
