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A comment on ECC matters. Parent comment

Re:ECC matters by theevilsharpie on Sunday January 03, 2021 @01:27PM (#25623734)
ECC isn't a direct mitigation against Rowhammer attacks, as memory errors caused by three or more flipped bits would still go undetected (unless you're using ChipKill, but that's a rare setup).

However, flipped three bits simultaneously isn't trivial, and the attempts that flip fewer bits will be detected and logged.

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Re:ECC matters by GregarianChild on Sunday January 03, 2021 @02:24PM (#25624329)
Isn't ChipKill just another form of ECC? If so there is a number of bitflips that ChipKill can no longer correct / detect. [1] seems to say that they observed some flips in dRAM with ChipKill, although the paper is a bit vague here.

[1] B. Schroeder et al, DRAM Errors in the Wild: A Large-Scale Field Study http://www.cs.toronto.edu/~bianca/papers/sigmetrics09.pdf

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Re:ECC matters by rajesh-s on Sunday January 03, 2021 @02:22PM (#25624302)
Right! Section 1.3 of this publication discusses possible mitigations for the row hammer problem and where ECC fits in

https://users.ece.cmu.edu/~omutlu/pub/rowhammer-summary.pdf

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Re:ECC matters by GregarianChild on Sunday January 03, 2021 @02:27PM (#25624353)
The paper you cite is from 2014 and the mitigations discussed there have all been circumvented. [1] is from 2020 and a better read for Rowhammer mitigation.

[1] J. S. Kim et al, Revisiting RowHammer: An Experimental Analysis of Modern DRAM Devices and Mitigation Techniques https://arxiv.org/abs/2005.13121

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Re:ECC matters by rajesh-s on Sunday January 03, 2021 @02:36PM (#25624431)
Thanks for pointing that out!
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