BACKGROUND

The present technique relates to the field of malicious attacks against computer memory, and the detection and mitigation thereof.

One such malicious attack, known as “rowhammer” or “row hammer”, takes advantage of the physical properties of dynamic random access memory (DRAM), in which charges in a given memory cell can leak to surrounding sells. An attacker can use this charge leakage to change the contents of memory locations that are physically near to an addressed memory row, for example memory locations with a higher privilege level than the memory location that is actually addressed. The attacker can thus corrupt or modify data which it is not permitted to modify, and/or read out data which it is not permitted to access.

There is therefore a desire for methods and apparatus for detecting and mitigating rowhammer attacks.

SUMMARY

At least some examples provide an apparatus comprising:processing circuitry;a cache storage;victim row identification circuitry to:detect a rapid rate of access requests from the processing circuitry to a given row of a dynamic random access memory, DRAM; andresponsive to said detecting, identify at least one victim row associated with said given row, and victim row protection circuitry to copy data stored within said at least one victim row to the cache storage.

Further examples provide a method comprising:detecting a rapid rate of access requests from processing circuitry to a given row of a dynamic random access memory, DRAM;identify at least one victim row associated with said given row; andcopy data stored within said at least one victim row to the cache storage.

Further examples provide an apparatus comprising:processing means;cache storage means;victim row identification means to:detect a rapid rate of access requests from the processing circuitry to a given row of a dynamic random access memory, DRAM; andidentify at least one victim row associated with said given row, andvictim row protection means to copy data stored within said at least one victim row to the cache storage means.

Further aspects, features and advantages of the present technique will be apparent from the following description of examples, which is to be read in conjunction with the accompanying drawings.

