uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Ghost Loads: What is the cost of invisible speculation?
Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication. (Uppsala Architecture Research Team)ORCID iD: 0000-0003-4172-8607
Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication. (Uppsala Architecture Research Team)ORCID iD: 0000-0001-9842-8715
Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication. (Uppsala Architecture Research Team)ORCID iD: 0000-0001-8642-2447
Show others and affiliations
2019 (English)In: Proceedings of the 16th ACM International Conference on Computing Frontiers, New York: ACM Press, 2019, p. 153-163Conference paper, Published paper (Refereed)
Abstract [en]

Speculative execution is necessary for achieving high performance on modern general-purpose CPUs but, starting with Spectre and Meltdown, it has also been proven to cause severe security flaws. In case of a misspeculation, the architectural state is restored to assure functional correctness but a multitude of microarchitectural changes (e.g., cache updates), caused by the speculatively executed instructions, are commonly left in the system.  These changes can be used to leak sensitive information, which has led to a frantic search for solutions that can eliminate such security flaws. The contribution of this work is an evaluation of the cost of hiding speculative side-effects in the cache hierarchy, making them visible only after the speculation has been resolved. For this, we compare (for the first time) two broad approaches: i) waiting for loads to become non-speculative before issuing them to the memory system, and ii) eliminating the side-effects of speculation, a solution consisting of invisible loads (Ghost loads) and performance optimizations (Ghost Buffer and Materialization). While previous work, InvisiSpec, has proposed a similar solution to our latter approach, it has done so with only a minimal evaluation and at a significant performance cost. The detailed evaluation of our solutions shows that: i) waiting for loads to become non-speculative is no more costly than the previously proposed InvisiSpec solution, albeit much simpler, non-invasive in the memory system, and stronger security-wise; ii) hiding speculation with Ghost loads (in the context of a relaxed memory model) can be achieved at the cost of 12% performance degradation and 9% energy increase, which is significantly better that the previous state-of-the-art solution.

Place, publisher, year, edition, pages
New York: ACM Press, 2019. p. 153-163
Keywords [en]
speculation, security, side-channel attacks, caches
National Category
Computer Sciences
Identifiers
URN: urn:nbn:se:uu:diva-383173DOI: 10.1145/3310273.3321558ISI: 000474686400019ISBN: 978-1-4503-6685-4 (print)OAI: oai:DiVA.org:uu-383173DiVA, id: diva2:1314992
Conference
CF 2019, April 30 – May 2, Alghero, Sardinia, Italy
Funder
Swedish Research Council, 2015-05159Swedish National Infrastructure for Computing (SNIC)
Note

Available from: 2019-05-10 Created: 2019-05-10 Last updated: 2019-08-23Bibliographically approved

Open Access in DiVA

fulltext(1630 kB)78 downloads
File information
File name FULLTEXT01.pdfFile size 1630 kBChecksum SHA-512
24303151119c92f40922958096637d692a187cd8717801867d30382639704cdcabdd74cda8e5d836995fcd1705cbf635e035096699f8f9130ff89eecd2ac8932
Type fulltextMimetype application/pdf

Other links

Publisher's full text

Authority records BETA

Sakalis, ChristosAlipour, MehdiJimborean, AlexandraKaxiras, StefanosSjälander, Magnus

Search in DiVA

By author/editor
Sakalis, ChristosAlipour, MehdiRos, AlbertoJimborean, AlexandraKaxiras, StefanosSjälander, Magnus
By organisation
Computer Architecture and Computer Communication
Computer Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 78 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
isbn
urn-nbn

Altmetric score

doi
isbn
urn-nbn
Total: 78 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf