1 / 16

Thread-Safe Dynamic Binary Translation using Transactional Memory

Thread-Safe Dynamic Binary Translation using Transactional Memory. JaeWoong Chung, Michael Dalton, Harri Kannan and Christos Kozyrakis (HPCA 2008). LBA reading group 02/07/2008 by Evangelos Vlachos. Introduction. Wide spectrum of DBT applicability

farren
Download Presentation

Thread-Safe Dynamic Binary Translation using Transactional Memory

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Thread-Safe Dynamic Binary Translation using Transactional Memory JaeWoong Chung, Michael Dalton, Harri Kannan and Christos Kozyrakis (HPCA 2008) LBA reading group 02/07/2008 by Evangelos Vlachos

  2. Introduction • Wide spectrum of DBT applicability • Debugging, Cross-ISA binary compatibility, etc. • Poor support for multithreaded applications • Data races on metadata • Solutions given so far • Not supported • Locking • Serialization of application’s threads

  3. Introduction • Solution proposed • DBT with transactional memory to eliminate metadata races • Implemented a DBT framework that runs DIFT on multithreaded applications

  4. Overview • DBT & DIFT overview • DBT & TM = Thread-Safe DBT • Optimazations for DBT Transactions • DIFT prototype • Evaluation • Conclusion

  5. Metadata Races False negative False positive • Introduction of metadata breaks atomicity of RMW instructions • Attackers may introduce race conditions to exploit memory safety vulnerabilities

  6. DBT + TM • Different flavors of TM • STM, Hybrid STM, HTM • Many issues to consider and many trade-offs …to be continued

  7. DBT + TM • Software & Hybrid TM • High overhead – Barriers required for every access • Transaction Length • Basic block boundaries? • Indirect branches?

  8. DBT + TM • User level transactions • Requires nesting of transactions • Avoid partial overlap of transactions • User level sync • If span multiple blocks problem  • Solution: • Detect • Re-instrument • Re-optimize for basic blocks

  9. DBT + TM optimizations • Length & cost of starting a transaction • DBT trace granularity • Limited length • Cost only at start & end of the trace • Dynamic transaction merging • At Tx_End check if work amortizes cost • Some additional cost when merging • Longer transactions

  10. DBT + TM optimizations • Limit the use of barriers • Conflict detection & Data Versioning • Categorize accesses • During trace generation • Dynamically

  11. DIFT prototype • Software TM system • Based on Pin • 210 locks  word version encoded also • Software checkpoint provided by Pin • RD_barrier(), WR_barrier(), WRlocal_barrier() • Transaction length = DBT trace • All other systems emulated!!! ☺

  12. Evaluation • Compared to the same DIFT tool without transactions (not thread-safe)

  13. Evaluation • Effect of Transaction Length • Additional overhead to base case TM system

  14. Evaluation • Effect of access categorization

  15. Evaluation • Effect of Hardware Support for Transactions

  16. Conclusion • First system to truly support parallel monitoring • Based on TM to resolve metadata races • Based on DBT • High Overhead due to DBT

More Related