CETS: Compiler Enforced Temporal Safety for C

Thumbnail Image
Penn collection
Departmental Papers (CIS)
Degree type
Computer Sciences
Grant number
Copyright date
Related resources
Nagarakatte, Santosh
Zhao, Jianzhou

Temporal memory safety errors, such as dangling pointer dereferences and double frees, are a prevalent source of software bugs in unmanaged languages such as C. Existing schemes that attempt to retrofit temporal safety for such languages have high runtime overheads and/or are incomplete, thereby limiting their effectiveness as debugging aids. This paper presents CETS, a compile-time transformation for detecting all violations of temporal safety in C programs. Inspired by existing approaches, CETS maintains a unique identifier with each object, associates this metadata with the pointers in a disjoint metadata space to retain memory layout compatibility, and checks that the object is still allocated on pointer dereferences. A formal proof shows that this is sufficient to provide temporal safety even in the presence of arbitrary casts if the program contains no spatial safety violations. Our CETS prototype employs both temporal check removal optimizations and traditional compiler optimizations to achieve a runtime overhead of just 48% on average. When combined with a spatial-checking system, the average overall overhead is 116% for complete memory safety.

Date of presentation
Conference name
Departmental Papers (CIS)
Conference dates
Conference location
Date Range for Data Collection (Start Date)
Date Range for Data Collection (End Date)
Digital Object Identifier
Series name and number
Volume number
Issue number
Publisher DOI
Journal Issue
Nagarakatte, S., Zhao, J., Martin, M., & Zdancewic, S., CETS: Compiler Enforced Temporal Safety for C, ACM SIGPLAN International Symposium on Memory Management, June 2010, doi: http://doi.acm.org/10.1145/1806651.1806657 © 1994, 1995, 1998, 2002, 2009 by ACM, Inc. Permission to copy and distribute this document is hereby granted provided that this notice is retained on all copies, that copies are not altered, and that ACM is credited when the material is used to form other copyright policies.
Recommended citation