24,392 research outputs found
Compiling Exceptions Correctly
Exceptions are an important feature of modern programming languages, but their compilation has traditionally been viewed as an advanced topic. In this article we show that the basic method of compiling exceptions using stack unwinding can be explained and verified both simply and precisely, using elementary functional programming techniques. In particular, we develop a compiler for a small language with exceptions, together with a proof of its correctness
Validation of a software dependability tool via fault injection experiments
Presents the validation of the strategies employed in the RECCO tool to analyze a C/C++ software; the RECCO compiler scans C/C++ source code to extract information about the significance of the variables that populate the program and the code structure itself. Experimental results gathered on an Open Source Router are used to compare and correlate two sets of critical variables, one obtained by fault injection experiments, and the other applying the RECCO tool, respectively. Then the two sets are analyzed, compared, and correlated to prove the effectiveness of RECCO's methodology
The computerization of programming: Ada (R) lessons learned
One of the largest systems yet written in Ada has been constructed. This system is the Intermetrics Ada compiler. Many lessons have been learned during the implementation of this Ada compiler. Some of these lessons, concentrating on those lessons relevant to large system implementations are described. The characteristics of the Ada compiler implementation project at Intermetrics are also described. Some specific experiences during the implementation are pointed out
Induction of First-Order Decision Lists: Results on Learning the Past Tense of English Verbs
This paper presents a method for inducing logic programs from examples that
learns a new class of concepts called first-order decision lists, defined as
ordered lists of clauses each ending in a cut. The method, called FOIDL, is
based on FOIL (Quinlan, 1990) but employs intensional background knowledge and
avoids the need for explicit negative examples. It is particularly useful for
problems that involve rules with specific exceptions, such as learning the
past-tense of English verbs, a task widely studied in the context of the
symbolic/connectionist debate. FOIDL is able to learn concise, accurate
programs for this problem from significantly fewer examples than previous
methods (both connectionist and symbolic).Comment: See http://www.jair.org/ for any accompanying file
ret2spec: Speculative Execution Using Return Stack Buffers
Speculative execution is an optimization technique that has been part of CPUs
for over a decade. It predicts the outcome and target of branch instructions to
avoid stalling the execution pipeline. However, until recently, the security
implications of speculative code execution have not been studied.
In this paper, we investigate a special type of branch predictor that is
responsible for predicting return addresses. To the best of our knowledge, we
are the first to study return address predictors and their consequences for the
security of modern software. In our work, we show how return stack buffers
(RSBs), the core unit of return address predictors, can be used to trigger
misspeculations. Based on this knowledge, we propose two new attack variants
using RSBs that give attackers similar capabilities as the documented Spectre
attacks. We show how local attackers can gain arbitrary speculative code
execution across processes, e.g., to leak passwords another user enters on a
shared system. Our evaluation showed that the recent Spectre countermeasures
deployed in operating systems can also cover such RSB-based cross-process
attacks. Yet we then demonstrate that attackers can trigger misspeculation in
JIT environments in order to leak arbitrary memory content of browser
processes. Reading outside the sandboxed memory region with JIT-compiled code
is still possible with 80\% accuracy on average.Comment: Updating to the cam-ready version and adding reference to the
original pape
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