Computer Science | Grinnell College

On Thursday, October 11, Mattori Birnbaum, Linh Bui, Zoe Grubbs, Hadley Luker, and Xinya Yang will give a talk on their summer 2018 Mentored Advanced Project:

Identifying performance problems in code is crucial for software developers. Even small inefficiencies can incur large costs in complex, long-running systems. While programmers can tune their programs by using efficient algorithms and data structures, hardware resources such as caches and branch predictors can still be a major source of inefficiency. Such inefficient uses of hardware resources are rarely obvious in the program's source code.

During summer 2018, we developed a tool called AnaLysis of EXecution (ALEX) to help developers diagnose performance problems. ALEX gathers and displays performance data from unmodified programs run on GNU/Linux. Our visualization helps developers quickly find patterns of poor performance, and the accompanying analysis leads developers to the relevant source code. In our talk, we will demonstrate how ALEX can help developers, explain how it works, and discuss our summer research experience.

At 4:00 p.m., refreshments will be served in the Computer Science Commons. The talk, "Finding Performance Problems with ALEX," will begin at 4:15 p.m. in Noyce 3821. Everyone is welcome to attend!

We will discuss a recent report from Bloomberg about a security breach in the hardware supply chain for servers used by almost 30 major US-based companies. Bloomberg’s reporting suggests that a group within the Chinese government’s intelligence agency were able to add a small chip to motherboards manufactured for SuperMicro, a major server hardware supplier in the US. These chips apparently inject malicious code into the server’s operating system, allowing hackers to remotely access compromised servers and bypass security controls within the operating system. We will discuss the mechanisms used to carry out these attacks, the differences between hardware- and software-based exploits, consider the impacts of such an attack, and discuss possible ways to mitigate attacks like this one in the future.

Readings include Bloomberg's original reporting (The Big Hack: How China Used a Tiny Chip to Infiltrate U.S. Companies, J. Robertson and M. Riley, Bloomberg Businessweek, 4 Oct 2018) and two articles providing some additional perspective on this story, which has not yet been independently confirmed (The China SuperMicro Hack: About That Bloomberg Report, N. Weaver, Lawfare, 4 Oct 2018, and Decoding the Chinese SuperMicro super spy-chip scandal: What do we know – and who is telling the truth? K. McCarthy, The Register, 4 Oct 2018.)

Computer science table (CS Table) is a weekly meeting of Grinnell College community members (students, faculty, staff, etc.) interested in discussing topics related to computing and computer science. CS Table meets Tuesdays from 12:00–12:45pm in JRC 224C (inside the Marketplace). Contact the CS faculty for the weekly reading. Students on meal plans, faculty, and staff are expected to cover the cost of their meals. Visitors to the College and students not on meal plans can charge their meals to the department (sign in at the Marketplace front desk).

On Thursday, March 3, Forrest Friesen 2011 will give a talk in the “Thursday Extras” series:

Field-programmable gate arrays are integrated circuits whose internal structure can be configured to create digital logic at the lowest level. With ever-improving semiconductor manufacturing technology and increasingly accessible configuration tools, they are the ultimate in general purpose computational hardware. This talk will present an overview of working with modern FPGAs, with examples taken from my independent study project in the physics department. I will also discuss the devices from a technology studies perspective.

Refreshments will be served at 4:15 p.m. in the Computer Science Commons (Noyce 3817). Mr. Friesen's talk, “Computation in pure hardware with FPGAs,” will follow at 4:30 p.m. in Noyce 3821. Everyone is welcome to attend!