<p><em>With the advent of huge multicore processors, complex hardware, intermingled networks and huge disk storage capabilities the programs that are used in the system and the code which is written to control them are increasingly getting large and often much complicated. There is increase in need of a framework which tracks issues, debugs the program, helps to analyze the reason behind degradation of system and program performance. Another big concern for deploying such a framework in complex systems is to the footprint of the framework upon the setup. LTTng project aims to provide such an effective tracing and debugging toolset for Linux systems. Our work is to measure the effectiveness of LTTng in a Multicore Environment and evaluate its affect on the system and program performance. We incorporate Control and Data Flow analysis of the system and the binaries of LTTng to reach for a conclusion.</em></p>

With the advent of huge multicore processors, complex hardware, intermingled networks and huge disk storage capabilities the programs that are used in the system and the code which is written to control them are increasingly getting large and often much complicated. There is increase in need of a framework which tracks issues, debugs the program, helps to analyze the reason behind degradation of system and program performance. Another big concern for deploying such a framework in complex systems is to the footprint of the framework upon the setup. LTTng project aims to provide such an effective tracing and debugging toolset for Linux systems. Our work is to measure the effectiveness of LTTng in a Multicore Environment and evaluate its affect on the system and program performance. We incorporate Control and Data Flow analysis of the system and the binaries of LTTng to reach for a conclusion.

One recent innovation in the networking industry, is the concept of Network FunctionVirtualization (NFV). NFV is based on a networking paradigm in which network functions,which have typically been implemented in the form of dedicated hardware appliances in thepast, are implemented in software and deployed on commodity hardware using modernvirtualization techniques. While the most common approach is to place each virtual networkfunction in a virtual machine - using hardware-level virtualization – the growing influenceand popularity of Docker and other container-based solutions has naturally led to the idea ofcontainerized deployments. This is a promising concept, as containers (or operating systemlevel virtualization) can offer a flexible and lightweight alternative to hardware-levelvirtualization, with the ability to use the resources of the host directly. The main problem withthis concept, is the fact that the default behavior of Docker and similar technologies is to relyon the networking stack of the host, which typically isn’t performant enough to handle theperformance requirements associated with NFV. In this dissertation, an attempt is made toevaluate the feasibility of using userspace networking to accelerate the network performanceof Docker containers, bypassing the standard Linux networking stack by moving the packetprocessing into userspace.

Software systems are becoming increasingly bloated to accommodate a wide array of features, platforms and users. This results not only in wastage of memory but also in an increase in their attack surface. Existing works broadly use binary-rewriting techniques to remove unused code, but this results in a binary that is highly customized for a given usage context. If the usage scenario of the binary changes, the binary has to be regenerated. We present DYNACUT– a framework for Dynamic and Adaptive Code Customization. DYNACUT provides the user with the capability to customize the application to changing usage scenarios at runtime without the need for the source code. DYNACUT achieves this customization by leveraging two techniques: 1) identifying the code to be removed by using execution traces of the application and 2) by rewriting the process dynamically. The first technique uses traces of the wanted features and the unwanted features of the application and generates their diffs to identify the features to be removed. The second technique modifies the process image to add traps and fault-handling code to remove vulnerable but unused code. DYNACUT can also disable temporally unused code – code that is used only during the initialization phase of the application. To demonstrate its effectiveness, we built a prototype of DYNACUT and evaluated it on 9 real-world applications including NGINX, Lighttpd and 7 applications of the SPEC Intspeed benchmark suite. DYNACUT removes upto 56% of executed basic blocks and upto 10% of the application code when used to remove initialization code. The total overhead is in the range of 1.63 seconds for Lighttpd, 4.83 seconds for NGINX and about 39 seconds for perlbench in the SPEC suite. / Master of Science / Software systems are becoming increasingly bloated to accommodate a wide array of users, features and platforms. This results in the software not only occupying extra space on com- puting platforms but also in an increase in the ways that the applications can be exploited by hackers. Current works broadly use a variety of techniques to identify and remove this type of vulnerable and unused code. But, these approaches result in a software that has to be modified with the changing usage scenarios of the application. We present DYNACUT, a dynamic code customization tool that can customize the application at its runtime with a minimal overhead. We use the execution traces of the application to customize the ap- plication according to user specifications. DYNACUT can identify code that is only used in the initial stages of the application execution (initialization code) and remove them. DYNA- CUT can also disable features of the application. To demonstrate its effectiveness, we built a prototype of DYNACUT and evaluated it on 9 real-world applications including NGINX, Lighttpd and 7 applications of the SPEC Intspeed benchmark suite. DYNACUT removes upto 56% of executed basic blocks and upto 10% of the application code when used to remove initialization code. The total overhead is in the range of 1.63 seconds for Lighttpd, 4.83 seconds for NGINX and about 39 seconds for perlbench in the SPEC suite.

A detailed walkthrough of the engineering process for the development of an accessible search engine tool. Contributions include a comprehensive literature review, assumptions, requirements, high-level design, implementation, and usability evaluations. / The internet has become useful in just about anything we do. Unfortunately, as vision degrades so does our ability to perceive the web. The design of Graphical User Interfaces (GUIs) has become overwhelmingly common and is meant to be coupled with a screen and mouse. The interface introduced in this thesis was developed to avoid graphically driven design and create a novel Search Engine interface intended for blind and low vision users. This is achieved by minimizing the total concern of the user (the userspace) to a handful of options and a predetermined structure to the Search Engine Results Page (SERP). This thesis describes the entire development process starting from the literature review and including implementation, evaluation, and future work. / Thesis / Master of Applied Science (MASc)

This thesis deals with technologies of SELinux security policy writing. Furthermore the thesis analyzes userspace of GNU/Linux operating system with special focus on KDE desktop environment. On the basis of this analysis a bottom-up methodics to create a security policy is devised. Acquired knowledge is then used in practice when realizing the main goal of the thesis, which is to create example security policies for chosen KDE applications. When describing technologies of security policy writing the thesis draws information from available sources of information. Input for userspace analysis are available electronic sources of information and author's own experience with analyzed applications. This is used with common philosophic principles to devise bottom-up methodics of policy writting. Following act of policy building draws from defined security goals, acquired knowledge, created methodics and defined usecases. Theoretical contribution of the thesis is devised methodics of userspace policy building. Main practical contribution are then created example SELinux policies for chosen KDE applications. The structure of the thesis follows its goals. For them three parts are created: background research of available resources, author's own theoretical contemplations and practical output of the thesis. Those parts are then devided into sections according to needs of each topic.