Der Vortrag beschreibt Stand, Entwicklung und Realisierung der Virtualisierungsinfrastruktur am Universitätsrechenzentrum der TU-Chemnitz in Form einer technischen Sicht.

Τα ενσωματωμένα υπολογιστικά συστήματα έχουν αρχίσει να χρησιμοποιούνται ολοένα και περισσότερο τα τελευταία χρόνια, όχι μόνο σε βιομηχανικές ή άλλες εξεζητημένες εφαρμογές αλλά και στην καθημερινότητα μας. Αυτό οφείλεται στο γεγονός ότι η συγκεκριμένη τεχνολογία είναι φτηνότερη, ευέλικτη και λιγότερο ενεργοβόρος σε σχέση με τα αντίστοιχα ηλεκτρονικά κυκλώματα που χρησιμοποιούνταν παλιότερα. Η παρούσα διπλωματική εργασία περιγράφει αναλυτικά τη διαδικασία για τη σωστή ρύθμιση του συστήματος μας και την μεταγλώττιση (compilation) του πυρήνα του Linux προκειμένου να τρέχει χωρίς προβλήματα πάνω στην FPGA πλακέτα της Xilinx, Virtex 5. Σαν επεξεργαστή επιλέξαμε να χρησιμοποιήσουμε τον soft - core επεξεργαστή της Xilinx microblaze,προσθέτοντας σαν επιπλέον περιφερειακά την οθόνη TFT καθώς και την θύρα PS/2. Στη συνέχεια προκειμένου να καταδείξουμε τις δυνατότητες που έχει το σύστημα που “χτίσαμε”, εγκαταστήσαμε γραφικό περιβάλλον με ορισμένες εφαρμογές και εκτελούμε κρυπτογραφικές συναρτήσεις από το terminal του λειτουργικού μας. / The embedded computer systems have recently started to be present in a number of implementations, not only in the industrial setting but also in normal life applications. This is due to the fact that this particular technology is cheaper, more efficient and less power - consuming than its dedicated electronic counterparts. In this diploma thesis we will study the process for the proper configuration of our system and the compilation of Linux Kernel in order to have a completely functional embedded system on the Xilinx' s FPGA board, Virtex 5. We used the Microblaze soft - core processor and we added the TFT monitor and the PS/2 port as extra components to our system. Furthermore in order to present the capabilities of our system, we added the Nano - X graphical user interface and we run cryptographic algorithms through the terminal of the operating system.

Modern network interface controllers allow the host to offload packet processing to hardware in order to improve performance. At the present time, the advanced features are utilized in the Linux kernel by offloading the Traffic Control subsystem. Since this subsystem has been designed for a completely different purpose, its usage for hardware offloading is impractical and unreliable. Furthermore, in its current state the subsystem is not capable of utilizing all hardware features, which are often poorly documented. The presented work adopts a different approach to the problem. Five high-end controllers and their packet-processing pipelines were examined in detail. Accounting for their projected future development, common traits and features were identified. The researched information was used to draft a proposal for a new Linux subsystem, more compatible with hardware offloading than the current solution. The proposed subsystem defines a sufficiently descriptive interface to utilize the majority of hardware-offloaded features while avoiding common problems caused by excessively generalized approach of Traffic Control.

Dans cette thèse nous nous intéressons à intégrer dans la distribution Linux produite par Mandriva une assurance qualité permettant de proposer des garanties de propriétés sur le code exécuté. Le processus de création d’une distribution implique l’utilisation de logiciels de provenances diverses pour proposer un assemblage cohérent et présentant une valeur ajoutée pour l’utilisateur. Ceci engendre une moindre maîtrise potentielle sur le code. Un audit manuel permet de s’assurer que celui-Ci présente de bonnes propriétés, par exemple, en matière de sécurité. Le nombre croissant de composants à intégrer, et la croissance de la quantité de code de chacun amènent à avoir besoin d’outils pour permettre une assurance qualité. Après une étude de la distribution nous choisissons de nous concentrer sur un paquet critique, le noyau Linux : nous proposons un état de l’art des méthodes de vérifications appliquées à ce contexte particulier, et identifions le besoin d’améliorer la compréhension de la structure du code source, la question de l’explosion combinatoire et le manque d’intégration des outils d’analyse de l’état de l’art. Pour répondre à ces besoins nous proposons une représentation du code source sous la forme d’un graphe, et l’utilisons pour aider à la documentation et à la compréhension de l’architecture du code. Des méthodes de détection de communautés sont évaluées sur ce cas pour répondre au besoin de l’explosion combinatoire. Enfin nous proposons une architecture intégrée dans le système de construction de la distribution permettant d’intégrer des outils d’analyse et de vérification de code. / In this thesis we are interested in integrating to the Linux distribution produced by Mandriva quality assurance level that allows ensuring user-Defined properties on the source code used. The core work of a distribution and its producer is to create a meaningful aggregate from software available. Those softwares are free and open source, hence it is possible to adapt it to improve end user’s experience. Hence, there is less control over the source code. Manual audit can of course be used to make sure it has good properties. Examples of such properties are often referring to security, but one could think of others. However, more and more software are getting integrated into distributions and each is showing an increase in source code volume: tools are needed to make quality assurance achievable. We start by providing a study of the distribution itself to document the current status. We use it to select some packages that we consider critical, and for which we can improve things with the condition that packages which are similar enough to the rest of the distribution will be considered first. This leads us to concentrating on the Linux kernel: we provide a state of the art overview of code verification applied to this piece of the distribution. We identify a need for a better understanding of the structure of the source code. To address those needs we propose to use a graph as a representation of the source code and use it to help document and understand its structure. Specifically we study applying some state of the art community detection algorithm to help handle the combinatory explosion. We also propose a distribution’s build system-Integrated architecture for executing, collecting and handling the analysis of data produced by verifications tools.

Submitted by Biblioteca do Instituto de Física (bif@ndc.uff.br) on 2017-03-07T17:45:47Z No. of bitstreams: 1 tese_orahcio_versao_final.pdf: 11835533 bytes, checksum: c59bd8a0580c4b81b9b9e33a4c9536a0 (MD5) / Made available in DSpace on 2017-03-07T17:45:47Z (GMT). No. of bitstreams: 1 tese_orahcio_versao_final.pdf: 11835533 bytes, checksum: c59bd8a0580c4b81b9b9e33a4c9536a0 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico / A tese apresenta em sua primeira parte o estudo de uma dinâmica aplicada a fluxos em uma rede regular quadrada, que tem características semelhantes a um processo estocástico de reações de partícula única, como reações de difusão, coalescência e criação de partículas. Utilizamos uma aproximação de campo médio para obtermos a solução analítica das distribuições de fluxos estacionárias. Essa solução concorda em boa aproximação com nossas simulações numéricas para o mesmo modelo. Na segunda parte é apresentada a estrutura de comunidades de um sistema real definido pelo sistema operacional livre Debian GNU/Linux. Estudamos a estrutura geral da rede de pacotes da última versão estável desse sistema e a estrutura de comunidades, comparando essas subestruturas com as divisões pré-estabelecidas pelos desenvolvedores desse sistema. Propusemos um método para agrupar desenvolvedores individuais em grupos que maximizam as relações de dependência entre os pacotes por eles desenvolvidos. / The first part of this thesis shows a study of flow dynamics applied on directed regular network, which presents similar features of single particle reaction process, with diffusion, coalescence and branching reactions. We obtained a solution by mean field approach for the steady distribution of flows, that presents a good agreement with our numerical simulations. In the second part, it is presented the community structure of the real system defined by the Debian GNU/Linux free operating system. We studied the general structure of the packages network on the last steady release and the substructures of communities, the emergence of these ones and the relation between the maintainers groups of these packages. We propose a method for grouping individual maintainers that maximizes the number of dependency relations per group.

The use of internet has increased over the past years. Many users may not have good intentions. Some people use the internet to gain access to the unauthorized information. Although absolute security of information is not possible for any network connected to the Internet however, firewalls make an important contribution to the network security. A firewall is a barrier placed between the network and the outside world to prevent the unwanted and potentially damaging intrusion of the network. This thesis compares the performance of Linux packet filtering firewalls, i.e. iptables and shorewall. The firewall performance testing helps in selecting the right firewall as needed. In addition, it highlights the strength and weakness of each firewall. Both firewalls were tested by using the identical parameters. During the experiments, recommended benchmarking methodology for firewall performance testing is taken into account as described in RFC 3511. The comparison process includes experiments which are performed by using different tools. To validate the effectiveness of firewalls, several performance metrics such as throughput, latency, connection establishment and teardown rate, HTTP transfer rate and system resource consumption are used. The experimental results indicate that the performance of Iptables firewall decreases as compared to shorewall in all the aspects taken into account. All the selected metrics show that large numbers of filtering rules have a negative impact on the performance of both firewalls. However, UDP throughput is not affected by the number of filtering rules. The experimental results also indicate that traffic sent with different packet sizes do not affect the performance of firewalls. / Muhammad Zeeshan Ahmad: +46-700228942

CrossDump is a GPS application developed for modern industrial vehicles, specifically those in municipal solid waste collection. The application is developed for CrossControl AB, a company selling computers and electronics for heavy machinery and industrial trucks. CrossDump will be used to demonstrate the potential of CrossControl’s display computers. In contrast to GPS applications like Google Maps, CrossDump is tailor-made for CrossControl’s displays, mounted on the dashboard by the driver in a vehicle. The system helps garbage truck drivers navigate safely and efficiently between waste collection sites and supplies location-specific information relevant to the driver’s work tasks. CrossDump is built to minimize the driving distance, which contributes to a more sustainable environment. To show the full capacity of CrossControl’s hardware the application has been designed specifically with performance in mind. / CrossDump är en GPS-applikation utvecklad för moderna industrifordon, specifikt de inom kommunal avfallshantering. Applikationen är skapad åt CrossControl AB, ett företag som säljer datorer och elektronik till industriella fordon och maskiner. CrossDump kan demonstrera potentialen hos CrossControls displaydatorer. Till skillnad från GPS-applikationer som Google Maps, är CrossDump skräddarsydd för CrossControls displayer, som kan monteras framme vid föraren i ett fordon. Applikationen hjälper sopbilsförare att navigera tryggt och effektivt mellan sopplatser och visar platsbaserad information om vilka uppgifter föraren ska utföra. CrossDump är byggd för att minimera förarens körsträcka för att bidra till en mer hållbar miljö. För att utveckla ett system som visar hårdvarans förmåga har applikationen designats specifikt med prestanda i åtanke.

Lorsqu'une erreur survient dans le noyau Linux, celui-ci émet un rapport d’erreur appelé "kernel oops" contenant le contexte d’exécution de cette erreur. Les kernel oops décrivent des erreurs réelles de Linux, permettent de classer les efforts de débogage par ordre de priorité et de motiver la conception d’outils permettant d'améliorer la fiabilité du code de Linux. Néanmoins, les informations contenues dans un kernel oops n’ont de sens que si elles sont représentatives et qu'elles peuvent être interprétées correctement. Dans cette thèse, nous étudions une collection de kernel oops provenant d'un dépôt maintenu par Red Hat sur une période de huit mois. Nous considérons l’ensemble des caractéristiques de ces données, dans quelle mesure ces données reflètent d’autres informations à propos de Linux et l’interprétation des caractéristiques pouvant être pertinentes pour la fiabilité de Linux. Nous constatons que ces données sont bien corrélées à d’autres informations à propos de Linux, cependant, elles souffrent parfois de problèmes de duplication et de manque d’informations. Nous identifions également quelques pièges potentiels lors de l'étude des fonctionnalités, telles que les causes d'erreurs fréquentes et les causes d'applications défaillant fréquemment. En outre, un kernel oops fournit des informations précieuses et de première main pour un mainteneur du noyau Linux lui permettant d'effectuer le débogage post-mortem car il enregistre l’état du noyau Linux au moment du crash. Cependant, le débogage sur la seule base des informations contenues dans un kernel oops est difficile. Pour aider les développeurs avec le débogage, nous avons conçu une solution afin d'obtenir la ligne fautive à partir d’un kernel oops, i.e., la ligne du code source qui provoque l'erreur. Pour cela, nous proposons un nouvel algorithme basé sur la correspondance de séquences approximative utilisé dans le domaine de bioinformatique. Cet algorithme permet de localiser automatiquement la ligne fautive en se basant sur le code machine à proximité de celle-ci et inclus dans un kernel oops. Notre algorithme atteint 92% de précision comparé à 26 % pour l’approche traditionnelle utilisant le débogueur gdb. Nous avons intégré notre solution dans un outil nommé OOPSA qui peut ainsi alléger le fardeau pour les développeurs lors du débogage de kernel oops. / When a failure occurs in the Linux kernel, the kernel emits an error report called “kernel oops”, summarizing the execution context of the failure. Kernel oopses describe real Linux errors, and thus can help prioritize debugging efforts and motivate the design of tools to improve the reliability of Linux code. Nevertheless, the information is only meaningful if it is representative and can be interpreted correctly. In this thesis, we study a collection of kernel oopses over a period of 8 months from a repository that is maintained by Red Hat. We consider the overall features of the data, the degree to which the data reflects other information about Linux, and the interpretation of features that may be relevant to reliability. We find that the data correlates well with other information about Linux, but that it suffers from duplicate and missing information. We furthermore identify some potential pitfalls in studying features such as the sources of common faults and common failing applications. Furthermore, a kernel oops provides valuable first-hand information for a Linux kernel maintainer to conduct postmortem debugging, since it logs the status of the Linux kernel at the time of a crash. However, debugging based on only the information in a kernel oops is difficult. To help developers with debugging, we devised a solution to derive the offending line from a kernel oops, i.e., the line of source code that incurs the crash. For this, we propose a novel algorithm based on approximate sequence matching, as used in bioinformatics, to automatically pinpoint the offending line based on information about nearby machine-code instructions, as found in a kernel oops. Our algorithm achieves 92% accuracy compared to 26% for the traditional approach of using only the oops instruction pointer. We integrated the solution into a tool named OOPSA, which would relieve some burden for the developers with the kernel oops debugging.

This thesis is focused on design and implementation of toolchain for compilation and installation of RPM packages from SRPM packages in Fedora Linux distribution. Tools can be set up to modify compiler options and rpm macros. A tool for custom compilation of Linux kernel was also implemented. This tool builds the kernel with default options or according to configuration supplied by user. The toolchain was used to create customized distribution. Resulting distribution contains these tools for compilation and installation of additional software.

I det här arbetet har en emulator till DeLavals inbyggda system IOM 200 utvecklats i en Linuxmiljö. Konceptet har varit att implementera en emulator i DeLavals testprocess för mjukvaran i ett inbyggt system. Syftet med emulatorimplementationen var att underlätta utvecklingen av mjukvaran genom att ta bort beroendet av hårdvaran. Baserat på studier av olika metoder, tillgängliga verktyg och tidigare arbeten skapades en emulatormodell för IOM 200 och ett koncept för hur den ska implementeras. Arbetet har även skapat en fungerande prototyp som kan exekvera ett mindre kodsegment från IOM 200 och därigenom validerar emulatormodellen. Emulatormodellen utformades på den redan befintliga FreeRTOS-simulatorn som finns tillgänglig i Linux. Anledningen är att FreeRTOS används i IOM 200, den är gratis att använda och den möter emulatorns abstraktionskrav. Utöver FreeRTOS-simulatorn implementerades stubbar och wrapper-funktioner som tillhandahöll gränssnitt som gjorde IOM 200 applikationen exekverbar i emulatorn. / In this work an emulator for DeLaval’s embedded system IOM 200 has been developed in a Linux environment. The concept was to implement the emulator in DeLaval’s software test process for embedded systems. The purpose of creating an emulator was to ease the development of the embedded software by removing the dependency on embedded hardware. An emulator model and a concept for its implementation was created through the studies of various methods, available tools, and existing works in the emulator field. Based on the model the work created a working prototype that can execute a smaller code segment from the IOM 200 application. The emulator model was designed on the already existing FreeRTOS simulator that is available forLinux. The motive being that FreeRTOS is the operating system running on IOM 200, it is open source, free to use and it has the perfect level of abstraction for the emulator. Stubs and wrappers were implemented to the emulator in addition to the FreeRTOS simulator. These stubs and wrappers provided the interfaces needed for the IOM 200 application to be executable in the emulator.