Debugging the BPF Virtual Machine Lorenzo Fontana October 28, 2020 ● Debugging is useful to understand how things work ● Sometimes, eBPF programs can’t even load ● I couldn’t find good resources on this this, so, here I am ● I break lots of eBPF programs ● The BPF Virtual machine is not easy to understand Why ? The BPF subsystem lives in the kernel AND The kernel can be debugged using gdb The

program. The Live Server installer uses a text-based console interface which runs on the default virtual console. The interface can be entirely driven by the enter, up and down arrow keys (with some occasional There are three options: • No automatic updates: this requires an administrator to log into the machine and manually install updates. • Install security updates automatically: this will install the unattended-upgrades Tomcat Java server: Installs Apache Tomcat and needed dependencies. • Virtual Machine host: Includes packages needed to run KVM virtual machines. • Manually select packages: Executes aptitude allowing you

install/netboot-arm64 arm64 netboot install 3 install/netboot-ppc64el ppc64el netboot install 3 install/ppc64el Virtual CDROM and Petitboot on ppc64el 1 Level Path Navlink 3 install/s390x-zvm s390x install via z/VM Security tips 3 wireguard-vpn-troubleshooting Troubleshooting 2 Virtualisation and containers 3 Virtual machines 4 virtualization-qemu QEMU 4 virtualization-multipass Multipass 4 virtualization-uvt UVtool and containers 3 Virtual machines 4 vm-tools-in-the-ubuntu-space VM tools overview 4 using-qemu-for-microvms QEMU for microVMs 4 upgrading-the-machine-type-of-your-vm Upgrading machine type 3 Containers

3 Apache Virtual Host documentation 109 3.1 Apache Virtual Host documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 iii iv CONTENTS 3.2 Name-based Virtual Host Support . . . . . 111 3.3 Apache IP-based Virtual Host Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 3.4 Dynamically Configured Mass Virtual Hosting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 3.6 An In-Depth Discussion of Virtual Host Matching . . . . . . . . . . . . . . . . . . . . . . . . . . 129 3.7 File Descriptor Limits

and Windows XP. This support does not extend to Windows 95, 98 or ME, which continue to use the machine's local codepage for filesystem access. Regular Expression Library Updated Apache 2.0 includes configuration. Apache has the capability to serve many different websites simultaneously. This is called Virtual Hosting. Directives can also be scoped by placing them inside sections, so that they of the specific URL. Virtual Hosts The container encloses directives that apply to specific hosts. This is useful when serving multiple hosts from the same machine with a different configuration

and Windows XP. This support does not extend to Windows 95, 98 or ME, which continue to use the machine's local codepage for filesystem access. Regular Expression Library Updated Apache 2.0 includes configuration. Apache has the capability to serve many different websites simultaneously. This is called Virtual Hosting. Directives can also be scoped by placing them inside sections, so that they of the specific URL. Virtual Hosts The container encloses directives that apply to specific hosts. This is useful when serving multiple hosts from the same machine with a different configuration

and Windows XP. This support does not extend to Windows 95, 98 or ME, which continue to use the machine's local codepage for filesystem access. Regular Expression Library Updated Apache 2.0 includes configuration. Apache has the capability to serve many different websites simultaneously. This is called Virtual Hosting. Directives can also be scoped by placing them inside sections, so that they of the specific URL. Virtual Hosts The container encloses directives that apply to specific hosts. This is useful when serving multiple hosts from the same machine with a different configuration

and Windows XP. This support does not extend to Windows 95, 98 or ME, which continue to use the machine's local codepage for filesystem access. Regular Expression Library Updated Apache 2.0 includes configuration. Apache has the capability to serve many different websites simultaneously. This is called Virtual Hosting. Directives can also be scoped by placing them inside sections, so that they of the specific URL. Virtual Hosts The container encloses directives that apply to specific hosts. This is useful when serving multiple hosts from the same machine with a different configuration

3 Apache Virtual Host documentation 93 3.1 Apache Virtual Host documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 iii iv CONTENTS 3.2 Name-based Virtual Host Support . . . . . . 95 3.3 Apache IP-based Virtual Host Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 3.4 Dynamically configured mass virtual hosting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 3.6 An In-Depth Discussion of Virtual Host Matching . . . . . . . . . . . . . . . . . . . . . . . . . . 113 3.7 File Descriptor Limits

and Windows XP. This support does not extend to Windows 95, 98 or ME, which continue to use the machine's local codepage for filesystem access. Regular Expression Library Updated Apache 2.0 includes configuration. Apache has the capability to serve many different websites simultaneously. This is called Virtual Hosting. Directives can also be scoped by placing them inside sections, so that they of the specific URL. Virtual Hosts The container encloses directives that apply to specific hosts. This is useful when serving multiple hosts from the same machine with a different configuration