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Showing posts from September 16, 2020

DailyLog: 20200916

 Workflow: Allocating a page from user space                       Learning     Enable Tracing: https://www.kernel.org/doc/html/v4.18/trace/events.html  Not able to enable the same Tracing is enabled for my kernel - I was able to turn on for page allocation Check vim /sys/kernel/debug/tracing/trace https://events.static.linuxfound.org/sites/events/files/slides/praesentation_0.pdf  Another PPT:  https://events19.linuxfoundation.org/wp-content/uploads/2017/12/oss-eu-2018-fun-with-dynamic-trace-events_steven-rostedt.pdf (Even better!)        

DailyLog: 20200913

 DailyLog: 20200913 Part I: Linux Kernel Module Compilation + Loading Question: Having trouble loading up your module Answer:   #1 Finally found something on it. It appears to be a "feature" where unsigned code can't be loaded into the kernel when UEFI secure boot is enabled (which it is). To get the module loading, disable kernel lockdown via sys-rq: # echo 1 > /proc/sys/kernel/sysrq # echo x > /proc/sysrq-trigger Then modprobe should work: modprobe wireguard For more information, see: https://mjg59.dreamwidth.org/50577.html https://bugzilla.redhat.com/show_bug.cgi?id=1599197   Issue 1. Cannot turn the sysrq off (Hmmm...)   #2 From https://stackoverflow.com/questions/29036987/insmod-error-in-kernel-module-programming Steps to securely sign your kernel modules: Create a X509 certificate that can be imported in firmware Enrolling the public key just created Sign the module you want to install Install the module    To sign kernel modules, we can