A Linux kernel mentoring journey by Javier Garcia

 arghhhhh ... after so much time building all the sources the vmlinux is not created.   I did repeat the process after a make clean and an extra hour ... but again no vmlinux     The kernel build process has several steps like creating .o from .c and .h files but then objtool will do an static analysis of the generated object.   The problem comes at the end when the biggest vmlinux object must be analyzed with objtool and if options like  CONFIG_DEBUG_INFO the number DWARF data increases and eveything blows.   How much memory you'll need ... in my case with a 16GB laptop needed to add swap to allow generate finally the vmlinux  .   In the image you can see objtool with 79.93% of the memory , so aprox 12GB of ram     

 One of the initial tasks when you start working in the Linux Kernel as a newbie is fixing errors. To fix errors the way to go is pick an error from the  syzkaller   I'll try to add here some tricks to help you work with less headaches based in my own headaches :   The basic step to reproduce the error is run the  repro  C program that it's provided in the page of the selected error. The problem I had is after some successful tries to reproduce the error suddenly it didn't work anymore. I was able to run the program but it ends and with no error. What I've found is that the sandbox folder for the  repro  already exists and that caused the problem. The solution was as easy as to delete the  syz-tmp folder in the image you're using to run your kernel and reproduce the error. These two command in the host I use to run inside the qemu : scp -i ~/LF/syz/syzkaller/trixie.id_rsa -P 10021 -o UserKnownHostsFile=/dev/null -o ...

  Long time since I compiled my first kernel, I think it was a box with an Intel 386sx . Always with an eye on that area then this summer of 2025 in an entry an entry in LinkedIn I saw a comment about the Linux Foundation mentoring program so I joined to the kernel mentoring program. Now I’ve been accepted and I’m starting the journey… let’s see what I can learn and most important what I can contribute to this wonderful software that I’ve been using for decades now.