why my hash functions doesnt work or freez in the /sys/kernel/tracing/per

Im having issue with my script that calulates intergity on this version of ubunutu :

cyber@ubuntu:/$ hostnamectl
   Static hostname: ubuntu
         Icon name: computer-vm
           Chassis: vm
        Machine ID: 48d13c046d74421781e6c6f771f6ac31
           Boot ID: 847b838897ac47eb932f6427361232d1
    Virtualization: vmware
  Operating System: Ubuntu 20.04.4 LTS
            Kernel: Linux 5.13.0-51-generic
      Architecture: x86-64

Im wondering if /sys/kernel/tracing/per_cpu/cpu45 is not by any chance an alive file ? because calculating the hash of the files inside takes ifinite time.

CodePudding user response：

If you want to check filesystem integrity, skip the whole /sys folder - it is an interface to the kernel.

Also it would be better if you also skip /proc (also kernel interface) and /dev (special or device files) folders. F.e - you can read from /dev/zero or /dev/urandom forever.

Also your script can freeze on reading pipes - it there is enough permissions it can read from a pipe forever.

If I was building such a script, I'll start from the mounts, checked their filesystems and scanned only needed ones. For example if a mount is tmpfs - it's contents is located in RAM and will be wiped after reboot.

And you totally should check it out - https://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard