[Bug 1838070] Re: Unable to add dyndbg to command line

[Tomáš Virtus]

This is not correct. The advice applies only to enabling debug messages
in modules, but how does one enable debug messages kernel image? For
example one could want to see debug messages from kernel/module.c which
is not in any module, and the kernel parameter would be:

  dyndbg="file kernel/module.c +p"

but grub turns that into

  "dyndbg=file kernel/module.c +p"

which kernel fails to parse.

There are other reports on the web:
http://savannah.gnu.org/bugs/?44580
https://access.redhat.com/solutions/1152603
https://lists.ozlabs.org/pipermail/petitboot/2016-September/000477.html

** Bug watch added: GNU Savannah Bug Tracker #44580
   http://savannah.gnu.org/bugs/?44580

** Changed in: grub2 (Ubuntu)
       Status: Invalid => Confirmed

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https://bugs.launchpad.net/bugs/1838070

Title:
  Unable to add dyndbg to command line

Status in grub2 package in Ubuntu:
  Confirmed

Bug description:
  I'm running Ubuntu 18.04.2 LTS
  Version 2.02-2ubuntu8.13 of grub is installed.

  When I update my grub.cfg to include dyndbg, such as:

  linux   /boot/vmlinuz-5.2.0+
  root=UUID=e31d3503-30d5-4021-89ea-0ac921ce153f ro  console=ttyS0
  ignore_loglevel dyndbg="module e1000"

  the quotes are not handled properly.

  The resulting kernel boot gets -

  cat /proc/cmdline | more
  BOOT_IMAGE=/boot/vmlinuz-5.2.0+ root=UUID=e31d3503-30d5-4021-89ea-0ac921ce153f ro console=ttyS0 ignore_loglevel "dyndbg=module e1000 +p"

  As you can see, the first quote in the dyndbg param moved, thus
  invalidating the command line, and resulting in dyndbg not taking
  effect.

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