Comment 0 for bug 1806766

dann frazier (dannf) wrote :

[Impact]
kdump support isn't usable on HiSilicon D05 systems. This previously worked in bionic.

[Test Case]
sudo apt install linux-crashdump
echo 'GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT crashkernel=512M"' | \
  sudo tee /etc/default/grub.d/kdump-tools.cfg
sudo update-grub
sudo reboot
echo 1 | sudo tee /proc/sys/kernel/sysrq
echo c | sudo tee /proc/sysrq-trigger

[Fix]
2 upstream patch series are required to fix this:
 https://<email address hidden>/msg10328.html
Which provides an EFI facility consumed by:
 https://lkml.org/lkml/2018/9/21/1066
There were also some follow-on fixes to deal with ARM-specific problems associated with this usage:
 https://www.spinics.net/lists/arm-kernel/msg685751.html

[Regression Risk]
The EFI changes are in architecture independent code where they add a new table and an API for adding regions to that table. However, this API is only used by the gic-v3-its driver, which is ARM-specific. On other architectures, this will be an empty table. It's possible that there is a bug bug in the table creation code that could cause regressions on other architectures, which would likely be seen in the form of a boot time error message (Failed to install memreserve config table).