| 2020-09-24 10:40:07 |
Andrea Righi |
description |
Hi,
When running Groovy daily images on i3.metal instances a broken /dev/console is created. The char device appears to be writable but writing to it causes an Input/output error. This is breaking cloud-init, as it tries to log to /dev/console, and is likely to break other programs.
On Focal:
root@ip-172-31-24-163:~# ls -l /dev/console
crw------- 1 root root 5, 1 Sep 21 16:07 /dev/console
root@ip-172-31-24-163:~# echo x > /dev/console
root@ip-172-31-24-163:~#
On Groovy:
root@ip-172-31-20-184:~# ls -l /dev/console
crw--w---- 1 root tty 5, 1 Sep 21 16:03 /dev/console
root@ip-172-31-20-184:~# echo x > /dev/console
bash: echo: write error: Input/output error
The Groovy kernel log has a
[ 3.561696] fbcon: Taking over console
line in it, which is not present in the Focal kernel log (5.4.0-1024-aws). Perhaps fbcon should be prevented from taking over console? |
[Impact]
Starting with kernel 5.8 the default nr_uarts has been changed from 4 to 2 for amd64, but this seems to affect i3.metal instances in AWS, because ttyS0 is now remapped to ttyS4 and this is breaking tools like cloud-init (and probably something else).
[Test case]
# echo > /dev/console
bash: echo: write error: Input/output error
[Fix]
Setting nr_uarts=4 by default (via CONFIG_SERIAL_8250_RUNTIME_UARTS) restores the previous behavior and writing to /dev/console works without returning any error.
[Regression potential]
Minimal. Restores the old behavior used in 5.4 (that shouldn't have changed in the first place).
[Original bug report]
Hi,
When running Groovy daily images on i3.metal instances a broken /dev/console is created. The char device appears to be writable but writing to it causes an Input/output error. This is breaking cloud-init, as it tries to log to /dev/console, and is likely to break other programs.
On Focal:
root@ip-172-31-24-163:~# ls -l /dev/console
crw------- 1 root root 5, 1 Sep 21 16:07 /dev/console
root@ip-172-31-24-163:~# echo x > /dev/console
root@ip-172-31-24-163:~#
On Groovy:
root@ip-172-31-20-184:~# ls -l /dev/console
crw--w---- 1 root tty 5, 1 Sep 21 16:03 /dev/console
root@ip-172-31-20-184:~# echo x > /dev/console
bash: echo: write error: Input/output error
The Groovy kernel log has a
[ 3.561696] fbcon: Taking over console
line in it, which is not present in the Focal kernel log (5.4.0-1024-aws). Perhaps fbcon should be prevented from taking over console? |
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