linux: CONFIG_SERIAL_8250_MID=y

[Vladimir Ratnikov]

[Impact]

CONFIG_SERIAL_8250_MID=y is required to properly use the serial console on some platforms that are using the "mid" serial driver (such as some Intel SoC platforms).

The generic kernel should build this driver statically to make sure we properly support these platforms.

[Test case]

Boot the Ubuntu generic kernel on a system that is using the "mid" serial driver (e.g, no PCI serial).

[Fix]

Enable CONFIG_SERIAL_8250_MID=y.

[Regression potential]

Kernel footprint is increased a bit with this change (around +9K), so we may see little performance regressions at boot time in really small platforms (additional memory usage is probably negligible), but it is worth it, otherwise we won't be able to properly support these platforms.

NOTE: we may want to disable this option in the could kernels and derivatives and keep it only for the generic.

[Original bug report]

Starting from 5.19 HWE kernel, this option became as dedicated module instead of being compiled into the kernel.
5.19 hwe-next also has CONFIG_SERIAL_8250_MID=m
On 5.15 it was OK

~$ uname -r
5.19.0-32-generic
$ cat /boot/config-5.19.0-32-generic | grep 8250_MID
CONFIG_SERIAL_8250_MID=m

Please make it CONFIG_SERIAL_8250_MID=y for all the future kernels.

Previous ticket: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1967338
Some discussion: https://lists.ubuntu.com/archives/kernel-team/2022-March/128690.html

Thanks!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 2009283

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Dimitri John Ledkov (xnox)]

I understand that having it in the root filesystem is too late.

However, I would have thought it would be good enough to have it early in the initrd, or do you also require output prior to initrd starting? having it built-in trades wasting RAM for all billions of Ubuntu instances, and the module in question is large.

[Renato Botelho (garga)]

Hello Dimitri!

Unfortunately, if it's not built-in we have no console and system cannot be installed. Same change was made on debian years ago to solve the same problem, as you can see at:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=864368

https://salsa.debian.org/kernel-team/linux/-/commit/7618511643be57b5587f66729e1c0121eb4617f6

[Renato Botelho (garga)]

I also found this:

To use a serial port as console you need to compile the support into your kernel - by default it is not compiled in. For PC style serial ports it’s the config option next to menu option:

Character devices ‣ Serial drivers ‣ 8250/16550 and compatible serial support ‣ Console on 8250/16550 and compatible serial port

You must compile serial support into the kernel and not as a module.

at https://www.kernel.org/doc/html/latest/admin-guide/serial-console.html

[Andrea Righi (arighi)]

I've applied this change to lunar. Next lunar 6.2 kernel will have CONFIG_SERIAL_8250_MID=y.

[Renato Botelho (garga)]

Hello! Thanks for addressing this issue.

Will this fix reach jammy HWE kernel at some point?

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 6.2.0-18.18

---------------
linux (6.2.0-18.18) lunar; urgency=medium

  * lunar/linux: 6.2.0-18.18 -proposed tracker (LP: #2011750)

  * lunar/linux 6.2 fails to boot on arm64 (LP: #2011748)
    - SAUCE: Revert "efi: random: fix NULL-deref when refreshing seed"
    - SAUCE: Revert "efi: random: refresh non-volatile random seed when RNG is
      initialized"

 -- Andrea Righi <email address hidden> Wed, 15 Mar 2023 23:54:18 +0100

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux/5.19.0-40.41 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-kinetic' to 'verification-done-kinetic'. If the problem still exists, change the tag 'verification-needed-kinetic' to 'verification-failed-kinetic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Renato Botelho (garga)]

We tested and confirmed it's fine on proposed kinetic kernel

Thanks!

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 5.19.0-40.41

---------------
linux (5.19.0-40.41) kinetic; urgency=medium

  * kinetic/linux: 5.19.0-40.41 -proposed tracker (LP: #2012668)

  * CVE-2023-0468
    - io_uring: fix tw losing poll events
    - io_uring: make poll refs more robust

  * Regression in ext4 during online resize (LP: #2003816)
    - ext4: fix bad checksum after online resize
    - ext4: fix corruption when online resizing a 1K bigalloc fs
    - ext4: fix corrupt backup group descriptors after online resize

linux (5.19.0-39.40) kinetic; urgency=medium

  * kinetic/linux: 5.19.0-39.40 -proposed tracker (LP: #2011876)

  * CVE-2023-26545
    - net: mpls: fix stale pointer if allocation fails during device rename

  * CVE-2023-1032
    - net: avoid double iput when sock_alloc_file fails

  * CVE-2022-41218 // CVE-2022-41218 is assigned to those bugs above.
    - media: dvb-core: Fix UAF due to refcount races at releasing

  * CVE-2023-1281
    - net/sched: tcindex: update imperfect hash filters respecting rcu

  * linux: CONFIG_SERIAL_8250_MID=y (LP: #2009283)
    - [Config] enable CONFIG_SERIAL_8250_MID=y

  * apply the latest TDX attestation driver from Intel (LP: #2009437)
    - Revert "UBUNTU: SAUCE: selftests: tdx: Test GetReport TDX attestation
      feature"
    - Revert "UBUNTU: SAUCE: x86/tdx: Add TDX Guest attestation interface driver"
    - x86/tdx: Add a wrapper to get TDREPORT0 from the TDX Module
    - virt: Add TDX guest driver
    - selftests/tdx: Test TDX attestation GetReport support
    - [Config] enable TDX attestation driver as module by default

  * cpufreq: intel_pstate: Update Balance performance EPP for Sapphire Rapids
    (LP: #2008519)
    - cpufreq: intel_pstate: Adjust balance_performance EPP for Sapphire Rapids

  * Fail to output sound to external monitor which connects via docking station
    (LP: #2009024)
    - [Config] Enable CONFIG_SND_HDA_INTEL_HDMI_SILENT_STREAM

  * Fix mediatek wifi driver crash when loading wrong SAR table (LP: #2009118)
    - wifi: mt76: mt7921: fix error code of return in mt7921_acpi_read

  * CVE-2022-47929
    - net: sched: disallow noqueue for qdisc classes

  * Intel graphic driver is not probing[8086:468b] (LP: #1990242)
    - drm/i915: Add new ADL-S pci id

  * Some QHD panels fail to refresh when PSR2 enabled (LP: #2009014)
    - drm/i915/psr: Use full update In case of area calculation fails
    - drm/i915: Ensure damage clip area is within pipe area
    - SAUCE: drm/i915/psr: Use calculated io and fast wake lines

  * overlayfs mounts as R/O over idmapped mount (LP: #2009065)
    - SAUCE: overlayfs: handle idmapped mounts in ovl_do_(set|remove)xattr

  * Kinetic update: upstream stable patchset 2023-02-28 (LP: #2008832)
    - usb: musb: remove extra check in musb_gadget_vbus_draw
    - arm64: dts: qcom: ipq6018-cp01-c1: use BLSPI1 pins
    - arm64: dts: qcom: sm8250-sony-xperia-edo: fix touchscreen bias-disable
    - arm64: dts: qcom: msm8996: Add MSM8996 Pro support
    - arm64: dts: qcom: msm8996: fix supported-hw in cpufreq OPP tables
    - arm64: dts: qcom: msm8996: fix GPU OPP table
    - ARM: dts: qcom: apq8064: fix coresight compatible
    - arm64: dts:...

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-ibm/5.19.0-1021.23 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-kinetic' to 'verification-done-kinetic'. If the problem still exists, change the tag 'verification-needed-kinetic' to 'verification-failed-kinetic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Renato Botelho (garga)]

I'm trying to validate IBM kernel to make sure fix is in place and avoid it to being reverted but kinetic proposed repo still doesn't show version 5.19.0-1021, it has 5.19.0-1020. How can I verify it in 5 days if it's not there?

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-aws/5.19.0-1025.26 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-kinetic' to 'verification-done-kinetic'. If the problem still exists, change the tag 'verification-needed-kinetic' to 'verification-failed-kinetic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-azure/5.19.0-1026.29 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-kinetic' to 'verification-done-kinetic'. If the problem still exists, change the tag 'verification-needed-kinetic' to 'verification-failed-kinetic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-nvidia-5.19/5.19.0-1010.10 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy' to 'verification-done-jammy'. If the problem still exists, change the tag 'verification-needed-jammy' to 'verification-failed-jammy'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Vladimir Ratnikov (vratnikov)]

linux-image-unsigned-5.19.0-1010-nvidia/jammy-proposed,now 5.19.0-1010.10 amd64 [installed]
linux-modules-5.19.0-1010-nvidia/jammy-proposed,now 5.19.0-1010.10 amd64 [installed,automatic]

CONFIG_SERIAL_8250_MID=y

[Renato Botelho (garga)]

I'm not sure which tags I'm supposed to add here, but I verified ibm, aws and azure kernels from kinetic-proposed and they don't contain the fix.

root@kinetic:~# grep 8250_MID /boot/config-5.19.0-1025-aws
CONFIG_SERIAL_8250_MID=m
root@kinetic:~# grep 8250_MID /boot/config-5.19.0-1026-azure
CONFIG_SERIAL_8250_MID=m
root@kinetic:~# grep 8250_MID /boot/config-5.19.0-1021-ibm
CONFIG_SERIAL_8250_MID=m