Unable to build lttng-module with Artful kernel

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 1756240

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.

This issue can be reproduced with Xenial HWE kernel as well (4.13)

03/20 05:22:06 DEBUG| utils:0153| [stdout] Building initial module for 4.15.0-13-lowlatency
03/20 05:22:14 DEBUG| utils:0153| [stdout] Error! Bad return status for module build on kernel: 4.15.0-13-lowlatency (x86_64)
03/20 05:22:14 DEBUG| utils:0153| [stdout] Consult /var/lib/dkms/lttng-modules/2.8.0/build/make.log for more information.

Sorry in comment #3 it's the Xenial Edge kernel (4.15), this is the Xenial HWE one:

03/16 01:12:07 DEBUG| utils:0153| [stdout] Error! Bad return status for module build on kernel: 4.13.0-38-lowlatency (x86_64)
03/16 01:12:07 DEBUG| utils:0153| [stdout] Consult /var/lib/dkms/lttng-modules/2.8.0/build/make.log for more information.
03/16 01:12:07 DEBUG| utils:0153| [stdout] Setting up lttng-tools (2.7.1-2ubuntu1) ...

This build failure occurs because of the following artful commit:

commit 356852284931cda6749c41f77acefcb13bd534fe
Author: Wanpeng Li <email address hidden>
Date: Thu Jan 4 01:57:52 2018 -0500

    KVM: Fix stack-out-of-bounds read in write_mmio

    CVE-2017-17741

This redefines the kvm_mmio trace event as follows:

 TRACE_EVENT(kvm_mmio,
- TP_PROTO(int type, int len, u64 gpa, u64 val),
+ TP_PROTO(int type, int len, u64 gpa, void *val),
        TP_ARGS(type, len, gpa, val),

..which is different from the lttng prototype in instrumentation/events/lttng-module/kvm.h:

#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,15,0) \
        || LTTNG_KERNEL_RANGE(4,14,14, 4,15,0) \
        || LTTNG_KERNEL_RANGE(4,9,77, 4,10,0) \
        || LTTNG_KERNEL_RANGE(4,4,112, 4,5,0) \
        || LTTNG_KERNEL_RANGE(3,16,52, 3,17,0) \
        || LTTNG_KERNEL_RANGE(3,2,97, 3,3,0) \
        || LTTNG_DEBIAN_KERNEL_RANGE(4,9,65,0,3,0, 4,10,0,0,0,0))

LTTNG_TRACEPOINT_EVENT(kvm_mmio,
        TP_PROTO(int type, int len, u64 gpa, void *val),
        TP_ARGS(type, len, gpa, val),

        TP_FIELDS(
                ctf_integer(u32, type, type)
                ctf_integer(u32, len, len)
                ctf_integer(u64, gpa, gpa)
                ctf_sequence_hex(unsigned char, val, val, u32, len)
        )
)

#else

LTTNG_TRACEPOINT_EVENT(kvm_mmio,
        TP_PROTO(int type, int len, u64 gpa, u64 val),
        TP_ARGS(type, len, gpa, val),

        TP_FIELDS(
                ctf_integer(u32, type, type)
                ctf_integer(u32, len, len)
                ctf_integer(u64, gpa, gpa)
                ctf_integer(u64, val, val)
        )
)

Not sure how we #ifdef around this as the kernel version is 4.13 yet it now has a 4.15 API

Can we fix this by modifying the code in lttng-modules-dkms ? Something like "proposed-patch-1.txt"

4.13.0-38 introduced a new definition of kvm_mmio() that is backported from 4.15. There's already a list of excepted kernel versions for which the new (4.15) definition should be used. I added ubuntu 4.13.0-38-and-later kernels to that list.

Tested by first successfully building lttng-modules-dkms on 4.13.0-37, then reproducing the problem described here on 4.13.0-38, then applying the code-change and confirming that I can successfully build on both 4.13.0-37 and 4.13.0-38 after that.

Updated debdiff to fix a problem with macro arguments. Same testing as before.

Adding equivalent fix for xenial-hwe

@Khaled these debdiffs look good enough for me to sponsor. I made one superficial change by removing the "## " prefix from the patch tags lines. However, there were two important changes required for the Xenial debdiff. The version wasn't correct (I changed it to 2.8.0-1ubuntu1~16.04.5 instead of 2.8.0-1ubuntu1~16.04.4ubuntu1) and the changelog wasn't finalized (I changed "UNRELEASED" to "xenial"). Thanks for preparing the debdiffs and please remember these two things next time!

@sru-team I asked Khaled, over IRC, if these changes were need in Bionic. He says, "I don't think so - bionic would take the 4.15 definition by default. So the problem would only affect ubuntu kernels version 4.13.0-38 up to (but not including) 4.15.x-y".

I've sponsored these (adjusted) debdiffs to artful and xenial. Thanks again!

@Khaled after giving it a little more thought, I think these changes might be needed in bionic in the situation that an artful user is upgrading to bionic or when a xenial hwe user is upgrading to bionic. I think that if the lttng-modules-dkms binary package is upgraded to the bionic package bionic while there are still kernels installed from the old release, the user will see this bug. Could you test these situations or just get out a bigger hammer and prepare a bionic debdiff that I can sponsor?

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 1756240

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.

The attachment "proposed-fix" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

Fix for bionic - lots of thanks to @tyhicks for the explanation and help

lgtm! sponsored to bionic

This bug was fixed in the package lttng-modules - 2.10.5-1ubuntu1

---------------
lttng-modules (2.10.5-1ubuntu1) bionic; urgency=medium

  * Fix builds for 4.13.0-38 kernel (LP: #1756240)
    - Update definition of kvm_mmio() to match the new kernel

 -- Khalid Elmously <email address hidden> Fri, 23 Mar 2018 10:20:08 -0400

Hello Po-Hsu, or anyone else affected,

Accepted lttng-modules into artful-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/lttng-modules/2.9.0-1ubuntu3.2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-artful to verification-done-artful. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-artful. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Fix has been merged into mainline lttng as well:

git://git.lttng.org/lttng-modules.git be02509026192106196fe6dfd9df0db739804045

The fix works as expected, thanks.

Hello Po-Hsu, or anyone else affected,

Accepted lttng-modules into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/lttng-modules/2.8.0-1ubuntu1~16.04.5 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Tested on Xenial + 4.13 kernel, works as expected.
Thanks

Hello SRU team,

Verification appears to be complete for this fix and the holding period has ended. Could you please promote this to -updates?
Thanks

This bug was fixed in the package lttng-modules - 2.9.0-1ubuntu3.2

---------------
lttng-modules (2.9.0-1ubuntu3.2) artful; urgency=medium

  * Fix builds for 4.13.0-38 kernel (LP: #1756240)
    - Update definition of kvm_mmio() to match the new kernel

 -- Khalid Elmously <email address hidden> Wed, 21 Mar 2018 19:12:27 -0400

The verification of the Stable Release Update for lttng-modules has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

This bug was fixed in the package lttng-modules - 2.8.0-1ubuntu1~16.04.5

---------------
lttng-modules (2.8.0-1ubuntu1~16.04.5) xenial; urgency=medium

  * Fix builds for 4.13.0-38 kernel (LP: #1756240)
    - Update definition of kvm_mmio() to match the new kernel

 -- Khalid Elmously <email address hidden> Thu, 22 Mar 2018 12:08:10 -0400