[Xenial] dahdi-dkms fails to build after kernel version 4.4.218
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
dahdi-linux (Ubuntu) |
Invalid
|
Medium
|
Unassigned | ||
Xenial |
Fix Released
|
Medium
|
Stefan Bader |
Bug Description
In upstream stable 4.4.218, the following patch brings back kref_read() which was re-implemented in dahdi-linux code for kernel versions before 4.11:
commit 408f17931f54517
Author: Peter Zijlstra <email address hidden>
Date: Mon Nov 14 17:29:48 2016 +0100
locking/atomic, kref: Add kref_read()
This needs adjustment now in Xenial for kernels including 4.4.218 and later.
[SRU Justification]
== Impact ==
Dahdi-dkms fails to build for kernels which include upstream stable version 4.4.218 or later.
== Fix ==
Disable the internal re-implementation of kref_read() for kernels including upstream stable 4.4.218.
== Testcase ==
Running dkms build for various kernel versions (tested with Ubuntu-4.4.0-178 and Ubuntu-4.4.0-179). With -178 building currently succeeds, with -179 it fails.
== Risk of Regression ==
Low, internal implementation which was backported from kernel 4.11 gets replaced by the kernel function.
Fix by disabling the internal definition of kref_read() for kernel versions >= 4.4.218.