[kpatch] Kpatch-build related question

[Ajey Kulkarni]

Hi there,
I’m trying to build a kernel live patch for Linux kernel 4.4.27 version within a docker.
I did use the following link to install necessary dependencies.

https://github.com/dynup/kpatch

Since we are building inside docker against an older kernel, my understanding is
Kpatch-build will try to build older format of live patch using  create-kpatch-module.
I do see both original .o and patched .o in the relevant directories inside docker.

But create-kpatch-module is not being called and I'm getting an error
indicating "Makefile target missing".

Upon further inspection (with -d oputput and from the script itself)
+ /usr/local/libexec/kpatch/create-kpatch-module /home/xyz/.kpatch/tmp/patch/tmp_output.o /home/xyz/.kpatch/tmp/patch/output.o
+ local to_stdout=1
+ [[ 1 -ge 2 ]]
+ [[ 1 -eq 1 ]]
+ tee -a /home/racker/.kpatch/build.log
+ check_pipe_status create-kpatch-module
+ rc=0
+ [[ 0 = 139 ]]
+ cd /home/xyz/.kpatch/tmp/patch
+ logger
+ KPATCH_BUILD=/source/linux
+ KPATCH_NAME=kpatch-4-4-0-2-modules-0-3-2-3-x86_64
+ KBUILD_EXTRA_SYMBOLS=/usr/lib/modules/4.4.0+2/extra/kpatch/Module.symvers
+ KPATCH_LDFLAGS=
+ make
This is where it’s failing. The script comparison is with “139” which is SIGSEGV. I don’t see
any core files either in the working directory.

Questions are

  1.  Is building live patches for older version using docker a good idea?
  2.  Is building live patch on actual VM instead of docker recommended?
  3.  Is the Makefile target missing error, known bug? I would like to open a bug
If possible. Or am I missing something here?

Regards,
-Ajey
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