On 2023-06-01 10:27, Paul Moore wrote:
On Wed, May 31, 2023 at 10:13 PM Luiz Capitulino luizcap@amazon.com wrote:
Hi Paul,
A number of stable kernels recently backported this upstream commit:
""" commit 4ce1f694eb5d8ca607fed8542d32a33b4f1217a5 Author: Paul Moore paul@paul-moore.com Date: Wed Apr 12 13:29:11 2023 -0400
selinux: ensure av_permissions.h is built when needed"""
We're seeing a build issue with this commit where the "crash" tool will fail to start, it complains that the vmlinux image and /proc/version don't match.
A minimum reproducer would be having "make" version before 4.3 and building the kernel with:
$ make bzImages $ make modules
...
This only happens with commit 4ce1f694eb5 applied and older "make", in my case I have "make" version 3.82.
If I revert 4ce1f694eb5 or use "make" version 4.3 I get identical strings (except for the "Linux version" part):
Thanks Luiz, this is a fun one :/
It was a fun to debug TBH :-)
Based on a quick search, it looks like the grouped target may be the cause, especially for older (pre-4.3) versions of make. Looking through the rest of the kernel I don't see any other grouped targets, and in fact the top level Makefile even mentions holding off on using grouped targets until make v4.3 is common/required.
Exactly.
I don't have an older userspace immediately available, would you mind trying the fix/patch below to see if it resolves the problem on your system? It's a cut-n-paste so the patch may not apply directly, but it basically just removes the '&' from the make rule, turning it into an old-fashioned non-grouped target.
I tried the attached patch on top of latest Linus tree (ac2263b588dffd), but unfortunately I got the same issue which is puzzling. Reverting 4ce1f694eb5d8ca607fed8542d32a33b4f1217a5 does solve the issue though.
I have no problem trying patches or helping debug, but if you want to give it a try on reproducing you could try with make-3.82 from:
https://ftp.gnu.org/gnu/make/make-3.82.tar.bz2
- Luiz