On Wed, May 31, 2023 at 10:13 PM Luiz Capitulino <luizcap@xxxxxxxxxx> wrote:
>
> Hi Paul,
>
> A number of stable kernels recently backported this upstream commit:
>
> """
> commit 4ce1f694eb5d8ca607fed8542d32a33b4f1217a5
> Author: Paul Moore <paul@xxxxxxxxxxxxxx>
> 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 :/
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.
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.
diff --git a/security/selinux/Makefile b/security/selinux/Makefile
index 0aecf9334ec3..df35d4ec46f0 100644
--- a/security/selinux/Makefile
+++ b/security/selinux/Makefile
@@ -26,5 +26,5 @@ quiet_cmd_flask = GEN $(obj)/flask.h $(obj)/av_permissions
.h
cmd_flask = $< $(obj)/flask.h $(obj)/av_permissions.h
targets += flask.h av_permissions.h
-$(obj)/flask.h $(obj)/av_permissions.h &: scripts/selinux/genheaders/genheaders
FORCE
+$(obj)/flask.h $(obj)/av_permissions.h: scripts/selinux/genheaders/genheaders F
ORCE
$(call if_changed,flask)
--
paul-moore.com
