linux-kernel - Re: [PATCH] um: let 'make clean' properly clean underlying SUBARCH as well

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAK7LNAT_m+R3Keyys2NpmQWRmZzHNv9FM_ALv=vn_WMzTSWhyw@mail.gmail.com>
Date: Thu, 8 May 2025 17:14:15 +0900
From: Masahiro Yamada <masahiroy@...nel.org>
To: Geert Uytterhoeven <geert@...ux-m68k.org>
Cc: Johannes Berg <johannes@...solutions.net>, Shuah Khan <skhan@...uxfoundation.org>, 
	linux-kbuild@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Anton Ivanov <anton.ivanov@...bridgegreys.com>, Richard Weinberger <richard@....at>, 
	linux-um@...ts.infradead.org, David Gow <davidgow@...gle.com>
Subject: Re: [PATCH] um: let 'make clean' properly clean underlying SUBARCH as well

On Thu, May 8, 2025 at 4:38 PM Geert Uytterhoeven <geert@...ux-m68k.org> wrote:
>
> Hi Johannes,
>
> On Thu, 8 May 2025 at 07:29, Johannes Berg <johannes@...solutions.net> wrote:
> > On Wed, 2025-05-07 at 15:38 -0600, Shuah Khan wrote:
> > > My workflow:
> > >
> > > - Build kernel on x86_64 with CONFIG_AMD_MEM_ENCRYPT enabled
> > >
> > > - Check for arch/x86/realmode/rm/pasyms.h
> > >    ls arch/x86/realmode/rm/pasyms.h
> > >       arch/x86/realmode/rm/pasyms.h
> > >
> > > - make ARCH=um O=/linux/build
> > >
> > >    This patch cleans the source tree, but doesn't remove
> > >    arch/x86/realmode/rm/pasyms.h
> > >
> > > - ls arch/x86/realmode/rm/pasyms.h
> > >       arch/x86/realmode/rm/pasyms.h
> >
> > Is that even _expected_ to work? If you have x86 built first, I'd almost
> > expect you to have to do "make ARCH=x86 mrproper" before building
> > another ARCH. I don't see how ARCH=um would know how to do a full clean
> > up of ARCH=x86, unless this is somehow arch-independent?
> >
> > Or maybe that's not an issue with other architectures because UML is
> > special in that it uses parts of x86?
>
> Probably.
> I only use my linux-next source tree for fixing reported build issues on
> various architectures, and I never use make clean/mrproper.  Works fine.
>
> > Though I guess the patch here should make it do that, more or less, but
> > it can't, likely because you're also switching from in-tree build to O=
> > build?
>
> Yeah, mixing in-tree and out-of-tree builds causes issues.
> Never build in-tree in a source tree you use with O= (except for
> e.g. "make tags").
>

I argue this.

You can start out-of-tree builds after running 'make mrproper'
for the architecture you want to build the kernel for.

Hence, Kbuild suggests to do so when it determines
the source tree is not clean enough.

Unfortunately, "make mrproper ARCH=um" did not clean the tree
deeply enough.   Hence, this patch.


-- 
Best Regards
Masahiro Yamada