From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by passt.top (Postfix) with ESMTP id 351495A026D for ; Wed, 23 Aug 2023 16:31:52 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1692801110; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=FVbjTIK0GFVtLSQeOVohvFLgArP0OCIEheklTufAhzg=; b=Xp4T2d9lPqpwM0U8MeEZTBi1zc91YqRpSRNPKJ9W6upCcVnuLCqqylaR9EFhAwKJsB3DWv ZPlLoJlZoGgGxXaYqOdDSr+k5BlYju7jS8ZJDv35faBQbII3zqBZx/6WWctsNB8xYKeH2U BM3Eaoa9F3edZpuvf1R2nMDQjbGdGcM= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-443-lSL4QRZaNKSmx_fpBnEkow-1; Wed, 23 Aug 2023 10:31:47 -0400 X-MC-Unique: lSL4QRZaNKSmx_fpBnEkow-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id F316A8D40A4; Wed, 23 Aug 2023 14:31:46 +0000 (UTC) Received: from localhost (unknown [10.42.28.187]) by smtp.corp.redhat.com (Postfix) with ESMTP id BE51E4A9004; Wed, 23 Aug 2023 14:31:46 +0000 (UTC) Date: Wed, 23 Aug 2023 15:31:46 +0100 From: "Richard W.M. Jones" To: Stefano Brivio Subject: Re: [PATCH] fedora: Replace pasta hard links by copies, mangle Build-IDs Message-ID: <20230823143146.GQ7636@redhat.com> References: <20230823134844.2188790-1-sbrivio@redhat.com> <20230823135327.GP7636@redhat.com> <20230823155939.7f603ffa@elisabeth> MIME-Version: 1.0 In-Reply-To: <20230823155939.7f603ffa@elisabeth> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Message-ID-Hash: Y73RKWS7723GSSCKFG34KP4RQK3SIUTB X-Message-ID-Hash: Y73RKWS7723GSSCKFG34KP4RQK3SIUTB X-MailFrom: rjones@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: devel@lists.fedoraproject.org, passt-dev@passt.top X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Wed, Aug 23, 2023 at 03:59:39PM +0200, Stefano Brivio wrote: > On Wed, 23 Aug 2023 14:53:27 +0100 > "Richard W.M. Jones" wrote: > > > On Wed, Aug 23, 2023 at 03:48:44PM +0200, Stefano Brivio wrote: > > > The hard link trick didn't actually fix the issue with SELinux file > > > contexts properly: as opposed to symbolic links, SELinux now > > > correctly associates types to the labels that are set -- except that > > > those labels are now shared, so we can end up (depending on how > > > rpm(8) extracts the archives) with /usr/bin/passt having a > > > pasta_exec_t context. > > > > > > This got rather confusing as running restorecon(8) seemed to fix up > > > labels -- but that's simply toggling between passt_exec_t and > > > pasta_exec_t for both links, because each invocation will just "fix" > > > the file with the mismatching context. > > > > > > Replace the hard links with copies. AppArmor's attachment, instead, > > > works with hard links, and if there's no LSM, we can keep symbolic > > > links, so keep symbolic links in the Makefile. > > > > > > With copies, rpmbuild(8) will warn about duplicate Build-IDs in the > > > same package. Mangle them in pasta binaries by summing one to the > > > last byte, modulo one byte, using xxd (provided by vim-common) and > > > disable the automatic rehashing by find-debuginfo(1) -- we already > > > have per-release Build-IDs thanks to $VERSION passed on 'make'. > > > > Right, this ^ was going to be my comment. RPM doesn't like having two > > identical copies of a file. > > In which other way, though? cpio(1) is fine with it, and I tried to > install the package on both ext4 and xfs -- the only warning I got was > the (semi-reasonable) one from rpmbuild about duplicate Build-IDs. I'm fairly sure I've seen an error when you have two identical files; it might only happen in Koji. Anyway, hacking the binary is surely wrong, but let's hear the opinions of the Fedora / SELinux developers. Rich. > > Hacking the binary to "fix" the problem doesn't sound like a solution. > > > > I'm CC-ing Fedora-devel-list to find out we can properly fix this issue. > > > > Rich. > > > > > Signed-off-by: Stefano Brivio > > > --- > > > contrib/fedora/passt.spec | 27 ++++++++++++++++++++++----- > > > 1 file changed, 22 insertions(+), 5 deletions(-) > > > > > > diff --git a/contrib/fedora/passt.spec b/contrib/fedora/passt.spec > > > index d0c6895..51bf5a8 100644 > > > --- a/contrib/fedora/passt.spec > > > +++ b/contrib/fedora/passt.spec > > > @@ -9,6 +9,10 @@ > > > > > > %global git_hash {{{ git_head }}} > > > %global selinuxtype targeted > > > +# Different Build-IDs for passt and pasta: don't let find-debuginfo touch them > > > +%undefine _unique_build_ids > > > +%global _no_recompute_build_ids 1 > > > + > > > > > > Name: passt > > > Version: {{{ git_version }}} > > > @@ -19,7 +23,7 @@ Group: System Environment/Daemons > > > URL: https://passt.top/ > > > Source: https://passt.top/passt/snapshot/passt-%{git_hash}.tar.xz > > > > > > -BuildRequires: gcc, make, checkpolicy, selinux-policy-devel > > > +BuildRequires: gcc, make, checkpolicy, selinux-policy-devel, binutils, vim-common > > > Requires: (%{name}-selinux = %{version}-%{release} if selinux-policy-%{selinuxtype}) > > > > > > %description > > > @@ -56,15 +60,28 @@ This package adds SELinux enforcement to passt(1) and pasta(1). > > > %install > > > > > > %make_install DESTDIR=%{buildroot} prefix=%{_prefix} bindir=%{_bindir} mandir=%{_mandir} docdir=%{_docdir}/%{name} > > > -# The Makefile creates symbolic links for pasta, but we need hard links for > > > +# The Makefile creates symbolic links for pasta, but we need actual copies for > > > # SELinux file contexts to work as intended. Same with pasta.avx2 if present. > > > -ln -f %{buildroot}%{_bindir}/passt %{buildroot}%{_bindir}/pasta > > > +# > > > +# To avoid duplicate Build-IDs in the same package, we increase the last byte of > > > +# the value for pasta binaries by one (modulo one byte). Note that we already > > > +# have differentiated Build-IDs per release, courtesy of $VERSION, so we don't > > > +# need find-debuginfo(1) to recalculate them. > > > +rm %{buildroot}%{_bindir}/pasta > > > +objcopy --dump-section .note.gnu.build-id=%{buildroot}/build_id %{buildroot}%{_bindir}/passt > > > +printf '\x'$(printf %02x $(( ( 0x$(xxd -ps -s 35 %{buildroot}/build_id) + 1 ) % 0xff )) ) | dd of=%{buildroot}/build_id seek=35 bs=1 count=1 conv=notrunc > > > +objcopy --update-section .note.gnu.build-id=%{buildroot}/build_id %{buildroot}%{_bindir}/passt %{buildroot}%{_bindir}/pasta > > > +rm %{buildroot}/build_id > > > + > > > %ifarch x86_64 > > > -ln -f %{buildroot}%{_bindir}/passt.avx2 %{buildroot}%{_bindir}/pasta.avx2 > > > +rm %{buildroot}%{_bindir}/pasta.avx2 > > > +objcopy --dump-section .note.gnu.build-id=%{buildroot}/build_id %{buildroot}%{_bindir}/passt.avx2 > > > +printf '\x'$(printf %02x $(( ( 0x$(xxd -ps -s 35 %{buildroot}/build_id) + 1 ) % 0xff )) ) | dd of=%{buildroot}/build_id seek=35 bs=1 count=1 conv=notrunc > > > +objcopy --update-section .note.gnu.build-id=%{buildroot}/build_id %{buildroot}%{_bindir}/passt.avx2 %{buildroot}%{_bindir}/pasta.avx2 > > > +rm %{buildroot}/build_id > > > > > > ln -sr %{buildroot}%{_mandir}/man1/passt.1 %{buildroot}%{_mandir}/man1/passt.avx2.1 > > > ln -sr %{buildroot}%{_mandir}/man1/pasta.1 %{buildroot}%{_mandir}/man1/pasta.avx2.1 > > > -install -p -m 755 %{buildroot}%{_bindir}/passt.avx2 %{buildroot}%{_bindir}/pasta.avx2 > > > %endif > > > > > > pushd contrib/selinux > > > -- > > > 2.39.2 > > -- > Stefano -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html