From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E38282D949A; Tue, 16 Sep 2025 13:35:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758029757; cv=none; b=jMTdbZYFbJGWW20K8gSp8GHWl98CPeGACCAI5BbPF9RjEIw2QnJKMFlhC5vMJzP5FMbCe/lEPqwzST+le0oTZpfsatdxi1SZFcxySntMrgKtgGp5SZ73Blz56RJrJIvLIlCOD7CFX2Y8CdG156dkA5bmjyD94qP9UFSBmQQY6O4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758029757; c=relaxed/simple; bh=rTIf/MtovWp08QtcwAXtxQE4sn7DYFAtPPui+rgyT68=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AVssb+9UFeZRkncd8uG658ABa8YlOqidsucsPyxzG01Zy+1khxkB+CRBcerDAsBkN4+OCEB0rAk2DLGgoFP0sHv3kRCgVFjpuqTkC73ip5+atJVkY985z0xOAQrfbY4lDy6gs2LqHJ/NdNhoeucYU40kPD3ez3hQge6qpDZHZBE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=opmALYIO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="opmALYIO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 303BAC4CEEB; Tue, 16 Sep 2025 13:35:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758029756; bh=rTIf/MtovWp08QtcwAXtxQE4sn7DYFAtPPui+rgyT68=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=opmALYIOTGquTTpyU9Zv1RIgrv6kVHyx71VOlnhl4dDx77Ov0DpgS1ZbSi+65yawE b7DaPsIYnxg4h1HSkn09uv3txs9c3+kbk2Qh1w3K4lhwfrjIYazqQq3jaURjP4+azR h0EATQWG4Vxh+Wm8mWtdzXrYjso/0kGOk7gyhw4R2bqhh0mnYIiJut/yfACo8AFOAH Ry/BQH2RtiJXWraQ5o8Vku+JlsUnffWce9xOISmXT25ZWaVkiooiLffEkrqEunHLrR eWebWl+C5sfyV7CsjV91XoKDn4Kq3hypEBqfxyXvrmGZhJ8owdinMVzNtwQOgxqNXj Ie0yyA3nvNypg== Date: Tue, 16 Sep 2025 15:28:09 +0200 From: Nicolas Schier To: Alexey Gladkov , Nathan Chancellor Cc: Petr Pavlu , Luis Chamberlain , Sami Tolvanen , Daniel Gomez , linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org, linux-kbuild@vger.kernel.org, Masahiro Yamada Subject: Re: [PATCH v7 3/8] kbuild: keep .modinfo section in vmlinux.unstripped Message-ID: References: <4d53c72293d88b663257a0d723ebf3473a08b374.1755535876.git.legion@kernel.org> Precedence: bulk X-Mailing-List: linux-modules@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Sep 16, 2025 at 03:03:46PM +0200, Alexey Gladkov wrote: > On Tue, Sep 16, 2025 at 02:42:48PM +0200, Nicolas Schier wrote: > > > > > > Hi Alexey, > > > > > > > > > > > > with this patch applied, I still get a warning from objcpy as Masahiro > > > > > > and Stephen wrote [1,2] > > > > > > > > > > > > SORTTAB vmlinux.unstripped > > > > > > + sorttable vmlinux.unstripped > > > > > > + nm -S vmlinux.unstripped > > > > > > + ./scripts/sorttable -s .tmp_vmlinux.nm-sort vmlinux.unstripped > > > > > > + is_enabled CONFIG_KALLSYMS > > > > > > + grep -q ^CONFIG_KALLSYMS=y include/config/auto.conf > > > > > > + cmp -s System.map .tmp_vmlinux2.syms > > > > > > + echo vmlinux.unstripped: ../scripts/link-vmlinux.sh > > > > > > # OBJCOPY vmlinux > > > > > > objcopy --remove-section=.modinfo vmlinux.unstripped vmlinux > > > > > > objcopy: vmlinux.unstripped: warning: empty loadable segment detected at vaddr=0xffff8000807a0000, is this intentional? > > > > > > > > > > > > (arm64, allnoconfig) > > > > > > > > > > > > Kind regards, > > > > > > Nicolas > > > > > > > > > > > > > > > > > > [1]: https://lore.kernel.org/linux-kbuild/CAK7LNAR-gD2H6Kk-rZjo0R3weTHCGTm0a=u2tRH1WWW6Sx6=RQ@mail.gmail.com/ > > > > > > [2]: https://lore.kernel.org/lkml/20250730164047.7c4a731a@canb.auug.org.au/ > > > > > > > > > > > > > > > > Hm. I missed that. I need to investigate how to fix this. Nothing comes > > > > > to mind right now. > > > > > > > > Same here. Only thing I could find until now is > > > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/diff/scripts/link-vmlinux.sh?id=90ceddcb495008ac8ba7a3dce297841efcd7d584 > > > > > > > > where '2>/dev/null' is appended exactly to prevent this very warning. > > > > But for me, it doesn't feel good doing that when stripping to vmlinux. > > > > > > Yes, that's not a very good approach. It will hide other errors that will > > > definitely need to be seen. I think the commit you mentioned is actually > > > incorrect. I think there should be a different solution. > > > > > > I think in the case of .modinfo, we can change the flag in the section > > > since we are going to delete it anyway. > > > > > > diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux > > > index dbbe3bf0cf23..9a118b31d0dc 100644 > > > --- a/scripts/Makefile.vmlinux > > > +++ b/scripts/Makefile.vmlinux > > > @@ -87,7 +87,8 @@ remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' > > > remove-symbols := -w --strip-symbol='__mod_device_table__*' > > > > > > quiet_cmd_strip_relocs = OBJCOPY $@ > > > - cmd_strip_relocs = $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) \ > > > + cmd_strip_relocs = $(OBJCOPY) $(patsubst %,--set-section-flags %=noload,$(remove-section-y)) $< && \ > > > + $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) \ > > > $(remove-symbols) $< $@ > > > > > > targets += vmlinux > > > > Ah, great! I thought we had to fiddle around with linker scripts et al. > > I needed to use an intermediate file: > > > > diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux > > index e2ceeb9e168d..516d51ca634b 100644 > > --- a/scripts/Makefile.vmlinux > > +++ b/scripts/Makefile.vmlinux > > @@ -90,6 +90,9 @@ remove-section-y := .modinfo > > remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' > > > > quiet_cmd_strip_relocs = OBJCOPY $@ > > - cmd_strip_relocs = $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) $< $@ > > + cmd_strip_relocs = set -e; \ > > + trap 'rm $<.noload' EXIT HUP INT; \ > > + $(OBJCOPY) $(patsubst %,--set-section-flags %=noload,$(remove-section-y)) $< $<.noload && \ > > + $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) $<.noload $@ > > > > targets += vmlinux > > according to man-page: > > If you do not specify outfile, objcopy creates a temporary file and > destructively renames the result with the name of infile. > > That is true even in freebsd: > > https://man.freebsd.org/cgi/man.cgi?query=objcopy > > Do you want to support any other objcopy implementations ? yeah, it's actually because I dislike modifying vmlinux.unstripped in the vmlinux rule. But it may be that Nathan does not see it this way. -- Nicolas