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 F30EA1F4181; Thu, 18 Sep 2025 04:09:11 +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=1758168552; cv=none; b=NUHywVy/+94y7L/NFn6FdNd6TvvirjD3rGxVbuInGnE13E7HciYy05gQNtLS4dtKL912udd32L6uIKbpJpZBD3HoULpWRTVwtaOLHKkNRK2P6+VMyZIaBhAKjsVc8tF3/qWjmQF04DsqoAUP21dvyLUhEapQKx3G9O0VGodnnmM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758168552; c=relaxed/simple; bh=DWbSGaeUDI+94RjG4nVLjU8+xda9a6RkuDCPS0NFvYY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fStaQ5MjH98QJzcTNYf66ijrBM7cnrMLgRy7OFiqmHHAYk1nMCsFK/K7Jzqn+PSC760psJX6NzGxH9aFk+HpmXRPtqw8ia17rWJPRcgDdkCwgWjqo9Bz6+hNj6/WMA3lAa7Oo5DhOiRIsJXr4haHCwcTHWU4Yh977jmfOohnCFo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CeE1FzUU; 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="CeE1FzUU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3FC85C4CEE7; Thu, 18 Sep 2025 04:09:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758168551; bh=DWbSGaeUDI+94RjG4nVLjU8+xda9a6RkuDCPS0NFvYY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CeE1FzUUm9Gp0s0l9dMYuEkT1qY9+hNwzO0zKMfnauL5MIxSYxRxRkQsMcnDF4+eB 4+byZ7+cqmfE8LibXGsNEr1hXDyDnki3WkCPWY2zvwp5AOX+K9+FFXuMQVpdI8ILVB Elo3pDQHPobx5Jgnda8HvFzD5x1EE/mVL5HQ4NXc7emlRYALVJalPxTOJpQCpkx7cA /POob3n1wYHJnxF4wqrNErMCrc6QngfIh9jh4F39f+Hbx3lo6gGxAT5x0hLBr1RbqF T35D94prSMKkEabxTk75EP2UUtxTxGcb5id5V0r3ROuzUPkfrbjbn2381nX15coArj 4I358aDxRP9ww== Date: Thu, 18 Sep 2025 06:08:51 +0200 From: Nicolas Schier To: Alexey Gladkov Cc: Nathan Chancellor , 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Wed, Sep 17, 2025 at 02:38:06PM +0200, Alexey Gladkov wrote: > On Wed, Sep 17, 2025 at 01:55:36PM +0200, Nicolas Schier wrote: > > On Tue, Sep 16, 2025 at 02:42:48PM +0200, Nicolas Schier wrote: > > > On Tue, Sep 16, 2025 at 01:30:20PM +0200, Alexey Gladkov wrote: > > ... > > > > 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 $@ > > > > > > targets += vmlinux > > > > I'd like to suggest another version closer to yours, as mine has several flaws: > > > > diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux > > index dbbe3bf0cf23..9a118b31d0dc 100644 > > --- a/scripts/Makefile.vmlinux > > +++ b/scripts/Makefile.vmlinux > > @@ -87,7 +87,8 @@ remove-section-$(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 > > > > > > > > Rationale (mainly for myself to not walk into that trap too often again): > > > > * Use ';' instead of '&&' as 'cmd_' is evaluated in a 'set -e' > > environment ('cmd') and thus '&&' may hide a possible error exit > > code. > > No, it can't hide exit code. The exit code will be correct even if > ‘set -e’ is not used. > > $ (exit 0) && (exit 2) && (exit 3); echo $? > 2 > > Actually ‘&&’ is protection against the absence of ‘set -e’. That is correct for such a simple command sequence. Putting a compound 'command1 && command2' sequence in a cmd_* macro leads to a mixture of non-comound and compound statements: ( set -e; (exit 0) && (exit 2) && (exit 3); printf 'bye\n' ); echo $? thus we have a case as described in [1, "-e"], so that the exit code 2 gets lost due to the following successful 'printf'. [1]: https://pubs.opengroup.org/onlinepubs/9799919799/utilities/V3_chap02.html#tag_19_26 > > > * Create 'vmlinux' already with the first objcopy and let the second > > one modify it in order to not need a temporary file; iff one or the > > other objcopy exists with an error exit code, the 'set -e + trap' > > ('delete-on-interrupt') shell will remove a possibly existing > > vmlinux file. > > That makes totally sense. This will avoid a temporary file. I will use it > in the new version. > > -- > Rgrds, legion > -- Nicolas