From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 06AB3C77B75 for ; Tue, 23 May 2023 08:01:39 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1q1MxI-0004nk-If; Tue, 23 May 2023 04:01:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1q1MxG-0004ji-M5 for qemu-devel@nongnu.org; Tue, 23 May 2023 04:01:14 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1q1MxE-0001AC-NC for qemu-devel@nongnu.org; Tue, 23 May 2023 04:01:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684828871; h=from:from:reply-to: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=BIB5rKV2YyXJQaMY8AsL4h4OAEln7o6vIZCuxYgaxxA=; b=XZ7rMPwM/3Vk6QDV4E3X1ZqGUNSWjuPPUcVGok/q3BegitpFP3xI1iIRmAO9QWA0WPxvyk rNPbzwhBk6j9ERVwxzAt0v5atAKSrihxG6lrv6JkgYgfvEBC8y7mJgcMRGgxhMXRf2Ojwb KpjizvIOe9ubte4yEOqfwc76wwJTbTc= 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-195-lidiXEX-NGS5WxPLOrJ48g-1; Tue, 23 May 2023 04:00:53 -0400 X-MC-Unique: lidiXEX-NGS5WxPLOrJ48g-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4B4E5811E8E; Tue, 23 May 2023 08:00:53 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.40]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4CAB49D73; Tue, 23 May 2023 08:00:52 +0000 (UTC) Date: Tue, 23 May 2023 09:00:50 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Paolo Bonzini Cc: qemu-devel@nongnu.org, vr_qemu@t-online.de, marcandre.lureau@redhat.com Subject: Re: [PATCH] meson: remove -no-pie linker flag Message-ID: References: <20230522080816.66320-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230522080816.66320-1-pbonzini@redhat.com> User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, May 22, 2023 at 10:08:16AM +0200, Paolo Bonzini wrote: > The large comment in the patch says it all; the -no-pie flag is broken and > this is why it was not included in QEMU_LDFLAGS before commit a988b4c5614 > ("build: move remaining compiler flag tests to meson", 2023-05-18). > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1664 > Signed-off-by: Paolo Bonzini > --- > meson.build | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/meson.build b/meson.build > index 0a5cdefd4d3d..6733b2917081 100644 > --- a/meson.build > +++ b/meson.build > @@ -267,10 +267,15 @@ endif > # has explicitly disabled PIE we need to extend our cflags. > if not get_option('b_pie') > qemu_common_flags += cc.get_supported_arguments('-fno-pie') > - if not get_option('prefer_static') > - # No PIE is implied by -static which we added above. > - qemu_ldflags += cc.get_supported_link_arguments('-no-pie') > - endif > + # What about linker flags? For a static build, no PIE is implied by -static > + # which we added above. For dynamic linking, adding -no-pie is messy because > + # it overrides -shared: the linker then wants to build an executable instead > + # of a shared library and the build fails. Before moving this code to Meson, > + # we went through a dozen different commits affecting the usage of -no-pie, > + # ultimately settling for a completely broken one that added -no-pie to the > + # compiler flags together with -fno-pie... except that -no-pie is a linker > + # flag that has no effect on the compiler command line. So, don't add > + # -no-pie anywhere and cross fingers. > endif I'm curious why we need to do anything ? I would have thought that meson should handle 'b_pie' itself, passing the right args to $CC that it feels are appropriate. I don't recall seeing other apps using meson trying to handle b_pie logic - what's special about QEMU ? IOW, is it possible to delete this entire b_pie condition and thus avoid worrying about this problem ? With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|