From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/10046 Path: news.gmane.org!not-for-mail From: William Ahern Newsgroups: gmane.linux.lib.musl.general Subject: sockaddr_storage and GCC 6.1 Date: Tue, 24 May 2016 15:07:35 -0700 Message-ID: <20160524220735.GA19259@wilbur.25thandClement.com> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1464127784 16378 80.91.229.3 (24 May 2016 22:09:44 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 24 May 2016 22:09:44 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-10059-gllmg-musl=m.gmane.org@lists.openwall.com Wed May 25 00:09:37 2016 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1b5KW8-0007ad-S2 for gllmg-musl@m.gmane.org; Wed, 25 May 2016 00:09:37 +0200 Original-Received: (qmail 30585 invoked by uid 550); 24 May 2016 22:09:33 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 29921 invoked from network); 24 May 2016 22:07:49 -0000 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=25thandClement.com; h=date :from:to:subject:message-id:mime-version:content-type; s= jan2009; bh=OAE82QTuHGPl2DIsFT0vqfR/+i0=; b=MDIcS3UO/Bi6YGGXCbIS yVw8Ol3+hvswu2GpUAncv3ZCb5HgnJ1TrxFyIG665IdIxWEjcsrBPLphpWm2FJuL URBjSVlZ9wtcetM5+4AdmpZzU+OpjLHRm16jpWOg/LkKOvUvCZw6m7hz0Z6ikrqU u7lF2d/VV5XjpBJnapbuC+U= DomainKey-Signature: a=rsa-sha1; c=nofws; d=25thandClement.com; h=date :from:to:subject:message-id:mime-version:content-type; q=dns; s= jan2009; b=C+E3qWwXr5f/fWk8on98S1mBSyXlYga2J9zZqlNYoQt572eQ7eWOc DQyGzVOqOWvgOO4Bb0lYLzhAKn1e6Y5bKsejFySF8EoaDrpYZImWaVdC9B1YcqEM ZVXz+k3fMxbgN3ocW5JonR1ImrkXiZOd+O5dStgdj5Rx0gpHsQWGVE= Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Xref: news.gmane.org gmane.linux.lib.musl.general:10046 Archived-At: GCC 6.1 more aggressively decomposes aggregate assignments into a series of scalar member assignments. This has uncovered an issue with glibc's layout of struct sockaddr_storage, which has a padding hole from offsets 2 to 8, precisely where .sin_port and .sin_addr are in struct sockaddr_in. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71120 musl shares this same issue. Specifically, the __ss_align member with an 8-byte alignment on LP64 archs. You can track the glibc resolution at https://sourceware.org/bugzilla/show_bug.cgi?id=20111 Or not track it. Reasonable folks can disagree regarding many aspects of this issue, but I thought it worthwhile to bring to people's attention. - Bill