From owner-freebsd-toolchain@FreeBSD.ORG Fri Apr 3 20:39:54 2015 Return-Path: Delivered-To: freebsd-toolchain@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 35FCE9FE; Fri, 3 Apr 2015 20:39:54 +0000 (UTC) Received: from mail-ie0-x22d.google.com (mail-ie0-x22d.google.com [IPv6:2607:f8b0:4001:c03::22d]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id EBBB8F5F; Fri, 3 Apr 2015 20:39:53 +0000 (UTC) Received: by ierf6 with SMTP id f6so97695372ier.2; Fri, 03 Apr 2015 13:39:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc:content-type:content-transfer-encoding; bh=6oDlLOuxwNN1+gyd/RyR+c8tdOuvmY3OJZi46ZBLfN0=; b=MddINJgHPp9WFRsYR0w6UK4+GYlrvPfZAKqIEe0SQ+2y4JTaE97CYlNf2REqBpVR7f tXveuQTIA+4N4JMThJpkC6P6kiij8GMFsUh2W0cJgWEjMEguQlL2t3ixLpB+7zky0iAw kpf3KiwMIplEhzyKpkZAyG3P+t7v4act2eA1ApHhkxxNCzgdIsDdW7W87mrTL2adQ1bq 5bp/C14w9PH8nmJrmqd+BooXdgt1+6VdWD8uQ4PMN3LHqCWpVciu9LhumdVp6nk1ze9k Ga3g2nwt8MXO1SbO4NJXkTLFthf1FQrk3CUEfVxxlwU0x38ficGGU4inzaB4XZmYRxsm 3kGQ== X-Received: by 10.50.28.8 with SMTP id x8mr7233023igg.19.1428093593459; Fri, 03 Apr 2015 13:39:53 -0700 (PDT) MIME-Version: 1.0 Sender: carpeddiem@gmail.com Received: by 10.107.158.19 with HTTP; Fri, 3 Apr 2015 13:39:32 -0700 (PDT) In-Reply-To: <2D2191D4-DB6F-4889-9CA9-DFEE495D8302@bsdimp.com> References: <2D2191D4-DB6F-4889-9CA9-DFEE495D8302@bsdimp.com> From: Ed Maste Date: Fri, 3 Apr 2015 16:39:32 -0400 X-Google-Sender-Auth: 0evGjqvq7s1u4OUwsVBsdGD3qiU Message-ID: Subject: Re: Failed to build rescue with gcc 4.9 To: Warner Losh Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: "freebsd-testing@freebsd.org" , FreeBSD Toolchain X-BeenThere: freebsd-toolchain@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Maintenance of FreeBSD's integrated toolchain List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Apr 2015 20:39:54 -0000 On 3 April 2015 at 13:02, Warner Losh wrote: > That shows that something in the list is needed. Likely only crunchhide. > > It doesn=E2=80=99t tell us why we need it, or when we started needing it,= or what > other conditions we might need it. This information is critical to docume= nt > so we know when we can stop doing it in the future. I=E2=80=99m extremely= reluctant > to commit this until we know these details. Yes, it's crunchide. It was broken prior to r277259: | crunchide: Correct 64-bit section header offset | | For 64-bit binaries the Elf_Ehdr e_shoff is at offset 40, not 44. | Instead of using an incorrect hardcoded offset, let the compiler | figure it out for us with offsetof(). | | Differential Revision: https://reviews.freebsd.org/D1543 It's not completely clear to me why we did not encounter this before; a comment before the erroneous write states: /* * update the offset of section header table in elf * header if needed. */ so I presume something about the object file created by gcc 4.9 causes this code to be executed, while builds using the in-tree compiler did not.