From patchwork Fri Dec 9 10:59:42 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: pageexec@freemail.hu X-Patchwork-Id: 9467861 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 15F1C607D8 for ; Fri, 9 Dec 2016 11:00:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 06F05283FF for ; Fri, 9 Dec 2016 11:00:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EC2DD285D5; Fri, 9 Dec 2016 11:00:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,FREEMAIL_FROM, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 94D17283FF for ; Fri, 9 Dec 2016 11:00:14 +0000 (UTC) Received: (qmail 25966 invoked by uid 550); 9 Dec 2016 11:00:12 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: kernel-hardening@lists.openwall.com Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 25940 invoked from network); 9 Dec 2016 11:00:10 -0000 From: "PaX Team" To: Kees Cook , Andrew Donnellan Date: Fri, 09 Dec 2016 11:59:42 +0100 MIME-Version: 1.0 CC: "linuxppc-dev@lists.ozlabs.org" , "kernel-hardening@lists.openwall.com" , Emese Revfy , LKML , linux-kbuild , Brad Spengler , Michal Marek Message-ID: <584A8E9E.22035.590FC72@pageexec.freemail.hu> Priority: normal In-reply-to: References: <20161206062800.21800-1-andrew.donnellan@au1.ibm.com>, , X-mailer: Pegasus Mail for Windows (4.72.572) Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Content-description: Mail message body X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.1.12 (r00tworld.com [212.85.137.150]); Fri, 09 Dec 2016 11:59:43 +0100 (CET) X-Virus-Scanned: r00tworld Anti-Virus System Subject: [kernel-hardening] Re: [PATCH 3/3] powerpc: enable support for GCC plugins X-Virus-Scanned: ClamAV using ClamSMTP On 9 Dec 2016 at 13:48, Andrew Donnellan wrote: > >> as for the solutions, the general advice should enable the use of otherwise > >> failing gcc versions instead of forcing updating to new ones (though the > >> latter is advisable for other reasons but not everyone's in the position to > >> do so easily). in my experience all one needs to do is manually install the > >> missing files from the gcc sources (ideally distros would take care of it). > > If someone else is willing to write up that advice, then great. > > >> the specific problem addressed here can (and IMHO should) be solved in > >> another way: remove the inclusion of the offending headers in gcc-common.h > >> as neither tm.h nor c-common.h are needed by existing plugins. for background, > > We can't build without tm.h: http://pastebin.com/W0azfCr0 you'll need to repeat the removal of dependent headers. based on a quick test here across gcc 4.5-6.2, if you remove rtl.h, tm_p.h, hard-reg-set.h and emit-rtl.h in addition to tm.h, the plugins should build fine. > And we get warnings without c-common.h: http://pastebin.com/Aw8CAj10 that's not due to c-common.h. gcc versions 4.5-4.6 are compiled as a C program and gcc 4.7 can be compiled both as a C and a C++ program (IIRC, distros opted for the latter, i forget what manually built versions default to but i guess you went with the C compilation for your gcc anyway). couple that with -Wmissing-prototypes and you get that warning regardless of c-common.h being included. something like this should fix it: > These were all manually built using a script running on a Debian box. > Installing precompiled distro versions of rather old gccs would have > been somewhat challenging. I've just rebuilt 4.6.4 to double check that > I wasn't just seeing things, but it seems that it definitely is still > putting c-common.h in the old location. for reference, this is the git commit that did the move: commit 7bedc3a05d34cd81e4835a2d3ff8c0ec7108eeb5 Author: steven Date: Sat Jun 5 20:33:22 2010 +0000 gcc/ChangeLog: * c-common.c: Move to c-family/. * c-common.def: Likewise. * c-common.h: Likewise. --- a/scripts/gcc-plugins/gcc-generate-gimple-pass.h 2016-12-06 01:01:54.521724573 +0100 +++ b/scripts/gcc-plugins/gcc-generate-gimple-pass.h 2016-12-09 11:43:32.225226164 +0100 @@ -136,6 +136,7 @@ return new _PASS_NAME_PASS(); } #else +struct opt_pass *_MAKE_PASS_NAME_PASS(void); struct opt_pass *_MAKE_PASS_NAME_PASS(void) { return &_PASS_NAME_PASS.pass;