From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id KyOfF2UdnGBrYwAAWB0awg (envelope-from ) for ; Wed, 12 May 2021 14:24:37 -0400 Received: by simark.ca (Postfix, from userid 112) id 53A4D1F11C; Wed, 12 May 2021 14:24:37 -0400 (EDT) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=MAILING_LIST_MULTI, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 98C741E783 for ; Wed, 12 May 2021 14:24:36 -0400 (EDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 59D153853823; Wed, 12 May 2021 18:24:36 +0000 (GMT) Received: from rock.gnat.com (rock.gnat.com [IPv6:2620:20:4000:0:a9e:1ff:fe9b:1d1]) by sourceware.org (Postfix) with ESMTP id 4D7143853801 for ; Wed, 12 May 2021 18:24:33 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 4D7143853801 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=adacore.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=tromey@adacore.com Received: from localhost (localhost.localdomain [127.0.0.1]) by filtered-rock.gnat.com (Postfix) with ESMTP id E0DDA5618E; Wed, 12 May 2021 14:24:32 -0400 (EDT) X-Virus-Scanned: Debian amavisd-new at gnat.com Received: from rock.gnat.com ([127.0.0.1]) by localhost (rock.gnat.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id zIxSmhWMNWf3; Wed, 12 May 2021 14:24:32 -0400 (EDT) Received: from murgatroyd (75-166-134-27.hlrn.qwest.net [75.166.134.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by rock.gnat.com (Postfix) with ESMTPSA id 90BEB560FE; Wed, 12 May 2021 14:24:32 -0400 (EDT) From: Tom Tromey To: Pedro Alves Subject: Re: [PATCH] Don't run personality syscall at configure time; don't check it at all References: <20210506224341.398202-1-pedro@palves.net> X-Attribution: Tom Date: Wed, 12 May 2021 12:24:31 -0600 In-Reply-To: <20210506224341.398202-1-pedro@palves.net> (Pedro Alves's message of "Thu, 6 May 2021 23:43:41 +0100") Message-ID: <87r1ib6c9s.fsf@tromey.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: gdb-patches@sourceware.org Errors-To: gdb-patches-bounces@sourceware.org Sender: "Gdb-patches" >>>>> "Pedro" == Pedro Alves writes: Pedro> "man 2 personality" says: Pedro> This system call first appeared in Linux 1.1.20 (and thus first Pedro> in a stable kernel release with Linux 1.2.0); library support Pedro> was added in glibc 2.3. Pedro> ... Pedro> ADDR_NO_RANDOMIZE (since Linux 2.6.12) Pedro> With this flag set, disable address-space-layout randomization. Pedro> glibc 2.3 was released in 2002. Pedro> Linux 2.6.12 was released in 2005. It turns out that this caused the build to fail on RH ES5. Address space randomization works fine there, and 'personality' exists -- but ADDR_NO_RANDOMIZE is only defined in , not . I have a patch to work around this by restoring this check: Pedro> - AC_CHECK_DECLS([ADDR_NO_RANDOMIZE],,, [#include ]) ... and the corresponding define in nat/linux-personality.c. (I tried just including the linux/ header but it doesn't declare 'personality'.) I don't know if anybody else cares about this old system. If so, let me know and I can send the patch. Otherwise I may not bother. thanks, Tom