From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 109519 invoked by alias); 9 Oct 2015 23:52:56 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 109507 invoked by uid 89); 9 Oct 2015 23:52:56 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.7 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Fri, 09 Oct 2015 23:52:55 +0000 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id E34BFC0BE068 for ; Fri, 9 Oct 2015 23:52:53 +0000 (UTC) Received: from [10.3.113.151] (ovpn-113-151.phx2.redhat.com [10.3.113.151]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t99NqrDU000302; Fri, 9 Oct 2015 19:52:53 -0400 Subject: Re: [PATCH] gdb: Improve syscall entry/return tracking on Linux To: Pedro Alves , gdb-patches@sourceware.org References: <1444353736-14451-1-git-send-email-jistone@redhat.com> <56179B68.80200@redhat.com> <5617FFF8.50905@redhat.com> <561802C0.8060902@redhat.com> Cc: sergiodj@redhat.com From: Josh Stone Message-ID: <56185354.2080407@redhat.com> Date: Fri, 09 Oct 2015 23:52:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <561802C0.8060902@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2015-10/txt/msg00118.txt.bz2 On 10/09/2015 11:09 AM, Pedro Alves wrote: > On 10/09/2015 06:57 PM, Josh Stone wrote: >> On 10/09/2015 03:48 AM, Pedro Alves wrote: > >>> no-mmu / uclinux systems don't have fork. I'm not sure whether >>> fork returns ENOSYS or SYS_fork isn't even defined there. >>> Maybe just switch to vfork so we can keep catch syscall >>> coverage on those systems? >> >> In kernel/fork.c I see that lacking CONFIG_MMU returns EINVAL. >> >> But it appears a few archs don't implement fork/vfork syscalls at all, >> only clone. > > Ah, yeah. Even on x86 glibc doesn't really implement fork > with the fork syscall. > >> Maybe I should use CLONE_VFORK for broadest coverage? > > That does sound the best. I tried, but this area is fraught with idiosyncrasies. I'm going with a direct vfork() call and loose pattern matching for what syscall results, since I don't actually care about that detail for this test. Hope that works for you.