From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C650C433DF for ; Tue, 7 Jul 2020 21:32:17 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 48D49206BE for ; Tue, 7 Jul 2020 21:32:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="MlW+ECmZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 48D49206BE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-snps-arc-bounces+linux-snps-arc=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:Message-ID:In-Reply-To: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+Uw3XXphuvQdFLSCWEaNFuipLjufKoaV22hLapzXtFE=; b=MlW+ECmZrH1Tx2sw1wxI04FuW EQXmmeOmLrjQWRcAyBJjcgjZElpes3b1B1BJ8BKP29iEXEXkrz9kDJmr2Xo+ogPcV1DgRlPK8XaOH qOCiD4AYm75J44huiceovGkwqy15jUlmdYkbyBozn2/GBZD6qXtfkrroYfnEKpNV7rWSuoOETY9L5 zg01rUH/TpSe9DWcIVKlvZnfLL4J0gg9+Ea5u5kmC/cyjCd20E4Qmm8BwxOVH7/ug78Dk3zhK1mWL UIUesTqPjfU3YpXwhAqZ/2g48Fpcs8d1QnV+DTV2a9HD2+vbXyTio88A24qAV8w4utZSL1AxKCGZ9 0CyJq/1qQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jsvCK-0008KB-PE; Tue, 07 Jul 2020 21:32:16 +0000 Received: from esa4.mentor.iphmx.com ([68.232.137.252]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jsvCI-0008JK-8P for linux-snps-arc@lists.infradead.org; Tue, 07 Jul 2020 21:32:15 +0000 IronPort-SDR: 1AWqyW0YQDwsJ0tKB64HJ3+AHNuav049C8AgGH/0Rn+TsiQRVR7D8cRDqYRPf8bkKRSo6YC/iz c7rQ4z4ah24/S/TiwUl170yCNhxEyUYpzp8KDldwB6l+Vng07CiZ7C5zYfz9V/YFQX+7qtwLOd b3p23T9KW4dJ/2trikNzxtGNBt8CKmH1MFng162GUdP1hpJnRMAcJZyrU8tbECV3crN1rqoSGq o9mR5MDS6GJ9F4XFGa6Xwc+oHVfuowpqN90/zfQYmlfUIUQ786r9AOLR3008FqKMS3IwzI0tGw 5OE= X-IronPort-AV: E=Sophos;i="5.75,325,1589270400"; d="scan'208";a="50810128" Received: from orw-gwy-02-in.mentorg.com ([192.94.38.167]) by esa4.mentor.iphmx.com with ESMTP; 07 Jul 2020 13:32:13 -0800 IronPort-SDR: SyUIB12rlJ6I0V9ctfBzzQFv19z4561EpqTt/56JzpZB8N/+cuJA0ynzBeF9vZc9WrBTquvLHq 0eBdT+ewRTwDZvwCSLzt8tbzmn2wkIlGS3bGf2b0+N39k+GkLeFWIKNoxk6972EW9QUYOz+KmV XY9oJEaGsAQeKvFfk1J7EPGYll/iBFzXnaLoAXahhO7rvQvH9MezqChaNZC337lEEz98HlJOLA 3sQYg6lNqhqxqqpkvjw/tcX31q+a22C9I8pJm/W0RgDOxgZC8M8OlDv9LJuc1iARwcK0BTTqHi AQ0= Date: Tue, 7 Jul 2020 21:32:07 +0000 From: Joseph Myers X-X-Sender: jsm28@digraph.polyomino.org.uk To: Vineet Gupta Subject: Re: [PATCH v7.1 07/13] ARC: Linux Syscall Interface In-Reply-To: <0e3bf658-10b4-0428-02f3-f2ae01c77ddf@synopsys.com> Message-ID: References: <20200615201441.31820-8-vgupta@synopsys.com> <20200701000848.20492-1-vgupta@synopsys.com> <64e18e52-9dc6-6d14-3e15-8c5ff1c0cdc2@synopsys.com> <5feda452-d571-2ffb-5cb4-a71dc7033503@synopsys.com> <8ec1c7a1-dd77-5f1f-a2a4-11d214152a0d@linaro.org> <0e3bf658-10b4-0428-02f3-f2ae01c77ddf@synopsys.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: svr-ies-mbx-02.mgc.mentorg.com (139.181.222.2) To SVR-IES-MBX-03.mgc.mentorg.com (139.181.222.3) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200707_173214_446626_D89CFECD X-CRM114-Status: GOOD ( 11.58 ) X-BeenThere: linux-snps-arc@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on Synopsys ARC Processors List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: arcml , "libc-alpha@sourceware.org" , Adhemerval Zanella Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+linux-snps-arc=archiver.kernel.org@lists.infradead.org On Tue, 7 Jul 2020, Vineet Gupta via Libc-alpha wrote: > > Each implementation has it ows requirements so I can't really say if > > a helper function does make sense for all of them. For pause > > specifically we can even simplify to since all architectures have > > either ppoll or ppoll_time64: > > > > int > > __libc_pause (void) > > { > > #ifdef __NR_ppoll_time64 > > return SYSCALL_CANCEL (ppoll_time64, NULL, 0, NULL, NULL); > > #else > > return SYSCALL_CANCEL (ppoll, NULL, 0, NULL, NULL); > > #endif > > } > > But how is this compatible with older kernels (and perhaps this is a general > question). I mean one/more ABIs minimum kernel would not have the ppoll or ppoll64 > so how will new glibc work with such a kernel ? Is it not required to ? See commit 089b772f98afd9eb6264c6489bc96a30bf6af4ac, where I removed __ASSUME_PPOLL because all supported kernel versions now had that syscall for all glibc architectures. In general this sort of thing needs a review of whether a given syscall is available for all glibc architectures in their minimum kernel versions. For the old kernels in question, that means checking the architecture-specific syscall table as used to dispatch syscalls at runtime, which used to have an architecture-specific format before unification work was done; it used to mean checking asm/unistd.h as well, but now we have syscall tables in glibc that's probably no longer required. It also involves checking compat syscall tables for 32-bit binaries on 64-bit kernels, as sometimes a syscall didn't get added to the native and compat syscall tables at the same time (see the comments in sparc/kernel-features.h about various socket-related syscalls, for example). -- Joseph S. Myers joseph@codesourcery.com _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc