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=-3.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=unavailable 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 0FE79C10F11 for ; Wed, 24 Apr 2019 16:23:59 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 D1D83208E4 for ; Wed, 24 Apr 2019 16:23:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="FExVwg5g" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D1D83208E4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID: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=CWW98Ms2juw93iSomOiZhioYxeGGhdpd78iBNgbWSxI=; b=FExVwg5geQB6q/ EuVmBOttcmWLeIG0JkgTbEHGMOYwlnwXUX7t/nEBUcMA/cDynR6Kh0Th9Uv7xXvpn9+tz5HjwTYkd kFhSWcM/I+HJ8Ey395HVvpVoyV7eqkFhVKsHKwZcJUfzwIm8jLO5m62BA8BmKAFbkUPYYifHC9/n7 WOMvnp5Pq5v/JGK5cq10sKValmmVpYX4G10f6TqfV1UQiPnao0xy6uCQtGc/QEOb4HUMeMQxmAwkE Nb4gB3lICoVvo+dwdsaJdnYCz0AnMr06hti6nnR/6cL7NqeJ1spAq61uCFXbroKQS6PKSrGgs4xD9 CLtYJ1HpooDt4di0urzQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hJKgc-0008Qg-9l; Wed, 24 Apr 2019 16:23:54 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hJKgB-00082G-Ni for linux-arm-kernel@lists.infradead.org; Wed, 24 Apr 2019 16:23:31 +0000 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4702F30C45BC; Wed, 24 Apr 2019 16:23:27 +0000 (UTC) Received: from treble (ovpn-123-99.rdu2.redhat.com [10.10.123.99]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 678A7600C1; Wed, 24 Apr 2019 16:23:26 +0000 (UTC) Date: Wed, 24 Apr 2019 11:23:24 -0500 From: Josh Poimboeuf To: Raphael Gault Subject: Re: [RFC 2/6] objtool: arm64: Add required implementation for supporting the aarch64 architecture in objtool. Message-ID: <20190424162324.36xn7aepuggyvbzi@treble> References: <20190409135243.12424-1-raphael.gault@arm.com> <20190409135243.12424-3-raphael.gault@arm.com> <20190423201823.fnddnyxpu64jnlgp@treble> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Wed, 24 Apr 2019 16:23:27 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190424_092328_088704_A5E5FDAA X-CRM114-Status: GOOD ( 24.10 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Julien Thierry , "peterz@infradead.org" , Catalin Marinas , Will Deacon , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Apr 24, 2019 at 04:16:26PM +0000, Raphael Gault wrote: > On 4/23/19 9:18 PM, Josh Poimboeuf wrote: > > On Tue, Apr 09, 2019 at 02:52:39PM +0100, Raphael Gault wrote: > >> Provide implementation for the arch-dependent functions that are called by the main check > >> function of objtool. > >> The ORC unwinder is not yet supported by the arm64 architecture so we only provide a dummy > >> interface for now. > >> The decoding of the instruction is split into classes and subclasses as described into > >> the Instruction Encoding in the ArmV8.5 Architecture Reference Manual. > > > > Where did the code for the decoder come from? Was it written from > > scratch? > > > > This decoder was indeed written from scratch based on the armv8 ARM. The > automatic generation idea hasn't really been discussed yet. Ok. That's a lot of code. Hopefully ARM folks can review it closely. > >> +#ifndef __ASSEMBLY__ > >> +/* > >> + * This struct is more or less a vastly simplified version of the DWARF Call > >> + * Frame Information standard. It contains only the necessary parts of DWARF > >> + * CFI, simplified for ease of access by the in-kernel unwinder. It tells the > >> + * unwinder how to find the previous SP and BP (and sometimes entry regs) on > >> + * the stack for a given code address. Each instance of the struct corresponds > >> + * to one or more code locations. > >> + */ > >> +struct orc_entry { > >> +s16sp_offset; > >> +s16bp_offset; > >> +unsignedsp_reg:4; > >> +unsignedbp_reg:4; > >> +unsignedtype:2; > >> +unsignedend:1; > >> +} __packed; > >> + > >> +/* > >> + * This struct is used by asm and inline asm code to manually annotate the > >> + * location of registers on the stack for the ORC unwinder. > >> + * > >> + * Type can be either ORC_TYPE_* or UNWIND_HINT_TYPE_*. > >> + */ > >> +struct unwind_hint { > >> +u32ip; > >> +s16sp_offset; > >> +u8sp_reg; > >> +u8type; > >> +u8end; > >> +}; > >> +#endif /* __ASSEMBLY__ */ > >> + > >> +#endif /* _ORC_TYPES_H */ > > > > It seems odd to have the above header file in arm64 code, since it > > doesn't implement ORC. Is it really needed? > > > > The unwind_hint part can safely be removed. However the orc_entry seems > to be needed since the struct instruction comports a struct orc_entry > field. I have chosen to let it here as well but maybe a better approach > is possible. Ideally we can figure out a way to decouple 'struct instruction' from 'struct orc_entry'. But yes, I think your approach is fine for now. Though I think using an arch-independent header file would be better, to avoid creating duplicated (dead) code. -- Josh _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel