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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77692C433F5 for ; Tue, 5 Oct 2021 12:20:03 +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 459C46120D for ; Tue, 5 Oct 2021 12:20:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 459C46120D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arndb.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; 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Tue, 05 Oct 2021 05:18:06 -0700 (PDT) X-Gm-Message-State: AOAM532gV8ABFbOX5DzK3Az6J4uzn8F6yXCrDEo/UFPw7b2bfMCVXAQX BIFbLrcA1005lxUqmnU+JvTF9LXYyy2YTgh1o1E= X-Google-Smtp-Source: ABdhPJxzMnguq47DRmqxglxaZPrPDIv0ExwF8Qei+HWGCzEIwQuNNNySvh1q4myU3FliuExP2g53mszaJuNCQb7iOjE= X-Received: by 2002:a7b:c24c:: with SMTP id b12mr3082204wmj.173.1633436286016; Tue, 05 Oct 2021 05:18:06 -0700 (PDT) MIME-Version: 1.0 References: <20211005071542.3127341-1-ardb@kernel.org> <20211005071542.3127341-5-ardb@kernel.org> In-Reply-To: <20211005071542.3127341-5-ardb@kernel.org> From: Arnd Bergmann Date: Tue, 5 Oct 2021 14:17:50 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 4/9] ARM: unwind: support unwinding across multiple stacks To: Ard Biesheuvel Cc: Linux ARM , Russell King - ARM Linux , Arnd Bergmann , Kees Cook , Keith Packard , Linus Walleij X-Provags-ID: V03:K1:6p/7q9GTcVQSrUPaOaKAqVjTDuKQZAHIWCT+smAmugD6kGAcMFB woUKtYoe7LBZJ4vx2QCZ5EBIgk6NWptU5CnZlI437hzNezPmPTe80ScyGenRMQrAFL25clU cd8gRFWkG9Dr5Lf1QhNWtIJNqE2qd7KdNqqvu33HgbTr2WCSMVwKdEPq0VEEfchuPN7D6tX yoIVjMvoWjsQI4hOLWJrQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:19UdIdmhVjA=:lCHQtizdtbwjvmcU4Fsb+a BSJ0BCZjM3D46gXxXG+nWoWIPskoPOotbXtXSqpK3NKyLp2mGB8YUzb3qDbaT18SVxZ/Z5KZ9 kVv82guKdJ9Krtvkvq3kjgqvOno5R6CN6iz2V0LvZyznFJRU91N/RHMoNYA+Ax/DIyIZgMKvH ZxG5k6wNe29uWeWJw8cFxZMb8D31tXyFxRcS1otwmwtljbnPqXSn57uubaF1v9mMhsTth/Liy NtVs8Rxo0Dzk/DoKARw+zlF8PZzxBsrWkB+JxHrbtlRVSFfeuHb6JnWBXsXXqq+mbcBXTewvp rRB0Gcdw8z3Sl5c9w3v4+fdVX3AL88N1UGHiiNu1mPvc9S/8UWAqoA408nWjDqnMZ/NnTg5im iUcphdbhVqDPDniheU1NB9KgBq1SeWw4Jvf7Bpjio7DDbazPdQOV0hMWQzvx/RcDaG2Gx6neF dqqFV0YSzvHTkV5AX/NTCISMal8UKtAWeaL+kAItebExLp7vKdDHPoNif8vyD5Um58585jmyV eVm6Y57QtVqgs47NZi/3P6z/VLmicErGcZde2DR5pSb3pwMZVvyIYiTguNZz9v/Fev89qL7v6 aENC33ZfmV6stiFHR+Ux7ZNIc1KkxbXWRTJHdxB8V6fQ37/+72r9Zmmjc20Tpq3ERJQRkODwI EPaYDp/cxinu040tDg8+8dJWpYZmjEYjIEAPdL+NoxpaXuVFj0fYZf1YJkjyjt90rIHdpp+KP aPtSZu7cawgPhsGjk96zusKAqGVur+JrK5OTGQFmadIyM/sNiKbq6jZZMO22yT3ghkY3iilxW H1b/6gim6WwkM9+O1zNLPeQGuvx3URwtvlTks3Ei7JQa2uoOP3ehLlomkaNIonprpchjG5yN8 S3HgJTbEBq3yTpjfA/zw== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211005_051808_840117_E172024B X-CRM114-Status: GOOD ( 19.78 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Oct 5, 2021 at 9:15 AM Ard Biesheuvel wrote: > > Implement support in the unwinder for dealing with multiple stacks. > This will be needed once we add support for IRQ stacks, or for the > overflow stack used by the vmap'ed stacks code. > > This involves tracking the unwind opcodes that either update the virtual > stack pointer from another virtual register, or perform an explicit > subtract on the virtual stack pointer, and updating the low and high > bounds that we use to sanitize the stack pointer accordingly. > > Signed-off-by: Ard Biesheuvel I can't say I understand the code in detail, but I see nothing wrong here either. Reviewed-by: Arnd Bergmann > - else if ((insn & 0xf0) == 0xa0) { > + ctrl->sp_low = ctrl->vrs[SP]; > + ctrl->sp_high = ALIGN(ctrl->sp_low, THREAD_SIZE); > + } else if ((insn & 0xf0) == 0xa0) { Would this break if the IRQ stack is not aligned to THREAD_SIZE? If it would, it may be good to document this somewhere, probably in patch 7, not here. Arnd _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel