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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id B2760C88E72 for ; Thu, 17 Sep 2026 14:41:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=AcGlwILbAigYPbHp2UpTCzPJPin2iJgiGFZE+fP0U6A=; b=1Hb/irNl8uQY6zVKc5bWKX+11P YjXgacDmTPVCITNtGOt2IMkeVdYzjzUyMLcHWiM16bnZrsPtlTua8OWOBzZnLqEO/JUM5erNoK1bb WXYGD87vYdzKiwYOVtVcgB0umMDYqFaT7wqarffvRdiu2+DlRZ1m8pjPDTjMS1Ty7I2v5yyzLYQHS yP4bRryzmg9huHhXw53KtPqsuUOKQiwZQRHMowaYeFfdCPfKO2Sa0ofx+CmtYL10voFpsAth9UHTi 9WKs3hJK+OkA23O5GzbuHWID4XDNHJ03AS03qTLgl5rry0FlyZGfWwPRZUNgEf25jTm1aNSHJHPul eNr/hRIQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x7DIt-0000000BZ9a-23Ck; Thu, 17 Sep 2026 14:41:35 +0000 Received: from fanzine2.igalia.com ([213.97.179.56]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x7DIq-0000000BZ8Z-0Yg0 for linux-arm-kernel@lists.infradead.org; Thu, 17 Sep 2026 14:41:33 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:From:Cc:To:Subject: MIME-Version:Date:Message-ID:From:Reply-To; bh=AcGlwILbAigYPbHp2UpTCzPJPin2iJgiGFZE+fP0U6A=; b=KL9WhOlAUJRZ5QgUzNtZiS8IlH pkxe8NN+TZJcfiAZ5s+JwvNtO+7Ez7pcbfVvCqKU/7JgCTILNHEiKwicbxaW0ivRJomjNkyAkLCXD aXrAYB1ZO5XaFp2bW4wK0s4DYGRZnyAJcdCV7Zyrw5ZvWVjpA0TefVpzNB9OX01R9pciJVeiVLCaZ 0hkZEkTT4t2ZBzL2i+Z7o66ud062Czqazrrf8RKuUgQjfBK+DU28gy8hvFL8MZ9/gYtXh4yXt06Pj MuKxucN0l1CdGykw2Up7LWD73GQ35lBs0Xgvpsw8L7YzJzgEorjCui9h3xvRexJ78+aLTqQzzISpt F2NpTMWA==; Received: from [177.172.123.214] (helo=[192.168.15.100]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1x7DIa-003U2s-A4; Thu, 17 Sep 2026 16:41:16 +0200 Message-ID: <23596300-b89e-4cff-a6ce-e7bf54e90c05@igalia.com> Date: Thu, 17 Sep 2026 11:41:15 -0300 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 4/4] arm64: vdso32: Implement __vdso_futex_robust_try_unlock() To: Mark Rutland Cc: Catalin Marinas , Will Deacon , Thomas Gleixner , Mathieu Desnoyers , Sebastian Andrzej Siewior , Peter Zijlstra , Florian Weimer , Darren Hart , Ingo Molnar , Davidlohr Bueso , Arnd Bergmann , Uros Bizjak , =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?= , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, kernel-dev@igalia.com References: <20260821-tonyk-robust_arm-v8-0-077707b6f1c7@igalia.com> <20260821-tonyk-robust_arm-v8-4-077707b6f1c7@igalia.com> Content-Language: en-US From: =?UTF-8?Q?Andr=C3=A9_Almeida?= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260917_074132_181858_252DEFFE X-CRM114-Status: GOOD ( 11.91 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Em 17/09/2026 07:50, Mark Rutland escreveu: > On Wed, Sep 16, 2026 at 10:11:01PM -0300, André Almeida wrote: >> Em 16/09/2026 11:28, Mark Rutland escreveu: >>> On Fri, Aug 21, 2026 at 06:50:45PM -0300, André Almeida wrote: >>>> Based on aarch64 implementation, provide a 32 bit entry point for >>>> this vDSO. >>>> >>>> In order to keep compatibility with arm64_futex_robust_unlock_get_pop(), >>>> make sure to store the pop address at r2 and the compare result value >>>> at r3. >>> >>> Before we add this to the compat vdso, we'll need to implement this on >>> arch/arm/. >>> >>> Otherwise, my comments on the patch for the native vdso functions apply >>> here too. >> >> Right, and the compat entry point at arch/arm64/ would point to the >> __vdso_futex_robust_list32_try_unlock implementation at arch/arm/? > > So far we've had arm64 provide its own copy (which e.g. might use > sequences relying on ARMv8+ instructions), so I think we'd do the same > here. > > The key thing is that 32-bit tasks on arm64 should see the same ABI as > native tasks on 32-bit arm. As there's a risk that 32-bit arm might have > some ABI quirks (e.g. due to older processors), we don't want to enable > features for compat tasks on arm64 before that's been implemented on > 32-bit arm. Gotcha, makes perfect sense. Thanks! André