From patchwork Wed Sep 11 22:28:28 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ralph Campbell X-Patchwork-Id: 11142193 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C749E76 for ; Thu, 12 Sep 2019 04:15:08 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 AE4AB21D79 for ; Thu, 12 Sep 2019 04:15:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AE4AB21D79 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6C40D6EC17; Thu, 12 Sep 2019 04:12:50 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from hqemgate14.nvidia.com (hqemgate14.nvidia.com [216.228.121.143]) by gabe.freedesktop.org (Postfix) with ESMTPS id BE63A6E0E2; Wed, 11 Sep 2019 22:28:50 +0000 (UTC) Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Wed, 11 Sep 2019 15:28:51 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Wed, 11 Sep 2019 15:28:49 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Wed, 11 Sep 2019 15:28:49 -0700 Received: from HQMAIL109.nvidia.com (172.20.187.15) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 11 Sep 2019 22:28:46 +0000 Received: from hqnvemgw01.nvidia.com (172.20.150.20) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Wed, 11 Sep 2019 22:28:46 +0000 Received: from rcampbell-dev.nvidia.com (Not Verified[10.110.48.66]) by hqnvemgw01.nvidia.com with Trustwave SEG (v7, 5, 8, 10121) id ; Wed, 11 Sep 2019 15:28:46 -0700 From: Ralph Campbell To: Subject: [PATCH 3/4] mm/hmm: allow hmm_range_fault() of mmap(PROT_NONE) Date: Wed, 11 Sep 2019 15:28:28 -0700 Message-ID: <20190911222829.28874-4-rcampbell@nvidia.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190911222829.28874-1-rcampbell@nvidia.com> References: <20190911222829.28874-1-rcampbell@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1568240931; bh=F20+CtE96DKxf8E9hC0a2S8wRPS9i4pdaXNv/ANnE1k=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Type:Content-Transfer-Encoding; b=EHV8pR7Vx2o54VOBe9IiUlPWtdqX1Bc/1/UKUEx3gpEMFs7hfOIwd/89RCnmdNqV/ JxxnSfJKv+Lv+A9hv5TtPCiEQ7UeRyHgPP165+7aebwpPZ/iuE5m1lagJtleznsAgb RHcAoxNlxawV83OHZC8z8vwpSD7eV3fSD9HWbJry61FPhtIbRFOvFpre4bIrcVubvC GxD2YwE9TkX0WYagYzw0Ma0JO1W415YxmhSJPW4Tmhkep2I5j2pnJF1VDhbJCdi4RH Y6nNbO/Sh8DurJ3DJPCtvHqf0hRlvIlYyO3ePZLlK2KWMZB9DFAUWRK0HXg3ozACcV KiOoYgiwY9dHQ== X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ralph Campbell , nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Jason Gunthorpe , amd-gfx@lists.freedesktop.org, Andrew Morton , Christoph Hellwig Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Allow hmm_range_fault() to return success (0) when the range has no access (!(vma->vm_flags & VM_READ)). The range->pfns[] array will be filled with range->values[HMM_PFN_NONE] in this case. This allows the caller to get a snapshot of a range without having to lookup the vma before calling hmm_range_fault(). If the call to hmm_range_fault() is not a snapshot, the caller can still check that pfns have the desired access permissions. Signed-off-by: Ralph Campbell Cc: "Jérôme Glisse" Cc: Jason Gunthorpe Cc: Christoph Hellwig --- mm/hmm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/hmm.c b/mm/hmm.c index 7217912bef13..16c834e5d1c0 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -795,7 +795,9 @@ static int hmm_vma_walk_test(unsigned long start, */ if (!(vma->vm_flags & VM_READ)) { (void) hmm_pfns_fill(start, end, range, HMM_PFN_NONE); - return -EPERM; + + /* Skip this vma and continue processing the next vma. */ + return 1; } return 0;