From patchwork Mon Jul 1 06:20:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11025011 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 31B7713B1 for ; Mon, 1 Jul 2019 06:21:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3099128329 for ; Mon, 1 Jul 2019 06:21:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 24B9D284DA; Mon, 1 Jul 2019 06:21:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D6A2428329 for ; Mon, 1 Jul 2019 06:21:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727763AbfGAGVO (ORCPT ); Mon, 1 Jul 2019 02:21:14 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:48668 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727773AbfGAGVO (ORCPT ); Mon, 1 Jul 2019 02:21:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=pfzb7DKQGxSim4j5P5NViAehCYDnD7twhlehxZF4/mk=; b=Sh+xg97CAaxfCofmcqXvvWAphg /FC2T86IXntWnlzo7VNQ0a7nvzkSU5M8Vor1yTinwL8XHWySWdAmf559BGxhLygWpZkXa+jWcNQpF yiqysTo4IQb6Xpt1GUM99QV4WcYAL16tbM/uA/Iri95ouR7gdrojQ0Q1FFO88taxm3tHE0W2P75Ls uFALgpav78FJe/L2HvoUQuW9Nx75lFKVz+WQqk7Svyo2Nz6faU7+QmTVPfGCiVaW1HVgnmdn0SnRa bWnACDf6hys4JLjnsuvv+pNy9oG68GRh5KBdYs5IrjoRydXBE/posTx59K1lsO1UsoEGdwy2Of8G0 zfk6CmHg==; Received: from [46.140.178.35] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hhpgb-0003W2-Ks; Mon, 01 Jul 2019 06:21:09 +0000 From: Christoph Hellwig To: Dan Williams , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Jason Gunthorpe , Ben Skeggs Cc: Ira Weiny , linux-mm@kvack.org, nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-nvdimm@lists.01.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 21/22] nouveau: unlock mmap_sem on all errors from nouveau_range_fault Date: Mon, 1 Jul 2019 08:20:19 +0200 Message-Id: <20190701062020.19239-22-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190701062020.19239-1-hch@lst.de> References: <20190701062020.19239-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently nouveau_svm_fault expects nouveau_range_fault to never unlock mmap_sem, but the latter unlocks it for a random selection of error codes. Fix this up by always unlocking mmap_sem for non-zero return values in nouveau_range_fault, and only unlocking it in the caller for successful returns. Signed-off-by: Christoph Hellwig --- drivers/gpu/drm/nouveau/nouveau_svm.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c index e831f4184a17..c0cf7aeaefb3 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.c +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c @@ -500,8 +500,10 @@ nouveau_range_fault(struct hmm_mirror *mirror, struct hmm_range *range, ret = hmm_range_register(range, mirror, range->start, range->end, PAGE_SHIFT); - if (ret) + if (ret) { + up_read(&range->vma->vm_mm->mmap_sem); return (int)ret; + } if (!hmm_range_wait_until_valid(range, NOUVEAU_RANGE_FAULT_TIMEOUT)) { /* @@ -515,15 +517,14 @@ nouveau_range_fault(struct hmm_mirror *mirror, struct hmm_range *range, ret = hmm_range_fault(range, block); if (ret <= 0) { - if (ret == -EBUSY || !ret) { - /* Same as above, drop mmap_sem to match old API. */ - up_read(&range->vma->vm_mm->mmap_sem); - ret = -EBUSY; - } else if (ret == -EAGAIN) + if (ret == 0) ret = -EBUSY; + if (ret != -EAGAIN) + up_read(&range->vma->vm_mm->mmap_sem); hmm_range_unregister(range); return ret; } + return 0; } @@ -718,8 +719,8 @@ nouveau_svm_fault(struct nvif_notify *notify) NULL); svmm->vmm->vmm.object.client->super = false; mutex_unlock(&svmm->mutex); + up_read(&svmm->mm->mmap_sem); } - up_read(&svmm->mm->mmap_sem); /* Cancel any faults in the window whose pages didn't manage * to keep their valid bit, or stay writeable when required.