From patchwork Thu Apr 2 15:30:15 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lucas Stach X-Patchwork-Id: 6149731 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 5A90CBF4A6 for ; Thu, 2 Apr 2015 15:32:10 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 71C66203AC for ; Thu, 2 Apr 2015 15:32:09 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 8C487203AB for ; Thu, 2 Apr 2015 15:32:08 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2E5BA6EADC; Thu, 2 Apr 2015 08:31:09 -0700 (PDT) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [92.198.50.35]) by gabe.freedesktop.org (Postfix) with ESMTP id 4903A6EA65 for ; Thu, 2 Apr 2015 08:31:00 -0700 (PDT) Received: from dude.hi.4.pengutronix.de ([10.1.0.7] helo=dude.pengutronix.de.) by metis.ext.pengutronix.de with esmtp (Exim 4.72) (envelope-from ) id 1Ydh59-0005OD-Ju; Thu, 02 Apr 2015 17:30:59 +0200 From: Lucas Stach To: dri-devel@lists.freedesktop.org Subject: [PATCH RFC 073/111] staging: etnaviv: iommu: add a poisoned bad page Date: Thu, 2 Apr 2015 17:30:15 +0200 Message-Id: <1427988653-754-74-git-send-email-l.stach@pengutronix.de> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1427988653-754-1-git-send-email-l.stach@pengutronix.de> References: <1427988653-754-1-git-send-email-l.stach@pengutronix.de> X-SA-Exim-Connect-IP: 10.1.0.7 X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: dri-devel@lists.freedesktop.org Cc: Russell King , kernel@pengutronix.de X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Russell King Add a poisoned bad page to map unused MMU entries to. This gives us a certain amount of protection against bad command streams causing us to hit regions of memory we really shouldn't be touching. Signed-off-by: Russell King --- drivers/staging/etnaviv/etnaviv_iommu.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/drivers/staging/etnaviv/etnaviv_iommu.c b/drivers/staging/etnaviv/etnaviv_iommu.c index 327ca703bc65..71f94dac650b 100644 --- a/drivers/staging/etnaviv/etnaviv_iommu.c +++ b/drivers/staging/etnaviv/etnaviv_iommu.c @@ -36,6 +36,8 @@ struct etnaviv_iommu_domain_pgtable { }; struct etnaviv_iommu_domain { + void *bad_page_cpu; + dma_addr_t bad_page_dma; struct etnaviv_iommu_domain_pgtable pgtable; spinlock_t map_lock; }; @@ -80,18 +82,38 @@ static void pgtable_write(struct etnaviv_iommu_domain_pgtable *pgtable, static int etnaviv_iommu_domain_init(struct iommu_domain *domain) { struct etnaviv_iommu_domain *etnaviv_domain; - int ret; + uint32_t iova, *p; + int ret, i; etnaviv_domain = kmalloc(sizeof(*etnaviv_domain), GFP_KERNEL); if (!etnaviv_domain) return -ENOMEM; + etnaviv_domain->bad_page_cpu = dma_alloc_coherent(NULL, SZ_4K, + &etnaviv_domain->bad_page_dma, + GFP_KERNEL); + if (!etnaviv_domain->bad_page_cpu) { + kfree(etnaviv_domain); + return -ENOMEM; + } + p = etnaviv_domain->bad_page_cpu; + for (i = 0; i < SZ_4K / 4; i++) + *p++ = 0xdead55aa; + ret = pgtable_alloc(&etnaviv_domain->pgtable, PT_SIZE); if (ret < 0) { + dma_free_coherent(NULL, SZ_4K, etnaviv_domain->bad_page_cpu, + etnaviv_domain->bad_page_dma); kfree(etnaviv_domain); return ret; } + for (iova = domain->geometry.aperture_start; + iova < domain->geometry.aperture_end; iova += SZ_4K) { + pgtable_write(&etnaviv_domain->pgtable, iova, + etnaviv_domain->bad_page_dma); + } + spin_lock_init(&etnaviv_domain->map_lock); domain->priv = etnaviv_domain; return 0; @@ -103,6 +125,8 @@ static void etnaviv_iommu_domain_destroy(struct iommu_domain *domain) pgtable_free(&etnaviv_domain->pgtable, PT_SIZE); + dma_free_coherent(NULL, SZ_4K, etnaviv_domain->bad_page_cpu, + etnaviv_domain->bad_page_dma); kfree(etnaviv_domain); domain->priv = NULL; } @@ -131,7 +155,8 @@ static size_t etnaviv_iommu_unmap(struct iommu_domain *domain, return -EINVAL; spin_lock(&etnaviv_domain->map_lock); - pgtable_write(&etnaviv_domain->pgtable, iova, ~0); + pgtable_write(&etnaviv_domain->pgtable, iova, + etnaviv_domain->bad_page_dma); spin_unlock(&etnaviv_domain->map_lock); return SZ_4K;