Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934772AbbEOT4N (ORCPT ); Fri, 15 May 2015 15:56:13 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:48327 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934313AbbEOT4F (ORCPT ); Fri, 15 May 2015 15:56:05 -0400 Date: Fri, 15 May 2015 15:55:51 -0400 From: Konrad Rzeszutek Wilk To: Alexandre Courbot Cc: Thierry Reding , Thomas Hellstrom , Arnd Bergmann , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, gnurou@gmail.com Subject: Re: [PATCH] drm/ttm: dma: Don't crash on memory in the vmalloc range Message-ID: <20150515195551.GE23819@l.oracle.com> References: <1431673794-16169-1-git-send-email-acourbot@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1431673794-16169-1-git-send-email-acourbot@nvidia.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1873 Lines: 52 On Fri, May 15, 2015 at 04:09:54PM +0900, Alexandre Courbot wrote: > dma_alloc_coherent() can return memory in the vmalloc range. > virt_to_page() cannot handle such addresses and crashes. This > patch detects such cases and obtains the struct page * using > vmalloc_to_page() instead. > > Signed-off-by: Alexandre Courbot > --- > This patch is a follow-up of the following discussion: > > https://www.marc.info/?l=dri-devel&m=141579595431254&w=3 > > It works for me on both 32-bit and 64-bit Tegra, so I am not convinced > that Thierry's initial change from virt_to_page() to phys_to_page() is > still required - Thierry, can you confirm whether your patch is still > relevant after this one? > > drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c > index 01e1d27eb078..3077f1554099 100644 > --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c > +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c > @@ -342,9 +342,12 @@ static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool) > d_page->vaddr = dma_alloc_coherent(pool->dev, pool->size, > &d_page->dma, > pool->gfp_flags); > - if (d_page->vaddr) > - d_page->p = virt_to_page(d_page->vaddr); > - else { > + if (d_page->vaddr) { > + if (is_vmalloc_addr(d_page->vaddr)) > + d_page->p = vmalloc_to_page(d_page->vaddr); > + else > + d_page->p = virt_to_page(d_page->vaddr); > + } else { Looks OK to me. > kfree(d_page); > d_page = NULL; > } > -- > 2.4.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/