Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934502AbbEOMDb (ORCPT ); Fri, 15 May 2015 08:03:31 -0400 Received: from mail-ie0-f170.google.com ([209.85.223.170]:34571 "EHLO mail-ie0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933981AbbEOMD3 (ORCPT ); Fri, 15 May 2015 08:03:29 -0400 MIME-Version: 1.0 In-Reply-To: <1431673794-16169-1-git-send-email-acourbot@nvidia.com> References: <1431673794-16169-1-git-send-email-acourbot@nvidia.com> Date: Fri, 15 May 2015 20:03:29 +0800 Message-ID: Subject: Re: [PATCH] drm/ttm: dma: Don't crash on memory in the vmalloc range From: yalin wang To: Alexandre Courbot Cc: Thierry Reding , Konrad Rzeszutek Wilk , Thomas Hellstrom , Arnd Bergmann , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, gnurou@gmail.com, will.deacon@arm.com, linux-arm-kernel@lists.infradead.org, Neil.Gao@sonymobile.com Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2969 Lines: 75 2015-05-15 15:09 GMT+08:00 Alexandre Courbot : > 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 { > 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/ for safe , i think we can add this patch: diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index f800d45..3463f4f 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -77,7 +77,8 @@ * private definitions which should NOT be used outside memory.h * files. Use virt_to_phys/phys_to_virt/__pa/__va instead. */ -#define __virt_to_phys(x) (((phys_addr_t)(x) - PAGE_OFFSET + PHYS_OFFSET)) +#define __virt_to_phys(x) ({BUG_ON(x < PAGE_OFFSET);\ + (phys_addr_t)(x) - PAGE_OFFSET + PHYS_OFFSET;}) #define __phys_to_virt(x) ((unsigned long)((x) - PHYS_OFFSET + PAGE_OFFSET)) /* BRs Yalin -- 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/