From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-f197.google.com (mail-lj1-f197.google.com [209.85.208.197]) by kanga.kvack.org (Postfix) with ESMTP id 770448E0004 for ; Fri, 7 Dec 2018 15:27:03 -0500 (EST) Received: by mail-lj1-f197.google.com with SMTP id l12-v6so1363550ljb.11 for ; Fri, 07 Dec 2018 12:27:03 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id a13-v6sor3124253ljj.25.2018.12.07.12.27.01 for (Google Transport Security); Fri, 07 Dec 2018 12:27:01 -0800 (PST) MIME-Version: 1.0 References: <20181206184227.GA28656@jordon-HP-15-Notebook-PC> In-Reply-To: From: Souptick Joarder Date: Sat, 8 Dec 2018 02:00:36 +0530 Message-ID: Subject: Re: [PATCH v3 4/9] drm/rockchip/rockchip_drm_gem.c: Convert to use vm_insert_range Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: robin.murphy@arm.com Cc: Andrew Morton , Matthew Wilcox , Michal Hocko , hjc@rock-chips.com, Heiko Stuebner , airlied@linux.ie, Linux-MM , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org On Fri, Dec 7, 2018 at 8:20 PM Robin Murphy wrote: > > On 06/12/2018 18:42, Souptick Joarder wrote: > > Convert to use vm_insert_range() to map range of kernel > > memory to user vma. > > > > Signed-off-by: Souptick Joarder > > Tested-by: Heiko Stuebner > > Acked-by: Heiko Stuebner > > --- > > drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 20 ++------------------ > > 1 file changed, 2 insertions(+), 18 deletions(-) > > > > diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c > > index a8db758..2cb83bb 100644 > > --- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c > > +++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c > > @@ -221,26 +221,10 @@ static int rockchip_drm_gem_object_mmap_iommu(struct drm_gem_object *obj, > > struct vm_area_struct *vma) > > { > > struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj); > > - unsigned int i, count = obj->size >> PAGE_SHIFT; > > unsigned long user_count = vma_pages(vma); > > - unsigned long uaddr = vma->vm_start; > > - unsigned long offset = vma->vm_pgoff; > > - unsigned long end = user_count + offset; > > - int ret; > > - > > - if (user_count == 0) > > - return -ENXIO; > > - if (end > count) > > - return -ENXIO; > > > > - for (i = offset; i < end; i++) { > > - ret = vm_insert_page(vma, uaddr, rk_obj->pages[i]); > > - if (ret) > > - return ret; > > - uaddr += PAGE_SIZE; > > - } > > - > > - return 0; > > + return vm_insert_range(vma, vma->vm_start, rk_obj->pages, > > + user_count); > > We're losing vm_pgoff handling here, which given the implication in > 57de50af162b, may well be a regression for at least some combination of > GPU and userspace driver (I assume that commit was in the context of > some version of the Arm Mali driver, possibly on RK3288). In commit 57de50af162b, vma->vm_pgoff = 0 for GEM mmap handler context and removing it from common path which means if call stack looks like rockchip_gem_mmap_buf() -> rockchip_drm_gem_object_mmap() -> rockchip_drm_gem_object_mmap_iommu(), then we might have a non zero vma->vm_pgoff context which is not handled. This is the problem you are pointing ? right ?