From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 84C4156852D; Thu, 17 Sep 2026 16:32:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789662762; cv=none; b=GglLIQcKlf0zTzOJFQNr+yAU+TwiAYo+AVo4i7Dxq1KqtN8OtVshm9+IkTYRVn90AzHZmsbamrHCs/ISmHjOEMjNOpTZUr27ron015nGXMdsDzncmJ3JhO9Jx1edTl6heoqKAsG5WQ58owlf4P+41zrZVET8jaKO1lHsS7GzdXM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789662762; c=relaxed/simple; bh=In9WHX8b1sLbbe6jUcP+2i7LCzJ4p//dj4w0OtHuz9I=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Fo73xxY1dLeONx1yKIwrpzF/TuHu7JnK8CN9fUkewn+aOfm47hjx01/Don9x7NT33ugJNW0EHtOGVEE437seTMksNNiz3wvZ7qLHhI6bf4fYfIM/T3G9JNwMuI69TfowoZM91CBpAUSSHgqgU6+6WyvKcy+r3UqR7xK4mCCHBKg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FdLw98tn; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FdLw98tn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4CC201F00899; Thu, 17 Sep 2026 16:32:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789662760; bh=R1TTFxJqK2JOmLB4wxg0hlSgvzQnwmSO7NGWVXFT9S4=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=FdLw98tnnAoDtWH8kD0dPvk66NNqKS785LfS0XG2ecgpcUicXfTn4HGu3RCwa2PmW tPhI1GvWWiu11djXSGAre8RjZgwuCIibHgzbSC6aSdaemxpRXKiorH/HqCo2sgumn/ fvbto+ZFnQL6qSXhc1Xj+kLs10DOhc3iBSRgQQoSDG9t2MRbNJb8kV0gDl2WYT/Je/ PyeOf5EwRvMKqcXppj1Nc7NIYrxSxhLgXwXtr9nlTLPjIEzaIs834ljJ91EuHrQrKT /3V4+AavOF/q2rkxgpcN9Y0daI6siTUv8WWfukz/a4HpzwIh6nvg4pHK3HEBHqDDmX OLAFkk6l2yBHw== From: "Lorenzo Stoakes (ARM)" Date: Thu, 17 Sep 2026 17:22:28 +0100 Subject: [PATCH v3 19/40] fbdev: defio: assert FBINFO_VIRTFB, drop VM_IO, add VM_MIXEDMAP Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-19-4583d8a23bca@kernel.org> References: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> In-Reply-To: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> To: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , David Hildenbrand , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonathan Corbet , Greg Kroah-Hartman , Dennis Dalessandro , Jason Gunthorpe , Leon Romanovsky , Paul Moore , Stephen Smalley , Jaroslav Kysela , Takashi Iwai , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Doug Gilbert , "James E.J. Bottomley" , "Martin K. Petersen" , Jaya Kumar , Simona Vetter , Helge Deller , Sebastian Reichel , John Hubbard , Peter Xu , Masami Hiramatsu , Oleg Nesterov , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Rik van Riel , Harry Yoo , Juri Lelli , Vincent Guittot , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Arnd Bergmann , Muchun Song , Oscar Salvador , "Matthew Wilcox (Oracle)" , Jan Kara , Marc Zyngier , Oliver Upton , Catalin Marinas , Madhavan Srinivasan , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , "David S. Miller" , Andreas Larsson , Alexander Viro , Christian Brauner , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Youngjun Park , Johannes Weiner , Qi Zheng , Shakeel Butt , Axel Rasmussen , Yuanchu Xie , Wei Xu , Chengming Zhou , Michal Hocko , Miklos Szeredi , Xu Xin Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-usb@vger.kernel.org, linux-rdma@vger.kernel.org, selinux@vger.kernel.org, linux-sound@vger.kernel.org, bpf@vger.kernel.org, linux-scsi@vger.kernel.org, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, fuse-devel@lists.linux.dev, "Lorenzo Stoakes (ARM)" X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=2362; i=ljs@kernel.org; h=from:subject:message-id; bh=In9WHX8b1sLbbe6jUcP+2i7LCzJ4p//dj4w0OtHuz9I=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLLWCB+8bOi9UPLIo/LJk2JWhM3+b3BdgtnAyfJrpf4ET s3Sm/x3O0pZGMS4GGTFFFmefxHfHyQSNq/zgr8bzBxWJpAhDFycAjCRD0cYGRrX9Htz//Woqtj5 yGpTVNPsHHWljs3FZyeckZj57lRJoCTD/1qtjbYPt3hX96zbuyf64ve193k5H5nVanZnM7eYLUs W4AYA X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 Currently all drivers which use defio allocate system memory. All of them also set FBINFO_VIRTFB, other than ssd1307fb, however this driver allocates system RAM, so simply failed to set this flag when it ought to. This patch sets FBINFO_VIRTFB on ssd1307fb probe, then drops setting VM_IO in fb_deferred_io_mmap() and instead requires FBINFO_VIRTFB to be set, erroring out with a kernel warning if not. The logic requires a page from the driver and since commit 1ecbc7dd2902 ("fbdev/deferred-io: Always call get_page() for framebuffer pages") has always required it to be refcounted, so this was implicitly already the case. Finally this patch sets VM_MIXEDMAP, as the logic is mapping kernel-allocated memory so this is appropriate. Reviewed-by: Thomas Zimmermann Signed-off-by: Lorenzo Stoakes (ARM) --- drivers/video/fbdev/core/fb_defio.c | 6 +++--- drivers/video/fbdev/ssd1307fb.c | 2 ++ 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c index fd00b86e1ae6..fb359ecc3966 100644 --- a/drivers/video/fbdev/core/fb_defio.c +++ b/drivers/video/fbdev/core/fb_defio.c @@ -366,13 +366,13 @@ int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma) { vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); + if (WARN_ON_ONCE(!(info->flags & FBINFO_VIRTFB))) + return -EINVAL; if (!try_module_get(THIS_MODULE)) return -EINVAL; vma->vm_ops = &fb_deferred_io_vm_ops; - vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP); - if (!(info->flags & FBINFO_VIRTFB)) - vm_flags_set(vma, VM_IO); + vm_flags_set(vma, VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP); vma->vm_private_data = info->fbdefio_state; fb_deferred_io_state_get(info->fbdefio_state); /* released in vma->vm_ops->close() */ diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index c4fdecafd856..958514a35433 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -763,6 +763,8 @@ static int ssd1307fb_probe(struct i2c_client *client) info->fix.smem_start = __pa(vmem); info->fix.smem_len = vmem_size; + info->flags = FBINFO_VIRTFB; + fb_deferred_io_init(info); i2c_set_clientdata(client, info); -- 2.55.0