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 EB021327BFB; Sat, 25 Jul 2026 21:06:02 +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=1785013564; cv=none; b=UqRTtDSWV9zajT7w0H1yIEdfRz2N7NYjrzJuASy0e5HwHfxQ/e0i8ohEMxmRC3Yzw5YOVXQwE44t6AmpJmoMdl+FyWthTwuvYuCL6pd/x+uDw69mwSFDFkc1IBrxw1Ny/6Q0VEn1eWh5DyHOG+dPkKEXPj6lYQ2xnHbjeSQoK8E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785013564; c=relaxed/simple; bh=B5Pq9++XsW99sXcMbfjY10sI4MpaEJaAIafiFz1a9Hg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=YkXxwy/g08WX8MZB5RLIfTJxHIbMkUz7oFHtRDB2kNn7bQOlM9bu0Et9EkCRMkSzPRMireeqXl0BA9lqMxxvqv7sCj+sbDEGfGLOtPqKk2GrNaOkLwM/OOjuO8XtvBvJQy+nFDbKF6adOR7JdDZdgyLLMBhdNGOW+ByqBXtFc08= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Qx53A1oD; 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="Qx53A1oD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD7C41F01558; Sat, 25 Jul 2026 21:05:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785013562; bh=aPa/LsrTp3hYJdTLzZYHVqwcc+ik3K0gwTpILC+a88c=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Qx53A1oDvALciaFuFZCSSzhSlAz/InNoUWnSh/Gm5zNnNDFwrP2ubUYudxorFmIZ8 7zEIFtByOjtavUSHsMvApD7vD4GBbbBZ01esE+wg5sPWNTKs/+gt2cyZMdOV+UfNyB GhqmCpoYIW4VHpQkIkngfd7iRMJAUjiV4C9aM74c3W8vOj+ntcwdGTREkVPCVA6Avr qHdaGVv0kn9+MfiHmWQe8iz/+hbFJUASZfScyxqob2Rx+S5IFMVrQfSrTNtueszMAu vKdnfxeTOPtQVYJsZOHmXU20gLd2UcFmXX2j+Jf0km+iLaw1Y9SMUcfySmRzl1/sU7 qSLDsH6/40CsA== From: =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= To: Andrew Morton , David Hildenbrand , Greg Kroah-Hartman , Tejun Heo , Bjorn Helgaas Cc: Bjorn Helgaas , Manivannan Sadhasivam , Lorenzo Pieralisi , "Liam R . Howlett" , Baoquan He , Pratyush Yadav , Pasha Tatashin , Jaroslav Kysela , Takashi Iwai , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Simona Vetter , Suren Baghdasaryan , Vlastimil Babka , Dave Young , linux-mm@kvack.org, linux-pci@vger.kernel.org, linux-sound@vger.kernel.org, kexec@lists.infradead.org, driver-core@lists.linux.dev Subject: [PATCH v2 2/3] kernfs: Unmap mmaps of removed files via file->f_mapping Date: Sat, 25 Jul 2026 21:05:48 +0000 Message-ID: <20260725210549.3716546-3-kwilczynski@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260725210549.3716546-1-kwilczynski@kernel.org> References: <20260725210549.3716546-1-kwilczynski@kernel.org> Precedence: bulk X-Mailing-List: driver-core@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, kernfs_drain_open_files() unmaps the mapping of the sysfs inode, file_inode(of->file)->i_mapping, when a node with mmapped open files is removed. Since commit 636b21b50152 ("PCI: Revoke mappings like devmem"), PCI resource and legacy sysfs files swap their f_mapping to iomem_get_mapping() at open time, so their VMAs are attached to the shared iomem address space, which the drain never unmaps. As a result, userspace mappings of PCI BARs survive device removal and BAR resize, keeping stale PTEs into physical address space that the kernel may have reassigned since. Thus, use unmap_mapping_file() for every open file, so that only the VMAs of the node being removed are zapped, while unrelated mappings are left intact. The same helper also covers files without a swapped f_mapping, and the driver-claim revocation through revoke_iomem() is unaffected, as those VMAs remain on the shared address space. This restores the behaviour these files had before the f_mapping swap was introduced. A read through a stale mapping after removal now raises SIGBUS instead of returning stale data. Fixes: 636b21b50152 ("PCI: Revoke mappings like devmem") Signed-off-by: Krzysztof Wilczyński --- fs/kernfs/file.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 8e0e90c93372..eb04439e9c3e 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -815,10 +815,8 @@ void kernfs_drain_open_files(struct kernfs_node *kn) } list_for_each_entry(of, &on->files, list) { - struct inode *inode = file_inode(of->file); - if (of->mmapped) { - unmap_mapping_range(inode->i_mapping, 0, 0, 1); + unmap_mapping_file(of->file); of->mmapped = false; on->nr_mmapped--; } -- 2.55.0