From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 17A97C531C9 for ; Sat, 25 Jul 2026 21:06:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc: To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=aPa/LsrTp3hYJdTLzZYHVqwcc+ik3K0gwTpILC+a88c=; b=MvUNDPfj9BA1UltIf/5H+CjsTD t/02uSfxd2BxxPAM6vdltgq9D1u83DygiluWk3PnlSM+wkISFYAD0pQQUDt1ZyT9svLiNXTqmWH5o 5VxqGgdwovxPWeNSGMtG/e4yFv6UtpdEnZPt4gvATbp+EuPtso0hf+aJF4LLI3F6cyFi4sUYChZ4+ 3PE6KSTYMSp7A0PAm4bkEcwcVo7BbC6/optvgoXJxZVvYfyjgIShAlmLuxAplOQ23xmhA8mvHn3UT s4GI/6MfaCVATiKsdpvZDIgO1sJEYnvhzqI9Bo8T91hrJDVDA9dUCnacvzYay5RwqCU0rH8QGxWUV b6gA6gXA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wnjZN-00000000iJn-0rTS; Sat, 25 Jul 2026 21:06:05 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wnjZL-00000000iJH-3juv for kexec@lists.infradead.org; Sat, 25 Jul 2026 21:06:04 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id EA61960A98; Sat, 25 Jul 2026 21:06:02 +0000 (UTC) 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> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org 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