From patchwork Sat Jun 26 12:57:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= X-Patchwork-Id: 12346441 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E51BC49EA7 for ; Sat, 26 Jun 2021 12:57:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E14B361C30 for ; Sat, 26 Jun 2021 12:57:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229518AbhFZNAB (ORCPT ); Sat, 26 Jun 2021 09:00:01 -0400 Received: from mail-ej1-f46.google.com ([209.85.218.46]:38851 "EHLO mail-ej1-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229556AbhFZNAB (ORCPT ); Sat, 26 Jun 2021 09:00:01 -0400 Received: by mail-ej1-f46.google.com with SMTP id hq39so19806894ejc.5 for ; Sat, 26 Jun 2021 05:57:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=xsjHsDPdWs8TcY1m0N+2WCt8b2rnx8PsMgsqmc5Y+4A=; b=hapfOcYhLWlWFqFVxyZU12tEpoVklXWr+/NgYUNuNXeMHY6muQ/o7aKVHDNNi6fobS /OnlIJzAHgwWzdSVx7MBi5oJ4MuS1vw5tjcrnS5gRME5CjbPUMgepawnDc2W4f0yMab/ rpySSSZ7HgP4qhokJ2tY74j8ezAFOiwW3NzhVAuQtZTltz4LBqgBkArRq/Biu7S9OTuF WWT0Ukz6keSpE2lkVkvB7rS0EVav/ztkmgFsjwzI592z8qvfRqekOD4BqvQtJA+Pd0eD GPtxAdkoo9dWexIbEKLAAblg9q33rm/dYYBxEYJ/3cG8wOfp0DHHj8S/WX148PvLnNbZ fg3Q== X-Gm-Message-State: AOAM532eZ3lM7466tNcWr7o9yFemOQQnzQg0Xt1IKP/PUH0b6f6sl5x/ Jr0tmm/F7vaoSRYgaNm64pA= X-Google-Smtp-Source: ABdhPJzxEoD+LvlwKNwPPHNake4JrDGHfuTkH5IhghUt/R010KPmYuzVRMCHhxvS5TBCq9zVmB0NNQ== X-Received: by 2002:a17:906:9bd5:: with SMTP id de21mr15741797ejc.554.1624712258438; Sat, 26 Jun 2021 05:57:38 -0700 (PDT) Received: from workstation.lan ([95.155.85.46]) by smtp.gmail.com with ESMTPSA id e7sm3755748ejm.93.2021.06.26.05.57.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 26 Jun 2021 05:57:38 -0700 (PDT) From: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= To: Bjorn Helgaas Cc: Dan Williams , Greg Kroah-Hartman , Daniel Vetter , Kees Cook , =?utf-8?q?Pali_Roh=C3=A1r?= , "Oliver O'Halloran" , linux-pci@vger.kernel.org Subject: [PATCH v2 1/3] sysfs: Invoke iomem_get_mapping() from the sysfs open callback Date: Sat, 26 Jun 2021 12:57:33 +0000 Message-Id: <20210626125735.2868256-2-kw@linux.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210626125735.2868256-1-kw@linux.com> References: <20210626125735.2868256-1-kw@linux.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Defer invocation of the iomem_get_mapping() to the sysfs open callback so that it can be executed as needed when the binary sysfs object has been accessed. To do that, convert the "mapping" member of the struct bin_attribute from a pointer to the struct address_space into a function pointer with a signature that requires the same return type, and then updates the sysfs_kf_bin_open() to invoke provided function should the function pointer be valid. Thus, this change removes the need for the fs_initcalls to complete before any other sub-system that uses the iomem_get_mapping() would be able to invoke it safely without leading to a failure and an Oops related to an invalid iomem_get_mapping() access. Suggested-by: Dan Williams Signed-off-by: Dan Williams Signed-off-by: Krzysztof Wilczyński Reported-by: kernel test robot --- fs/sysfs/file.c | 2 +- include/linux/sysfs.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 9aefa7779b29..a3ee4c32a264 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -175,7 +175,7 @@ static int sysfs_kf_bin_open(struct kernfs_open_file *of) struct bin_attribute *battr = of->kn->priv; if (battr->mapping) - of->file->f_mapping = battr->mapping; + of->file->f_mapping = battr->mapping(); return 0; } diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index d76a1ddf83a3..fbb7c7df545c 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -170,7 +170,7 @@ struct bin_attribute { struct attribute attr; size_t size; void *private; - struct address_space *mapping; + struct address_space *(*mapping)(void); ssize_t (*read)(struct file *, struct kobject *, struct bin_attribute *, char *, loff_t, size_t); ssize_t (*write)(struct file *, struct kobject *, struct bin_attribute *,