From patchwork Fri Apr 16 20:58:42 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: 12208799 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,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 8295BC433ED for ; Fri, 16 Apr 2021 20:59:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A1C8613CE for ; Fri, 16 Apr 2021 20:59:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343817AbhDPU7b (ORCPT ); Fri, 16 Apr 2021 16:59:31 -0400 Received: from mail-ed1-f54.google.com ([209.85.208.54]:40814 "EHLO mail-ed1-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235963AbhDPU73 (ORCPT ); Fri, 16 Apr 2021 16:59:29 -0400 Received: by mail-ed1-f54.google.com with SMTP id o20so7548371edc.7 for ; Fri, 16 Apr 2021 13:59:04 -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=JeUgz7b7rXLxynuNSGprjbs9WcXU7kskGSfcqquriAo=; b=rW8f28aLJSUFhI+S10vhOWIbEnH3nEsI6CporQAeTj6XH24orW0al/xDw9ZaVU9Ria wvkUrix2bt5+K3OIWy22NMbXKHb/JMvHtT1fdNa7J5cPJaRXR0TjK0+2lZ2KiTbXGLJU 1TjvxRqLuBmmWZ7UCjTmF+J9pZ+UQzNgeRwVOkEkbDpwkiUkWGlmXj5PsYxHY37+3MTO lMZAL188gobWjDTlfz2wFjKlEriJu/HBBzkbUAK5xQjwl/jA+0fV6/wnR7FyLYWL7Zin BEJjW5FB5ZAdHN1S5MMJxi75RBY97HUmFnYzIM+H9j8qRFUOl30xUq/t9z9Y7epfsoc2 BG2Q== X-Gm-Message-State: AOAM532z5VXAN95MqTDlfGQhO1UQPL0c/9MLrtkHIa6JRNJLaaGMBwqN 3OUsLT8DJz381q9mhtthVKE= X-Google-Smtp-Source: ABdhPJwVOkc6xSk37T2eHXQV6vW3+g077Om5a1OPNiB2/FC1ntKWNRjN+pE8ReGeKIrjo0EMw9X4/w== X-Received: by 2002:aa7:c1c8:: with SMTP id d8mr12245446edp.236.1618606743761; Fri, 16 Apr 2021 13:59:03 -0700 (PDT) Received: from workstation.lan ([95.155.85.46]) by smtp.gmail.com with ESMTPSA id n11sm5103864ejg.43.2021.04.16.13.59.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 16 Apr 2021 13:59:03 -0700 (PDT) From: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= To: Bjorn Helgaas Cc: =?utf-8?q?Pali_Roh=C3=A1r?= , "Oliver O'Halloran" , Greg Kroah-Hartman , Daniel Vetter , Joe Perches , Dan Williams , Mauro Carvalho Chehab , David Sterba , linux-pci@vger.kernel.org Subject: [PATCH 06/20] sysfs: Introduce BIN_ATTR_ADMIN_RO and BIN_ATTR_ADMIN_RW Date: Fri, 16 Apr 2021 20:58:42 +0000 Message-Id: <20210416205856.3234481-7-kw@linux.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210416205856.3234481-1-kw@linux.com> References: <20210416205856.3234481-1-kw@linux.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org A very common use case is to limit read and/or write access to certain sysfs objects to only root with the expectation that the CAP_SYS_ADMIN capability is needed to access sensitive data exposed through such sysfs objects. The existing macros such as BIN_ATTR_RO and BIN_ATTR_RW are sadly inadequate given the specific need to limit access only to the root user, as they offer permissions that are too open e.g., 0444 and 0644, thus a lot of users of binary attributes with this specific use case, for example, the PCI "config", "rom" and "vps" sysfs objects, would opt to use the BIN_ATTR macro directly specifying 0400 or 0600 as needed. Add a new set of macros with an explicit "ADMIN" identifier catering to this specific use case that also follows the semantic of other existing macros such as e.g., BIN_ATTR_RO, BIN_ATTR_RW, BIN_ATTR_WO, etc. No functional change intended. Related: commit 60d360acddc5 ("driver-core: Introduce DEVICE_ATTR_ADMIN_{RO,RW}") Signed-off-by: Krzysztof Wilczyński --- include/linux/sysfs.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index d76a1ddf83a3..9f423dfa8494 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -205,6 +205,13 @@ struct bin_attribute { .size = _size, \ } +#define __BIN_ATTR_RO_MODE(_name, _mode, _size) { \ + .attr = { .name = __stringify(_name), \ + .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \ + .read = _name##_read, \ + .size = _size, \ +} + #define __BIN_ATTR_WO(_name, _size) { \ .attr = { .name = __stringify(_name), .mode = 0200 }, \ .write = _name##_write, \ @@ -214,6 +221,14 @@ struct bin_attribute { #define __BIN_ATTR_RW(_name, _size) \ __BIN_ATTR(_name, 0644, _name##_read, _name##_write, _size) +#define __BIN_ATTR_RW_MODE(_name, _mode, _size) { \ + .attr = { .name = __stringify(_name), \ + .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \ + .read = _name##_read, \ + .write = _name##_write, \ + .size = _size, \ +} + #define __BIN_ATTR_NULL __ATTR_NULL #define BIN_ATTR(_name, _mode, _read, _write, _size) \ @@ -223,12 +238,20 @@ struct bin_attribute bin_attr_##_name = __BIN_ATTR(_name, _mode, _read, \ #define BIN_ATTR_RO(_name, _size) \ struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO(_name, _size) +#define BIN_ATTR_ADMIN_RO(_name, _size) \ +struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO_MODE(_name, 0400, \ + _size) + #define BIN_ATTR_WO(_name, _size) \ struct bin_attribute bin_attr_##_name = __BIN_ATTR_WO(_name, _size) #define BIN_ATTR_RW(_name, _size) \ struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size) +#define BIN_ATTR_ADMIN_RW(_name, _size) \ +struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW_MODE(_name, 0600, \ + _size) + struct sysfs_ops { ssize_t (*show)(struct kobject *, struct attribute *, char *); ssize_t (*store)(struct kobject *, struct attribute *, const char *, size_t);