From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751618AbdJGGyP (ORCPT ); Sat, 7 Oct 2017 02:54:15 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:59467 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751445AbdJGGyN (ORCPT ); Sat, 7 Oct 2017 02:54:13 -0400 X-ME-Sender: X-Sasl-enc: UD2L5hhdZOdqFOy8/6NBYSe/JevYzjX/68E5+es+N6vB 1507359252 Date: Sat, 7 Oct 2017 08:54:21 +0200 From: Greg KH To: Mario Limonciello Cc: dvhart@infradead.org, Andy Shevchenko , LKML , platform-driver-x86@vger.kernel.org, Andy Lutomirski , quasisec@google.com, pali.rohar@gmail.com, rjw@rjwysocki.net, mjg59@google.com, hch@lst.de Subject: Re: [PATCH v5 08/14] platform/x86: dell-smbios: Add a sysfs interface for SMBIOS tokens Message-ID: <20171007065421.GA20756@kroah.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 06, 2017 at 11:59:52PM -0500, Mario Limonciello wrote: > Currently userspace tools can access system tokens via the dcdbas > kernel module and a SMI call that will cause the platform to execute > SMM code. > > With a goal in mind of deprecating the dcdbas kernel module a different > method for accessing these tokens from userspace needs to be created. > > This is intentionally marked to only be readable as root as it can > contain sensitive information about the platform's configuration. > > MAINTAINERS was missing for this driver. Add myself and Pali to > maintainers list for it. > > Signed-off-by: Mario Limonciello > --- > .../ABI/testing/sysfs-platform-dell-smbios | 16 ++++++ > MAINTAINERS | 7 +++ > drivers/platform/x86/dell-smbios.c | 64 ++++++++++++++++++++++ > 3 files changed, 87 insertions(+) > create mode 100644 Documentation/ABI/testing/sysfs-platform-dell-smbios > > diff --git a/Documentation/ABI/testing/sysfs-platform-dell-smbios b/Documentation/ABI/testing/sysfs-platform-dell-smbios > new file mode 100644 > index 000000000000..d97f4bd5bd91 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-platform-dell-smbios > @@ -0,0 +1,16 @@ > +What: /sys/devices/platform//tokens > +Date: November 2017 > +KernelVersion: 4.15 > +Contact: "Mario Limonciello" > +Description: > + A read-only description of Dell platform tokens > + available on the machine. > + > + The tokens will be displayed in the following > + machine readable format with each token on a > + new line: > + > + ID Location value > + > + For example token: > + 5 5 3 That's more than "one value per file" which is what sysfs requires, so this isn't acceptable, sorry. > +static ssize_t tokens_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + size_t off = 0; > + int to_print; > + int i; > + > + to_print = min(da_num_tokens, (int)(PAGE_SIZE - 1) / 15); > + for (i = 0; i < to_print; i++) { > + off += scnprintf(buf+off, PAGE_SIZE-off, "%04x\t%04x\t%04x\n", > + da_tokens[i].tokenID, da_tokens[i].location, > + da_tokens[i].value); Huge hint, if you are checking for the max size of the buffer for sysfs, something is really wrong, and you need to redo your design. thanks, greg k-h