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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 9F9D6C433E1 for ; Thu, 4 Jun 2020 09:16:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7954E2065C for ; Thu, 4 Jun 2020 09:16:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="lpIhailS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727898AbgFDJQf (ORCPT ); Thu, 4 Jun 2020 05:16:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726567AbgFDJQe (ORCPT ); Thu, 4 Jun 2020 05:16:34 -0400 Received: from mail-yb1-xb42.google.com (mail-yb1-xb42.google.com [IPv6:2607:f8b0:4864:20::b42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45607C03E96D for ; Thu, 4 Jun 2020 02:16:34 -0700 (PDT) Received: by mail-yb1-xb42.google.com with SMTP id y13so2576063ybj.10 for ; Thu, 04 Jun 2020 02:16:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=EZ/1OA1lIfkBZzGhY/7MgoW8R4VpB8ChGNgUuwxq9eI=; b=lpIhailSAHTDLeRhiB9ZtjJ0QiY2pjYaNPivllIVOQxUjafhECX7wzRtPm4wt7ocGZ yIbe1HyFhPgCisQUbqfx4i5UTJ5spb9z0ySzBeeyPv+gXmwFG3ZYC5kRwNQZxS+D+UZI IMiV4/wQ2SnGXxUM6FCEj+n7rkLfLw9Z29pOzfpC+U+ceurlbYVa3XM5eQMD+mLTtp1U YRXfrfrG+RfHNQvtuSIfDBxFFe1Ep8fBxsXs5+t9LnbPCo+SYJ6fRBE+r+MMyW12hmw6 KRVkpIYXpAX8/yW8Ywf2uKYpf2mAW8DZwzfMfFsI1F2qMHFeFIsnQG0cc0xzdfsQogyL JyLQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=EZ/1OA1lIfkBZzGhY/7MgoW8R4VpB8ChGNgUuwxq9eI=; b=nU3lKUR9f034JEp8pp6Z6fPKC/rfnacVhI+lkpsjbWfDGlq7dORL9HFlAJchmFYiq7 M53NAs76Sw4mhBhpNhevxLjRii8nA1VH+CCD6DecOTM0axlP74g9VXeAOx4s3lfzd2Ma vwjvXTNeqlRzp5qIQ7A5yHqPdlx9wb/zRpozvXoBvPszuq4qiZbocEAv40N4/dOLejrB fim3Gjz2JXpn5JdjzkJhhGKIGftkF+nJtF+kw+SIIQU8/UH6dDSBkH6Zy7/+bjUOwOHn 09SgGNlv5hN+ZvVCK51m0kwcMsjxtT0jADOduyKnsJlONvLZrMSF9a1l90bhdm/twzeA x3Lw== X-Gm-Message-State: AOAM530nwD3ikJkd74emqaowO9PDG8pK+qne7W+ZIbPRWIDUz7oskurf Yg/kVl4ytQ9rgeFXYz0JPr3JCAZgZnfFHUM4cZC2pA== X-Google-Smtp-Source: ABdhPJznz7G/EiOx2AkWCjZzyX47+72QghNX17aKbkdplodgFQ31LTBq32m8EB6m6azYa8JVUqYhyHay+txWPeD0zw0= X-Received: by 2002:a5b:345:: with SMTP id q5mr6093715ybp.494.1591262192787; Thu, 04 Jun 2020 02:16:32 -0700 (PDT) MIME-Version: 1.0 References: <20200601150645.13412-1-maxim.uvarov@linaro.org> <20200601150645.13412-2-maxim.uvarov@linaro.org> <20200604083655.GA4026@linux.intel.com> In-Reply-To: <20200604083655.GA4026@linux.intel.com> From: Maxim Uvarov Date: Thu, 4 Jun 2020 12:16:21 +0300 Message-ID: Subject: Re: [PATCHv6 1/3] optee: use uuid for sysfs driver entry To: Jarkko Sakkinen Cc: Linux Kernel Mailing List , "tee-dev @ lists . linaro . org" , peterhuewe@gmx.de, Jason Gunthorpe , Greg Kroah-Hartman , Jens Wiklander , linux-integrity@vger.kernel.org, Arnd Bergmann , Sumit Garg Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 4 Jun 2020 at 11:37, Jarkko Sakkinen wrote: > > On Mon, Jun 01, 2020 at 06:06:43PM +0300, Maxim Uvarov wrote: > > With the evolving use-cases for TEE bus, now it's required to support > > multi-stage enumeration process. But using a simple index doesn't > > suffice this requirement and instead leads to duplicate sysfs entries. > > So instead switch to use more informative device UUID for sysfs entry > > like: > > /sys/bus/tee/devices/optee-ta- > > > > Signed-off-by: Maxim Uvarov > > Reviewed-by: Sumit Garg > > Why do you mean by duplicate sysfs entries? > Without this change it will try to register something like that: first stage w/o tee-supplicant: /sys/bus/tee/devices/optee-clnt0 /sys/bus/tee/devices/optee-clnt1 /sys/bus/tee/devices/optee-clnt3 Then with tee-supplicant also index started with 0. I.e. /sys/bus/tee/devices/optee-clnt0 /sys/bus/tee/devices/optee-clnt1 ... So we need to increase global index or use some other unique names. > > --- > > Documentation/ABI/testing/sysfs-bus-optee-devices | 8 ++++++++ > > MAINTAINERS | 1 + > > drivers/tee/optee/device.c | 6 +++--- > > 3 files changed, 12 insertions(+), 3 deletions(-) > > create mode 100644 Documentation/ABI/testing/sysfs-bus-optee-devices > > > > diff --git a/Documentation/ABI/testing/sysfs-bus-optee-devices b/Documentation/ABI/testing/sysfs-bus-optee-devices > > new file mode 100644 > > index 000000000000..0ae04ae5374a > > --- /dev/null > > +++ b/Documentation/ABI/testing/sysfs-bus-optee-devices > > @@ -0,0 +1,8 @@ > > +What: /sys/bus/tee/devices/optee-ta-/ > > +Date: May 2020 > > +KernelVersion 5.7 > > +Contact: tee-dev@lists.linaro.org > > +Description: > > + OP-TEE bus provides reference to registered drivers under this directory. The > > + matches Trusted Application (TA) driver and corresponding TA in secure OS. Drivers > > + are free to create needed API under optee-ta- directory. > > diff --git a/MAINTAINERS b/MAINTAINERS > > index ecc0749810b0..6717afef2de3 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -12516,6 +12516,7 @@ OP-TEE DRIVER > > M: Jens Wiklander > > L: tee-dev@lists.linaro.org > > S: Maintained > > +F: Documentation/ABI/testing/sysfs-bus-optee-devices > > F: drivers/tee/optee/ > > > > OP-TEE RANDOM NUMBER GENERATOR (RNG) DRIVER > > diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c > > index e3a148521ec1..ed3d1ddfa52b 100644 > > --- a/drivers/tee/optee/device.c > > +++ b/drivers/tee/optee/device.c > > @@ -65,7 +65,7 @@ static int get_devices(struct tee_context *ctx, u32 session, > > return 0; > > } > > > > -static int optee_register_device(const uuid_t *device_uuid, u32 device_id) > > +static int optee_register_device(const uuid_t *device_uuid) > > { > > struct tee_client_device *optee_device = NULL; > > int rc; > > @@ -75,7 +75,7 @@ static int optee_register_device(const uuid_t *device_uuid, u32 device_id) > > return -ENOMEM; > > > > optee_device->dev.bus = &tee_bus_type; > > - dev_set_name(&optee_device->dev, "optee-clnt%u", device_id); > > + dev_set_name(&optee_device->dev, "optee-ta-%pUl", device_uuid); > > This code is and already was broken. If dev_set_name() returns -ENOMEM, > the name will be a null pointer. > Well in the current code base only 1% of drivers check the return code of dev_set_name(). But I don't mind adding this check. > Also, I don't get how you can just swap the name without potentially > breaking the backwards compatiblity towards the user space. > > /Jarkko Backwards compatibility to what? API (stable, testing) are defined in Documentation. There was no doc for that. And user get notifications on uevent, so it's udev deal how to find proper sysfs entry. Regards, Maxim.