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_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED 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 C9353C43381 for ; Mon, 25 Mar 2019 06:15:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8AD7F2075E for ; Mon, 25 Mar 2019 06:15:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="PjqA5DBt"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="KcAHlfzq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729632AbfCYGPV (ORCPT ); Mon, 25 Mar 2019 02:15:21 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:37438 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729400AbfCYGPU (ORCPT ); Mon, 25 Mar 2019 02:15:20 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 699396115A; Mon, 25 Mar 2019 06:15:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1553494519; bh=4Rvin1v8IwARcNic8g6j6fd4jMyBSTXjvFhZjHpn9wg=; h=Subject:From:To:Cc:References:Date:In-Reply-To:From; b=PjqA5DBtFqyWepamCTw4qa1QCUSwiy31rLcTE1Bez5ReB6OTd+pjWxVVb4clUfs15 9b6kVXc8OPG2duNhGvGulkCiw6m3tQytKs8VqywFgiTYcAy8dI4GUtn7V1747lii5p k1DM9vHUntKs2KEpWenORMZuFaeUkrVxTMjrzf54= Received: from [10.204.78.115] (blr-c-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: gkohli@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 140AB60DB2; Mon, 25 Mar 2019 06:15:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1553494517; bh=4Rvin1v8IwARcNic8g6j6fd4jMyBSTXjvFhZjHpn9wg=; h=Subject:From:To:Cc:References:Date:In-Reply-To:From; b=KcAHlfzqzmflZxm9aV7bIiictl87hoFPm7FUuQgGzJH7JhxrTUUhQXWWEnkSydntT vAF1nQGfeP2NE03P+xp+rVjwALeF1QvpDSHpSXhWAEzX7AUnXG1WFUgOcv+ZdFE1EI nemo3r8SZ8lNpmaOqQKExY5Sc7HuCGZK+rDQ1Cts= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 140AB60DB2 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=gkohli@codeaurora.org Subject: Re: [PATCH v2] nvmem: core: Set no-read-write provider to avoid userspace read/write From: Gaurav Kohli To: Srinivas Kandagatla , linux-kernel@vger.kernel.org Cc: linux-arm-msm@vger.kernel.org References: <1552831940-7327-1-git-send-email-gkohli@codeaurora.org> <48a71861-c60b-7fe7-d4af-5269cd7c20eb@linaro.org> <5f11070f-bf9b-c313-9a78-e412a2fb2908@codeaurora.org> <865519b5-62c9-3eb3-3855-eebf98bded85@linaro.org> <68755fdb-b2c6-ac25-a786-7593a692a173@codeaurora.org> <4451d4f2-d651-9db6-99af-e07870fc699a@codeaurora.org> Message-ID: Date: Mon, 25 Mar 2019 11:45:13 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.0 MIME-Version: 1.0 In-Reply-To: <4451d4f2-d651-9db6-99af-e07870fc699a@codeaurora.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/22/2019 11:42 PM, Gaurav Kohli wrote: > Hi Srinivas, > > Thanks for the patch, Something like this only i have tested in the > morning, instead of unused, i have put dev group inside config as well. > > We will test the exact patch and update the same. > > Regards > > Gaurav > > On 3/22/2019 8:32 PM, Srinivas Kandagatla wrote: >> >> >> On 20/03/2019 17:50, Gaurav Kohli wrote: >>> >>>> Is root only option not helping you in this case? >>> Yes we want to protect at root level as well, i mean it is better if >>> we can avoid exposing to userspace at all. >> Can you try below patch! >> Hi Srinivas, Thanks for the patch. I have checked the patch and also tested the same , and it is working as expected(no creation of nvmem sysfs) Applied with some conflict on line 41. Reviewed-by: Gaurav Kohli Tested-by: Gaurav Kohli Regards Gaurav >>>> >>>> We could go down the route of adding new config option something >>>> like CONFIG_NVMEM_NO_SYSFS_ENTRY to prevent adding nvmem entry in >>>> userspace. >>>> >>>> Let me know if you are happy to create a patch for this change? >>> >>> I am happy with either way config option or dt binding(seems easy), >>> please let me know we will post new patch for the same. >> DT way is totally NAK. >> >> >> --------------------------->cut<----------------------------------- >> >> From: Srinivas Kandagatla >> Date: Wed, 20 Mar 2019 16:15:21 +0000 >> Subject: [PATCH] nvmem: core: add support to NVMEM_NO_SYSFS_ENTRY >> >> Some users might not want to expose nvmem entry to sysfs and >> only intend to use kernel interface so add such provision. >> >> Signed-off-by: Srinivas Kandagatla >> --- >>  Documentation/ABI/stable/sysfs-bus-nvmem |  2 ++ >>  drivers/nvmem/Kconfig                    |  5 +++++ >>  drivers/nvmem/core.c                     | 11 ++++++----- >>  3 files changed, 13 insertions(+), 5 deletions(-) >> >> diff --git a/Documentation/ABI/stable/sysfs-bus-nvmem >> b/Documentation/ABI/stable/sysfs-bus-nvmem >> index 5923ab4620c5..12aab0a85fea 100644 >> --- a/Documentation/ABI/stable/sysfs-bus-nvmem >> +++ b/Documentation/ABI/stable/sysfs-bus-nvmem >> @@ -6,6 +6,8 @@ Description: >>          This file allows user to read/write the raw NVMEM contents. >>          Permissions for write to this file depends on the nvmem >>          provider configuration. >> +        Note: This file is not present if CONFIG_NVMEM_NO_SYSFS_ENTRY >> +        is enabled >> >>          ex: >>          hexdump /sys/bus/nvmem/devices/qfprom0/nvmem >> diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig >> index 0a7a470ee859..6ab3276d287c 100644 >> --- a/drivers/nvmem/Kconfig >> +++ b/drivers/nvmem/Kconfig >> @@ -192,4 +192,9 @@ config SC27XX_EFUSE >>        This driver can also be built as a module. If so, the module >>        will be called nvmem-sc27xx-efuse. >> >> +config NVMEM_NO_SYSFS_ENTRY >> +    bool "No nvmem sysfs entry" >> + >> +    help >> +        Say Yes if you do not want to add nvmem entry to sysfs. >>  endif >> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c >> index b9a0270883a0..c70f183fe379 100644 >> --- a/drivers/nvmem/core.c >> +++ b/drivers/nvmem/core.c >> @@ -216,7 +216,7 @@ static const struct attribute_group >> nvmem_bin_rw_group = { >>      .attrs        = nvmem_attrs, >>  }; >> >> -static const struct attribute_group *nvmem_rw_dev_groups[] = { >> +static const __maybe_unused struct attribute_group >> *nvmem_rw_dev_groups[] = { >>      &nvmem_bin_rw_group, >>      NULL, >>  }; >> @@ -240,7 +240,7 @@ static const struct attribute_group >> nvmem_bin_ro_group = { >>      .attrs        = nvmem_attrs, >>  }; >> >> -static const struct attribute_group *nvmem_ro_dev_groups[] = { >> +static const __maybe_unused struct attribute_group >> *nvmem_ro_dev_groups[] = { >>      &nvmem_bin_ro_group, >>      NULL, >>  }; >> @@ -265,7 +265,7 @@ static const struct attribute_group >> nvmem_bin_rw_root_group = { >>      .attrs        = nvmem_attrs, >>  }; >> >> -static const struct attribute_group *nvmem_rw_root_dev_groups[] = { >> +static const __maybe_unused struct attribute_group >> *nvmem_rw_root_dev_groups[] = { >>      &nvmem_bin_rw_root_group, >>      NULL, >>  }; >> @@ -289,7 +289,7 @@ static const struct attribute_group >> nvmem_bin_ro_root_group = { >>      .attrs        = nvmem_attrs, >>  }; >> >> -static const struct attribute_group *nvmem_ro_root_dev_groups[] = { >> +static const __maybe_unused struct attribute_group >> *nvmem_ro_root_dev_groups[] = { >>      &nvmem_bin_ro_root_group, >>      NULL, >>  }; >> @@ -688,6 +688,7 @@ struct nvmem_device *nvmem_register(const struct >> nvmem_config *config) >>      nvmem->read_only = device_property_present(config->dev, >> "read-only") | >>                 config->read_only; >> >> +#if !defined(CONFIG_NVMEM_NO_SYSFS_ENTRY) >>      if (config->root_only) >>          nvmem->dev.groups = nvmem->read_only ? >>              nvmem_ro_root_dev_groups : >> @@ -696,7 +697,7 @@ struct nvmem_device *nvmem_register(const struct >> nvmem_config *config) >>          nvmem->dev.groups = nvmem->read_only ? >>              nvmem_ro_dev_groups : >>              nvmem_rw_dev_groups; >> - >> +#endif >>      device_initialize(&nvmem->dev); >> >>      dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", >> config->name); > -- Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.