From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gaurav Kohli Subject: Re: [PATCH v2] nvmem: core: Set no-read-write provider to avoid userspace read/write Date: Mon, 1 Apr 2019 10:22:29 +0530 Message-ID: <67d71ed4-17dc-a4ff-19cd-c49a3f137fc1@codeaurora.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> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Srinivas Kandagatla , linux-kernel@vger.kernel.org Cc: linux-arm-msm@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org Hi Srinivas, Thanks for the patch, Can you please merge , So will cherry pick the same. Regards Gaurav On 3/25/2019 11:45 AM, Gaurav Kohli wrote: > > 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.