Messages in this thread | | | Subject | Re: [PATCH v2] nvmem: core: Set no-read-write provider to avoid userspace read/write | From | Gaurav Kohli <> | Date | Fri, 22 Mar 2019 23:42:43 +0530 |
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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! > >>> >>> 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 <srinivas.kandagatla@linaro.org> > 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 <srinivas.kandagatla@linaro.org> > --- > 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);
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