From: Andrew Lunn <andrew@lunn.ch>
To: GregKH <greg@kroah.com>
Cc: srinivas.kandagatla@linaro.org, maxime.ripard@free-electrons.com,
wsa@the-dreams.de, broonie@kernel.org, vz@mleia.com, fd@ti.com,
linux-kernel@vger.kernel.org, pantelis.antoniou@konsulko.com,
bgolaszewski@baylibre.com, Andrew Lunn <andrew@lunn.ch>
Subject: [PATCHv4 1/7] nvmem: Add flag to export NVMEM to root only
Date: Wed, 17 Feb 2016 00:41:31 +0100 [thread overview]
Message-ID: <1455666097-9115-2-git-send-email-andrew@lunn.ch> (raw)
In-Reply-To: <1455666097-9115-1-git-send-email-andrew@lunn.ch>
Legacy AT24, AT25 EEPROMs are exported in sys so that only root can
read the contents. The EEPROMs may contain sensitive information. Add
a flag so the provide can indicate that NVMEM should also restrict
access to root only.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
drivers/nvmem/core.c | 57 ++++++++++++++++++++++++++++++++++++++++--
include/linux/nvmem-provider.h | 1 +
2 files changed, 56 insertions(+), 2 deletions(-)
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 6fd4e5a5ef4a..4ccf03da6467 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -155,6 +155,53 @@ static const struct attribute_group *nvmem_ro_dev_groups[] = {
NULL,
};
+/* default read/write permissions, root only */
+static struct bin_attribute bin_attr_rw_root_nvmem = {
+ .attr = {
+ .name = "nvmem",
+ .mode = S_IWUSR | S_IRUSR,
+ },
+ .read = bin_attr_nvmem_read,
+ .write = bin_attr_nvmem_write,
+};
+
+static struct bin_attribute *nvmem_bin_rw_root_attributes[] = {
+ &bin_attr_rw_root_nvmem,
+ NULL,
+};
+
+static const struct attribute_group nvmem_bin_rw_root_group = {
+ .bin_attrs = nvmem_bin_rw_root_attributes,
+};
+
+static const struct attribute_group *nvmem_rw_root_dev_groups[] = {
+ &nvmem_bin_rw_root_group,
+ NULL,
+};
+
+/* read only permission, root only */
+static struct bin_attribute bin_attr_ro_root_nvmem = {
+ .attr = {
+ .name = "nvmem",
+ .mode = S_IRUSR,
+ },
+ .read = bin_attr_nvmem_read,
+};
+
+static struct bin_attribute *nvmem_bin_ro_root_attributes[] = {
+ &bin_attr_ro_root_nvmem,
+ NULL,
+};
+
+static const struct attribute_group nvmem_bin_ro_root_group = {
+ .bin_attrs = nvmem_bin_ro_root_attributes,
+};
+
+static const struct attribute_group *nvmem_ro_root_dev_groups[] = {
+ &nvmem_bin_ro_root_group,
+ NULL,
+};
+
static void nvmem_release(struct device *dev)
{
struct nvmem_device *nvmem = to_nvmem_device(dev);
@@ -347,8 +394,14 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
nvmem->read_only = of_property_read_bool(np, "read-only") |
config->read_only;
- nvmem->dev.groups = nvmem->read_only ? nvmem_ro_dev_groups :
- nvmem_rw_dev_groups;
+ if (config->root_only)
+ nvmem->dev.groups = nvmem->read_only ?
+ nvmem_ro_root_dev_groups :
+ nvmem_rw_root_dev_groups;
+ else
+ nvmem->dev.groups = nvmem->read_only ?
+ nvmem_ro_dev_groups :
+ nvmem_rw_dev_groups;
device_initialize(&nvmem->dev);
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
index 0b68caff1b3c..d24fefa0c11d 100644
--- a/include/linux/nvmem-provider.h
+++ b/include/linux/nvmem-provider.h
@@ -23,6 +23,7 @@ struct nvmem_config {
const struct nvmem_cell_info *cells;
int ncells;
bool read_only;
+ bool root_only;
};
#if IS_ENABLED(CONFIG_NVMEM)
--
2.7.0
next prev parent reply other threads:[~2016-02-16 23:42 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-16 23:41 [PATCHv4 0/7] Convert exiting EEPROM drivers to NVMEM Andrew Lunn
2016-02-16 23:41 ` Andrew Lunn [this message]
2016-02-17 10:17 ` [PATCHv4 1/7] nvmem: Add flag to export NVMEM to root only Srinivas Kandagatla
2016-02-17 13:32 ` Andrew Lunn
2016-02-16 23:41 ` [PATCHv4 2/7] nvmem: Add backwards compatibility support for older EEPROM drivers Andrew Lunn
2016-02-17 10:17 ` Srinivas Kandagatla
2016-02-17 13:27 ` Andrew Lunn
2016-02-16 23:41 ` [PATCHv4 3/7] eeprom: at24: extend driver to plug into the NVMEM framework Andrew Lunn
2016-02-17 10:17 ` Srinivas Kandagatla
2016-02-17 10:21 ` Wolfram Sang
2016-02-17 11:00 ` Srinivas Kandagatla
2016-02-17 11:00 ` Srinivas Kandagatla
2016-02-16 23:41 ` [PATCHv4 4/7] eeprom: at25: Remove in kernel API for accessing the EEPROM Andrew Lunn
2016-02-17 10:17 ` Srinivas Kandagatla
2016-02-16 23:41 ` [PATCHv4 5/7] eeprom: at25: extend driver to plug into the NVMEM framework Andrew Lunn
2016-02-17 10:17 ` Srinivas Kandagatla
2016-02-17 13:42 ` Andrew Lunn
2016-02-17 13:45 ` Srinivas Kandagatla
2016-02-16 23:41 ` [PATCHv4 6/7] eeprom: 93xx46: " Andrew Lunn
2016-02-17 10:17 ` Srinivas Kandagatla
2016-02-17 13:46 ` Srinivas Kandagatla
2016-02-16 23:41 ` [PATCHv4 7/7] misc: at24: replace memory_accessor with nvmem_device_read Andrew Lunn
2016-02-17 10:18 ` Srinivas Kandagatla
2016-02-17 10:17 ` [PATCHv4 0/7] Convert exiting EEPROM drivers to NVMEM Srinivas Kandagatla
2016-02-17 13:39 ` Andrew Lunn
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