Commit b260fccaeb ("firmware: arm_scmi: Add SCMI v3.1 protocol extended
names support") moved all the name string buffers to use the extended buffer
size of 64 instead of the required 16 bytes. While that should be fine if
the firmware terminates the string before 16 bytes, there is possibility
of copying random data if the name is not NULL terminated by the firmware.
SCMI base protocol agent_name/vendor_id/sub_vendor_id are defined by the
specification as NULL-terminated ASCII strings up to 16-bytes in length.
The underlying buffers and message descriptors are currently bigger than
needed; resize them to fit only the strictly needed 16 bytes to avoid
any possible leaks when reading data from the firmware.
Change the size argument of strlcpy to use SCMI_SHORT_NAME_MAX_SIZE always
when dealing with short domain names, so as to limit the possibility that
an ill-formed non-NULL terminated short reply from the SCMI platform
firmware can leak stale content laying in the underlying transport shared
memory area.
While at that, convert all strings handling routines to use the preferred
strscpy.
Link: https://lore.kernel.org/r/20220608095530.497879-1-cristian.marussi@arm.com
Fixes: b260fccaeb ("firmware: arm_scmi: Add SCMI v3.1 protocol extended names support")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
SCMI specification defines some commands as optionally issued over multiple
messages in order to overcome possible limitations in payload size enforced
by the configured underlyinng transport.
Introduce some common protocol helpers to provide a unified solution for
issuing such SCMI multi-part commands.
Link: https://lore.kernel.org/r/20220330150551.2573938-14-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Using the common protocol helper implementation add support for all new
SCMIv3.1 extended names commands related to all protocols with the
exception of SENSOR_AXIS_GET_NAME.
Link: https://lore.kernel.org/r/20220330150551.2573938-12-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Introduce a new set of common protocol operations bound to the protocol
handle structure so that can be invoked by the protocol implementation code
even when protocols are built as distinct loadable kernel module without
the need of exporting new symbols, like already done with scmi_xfer_ops.
Add at first, as new common protocol helper, an .extended_name_get helper
which will ease implementation and will avoid code duplication when adding
new SCMIv3.1 per-protocol _NAME_GET commands.
Link: https://lore.kernel.org/r/20220330150551.2573938-11-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Move some SCMI protocol specific definitions from common.h into a the new
dedicated protocols.h header so that SCMI protocols core code can include
only what it needs; this is going to be useful to avoid the risk of growing
indefinitely the dimension of common.h, especially when introducing some
common protocols helper functions.
Header common.h will continue to be included by SCMI core and transport
layers.
Link: https://lore.kernel.org/r/20220330150551.2573938-10-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Cristian Marussi