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path: root/drivers/s390/crypto/pkey_base.c
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2024-08-29s390/pkey: Add function to enforce pkey handler modules loadHarald Freudenberger
There is a use case during early boot with an secure key encrypted root file system where the paes cipher may try to derive a protected key from secure key while the AP bus is still in the process of scanning the bus and building up the zcrypt device drivers. As the detection of CEX cards also triggers the modprobe of the pkey handler modules, these modules may come into existence too late. Yet another use case happening during early boot is for use of an protected key encrypted swap file(system). There is an ephemeral protected key read via sysfs to set up the swap file. But this only works when the pkey_pckmo module is already in - which may happen at a later time as the load is triggered via CPU feature. This patch introduces a new function pkey_handler_request_modules() and invokes it which unconditional tries to load in the pkey handler modules. This function is called for the in-kernel API to derive a protected key from whatever and in the sysfs API when the first attempt to simple invoke the handler function failed. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-29s390/pkey: Add slowpath function to CCA and EP11 handlerHarald Freudenberger
For some keys there exists an alternative but usually slower path to convert the key material into a protected key. This patch introduces a new handler function slowpath_key_to_protkey() which provides this alternate path for the CCA and EP11 handler code. With that even the knowledge about how and when this can be used within the pkey API code can be removed. So now the pkey API just tries the primary way and if that fails simple tries the alternative way. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-29s390/pkey: Introduce pkey base with handler registry and handler modulesHarald Freudenberger
Introduce pkey base kernel code with a simple pkey handler registry. Regroup the pkey code into these kernel modules: - pkey is the pkey api supporting the ioctls, sysfs and in-kernel api. Also the pkey base code which offers the handler registry and handler wrapping invocation functions is integrated there. This module is automatically loaded in via CPU feature if the MSA feature is available. - pkey-cca is the CCA related handler code kernel module a offering CCA specific implementation for pkey. This module is loaded in via MODULE_DEVICE_TABLE when a CEX[4-8] card becomes available. - pkey-ep11 is the EP11 related handler code kernel module offering an EP11 specific implementation for pkey. This module is loaded in via MODULE_DEVICE_TABLE when a CEX[4-8] card becomes available. - pkey-pckmo is the PCKMO related handler code kernel module. This module is loaded in via CPU feature if the MSA feature is available, but on init a check for availability of the pckmo instruction is performed. The handler modules register via a pkey_handler struct at the pkey base code and the pkey customer (that is currently the pkey api code fetches a handler via pkey handler registry functions and calls the unified handler functions via the pkey base handler functions. As a result the pkey-cca, pkey-ep11 and pkey-pckmo modules get independent from each other and it becomes possible to write new handlers which offer another kind of implementation without implicit dependencies to other handler implementations and/or kernel device drivers. For each of these 4 kernel modules there is an individual Kconfig entry: CONFIG_PKEY for the base and api, CONFIG_PKEY_CCA for the PKEY CCA support handler, CONFIG_PKEY_EP11 for the EP11 support handler and CONFIG_PKEY_PCKMO for the pckmo support. The both CEX related handler modules (PKEY CCA and PKEY EP11) have a dependency to the zcrypt api of the zcrypt device driver. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>