The CXL NVDIMM security passphrase key description and the nvdimm 'id'
sysfs attribute are both derived from the CXL device serial number,
but the serial number is not formatted consistently.
The key description is formatted in hexadecimal while the 'id'
attribute is formatted in decimal. As a result, ndctl stores the key
using a decimal description while the kernel later looks it up using
a hexadecimal description. For serial numbers of 10 and above, the
descriptions no longer match, preventing automatic unlock after
reboot.
The decimal formatting has a second problem: both the key description
and the 'id' attribute use the signed %lld format for a u64 PCIe
Device Serial Number. Devices whose vendor OUI sets bit 63, such as
Montage CXL devices, appear with negative decimal serial numbers.
Format the security key description and 'id' attribute as unsigned
decimal, %llu, and document that the 'id' attribute is an unsigned
decimal value.
The key lookup mismatch was exposed by CXL unit test cxl-security.sh
when cxl_test mock serial numbers were extended to 10 and above.
A work around is described for ndctl load-key users here:
https://github.com/pmem/ndctl/issues/299
Cc: stable@vger.kernel.org
Fixes: b5807c80b5 ("cxl: add dimm_id support for __nvdimm_create()")
Acked-by: Dan Williams <djbw@kernel.org>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/2c673a5ba0a8fa93ad160578e193bd556091fa95.1784924949.git.alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
8a80d3d65c