Backporting issue in compat.ko

[SaKr_4783036]

Hi,

I want to port driver for CYW43455. I used this  Cypress Linux WiFi Driver Release (FMAC) [2020-06-25]  release. I need to port this driver for 4.9 kernel. I followed the instructions in README file given in the backports. During the cross compilation of modules, I have seen the following warning.

WARNING: "hash_algo_name" [/Downloads/cypress/v5.4.18-backports/compat/compat.ko] undefined!

Similarly, during insmod compat.ko in the target board. I got the following error:

sakthi@localhost:~$ sudo insmod compat.ko

insmod: ERROR: could not insert module compat.ko: Unknown symbol in module

In dmesg, I got the following logs after insmod of compat.ko,

[  627.941252] compat: loading out-of-tree module taints kernel.

[  627.949143] compat: Unknown symbol hash_algo_name (err 0)

Could you please let me know how to fix this issue?

Thanks,

Sakthi

[yasa_4608926 · Accepted solution]

Hi,

"hash_algo_name" is implemented in the Linux Kernel source code "crypto/hash_info.c".

To use it, you need CONFIG_CRYPTO_HASH_INFO=y in your kernel configuration.

Please refer the README in FMAC package.

For FMAC, you need to enable the following in the kernel configuration.

#4. Enable below configs in .config

#     CONFIG_ASYMMETRIC_KEY_TYPE=y

#     CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE=y

#     CONFIG_X509_CERTIFICATE_PARSER=y

#     CONFIG_PKCS7_MESSAGE_PARSER=y

If CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE=y, CONFIG_CRYPTO_HASH_INFO will be enabled by the dependency.

Best regards,

Yasa