Hello all,

Just a note to whomever is subscribed to this list regarding some changes in v5.10 that may affect distros' kernel deployments:

efivars ------- efivars is the ancient predecessor to efivarFs, that allows access to EFI variables via sysfs (but with some restrictions). This has been deprecated since before ARM even had UEFI support, and it is no longer going to be enabled going forward. EFI pstore has been rewritten to no longer rely on it, and on x86, the module is still available, but no longer gets loaded automatically. On !x86, it is no longer built at all. As far as I could figure out (and I did ask around as well), this is highly unlikely to regress anything, and on x86, the module can still be loaded manually if needed (or enabled as a builtin)

deprecated crypto ----------------- Some crypto drivers have been made to depend on CONFIG_CRYPTO_USER_API_ENABLE_OBSOLETE, which is only available if the crypto AF_ALG socket API is enabled, as the algorithms are never used by the kernel itself. However, none of these ciphers are known to be relied upon by user space either (via AF_ALG), and so I strongly recommend the distros incorporate

# CONFIG_CRYPTO_USER_API_ENABLE_OBSOLETE is not set

into their v5.10+ kernel configs so that these deprecated algorithms are simply dropped from the build (the algos are arc4, tea, khazad, SEED and anubis, others may follow in the future, e.g., md4/5). Note that iwd/libell used to rely on the kernel's ecb(arc4) implementation, but this is no longer the case.

kexec/kdump tools ----------- To make the kernel's PE/COFF header spec compliant, the stext symbol will be aligned to 64 KB regardless of the page size the kernel was built with. As far as I can tell looking at the debian source of the associated tooling, the symbol value of stext is used to infer the page size, so this will no longer work.