Re: [PATCH] tty: vt: keyboard: do not copy an extra-byte in copy_to_user

quoted

That's right Pavel.
Every function must work correctly as it "advertises", instead of
relying on "chancy correctness" of the calls leading to the method.

That is not how the kernel works, sorry.  Otherwise every function would
have to always verify all parameters passed to them, causing slow downs
and redundant checks everywhere.

Hmm, agreed. Every cycle saved in the kernel is performance gained.

That's why, the RFC for strlscpy [1] makes all the more sense, as it
would save cpu cycles by removing the requirement to check the
return-value for overflows/underflows (including the "issue" I am
trying to address in this particular thread, and which actually lead
to the RFC for strlscpy].

P.S. :

I am not an egoistic person, who wants to get into unnecessary fights
just to upheld one's ego.
All I am trying is to suggest improvements, that

* make things faster.
* keeps code to as minimum as possible.
* makes developers' lives as comfortable as possible.


[1]
https://lore.kernel.org/linux-hardening/CAHP4M8WnLA0780yN+bpuuCtir+DLJRxe0atAiLbZO0bTGf6J-Q@mail.gmail.com/T/#m4a3f524eefe283a42430905fa4c0dfc2c37b2819 (local)


Thanks and Regards,
Ajay