> I am just hooking linux kernel calls, I will never take JS for this. Pure C.
Why not? Hooking native code in other languages is already fairly common: http://www.cycript.org
> Valgrind? I have a header with #define MALLOC/FREE/REALLOC/... which returns larger buffer with guards at beginning and the end while after 25 years of C I hardly do anything more problematic that this.
Valgrind does significantly more checks than your solution.
> System language? Make it.
"Systems language" is a very ill-defined term, often used to gatekeep people.
> If it is just a newage nonsense wasting resources for the sake of deallocating and taking care about buffer boundaries as it is so hard to take care and track your memory I will skip it.
Keeping track of your memory is hard. If you say "no, it's easy for me", I'd like to see a non-trivial sample of your code that doesn't have memory safety issues.