'break' system call man page is missing?

[Yuri]

I can't find man page for system call break.
/usr/src/lib/libc/sys/ seems to have sources for many man pages but not for break.

In the mean time in one case it fails for me with errno=22 (Invalid argument).
Is it's argument (pointer) related to /proc/##/map? One of the blocks mentioned
in this map file has upper limit equal to the argument pointer of break.

What is the condition when errno=22 is returned?

Thanks,
Yuri