[burfog]

The moment you call sbrk or mmap, you're outside of standard C, so no. Treating a pointer as an integer in order to mess with the bits is also a violation.

Aside from that, the style used here is probably OK. It is hard to say what exactly would trigger the gcc bugs, but I'm pretty sure that a recent gcc would be OK for this code.

[nemetroid]

> Treating a pointer as an integer in order to mess with the bits is also a violation.

Violation of what exactly? Converting a pointer to an integer, and vice versa, is implementation defined. As long as you're not trying to write implementation-independent code, it's perfectly fine.

[burfog]

Sure, you can convert, but the whole point of converting is to do things that violate the C standard. In theory, a standard-conforming C implementation could have the bits of a pointer be encrypted by the CPU. There is nothing meaningful that you could do to those bits. Rounding pointers up or down for alignment is impossible in standards-conforming C code.