malloc_size alternative on Linux and Windows

Question

How can one tell, given a void * pointer, what is the size of a block allocated on this given address (previously allocated using malloc; in Linux and Windows)? I hope both systems surely store this kind of information somewhere. That is, alternative of malloc_size which exists on OSX/Darwin. Using gcc/mingw if it helps.

Answer 1

On Windows, things that use the MS CRT can use _msize, on Linux you could try malloc_usable_size...