Comment by jebarker
3 hours ago
Reading this was a good reminder not to be intimidated by assumptions about complexity. (Without giving it much thought) I would have assumed that it would be hard to replace malloc for such fundamental applications as ls, but it's surprisingly simple.
There's usually an easy-ish way to override malloc/calloc/realloc/free on Unix, as it's very useful to do when debugging issues or just to collect allocation metrics.
In ELF objects (i.e. on Linux) this is usually done with the "Weak" symbol binding. This is an optional flag for symbols in ELF format that let you override a symbol by providing a competing non-weak symbol, which the linker will prefer when there is a conflict. https://en.wikipedia.org/wiki/Weak_symbol
You can see the list of Weak symbols by looking for a 'W' in the output of `nm` on linux hosts.