Hmm, why won't it? Maybe in the past when asprintf and malloc were located in the same dylib, since OS X dylibs generate direct calls to other public functions

Hmm, why won't it? Maybe in the past when asprintf and malloc were located in the same dylib, since OS X dylibs generate direct calls to other public functions in the same image (rather than going through the PLT as GNU does by default), but for many years /usr/lib/libSystem.B.dylib has been split into several reexported libraries in /usr/lib/system, so there shouldn't be an issue there. Probably better to use this technique though (should still work in the latest version but needs mprotect): http://eatmyrandom.blogspot.com/2010/03/mallocfree-interception-on-mac-os-x.html http://eatmyrandom.blogspot.com/2010/03/mallocfree-intercept...