Landon Fuller explains Apple’s implementation of imp_implementationWithBlock() and posted his own PLBlockIMP, which works on Mac OS X 10.6: On Darwin, vm_remap() provides support for mapping an existing code page at new address, while retaining the existing page protections; using vm_remap(), we can create multiple copies of existing, executable code, placed at arbitrary addresses. If … Continue reading Implementing imp_implementationWithBlock()