calls are typically indirect – carry a virtual-call overheadWindows 8binary … .idata Import data section 9.idata contents Directory Table Directory entry: • DLL Name • ImportLookupTable offset • … … https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#the-idata-section 10 * Actually in section .rdata… .idata lib1: f1, f2, f3 lib2: g1, g2, g3 Windows Schematic Interface 11Linux symbol names 13lib1, lib2 f1, f2, f3, g1,g2,g3 … code data .dynamic .dynsim … code data .idata lib1: f1, f2, f3 lib2: g1, g2, g3 14Interposition • Overriding a symbol in one binary from another