Audit Interface Limitations

There are some limitations to the use of the la_pltexit() family. These limitations stem from the need to insert an extra stack frame between the caller and callee to provide a la_pltexit() return value. This requirement is not a problem when calling just the la_pltenter() routines, as. In this case, any intervening stack can be cleaned up prior to transferring control to the destination function.

Because of these limitations, la_pltexit() should be considered an experimental interface. When in doubt, avoid the use of the la_pltexit() routines.

Functions That Directly Inspect the Stack

A small number of functions exist that directly inspect the stack or make assumptions of its state. Some examples of these functions are the setjmp(3C) family, vfork(2), and any function that returns a structure, not a pointer to a structure. These functions are compromised by the extra stack created to support la_pltexit().

The runtime linker cannot detect functions of this type, and thus the audit library creator is responsible for disabling la_pltexit() for such routines.