Target injection safe method for inlining registration calls

A system comprising:

• a memory containing one or more user processes, and
• an operating system kernel having a memory code region that has a different mapping for each user process;
• and
• one or more CPUs coupled to the memory, the one or more CPUs running the operating system kernel and the one or more user processes;
• wherein the operating system kernel is configured to:
• upon registering a list of functions, determine a list of function pointers, each of which corresponds to an address in an associated callback;
• for each function pointer in the list of function pointers, add a direct call instruction to the registration trampoline corresponding to the associated callback of the function pointer;
• and
• upon invoking the associated callback of one of the function pointers in the list of function pointers, invoke the corresponding direct call instruction in the registration trampoline.

A non-transitory computer-readable medium comprising instructions executable in a computer system, wherein the instructions when executed in the computer system cause the computer system to carry out a method of redirecting an indirect call in a callback list associated with a list of functions that are registered, to a direct call in a registration trampoline, the method comprising:

• upon registering the list of functions, determining a list of function pointers, each of which corresponds to an address in an associated callback;
• for each function pointer in the list of function pointers, adding a direct call instruction to the registration trampoline corresponding to the associated callback of the function pointer;
• and
• upon invoking the associated callback of one of the function pointers in the list of function pointers, invoking the corresponding direct call instruction in the registration trampoline.