Question

In C, what will happens to a thread’s execution stack if a function does not return?

void funcB() __attribute__ ((noreturn));

int funcA (...)
{
   // do stuff
   funcB();
   // do more stuff
}

An example of this situation is, says, funcA is the kernel function that creates a new thread and funcB is kernel code that switches the new thread to user mode and let it run.

Thank you.

Answer 1

Have you seen this? http://gcc.gnu.org/onlinedocs/gcc-4.3.2//gcc/Function-Attributes.html

As it says in the section about noreturn:

Do not assume that registers saved by the calling function are restored before calling the noreturn function.

I assume this means that there is no guarantee that, for example, the stack pointer (or other stack frame elements) will be restored after the noreturn function finishes.