sigreturn - return from signal handler and cleanup stack
int sigreturn(unsigned long __unused));
When the Linux kernel creates the stack frame for a signal
handler, a call to sigreturn is inserted into the stack
frame so that the the signal handler will call sigreturn
upon return. This inserted call to sigreturn cleans up the
stack so that the process can restart from where it was
interrupted by the signal.
sigreturn never returns.
The sigreturn call is used by the kernel to implement signal
handlers. It should never be called directly. Better yet,
the specific use of the __unused argument varies depending
on the architecture.
sigreturn is specific to Linux and should not be used in
programs intended to be portable.
kill(2), signal(2), signal(7)