SIGRETURN(2) Linux Programmer's Manual SIGRETURN(2)
sigreturn - return from signal handler and cleanup stack frame
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 sig-
nal 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)
Linux 1.3.20 1995-08-21 SIGRETURN(2)