sigreturn - Returns from signal
struct sigcontext *scp) ;
scp Points to a sigcontext structure whose members contain the pro-
cessor state to be restored. The contents of the sigcontext
structure should have been previously obtained by entry to a sig-
nal handler or by the setjmp() or sigsetjmp() function.
The sigreturn() function restores the processor state of the calling pro-
cess from a sigcontext structure. The sigcontext structure contains the
state of all application-visible registers as well as the signal mask. The
specific members of the sigcontext structure depend on the machine archi-
tecture. Each machine-dependent structure member is defined in the signal.h
The sigreturn() function is used internally by the system software to
restore the processor state on return from a signal handler and from a
longjmp() function, to restore the state saved by a previous setjmp() or
An application should only use sigreturn() with great caution.
Upon successful completion, the sigreturn() function does not return. Oth-
erwise, a value of -1 is returned and errno may be set to indicate the
If the sigreturn() function fails, the process context remains unchanged
and errno is set to one of the following values:
[EFAULT] The scp parameter points to memory space that is not a valid part
of the process address space.
[EINVAL] The sigcontext structure contains unsupported or illegal values.
Functions: setjmp(3), sigaction(2), sigvec(2)