SIGRETURN(2-BSD)    RISC/os Reference Manual     SIGRETURN(2-BSD)



NAME
     sigreturn - return from signal

SYNOPSIS
     #include <signal.h>

     sigreturn(scp);
     struct sigcontext *scp;

DESCRIPTION
     sigreturn allows users to atomically unmask, switch stacks,
     and return from a signal context.  The processes signal mask
     and stack status are restored from the context.  The system
     call does not return; the users registers are restored from
     the context.  Execution resumes at the specified program
     counter (sc_pc) in the signal context structure.  This sys-
     tem call is used by the trampoline code, and longjmp (see
     setjmp(3C)) when returning from a signal to the previously
     executing program.

NOTES
     This system call is not available in 4.2BSD, hence it should
     not be used if backward compatibility is needed.

RETURN VALUE
     If successful, the system call does not return.  Otherwise,
     a value of -1 is returned and errno is set to indicate the
     error.

ERRORS
     sigreturn will fail and the process context will remain
     unchanged if the following occurs.

     [EFAULT]  scp points to memory that is not a valid part of
               the process address space.

SEE ALSO
     sigvec(2), setjmp(3C).

















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