NAME

       sigreturn — return from signal

LIBRARY

       Standard C Library (libc, -lc)

SYNOPSIS

       #include <signal.h>

       int
       sigreturn(const ucontext_t *scp);

DESCRIPTION

       The  sigreturn()  system  call allows users to atomically unmask, switch stacks, and return from a signal
       context.  The thread's signal mask and stack status are restored from the context structure pointed to by
       scp.  The system call does not return; the users stack pointer,  frame  pointer,  argument  pointer,  and
       processor  status  longword  are restored from the context.  Execution resumes at the specified pc.  This
       system call is used by the trampoline code and longjmp(3) when returning from a signal to the  previously
       executing program.

RETURN VALUES

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

ERRORS

       The  sigreturn()  system  call  will  fail  and  the  thread  context will remain unchanged if one of the
       following occurs.

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

       [EINVAL]           The  process  status longword is invalid or would improperly raise the privilege level
                          of the process.

SEE ALSO

       sigaction(2), setjmp(3), ucontext(3)

HISTORY

       The sigreturn() system call appeared in 4.3BSD.

Debian                                          September 6, 2013                                   SIGRETURN(2)