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SIGRETURN(2)		  FreeBSD System Calls Manual		  SIGRETURN(2)

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.

FreeBSD	11.1		       September 6, 2013		  FreeBSD 11.1

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | HISTORY

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