SIGRETURN(2) BSD System Calls Manual SIGRETURN(2)NAMEsigreturn — return from signal
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <signal.h>
int
sigreturn(ucontext_t *scp);
DESCRIPTIONSigreturn() 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 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 previ‐
ously executing program.
NOTES
This system call is not available in 4.2BSD hence it should not be used
if backward compatibility is needed.
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.
ERRORSSigreturn() will fail and the process context will remain unchanged if
one of the following occurs.
[EFAULT] Scp 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 ALSOsigvec(2), setjmp(3), ucontext(3)HISTORY
The sigreturn() function call appeared in 4.3BSD.
BSD June 4, 1993 BSD