NAME
sigreturn —
return from signal
SYNOPSIS
#include
<signal.h>
int
sigreturn(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 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.
Note that sigcontext contains machine dependent information.
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.
ERRORS
sigreturn() 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 ALSO
HISTORY
The sigreturn() function call appeared in
4.3BSD.