freebsd-nq/sys/sys/ucontext.h
Daniel Eischen 2be05b70c9 Add getcontext, setcontext, and swapcontext as system calls.
Previously these were libc functions but were requested to
be made into system calls for atomicity and to coalesce what
might be two entrances into the kernel (signal mask setting
and floating point trap) into one.

A few style nits and comments from bde are also included.

Tested on alpha by: gallatin
2002-11-16 06:35:53 +00:00

93 lines
3.0 KiB
C

/*-
* Copyright (c) 1999 Marcel Moolenaar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _SYS_UCONTEXT_H_
#define _SYS_UCONTEXT_H_
#include <sys/signal.h>
#include <machine/ucontext.h>
typedef struct __ucontext {
/*
* Keep the order of the first two fields. Also,
* keep them the first two fields in the structure.
* This way we can have a union with struct
* sigcontext and ucontext_t. This allows us to
* support them both at the same time.
* note: the union is not defined, though.
*/
sigset_t uc_sigmask;
mcontext_t uc_mcontext;
struct __ucontext *uc_link;
stack_t uc_stack;
int uc_flags;
#define UCF_SWAPPED 0x00000001 /* Used by swapcontext(3). */
int __spare__[4];
} ucontext_t;
#if defined(_KERNEL) && defined(COMPAT_FREEBSD4)
#if defined(__i386__) || defined(__alpha__)
struct ucontext4 {
sigset_t uc_sigmask;
struct mcontext4 uc_mcontext;
struct ucontext4 *uc_link;
stack_t uc_stack;
int __spare__[8];
};
#else /* __i386__ || __alpha__ */
#define ucontext4 ucontext
#endif /* __i386__ || __alpha__ */
#endif /* _KERNEL */
#ifndef _KERNEL
__BEGIN_DECLS
int getcontext(ucontext_t *);
int setcontext(const ucontext_t *);
void makecontext(ucontext_t *, void (*)(void), int, ...);
int signalcontext(ucontext_t *, int, __sighandler_t *);
int swapcontext(ucontext_t *, const ucontext_t *);
__END_DECLS
#else /* _KERNEL */
struct thread;
/* Machine-dependent functions: */
int get_mcontext(struct thread *td, mcontext_t *mcp);
int set_mcontext(struct thread *td, const mcontext_t *mcp);
#endif /* !_KERNEL */
#endif /* !_SYS_UCONTEXT_H_ */