freebsd-dev/sys/i386/include/pcb_ext.h
John Baldwin f726a87319 Explicitly switch to the new TSS by updating the current CPU's TSS selector
and reloading it in i386_extend_pcb() rather than trying to force a context
switch to reload the TSS via the TDF_NEEDRESCHED flag.  Optimizations to
avoid calling cpu_switch() when the new thread was identical to the old
thread defeated the attempt to force a TSS reload.  Explicitly loading the
new TSS is what we really want to do anyway.

PR:		i386/84842
Reported by:	Alexander Best arundel at h3c dot de
MFC after:	1 week
Reviewed by:	bde (mostly)
2005-09-15 17:30:08 +00:00

54 lines
1.9 KiB
C

/*-
* Copyright (c) 1997 Jonathan Lemon
* 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.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 _I386_PCB_EXT_H_
#define _I386_PCB_EXT_H_
/*
* Extension to the 386 process control block
*/
#include <machine/tss.h>
#include <machine/vm86.h>
#include <machine/segments.h>
struct pcb_ext {
struct segment_descriptor ext_tssd; /* tss descriptor */
struct i386tss ext_tss; /* per-process i386tss */
caddr_t ext_iomap; /* i/o permission bitmap */
struct vm86_kernel ext_vm86; /* vm86 area */
};
#ifdef _KERNEL
extern int private_tss;
int i386_extend_pcb(struct thread *);
#endif
#endif /* _I386_PCB_EXT_H_ */