freebsd-skq/sys/powerpc/include/pcb.h
nwhitehorn ecfb41d217 Restructure the way the copyin/copyout segment is stored to prevent a
concurrency bug. Since all SLB/SR entries were invalidated during an
exception, a decrementer exception could cause the user segment to be
invalidated during a copyin()/copyout() without a thread switch that
would cause it to be restored from the PCB, potentially causing the
operation to continue on invalid memory. This is now handled by explicit
restoration of segment 12 from the PCB on 32-bit systems and a check in
the Data Segment Exception handler on 64-bit.

While here, cause copyin()/copyout() to check whether the requested
user segment is already installed, saving some pipeline flushes, and
fix the synchronization primitives around the mtsr and slbmte
instructions to prevent accessing stale segments.

MFC after:	2 weeks
2010-10-30 23:07:30 +00:00

95 lines
3.2 KiB
C

/*-
* Copyright (C) 1995, 1996 Wolfgang Solfrank.
* Copyright (C) 1995, 1996 TooLs GmbH.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``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 TOOLS GMBH 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.
*
* $NetBSD: pcb.h,v 1.4 2000/06/04 11:57:17 tsubai Exp $
* $FreeBSD$
*/
#ifndef _MACHINE_PCB_H_
#define _MACHINE_PCB_H_
typedef register_t faultbuf[25];
struct pcb {
register_t pcb_context[20]; /* non-volatile r14-r31 */
register_t pcb_cr; /* Condition register */
register_t pcb_sp; /* stack pointer */
register_t pcb_toc; /* toc pointer */
register_t pcb_lr; /* link register */
struct pmap *pcb_pm; /* pmap of our vmspace */
faultbuf *pcb_onfault; /* For use during
copyin/copyout */
int pcb_flags;
#define PCB_FPU 1 /* Process had FPU initialized */
#define PCB_VEC 2 /* Process had Altivec initialized */
struct fpu {
double fpr[32];
double fpscr; /* FPSCR stored as double for easier access */
} pcb_fpu; /* Floating point processor */
unsigned int pcb_fpcpu; /* which CPU had our FPU
stuff. */
struct vec {
uint32_t vr[32][4];
register_t vrsave;
register_t spare[2];
register_t vscr; /* aligned at vector element 3 */
} pcb_vec __aligned(16); /* Vector processor */
unsigned int pcb_veccpu; /* which CPU had our vector
stuff. */
union {
struct {
vm_offset_t usr_segm; /* Base address */
register_t usr_vsid; /* USER_SR segment */
} aim;
struct {
register_t ctr;
register_t xer;
register_t dbcr0;
} booke;
} pcb_cpu;
};
#ifdef _KERNEL
struct trapframe;
#ifndef curpcb
extern struct pcb *curpcb;
#endif
extern struct pmap *curpm;
extern struct proc *fpuproc;
void makectx(struct trapframe *, struct pcb *);
#endif
#endif /* _MACHINE_PCB_H_ */