590 lines
15 KiB
C
590 lines
15 KiB
C
/*-
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* the University of Utah, and William Jolitz.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
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* $Id: trap.c,v 1.5 1993/11/01 11:51:29 chmr Exp $
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*/
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/*
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* 386 Trap and System call handleing
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*/
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#include "npx.h"
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#include "machine/cpu.h"
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#include "machine/psl.h"
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#include "machine/reg.h"
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#include "param.h"
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#include "systm.h"
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#include "proc.h"
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#include "user.h"
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#include "acct.h"
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#include "kernel.h"
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#ifdef KTRACE
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#include "ktrace.h"
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#endif
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#include "vm/vm_param.h"
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#include "vm/pmap.h"
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#include "vm/vm_map.h"
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#include "sys/vmmeter.h"
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#include "machine/trap.h"
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#ifdef __GNUC__
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/*
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* The "r" contraint could be "rm" except for fatal bugs in gas. As usual,
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* we omit the size from the mov instruction to avoid nonfatal bugs in gas.
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*/
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#define read_gs() ({ u_short gs; __asm("mov %%gs,%0" : "=r" (gs)); gs; })
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#define write_gs(gs) __asm("mov %0,%%gs" : : "r" ((u_short) gs))
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#else /* not __GNUC__ */
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u_short read_gs __P((void));
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void write_gs __P((/* promoted u_short */ int gs));
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#endif /* __GNUC__ */
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struct sysent sysent[];
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int nsysent;
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int dostacklimits;
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unsigned rcr2();
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extern short cpl;
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/*
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* trap(frame):
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* Exception, fault, and trap interface to BSD kernel. This
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* common code is called from assembly language IDT gate entry
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* routines that prepare a suitable stack frame, and restore this
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* frame after the exception has been processed. Note that the
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* effect is as if the arguments were passed call by reference.
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*/
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/*ARGSUSED*/
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trap(frame)
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struct trapframe frame;
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{
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register int i;
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register struct proc *p = curproc;
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struct timeval syst;
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int ucode, type, code, eva;
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frame.tf_eflags &= ~PSL_NT; /* clear nested trap XXX */
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type = frame.tf_trapno;
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#include "ddb.h"
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#if NDDB > 0
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if (curpcb && curpcb->pcb_onfault) {
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if (frame.tf_trapno == T_BPTFLT
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|| frame.tf_trapno == T_TRCTRAP)
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if (kdb_trap (type, 0, &frame))
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return;
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}
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#endif
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/*pg("trap type %d code = %x eip = %x cs = %x eva = %x esp %x",
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frame.tf_trapno, frame.tf_err, frame.tf_eip,
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frame.tf_cs, rcr2(), frame.tf_esp);*/
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if(curpcb == 0 || curproc == 0) goto we_re_toast;
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if (curpcb->pcb_onfault && frame.tf_trapno != T_PAGEFLT) {
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extern int _udatasel;
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if (read_gs() != (u_short) _udatasel)
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/*
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* Some user has corrupted %gs but we depend on it in
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* copyout() etc. Fix it up and retry.
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*
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* (We don't preserve %fs or %gs, so users can change
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* them to either _ucodesel, _udatasel or a not-present
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* selector, possibly ORed with 0 to 3, making them
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* volatile for other users. Not preserving them saves
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* time and doesn't lose functionality or open security
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* holes.)
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*/
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write_gs(_udatasel);
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else
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copyfault:
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frame.tf_eip = (int)curpcb->pcb_onfault;
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return;
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}
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syst = p->p_stime;
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if (ISPL(frame.tf_cs) == SEL_UPL) {
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type |= T_USER;
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p->p_regs = (int *)&frame;
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curpcb->pcb_flags |= FM_TRAP; /* used by sendsig */
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}
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ucode=0;
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eva = rcr2();
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code = frame.tf_err;
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switch (type) {
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default:
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we_re_toast:
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#ifdef KDB
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if (kdb_trap(&psl))
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return;
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#endif
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#if NDDB > 0
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if (kdb_trap (type, 0, &frame))
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return;
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#endif
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printf("trap type %d code = %x eip = %x cs = %x eflags = %x ",
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frame.tf_trapno, frame.tf_err, frame.tf_eip,
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frame.tf_cs, frame.tf_eflags);
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eva = rcr2();
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printf("cr2 %x cpl %x\n", eva, cpl);
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/* type &= ~T_USER; */ /* XXX what the hell is this */
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panic("trap");
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/*NOTREACHED*/
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case T_SEGNPFLT|T_USER:
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case T_STKFLT|T_USER:
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case T_PROTFLT|T_USER: /* protection fault */
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ucode = code + BUS_SEGM_FAULT ;
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i = SIGBUS;
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break;
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case T_PRIVINFLT|T_USER: /* privileged instruction fault */
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case T_RESADFLT|T_USER: /* reserved addressing fault */
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case T_RESOPFLT|T_USER: /* reserved operand fault */
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case T_FPOPFLT|T_USER: /* coprocessor operand fault */
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ucode = type &~ T_USER;
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i = SIGILL;
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break;
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case T_ASTFLT|T_USER: /* Allow process switch */
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astoff();
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cnt.v_soft++;
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if ((p->p_flag & SOWEUPC) && p->p_stats->p_prof.pr_scale) {
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addupc(frame.tf_eip, &p->p_stats->p_prof, 1);
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p->p_flag &= ~SOWEUPC;
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}
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goto out;
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case T_DNA|T_USER:
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#if NNPX > 0
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/* if a transparent fault (due to context switch "late") */
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if (npxdna()) return;
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#endif /* NNPX > 0 */
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#ifdef MATH_EMULATE
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i = math_emulate(&frame);
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if (i == 0) return;
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#else /* MATH_EMULTATE */
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panic("trap: math emulation necessary!");
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#endif /* MATH_EMULTATE */
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ucode = FPE_FPU_NP_TRAP;
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break;
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case T_BOUND|T_USER:
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ucode = FPE_SUBRNG_TRAP;
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i = SIGFPE;
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break;
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case T_OFLOW|T_USER:
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ucode = FPE_INTOVF_TRAP;
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i = SIGFPE;
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break;
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case T_DIVIDE|T_USER:
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ucode = FPE_INTDIV_TRAP;
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i = SIGFPE;
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break;
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case T_ARITHTRAP|T_USER:
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ucode = code;
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i = SIGFPE;
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break;
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case T_PAGEFLT: /* allow page faults in kernel mode */
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#if 0
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/* XXX - check only applies to 386's and 486's with WP off */
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if (code & PGEX_P) goto we_re_toast;
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#endif
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/* fall into */
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case T_PAGEFLT|T_USER: /* page fault */
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{
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register vm_offset_t va;
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register struct vmspace *vm = p->p_vmspace;
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register vm_map_t map;
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int rv;
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vm_prot_t ftype;
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extern vm_map_t kernel_map;
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unsigned nss,v;
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va = trunc_page((vm_offset_t)eva);
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/*
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* It is only a kernel address space fault iff:
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* 1. (type & T_USER) == 0 and
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* 2. pcb_onfault not set or
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* 3. pcb_onfault set but supervisor space fault
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* The last can occur during an exec() copyin where the
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* argument space is lazy-allocated.
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*/
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if (type == T_PAGEFLT && va >= KERNBASE)
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map = kernel_map;
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else
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map = &vm->vm_map;
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if (code & PGEX_W)
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ftype = VM_PROT_READ | VM_PROT_WRITE;
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else
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ftype = VM_PROT_READ;
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#ifdef DEBUG
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if (map == kernel_map && va == 0) {
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printf("trap: bad kernel access at %x\n", va);
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goto we_re_toast;
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}
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#endif
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/*
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* XXX: rude hack to make stack limits "work"
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*/
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nss = 0;
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if ((caddr_t)va >= vm->vm_maxsaddr
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&& (caddr_t)va < (caddr_t)VM_MAXUSER_ADDRESS
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&& map != kernel_map
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&& dostacklimits) {
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nss = clrnd(btoc((unsigned)vm->vm_maxsaddr
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+ MAXSSIZ - (unsigned)va));
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if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
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/*pg("trap rlimit %d, maxsaddr %x va %x ", nss, vm->vm_maxsaddr, va);*/
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rv = KERN_FAILURE;
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goto nogo;
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}
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}
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/* check if page table is mapped, if not, fault it first */
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#define pde_v(v) (PTD[((v)>>PD_SHIFT)&1023].pd_v)
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if (!pde_v(va)) {
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v = trunc_page(vtopte(va));
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rv = vm_fault(map, v, ftype, FALSE);
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if (rv != KERN_SUCCESS) goto nogo;
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/* check if page table fault, increment wiring */
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vm_map_pageable(map, v, round_page(v+1), FALSE);
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} else v=0;
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rv = vm_fault(map, va, ftype, FALSE);
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if (rv == KERN_SUCCESS) {
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/*
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* XXX: continuation of rude stack hack
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*/
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if (nss > vm->vm_ssize)
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vm->vm_ssize = nss;
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va = trunc_page(vtopte(va));
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/* for page table, increment wiring
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as long as not a page table fault as well */
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if (!v && type != T_PAGEFLT)
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vm_map_pageable(map, va, round_page(va+1), FALSE);
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if (type == T_PAGEFLT)
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return;
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goto out;
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}
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nogo:
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if (type == T_PAGEFLT) {
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if (curpcb->pcb_onfault)
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goto copyfault;
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printf("vm_fault(%x, %x, %x, 0) -> %x\n",
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map, va, ftype, rv);
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printf(" type %x, code %x\n",
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type, code);
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goto we_re_toast;
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}
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i = (rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV;
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break;
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}
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#if NDDB == 0
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case T_TRCTRAP: /* trace trap -- someone single stepping lcall's */
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frame.tf_eflags &= ~PSL_T;
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/* Q: how do we turn it on again? */
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return;
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#endif
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case T_BPTFLT|T_USER: /* bpt instruction fault */
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case T_TRCTRAP|T_USER: /* trace trap */
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frame.tf_eflags &= ~PSL_T;
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i = SIGTRAP;
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break;
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#include "isa.h"
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#if NISA > 0
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case T_NMI:
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case T_NMI|T_USER:
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#if NDDB > 0
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/* NMI can be hooked up to a pushbutton for debugging */
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printf ("NMI ... going to debugger\n");
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if (kdb_trap (type, 0, &frame))
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return;
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#endif
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/* machine/parity/power fail/"kitchen sink" faults */
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if(isa_nmi(code) == 0) return;
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else goto we_re_toast;
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#endif
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}
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trapsignal(p, i, ucode);
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if ((type & T_USER) == 0)
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return;
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out:
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while (i = CURSIG(p))
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psig(i);
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p->p_pri = p->p_usrpri;
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if (want_resched) {
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int s;
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/*
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* Since we are curproc, clock will normally just change
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* our priority without moving us from one queue to another
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* (since the running process is not on a queue.)
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* If that happened after we setrq ourselves but before we
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* swtch()'ed, we might not be on the queue indicated by
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* our priority.
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*/
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s = splclock();
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setrq(p);
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p->p_stats->p_ru.ru_nivcsw++;
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swtch();
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splx(s);
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while (i = CURSIG(p))
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psig(i);
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}
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if (p->p_stats->p_prof.pr_scale) {
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int ticks;
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struct timeval *tv = &p->p_stime;
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ticks = ((tv->tv_sec - syst.tv_sec) * 1000 +
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(tv->tv_usec - syst.tv_usec) / 1000) / (tick / 1000);
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if (ticks) {
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#ifdef PROFTIMER
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extern int profscale;
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addupc(frame.tf_eip, &p->p_stats->p_prof,
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ticks * profscale);
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#else
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addupc(frame.tf_eip, &p->p_stats->p_prof, ticks);
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#endif
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}
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}
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curpri = p->p_pri;
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curpcb->pcb_flags &= ~FM_TRAP; /* used by sendsig */
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}
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/*
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* Compensate for 386 brain damage (missing URKR).
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* This is a little simpler than the pagefault handler in trap() because
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* it the page tables have already been faulted in and high addresses
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* are thrown out early for other reasons.
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*/
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int trapwrite(addr)
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unsigned addr;
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{
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unsigned nss;
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struct proc *p;
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vm_offset_t va;
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struct vmspace *vm;
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va = trunc_page((vm_offset_t)addr);
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/*
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* XXX - MAX is END. Changed > to >= for temp. fix.
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*/
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if (va >= VM_MAXUSER_ADDRESS)
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return (1);
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/*
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* XXX: rude stack hack adapted from trap().
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*/
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nss = 0;
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p = curproc;
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vm = p->p_vmspace;
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if ((caddr_t)va >= vm->vm_maxsaddr && dostacklimits) {
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nss = clrnd(btoc((unsigned)vm->vm_maxsaddr + MAXSSIZ
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- (unsigned)va));
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if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
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return (1);
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}
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if (vm_fault(&vm->vm_map, va, VM_PROT_READ | VM_PROT_WRITE, FALSE)
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!= KERN_SUCCESS)
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return (1);
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/*
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* XXX: continuation of rude stack hack
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*/
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if (nss > vm->vm_ssize)
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vm->vm_ssize = nss;
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return (0);
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}
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/*
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* syscall(frame):
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* System call request from POSIX system call gate interface to kernel.
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* Like trap(), argument is call by reference.
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*/
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/*ARGSUSED*/
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syscall(frame)
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volatile struct syscframe frame;
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{
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register int *locr0 = ((int *)&frame);
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register caddr_t params;
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register int i;
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register struct sysent *callp;
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register struct proc *p = curproc;
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struct timeval syst;
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int error, opc;
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int args[8], rval[2];
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int code;
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#ifdef lint
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r0 = 0; r0 = r0; r1 = 0; r1 = r1;
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#endif
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syst = p->p_stime;
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if (ISPL(frame.sf_cs) != SEL_UPL)
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panic("syscall");
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code = frame.sf_eax;
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curpcb->pcb_flags &= ~FM_TRAP; /* used by sendsig */
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p->p_regs = (int *)&frame;
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params = (caddr_t)frame.sf_esp + sizeof (int) ;
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/*
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* Reconstruct pc, assuming lcall $X,y is 7 bytes, as it is always.
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*/
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opc = frame.sf_eip - 7;
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callp = (code >= nsysent) ? &sysent[63] : &sysent[code];
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if (callp == sysent) {
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i = fuword(params);
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params += sizeof (int);
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callp = (code >= nsysent) ? &sysent[63] : &sysent[code];
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}
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if ((i = callp->sy_narg * sizeof (int)) &&
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(error = copyin(params, (caddr_t)args, (u_int)i))) {
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frame.sf_eax = error;
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frame.sf_eflags |= PSL_C; /* carry bit */
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#ifdef KTRACE
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if (KTRPOINT(p, KTR_SYSCALL))
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ktrsyscall(p->p_tracep, code, callp->sy_narg, &args);
|
|
#endif
|
|
goto done;
|
|
}
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(p, KTR_SYSCALL))
|
|
ktrsyscall(p->p_tracep, code, callp->sy_narg, &args);
|
|
#endif
|
|
rval[0] = 0;
|
|
rval[1] = frame.sf_edx;
|
|
/*pg("%d. s %d\n", p->p_pid, code);*/
|
|
error = (*callp->sy_call)(p, args, rval);
|
|
if (error == ERESTART)
|
|
frame.sf_eip = opc;
|
|
else if (error != EJUSTRETURN) {
|
|
if (error) {
|
|
/*pg("error %d", error);*/
|
|
frame.sf_eax = error;
|
|
frame.sf_eflags |= PSL_C; /* carry bit */
|
|
} else {
|
|
frame.sf_eax = rval[0];
|
|
frame.sf_edx = rval[1];
|
|
frame.sf_eflags &= ~PSL_C; /* carry bit */
|
|
}
|
|
}
|
|
/* else if (error == EJUSTRETURN) */
|
|
/* nothing to do */
|
|
done:
|
|
/*
|
|
* Reinitialize proc pointer `p' as it may be different
|
|
* if this is a child returning from fork syscall.
|
|
*/
|
|
p = curproc;
|
|
while (i = CURSIG(p))
|
|
psig(i);
|
|
p->p_pri = p->p_usrpri;
|
|
if (want_resched) {
|
|
int s;
|
|
/*
|
|
* Since we are curproc, clock will normally just change
|
|
* our priority without moving us from one queue to another
|
|
* (since the running process is not on a queue.)
|
|
* If that happened after we setrq ourselves but before we
|
|
* swtch()'ed, we might not be on the queue indicated by
|
|
* our priority.
|
|
*/
|
|
s = splclock();
|
|
setrq(p);
|
|
p->p_stats->p_ru.ru_nivcsw++;
|
|
swtch();
|
|
splx(s);
|
|
while (i = CURSIG(p))
|
|
psig(i);
|
|
}
|
|
if (p->p_stats->p_prof.pr_scale) {
|
|
int ticks;
|
|
struct timeval *tv = &p->p_stime;
|
|
|
|
ticks = ((tv->tv_sec - syst.tv_sec) * 1000 +
|
|
(tv->tv_usec - syst.tv_usec) / 1000) / (tick / 1000);
|
|
if (ticks) {
|
|
#ifdef PROFTIMER
|
|
extern int profscale;
|
|
addupc(frame.sf_eip, &p->p_stats->p_prof,
|
|
ticks * profscale);
|
|
#else
|
|
addupc(frame.sf_eip, &p->p_stats->p_prof, ticks);
|
|
#endif
|
|
}
|
|
}
|
|
curpri = p->p_pri;
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(p, KTR_SYSRET))
|
|
ktrsysret(p->p_tracep, code, error, rval[0]);
|
|
#endif
|
|
#ifdef DIAGNOSTICx
|
|
{ extern int _udatasel, _ucodesel;
|
|
if (frame.sf_ss != _udatasel)
|
|
printf("ss %x call %d\n", frame.sf_ss, code);
|
|
if ((frame.sf_cs&0xffff) != _ucodesel)
|
|
printf("cs %x call %d\n", frame.sf_cs, code);
|
|
if (frame.sf_eip > VM_MAXUSER_ADDRESS) {
|
|
printf("eip %x call %d\n", frame.sf_eip, code);
|
|
frame.sf_eip = 0;
|
|
}
|
|
}
|
|
#endif
|
|
}
|