sys/platform/pc64/amd64/exception.c

   1
   2 /*
   3  * Copyright (c) 2006 The DragonFly Project.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to The DragonFly Project
   6  * by Matthew Dillon <dillon@backplane.com>
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  * 3. Neither the name of The DragonFly Project nor the names of its
  19  *    contributors may be used to endorse or promote products derived
  20  *    from this software without specific, prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  * $DragonFly: src/sys/platform/pc64/amd64/exception.c,v 1.2 2007/09/24 03:24:45 yanyh Exp $
  36  */
  37
  38 #include "opt_ddb.h"
  39 #include <sys/types.h>
  40 #include <sys/systm.h>
  41 #include <sys/reboot.h>
  42 #include <sys/kernel.h>
  43 #include <sys/kthread.h>
  44 #include <sys/reboot.h>
  45 #include <sys/signal.h>
  46 #include <ddb/ddb.h>
  47
  48 #include <sys/thread2.h>
  49
  50 #include <machine/trap.h>
  51 #include <machine/md_var.h>
  52 #include <machine/segments.h>
  53 #include <machine/cpu.h>
  54
  55 int _ucodesel = LSEL(LUCODE_SEL, SEL_UPL);
  56 int _udatasel = LSEL(LUDATA_SEL, SEL_UPL);
  57
  58 static void exc_segfault(int signo, siginfo_t *info, void *ctx);
  59 #ifdef DDB
  60 static void exc_debugger(int signo, siginfo_t *info, void *ctx);
  61 #endif
  62
  63 /*
  64  * IPIs are 'fast' interrupts, so we deal with them directly from our
  65  * signal handler.
  66  */
  67
  68 #ifdef SMP
  69
  70 static
  71 void
  72 ipisig(int nada, siginfo_t *info, void *ctxp)
  73 {
  74         ++mycpu->gd_intr_nesting_level;
  75         if (curthread->td_pri < TDPRI_CRIT) {
  76                 curthread->td_pri += TDPRI_CRIT;
  77                 lwkt_process_ipiq();
  78                 curthread->td_pri -= TDPRI_CRIT;
  79         } else {
  80                 need_ipiq();
  81         }
  82         --mycpu->gd_intr_nesting_level;
  83 }
  84
  85 #endif
  86
  87 void
  88 init_exceptions(void)
  89 {
  90 }
  91
  92 /*
  93  * This function handles a segmentation fault.
  94  *
  95  * XXX We assume that trapframe is a subset of ucontext.  It is as of
  96  *     this writing.
  97  */
  98 static void
  99 exc_segfault(int signo, siginfo_t *info, void *ctxp)
 100 {
 101         ucontext_t *ctx = ctxp;
 102
 103 #if 0
 104         kprintf("CAUGHT SEGFAULT EIP %08x ERR %08x TRAPNO %d err %d\n",
 105                 ctx->uc_mcontext.mc_eip,
 106                 ctx->uc_mcontext.mc_err,
 107                 ctx->uc_mcontext.mc_trapno & 0xFFFF,
 108                 ctx->uc_mcontext.mc_trapno >> 16);
 109         kern_trap((struct trapframe *)&ctx->uc_mcontext.mc_gs);
 110 #endif
 111         splz();
 112 }
 113
 114 #ifdef DDB
 115
 116 static void
 117 exc_debugger(int signo, siginfo_t *info, void *ctx)
 118 {
 119         Debugger("interrupt from console");
 120 }
 121
 122 #endif