Minix1.5/kernel/exception.c

/* This file contains a simple exception handler.  Exceptions in user
 * processes are converted to signals.  Exceptions in the kernel, MM and
 * FS cause a panic.
 */

#include "kernel.h"
#include <signal.h>
#include "proc.h"

/*==========================================================================*
 *				exception				    *
 *==========================================================================*/
PUBLIC void exception(vec_nr)
unsigned vec_nr;
{
/* An exception or unexpected interrupt has occurred. */

  struct ex_s {
	char *msg;
	int signum;
	int minprocessor;
  };
  static struct ex_s ex_data[] = {
	"Divide error", SIGFPE, 86,
	"Debug exception", SIGTRAP, 86,		/* overidden by debugger */
	"Nonmaskable interrupt", SIGBUS, 86,	/* needs separate handler */
	"Breakpoint", SIGEMT, 86,		/* overidden by debugger */
	"Overflow", SIGFPE, 86,
	"Bounds check", SIGFPE, 186,
	"Invalid opcode", SIGILL, 186,
	"Coprocessor not available", SIGFPE, 186,
	"Double fault", SIGBUS, 286,
	"Copressor segment overrun", SIGSEGV, 286,
	"Invalid TSS", SIGSEGV, 286,
	"Segment not present", SIGSEGV, 286,
	"Stack exception", SIGSEGV, 286,	/* STACK_FAULT already used */
	"General protection", SIGSEGV, 286,
	"Page fault", SIGSEGV, 386,		/* not close */
	NIL_PTR, SIGILL, 0,			/* probably software trap */
	"Coprocessor error", SIGFPE, 386,
	"Unexpected interrupt along vector >= 17", SIGILL, 0,
  };
  register struct ex_s *ep;

  ep = &ex_data[vec_nr];

  if (k_reenter == 0 && isuserp(proc_ptr)) {
	unlock();		/* this is protected like sys_call() */
	cause_sig(proc_number(proc_ptr), ep->signum);
	return;
  }

  /* This is not supposed to happen. */
  if (ep->msg == NIL_PTR || processor < ep->minprocessor)
	printf("\r\nIntel-reserved exception %d\r\n", vec_nr);
  else
	printf("\r\n%s\r\n", ep->msg);
  printf("process number %d, pc = 0x%04x:0x%08lx\r\n",
	 proc_number(proc_ptr),
	 (unsigned) proc_ptr->p_reg.cs,
  	 (unsigned long) proc_ptr->p_reg.pc);
  panic("exception in kernel, mm or fs", NO_NUM);
}