Logo Search packages:      
Sourcecode: linux version File versions  Download package

exceptions.c

/*
 * HW exception handling
 *
 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2008 PetaLogix
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file COPYING in the main directory of this
 * archive for more details.
 */

/*
 * This file handles the architecture-dependent parts of hardware exceptions
 */

#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kallsyms.h>
#include <linux/module.h>

#include <asm/exceptions.h>
#include <asm/entry.h>        /* For KM CPU var */
#include <linux/uaccess.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <asm/current.h>

#define MICROBLAZE_ILL_OPCODE_EXCEPTION   0x02
#define MICROBLAZE_IBUS_EXCEPTION   0x03
#define MICROBLAZE_DBUS_EXCEPTION   0x04
#define MICROBLAZE_DIV_ZERO_EXCEPTION     0x05
#define MICROBLAZE_FPU_EXCEPTION    0x06
#define MICROBLAZE_PRIVILEGED_EXCEPTION   0x07

static DEFINE_SPINLOCK(die_lock);

void die(const char *str, struct pt_regs *fp, long err)
{
      console_verbose();
      spin_lock_irq(&die_lock);
      printk(KERN_WARNING "Oops: %s, sig: %ld\n", str, err);
      show_regs(fp);
      spin_unlock_irq(&die_lock);
      /* do_exit() should take care of panic'ing from an interrupt
       * context so we don't handle it here
       */
      do_exit(err);
}

void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
{
      siginfo_t info;

      if (kernel_mode(regs)) {
            debugger(regs);
            die("Exception in kernel mode", regs, signr);
      }
      info.si_signo = signr;
      info.si_errno = 0;
      info.si_code = code;
      info.si_addr = (void __user *) addr;
      force_sig_info(signr, &info, current);
}

asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
                                          int fsr, int addr)
{
#ifdef CONFIG_MMU
      int code;
      addr = regs->pc;
#endif

#if 0
      printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x " \
                                          "ESR=%08x\n",
                  type, user_mode(regs) ? "user" : "kernel", fsr,
                  (unsigned int) regs->pc, (unsigned int) regs->esr);
#endif

      switch (type & 0x1F) {
      case MICROBLAZE_ILL_OPCODE_EXCEPTION:
            if (user_mode(regs)) {
                  pr_debug(KERN_WARNING "Illegal opcode exception " \
                                          "in user mode.\n");
                  _exception(SIGILL, regs, ILL_ILLOPC, addr);
                  return;
            }
            printk(KERN_WARNING "Illegal opcode exception " \
                                          "in kernel mode.\n");
            die("opcode exception", regs, SIGBUS);
            break;
      case MICROBLAZE_IBUS_EXCEPTION:
            if (user_mode(regs)) {
                  pr_debug(KERN_WARNING "Instruction bus error " \
                                    "exception in user mode.\n");
                  _exception(SIGBUS, regs, BUS_ADRERR, addr);
                  return;
            }
            printk(KERN_WARNING "Instruction bus error exception " \
                                          "in kernel mode.\n");
            die("bus exception", regs, SIGBUS);
            break;
      case MICROBLAZE_DBUS_EXCEPTION:
            if (user_mode(regs)) {
                  pr_debug(KERN_WARNING "Data bus error exception " \
                                          "in user mode.\n");
                  _exception(SIGBUS, regs, BUS_ADRERR, addr);
                  return;
            }
            printk(KERN_WARNING "Data bus error exception " \
                                          "in kernel mode.\n");
            die("bus exception", regs, SIGBUS);
            break;
      case MICROBLAZE_DIV_ZERO_EXCEPTION:
            if (user_mode(regs)) {
                  pr_debug(KERN_WARNING "Divide by zero exception " \
                                          "in user mode\n");
                  _exception(SIGILL, regs, FPE_INTDIV, addr);
                  return;
            }
            printk(KERN_WARNING "Divide by zero exception " \
                                          "in kernel mode.\n");
            die("Divide by exception", regs, SIGBUS);
            break;
      case MICROBLAZE_FPU_EXCEPTION:
            pr_debug(KERN_WARNING "FPU exception\n");
            /* IEEE FP exception */
            /* I removed fsr variable and use code var for storing fsr */
            if (fsr & FSR_IO)
                  fsr = FPE_FLTINV;
            else if (fsr & FSR_OF)
                  fsr = FPE_FLTOVF;
            else if (fsr & FSR_UF)
                  fsr = FPE_FLTUND;
            else if (fsr & FSR_DZ)
                  fsr = FPE_FLTDIV;
            else if (fsr & FSR_DO)
                  fsr = FPE_FLTRES;
            _exception(SIGFPE, regs, fsr, addr);
            break;

#ifdef CONFIG_MMU
      case MICROBLAZE_PRIVILEGED_EXCEPTION:
            pr_debug(KERN_WARNING "Privileged exception\n");
            /* "brk r0,r0" - used as debug breakpoint */
            if (get_user(code, (unsigned long *)regs->pc) == 0
                  && code == 0x980c0000) {
                  _exception(SIGTRAP, regs, TRAP_BRKPT, addr);
            } else {
                  _exception(SIGILL, regs, ILL_PRVOPC, addr);
            }
            break;
#endif
      default:
      /* FIXME what to do in unexpected exception */
            printk(KERN_WARNING "Unexpected exception %02x "
                  "PC=%08x in %s mode\n", type, (unsigned int) addr,
                  kernel_mode(regs) ? "kernel" : "user");
      }
      return;
}

Generated by  Doxygen 1.6.0   Back to index