arch/mips/kernel/fpe.c

   1 /*
   2  * The real floating point exception handler.  While it doesn't really
   3  * make sense to have this in a module, it makes debugging of this code
   4  * in the kernel space a lot easier.  So far this handler in the released
   5  * kernel source is just a dummy.
   6  *
   7  * Copyright (C) 1997 Ralf Baechle
   8  *
   9  * $Id: fpe.c,v 1.4 1999/05/01 22:40:35 ralf Exp $
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/sched.h>
  14 #include <linux/signal.h>
  15 #include <linux/smp.h>
  16 #include <linux/smp_lock.h>
  17
  18 #include <asm/branch.h>
  19 #include <asm/ptrace.h>
  20
  21 MODULE_AUTHOR("Ralf Baechle <ralf@gnu.org>");
  22 MODULE_DESCRIPTION("Experimental floating point exception handler");
  23 MODULE_SUPPORTED_DEVICE("MIPS FPU");
  24
  25 static void do_fpe(struct pt_regs *regs, unsigned int fcr31)
  26 {
  27         lock_kernel();
  28 #ifdef CONF_DEBUG_EXCEPTIONS
  29         show_regs(regs);
  30 #endif
  31         printk("Caught floating exception at epc == %08lx, fcr31 == %08x\n",
  32                regs->cp0_epc, fcr31);
  33         if (compute_return_epc(regs))
  34                 goto out;
  35         force_sig(SIGFPE, current);
  36 out:
  37         unlock_kernel();
  38 }
  39
  40 /*
  41  * For easier experimentation we never increment/decrement
  42  * the module usable counter.
  43  */
  44 int register_fpe(void (*handler)(struct pt_regs *regs, unsigned int fcr31));
  45 int unregister_fpe(void (*handler)(struct pt_regs *regs, unsigned int fcr31));
  46
  47 int init_module(void)
  48 {
  49         return register_fpe(do_fpe);
  50 }
  51
  52 void cleanup_module(void)
  53 {
  54         unregister_fpe(do_fpe);
  55 }