arch/nios2nommu/kernel/traps.c

   1 /*
   2  * arch/niosnommu/kernel/traps.c
   3  *
   4  * Copyright 2004 Microtronix Datacom Ltd.
   5  * Copyright 2001 Vic Phillips
   6  * Copyright 1995 David S. Miller (davem@caip.rutgers.edu)
   7  *
   8  * hacked from:
   9  *
  10  * arch/sparcnommu/kernel/traps.c
  11  *
  12  * All rights reserved.
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful, but
  20  * WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  22  * NON INFRINGEMENT.  See the GNU General Public License for more
  23  * details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program; if not, write to the Free Software
  27  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  28  *
  29  */
  30
  31 #include <linux/sched.h>  /* for jiffies */
  32 #include <linux/kernel.h>
  33 #include <linux/signal.h>
  34 #include <linux/module.h>
  35
  36 #include <asm/delay.h>
  37 #include <asm/system.h>
  38 #include <asm/ptrace.h>
  39 #include <asm/page.h>
  40 #include <asm/pgtable.h>
  41 #include <asm/unistd.h>
  42
  43 #include <asm/nios.h>
  44
  45 /* #define TRAP_DEBUG */
  46
  47 #if 0
  48 void dumpit(unsigned long l1, unsigned long l2)
  49 {
  50         printk("0x%08x l1 0x%08x l2\n");
  51         while(1);
  52 }
  53
  54 struct trap_trace_entry {
  55         unsigned long pc;
  56         unsigned long type;
  57 };
  58
  59 int trap_curbuf = 0;
  60 struct trap_trace_entry trapbuf[1024];
  61
  62 void syscall_trace_entry(struct pt_regs *regs)
  63 {
  64         printk("%s[%d]: ", current->comm, current->pid);
  65         printk("scall<%d> (could be %d)\n", (int) regs->r3,
  66                (int) regs->r4);
  67 }
  68
  69 void syscall_trace_exit(struct pt_regs *regs)
  70 {
  71 }
  72 #endif
  73
  74 /*
  75  * The architecture-independent backtrace generator
  76  */
  77 void dump_stack(void)
  78 {
  79         unsigned long stack;
  80
  81         show_stack(current, &stack);
  82 }
  83
  84 EXPORT_SYMBOL(dump_stack);
  85
  86 /*
  87  * The show_stack is an external API which we do not use ourselves.
  88  * The oops is printed in die_if_kernel.
  89  */
  90
  91 int kstack_depth_to_print = 48;
  92
  93 void show_stack(struct task_struct *task, unsigned long *stack)
  94 {
  95         unsigned long *endstack, addr;
  96         extern char _start, _etext;
  97         int i;
  98
  99         if (!stack) {
 100                 if (task)
 101                         stack = (unsigned long *)task->thread.ksp;
 102                 else
 103                         stack = (unsigned long *)&stack;
 104         }
 105
 106         addr = (unsigned long) stack;
 107         endstack = (unsigned long *) PAGE_ALIGN(addr);
 108
 109         printk(KERN_EMERG "Stack from %08lx:", (unsigned long)stack);
 110         for (i = 0; i < kstack_depth_to_print; i++) {
 111                 if (stack + 1 > endstack)
 112                         break;
 113                 if (i % 8 == 0)
 114                         printk(KERN_EMERG "\n       ");
 115                 printk(KERN_EMERG " %08lx", *stack++);
 116         }
 117
 118         printk(KERN_EMERG "\nCall Trace:");
 119         i = 0;
 120         while (stack + 1 <= endstack) {
 121                 addr = *stack++;
 122                 /*
 123                  * If the address is either in the text segment of the
 124                  * kernel, or in the region which contains vmalloc'ed
 125                  * memory, it *may* be the address of a calling
 126                  * routine; if so, print it so that someone tracing
 127                  * down the cause of the crash will be able to figure
 128                  * out the call path that was taken.
 129                  */
 130                 if (((addr >= (unsigned long) &_start) &&
 131                      (addr <= (unsigned long) &_etext))) {
 132                         if (i % 4 == 0)
 133                                 printk(KERN_EMERG "\n       ");
 134                         printk(KERN_EMERG " [<%08lx>]", addr);
 135                         i++;
 136                 }
 137         }
 138         printk(KERN_EMERG "\n");
 139 }
 140
 141 void die_if_kernel(char *str, struct pt_regs *pregs)
 142 {
 143         unsigned long pc;
 144
 145         pc = pregs->ra;
 146         printk("0x%08lx\n trapped to die_if_kernel\n",pregs->ra);
 147         show_regs(pregs);
 148         if(pregs->status_extension & PS_S)
 149                 do_exit(SIGKILL);
 150         do_exit(SIGSEGV);
 151 }
 152
 153 void do_hw_interrupt(unsigned long type, unsigned long psr, unsigned long pc)
 154 {
 155         if(type < 0x10) {
 156                 printk("Unimplemented Nios2 TRAP, type = %02lx\n", type);
 157                 die_if_kernel("Whee... Hello Mr. Penguin", current->thread.kregs);
 158         }
 159 }
 160
 161 #if 0
 162 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long psr)
 163 {
 164 #ifdef TRAP_DEBUG
 165         printk("Watchpoint detected at PC %08lx PSR %08lx\n", pc, psr);
 166 #endif
 167         if(psr & PSR_SUPERVISOR)
 168                 panic("Tell me what a watchpoint trap is, and I'll then deal "
 169                       "with such a beast...");
 170 }
 171 #endif
 172
 173 void trap_init(void)
 174 {
 175 #ifdef DEBUG
 176         printk("trap_init reached\n");
 177 #endif
 178 }