arch/cris/kernel/traps.c

   1 /* $Id: traps.c,v 1.9 2004/05/11 12:28:26 starvik Exp $
   2  *
   3  *  linux/arch/cris/traps.c
   4  *
   5  *  Here we handle the break vectors not used by the system call
   6  *  mechanism, as well as some general stack/register dumping
   7  *  things.
   8  *
   9  *  Copyright (C) 2000-2002 Axis Communications AB
  10  *
  11  *  Authors:   Bjorn Wesen
  12  *             Hans-Peter Nilsson
  13  *
  14  */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <asm/pgtable.h>
  19 #include <asm/uaccess.h>
  20
  21 static int kstack_depth_to_print = 24;
  22
  23 void show_trace(unsigned long * stack)
  24 {
  25         unsigned long addr, module_start, module_end;
  26         extern char _stext, _etext;
  27         int i;
  28
  29         printk("\nCall Trace: ");
  30
  31         i = 1;
  32         module_start = VMALLOC_START;
  33         module_end = VMALLOC_END;
  34
  35         while (((long) stack & (THREAD_SIZE-1)) != 0) {
  36                 if (__get_user (addr, stack)) {
  37                         /* This message matches "failing address" marked
  38                            s390 in ksymoops, so lines containing it will
  39                            not be filtered out by ksymoops.  */
  40                         printk ("Failing address 0x%lx\n", (unsigned long)stack);
  41                         break;
  42                 }
  43                 stack++;
  44
  45                 /*
  46                  * If the address is either in the text segment of the
  47                  * kernel, or in the region which contains vmalloc'ed
  48                  * memory, it *may* be the address of a calling
  49                  * routine; if so, print it so that someone tracing
  50                  * down the cause of the crash will be able to figure
  51                  * out the call path that was taken.
  52                  */
  53                 if (((addr >= (unsigned long) &_stext) &&
  54                      (addr <= (unsigned long) &_etext)) ||
  55                     ((addr >= module_start) && (addr <= module_end))) {
  56                         if (i && ((i % 8) == 0))
  57                                 printk("\n       ");
  58                         printk("[<%08lx>] ", addr);
  59                         i++;
  60                 }
  61         }
  62 }
  63
  64 /*
  65  * These constants are for searching for possible module text
  66  * segments. MODULE_RANGE is a guess of how much space is likely
  67  * to be vmalloced.
  68  */
  69
  70 #define MODULE_RANGE (8*1024*1024)
  71
  72 /*
  73  * The output (format, strings and order) is adjusted to be usable with
  74  * ksymoops-2.4.1 with some necessary CRIS-specific patches.  Please don't
  75  * change it unless you're serious about adjusting ksymoops and syncing
  76  * with the ksymoops maintainer.
  77  */
  78
  79 void
  80 show_stack(struct task_struct *task, unsigned long *sp)
  81 {
  82         unsigned long *stack, addr;
  83         int i;
  84
  85         /*
  86          * debugging aid: "show_stack(NULL);" prints a
  87          * back trace.
  88          */
  89
  90         if(sp == NULL) {
  91                 if (task)
  92                         sp = (unsigned long*)task->thread.ksp;
  93                 else
  94                         sp = (unsigned long*)rdsp();
  95         }
  96
  97         stack = sp;
  98
  99         printk("\nStack from %08lx:\n       ", (unsigned long)stack);
 100         for(i = 0; i < kstack_depth_to_print; i++) {
 101                 if (((long) stack & (THREAD_SIZE-1)) == 0)
 102                         break;
 103                 if (i && ((i % 8) == 0))
 104                         printk("\n       ");
 105                 if (__get_user (addr, stack)) {
 106                         /* This message matches "failing address" marked
 107                            s390 in ksymoops, so lines containing it will
 108                            not be filtered out by ksymoops.  */
 109                         printk ("Failing address 0x%lx\n", (unsigned long)stack);
 110                         break;
 111                 }
 112                 stack++;
 113                 printk("%08lx ", addr);
 114         }
 115         show_trace(sp);
 116 }
 117
 118 #if 0
 119 /* displays a short stack trace */
 120
 121 int
 122 show_stack()
 123 {
 124         unsigned long *sp = (unsigned long *)rdusp();
 125         int i;
 126         printk("Stack dump [0x%08lx]:\n", (unsigned long)sp);
 127         for(i = 0; i < 16; i++)
 128                 printk("sp + %d: 0x%08lx\n", i*4, sp[i]);
 129         return 0;
 130 }
 131 #endif
 132
 133 void dump_stack(void)
 134 {
 135         show_stack(NULL, NULL);
 136 }
 137
 138 EXPORT_SYMBOL(dump_stack);
 139
 140 void __init
 141 trap_init(void)
 142 {
 143         /* Nothing needs to be done */
 144 }