release/src-rt-6.x.4708/linux/linux-2.6.36/arch/sh/kernel/traps.c

   1 #include <linux/bug.h>
   2 #include <linux/io.h>
   3 #include <linux/types.h>
   4 #include <linux/kdebug.h>
   5 #include <linux/signal.h>
   6 #include <linux/sched.h>
   7 #include <linux/uaccess.h>
   8 #include <linux/hardirq.h>
   9 #include <asm/unwinder.h>
  10 #include <asm/system.h>
  11
  12 #ifdef CONFIG_GENERIC_BUG
  13 static void handle_BUG(struct pt_regs *regs)
  14 {
  15         const struct bug_entry *bug;
  16         unsigned long bugaddr = regs->pc;
  17         enum bug_trap_type tt;
  18
  19         if (!is_valid_bugaddr(bugaddr))
  20                 goto invalid;
  21
  22         bug = find_bug(bugaddr);
  23
  24         /* Switch unwinders when unwind_stack() is called */
  25         if (bug->flags & BUGFLAG_UNWINDER)
  26                 unwinder_faulted = 1;
  27
  28         tt = report_bug(bugaddr, regs);
  29         if (tt == BUG_TRAP_TYPE_WARN) {
  30                 regs->pc += instruction_size(bugaddr);
  31                 return;
  32         }
  33
  34 invalid:
  35         die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
  36 }
  37
  38 int is_valid_bugaddr(unsigned long addr)
  39 {
  40         insn_size_t opcode;
  41
  42         if (addr < PAGE_OFFSET)
  43                 return 0;
  44         if (probe_kernel_address((insn_size_t *)addr, opcode))
  45                 return 0;
  46         if (opcode == TRAPA_BUG_OPCODE)
  47                 return 1;
  48
  49         return 0;
  50 }
  51 #endif
  52
  53 /*
  54  * Generic trap handler.
  55  */
  56 BUILD_TRAP_HANDLER(debug)
  57 {
  58         TRAP_HANDLER_DECL;
  59
  60         /* Rewind */
  61         regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
  62
  63         if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff,
  64                        SIGTRAP) == NOTIFY_STOP)
  65                 return;
  66
  67         force_sig(SIGTRAP, current);
  68 }
  69
  70 /*
  71  * Special handler for BUG() traps.
  72  */
  73 BUILD_TRAP_HANDLER(bug)
  74 {
  75         TRAP_HANDLER_DECL;
  76
  77         /* Rewind */
  78         regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
  79
  80         if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
  81                        SIGTRAP) == NOTIFY_STOP)
  82                 return;
  83
  84 #ifdef CONFIG_GENERIC_BUG
  85         if (__kernel_text_address(instruction_pointer(regs))) {
  86                 insn_size_t insn = *(insn_size_t *)instruction_pointer(regs);
  87                 if (insn == TRAPA_BUG_OPCODE)
  88                         handle_BUG(regs);
  89                 return;
  90         }
  91 #endif
  92
  93         force_sig(SIGTRAP, current);
  94 }
  95
  96 BUILD_TRAP_HANDLER(nmi)
  97 {
  98         unsigned int cpu = smp_processor_id();
  99         TRAP_HANDLER_DECL;
 100
 101         nmi_enter();
 102         nmi_count(cpu)++;
 103
 104         switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) {
 105         case NOTIFY_OK:
 106         case NOTIFY_STOP:
 107                 break;
 108         case NOTIFY_BAD:
 109                 die("Fatal Non-Maskable Interrupt", regs, SIGINT);
 110         default:
 111                 printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n");
 112                 break;
 113         }
 114
 115         nmi_exit();
 116 }