arch/x86/kernel/dumpstack_32.c

   1 /*
   2  *  Copyright (C) 1991, 1992  Linus Torvalds
   3  *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
   4  */
   5 #include <linux/kallsyms.h>
   6 #include <linux/kprobes.h>
   7 #include <linux/uaccess.h>
   8 #include <linux/hardirq.h>
   9 #include <linux/kdebug.h>
  10 #include <linux/module.h>
  11 #include <linux/ptrace.h>
  12 #include <linux/kexec.h>
  13 #include <linux/sysfs.h>
  14 #include <linux/bug.h>
  15 #include <linux/nmi.h>
  16
  17 #include <asm/stacktrace.h>
  18
  19
  20 void dump_trace(struct task_struct *task, struct pt_regs *regs,
  21                 unsigned long *stack, unsigned long bp,
  22                 const struct stacktrace_ops *ops, void *data)
  23 {
  24         int graph = 0;
  25
  26         if (!task)
  27                 task = current;
  28
  29         bp = stack_frame(task, regs);
  30         if (try_stack_unwind(task, regs, &stack, &bp, ops, data))
  31                 return;
  32
  33         if (!stack) {
  34                 unsigned long dummy;
  35
  36                 stack = &dummy;
  37                 if (task && task != current)
  38                         stack = (unsigned long *)task->thread.sp;
  39         }
  40
  41         if (!bp)
  42                 bp = stack_frame(task, regs);
  43
  44         for (;;) {
  45                 struct thread_info *context;
  46
  47                 context = (struct thread_info *)
  48                         ((unsigned long)stack & (~(THREAD_SIZE - 1)));
  49                 bp = ops->walk_stack(context, stack, bp, ops, data, NULL, &graph);
  50
  51                 stack = (unsigned long *)context->previous_esp;
  52                 if (!stack)
  53                         break;
  54                 if (ops->stack(data, "IRQ") < 0)
  55                         break;
  56                 touch_nmi_watchdog();
  57         }
  58 }
  59 EXPORT_SYMBOL(dump_trace);
  60
  61 void
  62 show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
  63                    unsigned long *sp, unsigned long bp, char *log_lvl)
  64 {
  65         unsigned long *stack;
  66         int i;
  67
  68         if (sp == NULL) {
  69                 if (task)
  70                         sp = (unsigned long *)task->thread.sp;
  71                 else
  72                         sp = (unsigned long *)&sp;
  73         }
  74
  75         stack = sp;
  76         for (i = 0; i < kstack_depth_to_print; i++) {
  77                 if (kstack_end(stack))
  78                         break;
  79                 if (i && ((i % STACKSLOTS_PER_LINE) == 0))
  80                         printk(KERN_CONT "\n");
  81                 printk(KERN_CONT " %08lx", *stack++);
  82                 touch_nmi_watchdog();
  83         }
  84         printk(KERN_CONT "\n");
  85         show_trace_log_lvl(task, regs, sp, bp, log_lvl);
  86 }
  87
  88
  89 void show_registers(struct pt_regs *regs)
  90 {
  91         int i;
  92
  93         print_modules();
  94         __show_regs(regs, !user_mode_vm(regs));
  95
  96         printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
  97                 TASK_COMM_LEN, current->comm, task_pid_nr(current),
  98                 current_thread_info(), current, task_thread_info(current));
  99         /*
 100          * When in-kernel, we also print out the stack and code at the
 101          * time of the fault..
 102          */
 103         if (!user_mode_vm(regs)) {
 104                 unsigned int code_prologue = code_bytes * 43 / 64;
 105                 unsigned int code_len = code_bytes;
 106                 unsigned char c;
 107                 u8 *ip;
 108
 109                 printk(KERN_EMERG "Stack:\n");
 110                 show_stack_log_lvl(NULL, regs, &regs->sp, 0, KERN_EMERG);
 111
 112                 printk(KERN_EMERG "Code: ");
 113
 114                 ip = (u8 *)regs->ip - code_prologue;
 115                 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
 116                         /* try starting at IP */
 117                         ip = (u8 *)regs->ip;
 118                         code_len = code_len - code_prologue + 1;
 119                 }
 120                 for (i = 0; i < code_len; i++, ip++) {
 121                         if (ip < (u8 *)PAGE_OFFSET ||
 122                                         probe_kernel_address(ip, c)) {
 123                                 printk(KERN_CONT " Bad EIP value.");
 124                                 break;
 125                         }
 126                         if (ip == (u8 *)regs->ip)
 127                                 printk(KERN_CONT "<%02x> ", c);
 128                         else
 129                                 printk(KERN_CONT "%02x ", c);
 130                 }
 131         }
 132         printk(KERN_CONT "\n");
 133 }
 134
 135 int is_valid_bugaddr(unsigned long ip)
 136 {
 137         unsigned short ud2;
 138
 139         if (ip < PAGE_OFFSET)
 140                 return 0;
 141         if (probe_kernel_address((unsigned short *)ip, ud2))
 142                 return 0;
 143
 144         return ud2 == 0x0b0f;
 145 }