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 #include "dumpstack.h"
  20
  21
  22 void dump_trace(struct task_struct *task, struct pt_regs *regs,
  23                 unsigned long *stack, unsigned long bp,
  24                 const struct stacktrace_ops *ops, void *data)
  25 {
  26         int graph = 0;
  27
  28         if (!task)
  29                 task = current;
  30
  31         if (!stack) {
  32                 unsigned long dummy;
  33
  34                 stack = &dummy;
  35                 if (task && task != current)
  36                         stack = (unsigned long *)task->thread.sp;
  37         }
  38
  39 #ifdef CONFIG_FRAME_POINTER
  40         if (!bp) {
  41                 if (task == current) {
  42                         /* Grab bp right from our regs */
  43                         get_bp(bp);
  44                 } else {
  45                         /* bp is the last reg pushed by switch_to */
  46                         bp = *(unsigned long *) task->thread.sp;
  47                 }
  48         }
  49 #endif
  50
  51         for (;;) {
  52                 struct thread_info *context;
  53
  54                 context = (struct thread_info *)
  55                         ((unsigned long)stack & (~(THREAD_SIZE - 1)));
  56                 bp = ops->walk_stack(context, stack, bp, ops, data, NULL, &graph);
  57
  58                 stack = (unsigned long *)context->previous_esp;
  59                 if (!stack)
  60                         break;
  61                 if (ops->stack(data, "IRQ") < 0)
  62                         break;
  63                 touch_nmi_watchdog();
  64         }
  65 }
  66 EXPORT_SYMBOL(dump_trace);
  67
  68 void
  69 show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
  70                    unsigned long *sp, unsigned long bp, char *log_lvl)
  71 {
  72         unsigned long *stack;
  73         int i;
  74
  75         if (sp == NULL) {
  76                 if (task)
  77                         sp = (unsigned long *)task->thread.sp;
  78                 else
  79                         sp = (unsigned long *)&sp;
  80         }
  81
  82         stack = sp;
  83         for (i = 0; i < kstack_depth_to_print; i++) {
  84                 if (kstack_end(stack))
  85                         break;
  86                 if (i && ((i % STACKSLOTS_PER_LINE) == 0))
  87                         printk("\n%s", log_lvl);
  88                 printk(" %08lx", *stack++);
  89                 touch_nmi_watchdog();
  90         }
  91         printk("\n");
  92         show_trace_log_lvl(task, regs, sp, bp, log_lvl);
  93 }
  94
  95
  96 void show_registers(struct pt_regs *regs)
  97 {
  98         int i;
  99
 100         print_modules();
 101         __show_regs(regs, 0);
 102
 103         printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
 104                 TASK_COMM_LEN, current->comm, task_pid_nr(current),
 105                 current_thread_info(), current, task_thread_info(current));
 106         /*
 107          * When in-kernel, we also print out the stack and code at the
 108          * time of the fault..
 109          */
 110         if (!user_mode_vm(regs)) {
 111                 unsigned int code_prologue = code_bytes * 43 / 64;
 112                 unsigned int code_len = code_bytes;
 113                 unsigned char c;
 114                 u8 *ip;
 115
 116                 printk(KERN_EMERG "Stack:\n");
 117                 show_stack_log_lvl(NULL, regs, &regs->sp,
 118                                 0, KERN_EMERG);
 119
 120                 printk(KERN_EMERG "Code: ");
 121
 122                 ip = (u8 *)regs->ip - code_prologue;
 123                 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
 124                         /* try starting at IP */
 125                         ip = (u8 *)regs->ip;
 126                         code_len = code_len - code_prologue + 1;
 127                 }
 128                 for (i = 0; i < code_len; i++, ip++) {
 129                         if (ip < (u8 *)PAGE_OFFSET ||
 130                                         probe_kernel_address(ip, c)) {
 131                                 printk(" Bad EIP value.");
 132                                 break;
 133                         }
 134                         if (ip == (u8 *)regs->ip)
 135                                 printk("<%02x> ", c);
 136                         else
 137                                 printk("%02x ", c);
 138                 }
 139         }
 140         printk("\n");
 141 }
 142
 143 int is_valid_bugaddr(unsigned long ip)
 144 {
 145         unsigned short ud2;
 146
 147         if (ip < PAGE_OFFSET)
 148                 return 0;
 149         if (probe_kernel_address((unsigned short *)ip, ud2))
 150                 return 0;
 151
 152         return ud2 == 0x0b0f;
 153 }