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