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