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/bug.h>
  14 #include <linux/nmi.h>
  15 #include <linux/sysfs.h>
  16
  17 #include <asm/stacktrace.h>
  18
  19 #include "dumpstack.h"
  20
  21 /* Just a stub for now */
  22 int x86_is_stack_id(int id, char *name)
  23 {
  24         return 0;
  25 }
  26
  27 void dump_trace(struct task_struct *task, struct pt_regs *regs,
  28                 unsigned long *stack, unsigned long bp,
  29                 const struct stacktrace_ops *ops, void *data)
  30 {
  31         int graph = 0;
  32
  33         if (!task)
  34                 task = current;
  35
  36         if (!stack) {
  37                 unsigned long dummy;
  38                 stack = &dummy;
  39                 if (task && task != current)
  40                         stack = (unsigned long *)task->thread.sp;
  41         }
  42
  43 #ifdef CONFIG_FRAME_POINTER
  44         if (!bp) {
  45                 if (task == current) {
  46                         /* Grab bp right from our regs */
  47                         get_bp(bp);
  48                 } else {
  49                         /* bp is the last reg pushed by switch_to */
  50                         bp = *(unsigned long *) task->thread.sp;
  51                 }
  52         }
  53 #endif
  54
  55         for (;;) {
  56                 struct thread_info *context;
  57
  58                 context = (struct thread_info *)
  59                         ((unsigned long)stack & (~(THREAD_SIZE - 1)));
  60                 bp = print_context_stack(context, stack, bp, ops,
  61                                          data, NULL, &graph);
  62
  63                 stack = (unsigned long *)context->previous_esp;
  64                 if (!stack)
  65                         break;
  66                 if (ops->stack(data, "IRQ") < 0)
  67                         break;
  68                 touch_nmi_watchdog();
  69         }
  70 }
  71 EXPORT_SYMBOL(dump_trace);
  72
  73 void
  74 show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
  75                 unsigned long *sp, unsigned long bp, char *log_lvl)
  76 {
  77         unsigned long *stack;
  78         int i;
  79
  80         if (sp == NULL) {
  81                 if (task)
  82                         sp = (unsigned long *)task->thread.sp;
  83                 else
  84                         sp = (unsigned long *)&sp;
  85         }
  86
  87         stack = sp;
  88         for (i = 0; i < kstack_depth_to_print; i++) {
  89                 if (kstack_end(stack))
  90                         break;
  91                 if (i && ((i % STACKSLOTS_PER_LINE) == 0))
  92                         printk("\n%s", log_lvl);
  93                 printk(" %08lx", *stack++);
  94                 touch_nmi_watchdog();
  95         }
  96         printk("\n");
  97         show_trace_log_lvl(task, regs, sp, bp, log_lvl);
  98 }
  99
 100
 101 void show_registers(struct pt_regs *regs)
 102 {
 103         int i;
 104
 105         print_modules();
 106         __show_regs(regs, 0);
 107
 108         printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
 109                 TASK_COMM_LEN, current->comm, task_pid_nr(current),
 110                 current_thread_info(), current, task_thread_info(current));
 111         /*
 112          * When in-kernel, we also print out the stack and code at the
 113          * time of the fault..
 114          */
 115         if (!user_mode_vm(regs)) {
 116                 unsigned int code_prologue = code_bytes * 43 / 64;
 117                 unsigned int code_len = code_bytes;
 118                 unsigned char c;
 119                 u8 *ip;
 120
 121                 printk(KERN_EMERG "Stack:\n");
 122                 show_stack_log_lvl(NULL, regs, &regs->sp,
 123                                 0, KERN_EMERG);
 124
 125                 printk(KERN_EMERG "Code: ");
 126
 127                 ip = (u8 *)regs->ip - code_prologue;
 128                 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
 129                         /* try starting at IP */
 130                         ip = (u8 *)regs->ip;
 131                         code_len = code_len - code_prologue + 1;
 132                 }
 133                 for (i = 0; i < code_len; i++, ip++) {
 134                         if (ip < (u8 *)PAGE_OFFSET ||
 135                                         probe_kernel_address(ip, c)) {
 136                                 printk(" Bad EIP value.");
 137                                 break;
 138                         }
 139                         if (ip == (u8 *)regs->ip)
 140                                 printk("<%02x> ", c);
 141                         else
 142                                 printk("%02x ", c);
 143                 }
 144         }
 145         printk("\n");
 146 }
 147
 148 int is_valid_bugaddr(unsigned long ip)
 149 {
 150         unsigned short ud2;
 151
 152         if (ip < PAGE_OFFSET)
 153                 return 0;
 154         if (probe_kernel_address((unsigned short *)ip, ud2))
 155                 return 0;
 156
 157         return ud2 == 0x0b0f;
 158 }
 159