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/utsname.h>
   9 #include <linux/hardirq.h>
  10 #include <linux/kdebug.h>
  11 #include <linux/module.h>
  12 #include <linux/ptrace.h>
  13 #include <linux/kexec.h>
  14 #include <linux/bug.h>
  15 #include <linux/nmi.h>
  16 #include <linux/sysfs.h>
  17
  18 #include <asm/stacktrace.h>
  19
  20 #include "dumpstack.h"
  21
  22 /* Just a stub for now */
  23 int x86_is_stack_id(int id, char *name)
  24 {
  25         return 0;
  26 }
  27
  28 void dump_trace(struct task_struct *task, struct pt_regs *regs,
  29                 unsigned long *stack, unsigned long bp,
  30                 const struct stacktrace_ops *ops, void *data)
  31 {
  32         int graph = 0;
  33
  34         if (!task)
  35                 task = current;
  36
  37         if (!stack) {
  38                 unsigned long dummy;
  39                 stack = &dummy;
  40                 if (task && task != current)
  41                         stack = (unsigned long *)task->thread.sp;
  42         }
  43
  44 #ifdef CONFIG_FRAME_POINTER
  45         if (!bp) {
  46                 if (task == current) {
  47                         /* Grab bp right from our regs */
  48                         get_bp(bp);
  49                 } else {
  50                         /* bp is the last reg pushed by switch_to */
  51                         bp = *(unsigned long *) task->thread.sp;
  52                 }
  53         }
  54 #endif
  55
  56         for (;;) {
  57                 struct thread_info *context;
  58
  59                 context = (struct thread_info *)
  60                         ((unsigned long)stack & (~(THREAD_SIZE - 1)));
  61                 bp = print_context_stack(context, stack, bp, ops,
  62                                          data, NULL, &graph);
  63
  64                 stack = (unsigned long *)context->previous_esp;
  65                 if (!stack)
  66                         break;
  67                 if (ops->stack(data, "IRQ") < 0)
  68                         break;
  69                 touch_nmi_watchdog();
  70         }
  71 }
  72 EXPORT_SYMBOL(dump_trace);
  73
  74 void
  75 show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
  76                 unsigned long *sp, unsigned long bp, char *log_lvl)
  77 {
  78         unsigned long *stack;
  79         int i;
  80
  81         if (sp == NULL) {
  82                 if (task)
  83                         sp = (unsigned long *)task->thread.sp;
  84                 else
  85                         sp = (unsigned long *)&sp;
  86         }
  87
  88         stack = sp;
  89         for (i = 0; i < kstack_depth_to_print; i++) {
  90                 if (kstack_end(stack))
  91                         break;
  92                 if (i && ((i % STACKSLOTS_PER_LINE) == 0))
  93                         printk("\n%s", log_lvl);
  94                 printk(" %08lx", *stack++);
  95                 touch_nmi_watchdog();
  96         }
  97         printk("\n");
  98         show_trace_log_lvl(task, regs, sp, bp, log_lvl);
  99 }
 100
 101
 102 void show_registers(struct pt_regs *regs)
 103 {
 104         int i;
 105
 106         print_modules();
 107         __show_regs(regs, 0);
 108
 109         printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
 110                 TASK_COMM_LEN, current->comm, task_pid_nr(current),
 111                 current_thread_info(), current, task_thread_info(current));
 112         /*
 113          * When in-kernel, we also print out the stack and code at the
 114          * time of the fault..
 115          */
 116         if (!user_mode_vm(regs)) {
 117                 unsigned int code_prologue = code_bytes * 43 / 64;
 118                 unsigned int code_len = code_bytes;
 119                 unsigned char c;
 120                 u8 *ip;
 121
 122                 printk(KERN_EMERG "Stack:\n");
 123                 show_stack_log_lvl(NULL, regs, &regs->sp,
 124                                 0, KERN_EMERG);
 125
 126                 printk(KERN_EMERG "Code: ");
 127
 128                 ip = (u8 *)regs->ip - code_prologue;
 129                 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
 130                         /* try starting at IP */
 131                         ip = (u8 *)regs->ip;
 132                         code_len = code_len - code_prologue + 1;
 133                 }
 134                 for (i = 0; i < code_len; i++, ip++) {
 135                         if (ip < (u8 *)PAGE_OFFSET ||
 136                                         probe_kernel_address(ip, c)) {
 137                                 printk(" Bad EIP value.");
 138                                 break;
 139                         }
 140                         if (ip == (u8 *)regs->ip)
 141                                 printk("<%02x> ", c);
 142                         else
 143                                 printk("%02x ", c);
 144                 }
 145         }
 146         printk("\n");
 147 }
 148
 149 int is_valid_bugaddr(unsigned long ip)
 150 {
 151         unsigned short ud2;
 152
 153         if (ip < PAGE_OFFSET)
 154                 return 0;
 155         if (probe_kernel_address((unsigned short *)ip, ud2))
 156                 return 0;
 157
 158         return ud2 == 0x0b0f;
 159 }
 160