x86: Constify a few items
[linux-3.10.git] / 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 }