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
19static void *is_irq_stack(void *p, void *irq)
20{
21	if (p < irq || p >= (irq + THREAD_SIZE))
22		return NULL;
23	return irq + THREAD_SIZE;
24}
25
26
27static void *is_hardirq_stack(unsigned long *stack, int cpu)
28{
29	void *irq = per_cpu(hardirq_stack, cpu);
30
31	return is_irq_stack(stack, irq);
32}
33
34static void *is_softirq_stack(unsigned long *stack, int cpu)
35{
36	void *irq = per_cpu(softirq_stack, cpu);
37
38	return is_irq_stack(stack, irq);
39}
40
41void dump_trace(struct task_struct *task, struct pt_regs *regs,
42		unsigned long *stack, unsigned long bp,
43		const struct stacktrace_ops *ops, void *data)
44{
45	const unsigned cpu = get_cpu();
46	int graph = 0;
47	u32 *prev_esp;
48
49	if (!task)
50		task = current;
51
52	if (!stack) {
53		unsigned long dummy;
54
55		stack = &dummy;
56		if (task != current)
57			stack = (unsigned long *)task->thread.sp;
58	}
59
60	if (!bp)
61		bp = stack_frame(task, regs);
62
63	for (;;) {
64		struct thread_info *context;
65		void *end_stack;
66
67		end_stack = is_hardirq_stack(stack, cpu);
68		if (!end_stack)
69			end_stack = is_softirq_stack(stack, cpu);
70
71		context = task_thread_info(task);
72		bp = ops->walk_stack(context, stack, bp, ops, data,
73				     end_stack, &graph);
74
75		/* Stop if not on irq stack */
76		if (!end_stack)
77			break;
78
79		/* The previous esp is saved on the bottom of the stack */
80		prev_esp = (u32 *)(end_stack - THREAD_SIZE);
81		stack = (unsigned long *)*prev_esp;
82		if (!stack)
83			break;
84
85		if (ops->stack(data, "IRQ") < 0)
86			break;
87		touch_nmi_watchdog();
88	}
89	put_cpu();
90}
91EXPORT_SYMBOL(dump_trace);
92
93void
94show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
95		   unsigned long *sp, unsigned long bp, char *log_lvl)
96{
97	unsigned long *stack;
98	int i;
99
100	if (sp == NULL) {
101		if (task)
102			sp = (unsigned long *)task->thread.sp;
103		else
104			sp = (unsigned long *)&sp;
105	}
106
107	stack = sp;
108	for (i = 0; i < kstack_depth_to_print; i++) {
109		if (kstack_end(stack))
110			break;
111		if ((i % STACKSLOTS_PER_LINE) == 0) {
112			if (i != 0)
113				pr_cont("\n");
114			printk("%s %08lx", log_lvl, *stack++);
115		} else
116			pr_cont(" %08lx", *stack++);
117		touch_nmi_watchdog();
118	}
119	pr_cont("\n");
120	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
121}
122
123
124void show_regs(struct pt_regs *regs)
125{
126	int i;
127
128	show_regs_print_info(KERN_EMERG);
129	__show_regs(regs, !user_mode(regs));
130
131	/*
132	 * When in-kernel, we also print out the stack and code at the
133	 * time of the fault..
134	 */
135	if (!user_mode(regs)) {
136		unsigned int code_prologue = code_bytes * 43 / 64;
137		unsigned int code_len = code_bytes;
138		unsigned char c;
139		u8 *ip;
140
141		pr_emerg("Stack:\n");
142		show_stack_log_lvl(NULL, regs, &regs->sp, 0, KERN_EMERG);
143
144		pr_emerg("Code:");
145
146		ip = (u8 *)regs->ip - code_prologue;
147		if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
148			/* try starting at IP */
149			ip = (u8 *)regs->ip;
150			code_len = code_len - code_prologue + 1;
151		}
152		for (i = 0; i < code_len; i++, ip++) {
153			if (ip < (u8 *)PAGE_OFFSET ||
154					probe_kernel_address(ip, c)) {
155				pr_cont("  Bad EIP value.");
156				break;
157			}
158			if (ip == (u8 *)regs->ip)
159				pr_cont(" <%02x>", c);
160			else
161				pr_cont(" %02x", c);
162		}
163	}
164	pr_cont("\n");
165}
166
167int is_valid_bugaddr(unsigned long ip)
168{
169	unsigned short ud2;
170
171	if (ip < PAGE_OFFSET)
172		return 0;
173	if (probe_kernel_address((unsigned short *)ip, ud2))
174		return 0;
175
176	return ud2 == 0x0b0f;
177}
178