aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/dumpstack_32.c
blob: 39891ff50d037cf9c1cf6ee921427bb558e05975 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/*
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
 */
#include <linux/kallsyms.h>
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
#include <linux/kdebug.h>
#include <linux/module.h>
#include <linux/ptrace.h>
#include <linux/kexec.h>
#include <linux/sysfs.h>
#include <linux/bug.h>
#include <linux/nmi.h>

#include <asm/stacktrace.h>

static void *is_irq_stack(void *p, void *irq)
{
	if (p < irq || p >= (irq + THREAD_SIZE))
		return NULL;
	return irq + THREAD_SIZE;
}


static void *is_hardirq_stack(unsigned long *stack, int cpu)
{
	void *irq = per_cpu(hardirq_stack, cpu);

	return is_irq_stack(stack, irq);
}

static void *is_softirq_stack(unsigned long *stack, int cpu)
{
	void *irq = per_cpu(softirq_stack, cpu);

	return is_irq_stack(stack, irq);
}

void dump_trace(struct task_struct *task, struct pt_regs *regs,
		unsigned long *stack, unsigned long bp,
		const struct stacktrace_ops *ops, void *data)
{
	const unsigned cpu = get_cpu();
	int graph = 0;
	u32 *prev_esp;

	if (!task)
		task = current;

	if (!stack) {
		unsigned long dummy;

		stack = &dummy;
		if (task != current)
			stack = (unsigned long *)task->thread.sp;
	}

	if (!bp)
		bp = stack_frame(task, regs);

	for (;;) {
		struct thread_info *context;
		void *end_stack;

		end_stack = is_hardirq_stack(stack, cpu);
		if (!end_stack)
			end_stack = is_softirq_stack(stack, cpu);

		context = task_thread_info(task);
		bp = ops->walk_stack(context, stack, bp, ops, data,
				     end_stack, &graph);

		/* Stop if not on irq stack */
		if (!end_stack)
			break;

		/* The previous esp is saved on the bottom of the stack */
		prev_esp = (u32 *)(end_stack - THREAD_SIZE);
		stack = (unsigned long *)*prev_esp;
		if (!stack)
			break;

		if (ops->stack(data, "IRQ") < 0)
			break;
		touch_nmi_watchdog();
	}
	put_cpu();
}
EXPORT_SYMBOL(dump_trace);

void
show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
		   unsigned long *sp, unsigned long bp, char *log_lvl)
{
	unsigned long *stack;
	int i;

	if (sp == NULL) {
		if (task)
			sp = (unsigned long *)task->thread.sp;
		else
			sp = (unsigned long *)&sp;
	}

	stack = sp;
	for (i = 0; i < kstack_depth_to_print; i++) {
		if (kstack_end(stack))
			break;
		if (i && ((i % STACKSLOTS_PER_LINE) == 0))
			pr_cont("\n");
		pr_cont(" %08lx", *stack++);
		touch_nmi_watchdog();
	}
	pr_cont("\n");
	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
}


void show_regs(struct pt_regs *regs)
{
	int i;

	show_regs_print_info(KERN_EMERG);
	__show_regs(regs, !user_mode(regs));

	/*
	 * When in-kernel, we also print out the stack and code at the
	 * time of the fault..
	 */
	if (!user_mode(regs)) {
		unsigned int code_prologue = code_bytes * 43 / 64;
		unsigned int code_len = code_bytes;
		unsigned char c;
		u8 *ip;

		pr_emerg("Stack:\n");
		show_stack_log_lvl(NULL, regs, &regs->sp, 0, KERN_EMERG);

		pr_emerg("Code:");

		ip = (u8 *)regs->ip - code_prologue;
		if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
			/* try starting at IP */
			ip = (u8 *)regs->ip;
			code_len = code_len - code_prologue + 1;
		}
		for (i = 0; i < code_len; i++, ip++) {
			if (ip < (u8 *)PAGE_OFFSET ||
					probe_kernel_address(ip, c)) {
				pr_cont("  Bad EIP value.");
				break;
			}
			if (ip == (u8 *)regs->ip)
				pr_cont(" <%02x>", c);
			else
				pr_cont(" %02x", c);
		}
	}
	pr_cont("\n");
}

int is_valid_bugaddr(unsigned long ip)
{
	unsigned short ud2;

	if (ip < PAGE_OFFSET)
		return 0;
	if (probe_kernel_address((unsigned short *)ip, ud2))
		return 0;

	return ud2 == 0x0b0f;
}