1/*
2 *  Copyright (C) 1991, 1992  Linus Torvalds
3 *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
4 *  Copyright (C) 2009  Matt Fleming
5 *  Copyright (C) 2002 - 2012  Paul Mundt
6 *
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License.  See the file "COPYING" in the main directory of this archive
9 * for more details.
10 */
11#include <linux/kallsyms.h>
12#include <linux/ftrace.h>
13#include <linux/debug_locks.h>
14#include <linux/kdebug.h>
15#include <linux/export.h>
16#include <linux/uaccess.h>
17#include <asm/unwinder.h>
18#include <asm/stacktrace.h>
19
20void dump_mem(const char *str, unsigned long bottom, unsigned long top)
21{
22	unsigned long p;
23	int i;
24
25	printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top);
26
27	for (p = bottom & ~31; p < top; ) {
28		printk("%04lx: ", p & 0xffff);
29
30		for (i = 0; i < 8; i++, p += 4) {
31			unsigned int val;
32
33			if (p < bottom || p >= top)
34				printk("         ");
35			else {
36				if (__get_user(val, (unsigned int __user *)p)) {
37					printk("\n");
38					return;
39				}
40				printk("%08x ", val);
41			}
42		}
43		printk("\n");
44	}
45}
46
47void printk_address(unsigned long address, int reliable)
48{
49	printk(" [<%p>] %s%pS\n", (void *) address,
50			reliable ? "" : "? ", (void *) address);
51}
52
53#ifdef CONFIG_FUNCTION_GRAPH_TRACER
54static void
55print_ftrace_graph_addr(unsigned long addr, void *data,
56			const struct stacktrace_ops *ops,
57			struct thread_info *tinfo, int *graph)
58{
59	struct task_struct *task = tinfo->task;
60	unsigned long ret_addr;
61	int index = task->curr_ret_stack;
62
63	if (addr != (unsigned long)return_to_handler)
64		return;
65
66	if (!task->ret_stack || index < *graph)
67		return;
68
69	index -= *graph;
70	ret_addr = task->ret_stack[index].ret;
71
72	ops->address(data, ret_addr, 1);
73
74	(*graph)++;
75}
76#else
77static inline void
78print_ftrace_graph_addr(unsigned long addr, void *data,
79			const struct stacktrace_ops *ops,
80			struct thread_info *tinfo, int *graph)
81{ }
82#endif
83
84void
85stack_reader_dump(struct task_struct *task, struct pt_regs *regs,
86		  unsigned long *sp, const struct stacktrace_ops *ops,
87		  void *data)
88{
89	struct thread_info *context;
90	int graph = 0;
91
92	context = (struct thread_info *)
93		((unsigned long)sp & (~(THREAD_SIZE - 1)));
94
95	while (!kstack_end(sp)) {
96		unsigned long addr = *sp++;
97
98		if (__kernel_text_address(addr)) {
99			ops->address(data, addr, 1);
100
101			print_ftrace_graph_addr(addr, data, ops,
102						context, &graph);
103		}
104	}
105}
106
107static int print_trace_stack(void *data, char *name)
108{
109	printk("%s <%s> ", (char *)data, name);
110	return 0;
111}
112
113/*
114 * Print one address/symbol entries per line.
115 */
116static void print_trace_address(void *data, unsigned long addr, int reliable)
117{
118	printk("%s", (char *)data);
119	printk_address(addr, reliable);
120}
121
122static const struct stacktrace_ops print_trace_ops = {
123	.stack = print_trace_stack,
124	.address = print_trace_address,
125};
126
127void show_trace(struct task_struct *tsk, unsigned long *sp,
128		struct pt_regs *regs)
129{
130	if (regs && user_mode(regs))
131		return;
132
133	printk("\nCall trace:\n");
134
135	unwind_stack(tsk, regs, sp, &print_trace_ops, "");
136
137	printk("\n");
138
139	if (!tsk)
140		tsk = current;
141
142	debug_show_held_locks(tsk);
143}
144
145void show_stack(struct task_struct *tsk, unsigned long *sp)
146{
147	unsigned long stack;
148
149	if (!tsk)
150		tsk = current;
151	if (tsk == current)
152		sp = (unsigned long *)current_stack_pointer;
153	else
154		sp = (unsigned long *)tsk->thread.sp;
155
156	stack = (unsigned long)sp;
157	dump_mem("Stack: ", stack, THREAD_SIZE +
158		 (unsigned long)task_stack_page(tsk));
159	show_trace(tsk, sp, NULL);
160}
161