xref: /openbmc/linux/arch/sh/kernel/dumpstack.c (revision 9cfc5c90)
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 
20 void 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 
47 void 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
54 static void
55 print_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
77 static inline void
78 print_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 
84 void
85 stack_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 
107 static 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  */
116 static void print_trace_address(void *data, unsigned long addr, int reliable)
117 {
118 	printk("%s", (char *)data);
119 	printk_address(addr, reliable);
120 }
121 
122 static const struct stacktrace_ops print_trace_ops = {
123 	.stack = print_trace_stack,
124 	.address = print_trace_address,
125 };
126 
127 void 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 
145 void 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