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review.evervolv.com / android_kernel_htc_msm8960 / 05d42746b51a1ffca1b42f31524b69ce6654d1e5 / . / arch / blackfin / kernel / dumpstack.c
blob: 5cfbaa2982116d3875fbeeeff902cddb7865b491 [file] [log] [blame]
Robin Getz2a12c462010-03-11 16:24:18 +0000[diff] [blame]1/* Provide basic stack dumping functions
2 *
3 * Copyright 2004-2009 Analog Devices Inc.
4 *
5 * Licensed under the GPL-2 or later
6 */
7
8#include <linux/kernel.h>
9#include <linux/thread_info.h>
10#include <linux/mm.h>
11#include <linux/uaccess.h>
12#include <linux/module.h>
13#include <asm/trace.h>
14
15/*
16 * Checks to see if the address pointed to is either a
17 * 16-bit CALL instruction, or a 32-bit CALL instruction
18 */
19static bool is_bfin_call(unsigned short *addr)
20{
Robin Getz9a95e2f2010-03-15 17:42:07 +0000[diff] [blame]21 unsigned int opcode;
Robin Getz2a12c462010-03-11 16:24:18 +0000[diff] [blame]22
Robin Getz9a95e2f2010-03-15 17:42:07 +0000[diff] [blame]23 if (!get_instruction(&opcode, addr))
Robin Getz2a12c462010-03-11 16:24:18 +0000[diff] [blame]24 return false;
25
26 if ((opcode >= 0x0060 && opcode <= 0x0067) ||
Robin Getz9a95e2f2010-03-15 17:42:07 +0000[diff] [blame]27 (opcode >= 0x0070 && opcode <= 0x0077) ||
28 (opcode >= 0xE3000000 && opcode <= 0xE3FFFFFF))
Robin Getz2a12c462010-03-11 16:24:18 +0000[diff] [blame]29 return true;
30
31 return false;
32
33}
34
35void show_stack(struct task_struct *task, unsigned long *stack)
36{
37#ifdef CONFIG_PRINTK
38 unsigned int *addr, *endstack, *fp = 0, *frame;
39 unsigned short *ins_addr;
40 char buf[150];
41 unsigned int i, j, ret_addr, frame_no = 0;
42
43 /*
44 * If we have been passed a specific stack, use that one otherwise
45 * if we have been passed a task structure, use that, otherwise
46 * use the stack of where the variable "stack" exists
47 */
48
49 if (stack == NULL) {
50 if (task) {
51 /* We know this is a kernel stack, so this is the start/end */
52 stack = (unsigned long *)task->thread.ksp;
53 endstack = (unsigned int *)(((unsigned int)(stack) & ~(THREAD_SIZE - 1)) + THREAD_SIZE);
54 } else {
55 /* print out the existing stack info */
56 stack = (unsigned long *)&stack;
57 endstack = (unsigned int *)PAGE_ALIGN((unsigned int)stack);
58 }
59 } else
60 endstack = (unsigned int *)PAGE_ALIGN((unsigned int)stack);
61
62 printk(KERN_NOTICE "Stack info:\n");
63 decode_address(buf, (unsigned int)stack);
64 printk(KERN_NOTICE " SP: [0x%p] %s\n", stack, buf);
65
66 if (!access_ok(VERIFY_READ, stack, (unsigned int)endstack - (unsigned int)stack)) {
67 printk(KERN_NOTICE "Invalid stack pointer\n");
68 return;
69 }
70
71 /* First thing is to look for a frame pointer */
72 for (addr = (unsigned int *)((unsigned int)stack & ~0xF); addr < endstack; addr++) {
73 if (*addr & 0x1)
74 continue;
75 ins_addr = (unsigned short *)*addr;
76 ins_addr--;
77 if (is_bfin_call(ins_addr))
78 fp = addr - 1;
79
80 if (fp) {
81 /* Let's check to see if it is a frame pointer */
82 while (fp >= (addr - 1) && fp < endstack
83 && fp && ((unsigned int) fp & 0x3) == 0)
84 fp = (unsigned int *)*fp;
85 if (fp == 0 || fp == endstack) {
86 fp = addr - 1;
87 break;
88 }
89 fp = 0;
90 }
91 }
92 if (fp) {
93 frame = fp;
94 printk(KERN_NOTICE " FP: (0x%p)\n", fp);
95 } else
96 frame = 0;
97
98 /*
99 * Now that we think we know where things are, we
100 * walk the stack again, this time printing things out
101 * incase there is no frame pointer, we still look for
102 * valid return addresses
103 */
104
105 /* First time print out data, next time, print out symbols */
106 for (j = 0; j <= 1; j++) {
107 if (j)
108 printk(KERN_NOTICE "Return addresses in stack:\n");
109 else
110 printk(KERN_NOTICE " Memory from 0x%08lx to %p", ((long unsigned int)stack & ~0xF), endstack);
111
112 fp = frame;
113 frame_no = 0;
114
115 for (addr = (unsigned int *)((unsigned int)stack & ~0xF), i = 0;
116 addr < endstack; addr++, i++) {
117
118 ret_addr = 0;
119 if (!j && i % 8 == 0)
120 printk(KERN_NOTICE "%p:", addr);
121
122 /* if it is an odd address, or zero, just skip it */
123 if (*addr & 0x1 || !*addr)
124 goto print;
125
126 ins_addr = (unsigned short *)*addr;
127
128 /* Go back one instruction, and see if it is a CALL */
129 ins_addr--;
130 ret_addr = is_bfin_call(ins_addr);
131 print:
132 if (!j && stack == (unsigned long *)addr)
133 printk("[%08x]", *addr);
134 else if (ret_addr)
135 if (j) {
136 decode_address(buf, (unsigned int)*addr);
137 if (frame == addr) {
138 printk(KERN_NOTICE " frame %2i : %s\n", frame_no, buf);
139 continue;
140 }
141 printk(KERN_NOTICE " address : %s\n", buf);
142 } else
143 printk("<%08x>", *addr);
144 else if (fp == addr) {
145 if (j)
146 frame = addr+1;
147 else
148 printk("(%08x)", *addr);
149
150 fp = (unsigned int *)*addr;
151 frame_no++;
152
153 } else if (!j)
154 printk(" %08x ", *addr);
155 }
156 if (!j)
157 printk("\n");
158 }
159#endif
160}
161EXPORT_SYMBOL(show_stack);
162
163void dump_stack(void)
164{
165 unsigned long stack;
166#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
167 int tflags;
168#endif
169 trace_buffer_save(tflags);
170 dump_bfin_trace_buffer();
171 show_stack(current, &stack);
172 trace_buffer_restore(tflags);
173}
174EXPORT_SYMBOL(dump_stack);