Robin Getz | 2a12c46 | 2010-03-11 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 | */ |
| 19 | static bool is_bfin_call(unsigned short *addr) |
| 20 | { |
Robin Getz | 9a95e2f | 2010-03-15 17:42:07 +0000 | [diff] [blame] | 21 | unsigned int opcode; |
Robin Getz | 2a12c46 | 2010-03-11 16:24:18 +0000 | [diff] [blame] | 22 | |
Robin Getz | 9a95e2f | 2010-03-15 17:42:07 +0000 | [diff] [blame] | 23 | if (!get_instruction(&opcode, addr)) |
Robin Getz | 2a12c46 | 2010-03-11 16:24:18 +0000 | [diff] [blame] | 24 | return false; |
| 25 | |
| 26 | if ((opcode >= 0x0060 && opcode <= 0x0067) || |
Robin Getz | 9a95e2f | 2010-03-15 17:42:07 +0000 | [diff] [blame] | 27 | (opcode >= 0x0070 && opcode <= 0x0077) || |
| 28 | (opcode >= 0xE3000000 && opcode <= 0xE3FFFFFF)) |
Robin Getz | 2a12c46 | 2010-03-11 16:24:18 +0000 | [diff] [blame] | 29 | return true; |
| 30 | |
| 31 | return false; |
| 32 | |
| 33 | } |
| 34 | |
| 35 | void 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 | } |
| 161 | EXPORT_SYMBOL(show_stack); |
| 162 | |
| 163 | void 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(); |
Tejun Heo | 196779b | 2013-04-30 15:27:12 -0700 | [diff] [blame] | 171 | dump_stack_print_info(KERN_DEFAULT); |
Robin Getz | 2a12c46 | 2010-03-11 16:24:18 +0000 | [diff] [blame] | 172 | show_stack(current, &stack); |
| 173 | trace_buffer_restore(tflags); |
| 174 | } |
| 175 | EXPORT_SYMBOL(dump_stack); |