1 /* 2 * Copyright (C) 1991, 1992 Linus Torvalds 3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs 4 */ 5 #include <linux/kallsyms.h> 6 #include <linux/kprobes.h> 7 #include <linux/uaccess.h> 8 #include <linux/hardirq.h> 9 #include <linux/kdebug.h> 10 #include <linux/export.h> 11 #include <linux/ptrace.h> 12 #include <linux/kexec.h> 13 #include <linux/sysfs.h> 14 #include <linux/bug.h> 15 #include <linux/nmi.h> 16 17 #include <asm/stacktrace.h> 18 19 void stack_type_str(enum stack_type type, const char **begin, const char **end) 20 { 21 switch (type) { 22 case STACK_TYPE_IRQ: 23 case STACK_TYPE_SOFTIRQ: 24 *begin = "IRQ"; 25 *end = "EOI"; 26 break; 27 default: 28 *begin = NULL; 29 *end = NULL; 30 } 31 } 32 33 static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info) 34 { 35 unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack); 36 unsigned long *end = begin + (THREAD_SIZE / sizeof(long)); 37 38 if (stack < begin || stack >= end) 39 return false; 40 41 info->type = STACK_TYPE_IRQ; 42 info->begin = begin; 43 info->end = end; 44 45 /* 46 * See irq_32.c -- the next stack pointer is stored at the beginning of 47 * the stack. 48 */ 49 info->next_sp = (unsigned long *)*begin; 50 51 return true; 52 } 53 54 static bool in_softirq_stack(unsigned long *stack, struct stack_info *info) 55 { 56 unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack); 57 unsigned long *end = begin + (THREAD_SIZE / sizeof(long)); 58 59 if (stack < begin || stack >= end) 60 return false; 61 62 info->type = STACK_TYPE_SOFTIRQ; 63 info->begin = begin; 64 info->end = end; 65 66 /* 67 * The next stack pointer is stored at the beginning of the stack. 68 * See irq_32.c. 69 */ 70 info->next_sp = (unsigned long *)*begin; 71 72 return true; 73 } 74 75 int get_stack_info(unsigned long *stack, struct task_struct *task, 76 struct stack_info *info, unsigned long *visit_mask) 77 { 78 if (!stack) 79 goto unknown; 80 81 task = task ? : current; 82 83 if (in_task_stack(stack, task, info)) 84 return 0; 85 86 if (task != current) 87 goto unknown; 88 89 if (in_hardirq_stack(stack, info)) 90 return 0; 91 92 if (in_softirq_stack(stack, info)) 93 return 0; 94 95 unknown: 96 info->type = STACK_TYPE_UNKNOWN; 97 return -EINVAL; 98 } 99 100 void dump_trace(struct task_struct *task, struct pt_regs *regs, 101 unsigned long *stack, unsigned long bp, 102 const struct stacktrace_ops *ops, void *data) 103 { 104 unsigned long visit_mask = 0; 105 int graph = 0; 106 107 task = task ? : current; 108 stack = stack ? : get_stack_pointer(task, regs); 109 bp = bp ? : (unsigned long)get_frame_pointer(task, regs); 110 111 for (;;) { 112 const char *begin_str, *end_str; 113 struct stack_info info; 114 115 if (get_stack_info(stack, task, &info, &visit_mask)) 116 break; 117 118 stack_type_str(info.type, &begin_str, &end_str); 119 120 if (begin_str && ops->stack(data, begin_str) < 0) 121 break; 122 123 bp = ops->walk_stack(task, stack, bp, ops, data, &info, &graph); 124 125 if (end_str && ops->stack(data, end_str) < 0) 126 break; 127 128 stack = info.next_sp; 129 130 touch_nmi_watchdog(); 131 } 132 } 133 EXPORT_SYMBOL(dump_trace); 134 135 void 136 show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, 137 unsigned long *sp, unsigned long bp, char *log_lvl) 138 { 139 unsigned long *stack; 140 int i; 141 142 sp = sp ? : get_stack_pointer(task, regs); 143 144 stack = sp; 145 for (i = 0; i < kstack_depth_to_print; i++) { 146 if (kstack_end(stack)) 147 break; 148 if ((i % STACKSLOTS_PER_LINE) == 0) { 149 if (i != 0) 150 pr_cont("\n"); 151 printk("%s %08lx", log_lvl, *stack++); 152 } else 153 pr_cont(" %08lx", *stack++); 154 touch_nmi_watchdog(); 155 } 156 pr_cont("\n"); 157 show_trace_log_lvl(task, regs, sp, bp, log_lvl); 158 } 159 160 161 void show_regs(struct pt_regs *regs) 162 { 163 int i; 164 165 show_regs_print_info(KERN_EMERG); 166 __show_regs(regs, !user_mode(regs)); 167 168 /* 169 * When in-kernel, we also print out the stack and code at the 170 * time of the fault.. 171 */ 172 if (!user_mode(regs)) { 173 unsigned int code_prologue = code_bytes * 43 / 64; 174 unsigned int code_len = code_bytes; 175 unsigned char c; 176 u8 *ip; 177 178 pr_emerg("Stack:\n"); 179 show_stack_log_lvl(NULL, regs, NULL, 0, KERN_EMERG); 180 181 pr_emerg("Code:"); 182 183 ip = (u8 *)regs->ip - code_prologue; 184 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) { 185 /* try starting at IP */ 186 ip = (u8 *)regs->ip; 187 code_len = code_len - code_prologue + 1; 188 } 189 for (i = 0; i < code_len; i++, ip++) { 190 if (ip < (u8 *)PAGE_OFFSET || 191 probe_kernel_address(ip, c)) { 192 pr_cont(" Bad EIP value."); 193 break; 194 } 195 if (ip == (u8 *)regs->ip) 196 pr_cont(" <%02x>", c); 197 else 198 pr_cont(" %02x", c); 199 } 200 } 201 pr_cont("\n"); 202 } 203 204 int is_valid_bugaddr(unsigned long ip) 205 { 206 unsigned short ud2; 207 208 if (ip < PAGE_OFFSET) 209 return 0; 210 if (probe_kernel_address((unsigned short *)ip, ud2)) 211 return 0; 212 213 return ud2 == 0x0b0f; 214 } 215