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/module.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 static void *is_irq_stack(void *p, void *irq) 20 { 21 if (p < irq || p >= (irq + THREAD_SIZE)) 22 return NULL; 23 return irq + THREAD_SIZE; 24 } 25 26 27 static void *is_hardirq_stack(unsigned long *stack, int cpu) 28 { 29 void *irq = per_cpu(hardirq_stack, cpu); 30 31 return is_irq_stack(stack, irq); 32 } 33 34 static void *is_softirq_stack(unsigned long *stack, int cpu) 35 { 36 void *irq = per_cpu(softirq_stack, cpu); 37 38 return is_irq_stack(stack, irq); 39 } 40 41 void dump_trace(struct task_struct *task, struct pt_regs *regs, 42 unsigned long *stack, unsigned long bp, 43 const struct stacktrace_ops *ops, void *data) 44 { 45 const unsigned cpu = get_cpu(); 46 int graph = 0; 47 u32 *prev_esp; 48 49 if (!task) 50 task = current; 51 52 if (!stack) { 53 unsigned long dummy; 54 55 stack = &dummy; 56 if (task != current) 57 stack = (unsigned long *)task->thread.sp; 58 } 59 60 if (!bp) 61 bp = stack_frame(task, regs); 62 63 for (;;) { 64 struct thread_info *context; 65 void *end_stack; 66 67 end_stack = is_hardirq_stack(stack, cpu); 68 if (!end_stack) 69 end_stack = is_softirq_stack(stack, cpu); 70 71 context = task_thread_info(task); 72 bp = ops->walk_stack(context, stack, bp, ops, data, 73 end_stack, &graph); 74 75 /* Stop if not on irq stack */ 76 if (!end_stack) 77 break; 78 79 /* The previous esp is saved on the bottom of the stack */ 80 prev_esp = (u32 *)(end_stack - THREAD_SIZE); 81 stack = (unsigned long *)*prev_esp; 82 if (!stack) 83 break; 84 85 if (ops->stack(data, "IRQ") < 0) 86 break; 87 touch_nmi_watchdog(); 88 } 89 put_cpu(); 90 } 91 EXPORT_SYMBOL(dump_trace); 92 93 void 94 show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, 95 unsigned long *sp, unsigned long bp, char *log_lvl) 96 { 97 unsigned long *stack; 98 int i; 99 100 if (sp == NULL) { 101 if (task) 102 sp = (unsigned long *)task->thread.sp; 103 else 104 sp = (unsigned long *)&sp; 105 } 106 107 stack = sp; 108 for (i = 0; i < kstack_depth_to_print; i++) { 109 if (kstack_end(stack)) 110 break; 111 if ((i % STACKSLOTS_PER_LINE) == 0) { 112 if (i != 0) 113 pr_cont("\n"); 114 printk("%s %08lx", log_lvl, *stack++); 115 } else 116 pr_cont(" %08lx", *stack++); 117 touch_nmi_watchdog(); 118 } 119 pr_cont("\n"); 120 show_trace_log_lvl(task, regs, sp, bp, log_lvl); 121 } 122 123 124 void show_regs(struct pt_regs *regs) 125 { 126 int i; 127 128 show_regs_print_info(KERN_EMERG); 129 __show_regs(regs, !user_mode(regs)); 130 131 /* 132 * When in-kernel, we also print out the stack and code at the 133 * time of the fault.. 134 */ 135 if (!user_mode(regs)) { 136 unsigned int code_prologue = code_bytes * 43 / 64; 137 unsigned int code_len = code_bytes; 138 unsigned char c; 139 u8 *ip; 140 141 pr_emerg("Stack:\n"); 142 show_stack_log_lvl(NULL, regs, ®s->sp, 0, KERN_EMERG); 143 144 pr_emerg("Code:"); 145 146 ip = (u8 *)regs->ip - code_prologue; 147 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) { 148 /* try starting at IP */ 149 ip = (u8 *)regs->ip; 150 code_len = code_len - code_prologue + 1; 151 } 152 for (i = 0; i < code_len; i++, ip++) { 153 if (ip < (u8 *)PAGE_OFFSET || 154 probe_kernel_address(ip, c)) { 155 pr_cont(" Bad EIP value."); 156 break; 157 } 158 if (ip == (u8 *)regs->ip) 159 pr_cont(" <%02x>", c); 160 else 161 pr_cont(" %02x", c); 162 } 163 } 164 pr_cont("\n"); 165 } 166 167 int is_valid_bugaddr(unsigned long ip) 168 { 169 unsigned short ud2; 170 171 if (ip < PAGE_OFFSET) 172 return 0; 173 if (probe_kernel_address((unsigned short *)ip, ud2)) 174 return 0; 175 176 return ud2 == 0x0b0f; 177 } 178