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