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, 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 task = task ? : current; 50 stack = stack ? : get_stack_pointer(task, regs); 51 bp = bp ? : (unsigned long)get_frame_pointer(task, regs); 52 53 for (;;) { 54 void *end_stack; 55 56 end_stack = is_hardirq_stack(stack, cpu); 57 if (!end_stack) 58 end_stack = is_softirq_stack(stack, cpu); 59 60 bp = ops->walk_stack(task, stack, bp, ops, data, 61 end_stack, &graph); 62 63 /* Stop if not on irq stack */ 64 if (!end_stack) 65 break; 66 67 /* The previous esp is saved on the bottom of the stack */ 68 prev_esp = (u32 *)(end_stack - THREAD_SIZE); 69 stack = (unsigned long *)*prev_esp; 70 if (!stack) 71 break; 72 73 if (ops->stack(data, "IRQ") < 0) 74 break; 75 touch_nmi_watchdog(); 76 } 77 put_cpu(); 78 } 79 EXPORT_SYMBOL(dump_trace); 80 81 void 82 show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, 83 unsigned long *sp, unsigned long bp, char *log_lvl) 84 { 85 unsigned long *stack; 86 int i; 87 88 sp = sp ? : get_stack_pointer(task, regs); 89 90 stack = sp; 91 for (i = 0; i < kstack_depth_to_print; i++) { 92 if (kstack_end(stack)) 93 break; 94 if ((i % STACKSLOTS_PER_LINE) == 0) { 95 if (i != 0) 96 pr_cont("\n"); 97 printk("%s %08lx", log_lvl, *stack++); 98 } else 99 pr_cont(" %08lx", *stack++); 100 touch_nmi_watchdog(); 101 } 102 pr_cont("\n"); 103 show_trace_log_lvl(task, regs, sp, bp, log_lvl); 104 } 105 106 107 void show_regs(struct pt_regs *regs) 108 { 109 int i; 110 111 show_regs_print_info(KERN_EMERG); 112 __show_regs(regs, !user_mode(regs)); 113 114 /* 115 * When in-kernel, we also print out the stack and code at the 116 * time of the fault.. 117 */ 118 if (!user_mode(regs)) { 119 unsigned int code_prologue = code_bytes * 43 / 64; 120 unsigned int code_len = code_bytes; 121 unsigned char c; 122 u8 *ip; 123 124 pr_emerg("Stack:\n"); 125 show_stack_log_lvl(NULL, regs, NULL, 0, KERN_EMERG); 126 127 pr_emerg("Code:"); 128 129 ip = (u8 *)regs->ip - code_prologue; 130 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) { 131 /* try starting at IP */ 132 ip = (u8 *)regs->ip; 133 code_len = code_len - code_prologue + 1; 134 } 135 for (i = 0; i < code_len; i++, ip++) { 136 if (ip < (u8 *)PAGE_OFFSET || 137 probe_kernel_address(ip, c)) { 138 pr_cont(" Bad EIP value."); 139 break; 140 } 141 if (ip == (u8 *)regs->ip) 142 pr_cont(" <%02x>", c); 143 else 144 pr_cont(" %02x", c); 145 } 146 } 147 pr_cont("\n"); 148 } 149 150 int is_valid_bugaddr(unsigned long ip) 151 { 152 unsigned short ud2; 153 154 if (ip < PAGE_OFFSET) 155 return 0; 156 if (probe_kernel_address((unsigned short *)ip, ud2)) 157 return 0; 158 159 return ud2 == 0x0b0f; 160 } 161