xref: /openbmc/linux/arch/x86/kernel/dumpstack_32.c (revision e8e0929d)
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/bug.h>
14 #include <linux/nmi.h>
15 #include <linux/sysfs.h>
16 
17 #include <asm/stacktrace.h>
18 
19 #include "dumpstack.h"
20 
21 /* Just a stub for now */
22 int x86_is_stack_id(int id, char *name)
23 {
24 	return 0;
25 }
26 
27 void dump_trace(struct task_struct *task, struct pt_regs *regs,
28 		unsigned long *stack, unsigned long bp,
29 		const struct stacktrace_ops *ops, void *data)
30 {
31 	int graph = 0;
32 
33 	if (!task)
34 		task = current;
35 
36 	if (!stack) {
37 		unsigned long dummy;
38 		stack = &dummy;
39 		if (task && task != current)
40 			stack = (unsigned long *)task->thread.sp;
41 	}
42 
43 #ifdef CONFIG_FRAME_POINTER
44 	if (!bp) {
45 		if (task == current) {
46 			/* Grab bp right from our regs */
47 			get_bp(bp);
48 		} else {
49 			/* bp is the last reg pushed by switch_to */
50 			bp = *(unsigned long *) task->thread.sp;
51 		}
52 	}
53 #endif
54 
55 	for (;;) {
56 		struct thread_info *context;
57 
58 		context = (struct thread_info *)
59 			((unsigned long)stack & (~(THREAD_SIZE - 1)));
60 		bp = print_context_stack(context, stack, bp, ops,
61 					 data, NULL, &graph);
62 
63 		stack = (unsigned long *)context->previous_esp;
64 		if (!stack)
65 			break;
66 		if (ops->stack(data, "IRQ") < 0)
67 			break;
68 		touch_nmi_watchdog();
69 	}
70 }
71 EXPORT_SYMBOL(dump_trace);
72 
73 void
74 show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
75 		unsigned long *sp, unsigned long bp, char *log_lvl)
76 {
77 	unsigned long *stack;
78 	int i;
79 
80 	if (sp == NULL) {
81 		if (task)
82 			sp = (unsigned long *)task->thread.sp;
83 		else
84 			sp = (unsigned long *)&sp;
85 	}
86 
87 	stack = sp;
88 	for (i = 0; i < kstack_depth_to_print; i++) {
89 		if (kstack_end(stack))
90 			break;
91 		if (i && ((i % STACKSLOTS_PER_LINE) == 0))
92 			printk("\n%s", log_lvl);
93 		printk(" %08lx", *stack++);
94 		touch_nmi_watchdog();
95 	}
96 	printk("\n");
97 	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
98 }
99 
100 
101 void show_registers(struct pt_regs *regs)
102 {
103 	int i;
104 
105 	print_modules();
106 	__show_regs(regs, 0);
107 
108 	printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
109 		TASK_COMM_LEN, current->comm, task_pid_nr(current),
110 		current_thread_info(), current, task_thread_info(current));
111 	/*
112 	 * When in-kernel, we also print out the stack and code at the
113 	 * time of the fault..
114 	 */
115 	if (!user_mode_vm(regs)) {
116 		unsigned int code_prologue = code_bytes * 43 / 64;
117 		unsigned int code_len = code_bytes;
118 		unsigned char c;
119 		u8 *ip;
120 
121 		printk(KERN_EMERG "Stack:\n");
122 		show_stack_log_lvl(NULL, regs, &regs->sp,
123 				0, KERN_EMERG);
124 
125 		printk(KERN_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 				printk(" Bad EIP value.");
137 				break;
138 			}
139 			if (ip == (u8 *)regs->ip)
140 				printk("<%02x> ", c);
141 			else
142 				printk("%02x ", c);
143 		}
144 	}
145 	printk("\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 
160