xref: /openbmc/linux/arch/x86/kernel/dumpstack_32.c (revision fd589a8f)
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/utsname.h>
9 #include <linux/hardirq.h>
10 #include <linux/kdebug.h>
11 #include <linux/module.h>
12 #include <linux/ptrace.h>
13 #include <linux/kexec.h>
14 #include <linux/bug.h>
15 #include <linux/nmi.h>
16 #include <linux/sysfs.h>
17 
18 #include <asm/stacktrace.h>
19 
20 #include "dumpstack.h"
21 
22 /* Just a stub for now */
23 int x86_is_stack_id(int id, char *name)
24 {
25 	return 0;
26 }
27 
28 void dump_trace(struct task_struct *task, struct pt_regs *regs,
29 		unsigned long *stack, unsigned long bp,
30 		const struct stacktrace_ops *ops, void *data)
31 {
32 	int graph = 0;
33 
34 	if (!task)
35 		task = current;
36 
37 	if (!stack) {
38 		unsigned long dummy;
39 		stack = &dummy;
40 		if (task && task != current)
41 			stack = (unsigned long *)task->thread.sp;
42 	}
43 
44 #ifdef CONFIG_FRAME_POINTER
45 	if (!bp) {
46 		if (task == current) {
47 			/* Grab bp right from our regs */
48 			get_bp(bp);
49 		} else {
50 			/* bp is the last reg pushed by switch_to */
51 			bp = *(unsigned long *) task->thread.sp;
52 		}
53 	}
54 #endif
55 
56 	for (;;) {
57 		struct thread_info *context;
58 
59 		context = (struct thread_info *)
60 			((unsigned long)stack & (~(THREAD_SIZE - 1)));
61 		bp = print_context_stack(context, stack, bp, ops,
62 					 data, NULL, &graph);
63 
64 		stack = (unsigned long *)context->previous_esp;
65 		if (!stack)
66 			break;
67 		if (ops->stack(data, "IRQ") < 0)
68 			break;
69 		touch_nmi_watchdog();
70 	}
71 }
72 EXPORT_SYMBOL(dump_trace);
73 
74 void
75 show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
76 		unsigned long *sp, unsigned long bp, char *log_lvl)
77 {
78 	unsigned long *stack;
79 	int i;
80 
81 	if (sp == NULL) {
82 		if (task)
83 			sp = (unsigned long *)task->thread.sp;
84 		else
85 			sp = (unsigned long *)&sp;
86 	}
87 
88 	stack = sp;
89 	for (i = 0; i < kstack_depth_to_print; i++) {
90 		if (kstack_end(stack))
91 			break;
92 		if (i && ((i % STACKSLOTS_PER_LINE) == 0))
93 			printk("\n%s", log_lvl);
94 		printk(" %08lx", *stack++);
95 		touch_nmi_watchdog();
96 	}
97 	printk("\n");
98 	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
99 }
100 
101 
102 void show_registers(struct pt_regs *regs)
103 {
104 	int i;
105 
106 	print_modules();
107 	__show_regs(regs, 0);
108 
109 	printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
110 		TASK_COMM_LEN, current->comm, task_pid_nr(current),
111 		current_thread_info(), current, task_thread_info(current));
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_vm(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 		printk(KERN_EMERG "Stack:\n");
123 		show_stack_log_lvl(NULL, regs, &regs->sp,
124 				0, KERN_EMERG);
125 
126 		printk(KERN_EMERG "Code: ");
127 
128 		ip = (u8 *)regs->ip - code_prologue;
129 		if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
130 			/* try starting at IP */
131 			ip = (u8 *)regs->ip;
132 			code_len = code_len - code_prologue + 1;
133 		}
134 		for (i = 0; i < code_len; i++, ip++) {
135 			if (ip < (u8 *)PAGE_OFFSET ||
136 					probe_kernel_address(ip, c)) {
137 				printk(" Bad EIP value.");
138 				break;
139 			}
140 			if (ip == (u8 *)regs->ip)
141 				printk("<%02x> ", c);
142 			else
143 				printk("%02x ", c);
144 		}
145 	}
146 	printk("\n");
147 }
148 
149 int is_valid_bugaddr(unsigned long ip)
150 {
151 	unsigned short ud2;
152 
153 	if (ip < PAGE_OFFSET)
154 		return 0;
155 	if (probe_kernel_address((unsigned short *)ip, ud2))
156 		return 0;
157 
158 	return ud2 == 0x0b0f;
159 }
160 
161