/arch/x86/kernel/dumpstack_32.c

  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#include "dumpstack.h"
 20
 21
 22void dump_trace(struct task_struct *task, struct pt_regs *regs,
 23		unsigned long *stack, unsigned long bp,
 24		const struct stacktrace_ops *ops, void *data)
 25{
 26	int graph = 0;
 27
 28	if (!task)
 29		task = current;
 30
 31	if (!stack) {
 32		unsigned long dummy;
 33
 34		stack = &dummy;
 35		if (task && task != current)
 36			stack = (unsigned long *)task->thread.sp;
 37	}
 38
 39#ifdef CONFIG_FRAME_POINTER
 40	if (!bp) {
 41		if (task == current) {
 42			/* Grab bp right from our regs */
 43			get_bp(bp);
 44		} else {
 45			/* bp is the last reg pushed by switch_to */
 46			bp = *(unsigned long *) task->thread.sp;
 47		}
 48	}
 49#endif
 50
 51	for (;;) {
 52		struct thread_info *context;
 53
 54		context = (struct thread_info *)
 55			((unsigned long)stack & (~(THREAD_SIZE - 1)));
 56		bp = ops->walk_stack(context, stack, bp, ops, data, NULL, &graph);
 57
 58		stack = (unsigned long *)context->previous_esp;
 59		if (!stack)
 60			break;
 61		if (ops->stack(data, "IRQ") < 0)
 62			break;
 63		touch_nmi_watchdog();
 64	}
 65}
 66EXPORT_SYMBOL(dump_trace);
 67
 68void
 69show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
 70		   unsigned long *sp, unsigned long bp, char *log_lvl)
 71{
 72	unsigned long *stack;
 73	int i;
 74
 75	if (sp == NULL) {
 76		if (task)
 77			sp = (unsigned long *)task->thread.sp;
 78		else
 79			sp = (unsigned long *)&sp;
 80	}
 81
 82	stack = sp;
 83	for (i = 0; i < kstack_depth_to_print; i++) {
 84		if (kstack_end(stack))
 85			break;
 86		if (i && ((i % STACKSLOTS_PER_LINE) == 0))
 87			printk("\n%s", log_lvl);
 88		printk(" %08lx", *stack++);
 89		touch_nmi_watchdog();
 90	}
 91	printk("\n");
 92	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
 93}
 94
 95
 96void show_registers(struct pt_regs *regs)
 97{
 98	int i;
 99
100	print_modules();
101	__show_regs(regs, 0);
102
103	printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
104		TASK_COMM_LEN, current->comm, task_pid_nr(current),
105		current_thread_info(), current, task_thread_info(current));
106	/*
107	 * When in-kernel, we also print out the stack and code at the
108	 * time of the fault..
109	 */
110	if (!user_mode_vm(regs)) {
111		unsigned int code_prologue = code_bytes * 43 / 64;
112		unsigned int code_len = code_bytes;
113		unsigned char c;
114		u8 *ip;
115
116		printk(KERN_EMERG "Stack:\n");
117		show_stack_log_lvl(NULL, regs, &regs->sp,
118				0, KERN_EMERG);
119
120		printk(KERN_EMERG "Code: ");
121
122		ip = (u8 *)regs->ip - code_prologue;
123		if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
124			/* try starting at IP */
125			ip = (u8 *)regs->ip;
126			code_len = code_len - code_prologue + 1;
127		}
128		for (i = 0; i < code_len; i++, ip++) {
129			if (ip < (u8 *)PAGE_OFFSET ||
130					probe_kernel_address(ip, c)) {
131				printk(" Bad EIP value.");
132				break;
133			}
134			if (ip == (u8 *)regs->ip)
135				printk("<%02x> ", c);
136			else
137				printk("%02x ", c);
138		}
139	}
140	printk("\n");
141}
142
143int is_valid_bugaddr(unsigned long ip)
144{
145	unsigned short ud2;
146
147	if (ip < PAGE_OFFSET)
148		return 0;
149	if (probe_kernel_address((unsigned short *)ip, ud2))
150		return 0;
151
152	return ud2 == 0x0b0f;
153}