traps.c

来自「LINUX 2.6.17.4的源码」· C语言 代码 · 共 1,211 行 · 第 1/3 页

/*
 *  linux/arch/i386/traps.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  Pentium III FXSR, SSE support
 *	Gareth Hughes <[e-mail]>, May 2000
 */

/*
 * 'Traps.c' handles hardware traps and faults after we have saved some
 * state in 'asm.s'.
 */
#include <linux/config.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/highmem.h>
#include <linux/kallsyms.h>
#include <linux/ptrace.h>
#include <linux/utsname.h>
#include <linux/kprobes.h>
#include <linux/kexec.h>

#ifdef CONFIG_EISA
#include <linux/ioport.h>
#include <linux/eisa.h>
#endif

#ifdef CONFIG_MCA
#include <linux/mca.h>
#endif

#include <asm/processor.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/atomic.h>
#include <asm/debugreg.h>
#include <asm/desc.h>
#include <asm/i387.h>
#include <asm/nmi.h>

#include <asm/smp.h>
#include <asm/arch_hooks.h>
#include <asm/kdebug.h>

#include <linux/module.h>

#include "mach_traps.h"

asmlinkage int system_call(void);

struct desc_struct default_ldt[] = { { 0, 0 }, { 0, 0 }, { 0, 0 },
		{ 0, 0 }, { 0, 0 } };

/* Do we ignore FPU interrupts ? */
char ignore_fpu_irq = 0;

/*
 * The IDT has to be page-aligned to simplify the Pentium
 * F0 0F bug workaround.. We have a special link segment
 * for this.
 */
struct desc_struct idt_table[256] __attribute__((__section__(".data.idt"))) = { {0, 0}, };

asmlinkage void divide_error(void);
asmlinkage void debug(void);
asmlinkage void nmi(void);
asmlinkage void int3(void);
asmlinkage void overflow(void);
asmlinkage void bounds(void);
asmlinkage void invalid_op(void);
asmlinkage void device_not_available(void);
asmlinkage void coprocessor_segment_overrun(void);
asmlinkage void invalid_TSS(void);
asmlinkage void segment_not_present(void);
asmlinkage void stack_segment(void);
asmlinkage void general_protection(void);
asmlinkage void page_fault(void);
asmlinkage void coprocessor_error(void);
asmlinkage void simd_coprocessor_error(void);
asmlinkage void alignment_check(void);
asmlinkage void spurious_interrupt_bug(void);
asmlinkage void machine_check(void);

static int kstack_depth_to_print = 24;
ATOMIC_NOTIFIER_HEAD(i386die_chain);

int register_die_notifier(struct notifier_block *nb)
{
	vmalloc_sync_all();
	return atomic_notifier_chain_register(&i386die_chain, nb);
}
EXPORT_SYMBOL(register_die_notifier);

int unregister_die_notifier(struct notifier_block *nb)
{
	return atomic_notifier_chain_unregister(&i386die_chain, nb);
}
EXPORT_SYMBOL(unregister_die_notifier);

static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
{
	return	p > (void *)tinfo &&
		p < (void *)tinfo + THREAD_SIZE - 3;
}

/*
 * Print CONFIG_STACK_BACKTRACE_COLS address/symbol entries per line.
 */
static inline int print_addr_and_symbol(unsigned long addr, char *log_lvl,
					int printed)
{
	if (!printed)
		printk(log_lvl);

#if CONFIG_STACK_BACKTRACE_COLS == 1
	printk(" [<%08lx>] ", addr);
#else
	printk(" <%08lx> ", addr);
#endif
	print_symbol("%s", addr);

	printed = (printed + 1) % CONFIG_STACK_BACKTRACE_COLS;
	if (printed)
		printk(" ");
	else
		printk("\n");

	return printed;
}

static inline unsigned long print_context_stack(struct thread_info *tinfo,
				unsigned long *stack, unsigned long ebp,
				char *log_lvl)
{
	unsigned long addr;
	int printed = 0; /* nr of entries already printed on current line */

#ifdef	CONFIG_FRAME_POINTER
	while (valid_stack_ptr(tinfo, (void *)ebp)) {
		addr = *(unsigned long *)(ebp + 4);
		printed = print_addr_and_symbol(addr, log_lvl, printed);
		ebp = *(unsigned long *)ebp;
	}
#else
	while (valid_stack_ptr(tinfo, stack)) {
		addr = *stack++;
		if (__kernel_text_address(addr))
			printed = print_addr_and_symbol(addr, log_lvl, printed);
	}
#endif
	if (printed)
		printk("\n");

	return ebp;
}

static void show_trace_log_lvl(struct task_struct *task,
			       unsigned long *stack, char *log_lvl)
{
	unsigned long ebp;

	if (!task)
		task = current;

	if (task == current) {
		/* Grab ebp right from our regs */
		asm ("movl %%ebp, %0" : "=r" (ebp) : );
	} else {
		/* ebp is the last reg pushed by switch_to */
		ebp = *(unsigned long *) task->thread.esp;
	}

	while (1) {
		struct thread_info *context;
		context = (struct thread_info *)
			((unsigned long)stack & (~(THREAD_SIZE - 1)));
		ebp = print_context_stack(context, stack, ebp, log_lvl);
		stack = (unsigned long*)context->previous_esp;
		if (!stack)
			break;
		printk("%s =======================\n", log_lvl);
	}
}

void show_trace(struct task_struct *task, unsigned long * stack)
{
	show_trace_log_lvl(task, stack, "");
}

static void show_stack_log_lvl(struct task_struct *task, unsigned long *esp,
			       char *log_lvl)
{
	unsigned long *stack;
	int i;

	if (esp == NULL) {
		if (task)
			esp = (unsigned long*)task->thread.esp;
		else
			esp = (unsigned long *)&esp;
	}

	stack = esp;
	for(i = 0; i < kstack_depth_to_print; i++) {
		if (kstack_end(stack))
			break;
		if (i && ((i % 8) == 0))
			printk("\n%s       ", log_lvl);
		printk("%08lx ", *stack++);
	}
	printk("\n%sCall Trace:\n", log_lvl);
	show_trace_log_lvl(task, esp, log_lvl);
}

void show_stack(struct task_struct *task, unsigned long *esp)
{
	printk("       ");
	show_stack_log_lvl(task, esp, "");
}

/*
 * The architecture-independent dump_stack generator
 */
void dump_stack(void)
{
	unsigned long stack;

	show_trace(current, &stack);
}

EXPORT_SYMBOL(dump_stack);

void show_registers(struct pt_regs *regs)
{
	int i;
	int in_kernel = 1;
	unsigned long esp;
	unsigned short ss;

	esp = (unsigned long) (&regs->esp);
	savesegment(ss, ss);
	if (user_mode_vm(regs)) {
		in_kernel = 0;
		esp = regs->esp;
		ss = regs->xss & 0xffff;
	}
	print_modules();
	printk(KERN_EMERG "CPU:    %d\nEIP:    %04x:[<%08lx>]    %s VLI\n"
			"EFLAGS: %08lx   (%s %.*s) \n",
		smp_processor_id(), 0xffff & regs->xcs, regs->eip,
		print_tainted(), regs->eflags, system_utsname.release,
		(int)strcspn(system_utsname.version, " "),
		system_utsname.version);
	print_symbol(KERN_EMERG "EIP is at %s\n", regs->eip);
	printk(KERN_EMERG "eax: %08lx   ebx: %08lx   ecx: %08lx   edx: %08lx\n",
		regs->eax, regs->ebx, regs->ecx, regs->edx);
	printk(KERN_EMERG "esi: %08lx   edi: %08lx   ebp: %08lx   esp: %08lx\n",
		regs->esi, regs->edi, regs->ebp, esp);
	printk(KERN_EMERG "ds: %04x   es: %04x   ss: %04x\n",
		regs->xds & 0xffff, regs->xes & 0xffff, ss);
	printk(KERN_EMERG "Process %s (pid: %d, threadinfo=%p task=%p)",
		current->comm, current->pid, current_thread_info(), current);
	/*
	 * When in-kernel, we also print out the stack and code at the
	 * time of the fault..
	 */
	if (in_kernel) {
		u8 __user *eip;

		printk("\n" KERN_EMERG "Stack: ");
		show_stack_log_lvl(NULL, (unsigned long *)esp, KERN_EMERG);

		printk(KERN_EMERG "Code: ");

		eip = (u8 __user *)regs->eip - 43;
		for (i = 0; i < 64; i++, eip++) {
			unsigned char c;

			if (eip < (u8 __user *)PAGE_OFFSET || __get_user(c, eip)) {
				printk(" Bad EIP value.");
				break;
			}
			if (eip == (u8 __user *)regs->eip)
				printk("<%02x> ", c);
			else
				printk("%02x ", c);
		}
	}
	printk("\n");
}	

static void handle_BUG(struct pt_regs *regs)
{
	unsigned short ud2;
	unsigned short line;
	char *file;
	char c;
	unsigned long eip;

	eip = regs->eip;

	if (eip < PAGE_OFFSET)
		goto no_bug;
	if (__get_user(ud2, (unsigned short __user *)eip))
		goto no_bug;
	if (ud2 != 0x0b0f)
		goto no_bug;
	if (__get_user(line, (unsigned short __user *)(eip + 2)))
		goto bug;
	if (__get_user(file, (char * __user *)(eip + 4)) ||
		(unsigned long)file < PAGE_OFFSET || __get_user(c, file))
		file = "<bad filename>";

	printk(KERN_EMERG "------------[ cut here ]------------\n");
	printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);

no_bug:
	return;

	/* Here we know it was a BUG but file-n-line is unavailable */
bug:
	printk(KERN_EMERG "Kernel BUG\n");
}

/* This is gone through when something in the kernel
 * has done something bad and is about to be terminated.
*/
void die(const char * str, struct pt_regs * regs, long err)
{
	static struct {
		spinlock_t lock;
		u32 lock_owner;
		int lock_owner_depth;
	} die = {
		.lock =			SPIN_LOCK_UNLOCKED,
		.lock_owner =		-1,
		.lock_owner_depth =	0
	};
	static int die_counter;
	unsigned long flags;

	oops_enter();

	if (die.lock_owner != raw_smp_processor_id()) {
		console_verbose();
		spin_lock_irqsave(&die.lock, flags);
		die.lock_owner = smp_processor_id();
		die.lock_owner_depth = 0;
		bust_spinlocks(1);
	}
	else
		local_save_flags(flags);

	if (++die.lock_owner_depth < 3) {
		int nl = 0;
		unsigned long esp;
		unsigned short ss;

		handle_BUG(regs);
		printk(KERN_EMERG "%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
#ifdef CONFIG_PREEMPT
		printk(KERN_EMERG "PREEMPT ");
		nl = 1;
#endif
#ifdef CONFIG_SMP
		if (!nl)
			printk(KERN_EMERG);
		printk("SMP ");
		nl = 1;
#endif
#ifdef CONFIG_DEBUG_PAGEALLOC
		if (!nl)
			printk(KERN_EMERG);
		printk("DEBUG_PAGEALLOC");
		nl = 1;
#endif
		if (nl)
			printk("\n");
		if (notify_die(DIE_OOPS, str, regs, err,
					current->thread.trap_no, SIGSEGV) !=
				NOTIFY_STOP) {
			show_registers(regs);
			/* Executive summary in case the oops scrolled away */
			esp = (unsigned long) (&regs->esp);
			savesegment(ss, ss);
			if (user_mode(regs)) {
				esp = regs->esp;
				ss = regs->xss & 0xffff;
			}
			printk(KERN_EMERG "EIP: [<%08lx>] ", regs->eip);
			print_symbol("%s", regs->eip);
			printk(" SS:ESP %04x:%08lx\n", ss, esp);
		}
		else