traps.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

/*
 *  linux/arch/x86-64/traps.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
 *
 *  Pentium III FXSR, SSE support
 *	Gareth Hughes <[e-mail]>, May 2000
 *
 *  $Id: traps.c,v 1.54 2003/01/10 15:12:03 ak Exp $
 */

/*
 * 'Traps.c' handles hardware traps and faults after we have saved some
 * state in 'entry.S'.
 */
#include <linux/config.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ptrace.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/module.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/kdebug.h>

#include <asm/smp.h>
#include <asm/pgalloc.h>
#include <asm/pda.h>
#include <asm/proto.h>

#include <linux/irq.h>

extern int exception_trace;

extern struct gate_struct idt_table[256]; 

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 double_fault(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 reserved(void);
asmlinkage void alignment_check(void);
asmlinkage void machine_check(void);
asmlinkage void spurious_interrupt_bug(void);
asmlinkage void call_debug(void);

extern char iret_address[];

struct notifier_block *die_chain;
void (*netdump_func) (struct pt_regs *regs) = NULL;
int kstack_depth_to_print = 40;

#ifdef CONFIG_KALLSYMS
#include <linux/kallsyms.h> 
int printk_address(unsigned long address)
{ 
	unsigned long dummy; 
	const char *modname, *secname, *symname;
	unsigned long symstart; 
	char *delim = ":"; 

	/* What a function call! */
	if (!kallsyms_address_to_symbol(address, 
					&modname, &dummy, &dummy, 
					&secname, &dummy, &dummy,
					&symname, &symstart, &dummy)) {
		return printk("[<%016lx>]", address);
	} 
	if (!strcmp(modname, "kernel"))
		modname = delim = ""; 		
        return printk("[<%016lx>]{%s%s%s%s%+ld}",
		      address,delim,modname,delim,symname,address-symstart); 
} 
#else
int printk_address(unsigned long address)
{ 
	return printk("[<%016lx>]", address);
} 
#endif


#ifdef CONFIG_MODULES

extern struct module *module_list;
extern struct module kernel_module;

static inline int kernel_text_address(unsigned long addr)
{
   int retval = 0;
   struct module *mod;

   if (addr >= (unsigned long) &_stext &&
       addr <= (unsigned long) &_etext)
       return 1;

   for (mod = module_list; mod != &kernel_module; mod = mod->next) {
       /* mod_bound tests for addr being inside the vmalloc'ed
        * module area. Of course it'd be better to test only
        * for the .text subset... */
       if (mod_bound(addr, 0, mod)) {
           retval = 1;
           break;
       }
   }

   return retval;
}

#else

static inline int kernel_text_address(unsigned long addr)
{
   return (addr >= (unsigned long) &_stext &&
       addr <= (unsigned long) &_etext);
}

#endif

static inline unsigned long *in_exception_stack(int cpu, unsigned long stack) 
{ 
	int k;
	for (k = 0; k < N_EXCEPTION_STACKS; k++) {
		unsigned long end = init_tss[cpu].ist[k] + EXCEPTION_STKSZ; 

		if (stack >= init_tss[cpu].ist[k]  && stack <= end) 
			return (unsigned long *)end;
	}
	return 0;
} 

void show_trace(unsigned long *stack)
{
	unsigned long addr;
	unsigned long *irqstack, *irqstack_end, *estack_end;
	/* FIXME: should read the cpuid from the APIC; to still work with bogus %gs */
	const int cpu = smp_processor_id();
	int i;

	printk("\nCall Trace: ");

	i = 12;
	estack_end = in_exception_stack(cpu, (unsigned long)stack); 
	if (estack_end) { 
		while (stack < estack_end) { 
			addr = *stack++; 
			if (kernel_text_address(addr)) {  
				i += printk_address(addr);
				i += printk(" "); 
				if (i > 50) { 
					printk("\n       ");
					i = 0;
				} 
			}
		}
		printk(" <EOE> "); 
		i += 7;
		stack = (unsigned long *) estack_end[-2]; 
	}  


	irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
	irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE + 8);

	if (stack >= irqstack && stack < irqstack_end) {
		while (stack < irqstack_end) {
			addr = *stack++;
			/*
			 * If the address is either in the text segment of the
			 * kernel, or in the region which contains vmalloc'ed
			 * memory, it *may* be the address of a calling
			 * routine; if so, print it so that someone tracing
			 * down the cause of the crash will be able to figure
			 * out the call path that was taken.
			 */
			 if (kernel_text_address(addr)) {  
				 i += printk_address(addr);
				 i += printk(" "); 
				 if (i > 50) { 
					 printk("\n       ");
					 i = 0;
				 } 
			 }
		} 
		stack = (unsigned long *) (irqstack_end[-1]);
		i += 7; 
		printk(" <EOI> ");
	} 

	

	while (((long) stack & (THREAD_SIZE-1)) != 0) {
		addr = *stack++;
		if (kernel_text_address(addr)) {  
			i += printk_address(addr);
			i += printk(" "); 
			if (i > 50) { 
				printk("\n       ");
				i = 0;
			} 
		}
	}
	printk("\n");
}

void show_trace_task(struct task_struct *tsk)
{
	unsigned long rsp = tsk->thread.rsp;

	/* User space on another CPU? */
	if ((rsp ^ (unsigned long)tsk) & (PAGE_MASK<<1))
		return;
	show_trace((unsigned long *)rsp);
}

void show_stack(unsigned long * rsp)
{
	unsigned long *stack;
	int i;
	const int cpu = smp_processor_id();
	unsigned long *irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
	unsigned long *irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE);    

	// debugging aid: "show_stack(NULL);" prints the
	// back trace for this cpu.

	if(rsp==NULL)
		rsp=(unsigned long*)&rsp;

	stack = rsp;
	for(i=0; i < kstack_depth_to_print; i++) {
		if (stack >= irqstack && stack <= irqstack_end) {
			if (stack == irqstack_end) {
				stack = (unsigned long *) (irqstack_end[-1]);
				printk(" <EOI> ");
			}
		} else {
			if (((long) stack & (THREAD_SIZE-1)) == 0)
				break;
		}
		if (i && ((i % 4) == 0))
			printk("\n       ");
		printk("%016lx ", *stack++);
	}
	show_trace((unsigned long *)rsp);
}

void show_registers(struct pt_regs *regs)
{
	int i;
	int in_kernel = 1;
	unsigned long rsp;
#ifdef CONFIG_SMP
	/* For SMP should get the APIC id here, just to protect against corrupted GS */ 
	const int cpu = smp_processor_id(); 
#else
	const int cpu = 0;
#endif	
	struct task_struct *cur = cpu_pda[cpu].pcurrent; 

	rsp = (unsigned long) (&regs->rsp);
	if (regs->rsp < TASK_SIZE) {
		in_kernel = 0;
		rsp = regs->rsp;
	}
	printk("CPU %d ", cpu);
	show_regs(regs);
	printk("Process %s (pid: %d, stackpage=%08lx)\n",
		cur->comm, cur->pid, 4096+(unsigned long)cur);

	/*
	 * When in-kernel, we also print out the stack and code at the
	 * time of the fault..
	 */
	if (in_kernel) {

		printk("Stack: ");
		show_stack((unsigned long*)rsp);

		printk("\nCode: ");
		if(regs->rip < PAGE_OFFSET)
			goto bad;

		for(i=0;i<20;i++)
		{
			unsigned char c;
			if(__get_user(c, &((unsigned char*)regs->rip)[i])) {
bad:
				printk(" Bad RIP value.");
				break;
			}
			printk("%02x ", c);
		}
	}
	printk("\n");
}	

void handle_BUG(struct pt_regs *regs)
{ 
	struct bug_frame f;
	char tmp;

	if (regs->cs & 3)
		return; 
	if (__copy_from_user(&f, (struct bug_frame *) regs->rip, 
			     sizeof(struct bug_frame)))
		return; 
	if ((unsigned long)f.filename < __PAGE_OFFSET || 
	    f.ud2[0] != 0x0f || f.ud2[1] != 0x0b) 
		return;
	if (__get_user(tmp, f.filename))
		f.filename = "unmapped filename"; 
	printk(KERN_EMERG "Kernel BUG at %.50s:%d\n", f.filename, f.line); 	
} 

spinlock_t die_lock = SPIN_LOCK_UNLOCKED;
int die_owner = -1;

void die(const char * str, struct pt_regs * regs, long err)
{
	int cpu;
	struct die_args args = { regs, str, err };
	console_verbose();
	notifier_call_chain(&die_chain,  DIE_DIE, &args); 
	bust_spinlocks(1);
	handle_BUG(regs);		
	printk(KERN_EMERG "%s: %04lx\n", str, err & 0xffff);
	cpu = smp_processor_id(); 
	/* racy, but better than risking deadlock. */ 
	__cli();
	if (!spin_trylock(&die_lock)) { 
		if (cpu == die_owner) 
			/* nested oops. should stop eventually */;
		else
			spin_lock(&die_lock); 
	}
	die_owner = cpu; 
	show_registers(regs);
	bust_spinlocks(0);
	spin_unlock_irq(&die_lock);
	notify_die(DIE_OOPS, (char *)str, regs, err);
	do_exit(SIGSEGV);
}

static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
{
	if (regs->cs == __KERNEL_CS)
		die(str, regs, err);
}

static inline unsigned long get_cr2(void)
{
	unsigned long address;

	/* get the address */
	__asm__("movq %%cr2,%0":"=r" (address));
	return address;
}

static void do_trap(int trapnr, int signr, char *str, 
		    struct pt_regs * regs, long error_code, siginfo_t *info)
{
#if defined(CONFIG_CHECKING) && defined(CONFIG_LOCAL_APIC)
	{ 
		unsigned long gs; 
		struct x8664_pda *pda = cpu_pda + hard_smp_processor_id(); 
		rdmsrl(MSR_GS_BASE, gs); 
		if (gs != (unsigned long)pda) { 
			wrmsrl(MSR_GS_BASE, pda); 
			printk("%s: wrong gs %lx expected %p\n", str, gs, pda);
		}
	}
#endif

	if ((regs->cs & 3)  != 0) { 
		struct task_struct *tsk = current;
		tsk->thread.error_code = error_code;
		tsk->thread.trap_no = trapnr;
		if (exception_trace && trapnr != 3)
			printk("%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
			       tsk->comm, tsk->pid, str,
			       regs->rip,regs->rsp,error_code); 
		if (info)
			force_sig_info(signr, info, tsk);
		else
			force_sig(signr, tsk);
		return;
	}


	/* kernel trap */ 
	{	     
		unsigned long fixup = search_exception_table(regs->rip);
		if (fixup) {
			extern int exception_trace; 
			if (0 && exception_trace)
	       printk(KERN_ERR
	             "%s: fixed kernel exception at %lx err:%ld\n",
	             current->comm, regs->rip, error_code);
		
			regs->rip = fixup;
		} else	
			die(str, regs, error_code);
		return;
	}
}

#define DO_ERROR(trapnr, signr, str, name) \
asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
{ \
	do_trap(trapnr, signr, str, regs, error_code, NULL); \
}