traps.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 903 行 · 第 1/2 页

/*
 *  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 1.36 2002/03/24 11:09:10 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 <linux/moduleparam.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/kdebug.h>
#include <asm/processor.h>

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

#include <linux/irq.h>

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);

struct notifier_block *die_chain;

static inline void conditional_sti(struct pt_regs *regs)
{
	if (regs->eflags & X86_EFLAGS_IF)
		local_irq_enable();
}

static int kstack_depth_to_print = 10;

#ifdef CONFIG_KALLSYMS
#include <linux/kallsyms.h> 
int printk_address(unsigned long address)
{ 
	unsigned long offset = 0, symsize;
	const char *symname;
	char *modname;
	char *delim = ":"; 
	char namebuf[128];

	symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf); 
	if (!symname) 
		return printk("[<%016lx>]", address);
	if (!modname) 
		modname = delim = ""; 		
        return printk("<%016lx>{%s%s%s%s%+ld}",
		      address,delim,modname,delim,symname,offset); 
} 
#else
int printk_address(unsigned long address)
{ 
	return printk("[<%016lx>]", address);
} 
#endif

unsigned long *in_exception_stack(int cpu, unsigned long stack) 
{ 
	int k;
	for (k = 0; k < N_EXCEPTION_STACKS; k++) {
		struct tss_struct *tss = &per_cpu(init_tss, cpu);
		unsigned long end = tss->ist[k] + EXCEPTION_STKSZ;

		if (stack >= tss->ist[k]  && stack <= end)
			return (unsigned long *)end;
	}
	return NULL;
} 

/*
 * x86-64 can have upto three kernel stacks: 
 * process stack
 * interrupt stack
 * severe exception (double fault, nmi, stack fault) hardware stack
 * Check and process them in order.
 */

void show_trace(unsigned long *stack)
{
	unsigned long addr;
	unsigned long *irqstack, *irqstack_end, *estack_end;
	const int cpu = safe_smp_processor_id();
	int i;

	printk("\nCall Trace:");
	i = 0; 
	
	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;
				}
			}
		}
		i += 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 + 64);

	if (stack >= irqstack && stack < irqstack_end) {
		printk("<IRQ> ");  
		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]);
		printk(" <EOI> ");
		i += 7;
	} 

	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_stack(struct task_struct *tsk, unsigned long * rsp)
{
	unsigned long *stack;
	int i;
	const int cpu = safe_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, NULL);" prints the
	// back trace for this cpu.

	if (rsp == NULL) {
		if (tsk)
			rsp = (unsigned long *)tsk->thread.rsp;
		else
			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);
}

/*
 * The architecture-independent dump_stack generator
 */
void dump_stack(void)
{
	unsigned long dummy;
	show_trace(&dummy);
}

EXPORT_SYMBOL(dump_stack);

void show_registers(struct pt_regs *regs)
{
	int i;
	int in_kernel = (regs->cs & 3) == 0;
	unsigned long rsp;
	const int cpu = safe_smp_processor_id(); 
	struct task_struct *cur = cpu_pda[cpu].pcurrent; 

		rsp = regs->rsp;

	printk("CPU %d ", cpu);
	__show_regs(regs);
	printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
		cur->comm, cur->pid, cur->thread_info, 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(NULL, (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("----------- [cut here ] --------- [please bite here ] ---------\n");
	printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", f.filename, f.line);
} 

void out_of_line_bug(void)
{ 
	BUG(); 
} 

static spinlock_t die_lock = SPIN_LOCK_UNLOCKED;
static int die_owner = -1;

void oops_begin(void)
{
	int cpu = safe_smp_processor_id(); 
	/* racy, but better than risking deadlock. */ 
	local_irq_disable();
	if (!spin_trylock(&die_lock)) { 
		if (cpu == die_owner) 
			/* nested oops. should stop eventually */;
		else
			spin_lock(&die_lock); 
	}
	die_owner = cpu; 
	console_verbose();
	bust_spinlocks(1); 
}

void oops_end(void)
{ 
	die_owner = -1;
	bust_spinlocks(0); 
	spin_unlock(&die_lock); 
	local_irq_enable();	/* make sure back scroll still works */
	if (panic_on_oops)
		panic("Oops"); 
} 

void __die(const char * str, struct pt_regs * regs, long err)
{
	static int die_counter;
	printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
#ifdef CONFIG_PREEMPT
	printk("PREEMPT ");
#endif
#ifdef CONFIG_SMP
	printk("SMP ");
#endif
#ifdef CONFIG_DEBUG_PAGEALLOC
	printk("DEBUG_PAGEALLOC");
#endif
	printk("\n");
	notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
	show_registers(regs);
	/* Executive summary in case the oops scrolled away */
	printk(KERN_ALERT "RIP ");
	printk_address(regs->rip); 
	printk(" RSP <%016lx>\n", regs->rsp); 
}

void die(const char * str, struct pt_regs * regs, long err)
{
	oops_begin();
	handle_BUG(regs);
	__die(str, regs, err);
	oops_end();
	do_exit(SIGSEGV); 
}
static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
{
	if (!(regs->eflags & VM_MASK) && (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)
{
	conditional_sti(regs);

#ifdef CONFIG_CHECKING
       { 
               unsigned long gs; 
               struct x8664_pda *pda = cpu_pda + safe_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 rip %lx\n", str, gs, pda,
			      regs->rip);
               }
       }
#endif

	if ((regs->cs & 3)  != 0) { 
		struct task_struct *tsk = current;

		if (exception_trace && unhandled_signal(tsk, signr))
			printk(KERN_INFO
			       "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
			       tsk->comm, tsk->pid, str,
			       regs->rip,regs->rsp,error_code); 

		tsk->thread.error_code = error_code;
		tsk->thread.trap_no = trapnr;
		if (info)
			force_sig_info(signr, info, tsk);
		else
			force_sig(signr, tsk);
		return;
	}


	/* kernel trap */ 
	{	     
		const struct exception_table_entry *fixup;
		fixup = search_exception_tables(regs->rip);
		if (fixup) {
			regs->rip = fixup->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) \
{ \
	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
							== NOTIFY_STOP) \
		return; \
	do_trap(trapnr, signr, str, regs, error_code, NULL); \
}

#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
{ \
	siginfo_t info; \
	info.si_signo = signr; \
	info.si_errno = 0; \
	info.si_code = sicode; \