traps.c

linux-2.4.29操作系统的源码

/*
 *  arch/s390/kernel/traps.c
 *
 *  S390 version
 *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Martin Schwidefsky ([e-mail]),
 *               Denis Joseph Barrow ([e-mail],[e-mail]),
 *
 *  Derived from "arch/i386/kernel/traps.c"
 *    Copyright (C) 1991, 1992 Linus Torvalds
 */

/*
 * '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/ptrace.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/module.h>

#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/atomic.h>
#if CONFIG_REMOTE_DEBUG
#include <asm/gdb-stub.h>
#endif
#include <asm/cpcmd.h>
#include <asm/s390_ext.h>

/* Called from entry.S only */
extern void handle_per_exception(struct pt_regs *regs);

typedef void pgm_check_handler_t(struct pt_regs *, long);
pgm_check_handler_t *pgm_check_table[128];

#ifdef CONFIG_SYSCTL
#ifdef CONFIG_PROCESS_DEBUG
int sysctl_userprocess_debug = 1;
#else
int sysctl_userprocess_debug = 0;
#endif
#endif

extern pgm_check_handler_t do_protection_exception;
extern pgm_check_handler_t do_segment_exception;
extern pgm_check_handler_t do_region_exception;
extern pgm_check_handler_t do_page_exception;
#ifdef CONFIG_PFAULT
extern int pfault_init(void);
extern void pfault_fini(void);
extern void pfault_interrupt(struct pt_regs *regs, __u16 error_code);
static ext_int_info_t ext_int_pfault;
#endif

int kstack_depth_to_print = 20;

/*
 * If the address is either in the .text section of the
 * kernel, or in the vmalloc'ed module regions, it *may* 
 * be the address of a calling routine
 */
extern char _stext, _etext;

#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

void show_trace(unsigned long * stack)
{
	unsigned long backchain, low_addr, high_addr, ret_addr;
	int i;

	if (!stack)
		stack = (unsigned long*)&stack;

	printk("Call Trace: ");
	low_addr = ((unsigned long) stack) & PSW_ADDR_MASK;
	high_addr = (low_addr & (-THREAD_SIZE)) + THREAD_SIZE;
	/* Skip the first frame (biased stack) */
	backchain = *((unsigned long *) low_addr) & PSW_ADDR_MASK;
	/* Print up to 8 lines */
	for (i = 0; i < 8; i++) {
		if (backchain < low_addr || backchain >= high_addr)
			break;
		ret_addr = *((unsigned long *) (backchain+112)) & PSW_ADDR_MASK;
		if (!kernel_text_address(ret_addr))
			break;
		if (i && ((i % 3) == 0))
			printk("\n   ");
		printk("[<%016lx>] ", ret_addr);
		low_addr = backchain;
		backchain = *((unsigned long *) backchain) & PSW_ADDR_MASK;
	}
	printk("\n");
}

void show_trace_task(struct task_struct *tsk)
{
	/*
	 * We can't print the backtrace of a running process. It is
	 * unreliable at best and can cause kernel oopses.
	 */
	if (task_has_cpu(tsk))
		return;
	show_trace((unsigned long *) tsk->thread.ksp);
}

void show_stack(unsigned long *sp)
{
	unsigned long *stack;
	int i;

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

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

	stack = sp;
	for (i = 0; i < kstack_depth_to_print; i++) {
		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
			break;
		if (i && ((i % 4) == 0))
			printk("\n       ");
		printk("%016lx ", *stack++);
	}
	printk("\n");
	show_trace(sp);
}

void show_registers(struct pt_regs *regs)
{
	mm_segment_t old_fs;
	char *mode;
	int i;

	mode = (regs->psw.mask & PSW_PROBLEM_STATE) ? "User" : "Krnl";
	printk("%s PSW : %016lx %016lx\n",
	       mode, (unsigned long) regs->psw.mask,
	       (unsigned long) regs->psw.addr);
	printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
	printk("           %016lx %016lx %016lx %016lx\n",
	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
	printk("           %016lx %016lx %016lx %016lx\n",
	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
	printk("           %016lx %016lx %016lx %016lx\n",
	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
	printk("%s ACRS: %08x %08x %08x %08x\n", mode,
	       regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
	printk("           %08x %08x %08x %08x\n",
	       regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
	printk("           %08x %08x %08x %08x\n",
	       regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
	printk("           %08x %08x %08x %08x\n",
	       regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);

	/*
	 * Print the first 20 byte of the instruction stream at the
	 * time of the fault.
	 */
	old_fs = get_fs();
	if (regs->psw.mask & PSW_PROBLEM_STATE)
		set_fs(USER_DS);
	else
		set_fs(KERNEL_DS);
	printk("%s Code: ", mode);
	for (i = 0; i < 20; i++) {
		unsigned char c;
		if (__get_user(c, (char *)(regs->psw.addr + i))) {
			printk(" Bad PSW.");
			break;
		}
		printk("%02x ", c);
	}
	set_fs(old_fs);

	printk("\n");
}	

/* This is called from fs/proc/array.c */
char *task_show_regs(struct task_struct *task, char *buf)
{
	struct pt_regs *regs;

	regs = __KSTK_PTREGS(task);
	buf += sprintf(buf, "task: %016lx, ksp: %016lx\n",
		       (unsigned long) task, task->thread.ksp);
	buf += sprintf(buf, "User PSW : %016lx %016lx\n",
		       (unsigned long) regs->psw.mask, 
		       (unsigned long) regs->psw.addr);
	buf += sprintf(buf, "User GPRS: %016lx %016lx %016lx %016lx\n",
		       regs->gprs[0], regs->gprs[1],
		       regs->gprs[2], regs->gprs[3]);
	buf += sprintf(buf, "           %016lx %016lx %016lx %016lx\n",
		       regs->gprs[4], regs->gprs[5], 
		       regs->gprs[6], regs->gprs[7]);
	buf += sprintf(buf, "           %016lx %016lx %016lx %016lx\n",
		       regs->gprs[8], regs->gprs[9],
		       regs->gprs[10], regs->gprs[11]);
	buf += sprintf(buf, "           %016lx %016lx %016lx %016lx\n",
		       regs->gprs[12], regs->gprs[13],
		       regs->gprs[14], regs->gprs[15]);
	buf += sprintf(buf, "User ACRS: %08x %08x %08x %08x\n",
		       regs->acrs[0], regs->acrs[1],
		       regs->acrs[2], regs->acrs[3]);
	buf += sprintf(buf, "           %08x %08x %08x %08x\n",
		       regs->acrs[4], regs->acrs[5],
		       regs->acrs[6], regs->acrs[7]);
	buf += sprintf(buf, "           %08x %08x %08x %08x\n",
		       regs->acrs[8], regs->acrs[9],
		       regs->acrs[10], regs->acrs[11]);
	buf += sprintf(buf, "           %08x %08x %08x %08x\n",
		       regs->acrs[12], regs->acrs[13],
		       regs->acrs[14], regs->acrs[15]);
	return buf;
}

spinlock_t die_lock = SPIN_LOCK_UNLOCKED;

void die(const char * str, struct pt_regs * regs, long err)
{
        console_verbose();
        spin_lock_irq(&die_lock);
	bust_spinlocks(1);
        printk("%s: %04lx\n", str, err & 0xffff);