arch/mips64/mm/extable.c

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1994, 1995, 1996, 1999 by Ralf Baechle
 * Copyright (C) 1999 by Silicon Graphics
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>

extern const struct exception_table_entry __start___ex_table[];
extern const struct exception_table_entry __stop___ex_table[];

static inline unsigned long
search_one_table(const struct exception_table_entry *first,
                 const struct exception_table_entry *last,
                 unsigned long value)
{
	while (first <= last) {
		const struct exception_table_entry *mid;
		long diff;

		mid = (last - first) / 2 + first;
		diff = mid->insn - value;
		if (diff == 0)
			return mid->nextinsn;
		else if (diff < 0)
			first = mid+1;
		else
			last = mid-1;
	}
	return 0;
}

extern spinlock_t modlist_lock;

unsigned long search_exception_table(unsigned long addr)
{
	unsigned long ret = 0;
	unsigned long flags;
	
#ifndef CONFIG_MODULES
	/* There is only the kernel to search.  */
	ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr);
	return ret;
#else
	/* The kernel is the last "module" -- no need to treat it special.  */
	struct module *mp;

	spin_lock_irqsave(&modlist_lock, flags);
	for (mp = module_list; mp != NULL; mp = mp->next) {
		if (mp->ex_table_start == NULL)
			continue;
		ret = search_one_table(mp->ex_table_start,
				       mp->ex_table_end - 1, addr);
		if (ret)
			break;
	}
	spin_unlock_irqrestore(&modlist_lock, flags);
	return ret;
#endif
}