75 lines
1.9 KiB
C
75 lines
1.9 KiB
C
/*
|
|
* Derived from arch/ppc/mm/extable.c and arch/i386/mm/extable.c.
|
|
*
|
|
* Copyright (C) 2004 Paul Mackerras, IBM Corp.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/sort.h>
|
|
#include <asm/uaccess.h>
|
|
|
|
#ifndef ARCH_HAS_SORT_EXTABLE
|
|
/*
|
|
* The exception table needs to be sorted so that the binary
|
|
* search that we use to find entries in it works properly.
|
|
* This is used both for the kernel exception table and for
|
|
* the exception tables of modules that get loaded.
|
|
*/
|
|
static int cmp_ex(const void *a, const void *b)
|
|
{
|
|
const struct exception_table_entry *x = a, *y = b;
|
|
|
|
/* avoid overflow */
|
|
if (x->insn > y->insn)
|
|
return 1;
|
|
if (x->insn < y->insn)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
void sort_extable(struct exception_table_entry *start,
|
|
struct exception_table_entry *finish)
|
|
{
|
|
sort(start, finish - start, sizeof(struct exception_table_entry),
|
|
cmp_ex, NULL);
|
|
}
|
|
#endif
|
|
|
|
#ifndef ARCH_HAS_SEARCH_EXTABLE
|
|
/*
|
|
* Search one exception table for an entry corresponding to the
|
|
* given instruction address, and return the address of the entry,
|
|
* or NULL if none is found.
|
|
* We use a binary search, and thus we assume that the table is
|
|
* already sorted.
|
|
*/
|
|
const struct exception_table_entry *
|
|
search_extable(const struct exception_table_entry *first,
|
|
const struct exception_table_entry *last,
|
|
unsigned long value)
|
|
{
|
|
while (first <= last) {
|
|
const struct exception_table_entry *mid;
|
|
|
|
mid = ((last - first) >> 1) + first;
|
|
/*
|
|
* careful, the distance between value and insn
|
|
* can be larger than MAX_LONG:
|
|
*/
|
|
if (mid->insn < value)
|
|
first = mid + 1;
|
|
else if (mid->insn > value)
|
|
last = mid - 1;
|
|
else
|
|
return mid;
|
|
}
|
|
return NULL;
|
|
}
|
|
#endif
|