mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 08:19:28 +00:00
80 lines
2.1 KiB
C
80 lines
2.1 KiB
C
![]() |
/*
|
||
|
* lib/extable.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/config.h>
|
||
|
#include <linux/module.h>
|
||
|
#include <linux/init.h>
|
||
|
#include <linux/sort.h>
|
||
|
#include <asm/uaccess.h>
|
||
|
|
||
|
extern struct exception_table_entry __start___ex_table[];
|
||
|
extern struct exception_table_entry __stop___ex_table[];
|
||
|
|
||
|
#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) / 2 + first;
|
||
|
/*
|
||
|
* careful, the distance between entries can be
|
||
|
* larger than 2GB:
|
||
|
*/
|
||
|
if (mid->insn < value)
|
||
|
first = mid + 1;
|
||
|
else if (mid->insn > value)
|
||
|
last = mid - 1;
|
||
|
else
|
||
|
return mid;
|
||
|
}
|
||
|
return NULL;
|
||
|
}
|
||
|
#endif
|