/* * 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 <linux/uaccess.h>#ifndef ARCH_HAS_RELATIVE_EXTABLE#define ex_to_insn(x) ((x)->insn)#elsestatic inline unsigned long ex_to_insn(const struct exception_table_entry *x){ return (unsigned long)&x->insn + x->insn;}#endif#ifndef ARCH_HAS_SORT_EXTABLE#ifndef ARCH_HAS_RELATIVE_EXTABLE#define swap_ex NULL#elsestatic void swap_ex(void *a, void *b, int size){ struct exception_table_entry *x = a, *y = b, tmp; int delta = b - a; tmp = *x; x->insn = y->insn + delta; y->insn = tmp.insn - delta;#ifdef swap_ex_entry_fixup swap_ex_entry_fixup(x, y, tmp, delta);#else x->fixup = y->fixup + delta; y->fixup = tmp.fixup - delta;#endif}#endif /* ARCH_HAS_RELATIVE_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 (ex_to_insn(x) > ex_to_insn(y)) return 1; if (ex_to_insn(x) < ex_to_insn(y)) 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, swap_ex);}#ifdef CONFIG_MODULES/* * If the exception table is sorted, any referring to the module init * will be at the beginning or the end. */void trim_init_extable(struct module *m){ /*trim the beginning*/ while (m->num_exentries && within_module_init(ex_to_insn(&m->extable[0]), m)) { m->extable++; m->num_exentries--; } /*trim the end*/ while (m->num_exentries && within_module_init(ex_to_insn(&m->extable[m->num_exentries - 1]), m)) m->num_exentries--;}#endif /* CONFIG_MODULES */#endif /* !ARCH_HAS_SORT_EXTABLE */#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 (ex_to_insn(mid) < value) first = mid + 1; else if (ex_to_insn(mid) > value) last = mid - 1; else return mid; } return NULL;}#endif
/*
* 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 <linux/uaccess.h>
#ifndef ARCH_HAS_RELATIVE_EXTABLE
#define ex_to_insn(x) ((x)->insn)
#else
static inline unsigned long ex_to_insn(const struct exception_table_entry *x)
{
return (unsigned long)&x->insn + x->insn;
}
#endif
#ifndef ARCH_HAS_SORT_EXTABLE
#ifndef ARCH_HAS_RELATIVE_EXTABLE
#define swap_ex NULL
#else
static void swap_ex(void *a, void *b, int size)
{
struct exception_table_entry *x = a, *y = b, tmp;
int delta = b - a;
tmp = *x;
x->insn = y->insn + delta;
y->insn = tmp.insn - delta;
#ifdef swap_ex_entry_fixup
swap_ex_entry_fixup(x, y, tmp, delta);
#else
x->fixup = y->fixup + delta;
y->fixup = tmp.fixup - delta;
#endif
}
#endif /* ARCH_HAS_RELATIVE_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 (ex_to_insn(x) > ex_to_insn(y))
return 1;
if (ex_to_insn(x) < ex_to_insn(y))
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, swap_ex);
}
#ifdef CONFIG_MODULES
/*
* If the exception table is sorted, any referring to the module init
* will be at the beginning or the end.
*/
void trim_init_extable(struct module *m)
{
/*trim the beginning*/
while (m->num_exentries &&
within_module_init(ex_to_insn(&m->extable[0]), m)) {
m->extable++;
m->num_exentries--;
}
/*trim the end*/
while (m->num_exentries &&
within_module_init(ex_to_insn(&m->extable[m->num_exentries - 1]),
m))
m->num_exentries--;
}
#endif /* CONFIG_MODULES */
#endif /* !ARCH_HAS_SORT_EXTABLE */
#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 (ex_to_insn(mid) < value)
first = mid + 1;
else if (ex_to_insn(mid) > value)
last = mid - 1;
else
return mid;
}
return NULL;
}
#endif