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81 lines
2.1 KiB
C
81 lines
2.1 KiB
C
/*
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* lib/extable.c
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* Derived from arch/ppc/mm/extable.c and arch/i386/mm/extable.c.
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*
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* Copyright (C) 2004 Paul Mackerras, IBM Corp.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <asm/uaccess.h>
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extern struct exception_table_entry __start___ex_table[];
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extern struct exception_table_entry __stop___ex_table[];
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#ifndef ARCH_HAS_SORT_EXTABLE
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/*
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* The exception table needs to be sorted so that the binary
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* search that we use to find entries in it works properly.
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* This is used both for the kernel exception table and for
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* the exception tables of modules that get loaded.
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*/
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void sort_extable(struct exception_table_entry *start,
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struct exception_table_entry *finish)
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{
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struct exception_table_entry el, *p, *q;
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/* insertion sort */
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for (p = start + 1; p < finish; ++p) {
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/* start .. p-1 is sorted */
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if (p[0].insn < p[-1].insn) {
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/* move element p down to its right place */
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el = *p;
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q = p;
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do {
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/* el comes before q[-1], move q[-1] up one */
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q[0] = q[-1];
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--q;
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} while (q > start && el.insn < q[-1].insn);
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*q = el;
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}
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}
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}
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#endif
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#ifndef ARCH_HAS_SEARCH_EXTABLE
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/*
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* Search one exception table for an entry corresponding to the
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* given instruction address, and return the address of the entry,
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* or NULL if none is found.
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* We use a binary search, and thus we assume that the table is
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* already sorted.
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*/
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const struct exception_table_entry *
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search_extable(const struct exception_table_entry *first,
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const struct exception_table_entry *last,
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unsigned long value)
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{
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while (first <= last) {
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const struct exception_table_entry *mid;
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mid = (last - first) / 2 + first;
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/*
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* careful, the distance between entries can be
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* larger than 2GB:
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*/
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if (mid->insn < value)
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first = mid + 1;
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else if (mid->insn > value)
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last = mid - 1;
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else
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return mid;
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}
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return NULL;
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}
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#endif
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