108 lines
2.2 KiB
C
108 lines
2.2 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/arch/sparc/mm/extable.c
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*/
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#include <linux/module.h>
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#include <linux/extable.h>
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#include <linux/uaccess.h>
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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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}
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/* Caller knows they are in a range if ret->fixup == 0 */
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const struct exception_table_entry *
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search_extable(const struct exception_table_entry *base,
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const size_t num,
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unsigned long value)
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{
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int i;
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/* Single insn entries are encoded as:
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* word 1: insn address
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* word 2: fixup code address
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*
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* Range entries are encoded as:
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* word 1: first insn address
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* word 2: 0
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* word 3: last insn address + 4 bytes
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* word 4: fixup code address
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*
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* Deleted entries are encoded as:
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* word 1: unused
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* word 2: -1
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*
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* See asm/uaccess.h for more details.
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*/
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/* 1. Try to find an exact match. */
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for (i = 0; i < num; i++) {
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if (base[i].fixup == 0) {
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/* A range entry, skip both parts. */
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i++;
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continue;
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}
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/* A deleted entry; see trim_init_extable */
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if (base[i].fixup == -1)
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continue;
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if (base[i].insn == value)
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return &base[i];
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}
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/* 2. Try to find a range match. */
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for (i = 0; i < (num - 1); i++) {
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if (base[i].fixup)
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continue;
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if (base[i].insn <= value && base[i + 1].insn > value)
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return &base[i];
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i++;
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}
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return NULL;
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}
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#ifdef CONFIG_MODULES
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/* We could memmove them around; easier to mark the trimmed ones. */
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void trim_init_extable(struct module *m)
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{
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unsigned int i;
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bool range;
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for (i = 0; i < m->num_exentries; i += range ? 2 : 1) {
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range = m->extable[i].fixup == 0;
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if (within_module_init(m->extable[i].insn, m)) {
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m->extable[i].fixup = -1;
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if (range)
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m->extable[i+1].fixup = -1;
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}
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if (range)
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i++;
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}
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}
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#endif /* CONFIG_MODULES */
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/* Special extable search, which handles ranges. Returns fixup */
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unsigned long search_extables_range(unsigned long addr, unsigned long *g2)
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{
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const struct exception_table_entry *entry;
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entry = search_exception_tables(addr);
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if (!entry)
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return 0;
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/* Inside range? Fix g2 and return correct fixup */
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if (!entry->fixup) {
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*g2 = (addr - entry->insn) / 4;
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return (entry + 1)->fixup;
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}
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return entry->fixup;
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}
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