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// SPDX-License-Identifier: GPL-2.0-or-later
#include <string.h>
#include <objtool/special.h>
#include <objtool/warn.h>
bool arch_support_alt_relocation(struct special_alt *special_alt,
struct instruction *insn,
struct reloc *reloc)
{
return false;
}
struct table_info {
struct list_head jump_info;
unsigned long insn_offset;
unsigned long rodata_offset;
};
static void get_rodata_table_size_by_table_annotate(struct objtool_file *file,
struct instruction *insn,
unsigned long *table_size)
{
struct section *rsec;
struct reloc *reloc;
struct list_head table_list;
struct table_info *orig_table;
struct table_info *next_table;
unsigned long tmp_insn_offset;
unsigned long tmp_rodata_offset;
rsec = find_section_by_name(file->elf, ".rela.discard.tablejump_annotate");
if (!rsec)
return;
INIT_LIST_HEAD(&table_list);
for_each_reloc(rsec, reloc) {
orig_table = malloc(sizeof(struct table_info));
if (!orig_table) {
WARN("malloc failed");
return;
}
orig_table->insn_offset = reloc->sym->offset + reloc_addend(reloc);
reloc++;
orig_table->rodata_offset = reloc->sym->offset + reloc_addend(reloc);
list_add_tail(&orig_table->jump_info, &table_list);
if (reloc_idx(reloc) + 1 == sec_num_entries(rsec))
break;
}
list_for_each_entry(orig_table, &table_list, jump_info) {
next_table = list_next_entry(orig_table, jump_info);
list_for_each_entry_from(next_table, &table_list, jump_info) {
if (next_table->rodata_offset < orig_table->rodata_offset) {
tmp_insn_offset = next_table->insn_offset;
tmp_rodata_offset = next_table->rodata_offset;
next_table->insn_offset = orig_table->insn_offset;
next_table->rodata_offset = orig_table->rodata_offset;
orig_table->insn_offset = tmp_insn_offset;
orig_table->rodata_offset = tmp_rodata_offset;
}
}
}
list_for_each_entry(orig_table, &table_list, jump_info) {
if (insn->offset == orig_table->insn_offset) {
next_table = list_next_entry(orig_table, jump_info);
if (&next_table->jump_info == &table_list) {
*table_size = 0;
return;
}
while (next_table->rodata_offset == orig_table->rodata_offset) {
next_table = list_next_entry(next_table, jump_info);
if (&next_table->jump_info == &table_list) {
*table_size = 0;
return;
}
}
*table_size = next_table->rodata_offset - orig_table->rodata_offset;
}
}
}
static struct reloc *find_reloc_by_table_annotate(struct objtool_file *file,
struct instruction *insn,
unsigned long *table_size)
{
struct section *rsec;
struct reloc *reloc;
unsigned long offset;
rsec = find_section_by_name(file->elf, ".rela.discard.tablejump_annotate");
if (!rsec)
return NULL;
for_each_reloc(rsec, reloc) {
if (reloc->sym->sec->rodata)
continue;
if (strcmp(insn->sec->name, reloc->sym->sec->name))
continue;
offset = reloc->sym->offset + reloc_addend(reloc);
if (insn->offset == offset) {
get_rodata_table_size_by_table_annotate(file, insn, table_size);
reloc++;
return reloc;
}
}
return NULL;
}
static struct reloc *find_reloc_of_rodata_c_jump_table(struct section *sec,
unsigned long offset,
unsigned long *table_size)
{
struct section *rsec;
struct reloc *reloc;
rsec = sec->rsec;
if (!rsec)
return NULL;
for_each_reloc(rsec, reloc) {
if (reloc_offset(reloc) > offset)
break;
if (!strcmp(reloc->sym->sec->name, C_JUMP_TABLE_SECTION)) {
*table_size = 0;
return reloc;
}
}
return NULL;
}
struct reloc *arch_find_switch_table(struct objtool_file *file,
struct instruction *insn,
unsigned long *table_size)
{
struct reloc *annotate_reloc;
struct reloc *rodata_reloc;
struct section *table_sec;
unsigned long table_offset;
annotate_reloc = find_reloc_by_table_annotate(file, insn, table_size);
if (!annotate_reloc) {
annotate_reloc = find_reloc_of_rodata_c_jump_table(
insn->sec, insn->offset, table_size);
if (!annotate_reloc)
return NULL;
}
table_sec = annotate_reloc->sym->sec;
table_offset = annotate_reloc->sym->offset + reloc_addend(annotate_reloc);
/*
* Each table entry has a rela associated with it. The rela
* should reference text in the same function as the original
* instruction.
*/
rodata_reloc = find_reloc_by_dest(file->elf, table_sec, table_offset);
if (!rodata_reloc)
return NULL;
return rodata_reloc;
}
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