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-rw-r--r--tools/objtool/special.c128
1 files changed, 52 insertions, 76 deletions
diff --git a/tools/objtool/special.c b/tools/objtool/special.c
index 50af4e1274b3..2a533afbc69a 100644
--- a/tools/objtool/special.c
+++ b/tools/objtool/special.c
@@ -1,18 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
- *
- * 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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
/*
@@ -23,25 +11,10 @@
#include <stdlib.h>
#include <string.h>
-#include "special.h"
-#include "warn.h"
-
-#define EX_ENTRY_SIZE 12
-#define EX_ORIG_OFFSET 0
-#define EX_NEW_OFFSET 4
-
-#define JUMP_ENTRY_SIZE 16
-#define JUMP_ORIG_OFFSET 0
-#define JUMP_NEW_OFFSET 4
-
-#define ALT_ENTRY_SIZE 13
-#define ALT_ORIG_OFFSET 0
-#define ALT_NEW_OFFSET 4
-#define ALT_FEATURE_OFFSET 8
-#define ALT_ORIG_LEN_OFFSET 10
-#define ALT_NEW_LEN_OFFSET 11
-
-#define X86_FEATURE_POPCNT (4*32+23)
+#include <arch/special.h>
+#include <objtool/builtin.h>
+#include <objtool/special.h>
+#include <objtool/warn.h>
struct special_entry {
const char *sec;
@@ -49,9 +22,10 @@ struct special_entry {
unsigned char size, orig, new;
unsigned char orig_len, new_len; /* group only */
unsigned char feature; /* ALTERNATIVE macro CPU feature */
+ unsigned char key; /* jump_label key */
};
-struct special_entry entries[] = {
+static const struct special_entry entries[] = {
{
.sec = ".altinstructions",
.group = true,
@@ -68,6 +42,7 @@ struct special_entry entries[] = {
.size = JUMP_ENTRY_SIZE,
.orig = JUMP_ORIG_OFFSET,
.new = JUMP_NEW_OFFSET,
+ .key = JUMP_KEY_OFFSET,
},
{
.sec = "__ex_table",
@@ -78,11 +53,22 @@ struct special_entry entries[] = {
{},
};
-static int get_alt_entry(struct elf *elf, struct special_entry *entry,
+void __weak arch_handle_alternative(struct special_alt *alt)
+{
+}
+
+static void reloc_to_sec_off(struct reloc *reloc, struct section **sec,
+ unsigned long *off)
+{
+ *sec = reloc->sym->sec;
+ *off = reloc->sym->offset + reloc_addend(reloc);
+}
+
+static int get_alt_entry(struct elf *elf, const struct special_entry *entry,
struct section *sec, int idx,
struct special_alt *alt)
{
- struct rela *orig_rela, *new_rela;
+ struct reloc *orig_reloc, *new_reloc;
unsigned long offset;
offset = idx * entry->size;
@@ -95,53 +81,45 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
entry->orig_len);
alt->new_len = *(unsigned char *)(sec->data->d_buf + offset +
entry->new_len);
+ alt->feature = *(unsigned int *)(sec->data->d_buf + offset +
+ entry->feature);
}
- if (entry->feature) {
- unsigned short feature;
-
- feature = *(unsigned short *)(sec->data->d_buf + offset +
- entry->feature);
-
- /*
- * It has been requested that we don't validate the !POPCNT
- * feature path which is a "very very small percentage of
- * machines".
- */
- if (feature == X86_FEATURE_POPCNT)
- alt->skip_orig = true;
- }
-
- orig_rela = find_rela_by_dest(sec, offset + entry->orig);
- if (!orig_rela) {
- WARN_FUNC("can't find orig rela", sec, offset + entry->orig);
- return -1;
- }
- if (orig_rela->sym->type != STT_SECTION) {
- WARN_FUNC("don't know how to handle non-section rela symbol %s",
- sec, offset + entry->orig, orig_rela->sym->name);
+ orig_reloc = find_reloc_by_dest(elf, sec, offset + entry->orig);
+ if (!orig_reloc) {
+ ERROR_FUNC(sec, offset + entry->orig, "can't find orig reloc");
return -1;
}
- alt->orig_sec = orig_rela->sym->sec;
- alt->orig_off = orig_rela->addend;
+ reloc_to_sec_off(orig_reloc, &alt->orig_sec, &alt->orig_off);
+
+ arch_handle_alternative(alt);
if (!entry->group || alt->new_len) {
- new_rela = find_rela_by_dest(sec, offset + entry->new);
- if (!new_rela) {
- WARN_FUNC("can't find new rela",
- sec, offset + entry->new);
+ new_reloc = find_reloc_by_dest(elf, sec, offset + entry->new);
+ if (!new_reloc) {
+ ERROR_FUNC(sec, offset + entry->new, "can't find new reloc");
return -1;
}
- alt->new_sec = new_rela->sym->sec;
- alt->new_off = (unsigned int)new_rela->addend;
+ reloc_to_sec_off(new_reloc, &alt->new_sec, &alt->new_off);
/* _ASM_EXTABLE_EX hack */
if (alt->new_off >= 0x7ffffff0)
alt->new_off -= 0x7ffffff0;
}
+ if (entry->key) {
+ struct reloc *key_reloc;
+
+ key_reloc = find_reloc_by_dest(elf, sec, offset + entry->key);
+ if (!key_reloc) {
+ ERROR_FUNC(sec, offset + entry->key, "can't find key reloc");
+ return -1;
+ }
+ alt->key_addend = reloc_addend(key_reloc);
+ }
+
return 0;
}
@@ -152,11 +130,11 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
*/
int special_get_alts(struct elf *elf, struct list_head *alts)
{
- struct special_entry *entry;
+ const struct special_entry *entry;
struct section *sec;
unsigned int nr_entries;
struct special_alt *alt;
- int idx, ret;
+ int idx;
INIT_LIST_HEAD(alts);
@@ -165,25 +143,23 @@ int special_get_alts(struct elf *elf, struct list_head *alts)
if (!sec)
continue;
- if (sec->len % entry->size != 0) {
- WARN("%s size not a multiple of %d",
- sec->name, entry->size);
+ if (sec_size(sec) % entry->size != 0) {
+ ERROR("%s size not a multiple of %d", sec->name, entry->size);
return -1;
}
- nr_entries = sec->len / entry->size;
+ nr_entries = sec_size(sec) / entry->size;
for (idx = 0; idx < nr_entries; idx++) {
alt = malloc(sizeof(*alt));
if (!alt) {
- WARN("malloc failed");
+ ERROR_GLIBC("malloc failed");
return -1;
}
memset(alt, 0, sizeof(*alt));
- ret = get_alt_entry(elf, entry, sec, idx, alt);
- if (ret)
- return ret;
+ if (get_alt_entry(elf, entry, sec, idx, alt))
+ return -1;
list_add_tail(&alt->list, alts);
}
generated by cgit (git 2.34.1) at 2025-12-24 20:48:17 +0000