mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 10:04:12 +08:00
d0c5c4cc73
Have elf_add_reloc() create the relocation section implicitly. Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/20210326151259.880174448@infradead.org
239 lines
5.2 KiB
C
239 lines
5.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#include <linux/objtool.h>
|
|
#include <asm/orc_types.h>
|
|
|
|
#include <objtool/check.h>
|
|
#include <objtool/warn.h>
|
|
#include <objtool/endianness.h>
|
|
|
|
static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi)
|
|
{
|
|
struct instruction *insn = container_of(cfi, struct instruction, cfi);
|
|
struct cfi_reg *bp = &cfi->regs[CFI_BP];
|
|
|
|
memset(orc, 0, sizeof(*orc));
|
|
|
|
orc->end = cfi->end;
|
|
|
|
if (cfi->cfa.base == CFI_UNDEFINED) {
|
|
orc->sp_reg = ORC_REG_UNDEFINED;
|
|
return 0;
|
|
}
|
|
|
|
switch (cfi->cfa.base) {
|
|
case CFI_SP:
|
|
orc->sp_reg = ORC_REG_SP;
|
|
break;
|
|
case CFI_SP_INDIRECT:
|
|
orc->sp_reg = ORC_REG_SP_INDIRECT;
|
|
break;
|
|
case CFI_BP:
|
|
orc->sp_reg = ORC_REG_BP;
|
|
break;
|
|
case CFI_BP_INDIRECT:
|
|
orc->sp_reg = ORC_REG_BP_INDIRECT;
|
|
break;
|
|
case CFI_R10:
|
|
orc->sp_reg = ORC_REG_R10;
|
|
break;
|
|
case CFI_R13:
|
|
orc->sp_reg = ORC_REG_R13;
|
|
break;
|
|
case CFI_DI:
|
|
orc->sp_reg = ORC_REG_DI;
|
|
break;
|
|
case CFI_DX:
|
|
orc->sp_reg = ORC_REG_DX;
|
|
break;
|
|
default:
|
|
WARN_FUNC("unknown CFA base reg %d",
|
|
insn->sec, insn->offset, cfi->cfa.base);
|
|
return -1;
|
|
}
|
|
|
|
switch (bp->base) {
|
|
case CFI_UNDEFINED:
|
|
orc->bp_reg = ORC_REG_UNDEFINED;
|
|
break;
|
|
case CFI_CFA:
|
|
orc->bp_reg = ORC_REG_PREV_SP;
|
|
break;
|
|
case CFI_BP:
|
|
orc->bp_reg = ORC_REG_BP;
|
|
break;
|
|
default:
|
|
WARN_FUNC("unknown BP base reg %d",
|
|
insn->sec, insn->offset, bp->base);
|
|
return -1;
|
|
}
|
|
|
|
orc->sp_offset = cfi->cfa.offset;
|
|
orc->bp_offset = bp->offset;
|
|
orc->type = cfi->type;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int write_orc_entry(struct elf *elf, struct section *orc_sec,
|
|
struct section *ip_sec, unsigned int idx,
|
|
struct section *insn_sec, unsigned long insn_off,
|
|
struct orc_entry *o)
|
|
{
|
|
struct orc_entry *orc;
|
|
|
|
/* populate ORC data */
|
|
orc = (struct orc_entry *)orc_sec->data->d_buf + idx;
|
|
memcpy(orc, o, sizeof(*orc));
|
|
orc->sp_offset = bswap_if_needed(orc->sp_offset);
|
|
orc->bp_offset = bswap_if_needed(orc->bp_offset);
|
|
|
|
/* populate reloc for ip */
|
|
if (elf_add_reloc_to_insn(elf, ip_sec, idx * sizeof(int), R_X86_64_PC32,
|
|
insn_sec, insn_off))
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct orc_list_entry {
|
|
struct list_head list;
|
|
struct orc_entry orc;
|
|
struct section *insn_sec;
|
|
unsigned long insn_off;
|
|
};
|
|
|
|
static int orc_list_add(struct list_head *orc_list, struct orc_entry *orc,
|
|
struct section *sec, unsigned long offset)
|
|
{
|
|
struct orc_list_entry *entry = malloc(sizeof(*entry));
|
|
|
|
if (!entry) {
|
|
WARN("malloc failed");
|
|
return -1;
|
|
}
|
|
|
|
entry->orc = *orc;
|
|
entry->insn_sec = sec;
|
|
entry->insn_off = offset;
|
|
|
|
list_add_tail(&entry->list, orc_list);
|
|
return 0;
|
|
}
|
|
|
|
static unsigned long alt_group_len(struct alt_group *alt_group)
|
|
{
|
|
return alt_group->last_insn->offset +
|
|
alt_group->last_insn->len -
|
|
alt_group->first_insn->offset;
|
|
}
|
|
|
|
int orc_create(struct objtool_file *file)
|
|
{
|
|
struct section *sec, *orc_sec;
|
|
unsigned int nr = 0, idx = 0;
|
|
struct orc_list_entry *entry;
|
|
struct list_head orc_list;
|
|
|
|
struct orc_entry null = {
|
|
.sp_reg = ORC_REG_UNDEFINED,
|
|
.bp_reg = ORC_REG_UNDEFINED,
|
|
.type = UNWIND_HINT_TYPE_CALL,
|
|
};
|
|
|
|
/* Build a deduplicated list of ORC entries: */
|
|
INIT_LIST_HEAD(&orc_list);
|
|
for_each_sec(file, sec) {
|
|
struct orc_entry orc, prev_orc = {0};
|
|
struct instruction *insn;
|
|
bool empty = true;
|
|
|
|
if (!sec->text)
|
|
continue;
|
|
|
|
sec_for_each_insn(file, sec, insn) {
|
|
struct alt_group *alt_group = insn->alt_group;
|
|
int i;
|
|
|
|
if (!alt_group) {
|
|
if (init_orc_entry(&orc, &insn->cfi))
|
|
return -1;
|
|
if (!memcmp(&prev_orc, &orc, sizeof(orc)))
|
|
continue;
|
|
if (orc_list_add(&orc_list, &orc, sec,
|
|
insn->offset))
|
|
return -1;
|
|
nr++;
|
|
prev_orc = orc;
|
|
empty = false;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Alternatives can have different stack layout
|
|
* possibilities (but they shouldn't conflict).
|
|
* Instead of traversing the instructions, use the
|
|
* alt_group's flattened byte-offset-addressed CFI
|
|
* array.
|
|
*/
|
|
for (i = 0; i < alt_group_len(alt_group); i++) {
|
|
struct cfi_state *cfi = alt_group->cfi[i];
|
|
if (!cfi)
|
|
continue;
|
|
if (init_orc_entry(&orc, cfi))
|
|
return -1;
|
|
if (!memcmp(&prev_orc, &orc, sizeof(orc)))
|
|
continue;
|
|
if (orc_list_add(&orc_list, &orc, insn->sec,
|
|
insn->offset + i))
|
|
return -1;
|
|
nr++;
|
|
prev_orc = orc;
|
|
empty = false;
|
|
}
|
|
|
|
/* Skip to the end of the alt_group */
|
|
insn = alt_group->last_insn;
|
|
}
|
|
|
|
/* Add a section terminator */
|
|
if (!empty) {
|
|
orc_list_add(&orc_list, &null, sec, sec->len);
|
|
nr++;
|
|
}
|
|
}
|
|
if (!nr)
|
|
return 0;
|
|
|
|
/* Create .orc_unwind, .orc_unwind_ip and .rela.orc_unwind_ip sections: */
|
|
sec = find_section_by_name(file->elf, ".orc_unwind");
|
|
if (sec) {
|
|
WARN("file already has .orc_unwind section, skipping");
|
|
return -1;
|
|
}
|
|
orc_sec = elf_create_section(file->elf, ".orc_unwind", 0,
|
|
sizeof(struct orc_entry), nr);
|
|
if (!orc_sec)
|
|
return -1;
|
|
|
|
sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), nr);
|
|
if (!sec)
|
|
return -1;
|
|
|
|
/* Write ORC entries to sections: */
|
|
list_for_each_entry(entry, &orc_list, list) {
|
|
if (write_orc_entry(file->elf, orc_sec, sec, idx++,
|
|
entry->insn_sec, entry->insn_off,
|
|
&entry->orc))
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|