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// SPDX-License-Identifier: GPL-2.0-or-later
#include <string.h>
#include <objtool/check.h>
#include <objtool/warn.h>
#include <asm/inst.h>
#include <asm/orc_types.h>
#include <linux/objtool_types.h>
#ifndef EM_LOONGARCH
#define EM_LOONGARCH 258
#endif
int arch_ftrace_match(char *name)
{
return !strcmp(name, "_mcount");
}
unsigned long arch_jump_destination(struct instruction *insn)
{
return insn->offset + (insn->immediate << 2);
}
unsigned long arch_dest_reloc_offset(int addend)
{
return addend;
}
bool arch_pc_relative_reloc(struct reloc *reloc)
{
return false;
}
bool arch_callee_saved_reg(unsigned char reg)
{
switch (reg) {
case CFI_RA:
case CFI_FP:
case CFI_S0 ... CFI_S8:
return true;
default:
return false;
}
}
int arch_decode_hint_reg(u8 sp_reg, int *base)
{
switch (sp_reg) {
case ORC_REG_UNDEFINED:
*base = CFI_UNDEFINED;
break;
case ORC_REG_SP:
*base = CFI_SP;
break;
case ORC_REG_FP:
*base = CFI_FP;
break;
default:
return -1;
}
return 0;
}
static bool is_loongarch(const struct elf *elf)
{
if (elf->ehdr.e_machine == EM_LOONGARCH)
return true;
WARN("unexpected ELF machine type %d", elf->ehdr.e_machine);
return false;
}
#define ADD_OP(op) \
if (!(op = calloc(1, sizeof(*op)))) \
return -1; \
else for (*ops_list = op, ops_list = &op->next; op; op = NULL)
static bool decode_insn_reg0i26_fomat(union loongarch_instruction inst,
struct instruction *insn)
{
switch (inst.reg0i26_format.opcode) {
case b_op:
insn->type = INSN_JUMP_UNCONDITIONAL;
insn->immediate = sign_extend64(inst.reg0i26_format.immediate_h << 16 |
inst.reg0i26_format.immediate_l, 25);
break;
case bl_op:
insn->type = INSN_CALL;
insn->immediate = sign_extend64(inst.reg0i26_format.immediate_h << 16 |
inst.reg0i26_format.immediate_l, 25);
break;
default:
return false;
}
return true;
}
static bool decode_insn_reg1i21_fomat(union loongarch_instruction inst,
struct instruction *insn)
{
switch (inst.reg1i21_format.opcode) {
case beqz_op:
case bnez_op:
case bceqz_op:
insn->type = INSN_JUMP_CONDITIONAL;
insn->immediate = sign_extend64(inst.reg1i21_format.immediate_h << 16 |
inst.reg1i21_format.immediate_l, 20);
break;
default:
return false;
}
return true;
}
static bool decode_insn_reg2i12_fomat(union loongarch_instruction inst,
struct instruction *insn,
struct stack_op **ops_list,
struct stack_op *op)
{
switch (inst.reg2i12_format.opcode) {
case addid_op:
if ((inst.reg2i12_format.rd == CFI_SP) || (inst.reg2i12_format.rj == CFI_SP)) {
/* addi.d sp,sp,si12 or addi.d fp,sp,si12 or addi.d sp,fp,si12 */
insn->immediate = sign_extend64(inst.reg2i12_format.immediate, 11);
ADD_OP(op) {
op->src.type = OP_SRC_ADD;
op->src.reg = inst.reg2i12_format.rj;
op->src.offset = insn->immediate;
op->dest.type = OP_DEST_REG;
op->dest.reg = inst.reg2i12_format.rd;
}
}
if ((inst.reg2i12_format.rd == CFI_SP) && (inst.reg2i12_format.rj == CFI_FP)) {
/* addi.d sp,fp,si12 */
struct symbol *func = find_func_containing(insn->sec, insn->offset);
if (!func)
return false;
func->frame_pointer = true;
}
break;
case ldd_op:
if (inst.reg2i12_format.rj == CFI_SP) {
/* ld.d rd,sp,si12 */
insn->immediate = sign_extend64(inst.reg2i12_format.immediate, 11);
ADD_OP(op) {
op->src.type = OP_SRC_REG_INDIRECT;
op->src.reg = CFI_SP;
op->src.offset = insn->immediate;
op->dest.type = OP_DEST_REG;
op->dest.reg = inst.reg2i12_format.rd;
}
}
break;
case std_op:
if (inst.reg2i12_format.rj == CFI_SP) {
/* st.d rd,sp,si12 */
insn->immediate = sign_extend64(inst.reg2i12_format.immediate, 11);
ADD_OP(op) {
op->src.type = OP_SRC_REG;
op->src.reg = inst.reg2i12_format.rd;
op->dest.type = OP_DEST_REG_INDIRECT;
op->dest.reg = CFI_SP;
op->dest.offset = insn->immediate;
}
}
break;
case andi_op:
if (inst.reg2i12_format.rd == 0 &&
inst.reg2i12_format.rj == 0 &&
inst.reg2i12_format.immediate == 0)
/* andi r0,r0,0 */
insn->type = INSN_NOP;
break;
default:
return false;
}
return true;
}
static bool decode_insn_reg2i14_fomat(union loongarch_instruction inst,
struct instruction *insn,
struct stack_op **ops_list,
struct stack_op *op)
{
switch (inst.reg2i14_format.opcode) {
case ldptrd_op:
if (inst.reg2i14_format.rj == CFI_SP) {
/* ldptr.d rd,sp,si14 */
insn->immediate = sign_extend64(inst.reg2i14_format.immediate, 13);
ADD_OP(op) {
op->src.type = OP_SRC_REG_INDIRECT;
op->src.reg = CFI_SP;
op->src.offset = insn->immediate;
op->dest.type = OP_DEST_REG;
op->dest.reg = inst.reg2i14_format.rd;
}
}
break;
case stptrd_op:
if (inst.reg2i14_format.rj == CFI_SP) {
/* stptr.d ra,sp,0 */
if (inst.reg2i14_format.rd == LOONGARCH_GPR_RA &&
inst.reg2i14_format.immediate == 0)
break;
/* stptr.d rd,sp,si14 */
insn->immediate = sign_extend64(inst.reg2i14_format.immediate, 13);
ADD_OP(op) {
op->src.type = OP_SRC_REG;
op->src.reg = inst.reg2i14_format.rd;
op->dest.type = OP_DEST_REG_INDIRECT;
op->dest.reg = CFI_SP;
op->dest.offset = insn->immediate;
}
}
break;
default:
return false;
}
return true;
}
static bool decode_insn_reg2i16_fomat(union loongarch_instruction inst,
struct instruction *insn)
{
switch (inst.reg2i16_format.opcode) {
case jirl_op:
if (inst.reg2i16_format.rd == 0 &&
inst.reg2i16_format.rj == CFI_RA &&
inst.reg2i16_format.immediate == 0) {
/* jirl r0,ra,0 */
insn->type = INSN_RETURN;
} else if (inst.reg2i16_format.rd == CFI_RA) {
/* jirl ra,rj,offs16 */
insn->type = INSN_CALL_DYNAMIC;
} else if (inst.reg2i16_format.rd == CFI_A0 &&
inst.reg2i16_format.immediate == 0) {
/*
* jirl a0,t0,0
* this is a special case in loongarch_suspend_enter,
* just treat it as a call instruction.
*/
insn->type = INSN_CALL_DYNAMIC;
} else if (inst.reg2i16_format.rd == 0 &&
inst.reg2i16_format.immediate == 0) {
/* jirl r0,rj,0 */
insn->type = INSN_JUMP_DYNAMIC;
} else if (inst.reg2i16_format.rd == 0 &&
inst.reg2i16_format.immediate != 0) {
/*
* jirl r0,t0,12
* this is a rare case in JUMP_VIRT_ADDR,
* just ignore it due to it is harmless for tracing.
*/
break;
} else {
/* jirl rd,rj,offs16 */
insn->type = INSN_JUMP_UNCONDITIONAL;
insn->immediate = sign_extend64(inst.reg2i16_format.immediate, 15);
}
break;
case beq_op:
case bne_op:
case blt_op:
case bge_op:
case bltu_op:
case bgeu_op:
insn->type = INSN_JUMP_CONDITIONAL;
insn->immediate = sign_extend64(inst.reg2i16_format.immediate, 15);
break;
default:
return false;
}
return true;
}
int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
unsigned long offset, unsigned int maxlen,
struct instruction *insn)
{
struct stack_op **ops_list = &insn->stack_ops;
const struct elf *elf = file->elf;
struct stack_op *op = NULL;
union loongarch_instruction inst;
if (!is_loongarch(elf))
return -1;
if (maxlen < LOONGARCH_INSN_SIZE)
return 0;
insn->len = LOONGARCH_INSN_SIZE;
insn->type = INSN_OTHER;
insn->immediate = 0;
inst = *(union loongarch_instruction *)(sec->data->d_buf + offset);
if (decode_insn_reg0i26_fomat(inst, insn))
return 0;
if (decode_insn_reg1i21_fomat(inst, insn))
return 0;
if (decode_insn_reg2i12_fomat(inst, insn, ops_list, op))
return 0;
if (decode_insn_reg2i14_fomat(inst, insn, ops_list, op))
return 0;
if (decode_insn_reg2i16_fomat(inst, insn))
return 0;
if (inst.word == 0)
insn->type = INSN_NOP;
else if (inst.reg0i15_format.opcode == break_op) {
/* break */
insn->type = INSN_BUG;
} else if (inst.reg2_format.opcode == ertn_op) {
/* ertn */
insn->type = INSN_RETURN;
}
return 0;
}
const char *arch_nop_insn(int len)
{
static u32 nop;
if (len != LOONGARCH_INSN_SIZE)
WARN("invalid NOP size: %d\n", len);
nop = LOONGARCH_INSN_NOP;
return (const char *)&nop;
}
const char *arch_ret_insn(int len)
{
static u32 ret;
if (len != LOONGARCH_INSN_SIZE)
WARN("invalid RET size: %d\n", len);
emit_jirl((union loongarch_instruction *)&ret, LOONGARCH_GPR_RA, LOONGARCH_GPR_ZERO, 0);
return (const char *)&ret;
}
void arch_initial_func_cfi_state(struct cfi_init_state *state)
{
int i;
for (i = 0; i < CFI_NUM_REGS; i++) {
state->regs[i].base = CFI_UNDEFINED;
state->regs[i].offset = 0;
}
/* initial CFA (call frame address) */
state->cfa.base = CFI_SP;
state->cfa.offset = 0;
}
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