366 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2#include <string.h>3#include <objtool/check.h>4#include <objtool/warn.h>5#include <asm/inst.h>6#include <asm/orc_types.h>7#include <linux/objtool_types.h>8 9#ifndef EM_LOONGARCH10#define EM_LOONGARCH 25811#endif12 13int arch_ftrace_match(char *name)14{15 return !strcmp(name, "_mcount");16}17 18unsigned long arch_jump_destination(struct instruction *insn)19{20 return insn->offset + (insn->immediate << 2);21}22 23unsigned long arch_dest_reloc_offset(int addend)24{25 return addend;26}27 28bool arch_pc_relative_reloc(struct reloc *reloc)29{30 return false;31}32 33bool arch_callee_saved_reg(unsigned char reg)34{35 switch (reg) {36 case CFI_RA:37 case CFI_FP:38 case CFI_S0 ... CFI_S8:39 return true;40 default:41 return false;42 }43}44 45int arch_decode_hint_reg(u8 sp_reg, int *base)46{47 switch (sp_reg) {48 case ORC_REG_UNDEFINED:49 *base = CFI_UNDEFINED;50 break;51 case ORC_REG_SP:52 *base = CFI_SP;53 break;54 case ORC_REG_FP:55 *base = CFI_FP;56 break;57 default:58 return -1;59 }60 61 return 0;62}63 64static bool is_loongarch(const struct elf *elf)65{66 if (elf->ehdr.e_machine == EM_LOONGARCH)67 return true;68 69 WARN("unexpected ELF machine type %d", elf->ehdr.e_machine);70 return false;71}72 73#define ADD_OP(op) \74 if (!(op = calloc(1, sizeof(*op)))) \75 return -1; \76 else for (*ops_list = op, ops_list = &op->next; op; op = NULL)77 78static bool decode_insn_reg0i26_fomat(union loongarch_instruction inst,79 struct instruction *insn)80{81 switch (inst.reg0i26_format.opcode) {82 case b_op:83 insn->type = INSN_JUMP_UNCONDITIONAL;84 insn->immediate = sign_extend64(inst.reg0i26_format.immediate_h << 16 |85 inst.reg0i26_format.immediate_l, 25);86 break;87 case bl_op:88 insn->type = INSN_CALL;89 insn->immediate = sign_extend64(inst.reg0i26_format.immediate_h << 16 |90 inst.reg0i26_format.immediate_l, 25);91 break;92 default:93 return false;94 }95 96 return true;97}98 99static bool decode_insn_reg1i21_fomat(union loongarch_instruction inst,100 struct instruction *insn)101{102 switch (inst.reg1i21_format.opcode) {103 case beqz_op:104 case bnez_op:105 case bceqz_op:106 insn->type = INSN_JUMP_CONDITIONAL;107 insn->immediate = sign_extend64(inst.reg1i21_format.immediate_h << 16 |108 inst.reg1i21_format.immediate_l, 20);109 break;110 default:111 return false;112 }113 114 return true;115}116 117static bool decode_insn_reg2i12_fomat(union loongarch_instruction inst,118 struct instruction *insn,119 struct stack_op **ops_list,120 struct stack_op *op)121{122 switch (inst.reg2i12_format.opcode) {123 case addid_op:124 if ((inst.reg2i12_format.rd == CFI_SP) || (inst.reg2i12_format.rj == CFI_SP)) {125 /* addi.d sp,sp,si12 or addi.d fp,sp,si12 or addi.d sp,fp,si12 */126 insn->immediate = sign_extend64(inst.reg2i12_format.immediate, 11);127 ADD_OP(op) {128 op->src.type = OP_SRC_ADD;129 op->src.reg = inst.reg2i12_format.rj;130 op->src.offset = insn->immediate;131 op->dest.type = OP_DEST_REG;132 op->dest.reg = inst.reg2i12_format.rd;133 }134 }135 if ((inst.reg2i12_format.rd == CFI_SP) && (inst.reg2i12_format.rj == CFI_FP)) {136 /* addi.d sp,fp,si12 */137 struct symbol *func = find_func_containing(insn->sec, insn->offset);138 139 if (!func)140 return false;141 142 func->frame_pointer = true;143 }144 break;145 case ldd_op:146 if (inst.reg2i12_format.rj == CFI_SP) {147 /* ld.d rd,sp,si12 */148 insn->immediate = sign_extend64(inst.reg2i12_format.immediate, 11);149 ADD_OP(op) {150 op->src.type = OP_SRC_REG_INDIRECT;151 op->src.reg = CFI_SP;152 op->src.offset = insn->immediate;153 op->dest.type = OP_DEST_REG;154 op->dest.reg = inst.reg2i12_format.rd;155 }156 }157 break;158 case std_op:159 if (inst.reg2i12_format.rj == CFI_SP) {160 /* st.d rd,sp,si12 */161 insn->immediate = sign_extend64(inst.reg2i12_format.immediate, 11);162 ADD_OP(op) {163 op->src.type = OP_SRC_REG;164 op->src.reg = inst.reg2i12_format.rd;165 op->dest.type = OP_DEST_REG_INDIRECT;166 op->dest.reg = CFI_SP;167 op->dest.offset = insn->immediate;168 }169 }170 break;171 case andi_op:172 if (inst.reg2i12_format.rd == 0 &&173 inst.reg2i12_format.rj == 0 &&174 inst.reg2i12_format.immediate == 0)175 /* andi r0,r0,0 */176 insn->type = INSN_NOP;177 break;178 default:179 return false;180 }181 182 return true;183}184 185static bool decode_insn_reg2i14_fomat(union loongarch_instruction inst,186 struct instruction *insn,187 struct stack_op **ops_list,188 struct stack_op *op)189{190 switch (inst.reg2i14_format.opcode) {191 case ldptrd_op:192 if (inst.reg2i14_format.rj == CFI_SP) {193 /* ldptr.d rd,sp,si14 */194 insn->immediate = sign_extend64(inst.reg2i14_format.immediate, 13);195 ADD_OP(op) {196 op->src.type = OP_SRC_REG_INDIRECT;197 op->src.reg = CFI_SP;198 op->src.offset = insn->immediate;199 op->dest.type = OP_DEST_REG;200 op->dest.reg = inst.reg2i14_format.rd;201 }202 }203 break;204 case stptrd_op:205 if (inst.reg2i14_format.rj == CFI_SP) {206 /* stptr.d ra,sp,0 */207 if (inst.reg2i14_format.rd == LOONGARCH_GPR_RA &&208 inst.reg2i14_format.immediate == 0)209 break;210 211 /* stptr.d rd,sp,si14 */212 insn->immediate = sign_extend64(inst.reg2i14_format.immediate, 13);213 ADD_OP(op) {214 op->src.type = OP_SRC_REG;215 op->src.reg = inst.reg2i14_format.rd;216 op->dest.type = OP_DEST_REG_INDIRECT;217 op->dest.reg = CFI_SP;218 op->dest.offset = insn->immediate;219 }220 }221 break;222 default:223 return false;224 }225 226 return true;227}228 229static bool decode_insn_reg2i16_fomat(union loongarch_instruction inst,230 struct instruction *insn)231{232 switch (inst.reg2i16_format.opcode) {233 case jirl_op:234 if (inst.reg2i16_format.rd == 0 &&235 inst.reg2i16_format.rj == CFI_RA &&236 inst.reg2i16_format.immediate == 0) {237 /* jirl r0,ra,0 */238 insn->type = INSN_RETURN;239 } else if (inst.reg2i16_format.rd == CFI_RA) {240 /* jirl ra,rj,offs16 */241 insn->type = INSN_CALL_DYNAMIC;242 } else if (inst.reg2i16_format.rd == CFI_A0 &&243 inst.reg2i16_format.immediate == 0) {244 /*245 * jirl a0,t0,0246 * this is a special case in loongarch_suspend_enter,247 * just treat it as a call instruction.248 */249 insn->type = INSN_CALL_DYNAMIC;250 } else if (inst.reg2i16_format.rd == 0 &&251 inst.reg2i16_format.immediate == 0) {252 /* jirl r0,rj,0 */253 insn->type = INSN_JUMP_DYNAMIC;254 } else if (inst.reg2i16_format.rd == 0 &&255 inst.reg2i16_format.immediate != 0) {256 /*257 * jirl r0,t0,12258 * this is a rare case in JUMP_VIRT_ADDR,259 * just ignore it due to it is harmless for tracing.260 */261 break;262 } else {263 /* jirl rd,rj,offs16 */264 insn->type = INSN_JUMP_UNCONDITIONAL;265 insn->immediate = sign_extend64(inst.reg2i16_format.immediate, 15);266 }267 break;268 case beq_op:269 case bne_op:270 case blt_op:271 case bge_op:272 case bltu_op:273 case bgeu_op:274 insn->type = INSN_JUMP_CONDITIONAL;275 insn->immediate = sign_extend64(inst.reg2i16_format.immediate, 15);276 break;277 default:278 return false;279 }280 281 return true;282}283 284int arch_decode_instruction(struct objtool_file *file, const struct section *sec,285 unsigned long offset, unsigned int maxlen,286 struct instruction *insn)287{288 struct stack_op **ops_list = &insn->stack_ops;289 const struct elf *elf = file->elf;290 struct stack_op *op = NULL;291 union loongarch_instruction inst;292 293 if (!is_loongarch(elf))294 return -1;295 296 if (maxlen < LOONGARCH_INSN_SIZE)297 return 0;298 299 insn->len = LOONGARCH_INSN_SIZE;300 insn->type = INSN_OTHER;301 insn->immediate = 0;302 303 inst = *(union loongarch_instruction *)(sec->data->d_buf + offset);304 305 if (decode_insn_reg0i26_fomat(inst, insn))306 return 0;307 if (decode_insn_reg1i21_fomat(inst, insn))308 return 0;309 if (decode_insn_reg2i12_fomat(inst, insn, ops_list, op))310 return 0;311 if (decode_insn_reg2i14_fomat(inst, insn, ops_list, op))312 return 0;313 if (decode_insn_reg2i16_fomat(inst, insn))314 return 0;315 316 if (inst.word == 0)317 insn->type = INSN_NOP;318 else if (inst.reg0i15_format.opcode == break_op) {319 /* break */320 insn->type = INSN_BUG;321 } else if (inst.reg2_format.opcode == ertn_op) {322 /* ertn */323 insn->type = INSN_RETURN;324 }325 326 return 0;327}328 329const char *arch_nop_insn(int len)330{331 static u32 nop;332 333 if (len != LOONGARCH_INSN_SIZE)334 WARN("invalid NOP size: %d\n", len);335 336 nop = LOONGARCH_INSN_NOP;337 338 return (const char *)&nop;339}340 341const char *arch_ret_insn(int len)342{343 static u32 ret;344 345 if (len != LOONGARCH_INSN_SIZE)346 WARN("invalid RET size: %d\n", len);347 348 emit_jirl((union loongarch_instruction *)&ret, LOONGARCH_GPR_RA, LOONGARCH_GPR_ZERO, 0);349 350 return (const char *)&ret;351}352 353void arch_initial_func_cfi_state(struct cfi_init_state *state)354{355 int i;356 357 for (i = 0; i < CFI_NUM_REGS; i++) {358 state->regs[i].base = CFI_UNDEFINED;359 state->regs[i].offset = 0;360 }361 362 /* initial CFA (call frame address) */363 state->cfa.base = CFI_SP;364 state->cfa.offset = 0;365}366