objtool: Add support for intra-function calls
[platform/kernel/linux-rpi.git] / tools / objtool / arch / x86 / decode.c
index a62e032..4b504fc 100644 (file)
@@ -11,6 +11,7 @@
 #include "../../../arch/x86/lib/inat.c"
 #include "../../../arch/x86/lib/insn.c"
 
+#include "../../check.h"
 #include "../../elf.h"
 #include "../../arch.h"
 #include "../../warn.h"
@@ -26,7 +27,7 @@ static unsigned char op_to_cfi_reg[][2] = {
        {CFI_DI, CFI_R15},
 };
 
-static int is_x86_64(struct elf *elf)
+static int is_x86_64(const struct elf *elf)
 {
        switch (elf->ehdr.e_machine) {
        case EM_X86_64:
@@ -66,16 +67,34 @@ bool arch_callee_saved_reg(unsigned char reg)
        }
 }
 
-int arch_decode_instruction(struct elf *elf, struct section *sec,
+unsigned long arch_dest_rela_offset(int addend)
+{
+       return addend + 4;
+}
+
+unsigned long arch_jump_destination(struct instruction *insn)
+{
+       return insn->offset + insn->len + insn->immediate;
+}
+
+#define ADD_OP(op) \
+       if (!(op = calloc(1, sizeof(*op)))) \
+               return -1; \
+       else for (list_add_tail(&op->list, ops_list); op; op = NULL)
+
+int arch_decode_instruction(const struct elf *elf, const struct section *sec,
                            unsigned long offset, unsigned int maxlen,
                            unsigned int *len, enum insn_type *type,
-                           unsigned long *immediate, struct stack_op *op)
+                           unsigned long *immediate,
+                           struct list_head *ops_list)
 {
        struct insn insn;
        int x86_64, sign;
        unsigned char op1, op2, rex = 0, rex_b = 0, rex_r = 0, rex_w = 0,
                      rex_x = 0, modrm = 0, modrm_mod = 0, modrm_rm = 0,
                      modrm_reg = 0, sib = 0;
+       struct stack_op *op = NULL;
+       struct symbol *sym;
 
        x86_64 = is_x86_64(elf);
        if (x86_64 == -1)
@@ -85,7 +104,7 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
        insn_get_length(&insn);
 
        if (!insn_complete(&insn)) {
-               WARN_FUNC("can't decode instruction", sec, offset);
+               WARN("can't decode instruction at %s:0x%lx", sec->name, offset);
                return -1;
        }
 
@@ -123,40 +142,44 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
                if (rex_w && !rex_b && modrm_mod == 3 && modrm_rm == 4) {
 
                        /* add/sub reg, %rsp */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_ADD;
-                       op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
-                       op->dest.type = OP_DEST_REG;
-                       op->dest.reg = CFI_SP;
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_ADD;
+                               op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+                               op->dest.type = OP_DEST_REG;
+                               op->dest.reg = CFI_SP;
+                       }
                }
                break;
 
        case 0x50 ... 0x57:
 
                /* push reg */
-               *type = INSN_STACK;
-               op->src.type = OP_SRC_REG;
-               op->src.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
-               op->dest.type = OP_DEST_PUSH;
+               ADD_OP(op) {
+                       op->src.type = OP_SRC_REG;
+                       op->src.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
+                       op->dest.type = OP_DEST_PUSH;
+               }
 
                break;
 
        case 0x58 ... 0x5f:
 
                /* pop reg */
-               *type = INSN_STACK;
-               op->src.type = OP_SRC_POP;
-               op->dest.type = OP_DEST_REG;
-               op->dest.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
+               ADD_OP(op) {
+                       op->src.type = OP_SRC_POP;
+                       op->dest.type = OP_DEST_REG;
+                       op->dest.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
+               }
 
                break;
 
        case 0x68:
        case 0x6a:
                /* push immediate */
-               *type = INSN_STACK;
-               op->src.type = OP_SRC_CONST;
-               op->dest.type = OP_DEST_PUSH;
+               ADD_OP(op) {
+                       op->src.type = OP_SRC_CONST;
+                       op->dest.type = OP_DEST_PUSH;
+               }
                break;
 
        case 0x70 ... 0x7f:
@@ -170,12 +193,13 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
 
                if (modrm == 0xe4) {
                        /* and imm, %rsp */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_AND;
-                       op->src.reg = CFI_SP;
-                       op->src.offset = insn.immediate.value;
-                       op->dest.type = OP_DEST_REG;
-                       op->dest.reg = CFI_SP;
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_AND;
+                               op->src.reg = CFI_SP;
+                               op->src.offset = insn.immediate.value;
+                               op->dest.type = OP_DEST_REG;
+                               op->dest.reg = CFI_SP;
+                       }
                        break;
                }
 
@@ -187,34 +211,37 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
                        break;
 
                /* add/sub imm, %rsp */
-               *type = INSN_STACK;
-               op->src.type = OP_SRC_ADD;
-               op->src.reg = CFI_SP;
-               op->src.offset = insn.immediate.value * sign;
-               op->dest.type = OP_DEST_REG;
-               op->dest.reg = CFI_SP;
+               ADD_OP(op) {
+                       op->src.type = OP_SRC_ADD;
+                       op->src.reg = CFI_SP;
+                       op->src.offset = insn.immediate.value * sign;
+                       op->dest.type = OP_DEST_REG;
+                       op->dest.reg = CFI_SP;
+               }
                break;
 
        case 0x89:
                if (rex_w && !rex_r && modrm_mod == 3 && modrm_reg == 4) {
 
                        /* mov %rsp, reg */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_REG;
-                       op->src.reg = CFI_SP;
-                       op->dest.type = OP_DEST_REG;
-                       op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b];
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_REG;
+                               op->src.reg = CFI_SP;
+                               op->dest.type = OP_DEST_REG;
+                               op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b];
+                       }
                        break;
                }
 
                if (rex_w && !rex_b && modrm_mod == 3 && modrm_rm == 4) {
 
                        /* mov reg, %rsp */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_REG;
-                       op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
-                       op->dest.type = OP_DEST_REG;
-                       op->dest.reg = CFI_SP;
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_REG;
+                               op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+                               op->dest.type = OP_DEST_REG;
+                               op->dest.reg = CFI_SP;
+                       }
                        break;
                }
 
@@ -224,22 +251,24 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
                    (modrm_mod == 1 || modrm_mod == 2) && modrm_rm == 5) {
 
                        /* mov reg, disp(%rbp) */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_REG;
-                       op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
-                       op->dest.type = OP_DEST_REG_INDIRECT;
-                       op->dest.reg = CFI_BP;
-                       op->dest.offset = insn.displacement.value;
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_REG;
+                               op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+                               op->dest.type = OP_DEST_REG_INDIRECT;
+                               op->dest.reg = CFI_BP;
+                               op->dest.offset = insn.displacement.value;
+                       }
 
                } else if (rex_w && !rex_b && modrm_rm == 4 && sib == 0x24) {
 
                        /* mov reg, disp(%rsp) */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_REG;
-                       op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
-                       op->dest.type = OP_DEST_REG_INDIRECT;
-                       op->dest.reg = CFI_SP;
-                       op->dest.offset = insn.displacement.value;
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_REG;
+                               op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+                               op->dest.type = OP_DEST_REG_INDIRECT;
+                               op->dest.reg = CFI_SP;
+                               op->dest.offset = insn.displacement.value;
+                       }
                }
 
                break;
@@ -248,23 +277,25 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
                if (rex_w && !rex_b && modrm_mod == 1 && modrm_rm == 5) {
 
                        /* mov disp(%rbp), reg */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_REG_INDIRECT;
-                       op->src.reg = CFI_BP;
-                       op->src.offset = insn.displacement.value;
-                       op->dest.type = OP_DEST_REG;
-                       op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_REG_INDIRECT;
+                               op->src.reg = CFI_BP;
+                               op->src.offset = insn.displacement.value;
+                               op->dest.type = OP_DEST_REG;
+                               op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+                       }
 
                } else if (rex_w && !rex_b && sib == 0x24 &&
                           modrm_mod != 3 && modrm_rm == 4) {
 
                        /* mov disp(%rsp), reg */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_REG_INDIRECT;
-                       op->src.reg = CFI_SP;
-                       op->src.offset = insn.displacement.value;
-                       op->dest.type = OP_DEST_REG;
-                       op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_REG_INDIRECT;
+                               op->src.reg = CFI_SP;
+                               op->src.offset = insn.displacement.value;
+                               op->dest.type = OP_DEST_REG;
+                               op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+                       }
                }
 
                break;
@@ -272,28 +303,30 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
        case 0x8d:
                if (sib == 0x24 && rex_w && !rex_b && !rex_x) {
 
-                       *type = INSN_STACK;
-                       if (!insn.displacement.value) {
-                               /* lea (%rsp), reg */
-                               op->src.type = OP_SRC_REG;
-                       } else {
-                               /* lea disp(%rsp), reg */
-                               op->src.type = OP_SRC_ADD;
-                               op->src.offset = insn.displacement.value;
+                       ADD_OP(op) {
+                               if (!insn.displacement.value) {
+                                       /* lea (%rsp), reg */
+                                       op->src.type = OP_SRC_REG;
+                               } else {
+                                       /* lea disp(%rsp), reg */
+                                       op->src.type = OP_SRC_ADD;
+                                       op->src.offset = insn.displacement.value;
+                               }
+                               op->src.reg = CFI_SP;
+                               op->dest.type = OP_DEST_REG;
+                               op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
                        }
-                       op->src.reg = CFI_SP;
-                       op->dest.type = OP_DEST_REG;
-                       op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
 
                } else if (rex == 0x48 && modrm == 0x65) {
 
                        /* lea disp(%rbp), %rsp */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_ADD;
-                       op->src.reg = CFI_BP;
-                       op->src.offset = insn.displacement.value;
-                       op->dest.type = OP_DEST_REG;
-                       op->dest.reg = CFI_SP;
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_ADD;
+                               op->src.reg = CFI_BP;
+                               op->src.offset = insn.displacement.value;
+                               op->dest.type = OP_DEST_REG;
+                               op->dest.reg = CFI_SP;
+                       }
 
                } else if (rex == 0x49 && modrm == 0x62 &&
                           insn.displacement.value == -8) {
@@ -304,12 +337,13 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
                         * Restoring rsp back to its original value after a
                         * stack realignment.
                         */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_ADD;
-                       op->src.reg = CFI_R10;
-                       op->src.offset = -8;
-                       op->dest.type = OP_DEST_REG;
-                       op->dest.reg = CFI_SP;
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_ADD;
+                               op->src.reg = CFI_R10;
+                               op->src.offset = -8;
+                               op->dest.type = OP_DEST_REG;
+                               op->dest.reg = CFI_SP;
+                       }
 
                } else if (rex == 0x49 && modrm == 0x65 &&
                           insn.displacement.value == -16) {
@@ -320,21 +354,23 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
                         * Restoring rsp back to its original value after a
                         * stack realignment.
                         */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_ADD;
-                       op->src.reg = CFI_R13;
-                       op->src.offset = -16;
-                       op->dest.type = OP_DEST_REG;
-                       op->dest.reg = CFI_SP;
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_ADD;
+                               op->src.reg = CFI_R13;
+                               op->src.offset = -16;
+                               op->dest.type = OP_DEST_REG;
+                               op->dest.reg = CFI_SP;
+                       }
                }
 
                break;
 
        case 0x8f:
                /* pop to mem */
-               *type = INSN_STACK;
-               op->src.type = OP_SRC_POP;
-               op->dest.type = OP_DEST_MEM;
+               ADD_OP(op) {
+                       op->src.type = OP_SRC_POP;
+                       op->dest.type = OP_DEST_MEM;
+               }
                break;
 
        case 0x90:
@@ -343,16 +379,18 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
 
        case 0x9c:
                /* pushf */
-               *type = INSN_STACK;
-               op->src.type = OP_SRC_CONST;
-               op->dest.type = OP_DEST_PUSHF;
+               ADD_OP(op) {
+                       op->src.type = OP_SRC_CONST;
+                       op->dest.type = OP_DEST_PUSHF;
+               }
                break;
 
        case 0x9d:
                /* popf */
-               *type = INSN_STACK;
-               op->src.type = OP_SRC_POPF;
-               op->dest.type = OP_DEST_MEM;
+               ADD_OP(op) {
+                       op->src.type = OP_SRC_POPF;
+                       op->dest.type = OP_DEST_MEM;
+               }
                break;
 
        case 0x0f:
@@ -387,16 +425,18 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
                } else if (op2 == 0xa0 || op2 == 0xa8) {
 
                        /* push fs/gs */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_CONST;
-                       op->dest.type = OP_DEST_PUSH;
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_CONST;
+                               op->dest.type = OP_DEST_PUSH;
+                       }
 
                } else if (op2 == 0xa1 || op2 == 0xa9) {
 
                        /* pop fs/gs */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_POP;
-                       op->dest.type = OP_DEST_MEM;
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_POP;
+                               op->dest.type = OP_DEST_MEM;
+                       }
                }
 
                break;
@@ -409,8 +449,8 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
                 * mov bp, sp
                 * pop bp
                 */
-               *type = INSN_STACK;
-               op->dest.type = OP_DEST_LEAVE;
+               ADD_OP(op)
+                       op->dest.type = OP_DEST_LEAVE;
 
                break;
 
@@ -429,14 +469,41 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
                *type = INSN_RETURN;
                break;
 
+       case 0xcf: /* iret */
+               /*
+                * Handle sync_core(), which has an IRET to self.
+                * All other IRET are in STT_NONE entry code.
+                */
+               sym = find_symbol_containing(sec, offset);
+               if (sym && sym->type == STT_FUNC) {
+                       ADD_OP(op) {
+                               /* add $40, %rsp */
+                               op->src.type = OP_SRC_ADD;
+                               op->src.reg = CFI_SP;
+                               op->src.offset = 5*8;
+                               op->dest.type = OP_DEST_REG;
+                               op->dest.reg = CFI_SP;
+                       }
+                       break;
+               }
+
+               /* fallthrough */
+
        case 0xca: /* retf */
        case 0xcb: /* retf */
-       case 0xcf: /* iret */
                *type = INSN_CONTEXT_SWITCH;
                break;
 
        case 0xe8:
                *type = INSN_CALL;
+               /*
+                * For the impact on the stack, a CALL behaves like
+                * a PUSH of an immediate value (the return address).
+                */
+               ADD_OP(op) {
+                       op->src.type = OP_SRC_CONST;
+                       op->dest.type = OP_DEST_PUSH;
+               }
                break;
 
        case 0xfc:
@@ -464,9 +531,10 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
                else if (modrm_reg == 6) {
 
                        /* push from mem */
-                       *type = INSN_STACK;
-                       op->src.type = OP_SRC_CONST;
-                       op->dest.type = OP_DEST_PUSH;
+                       ADD_OP(op) {
+                               op->src.type = OP_SRC_CONST;
+                               op->dest.type = OP_DEST_PUSH;
+                       }
                }
 
                break;
@@ -480,7 +548,7 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
        return 0;
 }
 
-void arch_initial_func_cfi_state(struct cfi_state *state)
+void arch_initial_func_cfi_state(struct cfi_init_state *state)
 {
        int i;