diff options
Diffstat (limited to 'tools/objtool/arch/x86/decode.c')
| -rw-r--r-- | tools/objtool/arch/x86/decode.c | 167 |
1 files changed, 142 insertions, 25 deletions
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index fe1362c34564..f4af82508228 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -16,14 +16,22 @@ #include <asm/orc_types.h> #include <objtool/check.h> +#include <objtool/disas.h> #include <objtool/elf.h> #include <objtool/arch.h> #include <objtool/warn.h> -#include <objtool/endianness.h> #include <objtool/builtin.h> #include <arch/elf.h> -int arch_ftrace_match(char *name) +const char *arch_reg_name[CFI_NUM_REGS] = { + "rax", "rcx", "rdx", "rbx", + "rsp", "rbp", "rsi", "rdi", + "r8", "r9", "r10", "r11", + "r12", "r13", "r14", "r15", + "ra" +}; + +int arch_ftrace_match(const char *name) { return !strcmp(name, "__fentry__"); } @@ -36,7 +44,7 @@ static int is_x86_64(const struct elf *elf) case EM_386: return 0; default: - WARN("unexpected ELF machine type %d", elf->ehdr.e_machine); + ERROR("unexpected ELF machine type %d", elf->ehdr.e_machine); return -1; } } @@ -68,9 +76,65 @@ bool arch_callee_saved_reg(unsigned char reg) } } -unsigned long arch_dest_reloc_offset(int addend) +/* Undo the effects of __pa_symbol() if necessary */ +static unsigned long phys_to_virt(unsigned long pa) { - return addend + 4; + s64 va = pa; + + if (va > 0) + va &= ~(0x80000000); + + return va; +} + +s64 arch_insn_adjusted_addend(struct instruction *insn, struct reloc *reloc) +{ + s64 addend = reloc_addend(reloc); + + if (arch_pc_relative_reloc(reloc)) + addend += insn->offset + insn->len - reloc_offset(reloc); + + return phys_to_virt(addend); +} + +static void scan_for_insn(struct section *sec, unsigned long offset, + unsigned long *insn_off, unsigned int *insn_len) +{ + unsigned long o = 0; + struct insn insn; + + while (1) { + + insn_decode(&insn, sec->data->d_buf + o, sec_size(sec) - o, + INSN_MODE_64); + + if (o + insn.length > offset) { + *insn_off = o; + *insn_len = insn.length; + return; + } + + o += insn.length; + } +} + +u64 arch_adjusted_addend(struct reloc *reloc) +{ + unsigned int type = reloc_type(reloc); + s64 addend = reloc_addend(reloc); + unsigned long insn_off; + unsigned int insn_len; + + if (type == R_X86_64_PLT32) + return addend + 4; + + if (type != R_X86_64_PC32 || !is_text_sec(reloc->sec->base)) + return addend; + + scan_for_insn(reloc->sec->base, reloc_offset(reloc), + &insn_off, &insn_len); + + return addend + insn_off + insn_len - reloc_offset(reloc); } unsigned long arch_jump_destination(struct instruction *insn) @@ -173,7 +237,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec ret = insn_decode(&ins, sec->data->d_buf + offset, maxlen, x86_64 ? INSN_MODE_64 : INSN_MODE_32); if (ret < 0) { - WARN("can't decode instruction at %s:0x%lx", sec->name, offset); + ERROR("can't decode instruction at %s:0x%lx", sec->name, offset); return -1; } @@ -321,7 +385,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec break; default: - /* WARN ? */ + /* ERROR ? */ break; } @@ -494,6 +558,12 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec break; case 0x90: + if (rex_b) /* XCHG %r8, %rax */ + break; + + if (prefix == 0xf3) /* REP NOP := PAUSE */ + break; + insn->type = INSN_NOP; break; @@ -522,7 +592,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec case INAT_PFX_REPNE: if (modrm == 0xca) /* eretu/erets */ - insn->type = INSN_CONTEXT_SWITCH; + insn->type = INSN_SYSRET; break; default: if (modrm == 0xca) @@ -535,21 +605,26 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec insn->type = INSN_JUMP_CONDITIONAL; - } else if (op2 == 0x05 || op2 == 0x07 || op2 == 0x34 || - op2 == 0x35) { + } else if (op2 == 0x05 || op2 == 0x34) { + + /* syscall, sysenter */ + insn->type = INSN_SYSCALL; - /* sysenter, sysret */ - insn->type = INSN_CONTEXT_SWITCH; + } else if (op2 == 0x07 || op2 == 0x35) { + + /* sysret, sysexit */ + insn->type = INSN_SYSRET; } else if (op2 == 0x0b || op2 == 0xb9) { - /* ud2 */ + /* ud2, ud1 */ insn->type = INSN_BUG; - } else if (op2 == 0x0d || op2 == 0x1f) { + } else if (op2 == 0x1f) { - /* nopl/nopw */ - insn->type = INSN_NOP; + /* 0f 1f /0 := NOPL */ + if (modrm_reg == 0) + insn->type = INSN_NOP; } else if (op2 == 0x1e) { @@ -561,8 +636,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec if (ins.prefixes.nbytes == 1 && ins.prefixes.bytes[0] == 0xf2) { /* ENQCMD cannot be used in the kernel. */ - WARN("ENQCMD instruction at %s:%lx", sec->name, - offset); + WARN("ENQCMD instruction at %s:%lx", sec->name, offset); } } else if (op2 == 0xa0 || op2 == 0xa8) { @@ -646,7 +720,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec if (disp->sym->type == STT_SECTION) func = find_symbol_by_offset(disp->sym->sec, reloc_addend(disp)); if (!func) { - WARN("no func for pv_ops[]"); + ERROR("no func for pv_ops[]"); return -1; } @@ -677,7 +751,11 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec case 0xca: /* retf */ case 0xcb: /* retf */ - insn->type = INSN_CONTEXT_SWITCH; + insn->type = INSN_SYSRET; + break; + + case 0xd6: /* udb */ + insn->type = INSN_BUG; break; case 0xe0: /* loopne */ @@ -722,7 +800,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec } else if (modrm_reg == 5) { /* jmpf */ - insn->type = INSN_CONTEXT_SWITCH; + insn->type = INSN_SYSRET; } else if (modrm_reg == 6) { @@ -776,7 +854,7 @@ const char *arch_nop_insn(int len) }; if (len < 1 || len > 5) { - WARN("invalid NOP size: %d\n", len); + ERROR("invalid NOP size: %d\n", len); return NULL; } @@ -796,7 +874,7 @@ const char *arch_ret_insn(int len) }; if (len < 1 || len > 5) { - WARN("invalid RET size: %d\n", len); + ERROR("invalid RET size: %d\n", len); return NULL; } @@ -839,16 +917,55 @@ int arch_decode_hint_reg(u8 sp_reg, int *base) bool arch_is_retpoline(struct symbol *sym) { - return !strncmp(sym->name, "__x86_indirect_", 15); + return !strncmp(sym->name, "__x86_indirect_", 15) || + !strncmp(sym->name, "__pi___x86_indirect_", 20); } bool arch_is_rethunk(struct symbol *sym) { - return !strcmp(sym->name, "__x86_return_thunk"); + return !strcmp(sym->name, "__x86_return_thunk") || + !strcmp(sym->name, "__pi___x86_return_thunk"); } bool arch_is_embedded_insn(struct symbol *sym) { return !strcmp(sym->name, "retbleed_return_thunk") || + !strcmp(sym->name, "srso_alias_safe_ret") || !strcmp(sym->name, "srso_safe_ret"); } + +unsigned int arch_reloc_size(struct reloc *reloc) +{ + switch (reloc_type(reloc)) { + case R_X86_64_32: + case R_X86_64_32S: + case R_X86_64_PC32: + case R_X86_64_PLT32: + return 4; + default: + return 8; + } +} + +bool arch_absolute_reloc(struct elf *elf, struct reloc *reloc) +{ + switch (reloc_type(reloc)) { + case R_X86_64_32: + case R_X86_64_32S: + case R_X86_64_64: + return true; + default: + return false; + } +} + +#ifdef DISAS + +int arch_disas_info_init(struct disassemble_info *dinfo) +{ + return disas_info_init(dinfo, bfd_arch_i386, + bfd_mach_i386_i386, bfd_mach_x86_64, + "att"); +} + +#endif /* DISAS */ |
