diff --git a/linker/linker.h b/linker/linker.h
index 61ef259..aa6d00b 100644
--- a/linker/linker.h
+++ b/linker/linker.h
@@ -42,25 +42,11 @@
 #include "linked_list.h"
 #include "linker_common_types.h"
 #include "linker_logger.h"
+#include "linker_soinfo.h"
 
 #include <string>
 #include <vector>
 
-#define DL_ERR(fmt, x...) \
-    do { \
-      __libc_format_buffer(linker_get_error_buffer(), linker_get_error_buffer_size(), fmt, ##x); \
-      /* If LD_DEBUG is set high enough, log every dlerror(3) message. */ \
-      LD_LOG(kLogErrors, "%s\n", linker_get_error_buffer()); \
-    } while (false)
-
-#define DL_WARN(fmt, x...) \
-    do { \
-      __libc_format_log(ANDROID_LOG_WARN, "linker", fmt, ##x); \
-      __libc_format_fd(2, "WARNING: linker: "); \
-      __libc_format_fd(2, fmt, ##x); \
-      __libc_format_fd(2, "\n"); \
-    } while (false)
-
 #if defined(__LP64__)
 #define ELFW(what) ELF64_ ## what
 #else
@@ -81,61 +67,8 @@
 #define ELF64_R_TYPE(info)  (((info) >> 56) & 0xff)
 #endif
 
-#define FLAG_LINKED           0x00000001
-#define FLAG_EXE              0x00000004 // The main executable
-#define FLAG_LINKER           0x00000010 // The linker itself
-#define FLAG_GNU_HASH         0x00000040 // uses gnu hash
-#define FLAG_MAPPED_BY_CALLER 0x00000080 // the map is reserved by the caller
-                                         // and should not be unmapped
-#define FLAG_NEW_SOINFO       0x40000000 // new soinfo format
-
 #define SUPPORTED_DT_FLAGS_1 (DF_1_NOW | DF_1_GLOBAL | DF_1_NODELETE)
 
-#define SOINFO_VERSION 3
-
-#if defined(__work_around_b_24465209__)
-#define SOINFO_NAME_LEN 128
-#endif
-
-typedef void (*linker_dtor_function_t)();
-typedef void (*linker_ctor_function_t)(int, char**, char**);
-
-// Android uses RELA for aarch64 and x86_64. mips64 still uses REL.
-#if defined(__aarch64__) || defined(__x86_64__)
-#define USE_RELA 1
-#endif
-
-class SymbolName {
- public:
-  explicit SymbolName(const char* name)
-      : name_(name), has_elf_hash_(false), has_gnu_hash_(false),
-        elf_hash_(0), gnu_hash_(0) { }
-
-  const char* get_name() {
-    return name_;
-  }
-
-  uint32_t elf_hash();
-  uint32_t gnu_hash();
-
- private:
-  const char* name_;
-  bool has_elf_hash_;
-  bool has_gnu_hash_;
-  uint32_t elf_hash_;
-  uint32_t gnu_hash_;
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(SymbolName);
-};
-
-struct version_info {
-  constexpr version_info() : elf_hash(0), name(nullptr), target_si(nullptr) {}
-
-  uint32_t elf_hash;
-  const char* name;
-  const soinfo* target_si;
-};
-
 // Class used construct version dependency graph.
 class VersionTracker {
  public:
@@ -154,262 +87,6 @@
   DISALLOW_COPY_AND_ASSIGN(VersionTracker);
 };
 
-struct soinfo {
- public:
-#if defined(__work_around_b_24465209__)
- private:
-  char old_name_[SOINFO_NAME_LEN];
-#endif
- public:
-  const ElfW(Phdr)* phdr;
-  size_t phnum;
-#if defined(__work_around_b_24465209__)
-  ElfW(Addr) unused0; // DO NOT USE, maintained for compatibility.
-#endif
-  ElfW(Addr) base;
-  size_t size;
-
-#if defined(__work_around_b_24465209__)
-  uint32_t unused1;  // DO NOT USE, maintained for compatibility.
-#endif
-
-  ElfW(Dyn)* dynamic;
-
-#if defined(__work_around_b_24465209__)
-  uint32_t unused2; // DO NOT USE, maintained for compatibility
-  uint32_t unused3; // DO NOT USE, maintained for compatibility
-#endif
-
-  soinfo* next;
- private:
-  uint32_t flags_;
-
-  const char* strtab_;
-  ElfW(Sym)* symtab_;
-
-  size_t nbucket_;
-  size_t nchain_;
-  uint32_t* bucket_;
-  uint32_t* chain_;
-
-#if defined(__mips__) || !defined(__LP64__)
-  // This is only used by mips and mips64, but needs to be here for
-  // all 32-bit architectures to preserve binary compatibility.
-  ElfW(Addr)** plt_got_;
-#endif
-
-#if defined(USE_RELA)
-  ElfW(Rela)* plt_rela_;
-  size_t plt_rela_count_;
-
-  ElfW(Rela)* rela_;
-  size_t rela_count_;
-#else
-  ElfW(Rel)* plt_rel_;
-  size_t plt_rel_count_;
-
-  ElfW(Rel)* rel_;
-  size_t rel_count_;
-#endif
-
-  linker_ctor_function_t* preinit_array_;
-  size_t preinit_array_count_;
-
-  linker_ctor_function_t* init_array_;
-  size_t init_array_count_;
-  linker_dtor_function_t* fini_array_;
-  size_t fini_array_count_;
-
-  linker_ctor_function_t init_func_;
-  linker_dtor_function_t fini_func_;
-
-#if defined(__arm__)
- public:
-  // ARM EABI section used for stack unwinding.
-  uint32_t* ARM_exidx;
-  size_t ARM_exidx_count;
- private:
-#elif defined(__mips__)
-  uint32_t mips_symtabno_;
-  uint32_t mips_local_gotno_;
-  uint32_t mips_gotsym_;
-  bool mips_relocate_got(const VersionTracker& version_tracker,
-                         const soinfo_list_t& global_group,
-                         const soinfo_list_t& local_group);
-#if !defined(__LP64__)
-  bool mips_check_and_adjust_fp_modes();
-#endif
-#endif
-  size_t ref_count_;
- public:
-  link_map link_map_head;
-
-  bool constructors_called;
-
-  // When you read a virtual address from the ELF file, add this
-  // value to get the corresponding address in the process' address space.
-  ElfW(Addr) load_bias;
-
-#if !defined(__LP64__)
-  bool has_text_relocations;
-#endif
-  bool has_DT_SYMBOLIC;
-
- public:
-  soinfo(android_namespace_t* ns, const char* name, const struct stat* file_stat,
-         off64_t file_offset, int rtld_flags);
-  ~soinfo();
-
-  void call_constructors();
-  void call_destructors();
-  void call_pre_init_constructors();
-  bool prelink_image();
-  bool link_image(const soinfo_list_t& global_group, const soinfo_list_t& local_group,
-                  const android_dlextinfo* extinfo);
-  bool protect_relro();
-
-  void add_child(soinfo* child);
-  void remove_all_links();
-
-  ino_t get_st_ino() const;
-  dev_t get_st_dev() const;
-  off64_t get_file_offset() const;
-
-  uint32_t get_rtld_flags() const;
-  uint32_t get_dt_flags_1() const;
-  void set_dt_flags_1(uint32_t dt_flags_1);
-
-  soinfo_list_t& get_children();
-  const soinfo_list_t& get_children() const;
-
-  soinfo_list_t& get_parents();
-
-  bool find_symbol_by_name(SymbolName& symbol_name,
-                           const version_info* vi,
-                           const ElfW(Sym)** symbol) const;
-
-  ElfW(Sym)* find_symbol_by_address(const void* addr);
-  ElfW(Addr) resolve_symbol_address(const ElfW(Sym)* s) const;
-
-  const char* get_string(ElfW(Word) index) const;
-  bool can_unload() const;
-  bool is_gnu_hash() const;
-
-  bool inline has_min_version(uint32_t min_version __unused) const {
-#if defined(__work_around_b_24465209__)
-    return (flags_ & FLAG_NEW_SOINFO) != 0 && version_ >= min_version;
-#else
-    return true;
-#endif
-  }
-
-  bool is_linked() const;
-  bool is_linker() const;
-  bool is_main_executable() const;
-
-  void set_linked();
-  void set_linker_flag();
-  void set_main_executable();
-  void set_nodelete();
-
-  void increment_ref_count();
-  size_t decrement_ref_count();
-
-  soinfo* get_local_group_root() const;
-
-  void set_soname(const char* soname);
-  const char* get_soname() const;
-  const char* get_realpath() const;
-  const ElfW(Versym)* get_versym(size_t n) const;
-  ElfW(Addr) get_verneed_ptr() const;
-  size_t get_verneed_cnt() const;
-  ElfW(Addr) get_verdef_ptr() const;
-  size_t get_verdef_cnt() const;
-
-  bool find_verdef_version_index(const version_info* vi, ElfW(Versym)* versym) const;
-
-  uint32_t get_target_sdk_version() const;
-
-  void set_dt_runpath(const char *);
-  const std::vector<std::string>& get_dt_runpath() const;
-  android_namespace_t* get_primary_namespace();
-  void add_secondary_namespace(android_namespace_t* secondary_ns);
-
-  void set_mapped_by_caller(bool reserved_map);
-  bool is_mapped_by_caller() const;
-
-  uintptr_t get_handle() const;
-  void generate_handle();
-  void* to_handle();
-
- private:
-  bool elf_lookup(SymbolName& symbol_name, const version_info* vi, uint32_t* symbol_index) const;
-  ElfW(Sym)* elf_addr_lookup(const void* addr);
-  bool gnu_lookup(SymbolName& symbol_name, const version_info* vi, uint32_t* symbol_index) const;
-  ElfW(Sym)* gnu_addr_lookup(const void* addr);
-
-  bool lookup_version_info(const VersionTracker& version_tracker, ElfW(Word) sym,
-                           const char* sym_name, const version_info** vi);
-
-  template<typename ElfRelIteratorT>
-  bool relocate(const VersionTracker& version_tracker, ElfRelIteratorT&& rel_iterator,
-                const soinfo_list_t& global_group, const soinfo_list_t& local_group);
-
- private:
-  // This part of the structure is only available
-  // when FLAG_NEW_SOINFO is set in this->flags.
-  uint32_t version_;
-
-  // version >= 0
-  dev_t st_dev_;
-  ino_t st_ino_;
-
-  // dependency graph
-  soinfo_list_t children_;
-  soinfo_list_t parents_;
-
-  // version >= 1
-  off64_t file_offset_;
-  uint32_t rtld_flags_;
-  uint32_t dt_flags_1_;
-  size_t strtab_size_;
-
-  // version >= 2
-
-  size_t gnu_nbucket_;
-  uint32_t* gnu_bucket_;
-  uint32_t* gnu_chain_;
-  uint32_t gnu_maskwords_;
-  uint32_t gnu_shift2_;
-  ElfW(Addr)* gnu_bloom_filter_;
-
-  soinfo* local_group_root_;
-
-  uint8_t* android_relocs_;
-  size_t android_relocs_size_;
-
-  const char* soname_;
-  std::string realpath_;
-
-  const ElfW(Versym)* versym_;
-
-  ElfW(Addr) verdef_ptr_;
-  size_t verdef_cnt_;
-
-  ElfW(Addr) verneed_ptr_;
-  size_t verneed_cnt_;
-
-  uint32_t target_sdk_version_;
-
-  // version >= 3
-  std::vector<std::string> dt_runpath_;
-  android_namespace_t* primary_namespace_;
-  android_namespace_list_t secondary_namespaces_;
-  uintptr_t handle_;
-
-  friend soinfo* get_libdl_info();
-};
-
 bool soinfo_do_lookup(soinfo* si_from, const char* name, const version_info* vi,
                       soinfo** si_found_in, const soinfo_list_t& global_group,
                       const soinfo_list_t& local_group, const ElfW(Sym)** symbol);
@@ -438,9 +115,6 @@
 
 int do_dladdr(const void* addr, Dl_info* info);
 
-char* linker_get_error_buffer();
-size_t linker_get_error_buffer_size();
-
 void set_application_target_sdk_version(uint32_t target);
 uint32_t get_application_target_sdk_version();