| /* Data structure for communication from the run-time dynamic linker for |
| loaded ELF shared objects. |
| Copyright (C) 1995-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #ifndef _PRIVATE_LINK_H |
| #define _PRIVATE_LINK_H 1 |
| |
| #ifdef _LINK_H |
| # error this should be impossible |
| #endif |
| |
| # ifndef _ISOMAC |
| /* Get most of the contents from the public header, but we define a |
| different `struct link_map' type for private use. The la_objopen |
| prototype uses the type, so we have to declare it separately. */ |
| # define link_map link_map_public |
| # define la_objopen la_objopen_wrongproto |
| # endif |
| |
| #include <elf/link.h> |
| |
| # ifndef _ISOMAC |
| |
| #undef link_map |
| #undef la_objopen |
| |
| struct link_map; |
| extern unsigned int la_objopen (struct link_map *__map, Lmid_t __lmid, |
| uintptr_t *__cookie); |
| |
| #include <stdint.h> |
| #include <stddef.h> |
| #include <linkmap.h> |
| #include <dl-fileid.h> |
| #include <dl-lookupcfg.h> |
| #include <tls.h> |
| #include <libc-lock.h> |
| |
| |
| /* Some internal data structures of the dynamic linker used in the |
| linker map. We only provide forward declarations. */ |
| struct libname_list; |
| struct r_found_version; |
| struct r_search_path_elem; |
| |
| /* Forward declaration. */ |
| struct link_map; |
| |
| /* Structure to describe a single list of scope elements. The lookup |
| functions get passed an array of pointers to such structures. */ |
| struct r_scope_elem |
| { |
| /* Array of maps for the scope. */ |
| struct link_map **r_list; |
| /* Number of entries in the scope. */ |
| unsigned int r_nlist; |
| }; |
| |
| |
| /* Structure to record search path and allocation mechanism. */ |
| struct r_search_path_struct |
| { |
| struct r_search_path_elem **dirs; |
| int malloced; |
| }; |
| |
| |
| /* Structure describing a loaded shared object. The `l_next' and `l_prev' |
| members form a chain of all the shared objects loaded at startup. |
| |
| These data structures exist in space used by the run-time dynamic linker; |
| modifying them may have disastrous results. |
| |
| This data structure might change in future, if necessary. User-level |
| programs must avoid defining objects of this type. */ |
| |
| struct link_map |
| { |
| /* These first few members are part of the protocol with the debugger. |
| This is the same format used in SVR4. */ |
| |
| ElfW(Addr) l_addr; /* Difference between the address in the ELF |
| file and the addresses in memory. */ |
| char *l_name; /* Absolute file name object was found in. */ |
| ElfW(Dyn) *l_ld; /* Dynamic section of the shared object. */ |
| struct link_map *l_next, *l_prev; /* Chain of loaded objects. */ |
| |
| /* All following members are internal to the dynamic linker. |
| They may change without notice. */ |
| |
| /* This is an element which is only ever different from a pointer to |
| the very same copy of this type for ld.so when it is used in more |
| than one namespace. */ |
| struct link_map *l_real; |
| |
| /* Number of the namespace this link map belongs to. */ |
| Lmid_t l_ns; |
| |
| struct libname_list *l_libname; |
| /* Indexed pointers to dynamic section. |
| [0,DT_NUM) are indexed by the processor-independent tags. |
| [DT_NUM,DT_NUM+DT_THISPROCNUM) are indexed by the tag minus DT_LOPROC. |
| [DT_NUM+DT_THISPROCNUM,DT_NUM+DT_THISPROCNUM+DT_VERSIONTAGNUM) are |
| indexed by DT_VERSIONTAGIDX(tagvalue). |
| [DT_NUM+DT_THISPROCNUM+DT_VERSIONTAGNUM, |
| DT_NUM+DT_THISPROCNUM+DT_VERSIONTAGNUM+DT_EXTRANUM) are indexed by |
| DT_EXTRATAGIDX(tagvalue). |
| [DT_NUM+DT_THISPROCNUM+DT_VERSIONTAGNUM+DT_EXTRANUM, |
| DT_NUM+DT_THISPROCNUM+DT_VERSIONTAGNUM+DT_EXTRANUM+DT_VALNUM) are |
| indexed by DT_VALTAGIDX(tagvalue) and |
| [DT_NUM+DT_THISPROCNUM+DT_VERSIONTAGNUM+DT_EXTRANUM+DT_VALNUM, |
| DT_NUM+DT_THISPROCNUM+DT_VERSIONTAGNUM+DT_EXTRANUM+DT_VALNUM+DT_ADDRNUM) |
| are indexed by DT_ADDRTAGIDX(tagvalue), see <elf.h>. */ |
| |
| ElfW(Dyn) *l_info[DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM |
| + DT_EXTRANUM + DT_VALNUM + DT_ADDRNUM]; |
| const ElfW(Phdr) *l_phdr; /* Pointer to program header table in core. */ |
| ElfW(Addr) l_entry; /* Entry point location. */ |
| ElfW(Half) l_phnum; /* Number of program header entries. */ |
| ElfW(Half) l_ldnum; /* Number of dynamic segment entries. */ |
| |
| /* Array of DT_NEEDED dependencies and their dependencies, in |
| dependency order for symbol lookup (with and without |
| duplicates). There is no entry before the dependencies have |
| been loaded. */ |
| struct r_scope_elem l_searchlist; |
| |
| /* We need a special searchlist to process objects marked with |
| DT_SYMBOLIC. */ |
| struct r_scope_elem l_symbolic_searchlist; |
| |
| /* Dependent object that first caused this object to be loaded. */ |
| struct link_map *l_loader; |
| |
| /* Array with version names. */ |
| struct r_found_version *l_versions; |
| unsigned int l_nversions; |
| |
| /* Symbol hash table. */ |
| Elf_Symndx l_nbuckets; |
| Elf32_Word l_gnu_bitmask_idxbits; |
| Elf32_Word l_gnu_shift; |
| const ElfW(Addr) *l_gnu_bitmask; |
| union |
| { |
| const Elf32_Word *l_gnu_buckets; |
| const Elf_Symndx *l_chain; |
| }; |
| union |
| { |
| const Elf32_Word *l_gnu_chain_zero; |
| const Elf_Symndx *l_buckets; |
| }; |
| |
| unsigned int l_direct_opencount; /* Reference count for dlopen/dlclose. */ |
| enum /* Where this object came from. */ |
| { |
| lt_executable, /* The main executable program. */ |
| lt_library, /* Library needed by main executable. */ |
| lt_loaded /* Extra run-time loaded shared object. */ |
| } l_type:2; |
| unsigned int l_relocated:1; /* Nonzero if object's relocations done. */ |
| unsigned int l_init_called:1; /* Nonzero if DT_INIT function called. */ |
| unsigned int l_global:1; /* Nonzero if object in _dl_global_scope. */ |
| unsigned int l_reserved:2; /* Reserved for internal use. */ |
| unsigned int l_phdr_allocated:1; /* Nonzero if the data structure pointed |
| to by `l_phdr' is allocated. */ |
| unsigned int l_inedge:1; /* Used temporarily when sorting deps. */ |
| unsigned int l_faked:1; /* Nonzero if this is a faked descriptor |
| without associated file. */ |
| unsigned int l_need_tls_init:1; /* Nonzero if GL(dl_init_static_tls) |
| should be called on this link map |
| when relocation finishes. */ |
| unsigned int l_auditing:1; /* Nonzero if the DSO is used in auditing. */ |
| unsigned int l_audit_any_plt:1; /* Nonzero if at least one audit module |
| is interested in the PLT interception.*/ |
| unsigned int l_removed:1; /* Nozero if the object cannot be used anymore |
| since it is removed. */ |
| unsigned int l_contiguous:1; /* Nonzero if inter-segment holes are |
| mprotected or if no holes are present at |
| all. */ |
| unsigned int l_symbolic_in_local_scope:1; /* Nonzero if l_local_scope |
| during LD_TRACE_PRELINKING=1 |
| contains any DT_SYMBOLIC |
| libraries. */ |
| unsigned int l_free_initfini:1; /* Nonzero if l_initfini can be |
| freed, ie. not allocated with |
| the dummy malloc in ld.so. */ |
| |
| #include <link_map.h> |
| |
| /* Collected information about own RPATH directories. */ |
| struct r_search_path_struct l_rpath_dirs; |
| |
| /* Collected results of relocation while profiling. */ |
| struct reloc_result |
| { |
| DL_FIXUP_VALUE_TYPE addr; |
| struct link_map *bound; |
| unsigned int boundndx; |
| uint32_t enterexit; |
| unsigned int flags; |
| } *l_reloc_result; |
| |
| /* Pointer to the version information if available. */ |
| ElfW(Versym) *l_versyms; |
| |
| /* String specifying the path where this object was found. */ |
| const char *l_origin; |
| |
| /* Start and finish of memory map for this object. l_map_start |
| need not be the same as l_addr. */ |
| ElfW(Addr) l_map_start, l_map_end; |
| /* End of the executable part of the mapping. */ |
| ElfW(Addr) l_text_end; |
| |
| /* Default array for 'l_scope'. */ |
| struct r_scope_elem *l_scope_mem[4]; |
| /* Size of array allocated for 'l_scope'. */ |
| size_t l_scope_max; |
| /* This is an array defining the lookup scope for this link map. |
| There are initially at most three different scope lists. */ |
| struct r_scope_elem **l_scope; |
| |
| /* A similar array, this time only with the local scope. This is |
| used occasionally. */ |
| struct r_scope_elem *l_local_scope[2]; |
| |
| /* This information is kept to check for sure whether a shared |
| object is the same as one already loaded. */ |
| struct r_file_id l_file_id; |
| |
| /* Google-specific extension, intended to be part of public interface |
| to the debugger. As such, it belongs right after l_prev... except |
| putting it there causes Google libunwind to crash due to its own |
| peeking into glibc internals (see grte_v1_glibc_link_map). */ |
| size_t l_off; /* File offset to Elf_Ehdr. */ |
| |
| /* Collected information about own RUNPATH directories. */ |
| struct r_search_path_struct l_runpath_dirs; |
| |
| /* List of object in order of the init and fini calls. */ |
| struct link_map **l_initfini; |
| |
| /* List of the dependencies introduced through symbol binding. */ |
| struct link_map_reldeps |
| { |
| unsigned int act; |
| struct link_map *list[]; |
| } *l_reldeps; |
| unsigned int l_reldepsmax; |
| |
| /* Nonzero if the DSO is used. */ |
| unsigned int l_used; |
| |
| /* Various flag words. */ |
| ElfW(Word) l_feature_1; |
| ElfW(Word) l_flags_1; |
| ElfW(Word) l_flags; |
| |
| /* Temporarily used in `dl_close'. */ |
| int l_idx; |
| |
| struct link_map_machine l_mach; |
| |
| struct |
| { |
| const ElfW(Sym) *sym; |
| int type_class; |
| struct link_map *value; |
| const ElfW(Sym) *ret; |
| } l_lookup_cache; |
| |
| /* Thread-local storage related info. */ |
| |
| /* Start of the initialization image. */ |
| void *l_tls_initimage; |
| /* Size of the initialization image. */ |
| size_t l_tls_initimage_size; |
| /* Size of the TLS block. */ |
| size_t l_tls_blocksize; |
| /* Alignment requirement of the TLS block. */ |
| size_t l_tls_align; |
| /* Offset of first byte module alignment. */ |
| size_t l_tls_firstbyte_offset; |
| #ifndef NO_TLS_OFFSET |
| # define NO_TLS_OFFSET 0 |
| #endif |
| #ifndef FORCED_DYNAMIC_TLS_OFFSET |
| # if NO_TLS_OFFSET == 0 |
| # define FORCED_DYNAMIC_TLS_OFFSET -1 |
| # elif NO_TLS_OFFSET == -1 |
| # define FORCED_DYNAMIC_TLS_OFFSET -2 |
| # else |
| # error "FORCED_DYNAMIC_TLS_OFFSET is not defined" |
| # endif |
| #endif |
| /* For objects present at startup time: offset in the static TLS block. */ |
| ptrdiff_t l_tls_offset; |
| /* Index of the module in the dtv array. */ |
| size_t l_tls_modid; |
| |
| /* Number of thread_local objects constructed by this DSO. This is |
| atomically accessed and modified and is not always protected by the load |
| lock. See also: CONCURRENCY NOTES in cxa_thread_atexit_impl.c. */ |
| size_t l_tls_dtor_count; |
| |
| /* Information used to change permission after the relocations are |
| done. */ |
| ElfW(Addr) l_relro_addr; |
| size_t l_relro_size; |
| |
| unsigned long long int l_serial; |
| |
| /* Audit information. This array apparent must be the last in the |
| structure. Never add something after it. */ |
| struct auditstate |
| { |
| uintptr_t cookie; |
| unsigned int bindflags; |
| } l_audit[0]; |
| }; |
| |
| |
| #if __ELF_NATIVE_CLASS == 32 |
| # define symbind symbind32 |
| #elif __ELF_NATIVE_CLASS == 64 |
| # define symbind symbind64 |
| #else |
| # error "__ELF_NATIVE_CLASS must be defined" |
| #endif |
| |
| extern int __dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, |
| size_t size, void *data), |
| void *data); |
| hidden_proto (__dl_iterate_phdr) |
| |
| /* We use this macro to refer to ELF macros independent of the native |
| wordsize. `ELFW(R_TYPE)' is used in place of `ELF32_R_TYPE' or |
| `ELF64_R_TYPE'. */ |
| #define ELFW(type) _ElfW (ELF, __ELF_NATIVE_CLASS, type) |
| |
| # endif /* !_ISOMAC */ |
| #endif /* include/link.h */ |
