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Diffstat (limited to 'REORG.TODO/include/link.h')
| -rw-r--r-- | REORG.TODO/include/link.h | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/REORG.TODO/include/link.h b/REORG.TODO/include/link.h new file mode 100644 index 0000000000..eeb5f4d53b --- /dev/null +++ b/REORG.TODO/include/link.h @@ -0,0 +1,351 @@ +/* Data structure for communication from the run-time dynamic linker for + loaded ELF shared objects. + Copyright (C) 1995-2017 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_soname_added:1; /* Nonzero if the SONAME is for sure in + the l_libname list. */ + 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. */ + + /* 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; + + /* 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); + +/* 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 */ |