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Diffstat (limited to 'REORG.TODO/elf/link.h')
| -rw-r--r-- | REORG.TODO/elf/link.h | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/REORG.TODO/elf/link.h b/REORG.TODO/elf/link.h new file mode 100644 index 0000000000..0e223ce9f0 --- /dev/null +++ b/REORG.TODO/elf/link.h @@ -0,0 +1,194 @@ +/* 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 _LINK_H +#define _LINK_H 1 + +#include <features.h> +#include <elf.h> +#include <dlfcn.h> +#include <sys/types.h> + +/* We use this macro to refer to ELF types independent of the native wordsize. + `ElfW(TYPE)' is used in place of `Elf32_TYPE' or `Elf64_TYPE'. */ +#define ElfW(type) _ElfW (Elf, __ELF_NATIVE_CLASS, type) +#define _ElfW(e,w,t) _ElfW_1 (e, w, _##t) +#define _ElfW_1(e,w,t) e##w##t + +#include <bits/elfclass.h> /* Defines __ELF_NATIVE_CLASS. */ +#include <bits/link.h> + +/* Rendezvous structure used by the run-time dynamic linker to communicate + details of shared object loading to the debugger. If the executable's + dynamic section has a DT_DEBUG element, the run-time linker sets that + element's value to the address where this structure can be found. */ + +struct r_debug + { + int r_version; /* Version number for this protocol. */ + + struct link_map *r_map; /* Head of the chain of loaded objects. */ + + /* This is the address of a function internal to the run-time linker, + that will always be called when the linker begins to map in a + library or unmap it, and again when the mapping change is complete. + The debugger can set a breakpoint at this address if it wants to + notice shared object mapping changes. */ + ElfW(Addr) r_brk; + enum + { + /* This state value describes the mapping change taking place when + the `r_brk' address is called. */ + RT_CONSISTENT, /* Mapping change is complete. */ + RT_ADD, /* Beginning to add a new object. */ + RT_DELETE /* Beginning to remove an object mapping. */ + } r_state; + + ElfW(Addr) r_ldbase; /* Base address the linker is loaded at. */ + }; + +/* This is the instance of that structure used by the dynamic linker. */ +extern struct r_debug _r_debug; + +/* This symbol refers to the "dynamic structure" in the `.dynamic' section + of whatever module refers to `_DYNAMIC'. So, to find its own + `struct r_debug', a program could do: + for (dyn = _DYNAMIC; dyn->d_tag != DT_NULL; ++dyn) + if (dyn->d_tag == DT_DEBUG) + r_debug = (struct r_debug *) dyn->d_un.d_ptr; + */ +extern ElfW(Dyn) _DYNAMIC[]; + +/* 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. */ + +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. */ + }; + +#ifdef __USE_GNU + +/* Version numbers for la_version handshake interface. */ +#define LAV_CURRENT 1 + +/* Activity types signaled through la_activity. */ +enum + { + LA_ACT_CONSISTENT, /* Link map consistent again. */ + LA_ACT_ADD, /* New object will be added. */ + LA_ACT_DELETE /* Objects will be removed. */ + }; + +/* Values representing origin of name for dynamic loading. */ +enum + { + LA_SER_ORIG = 0x01, /* Original name. */ + LA_SER_LIBPATH = 0x02, /* Directory from LD_LIBRARY_PATH. */ + LA_SER_RUNPATH = 0x04, /* Directory from RPATH/RUNPATH. */ + LA_SER_CONFIG = 0x08, /* Found through ldconfig. */ + LA_SER_DEFAULT = 0x40, /* Default directory. */ + LA_SER_SECURE = 0x80 /* Unused. */ + }; + +/* Values for la_objopen return value. */ +enum + { + LA_FLG_BINDTO = 0x01, /* Audit symbols bound to this object. */ + LA_FLG_BINDFROM = 0x02 /* Audit symbols bound from this object. */ + }; + +/* Values for la_symbind flags parameter. */ +enum + { + LA_SYMB_NOPLTENTER = 0x01, /* la_pltenter will not be called. */ + LA_SYMB_NOPLTEXIT = 0x02, /* la_pltexit will not be called. */ + LA_SYMB_STRUCTCALL = 0x04, /* Return value is a structure. */ + LA_SYMB_DLSYM = 0x08, /* Binding due to dlsym call. */ + LA_SYMB_ALTVALUE = 0x10 /* Value has been changed by a previous + la_symbind call. */ + }; + +struct dl_phdr_info + { + ElfW(Addr) dlpi_addr; + const char *dlpi_name; + const ElfW(Phdr) *dlpi_phdr; + ElfW(Half) dlpi_phnum; + + /* Note: Following members were introduced after the first + version of this structure was available. Check the SIZE + argument passed to the dl_iterate_phdr callback to determine + whether or not each later member is available. */ + + /* Incremented when a new object may have been added. */ + __extension__ unsigned long long int dlpi_adds; + /* Incremented when an object may have been removed. */ + __extension__ unsigned long long int dlpi_subs; + + /* If there is a PT_TLS segment, its module ID as used in + TLS relocations, else zero. */ + size_t dlpi_tls_modid; + + /* The address of the calling thread's instance of this module's + PT_TLS segment, if it has one and it has been allocated + in the calling thread, otherwise a null pointer. */ + void *dlpi_tls_data; + }; + +__BEGIN_DECLS + +extern int dl_iterate_phdr (int (*__callback) (struct dl_phdr_info *, + size_t, void *), + void *__data); + + +/* Prototypes for the ld.so auditing interfaces. These are not + defined anywhere in ld.so but instead have to be provided by the + auditing DSO. */ +extern unsigned int la_version (unsigned int __version); +extern void la_activity (uintptr_t *__cookie, unsigned int __flag); +extern char *la_objsearch (const char *__name, uintptr_t *__cookie, + unsigned int __flag); +extern unsigned int la_objopen (struct link_map *__map, Lmid_t __lmid, + uintptr_t *__cookie); +extern void la_preinit (uintptr_t *__cookie); +extern uintptr_t la_symbind32 (Elf32_Sym *__sym, unsigned int __ndx, + uintptr_t *__refcook, uintptr_t *__defcook, + unsigned int *__flags, const char *__symname); +extern uintptr_t la_symbind64 (Elf64_Sym *__sym, unsigned int __ndx, + uintptr_t *__refcook, uintptr_t *__defcook, + unsigned int *__flags, const char *__symname); +extern unsigned int la_objclose (uintptr_t *__cookie); + +__END_DECLS + +#endif + +#endif /* link.h */ |