--- /dev/null
+/* 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 _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 */
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