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- /* Run-time dynamic linker data structures for loaded ELF shared objects.
- Copyright (C) 1995-2019 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 _LDSODEFS_H
- #define _LDSODEFS_H 1
- #include <features.h>
- #include <stdbool.h>
- #define __need_size_t
- #define __need_NULL
- #include <stddef.h>
- #include <string.h>
- #include <stdint.h>
- #include <elf.h>
- #include <dlfcn.h>
- #include <fpu_control.h>
- #include <sys/mman.h>
- #include <link.h>
- #include <dl-lookupcfg.h>
- #include <dl-sysdep.h>
- #include <libc-lock.h>
- #include <hp-timing.h>
- #include <tls.h>
- __BEGIN_DECLS
- #define VERSYMIDX(sym) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (sym))
- #define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
- + DT_EXTRANUM + DT_VALTAGIDX (tag))
- #define ADDRIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
- + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag))
- /* 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)
- /* All references to the value of l_info[DT_PLTGOT],
- l_info[DT_STRTAB], l_info[DT_SYMTAB], l_info[DT_RELA],
- l_info[DT_REL], l_info[DT_JMPREL], and l_info[VERSYMIDX (DT_VERSYM)]
- have to be accessed via the D_PTR macro. The macro is needed since for
- most architectures the entry is already relocated - but for some not
- and we need to relocate at access time. */
- #ifdef DL_RO_DYN_SECTION
- # define D_PTR(map, i) ((map)->i->d_un.d_ptr + (map)->l_addr)
- #else
- # define D_PTR(map, i) (map)->i->d_un.d_ptr
- #endif
- /* Result of the lookup functions and how to retrieve the base address. */
- typedef struct link_map *lookup_t;
- #define LOOKUP_VALUE(map) map
- #define LOOKUP_VALUE_ADDRESS(map, set) ((set) || (map) ? (map)->l_addr : 0)
- /* Calculate the address of symbol REF using the base address from map MAP,
- if non-NULL. Don't check for NULL map if MAP_SET is TRUE. */
- #define SYMBOL_ADDRESS(map, ref, map_set) \
- ((ref) == NULL ? 0 \
- : (__glibc_unlikely ((ref)->st_shndx == SHN_ABS) ? 0 \
- : LOOKUP_VALUE_ADDRESS (map, map_set)) + (ref)->st_value)
- /* On some architectures a pointer to a function is not just a pointer
- to the actual code of the function but rather an architecture
- specific descriptor. */
- #ifndef ELF_FUNCTION_PTR_IS_SPECIAL
- # define DL_SYMBOL_ADDRESS(map, ref) \
- (void *) SYMBOL_ADDRESS (map, ref, false)
- # define DL_LOOKUP_ADDRESS(addr) ((ElfW(Addr)) (addr))
- # define DL_CALL_DT_INIT(map, start, argc, argv, env) \
- ((init_t) (start)) (argc, argv, env)
- # define DL_CALL_DT_FINI(map, start) ((fini_t) (start)) ()
- #endif
- /* On some architectures dladdr can't use st_size of all symbols this way. */
- #define DL_ADDR_SYM_MATCH(L, SYM, MATCHSYM, ADDR) \
- ((ADDR) >= (L)->l_addr + (SYM)->st_value \
- && ((((SYM)->st_shndx == SHN_UNDEF || (SYM)->st_size == 0) \
- && (ADDR) == (L)->l_addr + (SYM)->st_value) \
- || (ADDR) < (L)->l_addr + (SYM)->st_value + (SYM)->st_size) \
- && ((MATCHSYM) == NULL || (MATCHSYM)->st_value < (SYM)->st_value))
- /* According to the ELF gABI no STV_HIDDEN or STV_INTERNAL symbols are
- expected to be present in dynamic symbol tables as they should have
- been either removed or converted to STB_LOCAL binding by the static
- linker. However some GNU binutils versions produce such symbols in
- some cases. To prevent such symbols present in a buggy binary from
- preempting global symbols we filter them out with this predicate. */
- static __always_inline bool
- dl_symbol_visibility_binds_local_p (const ElfW(Sym) *sym)
- {
- return (ELFW(ST_VISIBILITY) (sym->st_other) == STV_HIDDEN
- || ELFW(ST_VISIBILITY) (sym->st_other) == STV_INTERNAL);
- }
- /* Unmap a loaded object, called by _dl_close (). */
- #ifndef DL_UNMAP_IS_SPECIAL
- # define DL_UNMAP(map) _dl_unmap_segments (map)
- #endif
- /* By default we do not need special support to initialize DSOs loaded
- by statically linked binaries. */
- #ifndef DL_STATIC_INIT
- # define DL_STATIC_INIT(map)
- #endif
- /* Reloc type classes as returned by elf_machine_type_class().
- ELF_RTYPE_CLASS_PLT means this reloc should not be satisfied by
- some PLT symbol, ELF_RTYPE_CLASS_COPY means this reloc should not be
- satisfied by any symbol in the executable. Some architectures do
- not support copy relocations. In this case we define the macro to
- zero so that the code for handling them gets automatically optimized
- out. ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA means address of protected
- data defined in the shared library may be external, i.e., due to copy
- relocation. */
- #define ELF_RTYPE_CLASS_PLT 1
- #ifndef DL_NO_COPY_RELOCS
- # define ELF_RTYPE_CLASS_COPY 2
- #else
- # define ELF_RTYPE_CLASS_COPY 0
- #endif
- /* If DL_EXTERN_PROTECTED_DATA is defined, address of protected data
- defined in the shared library may be external, i.e., due to copy
- relocation. */
- #ifdef DL_EXTERN_PROTECTED_DATA
- # define ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA 4
- #else
- # define ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA 0
- #endif
- /* ELF uses the PF_x macros to specify the segment permissions, mmap
- uses PROT_xxx. In most cases the three macros have the values 1, 2,
- and 3 but not in a matching order. The following macros allows
- converting from the PF_x values to PROT_xxx values. */
- #define PF_TO_PROT \
- ((PROT_READ << (PF_R * 4)) \
- | (PROT_WRITE << (PF_W * 4)) \
- | (PROT_EXEC << (PF_X * 4)) \
- | ((PROT_READ | PROT_WRITE) << ((PF_R | PF_W) * 4)) \
- | ((PROT_READ | PROT_EXEC) << ((PF_R | PF_X) * 4)) \
- | ((PROT_WRITE | PROT_EXEC) << (PF_W | PF_X) * 4) \
- | ((PROT_READ | PROT_WRITE | PROT_EXEC) << ((PF_R | PF_W | PF_X) * 4)))
- /* The filename itself, or the main program name, if available. */
- #define DSO_FILENAME(name) ((name)[0] ? (name) \
- : (rtld_progname ?: "<main program>"))
- #define RTLD_PROGNAME (rtld_progname ?: "<program name unknown>")
- /* For the version handling we need an array with only names and their
- hash values. */
- struct r_found_version
- {
- const char *name;
- ElfW(Word) hash;
- int hidden;
- const char *filename;
- };
- /* We want to cache information about the searches for shared objects. */
- enum r_dir_status { unknown, nonexisting, existing };
- struct r_search_path_elem
- {
- /* This link is only used in the `all_dirs' member of `r_search_path'. */
- struct r_search_path_elem *next;
- /* Strings saying where the definition came from. */
- const char *what;
- const char *where;
- /* Basename for this search path element. The string must end with
- a slash character. */
- const char *dirname;
- size_t dirnamelen;
- enum r_dir_status status[0];
- };
- struct r_strlenpair
- {
- const char *str;
- size_t len;
- };
- /* A data structure for a simple single linked list of strings. */
- struct libname_list
- {
- const char *name; /* Name requested (before search). */
- struct libname_list *next; /* Link to next name for this object. */
- int dont_free; /* Flag whether this element should be freed
- if the object is not entirely unloaded. */
- };
- /* Bit masks for the objects which valid callers can come from to
- functions with restricted interface. */
- enum allowmask
- {
- allow_libc = 1,
- allow_libdl = 2,
- allow_libpthread = 4,
- allow_ldso = 8
- };
- struct audit_ifaces
- {
- void (*activity) (uintptr_t *, unsigned int);
- char *(*objsearch) (const char *, uintptr_t *, unsigned int);
- unsigned int (*objopen) (struct link_map *, Lmid_t, uintptr_t *);
- void (*preinit) (uintptr_t *);
- union
- {
- uintptr_t (*symbind32) (Elf32_Sym *, unsigned int, uintptr_t *,
- uintptr_t *, unsigned int *, const char *);
- uintptr_t (*symbind64) (Elf64_Sym *, unsigned int, uintptr_t *,
- uintptr_t *, unsigned int *, const char *);
- };
- union
- {
- #ifdef ARCH_PLTENTER_MEMBERS
- ARCH_PLTENTER_MEMBERS;
- #endif
- };
- union
- {
- #ifdef ARCH_PLTEXIT_MEMBERS
- ARCH_PLTEXIT_MEMBERS;
- #endif
- };
- unsigned int (*objclose) (uintptr_t *);
- struct audit_ifaces *next;
- };
- /* Test whether given NAME matches any of the names of the given object. */
- extern int _dl_name_match_p (const char *__name, const struct link_map *__map)
- attribute_hidden;
- /* Compute next higher prime number. */
- extern unsigned long int _dl_higher_prime_number (unsigned long int n)
- attribute_hidden;
- /* A stripped down strtoul-like implementation. */
- uint64_t _dl_strtoul (const char *, char **) attribute_hidden;
- /* Function used as argument for `_dl_receive_error' function. The
- arguments are the error code, error string, and the objname the
- error occurred in. */
- typedef void (*receiver_fct) (int, const char *, const char *);
- /* Internal functions of the run-time dynamic linker.
- These can be accessed if you link again the dynamic linker
- as a shared library, as in `-lld' or `/lib/ld.so' explicitly;
- but are not normally of interest to user programs.
- The `-ldl' library functions in <dlfcn.h> provide a simple
- user interface to run-time dynamic linking. */
- #ifndef SHARED
- # define EXTERN extern
- # define GL(name) _##name
- #else
- # define EXTERN
- # if IS_IN (rtld)
- # define GL(name) _rtld_local._##name
- # else
- # define GL(name) _rtld_global._##name
- # endif
- struct rtld_global
- {
- #endif
- /* Don't change the order of the following elements. 'dl_loaded'
- must remain the first element. Forever. */
- /* Non-shared code has no support for multiple namespaces. */
- #ifdef SHARED
- # define DL_NNS 16
- #else
- # define DL_NNS 1
- #endif
- EXTERN struct link_namespaces
- {
- /* A pointer to the map for the main map. */
- struct link_map *_ns_loaded;
- /* Number of object in the _dl_loaded list. */
- unsigned int _ns_nloaded;
- /* Direct pointer to the searchlist of the main object. */
- struct r_scope_elem *_ns_main_searchlist;
- /* This is zero at program start to signal that the global scope map is
- allocated by rtld. Later it keeps the size of the map. It might be
- reset if in _dl_close if the last global object is removed. */
- size_t _ns_global_scope_alloc;
- /* Search table for unique objects. */
- struct unique_sym_table
- {
- __rtld_lock_define_recursive (, lock)
- struct unique_sym
- {
- uint32_t hashval;
- const char *name;
- const ElfW(Sym) *sym;
- const struct link_map *map;
- } *entries;
- size_t size;
- size_t n_elements;
- void (*free) (void *);
- } _ns_unique_sym_table;
- /* Keep track of changes to each namespace' list. */
- struct r_debug _ns_debug;
- } _dl_ns[DL_NNS];
- /* One higher than index of last used namespace. */
- EXTERN size_t _dl_nns;
- /* During the program run we must not modify the global data of
- loaded shared object simultanously in two threads. Therefore we
- protect `_dl_open' and `_dl_close' in dl-close.c.
- This must be a recursive lock since the initializer function of
- the loaded object might as well require a call to this function.
- At this time it is not anymore a problem to modify the tables. */
- __rtld_lock_define_recursive (EXTERN, _dl_load_lock)
- /* This lock is used to keep __dl_iterate_phdr from inspecting the
- list of loaded objects while an object is added to or removed
- from that list. */
- __rtld_lock_define_recursive (EXTERN, _dl_load_write_lock)
- /* Incremented whenever something may have been added to dl_loaded. */
- EXTERN unsigned long long _dl_load_adds;
- /* The object to be initialized first. */
- EXTERN struct link_map *_dl_initfirst;
- #if HP_SMALL_TIMING_AVAIL
- /* Start time on CPU clock. */
- EXTERN hp_timing_t _dl_cpuclock_offset;
- #endif
- /* Map of shared object to be profiled. */
- EXTERN struct link_map *_dl_profile_map;
- /* Counters for the number of relocations performed. */
- EXTERN unsigned long int _dl_num_relocations;
- EXTERN unsigned long int _dl_num_cache_relocations;
- /* List of search directories. */
- EXTERN struct r_search_path_elem *_dl_all_dirs;
- /* Structure describing the dynamic linker itself. We need to
- reserve memory for the data the audit libraries need. */
- EXTERN struct link_map _dl_rtld_map;
- #ifdef SHARED
- struct auditstate audit_data[DL_NNS];
- #endif
- #if defined SHARED && defined _LIBC_REENTRANT \
- && defined __rtld_lock_default_lock_recursive
- EXTERN void (*_dl_rtld_lock_recursive) (void *);
- EXTERN void (*_dl_rtld_unlock_recursive) (void *);
- #endif
- /* Get architecture specific definitions. */
- #define PROCINFO_DECL
- #ifndef PROCINFO_CLASS
- # define PROCINFO_CLASS EXTERN
- #endif
- #include <dl-procruntime.c>
- /* If loading a shared object requires that we make the stack executable
- when it was not, we do it by calling this function.
- It returns an errno code or zero on success. */
- EXTERN int (*_dl_make_stack_executable_hook) (void **);
- /* Prevailing state of the stack, PF_X indicating it's executable. */
- EXTERN ElfW(Word) _dl_stack_flags;
- /* Flag signalling whether there are gaps in the module ID allocation. */
- EXTERN bool _dl_tls_dtv_gaps;
- /* Highest dtv index currently needed. */
- EXTERN size_t _dl_tls_max_dtv_idx;
- /* Information about the dtv slots. */
- EXTERN struct dtv_slotinfo_list
- {
- size_t len;
- struct dtv_slotinfo_list *next;
- struct dtv_slotinfo
- {
- size_t gen;
- struct link_map *map;
- } slotinfo[0];
- } *_dl_tls_dtv_slotinfo_list;
- /* Number of modules in the static TLS block. */
- EXTERN size_t _dl_tls_static_nelem;
- /* Size of the static TLS block. */
- EXTERN size_t _dl_tls_static_size;
- /* Size actually allocated in the static TLS block. */
- EXTERN size_t _dl_tls_static_used;
- /* Alignment requirement of the static TLS block. */
- EXTERN size_t _dl_tls_static_align;
- /* Number of additional entries in the slotinfo array of each slotinfo
- list element. A large number makes it almost certain take we never
- have to iterate beyond the first element in the slotinfo list. */
- #define TLS_SLOTINFO_SURPLUS (62)
- /* Number of additional slots in the dtv allocated. */
- #define DTV_SURPLUS (14)
- /* Initial dtv of the main thread, not allocated with normal malloc. */
- EXTERN void *_dl_initial_dtv;
- /* Generation counter for the dtv. */
- EXTERN size_t _dl_tls_generation;
- EXTERN void (*_dl_init_static_tls) (struct link_map *);
- EXTERN void (*_dl_wait_lookup_done) (void);
- /* Scopes to free after next THREAD_GSCOPE_WAIT (). */
- EXTERN struct dl_scope_free_list
- {
- size_t count;
- void *list[50];
- } *_dl_scope_free_list;
- #if !THREAD_GSCOPE_IN_TCB
- EXTERN int _dl_thread_gscope_count;
- #endif
- #ifdef SHARED
- };
- # define __rtld_global_attribute__
- # if IS_IN (rtld)
- # ifdef HAVE_SDATA_SECTION
- # define __rtld_local_attribute__ \
- __attribute__ ((visibility ("hidden"), section (".sdata")))
- # undef __rtld_global_attribute__
- # define __rtld_global_attribute__ __attribute__ ((section (".sdata")))
- # else
- # define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
- # endif
- extern struct rtld_global _rtld_local __rtld_local_attribute__;
- # undef __rtld_local_attribute__
- # endif
- extern struct rtld_global _rtld_global __rtld_global_attribute__;
- # undef __rtld_global_attribute__
- #endif
- #ifndef SHARED
- # define GLRO(name) _##name
- #else
- # if IS_IN (rtld)
- # define GLRO(name) _rtld_local_ro._##name
- # else
- # define GLRO(name) _rtld_global_ro._##name
- # endif
- struct rtld_global_ro
- {
- #endif
- /* If nonzero the appropriate debug information is printed. */
- EXTERN int _dl_debug_mask;
- #define DL_DEBUG_LIBS (1 << 0)
- #define DL_DEBUG_IMPCALLS (1 << 1)
- #define DL_DEBUG_BINDINGS (1 << 2)
- #define DL_DEBUG_SYMBOLS (1 << 3)
- #define DL_DEBUG_VERSIONS (1 << 4)
- #define DL_DEBUG_RELOC (1 << 5)
- #define DL_DEBUG_FILES (1 << 6)
- #define DL_DEBUG_STATISTICS (1 << 7)
- #define DL_DEBUG_UNUSED (1 << 8)
- #define DL_DEBUG_SCOPES (1 << 9)
- /* These two are used only internally. */
- #define DL_DEBUG_HELP (1 << 10)
- #define DL_DEBUG_PRELINK (1 << 11)
- /* OS version. */
- EXTERN unsigned int _dl_osversion;
- /* Platform name. */
- EXTERN const char *_dl_platform;
- EXTERN size_t _dl_platformlen;
- /* Cached value of `getpagesize ()'. */
- EXTERN size_t _dl_pagesize;
- /* Do we read from ld.so.cache? */
- EXTERN int _dl_inhibit_cache;
- /* Copy of the content of `_dl_main_searchlist' at startup time. */
- EXTERN struct r_scope_elem _dl_initial_searchlist;
- /* CLK_TCK as reported by the kernel. */
- EXTERN int _dl_clktck;
- /* If nonzero print warnings messages. */
- EXTERN int _dl_verbose;
- /* File descriptor to write debug messages to. */
- EXTERN int _dl_debug_fd;
- /* Do we do lazy relocations? */
- EXTERN int _dl_lazy;
- /* Nonzero if runtime lookups should not update the .got/.plt. */
- EXTERN int _dl_bind_not;
- /* Nonzero if references should be treated as weak during runtime
- linking. */
- EXTERN int _dl_dynamic_weak;
- /* Default floating-point control word. */
- EXTERN fpu_control_t _dl_fpu_control;
- /* Expected cache ID. */
- EXTERN int _dl_correct_cache_id;
- /* Mask for hardware capabilities that are available. */
- EXTERN uint64_t _dl_hwcap;
- #if !HAVE_TUNABLES
- /* Mask for important hardware capabilities we honour. */
- EXTERN uint64_t _dl_hwcap_mask;
- #endif
- #ifdef HAVE_AUX_VECTOR
- /* Pointer to the auxv list supplied to the program at startup. */
- EXTERN ElfW(auxv_t) *_dl_auxv;
- #endif
- /* Get architecture specific definitions. */
- #include <dl-procinfo.c>
- /* Names of shared object for which the RPATH should be ignored. */
- EXTERN const char *_dl_inhibit_rpath;
- /* Location of the binary. */
- EXTERN const char *_dl_origin_path;
- /* -1 if the dynamic linker should honor library load bias,
- 0 if not, -2 use the default (honor biases for normal
- binaries, don't honor for PIEs). */
- EXTERN ElfW(Addr) _dl_use_load_bias;
- /* Name of the shared object to be profiled (if any). */
- EXTERN const char *_dl_profile;
- /* Filename of the output file. */
- EXTERN const char *_dl_profile_output;
- /* Name of the object we want to trace the prelinking. */
- EXTERN const char *_dl_trace_prelink;
- /* Map of shared object to be prelink traced. */
- EXTERN struct link_map *_dl_trace_prelink_map;
- /* All search directories defined at startup. This is assigned a
- non-NULL pointer by the ld.so startup code (after initialization
- to NULL), so this can also serve as an indicator whether a copy
- of ld.so is initialized and active. See the rtld_active function
- below. */
- EXTERN struct r_search_path_elem *_dl_init_all_dirs;
- #ifdef NEED_DL_SYSINFO
- /* Syscall handling improvements. This is very specific to x86. */
- EXTERN uintptr_t _dl_sysinfo;
- #endif
- #ifdef NEED_DL_SYSINFO_DSO
- /* The vsyscall page is a virtual DSO pre-mapped by the kernel.
- This points to its ELF header. */
- EXTERN const ElfW(Ehdr) *_dl_sysinfo_dso;
- /* At startup time we set up the normal DSO data structure for it,
- and this points to it. */
- EXTERN struct link_map *_dl_sysinfo_map;
- #endif
- /* Mask for more hardware capabilities that are available on some
- platforms. */
- EXTERN uint64_t _dl_hwcap2;
- #ifdef SHARED
- /* We add a function table to _rtld_global which is then used to
- call the function instead of going through the PLT. The result
- is that we can avoid exporting the functions and we do not jump
- PLT relocations in libc.so. */
- void (*_dl_debug_printf) (const char *, ...)
- __attribute__ ((__format__ (__printf__, 1, 2)));
- void (*_dl_mcount) (ElfW(Addr) frompc, ElfW(Addr) selfpc);
- lookup_t (*_dl_lookup_symbol_x) (const char *, struct link_map *,
- const ElfW(Sym) **, struct r_scope_elem *[],
- const struct r_found_version *, int, int,
- struct link_map *);
- void *(*_dl_open) (const char *file, int mode, const void *caller_dlopen,
- Lmid_t nsid, int argc, char *argv[], char *env[]);
- void (*_dl_close) (void *map);
- void *(*_dl_tls_get_addr_soft) (struct link_map *);
- #ifdef HAVE_DL_DISCOVER_OSVERSION
- int (*_dl_discover_osversion) (void);
- #endif
- /* List of auditing interfaces. */
- struct audit_ifaces *_dl_audit;
- unsigned int _dl_naudit;
- };
- # define __rtld_global_attribute__
- # if IS_IN (rtld)
- # define __rtld_local_attribute__ __attribute__ ((visibility ("hidden")))
- extern struct rtld_global_ro _rtld_local_ro
- attribute_relro __rtld_local_attribute__;
- extern struct rtld_global_ro _rtld_global_ro
- attribute_relro __rtld_global_attribute__;
- # undef __rtld_local_attribute__
- # else
- /* We cheat a bit here. We declare the variable as as const even
- though it is at startup. */
- extern const struct rtld_global_ro _rtld_global_ro
- attribute_relro __rtld_global_attribute__;
- # endif
- # undef __rtld_global_attribute__
- #endif
- #undef EXTERN
- #ifndef SHARED
- /* dl-support.c defines these and initializes them early on. */
- extern const ElfW(Phdr) *_dl_phdr;
- extern size_t _dl_phnum;
- #endif
- /* This is the initial value of GL(dl_make_stack_executable_hook).
- A threads library can change it. */
- extern int _dl_make_stack_executable (void **stack_endp);
- rtld_hidden_proto (_dl_make_stack_executable)
- /* Variable pointing to the end of the stack (or close to it). This value
- must be constant over the runtime of the application. Some programs
- might use the variable which results in copy relocations on some
- platforms. But this does not matter, ld.so can always use the local
- copy. */
- extern void *__libc_stack_end
- #ifndef LIBC_STACK_END_NOT_RELRO
- attribute_relro
- #endif
- ;
- rtld_hidden_proto (__libc_stack_end)
- /* Parameters passed to the dynamic linker. */
- extern int _dl_argc attribute_hidden attribute_relro;
- extern char **_dl_argv
- #ifndef DL_ARGV_NOT_RELRO
- attribute_relro
- #endif
- ;
- rtld_hidden_proto (_dl_argv)
- #if IS_IN (rtld)
- extern unsigned int _dl_skip_args attribute_hidden
- # ifndef DL_ARGV_NOT_RELRO
- attribute_relro
- # endif
- ;
- extern unsigned int _dl_skip_args_internal attribute_hidden
- # ifndef DL_ARGV_NOT_RELRO
- attribute_relro
- # endif
- ;
- #endif
- #define rtld_progname _dl_argv[0]
- /* Flag set at startup and cleared when the last initializer has run. */
- extern int _dl_starting_up;
- weak_extern (_dl_starting_up)
- rtld_hidden_proto (_dl_starting_up)
- /* Random data provided by the kernel. */
- extern void *_dl_random attribute_hidden attribute_relro;
- /* OS-dependent function to open the zero-fill device. */
- extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */
- /* Write message on the debug file descriptor. The parameters are
- interpreted as for a `printf' call. All the lines start with a
- tag showing the PID. */
- extern void _dl_debug_printf (const char *fmt, ...)
- __attribute__ ((__format__ (__printf__, 1, 2))) attribute_hidden;
- /* Write message on the debug file descriptor. The parameters are
- interpreted as for a `printf' call. All the lines buf the first
- start with a tag showing the PID. */
- extern void _dl_debug_printf_c (const char *fmt, ...)
- __attribute__ ((__format__ (__printf__, 1, 2))) attribute_hidden;
- /* Write a message on the specified descriptor FD. The parameters are
- interpreted as for a `printf' call. */
- #if IS_IN (rtld) || !defined (SHARED)
- extern void _dl_dprintf (int fd, const char *fmt, ...)
- __attribute__ ((__format__ (__printf__, 2, 3)))
- attribute_hidden;
- #else
- __attribute__ ((always_inline, __format__ (__printf__, 2, 3)))
- static inline void
- _dl_dprintf (int fd, const char *fmt, ...)
- {
- /* Use local declaration to avoid includign <stdio.h>. */
- extern int __dprintf(int fd, const char *format, ...) attribute_hidden;
- __dprintf (fd, fmt, __builtin_va_arg_pack ());
- }
- #endif
- /* Write a message on the specified descriptor standard output. The
- parameters are interpreted as for a `printf' call. */
- #define _dl_printf(fmt, args...) \
- _dl_dprintf (STDOUT_FILENO, fmt, ##args)
- /* Write a message on the specified descriptor standard error. The
- parameters are interpreted as for a `printf' call. */
- #define _dl_error_printf(fmt, args...) \
- _dl_dprintf (STDERR_FILENO, fmt, ##args)
- /* Write a message on the specified descriptor standard error and exit
- the program. The parameters are interpreted as for a `printf' call. */
- #define _dl_fatal_printf(fmt, args...) \
- do \
- { \
- _dl_dprintf (STDERR_FILENO, fmt, ##args); \
- _exit (127); \
- } \
- while (1)
- /* An exception raised by the _dl_signal_error function family and
- caught by _dl_catch_error function family. Exceptions themselves
- are copied as part of the raise operation, but the strings are
- not. */
- struct dl_exception
- {
- const char *objname;
- const char *errstring;
- /* This buffer typically stores both objname and errstring
- above. */
- char *message_buffer;
- };
- /* Creates a new exception. This calls malloc; if allocation fails,
- dummy values are inserted. OBJECT is the name of the problematical
- shared object, or null if its a general problem. ERRSTRING is a
- string describing the specific problem. */
- void _dl_exception_create (struct dl_exception *, const char *object,
- const char *errstring)
- __attribute__ ((nonnull (1, 3)));
- rtld_hidden_proto (_dl_exception_create)
- /* Like _dl_exception_create, but create errstring from a format
- string FMT. Currently, only "%s" and "%%" are supported as format
- directives. */
- void _dl_exception_create_format (struct dl_exception *, const char *objname,
- const char *fmt, ...)
- __attribute__ ((nonnull (1, 3), format (printf, 3, 4)));
- rtld_hidden_proto (_dl_exception_create_format)
- /* Deallocate the exception, freeing allocated buffers (if
- possible). */
- void _dl_exception_free (struct dl_exception *)
- __attribute__ ((nonnull (1)));
- rtld_hidden_proto (_dl_exception_free)
- /* This function is called by all the internal dynamic linker
- functions when they encounter an error. ERRCODE is either an
- `errno' code or zero; it specifies the return value of
- _dl_catch_error. OCCASION is included in the error message if the
- process is terminated immediately. */
- void _dl_signal_exception (int errcode, struct dl_exception *,
- const char *occasion)
- __attribute__ ((__noreturn__));
- libc_hidden_proto (_dl_signal_exception)
- /* Like _dl_signal_exception, but creates the exception first. */
- extern void _dl_signal_error (int errcode, const char *object,
- const char *occasion, const char *errstring)
- __attribute__ ((__noreturn__));
- libc_hidden_proto (_dl_signal_error)
- /* Like _dl_signal_exception, but may return when called in the
- context of _dl_receive_error. This is only used during ld.so
- bootstrap. In static and profiled builds, this is equivalent to
- _dl_signal_exception. */
- #if IS_IN (rtld)
- extern void _dl_signal_cexception (int errcode, struct dl_exception *,
- const char *occasion) attribute_hidden;
- #else
- __attribute__ ((always_inline))
- static inline void
- _dl_signal_cexception (int errcode, struct dl_exception *exception,
- const char *occasion)
- {
- _dl_signal_exception (errcode, exception, occasion);
- }
- #endif
- /* See _dl_signal_cexception above. */
- #if IS_IN (rtld)
- extern void _dl_signal_cerror (int errcode, const char *object,
- const char *occasion, const char *errstring)
- attribute_hidden;
- #else
- __attribute__ ((always_inline))
- static inline void
- _dl_signal_cerror (int errcode, const char *object,
- const char *occasion, const char *errstring)
- {
- _dl_signal_error (errcode, object, occasion, errstring);
- }
- #endif
- /* Call OPERATE, receiving errors from `dl_signal_cerror'. Unlike
- `_dl_catch_error' the operation is resumed after the OPERATE
- function returns.
- ARGS is passed as argument to OPERATE. */
- extern void _dl_receive_error (receiver_fct fct, void (*operate) (void *),
- void *args) attribute_hidden;
- /* Call OPERATE, catching errors from `_dl_signal_error' and related
- functions. If there is no error, *ERRSTRING is set to null. If
- there is an error, *ERRSTRING is set to a string constructed from
- the strings passed to _dl_signal_error, and the error code passed
- is the return value and *OBJNAME is set to the object name which
- experienced the problems. ERRSTRING if nonzero points to a
- malloc'ed string which the caller has to free after use. ARGS is
- passed as argument to OPERATE. MALLOCEDP is set to true only if
- the returned string is allocated using the libc's malloc. */
- extern int _dl_catch_error (const char **objname, const char **errstring,
- bool *mallocedp, void (*operate) (void *),
- void *args);
- libc_hidden_proto (_dl_catch_error)
- /* Call OPERATE (ARGS). If no error occurs, set *EXCEPTION to zero.
- Otherwise, store a copy of the raised exception in *EXCEPTION,
- which has to be freed by _dl_exception_free. */
- int _dl_catch_exception (struct dl_exception *exception,
- void (*operate) (void *), void *args);
- libc_hidden_proto (_dl_catch_exception)
- /* Open the shared object NAME and map in its segments.
- LOADER's DT_RPATH is used in searching for NAME.
- If the object is already opened, returns its existing map. */
- extern struct link_map *_dl_map_object (struct link_map *loader,
- const char *name,
- int type, int trace_mode, int mode,
- Lmid_t nsid) attribute_hidden;
- /* Call _dl_map_object on the dependencies of MAP, and set up
- MAP->l_searchlist. PRELOADS points to a vector of NPRELOADS previously
- loaded objects that will be inserted into MAP->l_searchlist after MAP
- but before its dependencies. */
- extern void _dl_map_object_deps (struct link_map *map,
- struct link_map **preloads,
- unsigned int npreloads, int trace_mode,
- int open_mode)
- attribute_hidden;
- /* Cache the locations of MAP's hash table. */
- extern void _dl_setup_hash (struct link_map *map) attribute_hidden;
- /* Collect the directories in the search path for LOADER's dependencies.
- The data structure is defined in <dlfcn.h>. If COUNTING is true,
- SI->dls_cnt and SI->dls_size are set; if false, those must be as set
- by a previous call with COUNTING set, and SI must point to SI->dls_size
- bytes to be used in filling in the result. */
- extern void _dl_rtld_di_serinfo (struct link_map *loader,
- Dl_serinfo *si, bool counting);
- /* Search loaded objects' symbol tables for a definition of the symbol
- referred to by UNDEF. *SYM is the symbol table entry containing the
- reference; it is replaced with the defining symbol, and the base load
- address of the defining object is returned. SYMBOL_SCOPE is a
- null-terminated list of object scopes to search; each object's
- l_searchlist (i.e. the segment of the dependency tree starting at that
- object) is searched in turn. REFERENCE_NAME should name the object
- containing the reference; it is used in error messages.
- TYPE_CLASS describes the type of symbol we are looking for. */
- enum
- {
- /* If necessary add dependency between user and provider object. */
- DL_LOOKUP_ADD_DEPENDENCY = 1,
- /* Return most recent version instead of default version for
- unversioned lookup. */
- DL_LOOKUP_RETURN_NEWEST = 2,
- /* Set if dl_lookup* called with GSCOPE lock held. */
- DL_LOOKUP_GSCOPE_LOCK = 4,
- };
- /* Lookup versioned symbol. */
- extern lookup_t _dl_lookup_symbol_x (const char *undef,
- struct link_map *undef_map,
- const ElfW(Sym) **sym,
- struct r_scope_elem *symbol_scope[],
- const struct r_found_version *version,
- int type_class, int flags,
- struct link_map *skip_map)
- attribute_hidden;
- /* Add the new link_map NEW to the end of the namespace list. */
- extern void _dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid)
- attribute_hidden;
- /* Allocate a `struct link_map' for a new object being loaded. */
- extern struct link_map *_dl_new_object (char *realname, const char *libname,
- int type, struct link_map *loader,
- int mode, Lmid_t nsid)
- attribute_hidden;
- /* Relocate the given object (if it hasn't already been).
- SCOPE is passed to _dl_lookup_symbol in symbol lookups.
- If RTLD_LAZY is set in RELOC-MODE, don't relocate its PLT. */
- extern void _dl_relocate_object (struct link_map *map,
- struct r_scope_elem *scope[],
- int reloc_mode, int consider_profiling)
- attribute_hidden;
- /* Protect PT_GNU_RELRO area. */
- extern void _dl_protect_relro (struct link_map *map) attribute_hidden;
- /* Call _dl_signal_error with a message about an unhandled reloc type.
- TYPE is the result of ELFW(R_TYPE) (r_info), i.e. an R_<CPU>_* value.
- PLT is nonzero if this was a PLT reloc; it just affects the message. */
- extern void _dl_reloc_bad_type (struct link_map *map,
- unsigned int type, int plt)
- attribute_hidden __attribute__ ((__noreturn__));
- /* Resolve conflicts if prelinking. */
- extern void _dl_resolve_conflicts (struct link_map *l,
- ElfW(Rela) *conflict,
- ElfW(Rela) *conflictend)
- attribute_hidden;
- /* Check the version dependencies of all objects available through
- MAP. If VERBOSE print some more diagnostics. */
- extern int _dl_check_all_versions (struct link_map *map, int verbose,
- int trace_mode) attribute_hidden;
- /* Check the version dependencies for MAP. If VERBOSE print some more
- diagnostics. */
- extern int _dl_check_map_versions (struct link_map *map, int verbose,
- int trace_mode) attribute_hidden;
- /* Initialize the object in SCOPE by calling the constructors with
- ARGC, ARGV, and ENV as the parameters. */
- extern void _dl_init (struct link_map *main_map, int argc, char **argv,
- char **env) attribute_hidden;
- /* Call the finalizer functions of all shared objects whose
- initializer functions have completed. */
- extern void _dl_fini (void) attribute_hidden;
- /* Sort array MAPS according to dependencies of the contained objects. */
- extern void _dl_sort_maps (struct link_map **maps, unsigned int nmaps,
- char *used, bool for_fini) attribute_hidden;
- /* The dynamic linker calls this function before and having changing
- any shared object mappings. The `r_state' member of `struct r_debug'
- says what change is taking place. This function's address is
- the value of the `r_brk' member. */
- extern void _dl_debug_state (void);
- rtld_hidden_proto (_dl_debug_state)
- /* Initialize `struct r_debug' if it has not already been done. The
- argument is the run-time load address of the dynamic linker, to be put
- in the `r_ldbase' member. Returns the address of the structure. */
- extern struct r_debug *_dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
- attribute_hidden;
- /* Initialize the basic data structure for the search paths. */
- extern void _dl_init_paths (const char *library_path) attribute_hidden;
- /* Gather the information needed to install the profiling tables and start
- the timers. */
- extern void _dl_start_profile (void) attribute_hidden;
- /* The actual functions used to keep book on the calls. */
- extern void _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc);
- rtld_hidden_proto (_dl_mcount)
- /* This function is simply a wrapper around the _dl_mcount function
- which does not require a FROMPC parameter since this is the
- calling function. */
- extern void _dl_mcount_wrapper (void *selfpc);
- /* Show the members of the auxiliary array passed up from the kernel. */
- extern void _dl_show_auxv (void) attribute_hidden;
- /* Return all environment variables starting with `LD_', one after the
- other. */
- extern char *_dl_next_ld_env_entry (char ***position) attribute_hidden;
- /* Return an array with the names of the important hardware capabilities. */
- extern const struct r_strlenpair *_dl_important_hwcaps (const char *platform,
- size_t paltform_len,
- size_t *sz,
- size_t *max_capstrlen)
- attribute_hidden;
- /* Look up NAME in ld.so.cache and return the file name stored there,
- or null if none is found. Caller must free returned string. */
- extern char *_dl_load_cache_lookup (const char *name) attribute_hidden;
- /* If the system does not support MAP_COPY we cannot leave the file open
- all the time since this would create problems when the file is replaced.
- Therefore we provide this function to close the file and open it again
- once needed. */
- extern void _dl_unload_cache (void) attribute_hidden;
- /* System-dependent function to read a file's whole contents in the
- most convenient manner available. *SIZEP gets the size of the
- file. On error MAP_FAILED is returned. */
- extern void *_dl_sysdep_read_whole_file (const char *file, size_t *sizep,
- int prot) attribute_hidden;
- /* System-specific function to do initial startup for the dynamic linker.
- After this, file access calls and getenv must work. This is responsible
- for setting __libc_enable_secure if we need to be secure (e.g. setuid),
- and for setting _dl_argc and _dl_argv, and then calling _dl_main. */
- extern ElfW(Addr) _dl_sysdep_start (void **start_argptr,
- void (*dl_main) (const ElfW(Phdr) *phdr,
- ElfW(Word) phnum,
- ElfW(Addr) *user_entry,
- ElfW(auxv_t) *auxv))
- attribute_hidden;
- extern void _dl_sysdep_start_cleanup (void) attribute_hidden;
- /* Determine next available module ID. */
- extern size_t _dl_next_tls_modid (void) attribute_hidden;
- /* Count the modules with TLS segments. */
- extern size_t _dl_count_modids (void) attribute_hidden;
- /* Calculate offset of the TLS blocks in the static TLS block. */
- extern void _dl_determine_tlsoffset (void) attribute_hidden;
- #ifndef SHARED
- /* Set up the TCB for statically linked applications. This is called
- early during startup because we always use TLS (for errno and the
- stack protector, among other things). */
- void __libc_setup_tls (void);
- # if ENABLE_STATIC_PIE
- /* Relocate static executable with PIE. */
- extern void _dl_relocate_static_pie (void) attribute_hidden;
- /* Get a pointer to _dl_main_map. */
- extern struct link_map * _dl_get_dl_main_map (void)
- __attribute__ ((visibility ("hidden")));
- # else
- # define _dl_relocate_static_pie()
- # endif
- #endif
- /* Initialization of libpthread for statically linked applications.
- If libpthread is not linked in, this is an empty function. */
- void __pthread_initialize_minimal (void) weak_function;
- /* Allocate memory for static TLS block (unless MEM is nonzero) and dtv. */
- extern void *_dl_allocate_tls (void *mem);
- rtld_hidden_proto (_dl_allocate_tls)
- /* Get size and alignment requirements of the static TLS block. */
- extern void _dl_get_tls_static_info (size_t *sizep, size_t *alignp);
- extern void _dl_allocate_static_tls (struct link_map *map) attribute_hidden;
- /* These are internal entry points to the two halves of _dl_allocate_tls,
- only used within rtld.c itself at startup time. */
- extern void *_dl_allocate_tls_storage (void) attribute_hidden;
- extern void *_dl_allocate_tls_init (void *);
- rtld_hidden_proto (_dl_allocate_tls_init)
- /* Deallocate memory allocated with _dl_allocate_tls. */
- extern void _dl_deallocate_tls (void *tcb, bool dealloc_tcb);
- rtld_hidden_proto (_dl_deallocate_tls)
- extern void _dl_nothread_init_static_tls (struct link_map *) attribute_hidden;
- /* Find origin of the executable. */
- extern const char *_dl_get_origin (void) attribute_hidden;
- /* Count DSTs. */
- extern size_t _dl_dst_count (const char *name) attribute_hidden;
- /* Substitute DST values. */
- extern char *_dl_dst_substitute (struct link_map *l, const char *name,
- char *result) attribute_hidden;
- /* Open the shared object NAME, relocate it, and run its initializer if it
- hasn't already been run. MODE is as for `dlopen' (see <dlfcn.h>). If
- the object is already opened, returns its existing map. */
- extern void *_dl_open (const char *name, int mode, const void *caller,
- Lmid_t nsid, int argc, char *argv[], char *env[])
- attribute_hidden;
- /* Free or queue for freeing scope OLD. If other threads might be
- in the middle of _dl_fixup, _dl_profile_fixup or dl*sym using the
- old scope, OLD can't be freed until no thread is using it. */
- extern int _dl_scope_free (void *) attribute_hidden;
- /* Add module to slot information data. */
- extern void _dl_add_to_slotinfo (struct link_map *l) attribute_hidden;
- /* Update slot information data for at least the generation of the
- module with the given index. */
- extern struct link_map *_dl_update_slotinfo (unsigned long int req_modid)
- attribute_hidden;
- /* Look up the module's TLS block as for __tls_get_addr,
- but never touch anything. Return null if it's not allocated yet. */
- extern void *_dl_tls_get_addr_soft (struct link_map *l) attribute_hidden;
- extern int _dl_addr_inside_object (struct link_map *l, const ElfW(Addr) addr)
- attribute_hidden;
- /* Show show of an object. */
- extern void _dl_show_scope (struct link_map *new, int from)
- attribute_hidden;
- extern struct link_map *_dl_find_dso_for_object (const ElfW(Addr) addr);
- rtld_hidden_proto (_dl_find_dso_for_object)
- /* Initialization which is normally done by the dynamic linker. */
- extern void _dl_non_dynamic_init (void)
- attribute_hidden;
- /* Used by static binaries to check the auxiliary vector. */
- extern void _dl_aux_init (ElfW(auxv_t) *av)
- attribute_hidden;
- /* Return true if the ld.so copy in this namespace is actually active
- and working. If false, the dl_open/dlfcn hooks have to be used to
- call into the outer dynamic linker (which happens after static
- dlopen). */
- #ifdef SHARED
- static inline bool
- rtld_active (void)
- {
- /* The default-initialized variable does not have a non-zero
- dl_init_all_dirs member, so this allows us to recognize an
- initialized and active ld.so copy. */
- return GLRO(dl_init_all_dirs) != NULL;
- }
- #endif
- __END_DECLS
- #endif /* ldsodefs.h */
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