/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef RTLD_H /* { */ #define RTLD_H 1 #include #include #include #include #include #include #include #include #include #include "rtld_lock.h" #include "rtld_machdep.h" #define NEW(type) ((type *) xmalloc(sizeof(type))) #define CNEW(type) ((type *) xcalloc(1, sizeof(type))) extern size_t tls_last_offset; extern size_t tls_last_size; extern size_t tls_static_space; extern Elf_Addr tls_dtv_generation; extern int tls_max_index; extern size_t ld_static_tls_extra; extern int npagesizes; extern size_t *pagesizes; extern size_t page_size; extern int main_argc; extern char **main_argv; extern char **environ; struct stat; struct Struct_Obj_Entry; /* Lists of shared objects */ typedef struct Struct_Objlist_Entry { STAILQ_ENTRY(Struct_Objlist_Entry) link; struct Struct_Obj_Entry *obj; } Objlist_Entry; typedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; /* Types of init and fini functions */ typedef void (*InitFunc)(void); typedef void (*InitArrFunc)(int, char **, char **); /* Lists of shared object dependencies */ typedef struct Struct_Needed_Entry { struct Struct_Needed_Entry *next; struct Struct_Obj_Entry *obj; unsigned long name; /* Offset of name in string table */ } Needed_Entry; typedef struct Struct_Name_Entry { STAILQ_ENTRY(Struct_Name_Entry) link; char name[1]; } Name_Entry; /* Lock object */ typedef struct Struct_LockInfo { void *context; /* Client context for creating locks */ void *thelock; /* The one big lock */ /* Debugging aids. */ volatile int rcount; /* Number of readers holding lock */ volatile int wcount; /* Number of writers holding lock */ /* Methods */ void *(*lock_create)(void *context); void (*rlock_acquire)(void *lock); void (*wlock_acquire)(void *lock); void (*rlock_release)(void *lock); void (*wlock_release)(void *lock); void (*lock_destroy)(void *lock); void (*context_destroy)(void *context); } LockInfo; typedef struct Struct_Ver_Entry { Elf_Word hash; unsigned int flags; const char *name; const char *file; } Ver_Entry; typedef struct Struct_Sym_Match_Result { const Elf_Sym *sym_out; const Elf_Sym *vsymp; int vcount; } Sym_Match_Result; #define VER_INFO_HIDDEN 0x01 /* * Shared object descriptor. * * Items marked with "(%)" are dynamically allocated, and must be freed * when the structure is destroyed. * * CAUTION: It appears that the JDK port peeks into these structures. * It looks at "next" and "mapbase" at least. Don't add new members * near the front, until this can be straightened out. */ typedef struct Struct_Obj_Entry { /* * These two items have to be set right for compatibility with the * original ElfKit crt1.o. */ Elf_Size magic; /* Magic number (sanity check) */ Elf_Size version; /* Version number of struct format */ TAILQ_ENTRY(Struct_Obj_Entry) next; char *path; /* Pathname of underlying file (%) */ char *origin_path; /* Directory path of origin file */ int refcount; /* DAG references */ int holdcount; /* Count of transient references */ int dl_refcount; /* Number of times loaded by dlopen */ /* These items are computed by map_object() or by digest_phdr(). */ caddr_t mapbase; /* Base address of mapped region */ size_t mapsize; /* Size of mapped region in bytes */ Elf_Addr vaddrbase; /* Base address in shared object file */ caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ const Elf_Dyn *dynamic; /* Dynamic section */ caddr_t entry; /* Entry point */ const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ size_t phsize; /* Size of program header in bytes */ const char *interp; /* Pathname of the interpreter, if any */ Elf_Word stack_flags; /* TLS information */ int tlsindex; /* Index in DTV for this module */ void *tlsinit; /* Base address of TLS init block */ size_t tlsinitsize; /* Size of TLS init block for this module */ size_t tlssize; /* Size of TLS block for this module */ size_t tlsoffset; /* Offset of static TLS block for this module */ size_t tlsalign; /* Alignment of static TLS block */ size_t tlspoffset; /* p_offset of the static TLS block */ caddr_t relro_page; size_t relro_size; /* Items from the dynamic section. */ Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ const Elf_Rel *rel; /* Relocation entries */ unsigned long relsize; /* Size in bytes of relocation info */ const Elf_Rela *rela; /* Relocation entries with addend */ unsigned long relasize; /* Size in bytes of addend relocation info */ const Elf_Relr *relr; /* RELR relocation entries */ unsigned long relrsize; /* Size in bytes of RELR relocations */ const Elf_Rel *pltrel; /* PLT relocation entries */ unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ const Elf_Rela *pltrela; /* PLT relocation entries with addend */ unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ const Elf_Sym *symtab; /* Symbol table */ const char *strtab; /* String table */ unsigned long strsize; /* Size in bytes of string table */ #ifdef __powerpc__ #ifdef __powerpc64__ Elf_Addr glink; /* GLINK PLT call stub section */ #else Elf_Addr *gotptr; /* GOT pointer (secure-plt only) */ #endif #endif const Elf_Verneed *verneed; /* Required versions. */ Elf_Word verneednum; /* Number of entries in verneed table */ const Elf_Verdef *verdef; /* Provided versions. */ Elf_Word verdefnum; /* Number of entries in verdef table */ const Elf_Versym *versyms; /* Symbol versions table */ const Elf_Hashelt *buckets; /* Hash table buckets array */ unsigned long nbuckets; /* Number of buckets */ const Elf_Hashelt *chains; /* Hash table chain array */ unsigned long nchains; /* Number of entries in chain array */ Elf32_Word nbuckets_gnu; /* Number of GNU hash buckets*/ Elf32_Word symndx_gnu; /* 1st accessible symbol on dynsym table */ Elf32_Word maskwords_bm_gnu; /* Bloom filter words - 1 (bitmask) */ Elf32_Word shift2_gnu; /* Bloom filter shift count */ Elf32_Word dynsymcount; /* Total entries in dynsym table */ const Elf_Addr *bloom_gnu; /* Bloom filter used by GNU hash func */ const Elf_Hashelt *buckets_gnu; /* GNU hash table bucket array */ const Elf_Hashelt *chain_zero_gnu; /* GNU hash table value array (Zeroed) */ const char *rpath; /* Search path specified in object */ const char *runpath; /* Search path with different priority */ Needed_Entry *needed; /* Shared objects needed by this one (%) */ Needed_Entry *needed_filtees; Needed_Entry *needed_aux_filtees; STAILQ_HEAD(, Struct_Name_Entry) names; /* List of names for this object we know about. */ Ver_Entry *vertab; /* Versions required /defined by this object */ int vernum; /* Number of entries in vertab */ Elf_Addr init; /* Initialization function to call */ Elf_Addr fini; /* Termination function to call */ Elf_Addr preinit_array; /* Pre-initialization array of functions */ Elf_Addr init_array; /* Initialization array of functions */ Elf_Addr fini_array; /* Termination array of functions */ int preinit_array_num; /* Number of entries in preinit_array */ int init_array_num; /* Number of entries in init_array */ int fini_array_num; /* Number of entries in fini_array */ int32_t osrel; /* OSREL note value */ uint32_t fctl0; /* FEATURE_CONTROL note desc[0] value */ bool mainprog : 1; /* True if this is the main program */ bool rtld : 1; /* True if this is the dynamic linker */ bool relocated : 1; /* True if processed by relocate_objects() */ bool ver_checked : 1; /* True if processed by rtld_verify_object_versions */ bool textrel : 1; /* True if there are relocations to text seg */ bool symbolic : 1; /* True if generated with "-Bsymbolic" */ bool deepbind : 1; /* True if loaded with RTLD_DEEPBIND" */ bool bind_now : 1; /* True if all relocations should be made first */ bool traced : 1; /* Already printed in ldd trace output */ bool jmpslots_done : 1; /* Already have relocated the jump slots */ bool init_done : 1; /* Already have added object to init list */ bool tls_static : 1; /* Already allocated offset for static TLS */ bool tls_dynamic : 1; /* A non-static DTV entry has been allocated */ bool phdr_alloc : 1; /* Phdr is allocated and needs to be freed. */ bool z_origin : 1; /* Process rpath and soname tokens */ bool z_nodelete : 1; /* Do not unload the object and dependencies */ bool z_noopen : 1; /* Do not load on dlopen */ bool z_loadfltr : 1; /* Immediately load filtees */ bool z_interpose : 1; /* Interpose all objects but main */ bool z_nodeflib : 1; /* Don't search default library path */ bool z_global : 1; /* Make the object global */ bool z_pie : 1; /* Object proclaimed itself PIE executable */ bool static_tls : 1; /* Needs static TLS allocation */ bool static_tls_copied : 1; /* Needs static TLS copying */ bool ref_nodel : 1; /* Refcount increased to prevent dlclose */ bool init_scanned: 1; /* Object is already on init list. */ bool on_fini_list: 1; /* Object is already on fini list. */ bool dag_inited : 1; /* Object has its DAG initialized. */ bool filtees_loaded : 1; /* Filtees loaded */ bool filtees_loading : 1; /* In process of filtees loading */ bool irelative : 1; /* Object has R_MACHDEP_IRELATIVE relocs */ bool irelative_nonplt : 1; /* Object has R_MACHDEP_IRELATIVE non-plt relocs */ bool gnu_ifunc : 1; /* Object has references to STT_GNU_IFUNC */ bool non_plt_gnu_ifunc : 1; /* Object has non-plt IFUNC references */ bool ifuncs_resolved : 1; /* Object ifuncs were already resolved */ bool crt_no_init : 1; /* Object' crt does not call _init/_fini */ bool valid_hash_sysv : 1; /* A valid System V hash hash tag is available */ bool valid_hash_gnu : 1; /* A valid GNU hash tag is available */ bool dlopened : 1; /* dlopen()-ed (vs. load statically) */ bool marker : 1; /* marker on the global obj list */ bool unholdfree : 1; /* unmap upon last unhold */ bool doomed : 1; /* Object cannot be referenced */ struct link_map linkmap; /* For GDB and dlinfo() */ Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ Objlist dagmembers; /* DAG has these members (%) */ dev_t dev; /* Object's filesystem's device */ ino_t ino; /* Object's inode number */ void *priv; /* Platform-dependent */ } Obj_Entry; #define RTLD_MAGIC 0xd550b87a #define RTLD_VERSION 1 TAILQ_HEAD(obj_entry_q, Struct_Obj_Entry); #define RTLD_STATIC_TLS_EXTRA 128 /* Flags to be passed into symlook_ family of functions. */ #define SYMLOOK_IN_PLT 0x01 /* Lookup for PLT symbol */ #define SYMLOOK_DLSYM 0x02 /* Return newest versioned symbol. Used by dlsym. */ #define SYMLOOK_EARLY 0x04 /* Symlook is done during initialization. */ #define SYMLOOK_IFUNC 0x08 /* Allow IFUNC processing in reloc_non_plt(). */ /* Flags for load_object(). */ #define RTLD_LO_NOLOAD 0x01 /* dlopen() specified RTLD_NOLOAD. */ #define RTLD_LO_DLOPEN 0x02 /* Load_object() called from dlopen(). */ #define RTLD_LO_TRACE 0x04 /* Only tracing. */ #define RTLD_LO_NODELETE 0x08 /* Loaded object cannot be closed. */ #define RTLD_LO_FILTEES 0x10 /* Loading filtee. */ #define RTLD_LO_EARLY 0x20 /* Do not call ctors, postpone it to the initialization during the image start. */ #define RTLD_LO_IGNSTLS 0x40 /* Do not allocate static TLS */ #define RTLD_LO_DEEPBIND 0x80 /* Force symbolic for this object */ /* * Symbol cache entry used during relocation to avoid multiple lookups * of the same symbol. */ typedef struct Struct_SymCache { const Elf_Sym *sym; /* Symbol table entry */ const Obj_Entry *obj; /* Shared object which defines it */ } SymCache; /* * This structure provides a reentrant way to keep a list of objects and * check which ones have already been processed in some way. */ typedef struct Struct_DoneList { const Obj_Entry **objs; /* Array of object pointers */ unsigned int num_alloc; /* Allocated size of the array */ unsigned int num_used; /* Number of array slots used */ } DoneList; struct Struct_RtldLockState { int lockstate; sigjmp_buf env; }; struct fill_search_info_args { int request; unsigned int flags; struct dl_serinfo *serinfo; struct dl_serpath *serpath; char *strspace; }; /* * The pack of arguments and results for the symbol lookup functions. */ typedef struct Struct_SymLook { const char *name; unsigned long hash; uint32_t hash_gnu; const Ver_Entry *ventry; int flags; const Obj_Entry *defobj_out; const Elf_Sym *sym_out; struct Struct_RtldLockState *lockstate; } SymLook; void _rtld_error(const char *, ...) __printflike(1, 2) __exported; void rtld_die(void) __dead2; const char *rtld_strerror(int); Obj_Entry *map_object(int, const char *, const struct stat *); void *xcalloc(size_t, size_t); void *xmalloc(size_t); char *xstrdup(const char *); void *xmalloc_aligned(size_t size, size_t align, size_t offset); extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; extern Elf_Sym sym_zero; /* For resolving undefined weak refs. */ extern bool ld_bind_not; extern bool ld_fast_sigblock; void dump_relocations(Obj_Entry *); void dump_obj_relocations(Obj_Entry *); void dump_Elf_Rel(Obj_Entry *, const Elf_Rel *, u_long); void dump_Elf_Rela(Obj_Entry *, const Elf_Rela *, u_long); /* * Function declarations. */ uintptr_t rtld_round_page(uintptr_t); uintptr_t rtld_trunc_page(uintptr_t); Elf32_Word elf_hash(const char *); const Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, const Obj_Entry **, int, SymCache *, struct Struct_RtldLockState *); void lockdflt_init(void); void digest_notes(Obj_Entry *, Elf_Addr, Elf_Addr); Obj_Entry *globallist_curr(const Obj_Entry *obj); Obj_Entry *globallist_next(const Obj_Entry *obj); void obj_free(Obj_Entry *); Obj_Entry *obj_new(void); Obj_Entry *obj_from_addr(const void *); void _rtld_bind_start(void); void *rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def); void symlook_init(SymLook *, const char *); int symlook_obj(SymLook *, const Obj_Entry *); void *tls_get_addr_common(uintptr_t **dtvp, int index, size_t offset); void *allocate_tls(Obj_Entry *, void *, size_t, size_t); void free_tls(void *, size_t, size_t); void *allocate_module_tls(int index); bool allocate_tls_offset(Obj_Entry *obj); void free_tls_offset(Obj_Entry *obj); const Ver_Entry *fetch_ventry(const Obj_Entry *obj, unsigned long); int convert_prot(int elfflags); bool check_elf_headers(const Elf_Ehdr *hdr, const char *path); /* * MD function declarations. */ int do_copy_relocations(Obj_Entry *); int reloc_non_plt(Obj_Entry *, Obj_Entry *, int flags, struct Struct_RtldLockState *); int reloc_plt(Obj_Entry *, int flags, struct Struct_RtldLockState *); int reloc_jmpslots(Obj_Entry *, int flags, struct Struct_RtldLockState *); int reloc_iresolve(Obj_Entry *, struct Struct_RtldLockState *); int reloc_iresolve_nonplt(Obj_Entry *, struct Struct_RtldLockState *); int reloc_gnu_ifunc(Obj_Entry *, int flags, struct Struct_RtldLockState *); void ifunc_init(Elf_Auxinfo[__min_size(AT_COUNT)]); void init_pltgot(Obj_Entry *); void allocate_initial_tls(Obj_Entry *); #endif /* } */