| Commit | Line | Data |
|---|---|---|
| 984263bc MD |
1 | /*- |
| 2 | * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * Redistribution and use in source and binary forms, with or without | |
| 6 | * modification, are permitted provided that the following conditions | |
| 7 | * are met: | |
| 8 | * 1. Redistributions of source code must retain the above copyright | |
| 9 | * notice, this list of conditions and the following disclaimer. | |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright | |
| 11 | * notice, this list of conditions and the following disclaimer in the | |
| 12 | * documentation and/or other materials provided with the distribution. | |
| 13 | * | |
| 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
| 15 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
| 16 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
| 17 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
| 18 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
| 19 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| 20 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
| 21 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 22 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
| 23 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 24 | * | |
| f4f4bfd5 | 25 | * $FreeBSD$ |
| 984263bc MD |
26 | */ |
| 27 | ||
| 28 | #ifndef RTLD_H /* { */ | |
| 29 | #define RTLD_H 1 | |
| 30 | ||
| 31 | #include <machine/elf.h> | |
| 32 | #include <sys/types.h> | |
| 33 | #include <sys/queue.h> | |
| 34 | ||
| 35 | #include <elf-hints.h> | |
| 36 | #include <link.h> | |
| abfcd5b1 | 37 | #include <stdarg.h> |
| fcf53d9b | 38 | #include <setjmp.h> |
| 984263bc MD |
39 | #include <stddef.h> |
| 40 | ||
| fcf53d9b | 41 | #include "rtld_lock.h" |
| 984263bc MD |
42 | #include "rtld_machdep.h" |
| 43 | ||
| 44 | #ifndef STANDARD_LIBRARY_PATH | |
| 45 | #define STANDARD_LIBRARY_PATH "/usr/lib" | |
| 46 | #endif | |
| 47 | ||
| 48 | #define NEW(type) ((type *) xmalloc(sizeof(type))) | |
| 49 | #define CNEW(type) ((type *) xcalloc(sizeof(type))) | |
| 50 | ||
| 51 | /* We might as well do booleans like C++. */ | |
| 52 | typedef unsigned char bool; | |
| 53 | #define false 0 | |
| 54 | #define true 1 | |
| 55 | ||
| 55b88cae DX |
56 | extern size_t tls_last_offset; |
| 57 | extern size_t tls_last_size; | |
| 58 | extern size_t tls_static_space; | |
| 59 | extern int tls_dtv_generation; | |
| 60 | extern int tls_max_index; | |
| 61 | ||
| 984263bc MD |
62 | struct stat; |
| 63 | struct Struct_Obj_Entry; | |
| 64 | ||
| 65 | /* Lists of shared objects */ | |
| 66 | typedef struct Struct_Objlist_Entry { | |
| 67 | STAILQ_ENTRY(Struct_Objlist_Entry) link; | |
| 68 | struct Struct_Obj_Entry *obj; | |
| 69 | } Objlist_Entry; | |
| 70 | ||
| 71 | typedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; | |
| 72 | ||
| 73 | /* Types of init and fini functions */ | |
| 74 | typedef void (*InitFunc)(void); | |
| b28bf640 | 75 | typedef void (*InitArrayFunc)(int, char **, char **); |
| 984263bc MD |
76 | |
| 77 | /* Lists of shared object dependencies */ | |
| 78 | typedef struct Struct_Needed_Entry { | |
| 79 | struct Struct_Needed_Entry *next; | |
| 80 | struct Struct_Obj_Entry *obj; | |
| 81 | unsigned long name; /* Offset of name in string table */ | |
| 82 | } Needed_Entry; | |
| 83 | ||
| fcf53d9b JM |
84 | typedef struct Struct_Name_Entry { |
| 85 | STAILQ_ENTRY(Struct_Name_Entry) link; | |
| 86 | char name[1]; | |
| 87 | } Name_Entry; | |
| 88 | ||
| 984263bc MD |
89 | /* Lock object */ |
| 90 | typedef struct Struct_LockInfo { | |
| 91 | void *context; /* Client context for creating locks */ | |
| 92 | void *thelock; /* The one big lock */ | |
| 93 | /* Debugging aids. */ | |
| 94 | volatile int rcount; /* Number of readers holding lock */ | |
| 95 | volatile int wcount; /* Number of writers holding lock */ | |
| 96 | /* Methods */ | |
| 97 | void *(*lock_create)(void *context); | |
| 98 | void (*rlock_acquire)(void *lock); | |
| 99 | void (*wlock_acquire)(void *lock); | |
| 100 | void (*rlock_release)(void *lock); | |
| 101 | void (*wlock_release)(void *lock); | |
| 102 | void (*lock_destroy)(void *lock); | |
| 103 | void (*context_destroy)(void *context); | |
| 104 | } LockInfo; | |
| 105 | ||
| fcf53d9b JM |
106 | typedef struct Struct_Ver_Entry { |
| 107 | Elf_Word hash; | |
| 108 | unsigned int flags; | |
| 109 | const char *name; | |
| 110 | const char *file; | |
| 111 | } Ver_Entry; | |
| 112 | ||
| 113 | #define VER_INFO_HIDDEN 0x01 | |
| 114 | ||
| 984263bc MD |
115 | /* |
| 116 | * Shared object descriptor. | |
| 117 | * | |
| 118 | * Items marked with "(%)" are dynamically allocated, and must be freed | |
| 119 | * when the structure is destroyed. | |
| 120 | * | |
| 121 | * CAUTION: It appears that the JDK port peeks into these structures. | |
| 122 | * It looks at "next" and "mapbase" at least. Don't add new members | |
| 123 | * near the front, until this can be straightened out. | |
| 124 | */ | |
| 125 | typedef struct Struct_Obj_Entry { | |
| 126 | /* | |
| 127 | * These two items have to be set right for compatibility with the | |
| 128 | * original ElfKit crt1.o. | |
| 129 | */ | |
| 4648abf3 MD |
130 | Elf_Size magic; /* Magic number (sanity check) */ |
| 131 | Elf_Size version; /* Version number of struct format */ | |
| 984263bc MD |
132 | |
| 133 | struct Struct_Obj_Entry *next; | |
| 134 | char *path; /* Pathname of underlying file (%) */ | |
| 167f7029 | 135 | char *origin_path; /* Directory path of origin file */ |
| 984263bc MD |
136 | int refcount; |
| 137 | int dl_refcount; /* Number of times loaded by dlopen */ | |
| 138 | ||
| 139 | /* These items are computed by map_object() or by digest_phdr(). */ | |
| 140 | caddr_t mapbase; /* Base address of mapped region */ | |
| 141 | size_t mapsize; /* Size of mapped region in bytes */ | |
| 142 | size_t textsize; /* Size of text segment in bytes */ | |
| 143 | Elf_Addr vaddrbase; /* Base address in shared object file */ | |
| 144 | caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ | |
| 145 | const Elf_Dyn *dynamic; /* Dynamic section */ | |
| 146 | caddr_t entry; /* Entry point */ | |
| 147 | const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ | |
| 148 | size_t phsize; /* Size of program header in bytes */ | |
| 149 | const char *interp; /* Pathname of the interpreter, if any */ | |
| 007f494e JM |
150 | caddr_t relro_page; /* Address of first page of read-only data */ |
| 151 | size_t relro_size; /* Size of relro page(s) in bytes */ | |
| e9de6dcc | 152 | Elf_Word stack_flags; |
| 984263bc | 153 | |
| 55b88cae DX |
154 | /* TLS information */ |
| 155 | int tlsindex; /* Index in DTV for this module */ | |
| 156 | void *tlsinit; /* Base address of TLS init block */ | |
| 157 | size_t tlsinitsize; /* Size of TLS init block for this module */ | |
| 158 | size_t tlssize; /* Size of TLS block for this module */ | |
| 159 | size_t tlsoffset; /* Offset of static TLS block for this module */ | |
| 160 | size_t tlsalign; /* Alignment of static TLS block */ | |
| 161 | ||
| 984263bc MD |
162 | /* Items from the dynamic section. */ |
| 163 | Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ | |
| 164 | const Elf_Rel *rel; /* Relocation entries */ | |
| 165 | unsigned long relsize; /* Size in bytes of relocation info */ | |
| 166 | const Elf_Rela *rela; /* Relocation entries with addend */ | |
| 167 | unsigned long relasize; /* Size in bytes of addend relocation info */ | |
| 168 | const Elf_Rel *pltrel; /* PLT relocation entries */ | |
| 169 | unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ | |
| 170 | const Elf_Rela *pltrela; /* PLT relocation entries with addend */ | |
| 171 | unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ | |
| 172 | const Elf_Sym *symtab; /* Symbol table */ | |
| 173 | const char *strtab; /* String table */ | |
| 174 | unsigned long strsize; /* Size in bytes of string table */ | |
| 175 | ||
| fcf53d9b JM |
176 | const Elf_Verneed *verneed; /* Required versions. */ |
| 177 | Elf_Word verneednum; /* Number of entries in verneed table */ | |
| 178 | const Elf_Verdef *verdef; /* Provided versions. */ | |
| 179 | Elf_Word verdefnum; /* Number of entries in verdef table */ | |
| 180 | const Elf_Versym *versyms; /* Symbol versions table */ | |
| 181 | ||
| d697cc44 | 182 | const Elf_Hashelt *buckets; /* Hash table buckets array */ |
| 984263bc | 183 | unsigned long nbuckets; /* Number of buckets */ |
| d697cc44 | 184 | const Elf_Hashelt *chains; /* Hash table chain array */ |
| 984263bc MD |
185 | unsigned long nchains; /* Number of chains */ |
| 186 | ||
| fcf53d9b | 187 | char *rpath; /* Search path specified in object */ |
| 984263bc | 188 | Needed_Entry *needed; /* Shared objects needed by this one (%) */ |
| 35b2b265 JM |
189 | Needed_Entry *needed_filtees; |
| 190 | Needed_Entry *needed_aux_filtees; | |
| 984263bc | 191 | |
| fcf53d9b JM |
192 | STAILQ_HEAD(, Struct_Name_Entry) names; /* List of names for this object we |
| 193 | know about. */ | |
| 194 | Ver_Entry *vertab; /* Versions required /defined by this object */ | |
| 195 | int vernum; /* Number of entries in vertab */ | |
| 196 | ||
| 197 | Elf_Addr init; /* Initialization function to call */ | |
| 198 | Elf_Addr fini; /* Termination function to call */ | |
| b28bf640 JM |
199 | Elf_Addr preinit_array; /* Pre-initialization array of functions */ |
| 200 | Elf_Addr init_array; /* Initialization array of functions */ | |
| 201 | Elf_Addr fini_array; /* Termination array of functions */ | |
| 202 | int preinit_array_num; /* Number of entries in preinit_array */ | |
| 203 | int init_array_num; /* Number of entries in init_array */ | |
| 204 | int fini_array_num; /* Number of entries in fini_array */ | |
| fcf53d9b JM |
205 | |
| 206 | bool mainprog : 1; /* True if this is the main program */ | |
| 207 | bool rtld : 1; /* True if this is the dynamic linker */ | |
| 208 | bool textrel : 1; /* True if there are relocations to text seg */ | |
| 209 | bool symbolic : 1; /* True if generated with "-Bsymbolic" */ | |
| 210 | bool bind_now : 1; /* True if all relocations should be made first */ | |
| 211 | bool traced : 1; /* Already printed in ldd trace output */ | |
| 212 | bool jmpslots_done : 1; /* Already have relocated the jump slots */ | |
| 213 | bool init_done : 1; /* Already have added object to init list */ | |
| 214 | bool tls_done : 1; /* Already allocated offset for static TLS */ | |
| 215 | bool phdr_alloc : 1; /* Phdr is allocated and needs to be freed. */ | |
| 216 | bool z_origin : 1; /* Process rpath and soname tokens */ | |
| 217 | bool z_nodelete : 1; /* Do not unload the object and dependencies */ | |
| 218 | bool z_noopen : 1; /* Do not load on dlopen */ | |
| 35b2b265 | 219 | bool z_loadfltr : 1; /* Immediately load filtees */ |
| fcf53d9b JM |
220 | bool ref_nodel : 1; /* Refcount increased to prevent dlclose */ |
| 221 | bool init_scanned: 1; /* Object is already on init list. */ | |
| 222 | bool on_fini_list: 1; /* Object is already on fini list. */ | |
| 223 | bool dag_inited : 1; /* Object has its DAG initialized. */ | |
| 35b2b265 | 224 | bool filtees_loaded : 1; /* Filtees loaded */ |
| 0e63a289 JM |
225 | bool irelative : 1; /* Object has R_MACHDEP_IRELATIVE relocs */ |
| 226 | bool gnu_ifunc : 1; /* Object has references to STT_GNU_IFUNC */ | |
| fcf53d9b JM |
227 | |
| 228 | struct link_map linkmap; /* For GDB and dlinfo() */ | |
| 984263bc MD |
229 | Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ |
| 230 | Objlist dagmembers; /* DAG has these members (%) */ | |
| 231 | dev_t dev; /* Object's filesystem's device */ | |
| 232 | ino_t ino; /* Object's inode number */ | |
| 30aefd4f | 233 | void *priv; /* Platform-dependent */ |
| 984263bc MD |
234 | } Obj_Entry; |
| 235 | ||
| 236 | #define RTLD_MAGIC 0xd550b87a | |
| 237 | #define RTLD_VERSION 1 | |
| 238 | ||
| 35b2b265 JM |
239 | #define RTLD_FUNCTRACE "_rtld_functrace" |
| 240 | ||
| fcf53d9b JM |
241 | /* Flags to be passed into symlook_ family of functions. */ |
| 242 | #define SYMLOOK_IN_PLT 0x01 /* Lookup for PLT symbol */ | |
| 30aefd4f | 243 | #define SYMLOOK_DLSYM 0x02 /* Return newest versioned symbol. Used by |
| fcf53d9b JM |
244 | dlsym. */ |
| 245 | ||
| 246 | /* Flags for load_object(). */ | |
| 247 | #define RTLD_LO_NOLOAD 0x01 /* dlopen() specified RTLD_NOLOAD. */ | |
| 248 | #define RTLD_LO_DLOPEN 0x02 /* Load_object() called from dlopen(). */ | |
| 35b2b265 JM |
249 | #define RTLD_LO_TRACE 0x04 /* Only tracing. */ |
| 250 | #define RTLD_LO_NODELETE 0x08 /* Loaded object cannot be closed. */ | |
| 251 | #define RTLD_LO_FILTEES 0x10 /* Loading filtee. */ | |
| fcf53d9b | 252 | |
| 984263bc MD |
253 | /* |
| 254 | * Symbol cache entry used during relocation to avoid multiple lookups | |
| 255 | * of the same symbol. | |
| 256 | */ | |
| 257 | typedef struct Struct_SymCache { | |
| 258 | const Elf_Sym *sym; /* Symbol table entry */ | |
| 259 | const Obj_Entry *obj; /* Shared object which defines it */ | |
| 260 | } SymCache; | |
| 261 | ||
| 35b2b265 JM |
262 | /* |
| 263 | * This structure provides a reentrant way to keep a list of objects and | |
| 264 | * check which ones have already been processed in some way. | |
| 265 | */ | |
| 266 | typedef struct Struct_DoneList { | |
| 267 | const Obj_Entry **objs; /* Array of object pointers */ | |
| 268 | unsigned int num_alloc; /* Allocated size of the array */ | |
| 269 | unsigned int num_used; /* Number of array slots used */ | |
| 270 | } DoneList; | |
| 271 | ||
| fcf53d9b JM |
272 | struct Struct_RtldLockState { |
| 273 | int lockstate; | |
| 274 | sigjmp_buf env; | |
| 275 | }; | |
| 276 | ||
| 35b2b265 JM |
277 | /* |
| 278 | * The pack of arguments and results for the symbol lookup functions. | |
| 279 | */ | |
| 280 | typedef struct Struct_SymLook { | |
| 281 | const char *name; | |
| 282 | unsigned long hash; | |
| 283 | const Ver_Entry *ventry; | |
| 284 | int flags; | |
| 285 | const Obj_Entry *defobj_out; | |
| 286 | const Elf_Sym *sym_out; | |
| 287 | struct Struct_RtldLockState *lockstate; | |
| 288 | } SymLook; | |
| 289 | ||
| fcf53d9b JM |
290 | void _rtld_error(const char *, ...) __printflike(1, 2); |
| 291 | Obj_Entry *map_object(int, const char *, const struct stat *); | |
| 292 | void *xcalloc(size_t); | |
| 293 | void *xmalloc(size_t); | |
| 294 | char *xstrdup(const char *); | |
| 4648abf3 MD |
295 | extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; |
| 296 | ||
| fcf53d9b JM |
297 | void dump_relocations(Obj_Entry *); |
| 298 | void dump_obj_relocations(Obj_Entry *); | |
| 299 | void dump_Elf_Rel(Obj_Entry *, const Elf_Rel *, u_long); | |
| 300 | void dump_Elf_Rela(Obj_Entry *, const Elf_Rela *, u_long); | |
| 301 | ||
| 984263bc MD |
302 | /* |
| 303 | * Function declarations. | |
| 304 | */ | |
| fcf53d9b JM |
305 | const char *basename(const char *); |
| 306 | unsigned long elf_hash(const char *); | |
| 307 | const Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, | |
| 35b2b265 | 308 | const Obj_Entry **, int, SymCache *, struct Struct_RtldLockState *); |
| fcf53d9b JM |
309 | void init_pltgot(Obj_Entry *); |
| 310 | void lockdflt_init(void); | |
| 311 | void obj_free(Obj_Entry *); | |
| 312 | Obj_Entry *obj_new(void); | |
| 313 | void _rtld_bind_start(void); | |
| 0e63a289 | 314 | void *rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def); |
| 35b2b265 JM |
315 | void symlook_init(SymLook *, const char *); |
| 316 | int symlook_obj(SymLook *, const Obj_Entry *); | |
| fcf53d9b | 317 | void *tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset); |
| a1eee96a | 318 | struct tls_tcb *allocate_tls(Obj_Entry *); |
| fcf53d9b JM |
319 | void free_tls(struct tls_tcb *); |
| 320 | void *allocate_module_tls(int index); | |
| 321 | bool allocate_tls_offset(Obj_Entry *obj); | |
| 322 | void free_tls_offset(Obj_Entry *obj); | |
| 323 | const Ver_Entry *fetch_ventry(const Obj_Entry *obj, unsigned long); | |
| 324 | ||
| 325 | /* | |
| 326 | * MD function declarations. | |
| 327 | */ | |
| 328 | int do_copy_relocations(Obj_Entry *); | |
| 35b2b265 | 329 | int reloc_non_plt(Obj_Entry *, Obj_Entry *, struct Struct_RtldLockState *); |
| fcf53d9b | 330 | int reloc_plt(Obj_Entry *); |
| 35b2b265 | 331 | int reloc_jmpslots(Obj_Entry *, struct Struct_RtldLockState *); |
| 0e63a289 JM |
332 | int reloc_iresolve(Obj_Entry *, struct Struct_RtldLockState *); |
| 333 | int reloc_gnu_ifunc(Obj_Entry *, struct Struct_RtldLockState *); | |
| fcf53d9b | 334 | void allocate_initial_tls(Obj_Entry *); |
| 139b8f34 | 335 | |
| 984263bc | 336 | #endif /* } */ |