| 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 | * |
| 25 | * $FreeBSD: src/libexec/rtld-elf/rtld.h,v 1.15.2.6 2003/02/20 20:42:46 kan Exp $ |
| 26 | * $DragonFly: src/libexec/rtld-elf/rtld.h,v 1.11 2005/05/11 19:47:06 dillon Exp $ |
| 27 | */ |
| 28 | |
| 29 | #ifndef RTLD_H /* { */ |
| 30 | #define RTLD_H 1 |
| 31 | |
| 32 | #include <machine/elf.h> |
| 33 | #include <sys/types.h> |
| 34 | #include <sys/queue.h> |
| 35 | |
| 36 | #include <elf-hints.h> |
| 37 | #include <link.h> |
| 38 | #include <stddef.h> |
| 39 | |
| 40 | #include "rtld_machdep.h" |
| 41 | |
| 42 | #ifndef STANDARD_LIBRARY_PATH |
| 43 | #define STANDARD_LIBRARY_PATH "/usr/lib" |
| 44 | #endif |
| 45 | |
| 46 | #define NEW(type) ((type *) xmalloc(sizeof(type))) |
| 47 | #define CNEW(type) ((type *) xcalloc(sizeof(type))) |
| 48 | |
| 49 | /* We might as well do booleans like C++. */ |
| 50 | typedef unsigned char bool; |
| 51 | #define false 0 |
| 52 | #define true 1 |
| 53 | |
| 54 | extern size_t tls_last_offset; |
| 55 | extern size_t tls_last_size; |
| 56 | extern size_t tls_static_space; |
| 57 | extern int tls_dtv_generation; |
| 58 | extern int tls_max_index; |
| 59 | |
| 60 | extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; |
| 61 | |
| 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); |
| 75 | |
| 76 | /* Lists of shared object dependencies */ |
| 77 | typedef struct Struct_Needed_Entry { |
| 78 | struct Struct_Needed_Entry *next; |
| 79 | struct Struct_Obj_Entry *obj; |
| 80 | unsigned long name; /* Offset of name in string table */ |
| 81 | } Needed_Entry; |
| 82 | |
| 83 | /* Lock object */ |
| 84 | typedef struct Struct_LockInfo { |
| 85 | void *context; /* Client context for creating locks */ |
| 86 | void *thelock; /* The one big lock */ |
| 87 | /* Debugging aids. */ |
| 88 | volatile int rcount; /* Number of readers holding lock */ |
| 89 | volatile int wcount; /* Number of writers holding lock */ |
| 90 | /* Methods */ |
| 91 | void *(*lock_create)(void *context); |
| 92 | void (*rlock_acquire)(void *lock); |
| 93 | void (*wlock_acquire)(void *lock); |
| 94 | void (*rlock_release)(void *lock); |
| 95 | void (*wlock_release)(void *lock); |
| 96 | void (*lock_destroy)(void *lock); |
| 97 | void (*context_destroy)(void *context); |
| 98 | } LockInfo; |
| 99 | |
| 100 | /* |
| 101 | * Shared object descriptor. |
| 102 | * |
| 103 | * Items marked with "(%)" are dynamically allocated, and must be freed |
| 104 | * when the structure is destroyed. |
| 105 | * |
| 106 | * CAUTION: It appears that the JDK port peeks into these structures. |
| 107 | * It looks at "next" and "mapbase" at least. Don't add new members |
| 108 | * near the front, until this can be straightened out. |
| 109 | */ |
| 110 | typedef struct Struct_Obj_Entry { |
| 111 | /* |
| 112 | * These two items have to be set right for compatibility with the |
| 113 | * original ElfKit crt1.o. |
| 114 | */ |
| 115 | Elf_Word magic; /* Magic number (sanity check) */ |
| 116 | Elf_Word version; /* Version number of struct format */ |
| 117 | |
| 118 | struct Struct_Obj_Entry *next; |
| 119 | char *path; /* Pathname of underlying file (%) */ |
| 120 | char *origin_path; /* Directory path of origin file */ |
| 121 | int refcount; |
| 122 | int dl_refcount; /* Number of times loaded by dlopen */ |
| 123 | |
| 124 | /* These items are computed by map_object() or by digest_phdr(). */ |
| 125 | caddr_t mapbase; /* Base address of mapped region */ |
| 126 | size_t mapsize; /* Size of mapped region in bytes */ |
| 127 | size_t textsize; /* Size of text segment in bytes */ |
| 128 | Elf_Addr vaddrbase; /* Base address in shared object file */ |
| 129 | caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ |
| 130 | const Elf_Dyn *dynamic; /* Dynamic section */ |
| 131 | caddr_t entry; /* Entry point */ |
| 132 | const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ |
| 133 | size_t phsize; /* Size of program header in bytes */ |
| 134 | const char *interp; /* Pathname of the interpreter, if any */ |
| 135 | |
| 136 | /* TLS information */ |
| 137 | int tlsindex; /* Index in DTV for this module */ |
| 138 | void *tlsinit; /* Base address of TLS init block */ |
| 139 | size_t tlsinitsize; /* Size of TLS init block for this module */ |
| 140 | size_t tlssize; /* Size of TLS block for this module */ |
| 141 | size_t tlsoffset; /* Offset of static TLS block for this module */ |
| 142 | size_t tlsalign; /* Alignment of static TLS block */ |
| 143 | |
| 144 | /* Items from the dynamic section. */ |
| 145 | Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ |
| 146 | const Elf_Rel *rel; /* Relocation entries */ |
| 147 | unsigned long relsize; /* Size in bytes of relocation info */ |
| 148 | const Elf_Rela *rela; /* Relocation entries with addend */ |
| 149 | unsigned long relasize; /* Size in bytes of addend relocation info */ |
| 150 | const Elf_Rel *pltrel; /* PLT relocation entries */ |
| 151 | unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ |
| 152 | const Elf_Rela *pltrela; /* PLT relocation entries with addend */ |
| 153 | unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ |
| 154 | const Elf_Sym *symtab; /* Symbol table */ |
| 155 | const char *strtab; /* String table */ |
| 156 | unsigned long strsize; /* Size in bytes of string table */ |
| 157 | |
| 158 | const Elf_Addr *buckets; /* Hash table buckets array */ |
| 159 | unsigned long nbuckets; /* Number of buckets */ |
| 160 | const Elf_Addr *chains; /* Hash table chain array */ |
| 161 | unsigned long nchains; /* Number of chains */ |
| 162 | |
| 163 | const char *rpath; /* Search path specified in object */ |
| 164 | Needed_Entry *needed; /* Shared objects needed by this one (%) */ |
| 165 | |
| 166 | InitFunc init; /* Initialization function to call */ |
| 167 | InitFunc fini; /* Termination function to call */ |
| 168 | |
| 169 | bool mainprog; /* True if this is the main program */ |
| 170 | bool rtld; /* True if this is the dynamic linker */ |
| 171 | bool textrel; /* True if there are relocations to text seg */ |
| 172 | bool symbolic; /* True if generated with "-Bsymbolic" */ |
| 173 | bool bind_now; /* True if all relocations should be made first */ |
| 174 | bool traced; /* Already printed in ldd trace output */ |
| 175 | bool jmpslots_done; /* Already have relocated the jump slots */ |
| 176 | bool init_done; /* Already have added object to init list */ |
| 177 | bool tls_done; /* Already allocated offset for static TLS */ |
| 178 | |
| 179 | struct link_map linkmap; /* for GDB and dlinfo() */ |
| 180 | Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ |
| 181 | Objlist dagmembers; /* DAG has these members (%) */ |
| 182 | dev_t dev; /* Object's filesystem's device */ |
| 183 | ino_t ino; /* Object's inode number */ |
| 184 | } Obj_Entry; |
| 185 | |
| 186 | #define RTLD_MAGIC 0xd550b87a |
| 187 | #define RTLD_VERSION 1 |
| 188 | |
| 189 | /* |
| 190 | * Symbol cache entry used during relocation to avoid multiple lookups |
| 191 | * of the same symbol. |
| 192 | */ |
| 193 | typedef struct Struct_SymCache { |
| 194 | const Elf_Sym *sym; /* Symbol table entry */ |
| 195 | const Obj_Entry *obj; /* Shared object which defines it */ |
| 196 | } SymCache; |
| 197 | |
| 198 | void _rtld_error(const char *, ...) __printflike(1, 2); |
| 199 | Obj_Entry *map_object(int, const char *, const struct stat *); |
| 200 | void *xcalloc(size_t); |
| 201 | void *xmalloc(size_t); |
| 202 | void *xrealloc(void *, size_t); |
| 203 | char *xstrdup(const char *); |
| 204 | |
| 205 | void dump_relocations(Obj_Entry *); |
| 206 | void dump_obj_relocations(Obj_Entry *); |
| 207 | void dump_Elf_Rel(Obj_Entry *, const Elf_Rel *, u_long); |
| 208 | void dump_Elf_Rela(Obj_Entry *, const Elf_Rela *, u_long); |
| 209 | |
| 210 | /* |
| 211 | * Function declarations. |
| 212 | */ |
| 213 | const char *basename(const char *); |
| 214 | int do_copy_relocations(Obj_Entry *); |
| 215 | unsigned long elf_hash(const char *); |
| 216 | const Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, |
| 217 | const Obj_Entry **, bool, SymCache *); |
| 218 | void init_pltgot(Obj_Entry *); |
| 219 | void lockdflt_init(LockInfo *); |
| 220 | void obj_free(Obj_Entry *); |
| 221 | Obj_Entry *obj_new(void); |
| 222 | int reloc_non_plt(Obj_Entry *, Obj_Entry *); |
| 223 | int reloc_plt(Obj_Entry *); |
| 224 | int reloc_jmpslots(Obj_Entry *); |
| 225 | void _rtld_bind_start(void); |
| 226 | const Elf_Sym *symlook_obj(const char *, unsigned long, const Obj_Entry *, |
| 227 | bool); |
| 228 | |
| 229 | void *tls_get_addr_common(void **, int, size_t); |
| 230 | struct tls_tcb *allocate_tls(Obj_Entry *); |
| 231 | void free_tls(struct tls_tcb *); |
| 232 | void *allocate_module_tls(int); |
| 233 | bool allocate_tls_offset(Obj_Entry *); |
| 234 | void free_tls_offset(Obj_Entry *); |
| 235 | void allocate_initial_tls(Obj_Entry *); |
| 236 | #endif /* } */ |