crt0-common.c revision 1.16
1 /* $NetBSD: crt0-common.c,v 1.16 2018/03/29 13:23:39 joerg Exp $ */ 2 3 /* 4 * Copyright (c) 1998 Christos Zoulas 5 * Copyright (c) 1995 Christopher G. Demetriou 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed for the 19 * NetBSD Project. See http://www.NetBSD.org/ for 20 * information about NetBSD. 21 * 4. The name of the author may not be used to endorse or promote products 22 * derived from this software without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 * 35 * <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>> 36 */ 37 38 #include <sys/cdefs.h> 39 __RCSID("$NetBSD: crt0-common.c,v 1.16 2018/03/29 13:23:39 joerg Exp $"); 40 41 #include <sys/types.h> 42 #include <sys/exec.h> 43 #include <sys/syscall.h> 44 #include <machine/profile.h> 45 #include <stdlib.h> 46 #include <unistd.h> 47 48 #include "rtld.h" 49 50 extern int main(int, char **, char **); 51 52 #ifndef HAVE_INITFINI_ARRAY 53 extern void _init(void); 54 extern void _fini(void); 55 #endif 56 extern void _libc_init(void); 57 58 /* 59 * Arrange for _DYNAMIC to be weak and undefined (and therefore to show up 60 * as being at address zero, unless something else defines it). That way, 61 * if we happen to be compiling without -static but with without any 62 * shared libs present, things will still work. 63 */ 64 65 __weakref_visible int rtld_DYNAMIC __weak_reference(_DYNAMIC); 66 67 #ifdef MCRT0 68 extern void monstartup(u_long, u_long); 69 extern void _mcleanup(void); 70 extern unsigned char __etext, __eprol; 71 #endif /* MCRT0 */ 72 73 char **environ; 74 struct ps_strings *__ps_strings = 0; 75 76 static char empty_string[] = ""; 77 char *__progname = empty_string; 78 79 __dead __dso_hidden void ___start(void (*)(void), const Obj_Entry *, 80 struct ps_strings *); 81 82 #define write(fd, s, n) __syscall(SYS_write, (fd), (s), (n)) 83 84 #define _FATAL(str) \ 85 do { \ 86 write(2, str, sizeof(str)-1); \ 87 _exit(1); \ 88 } while (0) 89 90 #ifdef HAVE_INITFINI_ARRAY 91 /* 92 * If we are using INIT_ARRAY/FINI_ARRAY and we are linked statically, 93 * we have to process these instead of relying on RTLD to do it for us. 94 * 95 * Since we don't need .init or .fini sections, just code them in C 96 * to make life easier. 97 */ 98 extern const fptr_t __preinit_array_start[] __dso_hidden; 99 extern const fptr_t __preinit_array_end[] __dso_hidden __weak; 100 extern const fptr_t __init_array_start[] __dso_hidden; 101 extern const fptr_t __init_array_end[] __dso_hidden __weak; 102 extern const fptr_t __fini_array_start[] __dso_hidden; 103 extern const fptr_t __fini_array_end[] __dso_hidden __weak; 104 105 static inline void 106 _preinit(void) 107 { 108 for (const fptr_t *f = __preinit_array_start; f < __preinit_array_end; f++) { 109 (*f)(); 110 } 111 } 112 113 static inline void 114 _init(void) 115 { 116 for (const fptr_t *f = __init_array_start; f < __init_array_end; f++) { 117 (*f)(); 118 } 119 } 120 121 static void 122 _fini(void) 123 { 124 for (const fptr_t *f = __fini_array_start; f < __fini_array_end; f++) { 125 (*f)(); 126 } 127 } 128 #endif /* HAVE_INITFINI_ARRAY */ 129 130 #if defined(__x86_64__) || defined(__powerpc__) || defined(__sparc__) 131 #define HAS_IPLTA 132 static void fix_iplta(void) __noinline; 133 #elif defined(__i386__) || defined(__arm__) 134 #define HAS_IPLT 135 static void fix_iplt(void) __noinline; 136 #endif 137 138 139 #ifdef HAS_IPLTA 140 #include <stdio.h> 141 extern const Elf_Rela __rela_iplt_start[] __dso_hidden __weak; 142 extern const Elf_Rela __rela_iplt_end[] __dso_hidden __weak; 143 #ifdef __sparc__ 144 #define IFUNC_RELOCATION R_TYPE(JMP_IREL) 145 #include <machine/elf_support.h> 146 #define write_plt(where, value) sparc_write_branch((void *)where, (void *)value) 147 #else 148 #define IFUNC_RELOCATION R_TYPE(IRELATIVE) 149 #define write_plt(where, value) *where = value 150 #endif 151 152 static void 153 fix_iplta(void) 154 { 155 const Elf_Rela *rela, *relalim; 156 uintptr_t relocbase = 0; 157 Elf_Addr *where, target; 158 159 rela = __rela_iplt_start; 160 relalim = __rela_iplt_end; 161 for (; rela < relalim; ++rela) { 162 if (ELF_R_TYPE(rela->r_info) != IFUNC_RELOCATION) 163 abort(); 164 where = (Elf_Addr *)(relocbase + rela->r_offset); 165 target = (Elf_Addr)(relocbase + rela->r_addend); 166 target = ((Elf_Addr(*)(void))target)(); 167 write_plt(where, target); 168 } 169 } 170 #endif 171 #ifdef HAS_IPLT 172 extern const Elf_Rel __rel_iplt_start[] __dso_hidden __weak; 173 extern const Elf_Rel __rel_iplt_end[] __dso_hidden __weak; 174 #define IFUNC_RELOCATION R_TYPE(IRELATIVE) 175 176 static void 177 fix_iplt(void) 178 { 179 const Elf_Rel *rel, *rellim; 180 uintptr_t relocbase = 0; 181 Elf_Addr *where, target; 182 183 rel = __rel_iplt_start; 184 rellim = __rel_iplt_end; 185 for (; rel < rellim; ++rel) { 186 if (ELF_R_TYPE(rel->r_info) != IFUNC_RELOCATION) 187 abort(); 188 where = (Elf_Addr *)(relocbase + rel->r_offset); 189 target = ((Elf_Addr(*)(void))*where)(); 190 *where = target; 191 } 192 } 193 #endif 194 195 void 196 ___start(void (*cleanup)(void), /* from shared loader */ 197 const Obj_Entry *obj, /* from shared loader */ 198 struct ps_strings *ps_strings) 199 { 200 201 if (ps_strings == NULL) 202 _FATAL("ps_strings missing\n"); 203 __ps_strings = ps_strings; 204 205 environ = ps_strings->ps_envstr; 206 207 if (ps_strings->ps_argvstr[0] != NULL) { 208 char *c; 209 __progname = ps_strings->ps_argvstr[0]; 210 for (c = ps_strings->ps_argvstr[0]; *c; ++c) { 211 if (*c == '/') 212 __progname = c + 1; 213 } 214 } else { 215 __progname = empty_string; 216 } 217 218 if (&rtld_DYNAMIC != NULL) { 219 if (obj == NULL) 220 _FATAL("NULL Obj_Entry pointer in GOT\n"); 221 if (obj->magic != RTLD_MAGIC) 222 _FATAL("Corrupt Obj_Entry pointer in GOT\n"); 223 if (obj->version != RTLD_VERSION) 224 _FATAL("Dynamic linker version mismatch\n"); 225 atexit(cleanup); 226 } 227 228 _libc_init(); 229 230 if (&rtld_DYNAMIC == NULL) { 231 #ifdef HAS_IPLTA 232 fix_iplta(); 233 #endif 234 #ifdef HAS_IPLT 235 fix_iplt(); 236 #endif 237 } 238 239 #ifdef HAVE_INITFINI_ARRAY 240 _preinit(); 241 #endif 242 243 #ifdef MCRT0 244 atexit(_mcleanup); 245 monstartup((u_long)&__eprol, (u_long)&__etext); 246 #endif 247 248 atexit(_fini); 249 _init(); 250 251 exit(main(ps_strings->ps_nargvstr, ps_strings->ps_argvstr, environ)); 252 } 253
Indexes created Mon Sep 29 21:09:56 GMT 2025