crt0-common.c revision 1.14.14.1
1 /* $NetBSD: crt0-common.c,v 1.14.14.1 2018/03/15 09:12:01 pgoyette 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 1.14.14.1 2018/03/15 09:12:01 pgoyette 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; 143 144 static void 145 fix_iplta(void) 146 { 147 const Elf_Rela *rela, *relalim; 148 uintptr_t relocbase = 0; 149 Elf_Addr *where, target; 150 151 rela = __rela_iplt_start; 152 relalim = __rela_iplt_end; 153 #if DEBUG 154 printf("%p - %p\n", rela, relalim); 155 #endif 156 for (; rela < relalim; ++rela) { 157 if (ELF_R_TYPE(rela->r_info) != R_TYPE(IRELATIVE)) 158 abort(); 159 where = (Elf_Addr *)(relocbase + rela->r_offset); 160 #if DEBUG 161 printf("location: %p\n", where); 162 #endif 163 target = (Elf_Addr)(relocbase + rela->r_addend); 164 #if DEBUG 165 printf("target: %p\n", (void *)target); 166 #endif 167 target = ((Elf_Addr(*)(void))target)(); 168 #if DEBUG 169 printf("...resolves to: %p\n", (void *)target); 170 #endif 171 *where = target; 172 } 173 } 174 #endif 175 #ifdef HAS_IPLT 176 extern const Elf_Rel __rel_iplt_start[] __dso_hidden __weak; 177 extern const Elf_Rel __rel_iplt_end[] __dso_hidden __weak; 178 179 static void 180 fix_iplt(void) 181 { 182 const Elf_Rel *rel, *rellim; 183 uintptr_t relocbase = 0; 184 Elf_Addr *where, target; 185 186 rel = __rel_iplt_start; 187 rellim = __rel_iplt_end; 188 for (; rel < rellim; ++rel) { 189 if (ELF_R_TYPE(rel->r_info) != R_TYPE(IRELATIVE)) 190 abort(); 191 where = (Elf_Addr *)(relocbase + rel->r_offset); 192 target = ((Elf_Addr(*)(void))*where)(); 193 *where = target; 194 } 195 } 196 #endif 197 198 void 199 ___start(void (*cleanup)(void), /* from shared loader */ 200 const Obj_Entry *obj, /* from shared loader */ 201 struct ps_strings *ps_strings) 202 { 203 204 if (ps_strings == NULL) 205 _FATAL("ps_strings missing\n"); 206 __ps_strings = ps_strings; 207 208 environ = ps_strings->ps_envstr; 209 210 if (ps_strings->ps_argvstr[0] != NULL) { 211 char *c; 212 __progname = ps_strings->ps_argvstr[0]; 213 for (c = ps_strings->ps_argvstr[0]; *c; ++c) { 214 if (*c == '/') 215 __progname = c + 1; 216 } 217 } else { 218 __progname = empty_string; 219 } 220 221 if (&rtld_DYNAMIC != NULL) { 222 if (obj == NULL) 223 _FATAL("NULL Obj_Entry pointer in GOT\n"); 224 if (obj->magic != RTLD_MAGIC) 225 _FATAL("Corrupt Obj_Entry pointer in GOT\n"); 226 if (obj->version != RTLD_VERSION) 227 _FATAL("Dynamic linker version mismatch\n"); 228 atexit(cleanup); 229 } 230 231 _libc_init(); 232 233 if (&rtld_DYNAMIC == NULL) { 234 #ifdef HAS_IPLTA 235 fix_iplta(); 236 #endif 237 #ifdef HAS_IPLT 238 fix_iplt(); 239 #endif 240 } 241 242 #ifdef HAVE_INITFINI_ARRAY 243 _preinit(); 244 #endif 245 246 #ifdef MCRT0 247 atexit(_mcleanup); 248 monstartup((u_long)&__eprol, (u_long)&__etext); 249 #endif 250 251 atexit(_fini); 252 _init(); 253 254 exit(main(ps_strings->ps_nargvstr, ps_strings->ps_argvstr, environ)); 255 } 256
Indexes created Thu Oct 02 01:09:59 GMT 2025