1 /* Copyright (C) 2021 Free Software Foundation, Inc. 2 Contributed by Oracle. 3 4 This file is part of GNU Binutils. 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3, or (at your option) 9 any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, 51 Franklin Street - Fifth Floor, Boston, 19 MA 02110-1301, USA. */ 20 21 #include "config.h" 22 #include <dlfcn.h> 23 #include "util.h" 24 25 #define CHECK_OUT_OF_MEM(ptr, size) if (ptr == NULL) err_out_of_memory(size) 26 27 /* Report Out of Memory error and exit */ 28 static void 29 err_out_of_memory (unsigned nbytes) 30 { 31 char *nm = get_prog_name (1); 32 if (nm) 33 fprintf (stderr, GTXT ("%s: Error: Memory capacity exceeded.\n"), nm); 34 else 35 fprintf (stderr, GTXT ("Error: Memory capacity exceeded.\n")); 36 fprintf (stderr, GTXT (" Requested %u bytes.\n"), nbytes); 37 exit (16); 38 } 39 40 #define CALL_REAL(x) (__real_##x) 41 #define NULL_PTR(x) ( __real_##x == NULL ) 42 43 static void *(*__real_malloc)(size_t) = NULL; 44 static void (*__real_free)(void *) = NULL; 45 static void *(*__real_realloc)(void *, size_t) = NULL; 46 static void *(*__real_calloc)(size_t, size_t) = NULL; 47 static char *(*__real_strdup)(const char*) = NULL; 48 static volatile int in_init = 0; 49 50 static int 51 init_heap_intf () 52 { 53 in_init = 1; 54 __real_malloc = (void*(*)(size_t))dlsym (RTLD_NEXT, "malloc"); 55 __real_free = (void(*)(void *))dlsym (RTLD_NEXT, "free"); 56 __real_realloc = (void*(*)(void *, size_t))dlsym (RTLD_NEXT, "realloc"); 57 __real_calloc = (void*(*)(size_t, size_t))dlsym (RTLD_NEXT, "calloc"); 58 __real_strdup = (char*(*)(const char*))dlsym (RTLD_NEXT, "strdup"); 59 in_init = 0; 60 return 0; 61 } 62 63 /* --------------------------------------------------------------------------- */ 64 /* libc's memory management functions substitutions */ 65 66 /* Allocate memory and make sure we got some */ 67 void * 68 malloc (size_t size) 69 { 70 if (NULL_PTR (malloc)) 71 init_heap_intf (); 72 void *ptr = CALL_REAL (malloc)(size); 73 CHECK_OUT_OF_MEM (ptr, size); 74 return ptr; 75 } 76 77 78 /* Implement a workaround for a libdl recursion problem */ 79 void * 80 calloc (size_t nelem, size_t size) 81 { 82 if (NULL_PTR (calloc)) 83 { 84 /* If a program is linked with libpthread then the following 85 * calling sequence occurs: 86 * init_heap_intf -> dlsym -> calloc -> malloc -> init_heap_intf 87 * We break some performance improvement in libdl by returning 88 * NULL but preserve functionality. 89 */ 90 if (in_init) 91 return NULL; 92 init_heap_intf (); 93 } 94 return CALL_REAL (calloc)(nelem, size); 95 } 96 97 /* Free the storage associated with data */ 98 void 99 free (void *ptr) 100 { 101 if (ptr == NULL) 102 return; 103 if (NULL_PTR (free)) 104 init_heap_intf (); 105 CALL_REAL (free)(ptr); 106 return; 107 } 108 109 /* Reallocate buffer */ 110 void * 111 realloc (void *ptr, size_t size) 112 { 113 if (NULL_PTR (realloc)) 114 init_heap_intf (); 115 ptr = CALL_REAL (realloc)(ptr, size); 116 CHECK_OUT_OF_MEM (ptr, size); 117 return ptr; 118 } 119