[279] | 1 | /*
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| 2 | * Tiny C Memory and bounds checker
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| 3 | *
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| 4 | * Copyright (c) 2002 Fabrice Bellard
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| 5 | *
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| 6 | * This library is free software; you can redistribute it and/or
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| 7 | * modify it under the terms of the GNU Lesser General Public
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| 8 | * License as published by the Free Software Foundation; either
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| 9 | * version 2 of the License, or (at your option) any later version.
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| 10 | *
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| 11 | * This library is distributed in the hope that it will be useful,
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| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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| 14 | * Lesser General Public License for more details.
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| 15 | *
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| 16 | * You should have received a copy of the GNU Lesser General Public
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| 17 | * License along with this library; if not, write to the Free Software
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| 18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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| 19 | */
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| 20 | #include <stdlib.h>
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| 21 | #include <stdio.h>
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| 22 | #include <stdarg.h>
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| 23 | #include <string.h>
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| 24 | #if !defined(__FreeBSD__) && !defined(__FreeBSD_kernel__) \
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| 25 | && !defined(__DragonFly__) && !defined(__OpenBSD__)
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| 26 | #include <malloc.h>
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| 27 | #endif
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| 28 | #if !defined(_WIN32)
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| 29 | #include <unistd.h>
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| 30 | #endif
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| 31 |
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| 32 | //#define BOUND_DEBUG
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| 33 |
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| 34 | /* define so that bound array is static (faster, but use memory if
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| 35 | bound checking not used) */
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| 36 | //#define BOUND_STATIC
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| 37 |
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| 38 | /* use malloc hooks. Currently the code cannot be reliable if no hooks */
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| 39 | #define CONFIG_TCC_MALLOC_HOOKS
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| 40 | #define HAVE_MEMALIGN
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| 41 |
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| 42 | #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) \
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| 43 | || defined(__DragonFly__) || defined(__dietlibc__) \
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| 44 | || defined(__UCLIBC__) || defined(__OpenBSD__) \
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| 45 | || defined(_WIN32) || defined(TCC_UCLIBC)
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| 46 | #warning Bound checking does not support malloc (etc.) in this environment.
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| 47 | #undef CONFIG_TCC_MALLOC_HOOKS
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| 48 | #undef HAVE_MEMALIGN
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| 49 | #endif
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| 50 |
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| 51 | #define BOUND_T1_BITS 13
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| 52 | #define BOUND_T2_BITS 11
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| 53 | #define BOUND_T3_BITS (32 - BOUND_T1_BITS - BOUND_T2_BITS)
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| 54 |
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| 55 | #define BOUND_T1_SIZE (1 << BOUND_T1_BITS)
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| 56 | #define BOUND_T2_SIZE (1 << BOUND_T2_BITS)
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| 57 | #define BOUND_T3_SIZE (1 << BOUND_T3_BITS)
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| 58 | #define BOUND_E_BITS 4
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| 59 |
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| 60 | #define BOUND_T23_BITS (BOUND_T2_BITS + BOUND_T3_BITS)
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| 61 | #define BOUND_T23_SIZE (1 << BOUND_T23_BITS)
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| 62 |
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| 63 |
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| 64 | /* this pointer is generated when bound check is incorrect */
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| 65 | #define INVALID_POINTER ((void *)(-2))
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| 66 | /* size of an empty region */
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| 67 | #define EMPTY_SIZE 0xffffffff
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| 68 | /* size of an invalid region */
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| 69 | #define INVALID_SIZE 0
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| 70 |
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| 71 | typedef struct BoundEntry {
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| 72 | unsigned long start;
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| 73 | unsigned long size;
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| 74 | struct BoundEntry *next;
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| 75 | unsigned long is_invalid; /* true if pointers outside region are invalid */
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| 76 | } BoundEntry;
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| 77 |
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| 78 | /* external interface */
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| 79 | void __bound_init(void);
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| 80 | void __bound_new_region(void *p, unsigned long size);
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| 81 | int __bound_delete_region(void *p);
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| 82 |
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| 83 | #define FASTCALL __attribute__((regparm(3)))
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| 84 |
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| 85 | void *__bound_malloc(size_t size, const void *caller);
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| 86 | void *__bound_memalign(size_t size, size_t align, const void *caller);
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| 87 | void __bound_free(void *ptr, const void *caller);
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| 88 | void *__bound_realloc(void *ptr, size_t size, const void *caller);
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| 89 | static void *libc_malloc(size_t size);
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| 90 | static void libc_free(void *ptr);
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| 91 | static void install_malloc_hooks(void);
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| 92 | static void restore_malloc_hooks(void);
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| 93 |
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| 94 | #ifdef CONFIG_TCC_MALLOC_HOOKS
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| 95 | static void *saved_malloc_hook;
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| 96 | static void *saved_free_hook;
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| 97 | static void *saved_realloc_hook;
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| 98 | static void *saved_memalign_hook;
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| 99 | #endif
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| 100 |
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| 101 | /* TCC definitions */
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| 102 | extern char __bounds_start; /* start of static bounds table */
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| 103 | /* error message, just for TCC */
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| 104 | const char *__bound_error_msg;
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| 105 |
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| 106 | /* runtime error output */
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| 107 | extern void rt_error(unsigned long pc, const char *fmt, ...);
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| 108 |
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| 109 | #ifdef BOUND_STATIC
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| 110 | static BoundEntry *__bound_t1[BOUND_T1_SIZE]; /* page table */
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| 111 | #else
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| 112 | static BoundEntry **__bound_t1; /* page table */
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| 113 | #endif
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| 114 | static BoundEntry *__bound_empty_t2; /* empty page, for unused pages */
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| 115 | static BoundEntry *__bound_invalid_t2; /* invalid page, for invalid pointers */
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| 116 |
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| 117 | static BoundEntry *__bound_find_region(BoundEntry *e1, void *p)
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| 118 | {
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| 119 | unsigned long addr, tmp;
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| 120 | BoundEntry *e;
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| 121 |
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| 122 | e = e1;
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| 123 | while (e != NULL) {
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| 124 | addr = (unsigned long)p;
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| 125 | addr -= e->start;
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| 126 | if (addr <= e->size) {
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| 127 | /* put region at the head */
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| 128 | tmp = e1->start;
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| 129 | e1->start = e->start;
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| 130 | e->start = tmp;
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| 131 | tmp = e1->size;
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| 132 | e1->size = e->size;
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| 133 | e->size = tmp;
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| 134 | return e1;
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| 135 | }
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| 136 | e = e->next;
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| 137 | }
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| 138 | /* no entry found: return empty entry or invalid entry */
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| 139 | if (e1->is_invalid)
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| 140 | return __bound_invalid_t2;
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| 141 | else
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| 142 | return __bound_empty_t2;
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| 143 | }
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| 144 |
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| 145 | /* print a bound error message */
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| 146 | static void bound_error(const char *fmt, ...)
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| 147 | {
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| 148 | __bound_error_msg = fmt;
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| 149 | *(int *)0 = 0; /* force a runtime error */
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| 150 | }
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| 151 |
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| 152 | static void bound_alloc_error(void)
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| 153 | {
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| 154 | bound_error("not enough memory for bound checking code");
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| 155 | }
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| 156 |
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| 157 | /* return '(p + offset)' for pointer arithmetic (a pointer can reach
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| 158 | the end of a region in this case */
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| 159 | void * FASTCALL __bound_ptr_add(void *p, int offset)
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| 160 | {
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| 161 | unsigned long addr = (unsigned long)p;
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| 162 | BoundEntry *e;
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| 163 | #if defined(BOUND_DEBUG)
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| 164 | printf("add: 0x%x %d\n", (int)p, offset);
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| 165 | #endif
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| 166 |
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| 167 | e = __bound_t1[addr >> (BOUND_T2_BITS + BOUND_T3_BITS)];
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| 168 | e = (BoundEntry *)((char *)e +
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| 169 | ((addr >> (BOUND_T3_BITS - BOUND_E_BITS)) &
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| 170 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS)));
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| 171 | addr -= e->start;
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| 172 | if (addr > e->size) {
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| 173 | e = __bound_find_region(e, p);
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| 174 | addr = (unsigned long)p - e->start;
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| 175 | }
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| 176 | addr += offset;
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| 177 | if (addr > e->size)
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| 178 | return INVALID_POINTER; /* return an invalid pointer */
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| 179 | return p + offset;
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| 180 | }
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| 181 |
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| 182 | /* return '(p + offset)' for pointer indirection (the resulting must
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| 183 | be strictly inside the region */
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| 184 | #define BOUND_PTR_INDIR(dsize) \
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| 185 | void * FASTCALL __bound_ptr_indir ## dsize (void *p, int offset) \
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| 186 | { \
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| 187 | unsigned long addr = (unsigned long)p; \
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| 188 | BoundEntry *e; \
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| 189 | \
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| 190 | e = __bound_t1[addr >> (BOUND_T2_BITS + BOUND_T3_BITS)]; \
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| 191 | e = (BoundEntry *)((char *)e + \
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| 192 | ((addr >> (BOUND_T3_BITS - BOUND_E_BITS)) & \
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| 193 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS))); \
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| 194 | addr -= e->start; \
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| 195 | if (addr > e->size) { \
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| 196 | e = __bound_find_region(e, p); \
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| 197 | addr = (unsigned long)p - e->start; \
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| 198 | } \
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| 199 | addr += offset + dsize; \
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| 200 | if (addr > e->size) \
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| 201 | return INVALID_POINTER; /* return an invalid pointer */ \
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| 202 | return p + offset; \
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| 203 | }
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| 204 |
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| 205 | BOUND_PTR_INDIR(1)
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| 206 | BOUND_PTR_INDIR(2)
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| 207 | BOUND_PTR_INDIR(4)
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| 208 | BOUND_PTR_INDIR(8)
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| 209 | BOUND_PTR_INDIR(12)
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| 210 | BOUND_PTR_INDIR(16)
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| 211 |
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| 212 | /* return the frame pointer of the caller */
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| 213 | #define GET_CALLER_FP(fp)\
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| 214 | {\
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| 215 | fp = (unsigned long)__builtin_frame_address(1);\
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| 216 | }
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| 217 |
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| 218 | /* called when entering a function to add all the local regions */
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| 219 | void FASTCALL __bound_local_new(void *p1)
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| 220 | {
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| 221 | unsigned long addr, size, fp, *p = p1;
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| 222 | GET_CALLER_FP(fp);
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| 223 | for(;;) {
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| 224 | addr = p[0];
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| 225 | if (addr == 0)
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| 226 | break;
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| 227 | addr += fp;
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| 228 | size = p[1];
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| 229 | p += 2;
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| 230 | __bound_new_region((void *)addr, size);
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| 231 | }
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| 232 | }
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| 233 |
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| 234 | /* called when leaving a function to delete all the local regions */
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| 235 | void FASTCALL __bound_local_delete(void *p1)
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| 236 | {
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| 237 | unsigned long addr, fp, *p = p1;
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| 238 | GET_CALLER_FP(fp);
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| 239 | for(;;) {
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| 240 | addr = p[0];
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| 241 | if (addr == 0)
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| 242 | break;
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| 243 | addr += fp;
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| 244 | p += 2;
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| 245 | __bound_delete_region((void *)addr);
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| 246 | }
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| 247 | }
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| 248 |
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| 249 | static BoundEntry *__bound_new_page(void)
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| 250 | {
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| 251 | BoundEntry *page;
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| 252 | int i;
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| 253 |
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| 254 | page = libc_malloc(sizeof(BoundEntry) * BOUND_T2_SIZE);
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| 255 | if (!page)
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| 256 | bound_alloc_error();
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| 257 | for(i=0;i<BOUND_T2_SIZE;i++) {
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| 258 | /* put empty entries */
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| 259 | page[i].start = 0;
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| 260 | page[i].size = EMPTY_SIZE;
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| 261 | page[i].next = NULL;
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| 262 | page[i].is_invalid = 0;
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| 263 | }
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| 264 | return page;
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| 265 | }
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| 266 |
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| 267 | /* currently we use malloc(). Should use bound_new_page() */
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| 268 | static BoundEntry *bound_new_entry(void)
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| 269 | {
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| 270 | BoundEntry *e;
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| 271 | e = libc_malloc(sizeof(BoundEntry));
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| 272 | return e;
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| 273 | }
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| 274 |
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| 275 | static void bound_free_entry(BoundEntry *e)
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| 276 | {
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| 277 | libc_free(e);
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| 278 | }
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| 279 |
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| 280 | static inline BoundEntry *get_page(int index)
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| 281 | {
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| 282 | BoundEntry *page;
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| 283 | page = __bound_t1[index];
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| 284 | if (page == __bound_empty_t2 || page == __bound_invalid_t2) {
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| 285 | /* create a new page if necessary */
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| 286 | page = __bound_new_page();
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| 287 | __bound_t1[index] = page;
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| 288 | }
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| 289 | return page;
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| 290 | }
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| 291 |
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| 292 | /* mark a region as being invalid (can only be used during init) */
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| 293 | static void mark_invalid(unsigned long addr, unsigned long size)
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| 294 | {
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| 295 | unsigned long start, end;
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| 296 | BoundEntry *page;
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| 297 | int t1_start, t1_end, i, j, t2_start, t2_end;
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| 298 |
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| 299 | start = addr;
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| 300 | end = addr + size;
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| 301 |
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| 302 | t2_start = (start + BOUND_T3_SIZE - 1) >> BOUND_T3_BITS;
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| 303 | if (end != 0)
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| 304 | t2_end = end >> BOUND_T3_BITS;
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| 305 | else
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| 306 | t2_end = 1 << (BOUND_T1_BITS + BOUND_T2_BITS);
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| 307 |
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| 308 | #if 0
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| 309 | printf("mark_invalid: start = %x %x\n", t2_start, t2_end);
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| 310 | #endif
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| 311 |
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| 312 | /* first we handle full pages */
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| 313 | t1_start = (t2_start + BOUND_T2_SIZE - 1) >> BOUND_T2_BITS;
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| 314 | t1_end = t2_end >> BOUND_T2_BITS;
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| 315 |
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| 316 | i = t2_start & (BOUND_T2_SIZE - 1);
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| 317 | j = t2_end & (BOUND_T2_SIZE - 1);
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| 318 |
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| 319 | if (t1_start == t1_end) {
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| 320 | page = get_page(t2_start >> BOUND_T2_BITS);
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| 321 | for(; i < j; i++) {
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| 322 | page[i].size = INVALID_SIZE;
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| 323 | page[i].is_invalid = 1;
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| 324 | }
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| 325 | } else {
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| 326 | if (i > 0) {
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| 327 | page = get_page(t2_start >> BOUND_T2_BITS);
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| 328 | for(; i < BOUND_T2_SIZE; i++) {
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| 329 | page[i].size = INVALID_SIZE;
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| 330 | page[i].is_invalid = 1;
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| 331 | }
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| 332 | }
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| 333 | for(i = t1_start; i < t1_end; i++) {
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| 334 | __bound_t1[i] = __bound_invalid_t2;
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| 335 | }
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| 336 | if (j != 0) {
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| 337 | page = get_page(t1_end);
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| 338 | for(i = 0; i < j; i++) {
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| 339 | page[i].size = INVALID_SIZE;
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| 340 | page[i].is_invalid = 1;
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| 341 | }
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| 342 | }
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| 343 | }
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| 344 | }
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| 345 |
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| 346 | void __bound_init(void)
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| 347 | {
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| 348 | int i;
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| 349 | BoundEntry *page;
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| 350 | unsigned long start, size;
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| 351 | int *p;
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| 352 |
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| 353 | /* save malloc hooks and install bound check hooks */
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| 354 | install_malloc_hooks();
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| 355 |
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| 356 | #ifndef BOUND_STATIC
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| 357 | __bound_t1 = libc_malloc(BOUND_T1_SIZE * sizeof(BoundEntry *));
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| 358 | if (!__bound_t1)
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| 359 | bound_alloc_error();
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| 360 | #endif
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| 361 | __bound_empty_t2 = __bound_new_page();
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| 362 | for(i=0;i<BOUND_T1_SIZE;i++) {
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| 363 | __bound_t1[i] = __bound_empty_t2;
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| 364 | }
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| 365 |
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| 366 | page = __bound_new_page();
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| 367 | for(i=0;i<BOUND_T2_SIZE;i++) {
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| 368 | /* put invalid entries */
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| 369 | page[i].start = 0;
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| 370 | page[i].size = INVALID_SIZE;
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| 371 | page[i].next = NULL;
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| 372 | page[i].is_invalid = 1;
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| 373 | }
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| 374 | __bound_invalid_t2 = page;
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| 375 |
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| 376 | /* invalid pointer zone */
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| 377 | start = (unsigned long)INVALID_POINTER & ~(BOUND_T23_SIZE - 1);
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| 378 | size = BOUND_T23_SIZE;
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| 379 | mark_invalid(start, size);
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| 380 |
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| 381 | #if defined(CONFIG_TCC_MALLOC_HOOKS)
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| 382 | /* malloc zone is also marked invalid. can only use that with
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| 383 | * hooks because all libs should use the same malloc. The solution
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| 384 | * would be to build a new malloc for tcc.
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| 385 | *
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| 386 | * usually heap (= malloc zone) comes right after bss, i.e. after _end, but
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| 387 | * not always - either if we are running from under `tcc -b -run`, or if
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| 388 | * address space randomization is turned on(a), heap start will be separated
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| 389 | * from bss end.
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| 390 | *
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| 391 | * So sbrk(0) will be a good approximation for start_brk:
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| 392 | *
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| 393 | * - if we are a separately compiled program, __bound_init() runs early,
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| 394 | * and sbrk(0) should be equal or very near to start_brk(b) (in case other
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| 395 | * constructors malloc something), or
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| 396 | *
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| 397 | * - if we are running from under `tcc -b -run`, sbrk(0) will return
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| 398 | * start of heap portion which is under this program control, and not
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| 399 | * mark as invalid earlier allocated memory.
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| 400 | *
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| 401 | *
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| 402 | * (a) /proc/sys/kernel/randomize_va_space = 2, on Linux;
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| 403 | * usually turned on by default.
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| 404 | *
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| 405 | * (b) on Linux >= v3.3, the alternative is to read
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| 406 | * start_brk from /proc/self/stat
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| 407 | */
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| 408 | start = (unsigned long)sbrk(0);
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| 409 | size = 128 * 0x100000;
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| 410 | mark_invalid(start, size);
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| 411 | #endif
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| 412 |
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| 413 | /* add all static bound check values */
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| 414 | p = (int *)&__bounds_start;
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| 415 | while (p[0] != 0) {
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| 416 | __bound_new_region((void *)p[0], p[1]);
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| 417 | p += 2;
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| 418 | }
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| 419 | }
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| 420 |
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| 421 | void __bound_exit(void)
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| 422 | {
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| 423 | restore_malloc_hooks();
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| 424 | }
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| 425 |
|
---|
| 426 | static inline void add_region(BoundEntry *e,
|
---|
| 427 | unsigned long start, unsigned long size)
|
---|
| 428 | {
|
---|
| 429 | BoundEntry *e1;
|
---|
| 430 | if (e->start == 0) {
|
---|
| 431 | /* no region : add it */
|
---|
| 432 | e->start = start;
|
---|
| 433 | e->size = size;
|
---|
| 434 | } else {
|
---|
| 435 | /* already regions in the list: add it at the head */
|
---|
| 436 | e1 = bound_new_entry();
|
---|
| 437 | e1->start = e->start;
|
---|
| 438 | e1->size = e->size;
|
---|
| 439 | e1->next = e->next;
|
---|
| 440 | e->start = start;
|
---|
| 441 | e->size = size;
|
---|
| 442 | e->next = e1;
|
---|
| 443 | }
|
---|
| 444 | }
|
---|
| 445 |
|
---|
| 446 | /* create a new region. It should not already exist in the region list */
|
---|
| 447 | void __bound_new_region(void *p, unsigned long size)
|
---|
| 448 | {
|
---|
| 449 | unsigned long start, end;
|
---|
| 450 | BoundEntry *page, *e, *e2;
|
---|
| 451 | int t1_start, t1_end, i, t2_start, t2_end;
|
---|
| 452 |
|
---|
| 453 | start = (unsigned long)p;
|
---|
| 454 | end = start + size;
|
---|
| 455 | t1_start = start >> (BOUND_T2_BITS + BOUND_T3_BITS);
|
---|
| 456 | t1_end = end >> (BOUND_T2_BITS + BOUND_T3_BITS);
|
---|
| 457 |
|
---|
| 458 | /* start */
|
---|
| 459 | page = get_page(t1_start);
|
---|
| 460 | t2_start = (start >> (BOUND_T3_BITS - BOUND_E_BITS)) &
|
---|
| 461 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
|
---|
| 462 | t2_end = (end >> (BOUND_T3_BITS - BOUND_E_BITS)) &
|
---|
| 463 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
|
---|
| 464 | #ifdef BOUND_DEBUG
|
---|
| 465 | printf("new %lx %lx %x %x %x %x\n",
|
---|
| 466 | start, end, t1_start, t1_end, t2_start, t2_end);
|
---|
| 467 | #endif
|
---|
| 468 |
|
---|
| 469 | e = (BoundEntry *)((char *)page + t2_start);
|
---|
| 470 | add_region(e, start, size);
|
---|
| 471 |
|
---|
| 472 | if (t1_end == t1_start) {
|
---|
| 473 | /* same ending page */
|
---|
| 474 | e2 = (BoundEntry *)((char *)page + t2_end);
|
---|
| 475 | if (e2 > e) {
|
---|
| 476 | e++;
|
---|
| 477 | for(;e<e2;e++) {
|
---|
| 478 | e->start = start;
|
---|
| 479 | e->size = size;
|
---|
| 480 | }
|
---|
| 481 | add_region(e, start, size);
|
---|
| 482 | }
|
---|
| 483 | } else {
|
---|
| 484 | /* mark until end of page */
|
---|
| 485 | e2 = page + BOUND_T2_SIZE;
|
---|
| 486 | e++;
|
---|
| 487 | for(;e<e2;e++) {
|
---|
| 488 | e->start = start;
|
---|
| 489 | e->size = size;
|
---|
| 490 | }
|
---|
| 491 | /* mark intermediate pages, if any */
|
---|
| 492 | for(i=t1_start+1;i<t1_end;i++) {
|
---|
| 493 | page = get_page(i);
|
---|
| 494 | e2 = page + BOUND_T2_SIZE;
|
---|
| 495 | for(e=page;e<e2;e++) {
|
---|
| 496 | e->start = start;
|
---|
| 497 | e->size = size;
|
---|
| 498 | }
|
---|
| 499 | }
|
---|
| 500 | /* last page */
|
---|
| 501 | page = get_page(t1_end);
|
---|
| 502 | e2 = (BoundEntry *)((char *)page + t2_end);
|
---|
| 503 | for(e=page;e<e2;e++) {
|
---|
| 504 | e->start = start;
|
---|
| 505 | e->size = size;
|
---|
| 506 | }
|
---|
| 507 | add_region(e, start, size);
|
---|
| 508 | }
|
---|
| 509 | }
|
---|
| 510 |
|
---|
| 511 | /* delete a region */
|
---|
| 512 | static inline void delete_region(BoundEntry *e,
|
---|
| 513 | void *p, unsigned long empty_size)
|
---|
| 514 | {
|
---|
| 515 | unsigned long addr;
|
---|
| 516 | BoundEntry *e1;
|
---|
| 517 |
|
---|
| 518 | addr = (unsigned long)p;
|
---|
| 519 | addr -= e->start;
|
---|
| 520 | if (addr <= e->size) {
|
---|
| 521 | /* region found is first one */
|
---|
| 522 | e1 = e->next;
|
---|
| 523 | if (e1 == NULL) {
|
---|
| 524 | /* no more region: mark it empty */
|
---|
| 525 | e->start = 0;
|
---|
| 526 | e->size = empty_size;
|
---|
| 527 | } else {
|
---|
| 528 | /* copy next region in head */
|
---|
| 529 | e->start = e1->start;
|
---|
| 530 | e->size = e1->size;
|
---|
| 531 | e->next = e1->next;
|
---|
| 532 | bound_free_entry(e1);
|
---|
| 533 | }
|
---|
| 534 | } else {
|
---|
| 535 | /* find the matching region */
|
---|
| 536 | for(;;) {
|
---|
| 537 | e1 = e;
|
---|
| 538 | e = e->next;
|
---|
| 539 | /* region not found: do nothing */
|
---|
| 540 | if (e == NULL)
|
---|
| 541 | break;
|
---|
| 542 | addr = (unsigned long)p - e->start;
|
---|
| 543 | if (addr <= e->size) {
|
---|
| 544 | /* found: remove entry */
|
---|
| 545 | e1->next = e->next;
|
---|
| 546 | bound_free_entry(e);
|
---|
| 547 | break;
|
---|
| 548 | }
|
---|
| 549 | }
|
---|
| 550 | }
|
---|
| 551 | }
|
---|
| 552 |
|
---|
| 553 | /* WARNING: 'p' must be the starting point of the region. */
|
---|
| 554 | /* return non zero if error */
|
---|
| 555 | int __bound_delete_region(void *p)
|
---|
| 556 | {
|
---|
| 557 | unsigned long start, end, addr, size, empty_size;
|
---|
| 558 | BoundEntry *page, *e, *e2;
|
---|
| 559 | int t1_start, t1_end, t2_start, t2_end, i;
|
---|
| 560 |
|
---|
| 561 | start = (unsigned long)p;
|
---|
| 562 | t1_start = start >> (BOUND_T2_BITS + BOUND_T3_BITS);
|
---|
| 563 | t2_start = (start >> (BOUND_T3_BITS - BOUND_E_BITS)) &
|
---|
| 564 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
|
---|
| 565 |
|
---|
| 566 | /* find region size */
|
---|
| 567 | page = __bound_t1[t1_start];
|
---|
| 568 | e = (BoundEntry *)((char *)page + t2_start);
|
---|
| 569 | addr = start - e->start;
|
---|
| 570 | if (addr > e->size)
|
---|
| 571 | e = __bound_find_region(e, p);
|
---|
| 572 | /* test if invalid region */
|
---|
| 573 | if (e->size == EMPTY_SIZE || (unsigned long)p != e->start)
|
---|
| 574 | return -1;
|
---|
| 575 | /* compute the size we put in invalid regions */
|
---|
| 576 | if (e->is_invalid)
|
---|
| 577 | empty_size = INVALID_SIZE;
|
---|
| 578 | else
|
---|
| 579 | empty_size = EMPTY_SIZE;
|
---|
| 580 | size = e->size;
|
---|
| 581 | end = start + size;
|
---|
| 582 |
|
---|
| 583 | /* now we can free each entry */
|
---|
| 584 | t1_end = end >> (BOUND_T2_BITS + BOUND_T3_BITS);
|
---|
| 585 | t2_end = (end >> (BOUND_T3_BITS - BOUND_E_BITS)) &
|
---|
| 586 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS);
|
---|
| 587 |
|
---|
| 588 | delete_region(e, p, empty_size);
|
---|
| 589 | if (t1_end == t1_start) {
|
---|
| 590 | /* same ending page */
|
---|
| 591 | e2 = (BoundEntry *)((char *)page + t2_end);
|
---|
| 592 | if (e2 > e) {
|
---|
| 593 | e++;
|
---|
| 594 | for(;e<e2;e++) {
|
---|
| 595 | e->start = 0;
|
---|
| 596 | e->size = empty_size;
|
---|
| 597 | }
|
---|
| 598 | delete_region(e, p, empty_size);
|
---|
| 599 | }
|
---|
| 600 | } else {
|
---|
| 601 | /* mark until end of page */
|
---|
| 602 | e2 = page + BOUND_T2_SIZE;
|
---|
| 603 | e++;
|
---|
| 604 | for(;e<e2;e++) {
|
---|
| 605 | e->start = 0;
|
---|
| 606 | e->size = empty_size;
|
---|
| 607 | }
|
---|
| 608 | /* mark intermediate pages, if any */
|
---|
| 609 | /* XXX: should free them */
|
---|
| 610 | for(i=t1_start+1;i<t1_end;i++) {
|
---|
| 611 | page = get_page(i);
|
---|
| 612 | e2 = page + BOUND_T2_SIZE;
|
---|
| 613 | for(e=page;e<e2;e++) {
|
---|
| 614 | e->start = 0;
|
---|
| 615 | e->size = empty_size;
|
---|
| 616 | }
|
---|
| 617 | }
|
---|
| 618 | /* last page */
|
---|
| 619 | page = get_page(t1_end);
|
---|
| 620 | e2 = (BoundEntry *)((char *)page + t2_end);
|
---|
| 621 | for(e=page;e<e2;e++) {
|
---|
| 622 | e->start = 0;
|
---|
| 623 | e->size = empty_size;
|
---|
| 624 | }
|
---|
| 625 | delete_region(e, p, empty_size);
|
---|
| 626 | }
|
---|
| 627 | return 0;
|
---|
| 628 | }
|
---|
| 629 |
|
---|
| 630 | /* return the size of the region starting at p, or EMPTY_SIZE if non
|
---|
| 631 | existant region. */
|
---|
| 632 | static unsigned long get_region_size(void *p)
|
---|
| 633 | {
|
---|
| 634 | unsigned long addr = (unsigned long)p;
|
---|
| 635 | BoundEntry *e;
|
---|
| 636 |
|
---|
| 637 | e = __bound_t1[addr >> (BOUND_T2_BITS + BOUND_T3_BITS)];
|
---|
| 638 | e = (BoundEntry *)((char *)e +
|
---|
| 639 | ((addr >> (BOUND_T3_BITS - BOUND_E_BITS)) &
|
---|
| 640 | ((BOUND_T2_SIZE - 1) << BOUND_E_BITS)));
|
---|
| 641 | addr -= e->start;
|
---|
| 642 | if (addr > e->size)
|
---|
| 643 | e = __bound_find_region(e, p);
|
---|
| 644 | if (e->start != (unsigned long)p)
|
---|
| 645 | return EMPTY_SIZE;
|
---|
| 646 | return e->size;
|
---|
| 647 | }
|
---|
| 648 |
|
---|
| 649 | /* patched memory functions */
|
---|
| 650 |
|
---|
| 651 | /* force compiler to perform stores coded up to this point */
|
---|
| 652 | #define barrier() __asm__ __volatile__ ("": : : "memory")
|
---|
| 653 |
|
---|
| 654 | static void install_malloc_hooks(void)
|
---|
| 655 | {
|
---|
| 656 | #ifdef CONFIG_TCC_MALLOC_HOOKS
|
---|
| 657 | saved_malloc_hook = __malloc_hook;
|
---|
| 658 | saved_free_hook = __free_hook;
|
---|
| 659 | saved_realloc_hook = __realloc_hook;
|
---|
| 660 | saved_memalign_hook = __memalign_hook;
|
---|
| 661 | __malloc_hook = __bound_malloc;
|
---|
| 662 | __free_hook = __bound_free;
|
---|
| 663 | __realloc_hook = __bound_realloc;
|
---|
| 664 | __memalign_hook = __bound_memalign;
|
---|
| 665 |
|
---|
| 666 | barrier();
|
---|
| 667 | #endif
|
---|
| 668 | }
|
---|
| 669 |
|
---|
| 670 | static void restore_malloc_hooks(void)
|
---|
| 671 | {
|
---|
| 672 | #ifdef CONFIG_TCC_MALLOC_HOOKS
|
---|
| 673 | __malloc_hook = saved_malloc_hook;
|
---|
| 674 | __free_hook = saved_free_hook;
|
---|
| 675 | __realloc_hook = saved_realloc_hook;
|
---|
| 676 | __memalign_hook = saved_memalign_hook;
|
---|
| 677 |
|
---|
| 678 | barrier();
|
---|
| 679 | #endif
|
---|
| 680 | }
|
---|
| 681 |
|
---|
| 682 | static void *libc_malloc(size_t size)
|
---|
| 683 | {
|
---|
| 684 | void *ptr;
|
---|
| 685 | restore_malloc_hooks();
|
---|
| 686 | ptr = malloc(size);
|
---|
| 687 | install_malloc_hooks();
|
---|
| 688 | return ptr;
|
---|
| 689 | }
|
---|
| 690 |
|
---|
| 691 | static void libc_free(void *ptr)
|
---|
| 692 | {
|
---|
| 693 | restore_malloc_hooks();
|
---|
| 694 | free(ptr);
|
---|
| 695 | install_malloc_hooks();
|
---|
| 696 | }
|
---|
| 697 |
|
---|
| 698 | /* XXX: we should use a malloc which ensure that it is unlikely that
|
---|
| 699 | two malloc'ed data have the same address if 'free' are made in
|
---|
| 700 | between. */
|
---|
| 701 | void *__bound_malloc(size_t size, const void *caller)
|
---|
| 702 | {
|
---|
| 703 | void *ptr;
|
---|
| 704 |
|
---|
| 705 | /* we allocate one more byte to ensure the regions will be
|
---|
| 706 | separated by at least one byte. With the glibc malloc, it may
|
---|
| 707 | be in fact not necessary */
|
---|
| 708 | ptr = libc_malloc(size + 1);
|
---|
| 709 |
|
---|
| 710 | if (!ptr)
|
---|
| 711 | return NULL;
|
---|
| 712 | __bound_new_region(ptr, size);
|
---|
| 713 | return ptr;
|
---|
| 714 | }
|
---|
| 715 |
|
---|
| 716 | void *__bound_memalign(size_t size, size_t align, const void *caller)
|
---|
| 717 | {
|
---|
| 718 | void *ptr;
|
---|
| 719 |
|
---|
| 720 | restore_malloc_hooks();
|
---|
| 721 |
|
---|
| 722 | #ifndef HAVE_MEMALIGN
|
---|
| 723 | if (align > 4) {
|
---|
| 724 | /* XXX: handle it ? */
|
---|
| 725 | ptr = NULL;
|
---|
| 726 | } else {
|
---|
| 727 | /* we suppose that malloc aligns to at least four bytes */
|
---|
| 728 | ptr = malloc(size + 1);
|
---|
| 729 | }
|
---|
| 730 | #else
|
---|
| 731 | /* we allocate one more byte to ensure the regions will be
|
---|
| 732 | separated by at least one byte. With the glibc malloc, it may
|
---|
| 733 | be in fact not necessary */
|
---|
| 734 | ptr = memalign(size + 1, align);
|
---|
| 735 | #endif
|
---|
| 736 |
|
---|
| 737 | install_malloc_hooks();
|
---|
| 738 |
|
---|
| 739 | if (!ptr)
|
---|
| 740 | return NULL;
|
---|
| 741 | __bound_new_region(ptr, size);
|
---|
| 742 | return ptr;
|
---|
| 743 | }
|
---|
| 744 |
|
---|
| 745 | void __bound_free(void *ptr, const void *caller)
|
---|
| 746 | {
|
---|
| 747 | if (ptr == NULL)
|
---|
| 748 | return;
|
---|
| 749 | if (__bound_delete_region(ptr) != 0)
|
---|
| 750 | bound_error("freeing invalid region");
|
---|
| 751 |
|
---|
| 752 | libc_free(ptr);
|
---|
| 753 | }
|
---|
| 754 |
|
---|
| 755 | void *__bound_realloc(void *ptr, size_t size, const void *caller)
|
---|
| 756 | {
|
---|
| 757 | void *ptr1;
|
---|
| 758 | int old_size;
|
---|
| 759 |
|
---|
| 760 | if (size == 0) {
|
---|
| 761 | __bound_free(ptr, caller);
|
---|
| 762 | return NULL;
|
---|
| 763 | } else {
|
---|
| 764 | ptr1 = __bound_malloc(size, caller);
|
---|
| 765 | if (ptr == NULL || ptr1 == NULL)
|
---|
| 766 | return ptr1;
|
---|
| 767 | old_size = get_region_size(ptr);
|
---|
| 768 | if (old_size == EMPTY_SIZE)
|
---|
| 769 | bound_error("realloc'ing invalid pointer");
|
---|
| 770 | memcpy(ptr1, ptr, old_size);
|
---|
| 771 | __bound_free(ptr, caller);
|
---|
| 772 | return ptr1;
|
---|
| 773 | }
|
---|
| 774 | }
|
---|
| 775 |
|
---|
| 776 | #ifndef CONFIG_TCC_MALLOC_HOOKS
|
---|
| 777 | void *__bound_calloc(size_t nmemb, size_t size)
|
---|
| 778 | {
|
---|
| 779 | void *ptr;
|
---|
| 780 | size = size * nmemb;
|
---|
| 781 | ptr = __bound_malloc(size, NULL);
|
---|
| 782 | if (!ptr)
|
---|
| 783 | return NULL;
|
---|
| 784 | memset(ptr, 0, size);
|
---|
| 785 | return ptr;
|
---|
| 786 | }
|
---|
| 787 | #endif
|
---|
| 788 |
|
---|
| 789 | #if 0
|
---|
| 790 | static void bound_dump(void)
|
---|
| 791 | {
|
---|
| 792 | BoundEntry *page, *e;
|
---|
| 793 | int i, j;
|
---|
| 794 |
|
---|
| 795 | printf("region dump:\n");
|
---|
| 796 | for(i=0;i<BOUND_T1_SIZE;i++) {
|
---|
| 797 | page = __bound_t1[i];
|
---|
| 798 | for(j=0;j<BOUND_T2_SIZE;j++) {
|
---|
| 799 | e = page + j;
|
---|
| 800 | /* do not print invalid or empty entries */
|
---|
| 801 | if (e->size != EMPTY_SIZE && e->start != 0) {
|
---|
| 802 | printf("%08x:",
|
---|
| 803 | (i << (BOUND_T2_BITS + BOUND_T3_BITS)) +
|
---|
| 804 | (j << BOUND_T3_BITS));
|
---|
| 805 | do {
|
---|
| 806 | printf(" %08lx:%08lx", e->start, e->start + e->size);
|
---|
| 807 | e = e->next;
|
---|
| 808 | } while (e != NULL);
|
---|
| 809 | printf("\n");
|
---|
| 810 | }
|
---|
| 811 | }
|
---|
| 812 | }
|
---|
| 813 | }
|
---|
| 814 | #endif
|
---|
| 815 |
|
---|
| 816 | /* some useful checked functions */
|
---|
| 817 |
|
---|
| 818 | /* check that (p ... p + size - 1) lies inside 'p' region, if any */
|
---|
| 819 | static void __bound_check(const void *p, size_t size)
|
---|
| 820 | {
|
---|
| 821 | if (size == 0)
|
---|
| 822 | return;
|
---|
| 823 | p = __bound_ptr_add((void *)p, size);
|
---|
| 824 | if (p == INVALID_POINTER)
|
---|
| 825 | bound_error("invalid pointer");
|
---|
| 826 | }
|
---|
| 827 |
|
---|
| 828 | void *__bound_memcpy(void *dst, const void *src, size_t size)
|
---|
| 829 | {
|
---|
| 830 | __bound_check(dst, size);
|
---|
| 831 | __bound_check(src, size);
|
---|
| 832 | /* check also region overlap */
|
---|
| 833 | if (src >= dst && src < dst + size)
|
---|
| 834 | bound_error("overlapping regions in memcpy()");
|
---|
| 835 | return memcpy(dst, src, size);
|
---|
| 836 | }
|
---|
| 837 |
|
---|
| 838 | void *__bound_memmove(void *dst, const void *src, size_t size)
|
---|
| 839 | {
|
---|
| 840 | __bound_check(dst, size);
|
---|
| 841 | __bound_check(src, size);
|
---|
| 842 | return memmove(dst, src, size);
|
---|
| 843 | }
|
---|
| 844 |
|
---|
| 845 | void *__bound_memset(void *dst, int c, size_t size)
|
---|
| 846 | {
|
---|
| 847 | __bound_check(dst, size);
|
---|
| 848 | return memset(dst, c, size);
|
---|
| 849 | }
|
---|
| 850 |
|
---|
| 851 | /* XXX: could be optimized */
|
---|
| 852 | int __bound_strlen(const char *s)
|
---|
| 853 | {
|
---|
| 854 | const char *p;
|
---|
| 855 | int len;
|
---|
| 856 |
|
---|
| 857 | len = 0;
|
---|
| 858 | for(;;) {
|
---|
| 859 | p = __bound_ptr_indir1((char *)s, len);
|
---|
| 860 | if (p == INVALID_POINTER)
|
---|
| 861 | bound_error("bad pointer in strlen()");
|
---|
| 862 | if (*p == '\0')
|
---|
| 863 | break;
|
---|
| 864 | len++;
|
---|
| 865 | }
|
---|
| 866 | return len;
|
---|
| 867 | }
|
---|
| 868 |
|
---|
| 869 | char *__bound_strcpy(char *dst, const char *src)
|
---|
| 870 | {
|
---|
| 871 | int len;
|
---|
| 872 | len = __bound_strlen(src);
|
---|
| 873 | return __bound_memcpy(dst, src, len + 1);
|
---|
| 874 | }
|
---|
| 875 |
|
---|