1 #include <unistd.h> 2 #include "tests/sys_mman.h" 3 #include <assert.h> 4 #include <stdlib.h> 5 6 #include "../memcheck.h" 7 8 #define SUPERBLOCK_SIZE 100000 9 10 //------------------------------------------------------------------------- 11 // Allocator 12 //------------------------------------------------------------------------- 13 14 void* get_superblock(void) 15 { 16 void* p = mmap( 0, SUPERBLOCK_SIZE, PROT_READ|PROT_WRITE|PROT_EXEC, 17 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0 ); 18 19 assert(p != ((void*)(-1))); 20 21 // Mark it no access; although it's addressible we don't want the 22 // program to be using it unless its handed out by custom_alloc() 23 24 // with redzones, better not to have it 25 VALGRIND_MAKE_MEM_NOACCESS(p, SUPERBLOCK_SIZE); 26 27 return p; 28 } 29 30 // has a redzone 31 static void* custom_alloc(int size) 32 { 33 #define RZ 8 34 static void* hp = 0; // current heap pointer 35 static void* hp_lim = 0; // maximum usable byte in current block 36 int size2 = size + RZ*2; 37 void* p; 38 39 if (hp + size2 > hp_lim) { 40 hp = get_superblock(); 41 hp_lim = hp + SUPERBLOCK_SIZE - 1; 42 } 43 44 p = hp + RZ; 45 hp += size2; 46 47 VALGRIND_MALLOCLIKE_BLOCK( p, size, RZ, /*is_zeroed*/1 ); 48 return (void*)p; 49 } 50 51 static void custom_free(void* p) 52 { 53 // don't actually free any memory... but mark it as freed 54 VALGRIND_FREELIKE_BLOCK( p, RZ ); 55 } 56 57 static void checkredzone(void) 58 { 59 /* check that accessing the redzone of a MALLOCLIKE block 60 is detected when the superblock was not marked as no access. */ 61 char superblock[1 + RZ + 20 + RZ + 1]; 62 char *p = 1 + RZ + superblock; 63 assert(RZ > 0); 64 65 // Indicate we have allocated p from our superblock: 66 VALGRIND_MALLOCLIKE_BLOCK( p, 20, RZ, /*is_zeroed*/1 ); 67 p[0] = 0; 68 p[-1] = p[0]; // error expected 69 p[-RZ] = p[0]; // error expected 70 p[-RZ-1] = p[0]; // no error expected 71 72 p[19] = 0; 73 p[19 + 1] = p[0]; // error expected 74 p[19 + RZ] = p[0]; // error expected 75 p[19 + RZ + 1] = p[0]; // no error expected 76 77 VALGRIND_FREELIKE_BLOCK( p, RZ ); 78 79 // Now, indicate we have re-allocated p from our superblock 80 // but with only a size 10. 81 VALGRIND_MALLOCLIKE_BLOCK( p, 10, RZ, /*is_zeroed*/1 ); 82 p[0] = 0; 83 p[-1] = p[0]; // error expected 84 p[-RZ] = p[0]; // error expected 85 p[-RZ-1] = p[0]; // no error expected 86 87 p[9] = 0; 88 p[9 + 1] = p[0]; // error expected 89 p[9 + RZ] = p[0]; // error expected 90 p[9 + RZ + 1] = p[0]; // no error expected 91 92 VALGRIND_FREELIKE_BLOCK( p, RZ ); 93 94 } 95 96 97 98 //------------------------------------------------------------------------- 99 // Rest 100 //------------------------------------------------------------------------- 101 102 void make_leak(void) 103 { 104 int* array2 __attribute__((unused)) = custom_alloc(sizeof(int) * 10); 105 array2 = 0; // leak 106 return; 107 } 108 109 int main(void) 110 { 111 int *array, *array3; 112 int x; 113 114 array = custom_alloc(sizeof(int) * 10); 115 array[8] = 8; 116 array[9] = 8; 117 array[10] = 10; // invalid write (ok w/o MALLOCLIKE -- in superblock) 118 119 VALGRIND_RESIZEINPLACE_BLOCK(array, sizeof(int) * 10, sizeof(int) * 5, RZ); 120 array[4] = 7; 121 array[5] = 9; // invalid write 122 123 // Make the entire array defined again such that it can be verified whether 124 // the red zone is marked properly when resizing in place. 125 VALGRIND_MAKE_MEM_DEFINED(array, sizeof(int) * 10); 126 127 VALGRIND_RESIZEINPLACE_BLOCK(array, sizeof(int) * 5, sizeof(int) * 7, RZ); 128 if (array[5]) array[4]++; // uninitialized read of array[5] 129 array[5] = 11; 130 array[6] = 7; 131 array[7] = 8; // invalid write 132 133 // invalid realloc 134 VALGRIND_RESIZEINPLACE_BLOCK(array+1, sizeof(int) * 7, sizeof(int) * 8, RZ); 135 136 custom_free(array); // ok 137 138 custom_free((void*)0x1); // invalid free 139 140 array3 = malloc(sizeof(int) * 10); 141 custom_free(array3); // mismatched free (ok without MALLOCLIKE) 142 143 make_leak(); 144 x = array[0]; // use after free (ok without MALLOCLIKE/MAKE_MEM_NOACCESS) 145 146 // Bug 137073: passing 0 to MALLOCLIKE_BLOCK was causing an assertion 147 // failure. Test for this (and likewise for FREELIKE_BLOCK). 148 VALGRIND_MALLOCLIKE_BLOCK(0,0,0,0); 149 VALGRIND_FREELIKE_BLOCK(0,0); 150 151 checkredzone(); 152 153 return x; 154 155 // leak from make_leak() 156 } 157 158 #undef RZ 159
