1 #include "tests/malloc.h" 2 #include <stdio.h> 3 #include <assert.h> 4 5 typedef unsigned long long int ULong; 6 typedef unsigned long int UWord; 7 8 __attribute__((noinline)) my_ffsll(ULong x)9static int my_ffsll ( ULong x ) 10 { 11 int i; 12 for (i = 0; i < 64; i++) { 13 if ((x & 1ULL) == 1ULL) 14 break; 15 x >>= 1; 16 } 17 return i+1; 18 } 19 20 /* Find length of string, assuming it is aligned and shorter than 8 21 characters. Little-endian only. */ 22 __attribute__((noinline)) aligned_strlen(char * s)23static int aligned_strlen(char *s) 24 { 25 /* This is for 64-bit platforms */ 26 assert(sizeof(ULong) == 8); 27 /* ..and only works for aligned input */ 28 assert(((unsigned long)s & 0x7) == 0); 29 30 /* read 8 bytes */ 31 ULong val = *(ULong*)s; 32 /* Subtract one from each byte */ 33 ULong val2 = val - 0x0101010101010101ULL; 34 /* Find lowest byte whose high bit changed */ 35 val2 ^= val; 36 val2 &= 0x8080808080808080ULL; 37 38 return (my_ffsll(val2) / 8) - 1; 39 } 40 foo(int x)41__attribute__((noinline)) void foo ( int x ) 42 { 43 __asm__ __volatile__("":::"memory"); 44 } 45 46 int main(int argc,char * argv[])47main(int argc, char *argv[]) 48 { 49 char *buf = memalign16(5); 50 buf[0] = 'a'; 51 buf[1] = 'b'; 52 buf[2] = 'c'; 53 buf[3] = 'd'; 54 buf[4] = '\0'; 55 56 /* --partial-loads-ok=no: expect addr error (here) */ 57 /* --partial-loads-ok=yes: expect no error */ 58 if (aligned_strlen(buf) == 4) 59 foo(44); 60 61 /* --partial-loads-ok=no: expect addr error (here) */ 62 /* --partial-loads-ok=yes: expect value error (in my_ffsll) */ 63 buf[4] = 'x'; 64 if (aligned_strlen(buf) == 0) 65 foo(37); 66 67 free(buf); 68 69 /* Also, we need to check that a completely out-of-range, 70 word-sized load gives an addressing error regardless of the 71 start of --partial-loads-ok=. *And* that the resulting 72 value is completely defined. */ 73 UWord* words = malloc(3 * sizeof(UWord)); 74 free(words); 75 76 /* Should ALWAYS give an addr error. */ 77 UWord w = words[1]; 78 79 /* Should NEVER give an error (you might expect a value one, but no.) */ 80 if (w == 0x31415927) { 81 fprintf(stderr, 82 "Elvis is alive and well and living in Milton Keynes.\n"); 83 } 84 85 return 0; 86 } 87