1 2 /* Check basic stack overflow detection. 3 4 It's difficult to get consistent behaviour across all platforms. 5 For example, x86 w/ gcc-4.3.1 gives 6 7 Expected: stack array "a" in frame 2 back from here 8 Actual: stack array "beforea" in frame 2 back from here 9 10 whereas amd64 w/ gcc-4.3.1 gives 11 12 Expected: stack array "a" in frame 2 back from here 13 Actual: unknown 14 15 This happens because on x86 the arrays are placed on the 16 stack without holes in between, but not so for amd64. I don't 17 know why. 18 */ 19 20 21 #include <stdio.h> 22 23 __attribute__((noinline)) void foo ( long* sa, int n ) 24 { 25 int i; 26 for (i = 0; i < n; i++) 27 sa[i] = 0; 28 } 29 30 __attribute__((noinline)) void bar ( long* sa, int n ) 31 { 32 foo(sa, n); 33 } 34 35 int main ( void ) 36 { 37 int i; 38 long beforea[3]; 39 long a[7]; 40 long aftera[3]; 41 bar(a, 7+1); /* generates error */ 42 bar(a, 7+0); /* generates no error */ 43 for (i = 0; i < 7+1; i++) { 44 a[i] = 0; 45 } 46 {char beforebuf[8]; 47 char buf[8]; 48 char afterbuf[8]; 49 sprintf(buf, "%d", 123456789); 50 return 1 & ((a[4] + beforea[1] + aftera[1] + beforebuf[1] 51 + buf[2] + afterbuf[3]) / 100000) ; 52 } 53 } 54
