| #include <assert.h> |
| #include <stdio.h> |
| #include <sys/syscall.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| // kernel brk() and libc brk() act quite differently... |
| |
| int main(void) |
| { |
| int i; |
| void* orig_ds = sbrk(0); |
| void* ds = orig_ds; |
| void* vals[10]; |
| void* res; |
| #define EOL ((void*)( ~(long)0 )) |
| vals[0] = (void*)0; |
| vals[1] = (void*)1; |
| vals[2] = ds - 0x1; // small shrink |
| vals[3] = ds; |
| vals[4] = ds + 0x1000; // small growth |
| vals[5] = ds + 0x40000000; // too-big growth |
| vals[6] = ds + 0x500; // shrink a little, but still above start size |
| vals[7] = ds - 0x1; // shrink below start size |
| // vals[8] = ds - 0x1000; // shrink a lot below start size (into text) |
| // vals[9] = EOL; |
| vals[8] = EOL; |
| |
| for (i = 0; EOL != vals[i]; i++) { |
| res = (void*)syscall(__NR_brk, vals[i]); |
| } |
| |
| assert( 0 == brk(orig_ds) ); // libc brk() |
| |
| for (i = 0; EOL != vals[i]; i++) { |
| res = (void*)brk(vals[i]); |
| } |
| |
| return 0; |
| } |