| #include <assert.h> |
| |
| static int x; |
| |
| int main() |
| { |
| int *p0 = &x, *p1, *p2, *p3; |
| unsigned long salt = 0; |
| |
| /* |
| * With TBI enabled and a 48-bit VA, there are 7 bits of auth, and so |
| * a 1/128 chance of auth = pac(ptr,key,salt) producing zero. |
| * Find a salt that creates auth != 0. |
| */ |
| do { |
| salt++; |
| asm("pacda %0, %1" : "=r"(p1) : "r"(salt), "0"(p0)); |
| } while (p0 == p1); |
| |
| /* |
| * This pac must fail, because the input pointer bears an encryption, |
| * and so is not properly extended within bits [55:47]. This will |
| * toggle bit 54 in the output... |
| */ |
| asm("pacda %0, %1" : "=r"(p2) : "r"(salt), "0"(p1)); |
| |
| /* ... so that the aut must fail, setting bit 53 in the output ... */ |
| asm("autda %0, %1" : "=r"(p3) : "r"(salt), "0"(p2)); |
| |
| /* ... which means this equality must not hold. */ |
| assert(p3 != p0); |
| return 0; |
| } |
