xor as a lazy comparison

From: Jan Engelhardt
Date: Sun Jul 24 2005 - 11:41:56 EST

Hi list,

I have seen this in kernel/signal.c:check_kill_permission()

&& (current->euid ^ t->suid) && (current->euid ^ t->uid)

If current->euid and t->suid are the same, the xor returns 0, so these
statements are effectively the same as a !=

current->euid != t->suid ...

Why ^ ?

Jan Engelhardt
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/