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
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