From mboxrd@z Thu Jan 1 00:00:00 1970 From: peterz@infradead.org (Peter Zijlstra) Date: Fri, 13 May 2011 14:39:30 +0200 Subject: [PATCH 3/5] v2 seccomp_filters: Enable ftrace-based system call filtering In-Reply-To: <20110513122646.GA3924@elte.hu> References: <1304017638.18763.205.camel@gandalf.stny.rr.com> <1305169376-2363-1-git-send-email-wad@chromium.org> <20110512074850.GA9937@elte.hu> <20110512130104.GA2912@elte.hu> <20110513121034.GG21022@elte.hu> <1305289146.2466.8.camel@twins> <20110513122646.GA3924@elte.hu> Message-ID: <1305290370.2466.14.camel@twins> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 2011-05-13 at 14:26 +0200, Ingo Molnar wrote: > * Peter Zijlstra wrote: > > > On Fri, 2011-05-13 at 14:10 +0200, Ingo Molnar wrote: > > > err = event_vfs_getname(result); > > > > I really think we should not do this. Events like we have them should be > > inactive, totally passive entities, only observe but not affect execution > > (other than the bare minimal time delay introduced by observance). > > Well, this patchset already demonstrates that we can use a single event > callback for a rather useful purpose. Can and should are two distinct things. > Either it makes sense to do, in which case we should share facilities as much > as possible, or it makes no sense, in which case we should not merge it at all. And I'm arguing we should _not_. Observing is radically different from Affecting, at the very least the two things should have different permission schemes. We should not confuse these two matters. > > If you want another entity that is more active, please invent a new name for > > it and create a new subsystem for them, now you could have these active > > entities also have an (automatic) passive event side, but that's some detail. > > Why should we have two callbacks next to each other: > > event_vfs_getname(result); > result = check_event_vfs_getname(result); > > if one could do it all? Did you actually read the bit where I said that check_event_* (although I still think that name sucks) could imply a matching event_*?