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Hallyn" , Kees Cook Subject: Re: pidfd design Message-ID: <20190320191935.GB76715@google.com> References: <20190319231020.tdcttojlbmx57gke@brauner.io> <20190320015249.GC129907@google.com> <20190320035953.mnhax3vd47ya4zzm@brauner.io> <4A06C5BB-9171-4E70-BE31-9574B4083A9F@joelfernandes.org> <20190320182649.spryp5uaeiaxijum@brauner.io> <20190320185156.7bq775vvtsxqlzfn@brauner.io> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190320185156.7bq775vvtsxqlzfn@brauner.io> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Mar 20, 2019 at 07:51:57PM +0100, Christian Brauner wrote: [snip] > > > translate_pid() should just return you a pidfd. Having it return a pidfd > > > and a status fd feels like stuffing too much functionality in there. If > > > you're fine with it I'll finish prototyping what I had in mind. As I > > > said in previous mails I'm already working on this. > > > > translate_pid also needs to *accept* pidfds, at least optionally. > > Unless you have a function from pidfd to pidfd, you race. > > You're misunderstanding. Again, I said in my previous mails it should > accept pidfds optionally as arguments, yes. But I don't want it to > return the status fds that you previously wanted pidfd_wait() to return. > I really want to see Joel's pidfd_wait() patchset and have more people > review the actual code. No problem, pidfd_wait is also fine with me and we can change it later to translate_pid or something else if needed. Agreed that lets get to some code writing now that (I hope) we are all on the same page and discuss on actual code. - Joel