From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lyndon Nerenberg To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> In-reply-to: References: <20181009001435.B6DDA156E40C@mail.bitblocks.com> <7aa1f60316858415@orthanc.ca> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <60800.1539112980.1@orthanc.ca> Date: Tue, 9 Oct 2018 12:23:00 -0700 Message-Id: <7aa1f6be487cb771@orthanc.ca> Cc: Lyndon Nerenberg Subject: Re: [9fans] PDP11 (Was: Re: what heavy negativity!) Topicbox-Message-UUID: e984f4c4-ead9-11e9-9d60-3106f5b1d025 hiro writes: > > Dealing with the security issues isn't trivial > what security issues? Passing protocol buffer like objects around user space, that might affect how the kernel talks to hardware. E.g. IPsec offload into hardware. You don't want user-space messing with that sort of context, but you want to tag it with the data buffer as it gets passed up and down through the user/kernel gate. Practical page flipping needs a kernel-read-only context attached to the non-kernel user data part of the page. A quick solution is to pair pages, one half of which the kernel owns, the other being the data payload. But that't just a start. And that's all I'm saying: this might be an approach to a better/faster I/O paradigm, but it needs interested people to explore it ... --lyndon