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Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H . J . Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V . Shankar" , Dave Martin , Weijiang Yang , "Kirill A . Shutemov" , joao.moreira@intel.com, John Allen , kcc@google.com, eranian@google.com, Andrei Vagin , Dmitry Safonov <0x7f454c46@gmail.com> Subject: Re: [PATCH 00/35] Shadow stacks for userspace Message-ID: References: <20220130211838.8382-1-rick.p.edgecombe@intel.com> <8f96c2a6-9c03-f97a-df52-73ffc1d87957@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.0.7 (2021-05-04) X-Rspamd-Server: rspam11 X-Rspam-User: X-Stat-Signature: cff77rffeadmyxts3ftspkyufzrsujxa Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=Cxuiov0o; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf01.hostedemail.com: domain of gorcunov@gmail.com designates 209.85.208.180 as permitted sender) smtp.mailfrom=gorcunov@gmail.com X-Rspamd-Queue-Id: 399E640007 X-HE-Tag: 1644312562-735463 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 Tue, Feb 08, 2022 at 11:16:51AM +0200, Mike Rapoport wrote: > > > Any thoughts on how you would _like_ to see this resolved? > > Ideally, CRIU will need a knob that will tell the kernel/CET machinery > where the next RET will jump, along the lines of > restore_signal_shadow_stack() AFAIU. > > But such a knob will immediately reduce the security value of the entire > thing, and I don't have good ideas how to deal with it :( Probably a kind of latch in the task_struct which would trigger off once returt to a different address happened, thus we would be able to jump inside paratite code. Of course such trigger should be available under proper capability only.