From mboxrd@z Thu Jan 1 00:00:00 1970 Reply-To: kernel-hardening@lists.openwall.com From: "PaX Team" Date: Sun, 29 Nov 2015 12:15:01 +0100 MIME-Version: 1.0 Message-ID: <565ADE35.20892.225C67C2@pageexec.freemail.hu> In-reply-to: <20151129080853.GB23721@gmail.com> References: <1448401114-24650-1-git-send-email-keescook@chromium.org>, <565876F3.21515.18F8DF8F@pageexec.freemail.hu>, <20151129080853.GB23721@gmail.com> Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Content-description: Mail message body Subject: Re: [kernel-hardening] [PATCH 0/2] introduce post-init read-only memory To: Ingo Molnar Cc: Linus Torvalds , kernel-hardening@lists.openwall.com, Mathias Krause , "linux-kernel@vger.kernel.org" , Kees Cook , Andy Lutomirski , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , x86-ml , Arnd Bergmann , Michael Ellerman , linux-arch@vger.kernel.org, Emese Revfy List-ID: On 29 Nov 2015 at 9:08, Ingo Molnar wrote: > > * PaX Team wrote: > > > i don't see the compile time vs. runtime detection as 'competing' approaches, > > both have their own role. [...] > > That's true - but only as long as 'this can be solved in tooling!' is not used as > an excuse to oppose the runtime solution and we end up doing neither. actually, i already voiced my opinion elsewhere in the constify thread on the kernel hardening list that adding/using __read_only is somewhat premature without also adding the compile time verification part (as part of the constify plugin for example). right now its use on the embedded vdso image is simple and easy to verify but once people begin to add it to variables that the compiler knows and cares about (say, the ops structures) then things can become fragile without compile checking. so yes, i'd also advise to get such tooling in *before* more __read_only usage is added. From mboxrd@z Thu Jan 1 00:00:00 1970 From: "PaX Team" Subject: Re: [PATCH 0/2] introduce post-init read-only memory Date: Sun, 29 Nov 2015 12:15:01 +0100 Message-ID: <565ADE35.20892.225C67C2@pageexec.freemail.hu> References: <1448401114-24650-1-git-send-email-keescook@chromium.org>, <565876F3.21515.18F8DF8F@pageexec.freemail.hu>, <20151129080853.GB23721@gmail.com> Reply-To: kernel-hardening@lists.openwall.com Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: List-Post: List-Help: List-Unsubscribe: List-Subscribe: In-reply-to: <20151129080853.GB23721@gmail.com> Content-description: Mail message body To: Ingo Molnar Cc: Linus Torvalds , kernel-hardening@lists.openwall.com, Mathias Krause , "linux-kernel@vger.kernel.org" , Kees Cook , Andy Lutomirski , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , x86-ml , Arnd Bergmann , Michael Ellerman , linux-arch@vger.kernel.org, Emese Revfy List-Id: linux-arch.vger.kernel.org On 29 Nov 2015 at 9:08, Ingo Molnar wrote: > > * PaX Team wrote: > > > i don't see the compile time vs. runtime detection as 'competing' approaches, > > both have their own role. [...] > > That's true - but only as long as 'this can be solved in tooling!' is not used as > an excuse to oppose the runtime solution and we end up doing neither. actually, i already voiced my opinion elsewhere in the constify thread on the kernel hardening list that adding/using __read_only is somewhat premature without also adding the compile time verification part (as part of the constify plugin for example). right now its use on the embedded vdso image is simple and easy to verify but once people begin to add it to variables that the compiler knows and cares about (say, the ops structures) then things can become fragile without compile checking. so yes, i'd also advise to get such tooling in *before* more __read_only usage is added.