From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu-cheng Yu Subject: Re: [PATCH v7 22/27] binfmt_elf: Extract .note.gnu.property from an ELF file Date: Tue, 18 Jun 2019 09:00:35 -0700 Message-ID: References: <87lfy9cq04.fsf@oldenburg2.str.redhat.com> <20190611114109.GN28398@e103592.cambridge.arm.com> <031bc55d8dcdcf4f031e6ff27c33fd52c61d33a5.camel@intel.com> <20190612093238.GQ28398@e103592.cambridge.arm.com> <87imt4jwpt.fsf@oldenburg2.str.redhat.com> <20190618091248.GB2790@e103592.cambridge.arm.com> <20190618124122.GH3419@hirez.programming.kicks-ass.net> <87ef3r9i2j.fsf@oldenburg2.str.redhat.com> <20190618125512.GJ3419@hirez.programming.kicks-ass.net> <20190618133223.GD2790@e103592.cambridge.arm.com> <87pnna7v1d.fsf@oldenburg2.str.redhat.com> <1ca57aaae8a2121731f2dcb1a137b92eed39a0d2.camel@intel.com> <87blyu7ubf.fsf@oldenburg2.str.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <87blyu7ubf.fsf@oldenburg2.str.redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Florian Weimer Cc: Dave Martin , Peter Zijlstra , Thomas Gleixner , x86@kernel.org, "H. Peter Anvin" , 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 , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , N List-Id: linux-arch.vger.kernel.org On Tue, 2019-06-18 at 18:05 +0200, Florian Weimer wrote: > * Yu-cheng Yu: > > > > I assumed that it would also parse the main executable and make > > > adjustments based on that. > > > > Yes, Linux also looks at the main executable's header, but not its > > NT_GNU_PROPERTY_TYPE_0 if there is a loader. > > > > > > > > ld.so can certainly provide whatever the kernel needs. We need to tweak > > > the existing loader anyway. > > > > > > No valid statically-linked binaries exist today, so this is not a > > > consideration at this point. > > > > So from kernel, we look at only PT_GNU_PROPERTY? > > If you don't parse notes/segments in the executable for CET, then yes. > We can put PT_GNU_PROPERTY into the loader. Thanks! From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga03.intel.com ([134.134.136.65]:12038 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729247AbfFRQIp (ORCPT ); Tue, 18 Jun 2019 12:08:45 -0400 Message-ID: Subject: Re: [PATCH v7 22/27] binfmt_elf: Extract .note.gnu.property from an ELF file From: Yu-cheng Yu Date: Tue, 18 Jun 2019 09:00:35 -0700 In-Reply-To: <87blyu7ubf.fsf@oldenburg2.str.redhat.com> References: <87lfy9cq04.fsf@oldenburg2.str.redhat.com> <20190611114109.GN28398@e103592.cambridge.arm.com> <031bc55d8dcdcf4f031e6ff27c33fd52c61d33a5.camel@intel.com> <20190612093238.GQ28398@e103592.cambridge.arm.com> <87imt4jwpt.fsf@oldenburg2.str.redhat.com> <20190618091248.GB2790@e103592.cambridge.arm.com> <20190618124122.GH3419@hirez.programming.kicks-ass.net> <87ef3r9i2j.fsf@oldenburg2.str.redhat.com> <20190618125512.GJ3419@hirez.programming.kicks-ass.net> <20190618133223.GD2790@e103592.cambridge.arm.com> <87pnna7v1d.fsf@oldenburg2.str.redhat.com> <1ca57aaae8a2121731f2dcb1a137b92eed39a0d2.camel@intel.com> <87blyu7ubf.fsf@oldenburg2.str.redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Florian Weimer Cc: Dave Martin , Peter Zijlstra , Thomas Gleixner , x86@kernel.org, "H. Peter Anvin" , 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 , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue Message-ID: <20190618160035.IYDxw8APt_0WaqO7_tkH8Ou9d2D7ZTqPnSlJqy9cnCo@z> On Tue, 2019-06-18 at 18:05 +0200, Florian Weimer wrote: > * Yu-cheng Yu: > > > > I assumed that it would also parse the main executable and make > > > adjustments based on that. > > > > Yes, Linux also looks at the main executable's header, but not its > > NT_GNU_PROPERTY_TYPE_0 if there is a loader. > > > > > > > > ld.so can certainly provide whatever the kernel needs. We need to tweak > > > the existing loader anyway. > > > > > > No valid statically-linked binaries exist today, so this is not a > > > consideration at this point. > > > > So from kernel, we look at only PT_GNU_PROPERTY? > > If you don't parse notes/segments in the executable for CET, then yes. > We can put PT_GNU_PROPERTY into the loader. Thanks!