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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id n2sm3182853pja.41.2020.09.30.14.10.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Sep 2020 14:10:34 -0700 (PDT) Date: Wed, 30 Sep 2020 14:10:33 -0700 From: Kees Cook To: Peter Zijlstra , Steven Rostedt Cc: Sami Tolvanen , Masahiro Yamada , Will Deacon , Greg Kroah-Hartman , "Paul E. McKenney" , Nick Desaulniers , clang-built-linux@googlegroups.com, kernel-hardening@lists.openwall.com, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v4 00/29] Add support for Clang LTO Message-ID: <202009301402.27A40DD1@keescook> References: <20200929214631.3516445-1-samitolvanen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200929214631.3516445-1-samitolvanen@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org On Tue, Sep 29, 2020 at 02:46:02PM -0700, Sami Tolvanen wrote: > Furthermore, patches 4-8 include Peter's patch for generating > __mcount_loc with objtool, and build system changes to enable it on > x86. With these patches, we no longer need to annotate functions > that have non-call references to __fentry__ with LTO, which makes > supporting dynamic ftrace much simpler. Peter, can you take patches 4-8 into -tip? I think it'd make sense to keep them together. Steven, it sounds like you're okay with the changes (i.e. Sami showed the one concern you had was already handled)? Getting these into v5.10 would be really really nice. I'd really like to get the tree-spanning prerequisites nailed down for this series. It's been difficult to coordinate given the multiple maintainers. :) Specifically these patches: Peter Zijlstra (1): objtool: Add a pass for generating __mcount_loc Sami Tolvanen (4): objtool: Don't autodetect vmlinux.o tracing: move function tracer options to Kconfig tracing: add support for objtool mcount x86, build: use objtool mcount https://lore.kernel.org/lkml/20200929214631.3516445-5-samitolvanen@google.com/ https://lore.kernel.org/lkml/20200929214631.3516445-6-samitolvanen@google.com/ https://lore.kernel.org/lkml/20200929214631.3516445-7-samitolvanen@google.com/ https://lore.kernel.org/lkml/20200929214631.3516445-8-samitolvanen@google.com/ https://lore.kernel.org/lkml/20200929214631.3516445-9-samitolvanen@google.com/ Thanks! -- Kees Cook