On Thu, Nov 19, 2020 at 8:04 PM Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > > On Wed, Nov 18, 2020 at 02:07:14PM -0800, Sami Tolvanen wrote: > > This patch series adds support for building the kernel with Clang's > > Link Time Optimization (LTO). In addition to performance, the primary > > motivation for LTO is to allow Clang's Control-Flow Integrity (CFI) to > > be used in the kernel. Google has shipped millions of Pixel devices > > running three major kernel versions with LTO+CFI since 2018. > > > > Most of the patches are build system changes for handling LLVM bitcode, > > which Clang produces with LTO instead of ELF object files, postponing > > ELF processing until a later stage, and ensuring initcall ordering. > > > > Note that v7 brings back arm64 support as Will has now staged the > > prerequisite memory ordering patches [1], and drops x86_64 while we work > > on fixing the remaining objtool warnings [2]. > > Sami, > > Here are some patches to fix the objtool issues (other than crypto which > I'll work on next). > > https://git.kernel.org/pub/scm/linux/kernel/git/jpoimboe/linux.git objtool-vmlinux Thanks, Josh! I can confirm that these fix all the non-crypto objtool warnings with LTO as well. Sami
