From: Masahiro Yamada <masahiroy@kernel.org> To: Sami Tolvanen <samitolvanen@google.com> Cc: Will Deacon <will@kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, "Paul E. McKenney" <paulmck@kernel.org>, Kees Cook <keescook@chromium.org>, Nick Desaulniers <ndesaulniers@google.com>, clang-built-linux <clang-built-linux@googlegroups.com>, Kernel Hardening <kernel-hardening@lists.openwall.com>, linux-arch <linux-arch@vger.kernel.org>, linux-arm-kernel <linux-arm-kernel@lists.infradead.org>, Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, linux-pci@vger.kernel.org, X86 ML <x86@kernel.org> Subject: Re: [PATCH 00/22] add support for Clang LTO Date: Mon, 29 Jun 2020 01:56:19 +0900 Message-ID: <CAK7LNASvb0UDJ0U5wkYYRzTAdnEs64HjXpEUL7d=V0CXiAXcNw@mail.gmail.com> (raw) In-Reply-To: <20200624203200.78870-1-samitolvanen@google.com> On Thu, Jun 25, 2020 at 5:32 AM 'Sami Tolvanen' via Clang Built Linux <clang-built-linux@googlegroups.com> wrote: > > This patch series adds support for building x86_64 and arm64 kernels > 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's > Pixel devices have shipped with LTO+CFI kernels 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 first objtool patch in the series is already in linux-next, > but as it's needed with LTO, I'm including it also here to make testing > easier. I put this series on a testing branch, and 0-day bot started reporting some issues. (but 0-day bot is quieter than I expected. Perhaps, 0-day bot does not turn on LLVM=1 ?) I also got an error for ARCH=arm64 allyesconfig + CONFIG_LTO_CLANG=y $ make ARCH=arm64 LLVM=1 LLVM_IAS=1 CROSS_COMPILE=~/tools/aarch64-linaro-7.5/bin/aarch64-linux-gnu- -j24 ... GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o AR init/built-in.a GEN .tmp_initcalls.lds GEN .tmp_symversions.lds LTO vmlinux.o MODPOST vmlinux.symvers MODINFO modules.builtin.modinfo GEN modules.builtin LD .tmp_vmlinux.kallsyms1 ld.lld: error: undefined symbol: __compiletime_assert_905 >>> referenced by irqbypass.c >>> vmlinux.o:(jeq_imm) make: *** [Makefile:1161: vmlinux] Error 1 > Sami Tolvanen (22): > objtool: use sh_info to find the base for .rela sections > kbuild: add support for Clang LTO > kbuild: lto: fix module versioning > kbuild: lto: fix recordmcount > kbuild: lto: postpone objtool > kbuild: lto: limit inlining > kbuild: lto: merge module sections > kbuild: lto: remove duplicate dependencies from .mod files > init: lto: ensure initcall ordering > init: lto: fix PREL32 relocations > pci: lto: fix PREL32 relocations > modpost: lto: strip .lto from module names > scripts/mod: disable LTO for empty.c > efi/libstub: disable LTO > drivers/misc/lkdtm: disable LTO for rodata.o > arm64: export CC_USING_PATCHABLE_FUNCTION_ENTRY > arm64: vdso: disable LTO > arm64: allow LTO_CLANG and THINLTO to be selected > x86, vdso: disable LTO only for vDSO > x86, ftrace: disable recordmcount for ftrace_make_nop > x86, relocs: Ignore L4_PAGE_OFFSET relocations > x86, build: allow LTO_CLANG and THINLTO to be selected > > .gitignore | 1 + > Makefile | 27 ++- > arch/Kconfig | 65 +++++++ > arch/arm64/Kconfig | 2 + > arch/arm64/Makefile | 1 + > arch/arm64/kernel/vdso/Makefile | 4 +- > arch/x86/Kconfig | 2 + > arch/x86/Makefile | 5 + > arch/x86/entry/vdso/Makefile | 5 +- > arch/x86/kernel/ftrace.c | 1 + > arch/x86/tools/relocs.c | 1 + > drivers/firmware/efi/libstub/Makefile | 2 + > drivers/misc/lkdtm/Makefile | 1 + > include/asm-generic/vmlinux.lds.h | 12 +- > include/linux/compiler-clang.h | 4 + > include/linux/compiler.h | 2 +- > include/linux/compiler_types.h | 4 + > include/linux/init.h | 78 +++++++- > include/linux/pci.h | 15 +- > kernel/trace/ftrace.c | 1 + > lib/Kconfig.debug | 2 +- > scripts/Makefile.build | 55 +++++- > scripts/Makefile.lib | 6 +- > scripts/Makefile.modfinal | 40 +++- > scripts/Makefile.modpost | 26 ++- > scripts/generate_initcall_order.pl | 270 ++++++++++++++++++++++++++ > scripts/link-vmlinux.sh | 100 +++++++++- > scripts/mod/Makefile | 1 + > scripts/mod/modpost.c | 16 +- > scripts/mod/modpost.h | 9 + > scripts/mod/sumversion.c | 6 +- > scripts/module-lto.lds | 26 +++ > scripts/recordmcount.c | 3 +- > tools/objtool/elf.c | 2 +- > 34 files changed, 737 insertions(+), 58 deletions(-) > create mode 100755 scripts/generate_initcall_order.pl > create mode 100644 scripts/module-lto.lds > > > base-commit: 26e122e97a3d0390ebec389347f64f3730fdf48f > -- > 2.27.0.212.ge8ba1cc988-goog > > -- > You received this message because you are subscribed to the Google Groups "Clang Built Linux" group. > To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20200624203200.78870-1-samitolvanen%40google.com. -- Best Regards Masahiro Yamada
next prev parent reply index Thread overview: 213+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-06-24 20:31 Sami Tolvanen 2020-06-24 20:31 ` [PATCH 01/22] objtool: use sh_info to find the base for .rela sections Sami Tolvanen 2020-06-24 20:31 ` [PATCH 02/22] kbuild: add support for Clang LTO Sami Tolvanen 2020-06-24 20:53 ` Nick Desaulniers 2020-06-24 21:29 ` Sami Tolvanen 2020-06-25 2:26 ` Nathan Chancellor 2020-06-25 16:13 ` Sami Tolvanen 2020-06-24 20:31 ` [PATCH 03/22] kbuild: lto: fix module versioning Sami Tolvanen 2020-06-24 20:31 ` [PATCH 04/22] kbuild: lto: fix recordmcount Sami Tolvanen 2020-06-24 21:27 ` Peter Zijlstra 2020-06-24 21:45 ` Sami Tolvanen 2020-06-25 7:45 ` Peter Zijlstra 2020-06-25 16:15 ` Sami Tolvanen 2020-06-25 20:02 ` [RFC][PATCH] objtool,x86_64: Replace recordmcount with objtool Peter Zijlstra 2020-06-25 20:54 ` Nick Desaulniers 2020-06-25 22:40 ` Sami Tolvanen 2020-06-26 11:29 ` Peter Zijlstra 2020-06-26 11:42 ` Peter Zijlstra 2020-07-17 17:28 ` Sami Tolvanen 2020-07-17 17:36 ` Steven Rostedt 2020-07-17 17:47 ` Sami Tolvanen 2020-07-17 18:05 ` Steven Rostedt 2020-07-20 16:52 ` Sami Tolvanen 2020-07-22 17:58 ` Steven Rostedt 2020-07-22 18:07 ` Sami Tolvanen 2020-07-22 17:55 ` Steven Rostedt 2020-07-22 18:41 ` Peter Zijlstra 2020-07-22 19:09 ` Steven Rostedt 2020-07-22 20:03 ` Sami Tolvanen 2020-07-22 23:56 ` Peter Zijlstra 2020-07-23 0:06 ` Steven Rostedt 2020-08-06 22:09 ` Sami Tolvanen 2020-06-24 20:31 ` [PATCH 05/22] kbuild: lto: postpone objtool Sami Tolvanen 2020-06-24 21:19 ` Peter Zijlstra 2020-06-24 21:49 ` Sami Tolvanen 2020-06-25 7:47 ` Peter Zijlstra 2020-06-25 16:22 ` Sami Tolvanen 2020-06-25 18:33 ` Peter Zijlstra 2020-06-25 19:32 ` Sami Tolvanen 2020-06-24 20:31 ` [PATCH 06/22] kbuild: lto: limit inlining Sami Tolvanen 2020-06-24 21:20 ` Peter Zijlstra 2020-06-24 23:37 ` Sami Tolvanen 2020-06-24 20:31 ` [PATCH 07/22] kbuild: lto: merge module sections Sami Tolvanen 2020-06-24 21:01 ` Nick Desaulniers 2020-06-24 21:31 ` Sami Tolvanen 2020-06-24 20:31 ` [PATCH 08/22] kbuild: lto: remove duplicate dependencies from .mod files Sami Tolvanen 2020-06-24 21:13 ` Nick Desaulniers 2020-06-24 20:31 ` [PATCH 09/22] init: lto: ensure initcall ordering Sami Tolvanen 2020-06-25 0:58 ` kernel test robot 2020-06-25 4:19 ` kernel test robot 2020-06-24 20:31 ` [PATCH 10/22] init: lto: fix PREL32 relocations Sami Tolvanen 2020-06-24 20:31 ` [PATCH 11/22] pci: " Sami Tolvanen 2020-06-24 22:49 ` kernel test robot 2020-06-24 23:03 ` Nick Desaulniers 2020-06-24 23:21 ` Sami Tolvanen 2020-07-17 20:26 ` Bjorn Helgaas 2020-07-22 18:15 ` Sami Tolvanen 2020-06-24 20:31 ` [PATCH 12/22] modpost: lto: strip .lto from module names Sami Tolvanen 2020-06-24 22:05 ` Nick Desaulniers 2020-06-24 20:31 ` [PATCH 13/22] scripts/mod: disable LTO for empty.c Sami Tolvanen 2020-06-24 20:57 ` Nick Desaulniers 2020-06-24 20:31 ` [PATCH 14/22] efi/libstub: disable LTO Sami Tolvanen 2020-06-24 20:31 ` [PATCH 15/22] drivers/misc/lkdtm: disable LTO for rodata.o Sami Tolvanen 2020-06-24 20:31 ` [PATCH 16/22] arm64: export CC_USING_PATCHABLE_FUNCTION_ENTRY Sami Tolvanen 2020-06-24 20:31 ` [PATCH 17/22] arm64: vdso: disable LTO Sami Tolvanen 2020-06-24 20:58 ` Nick Desaulniers 2020-06-24 21:09 ` Nick Desaulniers 2020-06-24 23:51 ` Andi Kleen 2020-06-24 21:52 ` Sami Tolvanen 2020-06-24 23:05 ` Nick Desaulniers 2020-06-24 23:39 ` Sami Tolvanen 2020-06-24 20:31 ` [PATCH 18/22] arm64: allow LTO_CLANG and THINLTO to be selected Sami Tolvanen 2020-06-24 20:31 ` [PATCH 19/22] x86, vdso: disable LTO only for vDSO Sami Tolvanen 2020-06-24 20:31 ` [PATCH 20/22] x86, ftrace: disable recordmcount for ftrace_make_nop Sami Tolvanen 2020-06-24 20:31 ` [PATCH 21/22] x86, relocs: Ignore L4_PAGE_OFFSET relocations Sami Tolvanen 2020-06-24 20:32 ` [PATCH 22/22] x86, build: allow LTO_CLANG and THINLTO to be selected Sami Tolvanen 2020-06-24 21:15 ` [PATCH 00/22] add support for Clang LTO Peter Zijlstra 2020-06-24 21:30 ` Sami Tolvanen 2020-06-25 8:27 ` Will Deacon 2020-06-24 21:31 ` Nick Desaulniers 2020-06-25 8:03 ` Peter Zijlstra 2020-06-25 8:24 ` Peter Zijlstra 2020-06-25 8:57 ` Peter Zijlstra 2020-06-30 19:19 ` Marco Elver 2020-06-30 20:12 ` Peter Zijlstra 2020-06-30 20:30 ` Paul E. McKenney 2020-07-01 9:10 ` Peter Zijlstra 2020-07-01 14:20 ` David Laight 2020-07-01 16:06 ` Paul E. McKenney 2020-07-02 9:37 ` David Laight 2020-07-02 18:00 ` Paul E. McKenney 2020-07-01 9:41 ` Marco Elver 2020-07-01 10:03 ` Will Deacon 2020-07-01 11:40 ` Peter Zijlstra 2020-07-01 14:06 ` Paul E. McKenney 2020-07-01 15:05 ` Peter Zijlstra 2020-07-01 16:03 ` Paul E. McKenney 2020-07-02 8:20 ` Peter Zijlstra 2020-07-02 17:59 ` Paul E. McKenney 2020-07-03 13:13 ` Peter Zijlstra 2020-07-03 13:25 ` Peter Zijlstra 2020-07-03 14:51 ` Paul E. McKenney 2020-07-03 14:42 ` Paul E. McKenney 2020-07-06 16:26 ` Paul E. McKenney 2020-07-06 18:29 ` Peter Zijlstra 2020-07-06 18:39 ` Paul E. McKenney 2020-07-06 19:40 ` Peter Zijlstra 2020-07-06 23:41 ` Paul E. McKenney 2020-06-28 16:56 ` Masahiro Yamada [this message] 2020-06-29 23:20 ` Sami Tolvanen 2020-07-07 15:51 ` Sami Tolvanen 2020-07-07 16:05 ` Sami Tolvanen 2020-07-07 16:56 ` Jakub Kicinski 2020-07-07 17:17 ` Nick Desaulniers 2020-07-07 17:30 ` Jakub Kicinski 2020-07-11 16:32 ` Paul Menzel 2020-07-12 8:59 ` Sedat Dilek 2020-07-12 18:40 ` Nathan Chancellor 2020-07-14 9:44 ` Sedat Dilek 2020-07-14 17:54 ` Nick Desaulniers 2020-07-12 23:34 ` Sami Tolvanen 2020-07-14 12:16 ` Paul Menzel 2020-07-14 12:35 ` Sedat Dilek 2020-07-14 13:40 ` Paul Menzel 2020-09-03 20:30 ` [PATCH v2 00/28] Add " Sami Tolvanen 2020-09-03 20:30 ` [PATCH v2 01/28] x86/boot/compressed: Disable relocation relaxation Sami Tolvanen 2020-09-03 21:44 ` Kees Cook 2020-09-03 23:42 ` Arvind Sankar 2020-09-04 7:14 ` Nathan Chancellor 2020-09-03 20:30 ` [PATCH v2 02/28] x86/asm: Replace __force_order with memory clobber Sami Tolvanen 2020-09-03 21:45 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 03/28] lib/string.c: implement stpcpy Sami Tolvanen 2020-09-03 21:47 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 04/28] RAS/CEC: Fix cec_init() prototype Sami Tolvanen 2020-09-03 21:50 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 05/28] objtool: Add a pass for generating __mcount_loc Sami Tolvanen 2020-09-03 21:51 ` Kees Cook 2020-09-03 22:03 ` Sami Tolvanen 2020-09-04 9:31 ` peterz 2020-09-10 18:29 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 06/28] objtool: Don't autodetect vmlinux.o Sami Tolvanen 2020-09-03 21:52 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 07/28] kbuild: add support for objtool mcount Sami Tolvanen 2020-09-03 21:56 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 08/28] x86, build: use " Sami Tolvanen 2020-09-03 21:58 ` Kees Cook 2020-09-03 22:11 ` Sami Tolvanen 2020-09-03 20:30 ` [PATCH v2 09/28] kbuild: add support for Clang LTO Sami Tolvanen 2020-09-03 22:08 ` Kees Cook 2020-09-08 17:02 ` Sami Tolvanen 2020-09-05 19:36 ` Masahiro Yamada 2020-09-08 17:10 ` Sami Tolvanen 2020-09-05 20:17 ` Masahiro Yamada 2020-09-08 17:14 ` Sami Tolvanen 2020-09-07 15:30 ` Masahiro Yamada 2020-09-08 17:30 ` Sami Tolvanen 2020-09-03 20:30 ` [PATCH v2 10/28] kbuild: lto: fix module versioning Sami Tolvanen 2020-09-03 22:11 ` Kees Cook 2020-09-08 18:23 ` Sami Tolvanen 2020-09-03 20:30 ` [PATCH v2 11/28] kbuild: lto: postpone objtool Sami Tolvanen 2020-09-03 22:19 ` Kees Cook 2020-09-08 20:56 ` Sami Tolvanen 2020-09-03 20:30 ` [PATCH v2 12/28] kbuild: lto: limit inlining Sami Tolvanen 2020-09-03 22:20 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 13/28] kbuild: lto: merge module sections Sami Tolvanen 2020-09-03 22:23 ` Kees Cook 2020-09-07 15:25 ` Masahiro Yamada 2020-09-08 21:07 ` Sami Tolvanen 2020-09-03 20:30 ` [PATCH v2 14/28] kbuild: lto: remove duplicate dependencies from .mod files Sami Tolvanen 2020-09-03 22:29 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 15/28] init: lto: ensure initcall ordering Sami Tolvanen 2020-09-03 22:40 ` Kees Cook 2020-09-08 21:16 ` Sami Tolvanen 2020-09-10 9:25 ` David Woodhouse 2020-09-10 15:07 ` Sami Tolvanen 2020-09-03 20:30 ` [PATCH v2 16/28] init: lto: fix PREL32 relocations Sami Tolvanen 2020-09-03 22:41 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 17/28] PCI: Fix PREL32 relocations for LTO Sami Tolvanen 2020-09-03 22:42 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 18/28] modpost: lto: strip .lto from module names Sami Tolvanen 2020-09-03 22:42 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 19/28] scripts/mod: disable LTO for empty.c Sami Tolvanen 2020-09-03 22:43 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 20/28] efi/libstub: disable LTO Sami Tolvanen 2020-09-03 22:43 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 21/28] drivers/misc/lkdtm: disable LTO for rodata.o Sami Tolvanen 2020-09-03 20:30 ` [PATCH v2 22/28] arm64: export CC_USING_PATCHABLE_FUNCTION_ENTRY Sami Tolvanen 2020-09-03 22:44 ` Kees Cook 2020-09-08 21:23 ` Sami Tolvanen 2020-09-03 20:30 ` [PATCH v2 23/28] arm64: vdso: disable LTO Sami Tolvanen 2020-09-03 22:45 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 24/28] KVM: arm64: disable LTO for the nVHE directory Sami Tolvanen 2020-09-03 22:45 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 25/28] arm64: allow LTO_CLANG and THINLTO to be selected Sami Tolvanen 2020-09-03 22:45 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 26/28] x86, vdso: disable LTO only for vDSO Sami Tolvanen 2020-09-03 22:46 ` Kees Cook 2020-09-03 20:30 ` [PATCH v2 27/28] x86, relocs: Ignore L4_PAGE_OFFSET relocations Sami Tolvanen 2020-09-03 22:47 ` Kees Cook 2020-09-08 23:28 ` Sami Tolvanen 2020-09-03 20:30 ` [PATCH v2 28/28] x86, build: allow LTO_CLANG and THINLTO to be selected Sami Tolvanen 2020-09-03 22:48 ` Kees Cook 2020-09-03 23:34 ` [PATCH v2 00/28] Add support for Clang LTO Kees Cook 2020-09-04 4:45 ` Nathan Chancellor 2020-09-03 23:38 ` Kees Cook 2020-09-04 7:53 ` Sedat Dilek 2020-09-04 8:55 ` peterz 2020-09-04 9:08 ` Sedat Dilek 2020-09-06 0:24 ` Masahiro Yamada 2020-09-08 23:46 ` Sami Tolvanen 2020-09-10 1:18 ` Masahiro Yamada 2020-09-10 15:17 ` Sami Tolvanen 2020-09-10 18:18 ` Kees Cook
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