From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: [PATCH v4 06/17] efi/libstub: Disable -mbranch-protection Date: Sun, 28 Jun 2020 23:18:29 -0700 Message-ID: <20200629061840.4065483-7-keescook@chromium.org> References: <20200629061840.4065483-1-keescook@chromium.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200629061840.4065483-1-keescook@chromium.org> Sender: linux-kernel-owner@vger.kernel.org To: Will Deacon Cc: Kees Cook , Ard Biesheuvel , Arvind Sankar , Atish Patra , linux-efi@vger.kernel.org, Catalin Marinas , Mark Rutland , Peter Collingbourne , James Morse , Borislav Petkov , Thomas Gleixner , Ingo Molnar , Russell King , Masahiro Yamada , Nick Desaulniers , Nathan Chancellor , Arnd Bergmann , x86@kernel.org, clang-built-linux@googlegroups.com, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.ke List-Id: linux-arch.vger.kernel.org In preparation for adding --orphan-handling=warn to more architectures, this disables -mbranch-protection, as EFI does not yet support it[1]. This was noticed due to it producing unwanted .note.gnu.property sections (prefixed with .init due to the objcopy build step). [1] https://lore.kernel.org/lkml/CAMj1kXHck12juGi=E=P4hWP_8vQhQ+-x3vBMc3TGeRWdQ-XkxQ@mail.gmail.com Cc: Ard Biesheuvel Cc: Arvind Sankar Cc: Atish Patra Cc: linux-efi@vger.kernel.org Signed-off-by: Kees Cook --- drivers/firmware/efi/libstub/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 75daaf20374e..10fa342ef40c 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -18,7 +18,8 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ \ # arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly # disable the stackleak plugin cflags-$(CONFIG_ARM64) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ - -fpie $(DISABLE_STACKLEAK_PLUGIN) + -fpie $(DISABLE_STACKLEAK_PLUGIN) \ + $(call cc-option,-mbranch-protection=none) cflags-$(CONFIG_ARM) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ -fno-builtin -fpic \ $(call cc-option,-mno-single-pic-base) -- 2.25.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730997AbgF2TMm (ORCPT ); Mon, 29 Jun 2020 15:12:42 -0400 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED5A5C08EAFC for ; Sun, 28 Jun 2020 23:18:49 -0700 (PDT) Received: by mail-pj1-x1044.google.com with SMTP id u8so7309821pje.4 for ; Sun, 28 Jun 2020 23:18:49 -0700 (PDT) From: Kees Cook Subject: [PATCH v4 06/17] efi/libstub: Disable -mbranch-protection Date: Sun, 28 Jun 2020 23:18:29 -0700 Message-ID: <20200629061840.4065483-7-keescook@chromium.org> In-Reply-To: <20200629061840.4065483-1-keescook@chromium.org> References: <20200629061840.4065483-1-keescook@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Will Deacon Cc: Kees Cook , Ard Biesheuvel , Arvind Sankar , Atish Patra , linux-efi@vger.kernel.org, Catalin Marinas , Mark Rutland , Peter Collingbourne , James Morse , Borislav Petkov , Thomas Gleixner , Ingo Molnar , Russell King , Masahiro Yamada , Nick Desaulniers , Nathan Chancellor , Arnd Bergmann , x86@kernel.org, clang-built-linux@googlegroups.com, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Message-ID: <20200629061829.Q0aVIZqNjbsM3KslcUyQYKCWryiwqU2iVjaW-esglqw@z> In preparation for adding --orphan-handling=warn to more architectures, this disables -mbranch-protection, as EFI does not yet support it[1]. This was noticed due to it producing unwanted .note.gnu.property sections (prefixed with .init due to the objcopy build step). [1] https://lore.kernel.org/lkml/CAMj1kXHck12juGi=E=P4hWP_8vQhQ+-x3vBMc3TGeRWdQ-XkxQ@mail.gmail.com Cc: Ard Biesheuvel Cc: Arvind Sankar Cc: Atish Patra Cc: linux-efi@vger.kernel.org Signed-off-by: Kees Cook --- drivers/firmware/efi/libstub/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 75daaf20374e..10fa342ef40c 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -18,7 +18,8 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ \ # arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly # disable the stackleak plugin cflags-$(CONFIG_ARM64) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ - -fpie $(DISABLE_STACKLEAK_PLUGIN) + -fpie $(DISABLE_STACKLEAK_PLUGIN) \ + $(call cc-option,-mbranch-protection=none) cflags-$(CONFIG_ARM) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ -fno-builtin -fpic \ $(call cc-option,-mno-single-pic-base) -- 2.25.1