From 20bf2b378729c4a0366a53e2018a0b70ace94bcd Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Thu, 28 Jan 2021 15:52:19 -0600 Subject: x86/build: Disable CET instrumentation in the kernel With retpolines disabled, some configurations of GCC, and specifically the GCC versions 9 and 10 in Ubuntu will add Intel CET instrumentation to the kernel by default. That breaks certain tracing scenarios by adding a superfluous ENDBR64 instruction before the fentry call, for functions which can be called indirectly. CET instrumentation isn't currently necessary in the kernel, as CET is only supported in user space. Disable it unconditionally and move it into the x86's Makefile as CET/CFI... enablement should be a per-arch decision anyway. [ bp: Massage and extend commit message. ] Fixes: 29be86d7f9cb ("kbuild: add -fcf-protection=none when using retpoline flags") Reported-by: Nikolay Borisov Signed-off-by: Josh Poimboeuf Signed-off-by: Borislav Petkov Reviewed-by: Nikolay Borisov Tested-by: Nikolay Borisov Cc: Cc: Seth Forshee Cc: Masahiro Yamada Link: https://lkml.kernel.org/r/20210128215219.6kct3h2eiustncws@treble --- Makefile | 6 ------ 1 file changed, 6 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index e0af7a4a5598..51c2bf34142d 100644 --- a/Makefile +++ b/Makefile @@ -948,12 +948,6 @@ KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init) # change __FILE__ to the relative path from the srctree KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) -# ensure -fcf-protection is disabled when using retpoline as it is -# incompatible with -mindirect-branch=thunk-extern -ifdef CONFIG_RETPOLINE -KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none) -endif - # include additional Makefiles when needed include-y := scripts/Makefile.extrawarn include-$(CONFIG_KASAN) += scripts/Makefile.kasan -- cgit v1.2.3 From d8d2d38275c1b2d3936c0d809e0559e88912fbb5 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 1 Feb 2021 10:00:24 +0900 Subject: kbuild: remove PYTHON variable Python retired in 2020, and some distributions do not provide the 'python' command any more. As in commit 51839e29cb59 ("scripts: switch explicitly to Python 3"), we need to use more specific 'python3' to invoke scripts even if they are written in a way compatible with both Python 2 and 3. This commit removes the variable 'PYTHON', and switches the existing users to 'PYTHON3'. BTW, PEP 394 (https://www.python.org/dev/peps/pep-0394/) is a helpful material. Signed-off-by: Masahiro Yamada --- Documentation/Makefile | 2 +- Documentation/kbuild/makefiles.rst | 2 +- Makefile | 3 +-- arch/ia64/Makefile | 2 +- arch/ia64/scripts/unwcheck.py | 2 +- scripts/jobserver-exec | 2 +- 6 files changed, 6 insertions(+), 7 deletions(-) (limited to 'Makefile') diff --git a/Documentation/Makefile b/Documentation/Makefile index 61a7310b49e0..9c42dde97671 100644 --- a/Documentation/Makefile +++ b/Documentation/Makefile @@ -75,7 +75,7 @@ quiet_cmd_sphinx = SPHINX $@ --> file://$(abspath $(BUILDDIR)/$3/$4) cmd_sphinx = $(MAKE) BUILDDIR=$(abspath $(BUILDDIR)) $(build)=Documentation/userspace-api/media $2 && \ PYTHONDONTWRITEBYTECODE=1 \ BUILDDIR=$(abspath $(BUILDDIR)) SPHINX_CONF=$(abspath $(srctree)/$(src)/$5/$(SPHINX_CONF)) \ - $(PYTHON) $(srctree)/scripts/jobserver-exec \ + $(PYTHON3) $(srctree)/scripts/jobserver-exec \ $(SHELL) $(srctree)/Documentation/sphinx/parallel-wrapper.sh \ $(SPHINXBUILD) \ -b $2 \ diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst index 9f6a11881951..300d8edcb994 100644 --- a/Documentation/kbuild/makefiles.rst +++ b/Documentation/kbuild/makefiles.rst @@ -755,7 +755,7 @@ more details, with real examples. bits on the scripts nonetheless. Kbuild provides variables $(CONFIG_SHELL), $(AWK), $(PERL), - $(PYTHON) and $(PYTHON3) to refer to interpreters for the respective + and $(PYTHON3) to refer to interpreters for the respective scripts. Example:: diff --git a/Makefile b/Makefile index b0e4767735dc..89217e4e68c6 100644 --- a/Makefile +++ b/Makefile @@ -452,7 +452,6 @@ AWK = awk INSTALLKERNEL := installkernel DEPMOD = depmod PERL = perl -PYTHON = python PYTHON3 = python3 CHECK = sparse BASH = bash @@ -508,7 +507,7 @@ CLANG_FLAGS := export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL -export PERL PYTHON PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX +export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE diff --git a/arch/ia64/Makefile b/arch/ia64/Makefile index 703b1c4f6d12..45d5368d6a99 100644 --- a/arch/ia64/Makefile +++ b/arch/ia64/Makefile @@ -69,7 +69,7 @@ vmlinux.bin: vmlinux FORCE $(call if_changed,objcopy) unwcheck: vmlinux - -$(Q)READELF=$(READELF) $(PYTHON) $(srctree)/arch/ia64/scripts/unwcheck.py $< + -$(Q)READELF=$(READELF) $(PYTHON3) $(srctree)/arch/ia64/scripts/unwcheck.py $< archclean: diff --git a/arch/ia64/scripts/unwcheck.py b/arch/ia64/scripts/unwcheck.py index bfd1b671e35f..9581742f0db2 100644 --- a/arch/ia64/scripts/unwcheck.py +++ b/arch/ia64/scripts/unwcheck.py @@ -1,4 +1,4 @@ -#!/usr/bin/env python +#!/usr/bin/env python3 # SPDX-License-Identifier: GPL-2.0 # # Usage: unwcheck.py FILE diff --git a/scripts/jobserver-exec b/scripts/jobserver-exec index 0fdb31a790a8..48d141e3ec56 100755 --- a/scripts/jobserver-exec +++ b/scripts/jobserver-exec @@ -1,4 +1,4 @@ -#!/usr/bin/env python +#!/usr/bin/env python3 # SPDX-License-Identifier: GPL-2.0+ # # This determines how many parallel tasks "make" is expecting, as it is -- cgit v1.2.3 From 315da87c0f99a4741a639782d59dae44878199f5 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 3 Feb 2021 16:52:39 +0900 Subject: kbuild: fix duplicated flags in DEBUG_CFLAGS Sedat Dilek noticed duplicated flags in DEBUG_CFLAGS when building deb-pkg with CONFIG_DEBUG_INFO. For example, 'make CC=clang bindeb-pkg' reproduces the issue. Kbuild recurses to the top Makefile for some targets such as package builds. With commit 121c5d08d53c ("kbuild: Only add -fno-var-tracking-assignments for old GCC versions") applied, DEBUG_CFLAGS is now reset only when CONFIG_CC_IS_GCC=y. Fix it to reset DEBUG_CFLAGS all the time. Fixes: 121c5d08d53c ("kbuild: Only add -fno-var-tracking-assignments for old GCC versions") Reported-by: Sedat Dilek Signed-off-by: Masahiro Yamada Tested-by: Sedat Dilek Reviewed-by: Mark Wielaard Reviewed-by: Nathan Chancellor --- Makefile | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 89217e4e68c6..97c781cf042b 100644 --- a/Makefile +++ b/Makefile @@ -811,10 +811,12 @@ KBUILD_CFLAGS += -ftrivial-auto-var-init=zero KBUILD_CFLAGS += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang endif +DEBUG_CFLAGS := + # Workaround for GCC versions < 5.0 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801 ifdef CONFIG_CC_IS_GCC -DEBUG_CFLAGS := $(call cc-ifversion, -lt, 0500, $(call cc-option, -fno-var-tracking-assignments)) +DEBUG_CFLAGS += $(call cc-ifversion, -lt, 0500, $(call cc-option, -fno-var-tracking-assignments)) endif ifdef CONFIG_DEBUG_INFO -- cgit v1.2.3 From 92bf22614b21a2706f4993b278017e437f7785b3 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 7 Feb 2021 13:57:38 -0800 Subject: Linux 5.11-rc7 --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 70035c522bd3..ade44ac4cc2f 100644 --- a/Makefile +++ b/Makefile @@ -2,7 +2,7 @@ VERSION = 5 PATCHLEVEL = 11 SUBLEVEL = 0 -EXTRAVERSION = -rc6 +EXTRAVERSION = -rc7 NAME = Kleptomaniac Octopus # *DOCUMENTATION* -- cgit v1.2.3