Commit f716a85c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 

Pull kbuild updates from Michal Marek:

 - GCC plugin support by Emese Revfy from grsecurity, with a fixup from
   Kees Cook.  The plugins are meant to be used for static analysis of
   the kernel code.  Two plugins are provided already.

 - reduction of the gcc commandline by Arnd Bergmann.

 - IS_ENABLED / IS_REACHABLE macro enhancements by Masahiro Yamada

 - bin2c fix by Michael Tautschnig

 - setlocalversion fix by Wolfram Sang

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  gcc-plugins: disable under COMPILE_TEST
  kbuild: Abort build on bad stack protector flag
  scripts: Fix size mismatch of kexec_purgatory_size
  kbuild: make samples depend on headers_install
  Kbuild: don't add obj tree in additional includes
  Kbuild: arch: look for generated headers in obtree
  Kbuild: always prefix objtree in LINUXINCLUDE
  Kbuild: avoid duplicate include path
  Kbuild: don't add ../../ to include path
  vmlinux.lds.h: replace config_enabled() with IS_ENABLED()
  kconfig.h: allow to use IS_{ENABLE,REACHABLE} in macro expansion
  kconfig.h: use already defined macros for IS_REACHABLE() define
  export.h: use __is_defined() to check if __KSYM_* is defined
  kconfig.h: use __is_defined() to check if MODULE is defined
  kbuild: setlocalversion: print error to STDERR
  Add sancov plugin
  Add Cyclomatic complexity GCC plugin
  GCC plugin infrastructure
  Shared library support
parents 221bb8a4 a519167e

.gitignore

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ modules.builtin 
Module.symvers

*.dwo

*.su

*.c.[012]*.*



#

# Top-level generic files

Documentation/dontdiff

+1 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
*.bc

*.bin

*.bz2

*.c.[012]*.*

*.cis

*.cpio

*.csp

Documentation/gcc-plugins.txt

0 → 100644
+87 −0
Original line number Diff line number Diff line 
GCC plugin infrastructure

=========================





1. Introduction

===============



GCC plugins are loadable modules that provide extra features to the

compiler [1]. They are useful for runtime instrumentation and static analysis.

We can analyse, change and add further code during compilation via

callbacks [2], GIMPLE [3], IPA [4] and RTL passes [5].



The GCC plugin infrastructure of the kernel supports all gcc versions from

4.5 to 6.0, building out-of-tree modules, cross-compilation and building in a

separate directory.

Plugin source files have to be compilable by both a C and a C++ compiler as well

because gcc versions 4.5 and 4.6 are compiled by a C compiler,

gcc-4.7 can be compiled by a C or a C++ compiler,

and versions 4.8+ can only be compiled by a C++ compiler.



Currently the GCC plugin infrastructure supports only the x86, arm and arm64

architectures.



This infrastructure was ported from grsecurity [6] and PaX [7].



--

[1] https://gcc.gnu.org/onlinedocs/gccint/Plugins.html

[2] https://gcc.gnu.org/onlinedocs/gccint/Plugin-API.html#Plugin-API

[3] https://gcc.gnu.org/onlinedocs/gccint/GIMPLE.html

[4] https://gcc.gnu.org/onlinedocs/gccint/IPA.html

[5] https://gcc.gnu.org/onlinedocs/gccint/RTL.html

[6] https://grsecurity.net/

[7] https://pax.grsecurity.net/





2. Files

========



$(src)/scripts/gcc-plugins

	This is the directory of the GCC plugins.



$(src)/scripts/gcc-plugins/gcc-common.h

	This is a compatibility header for GCC plugins.

	It should be always included instead of individual gcc headers.



$(src)/scripts/gcc-plugin.sh

	This script checks the availability of the included headers in

	gcc-common.h and chooses the proper host compiler to build the plugins

	(gcc-4.7 can be built by either gcc or g++).



$(src)/scripts/gcc-plugins/gcc-generate-gimple-pass.h

$(src)/scripts/gcc-plugins/gcc-generate-ipa-pass.h

$(src)/scripts/gcc-plugins/gcc-generate-simple_ipa-pass.h

$(src)/scripts/gcc-plugins/gcc-generate-rtl-pass.h

	These headers automatically generate the registration structures for

	GIMPLE, SIMPLE_IPA, IPA and RTL passes. They support all gcc versions

	from 4.5 to 6.0.

	They should be preferred to creating the structures by hand.





3. Usage

========



You must install the gcc plugin headers for your gcc version,

e.g., on Ubuntu for gcc-4.9:



	apt-get install gcc-4.9-plugin-dev



Enable a GCC plugin based feature in the kernel config:



	CONFIG_GCC_PLUGIN_CYC_COMPLEXITY = y



To compile only the plugin(s):



	make gcc-plugins



or just run the kernel make and compile the whole kernel with

the cyclomatic complexity GCC plugin.





4. How to add a new GCC plugin

==============================



The GCC plugins are in $(src)/scripts/gcc-plugins/. You can use a file or a directory

here. It must be added to $(src)/scripts/gcc-plugins/Makefile,

$(src)/scripts/Makefile.gcc-plugins and $(src)/arch/Kconfig.

See the cyc_complexity_plugin.c (CONFIG_GCC_PLUGIN_CYC_COMPLEXITY) GCC plugin.

MAINTAINERS

+9 −0
Original line number Diff line number Diff line
@@ -5094,6 +5094,15 @@ L: linux-scsi@vger.kernel.org 
S:	Odd Fixes (e.g., new signatures)

F:	drivers/scsi/fdomain.*



GCC PLUGINS

M:	Kees Cook <keescook@chromium.org>

R:	Emese Revfy <re.emese@gmail.com>

L:	kernel-hardening@lists.openwall.com

S:	Maintained

F:	scripts/gcc-plugins/

F:	scripts/gcc-plugin.sh

F:	Documentation/gcc-plugins.txt



GCOV BASED KERNEL PROFILING

M:	Peter Oberparleiter <oberpar@linux.vnet.ibm.com>

S:	Maintained

Makefile

+23 −22
Original line number Diff line number Diff line
@@ -371,26 +371,27 @@ CFLAGS_KERNEL = 
AFLAGS_KERNEL	=

LDFLAGS_vmlinux =

CFLAGS_GCOV	= -fprofile-arcs -ftest-coverage -fno-tree-loop-im

CFLAGS_KCOV	= -fsanitize-coverage=trace-pc

CFLAGS_KCOV	:= $(call cc-option,-fsanitize-coverage=trace-pc,)





# Use USERINCLUDE when you must reference the UAPI directories only.

USERINCLUDE    := \

		-I$(srctree)/arch/$(hdr-arch)/include/uapi \

		-Iarch/$(hdr-arch)/include/generated/uapi \

		-I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \

		-I$(srctree)/include/uapi \

		-Iinclude/generated/uapi \

		-I$(objtree)/include/generated/uapi \

                -include $(srctree)/include/linux/kconfig.h



# Use LINUXINCLUDE when you must reference the include/ directory.

# Needed to be compatible with the O= option

LINUXINCLUDE    := \

		-I$(srctree)/arch/$(hdr-arch)/include \

		-Iarch/$(hdr-arch)/include/generated/uapi \

		-Iarch/$(hdr-arch)/include/generated \

		-I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \

		-I$(objtree)/arch/$(hdr-arch)/include/generated \

		$(if $(KBUILD_SRC), -I$(srctree)/include) \

		-Iinclude \

		$(USERINCLUDE)

		-I$(objtree)/include



LINUXINCLUDE	+= $(filter-out $(LINUXINCLUDE),$(USERINCLUDE))



KBUILD_CPPFLAGS := -D__KERNEL__
@@ -554,7 +555,7 @@ ifeq ($(KBUILD_EXTMOD),) 
# in parallel

PHONY += scripts

scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \

	 asm-generic

	 asm-generic gcc-plugins

	$(Q)$(MAKE) $(build)=$(@)



# Objects we will link into vmlinux / subdirs we need to visit
@@ -635,6 +636,15 @@ endif 
# Tell gcc to never replace conditional load with a non-conditional one

KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)



PHONY += gcc-plugins

gcc-plugins: scripts_basic

ifdef CONFIG_GCC_PLUGINS

	$(Q)$(MAKE) $(build)=scripts/gcc-plugins

endif

	@:



include scripts/Makefile.gcc-plugins



ifdef CONFIG_READABLE_ASM

# Disable optimizations that make assembler listings hard to read.

# reorder blocks reorders the control in the function
@@ -666,21 +676,11 @@ endif 
endif

# Find arch-specific stack protector compiler sanity-checking script.

ifdef CONFIG_CC_STACKPROTECTOR

  stackp-path := $(srctree)/scripts/gcc-$(ARCH)_$(BITS)-has-stack-protector.sh

  ifneq ($(wildcard $(stackp-path)),)

    stackp-check := $(stackp-path)

  endif

  stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh

  stackp-check := $(wildcard $(stackp-path))

endif

KBUILD_CFLAGS += $(stackp-flag)



ifdef CONFIG_KCOV

  ifeq ($(call cc-option, $(CFLAGS_KCOV)),)

    $(warning Cannot use CONFIG_KCOV: \

             -fsanitize-coverage=trace-pc is not supported by compiler)

    CFLAGS_KCOV =

  endif

endif



ifeq ($(cc-name),clang)

KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)

KBUILD_CPPFLAGS += $(call cc-option,-Wno-unknown-warning-option,)
@@ -1019,7 +1019,7 @@ prepare1: prepare2 $(version_h) include/generated/utsrelease.h \ 


archprepare: archheaders archscripts prepare1 scripts_basic



prepare0: archprepare

prepare0: archprepare gcc-plugins

	$(Q)$(MAKE) $(build)=.



# All the preparing..
@@ -1531,6 +1531,7 @@ clean: $(clean-dirs) 
		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \

		-o -name '*.symtypes' -o -name 'modules.order' \

		-o -name modules.builtin -o -name '.tmp_*.o.*' \

		-o -name '*.c.[012]*.*' \

		-o -name '*.gcno' \) -type f -print | xargs rm -f



# Generate tags for editors
@@ -1641,7 +1642,7 @@ endif 
	$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \

	$(build)=$(build-dir)

# Make sure the latest headers are built for Documentation

Documentation/: headers_install

Documentation/ samples/: headers_install

%/: prepare scripts FORCE

	$(cmd_crmodverdir)

	$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \

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