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
2026-05-01 15:00:59 -07:00 · 2016-08-02 16:37:12 -04:00
parent 221bb8a46e a519167e75
commit f716a85cd6
43 changed files with 2252 additions and 54 deletions
@@ -37,6 +37,7 @@ modules.builtin
 Module.symvers
 *.dwo
 *.su
+*.c.[012]*.*

 #
 # Top-level generic files
@@ -3,6 +3,7 @@
 *.bc
 *.bin
 *.bz2
+*.c.[012]*.*
 *.cis
 *.cpio
 *.csp
@@ -0,0 +1,87 @@
+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.
@@ -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
@@ -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) \
@@ -357,6 +357,43 @@ config SECCOMP_FILTER

 	  See Documentation/prctl/seccomp_filter.txt for details.

+config HAVE_GCC_PLUGINS
+	bool
+	help
+	  An arch should select this symbol if it supports building with
+	  GCC plugins.
+
+menuconfig GCC_PLUGINS
+	bool "GCC plugins"
+	depends on HAVE_GCC_PLUGINS
+	depends on !COMPILE_TEST
+	help
+	  GCC plugins are loadable modules that provide extra features to the
+	  compiler. They are useful for runtime instrumentation and static analysis.
+
+	  See Documentation/gcc-plugins.txt for details.
+
+config GCC_PLUGIN_CYC_COMPLEXITY
+	bool "Compute the cyclomatic complexity of a function"
+	depends on GCC_PLUGINS
+	help
+	  The complexity M of a function's control flow graph is defined as:
+	   M = E - N + 2P
+	  where
+
+	  E = the number of edges
+	  N = the number of nodes
+	  P = the number of connected components (exit nodes).
+
+config GCC_PLUGIN_SANCOV
+	bool
+	depends on GCC_PLUGINS
+	help
+	  This plugin inserts a __sanitizer_cov_trace_pc() call at the start of
+	  basic blocks. It supports all gcc versions with plugin support (from
+	  gcc-4.5 on). It is based on the commit "Add fuzzing coverage support"
+	  by Dmitry Vyukov <dvyukov@google.com>.
+
 config HAVE_CC_STACKPROTECTOR
 	bool
 	help
@@ -15,7 +15,7 @@ targets		:= vmlinux.gz vmlinux \
 OBJSTRIP	:= $(obj)/tools/objstrip

 HOSTCFLAGS	:= -Wall -I$(objtree)/usr/include
-BOOTCFLAGS	+= -I$(obj) -I$(srctree)/$(obj)
+BOOTCFLAGS	+= -I$(objtree)/$(obj) -I$(srctree)/$(obj)

 # SRM bootable image.  Copy to offset 512 of a partition.
 $(obj)/bootimage: $(addprefix $(obj)/tools/,mkbb lxboot bootlx) $(obj)/vmlinux.nh
@@ -54,6 +54,7 @@ config ARM
 	select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL)
 	select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL)
 	select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
+	select HAVE_GCC_PLUGINS
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_HW_BREAKPOINT if (PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7))
 	select HAVE_IDE if PCI || ISA || PCMCIA
@@ -78,6 +78,7 @@ config ARM64
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
+	select HAVE_GCC_PLUGINS
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_HW_BREAKPOINT if PERF_EVENTS
 	select HAVE_IRQ_TIME_ACCOUNTING
@@ -43,7 +43,7 @@ ifeq ($(call cc-option-yn, -fstack-protector),y)
 BOOTCFLAGS	+= -fno-stack-protector
 endif

-BOOTCFLAGS	+= -I$(obj) -I$(srctree)/$(obj)
+BOOTCFLAGS	+= -I$(objtree)/$(obj) -I$(srctree)/$(obj)

 DTC_FLAGS	?= -p 1024

@@ -20,7 +20,7 @@ common-objs-y += powerpc.o emulate.o emulate_loadstore.o
 obj-$(CONFIG_KVM_EXIT_TIMING) += timing.o
 obj-$(CONFIG_KVM_BOOK3S_HANDLER) += book3s_exports.o

-AFLAGS_booke_interrupts.o := -I$(obj)
+AFLAGS_booke_interrupts.o := -I$(objtree)/$(obj)

 kvm-e500-objs := \
 	$(common-objs-y) \
@@ -33,10 +33,10 @@ quiet_cmd_sizes = GEN $@
 $(obj)/sizes.h: vmlinux
 	$(call if_changed,sizes)

-AFLAGS_head.o += -I$(obj)
+AFLAGS_head.o += -I$(objtree)/$(obj)
 $(obj)/head.o: $(obj)/sizes.h

-CFLAGS_misc.o += -I$(obj)
+CFLAGS_misc.o += -I$(objtree)/$(obj)
 $(obj)/misc.o: $(obj)/sizes.h

 OBJCOPYFLAGS_vmlinux.bin :=  -R .comment -S
@@ -9,6 +9,7 @@ config UML
 	select GENERIC_CPU_DEVICES
 	select GENERIC_IO
 	select GENERIC_CLOCKEVENTS
+	select HAVE_GCC_PLUGINS
 	select TTY # Needed for line.c

 config MMU
@@ -78,8 +78,8 @@ include $(ARCH_DIR)/Makefile-os-$(OS)

 KBUILD_CPPFLAGS += -I$(srctree)/$(HOST_DIR)/include \
 		   -I$(srctree)/$(HOST_DIR)/include/uapi \
-		   -I$(HOST_DIR)/include/generated \
-		   -I$(HOST_DIR)/include/generated/uapi
+		   -I$(objtree)/$(HOST_DIR)/include/generated \
+		   -I$(objtree)/$(HOST_DIR)/include/generated/uapi

 # -Derrno=kernel_errno - This turns all kernel references to errno into
 # kernel_errno to separate them from the libc errno.  This allows -fno-common
@@ -111,6 +111,7 @@ config X86
 	select HAVE_FUNCTION_GRAPH_FP_TEST
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_TRACER
+	select HAVE_GCC_PLUGINS
 	select HAVE_GENERIC_DMA_COHERENT	if X86_32
 	select HAVE_HW_BREAKPOINT
 	select HAVE_IDE
@@ -96,7 +96,7 @@ $(obj)/zoffset.h: $(obj)/compressed/vmlinux FORCE
 	$(call if_changed,zoffset)


-AFLAGS_header.o += -I$(obj)
+AFLAGS_header.o += -I$(objtree)/$(obj)
 $(obj)/header.o: $(obj)/zoffset.h

 LDFLAGS_setup.elf	:= -T
@@ -75,7 +75,7 @@ CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
       -fno-omit-frame-pointer -foptimize-sibling-calls \
       -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO

-$(vobjs): KBUILD_CFLAGS += $(CFL)
+$(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)

 #
 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
@@ -145,6 +145,7 @@ KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
+KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
 KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
@@ -8,6 +8,8 @@ PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))
 LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefaultlib
 targets += purgatory.ro

+KCOV_INSTRUMENT := n
+
 # Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That
 # in turn leaves some undefined symbols like __fentry__ in purgatory and not
 # sure how to relocate those. Like kexec-tools, use custom flags.
@@ -48,7 +48,7 @@ targets += realmode.lds
 $(obj)/realmode.lds: $(obj)/pasyms.h

 LDFLAGS_realmode.elf := --emit-relocs -T
-CPPFLAGS_realmode.lds += -P -C -I$(obj)
+CPPFLAGS_realmode.lds += -P -C -I$(objtree)/$(obj)

 targets += realmode.elf
 $(obj)/realmode.elf: $(obj)/realmode.lds $(REALMODE_OBJS) FORCE
@@ -164,7 +164,7 @@

 #define ___OF_TABLE(cfg, name)	_OF_TABLE_##cfg(name)
 #define __OF_TABLE(cfg, name)	___OF_TABLE(cfg, name)
-#define OF_TABLE(cfg, name)	__OF_TABLE(config_enabled(cfg), name)
+#define OF_TABLE(cfg, name)	__OF_TABLE(IS_ENABLED(cfg), name)
 #define _OF_TABLE_0(name)
 #define _OF_TABLE_1(name)						\
 	. = ALIGN(8);							\
--- a/Show More
+++ b/Show More