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

--- 3.3 Loadable module goals - obj-m

	$(obj-m) specify object files which are built as loadable

	$(obj-m) specifies object files which are built as loadable

	kernel modules.

	A module may be built from one source file or several source

	down in the ext2 directory.

	Kbuild only uses this information to decide that it needs to visit

	the directory, it is the Makefile in the subdirectory that

	specifies what is modules and what is built-in.

	specifies what is modular and what is built-in.

	It is good practice to use a CONFIG_ variable when assigning directory

	names. This allows kbuild to totally skip the directory if the

	echoing information to user in a rule is often a good practice

	but when execution "make -s" one does not expect to see any output

	except for warnings/errors.

	To support this kbuild define $(kecho) which will echo out the

	To support this kbuild defines $(kecho) which will echo out the

	text following $(kecho) to stdout except if "make -s" is used.

	Example:

	The kernel may be built with several different versions of

	$(CC), each supporting a unique set of features and options.

	kbuild provide basic support to check for valid options for $(CC).

	kbuild provides basic support to check for valid options for $(CC).

	$(CC) is usually the gcc compiler, but other alternatives are

	available.

	Note: as-instr-option uses KBUILD_AFLAGS for $(AS) options

    cc-option

	cc-option is used to check if $(CC) supports a given option, and not

	supported to use an optional second option.

	cc-option is used to check if $(CC) supports a given option, and if

	not supported to use an optional second option.

	Example:

		#arch/x86/Makefile

			false ; \

		fi

	In this example for a specific GCC version the build will error out explaining

	to the user why it stops.

	In this example for a specific GCC version the build will error out

	explaining to the user why it stops.

    cc-cross-prefix

	cc-cross-prefix is used to check if there exists a $(CC) in path with

	In the example above the executable is composed of the C++ file

	qconf.cc - identified by $(qconf-cxxobjs).

	If qconf is composed by a mixture of .c and .cc files, then an

	If qconf is composed of a mixture of .c and .cc files, then an

	additional line can be used to identify this.

	Example:

		hostprogs-$(CONFIG_KALLSYMS) += kallsyms

	Kbuild knows about both 'y' for built-in and 'm' for module.

	So if a config symbol evaluate to 'm', kbuild will still build

	So if a config symbol evaluates to 'm', kbuild will still build

	the binary. In other words, Kbuild handles hostprogs-m exactly

	like hostprogs-y. But only hostprogs-y is recommended to be used

	when no CONFIG symbols are involved.

		#drivers/pci/Makefile

		clean-files := devlist.h classlist.h

When executing "make clean", the two files "devlist.h classlist.h" will

be deleted. Kbuild will assume files to be in same relative directory as the

When executing "make clean", the two files "devlist.h classlist.h" will be

deleted. Kbuild will assume files to be in the same relative directory as the

Makefile except if an absolute path is specified (path starting with '/').

To delete a directory hierarchy use:

The above assignment instructs kbuild to descend down in the

directory compressed/ when "make clean" is executed.

To support the clean infrastructure in the Makefiles that builds the

To support the clean infrastructure in the Makefiles that build the

final bootimage there is an optional target named archclean:

	Example:

When kbuild executes, the following steps are followed (roughly):

1) Configuration of the kernel => produce .config

2) Store kernel version in include/linux/version.h

3) Symlink include/asm to include/asm-$(ARCH)

4) Updating all other prerequisites to the target prepare:

3) Updating all other prerequisites to the target prepare:

   - Additional prerequisites are specified in arch/$(ARCH)/Makefile

5) Recursively descend down in all directories listed in

4) Recursively descend down in all directories listed in

   init-* core* drivers-* net-* libs-* and build all targets.

   - The values of the above variables are expanded in arch/$(ARCH)/Makefile.

6) All object files are then linked and the resulting file vmlinux is

5) All object files are then linked and the resulting file vmlinux is

   located at the root of the obj tree.

   The very first objects linked are listed in head-y, assigned by

   arch/$(ARCH)/Makefile.

7) Finally, the architecture-specific part does any required post processing

6) Finally, the architecture-specific part does any required post processing

   and builds the final bootimage.

   - This includes building boot records

   - Preparing initrd images and the like

    KBUILD_AFLAGS_MODULE   Options for $(AS) when building modules

	$(KBUILD_AFLAGS_MODULE) is used to add arch specific options that

	$(KBUILD_AFLAGS_MODULE) is used to add arch-specific options that

	are used for $(AS).

	From commandline AFLAGS_MODULE shall be used (see kbuild.txt).

    KBUILD_CFLAGS_MODULE   Options for $(CC) when building modules

	$(KBUILD_CFLAGS_MODULE) is used to add arch specific options that

	$(KBUILD_CFLAGS_MODULE) is used to add arch-specific options that

	are used for $(CC).

	From commandline CFLAGS_MODULE shall be used (see kbuild.txt).

    KBUILD_LDFLAGS_MODULE   Options for $(LD) when linking modules

	$(KBUILD_LDFLAGS_MODULE) is used to add arch specific options

	$(KBUILD_LDFLAGS_MODULE) is used to add arch-specific options

	used when linking modules. This is often a linker script.

	From commandline LDFLAGS_MODULE shall be used (see kbuild.txt).

    extra-y

	extra-y specify additional targets created in the current

	extra-y specifies additional targets created in the current

	directory, in addition to any targets specified by obj-*.

	Listing all targets in extra-y is required for two purposes:

	Usage:

		target: source(s) FORCE

			$(call if_changed,ld/objcopy/gzip)

			$(call if_changed,ld/objcopy/gzip/...)

	When the rule is evaluated, it is checked to see if any files

	need an update, or the command line has changed since the last

	significant; for instance, the below will fail (note the extra space

	after the comma):

		target: source(s) FORCE

	#WRONG!#	$(call if_changed, ld/objcopy/gzip)

	#WRONG!#	$(call if_changed, ld/objcopy/gzip/...)

    ld

	Link target. Often, LDFLAGS_$@ is used to set specific options to ld.

		2) delete target during make clean

	The ": %: %.o" part of the prerequisite is a shorthand that

	free us from listing the setup.o and bootsect.o files.

	Note: It is a common mistake to forget the "target :=" assignment,

	frees us from listing the setup.o and bootsect.o files.

	Note: It is a common mistake to forget the "targets :=" assignment,

	      resulting in the target file being recompiled for no

	      obvious reason.

		clean-files += *.dtb

		DTC_FLAGS ?= -p 1024

    dtc_cpp

	This is just like dtc as describe above, except that the C pre-

	processor is invoked upon the .dtsp file before compiling the result

	with dtc.

	In order for build dependencies to work, all files compiled using

	dtc_cpp must use the C pre-processor's #include functionality and not

	dtc's /include/ functionality.

	Using the C pre-processor allows use of #define to create named

	constants. In turn, the #defines will typically appear in a header

	file, which may be shared with regular C code. Since the dtc language

	represents a data structure rather than code in C syntax, similar

	restrictions are placed on a header file included by a device tree

	file as for a header file included by an assembly language file.

	In particular, the C pre-processor is passed -x assembler-with-cpp,

	which sets macro __ASSEMBLY__. __DTS__ is also set. These allow header

	files to restrict their content to that compatible with device tree

	source.

	A central rule exists to create $(obj)/%.dtb from $(src)/%.dtsp;

	architecture Makefiles do no need to explicitly write out that rule.

--- 6.8 Custom kbuild commands

	When kbuild is executing with KBUILD_VERBOSE=0, then only a shorthand

	When building the *.lds target, kbuild uses the variables:

	KBUILD_CPPFLAGS	: Set in top-level Makefile

	cppflags-y	: May be set in the kbuild makefile

	CPPFLAGS_$(@F)  : Target specific flags.

	CPPFLAGS_$(@F)  : Target-specific flags.

	                  Note that the full filename is used in this

	                  assignment.

	The kbuild infrastructure for *lds file are used in several

	The kbuild infrastructure for *lds files is used in several

	architecture-specific files.

--- 6.10 Generic header files

=== 7 Kbuild syntax for exported headers

The kernel include a set of headers that is exported to userspace.

The kernel includes a set of headers that is exported to userspace.

Many headers can be exported as-is but other headers require a

minimal pre-processing before they are ready for user-space.

The pre-processing does:

- drop kernel specific annotations

- drop kernel-specific annotations

- drop include of compiler.h

- drop all sections that are kernel internal (guarded by ifdef __KERNEL__)

	--- 7.1 header-y

	header-y specify header files to be exported.

	header-y specifies header files to be exported.

		Example:

			#include/linux/Kbuild

	The convention is to list one file per line and

	preferably in alphabetic order.

	header-y also specify which subdirectories to visit.

	header-y also specifies which subdirectories to visit.

	A subdirectory is identified by a trailing '/' which

	can be seen in the example above for the usb subdirectory.

	--- 7.3 destination-y

	When an architecture have a set of exported headers that needs to be

	When an architecture has a set of exported headers that needs to be

	exported to a different directory destination-y is used.

	destination-y specify the destination directory for all exported

	destination-y specifies the destination directory for all exported

	headers in the file where it is present.

		Example:

    INSTALL_MOD_STRIP

	If this variable is specified, will cause modules to be stripped

	If this variable is specified, it will cause modules to be stripped

	after they are installed.  If INSTALL_MOD_STRIP is '1', then the

	default option --strip-debug will be used.  Otherwise,

	default option --strip-debug will be used.  Otherwise, the

	INSTALL_MOD_STRIP value will be used as the option(s) to the strip

	command.

/// Simplify a trivial if-return sequence.  Possibly combine with a

/// preceding function call.

//

// Confidence: High

// Copyright: (C) 2014 Julia Lawall, INRIA/LIP6.  GPLv2.

// Copyright: (C) 2014 Gilles Muller, INRIA/LiP6.  GPLv2.

// URL: http://coccinelle.lip6.fr/

// Comments:

// Options: --no-includes --include-headers

virtual patch

virtual context

virtual org

virtual report

@r depends on patch@

local idexpression e;

identifier i,f,fn;

@@

fn(...) { <...

- e@i =

+ return

    f(...);

-if (i != 0) return i;

-return 0;

...> }

@depends on patch@

identifier r.i;

type t;

@@

-t i;

 ... when != i

@depends on patch@

expression e;

@@

-if (e != 0)

   return e;

-return 0;

// -----------------------------------------------------------------------

@s1 depends on context || org || report@

local idexpression e;

identifier i,f,fn;

position p,p1,p2;

@@

fn(...) { <...

* e@i@p = f(...);

  if (\(i@p1 != 0\|i@p2 < 0\))

     return i;

  return 0;

...> }

@s2 depends on context || org || report forall@

identifier s1.i;

type t;

position q,s1.p;

expression e,f;

@@

* t i@q;

  ... when != i

  e@p = f(...);

@s3 depends on context || org || report@

expression e;

position p1!=s1.p1;

position p2!=s1.p2;

@@

*if (\(e@p1 != 0\|e@p2 < 0\))

   return e;

 return 0;

// -----------------------------------------------------------------------

@script:python depends on org@

p << s1.p;

p1 << s1.p1;

q << s2.q;

@@

cocci.print_main("decl",q)

cocci.print_secs("use",p)

cocci.include_match(False)

@script:python depends on org@

p << s1.p;

p2 << s1.p2;

q << s2.q;

@@

cocci.print_main("decl",q)

cocci.print_secs("use with questionable test",p)

cocci.include_match(False)

@script:python depends on org@

p << s1.p;

p1 << s1.p1;

@@

cocci.print_main("use",p)

@script:python depends on org@

p << s1.p;

p2 << s1.p2;

@@

cocci.print_main("use with questionable test",p)

@script:python depends on org@

p << s3.p1;

@@

cocci.print_main("test",p)

@script:python depends on org@

p << s3.p2;

@@

cocci.print_main("questionable test",p)

// -----------------------------------------------------------------------

@script:python depends on report@

p << s1.p;

p1 << s1.p1;

q << s2.q;

@@

msg = "WARNING: end returns can be simpified and declaration on line %s can be dropped" % (q[0].line)

coccilib.report.print_report(p[0],msg)

cocci.include_match(False)

@script:python depends on report@

p << s1.p;

p1 << s1.p1;

q << s2.q

;

@@

msg = "WARNING: end returns may be simpified if negative or 0 value and declaration on line %s can be dropped" % (q[0].line)

coccilib.report.print_report(p[0],msg)

cocci.include_match(False)

@script:python depends on report@

p << s1.p;

p1 << s1.p1;

@@

msg = "WARNING: end returns can be simpified"

coccilib.report.print_report(p[0],msg)

@script:python depends on report@

p << s1.p;

p2 << s1.p2;

@@

msg = "WARNING: end returns can be simpified if negative or 0 value"

coccilib.report.print_report(p[0],msg)

@script:python depends on report@

p << s3.p1;

@@

msg = "WARNING: end returns can be simpified"

coccilib.report.print_report(p[0],msg)

@script:python depends on report@

p << s3.p2;

@@

msg = "WARNING: end returns can be simpified if tested value is negative or 0"

coccilib.report.print_report(p[0],msg)

	s390*)

		debarch=s390$(grep -q CONFIG_64BIT=y $KCONFIG_CONFIG && echo x || true) ;;

	ppc*)

		debarch=powerpc ;;

		debarch=$(grep -q CPU_LITTLE_ENDIAN=y $KCONFIG_CONFIG && echo ppc64el || echo powerpc) ;;

	parisc*)

		debarch=hppa ;;

	mips*)

	fi

	# Create the package

	dpkg-gencontrol -isp $forcearch -Vkernel:debarch="${debarch:-$(dpkg --print-architecture)}" -p$pname -P"$pdir"

	dpkg-gencontrol $forcearch -Vkernel:debarch="${debarch:-$(dpkg --print-architecture)}" -p$pname -P"$pdir"

	dpkg --build "$pdir" ..

}

		rmdir "$tmpdir/lib/modules/$version"

	fi

	if [ -n "$BUILD_DEBUG" ] ; then

		(

			cd $tmpdir

			for module in $(find lib/modules/ -name *.ko); do

		for module in $(find $tmpdir/lib/modules/ -name *.ko -printf '%P\n'); do

			module=lib/modules/$module

			mkdir -p $(dirname $dbg_dir/usr/lib/debug/$module)

			# only keep debug symbols in the debug file

				$OBJCOPY --only-keep-debug $module $dbg_dir/usr/lib/debug/$module

			$OBJCOPY --only-keep-debug $tmpdir/$module $dbg_dir/usr/lib/debug/$module

			# strip original module from debug symbols

				$OBJCOPY --strip-debug $module

			$OBJCOPY --strip-debug $tmpdir/$module

			# then add a link to those

				$OBJCOPY --add-gnu-debuglink=$dbg_dir/usr/lib/debug/$module $module

			$OBJCOPY --add-gnu-debuglink=$dbg_dir/usr/lib/debug/$module $tmpdir/$module

		done

		)

	fi

fi

	--regex-c++='/TESTCLEARFLAG_FALSE\(([^,)]*).*/TestClearPage\1/' \

	--regex-c++='/__TESTCLEARFLAG_FALSE\(([^,)]*).*/__TestClearPage\1/' \

	--regex-c++='/_PE\(([^,)]*).*/PEVENT_ERRNO__\1/'		\

	--regex-c++='/TESTPCGFLAG\(([^,)]*).*/PageCgroup\1/'		\

	--regex-c++='/SETPCGFLAG\(([^,)]*).*/SetPageCgroup\1/'		\

	--regex-c++='/CLEARPCGFLAG\(([^,)]*).*/ClearPageCgroup\1/'	\

	--regex-c++='/TESTCLEARPCGFLAG\(([^,)]*).*/TestClearPageCgroup\1/' \

	--regex-c++='/TASK_PFA_TEST\([^,]*,\s*([^)]*)\)/task_\1/'	\

	--regex-c++='/TASK_PFA_SET\([^,]*,\s*([^)]*)\)/task_set_\1/'	\

	--regex-c++='/TASK_PFA_CLEAR\([^,]*,\s*([^)]*)\)/task_clear_\1/'\

	--regex='/__CLEARPAGEFLAG_NOOP(\([^,)]*\).*/__ClearPage\1/' \

	--regex='/TESTCLEARFLAG_FALSE(\([^,)]*\).*/TestClearPage\1/' \

	--regex='/__TESTCLEARFLAG_FALSE(\([^,)]*\).*/__TestClearPage\1/' \

	--regex='/TESTPCGFLAG\(([^,)]*).*/PageCgroup\1/'	\

	--regex='/SETPCGFLAG\(([^,)]*).*/SetPageCgroup\1/'	\

	--regex='/CLEARPCGFLAG\(([^,)]*).*/ClearPageCgroup\1/'	\

	--regex='/TESTCLEARPCGFLAG\(([^,)]*).*/TestClearPageCgroup\1/' \

	--regex='/TASK_PFA_TEST\([^,]*,\s*([^)]*)\)/task_\1/'		\

	--regex='/TASK_PFA_SET\([^,]*,\s*([^)]*)\)/task_set_\1/'	\

	--regex='/TASK_PFA_CLEAR\([^,]*,\s*([^)]*)\)/task_clear_\1/'	\

	--regex='/_PE(\([^,)]*\).*/PEVENT_ERRNO__\1/'		\

	--regex='/PCI_OP_READ(\([a-z]*[a-z]\).*[1-4])/pci_bus_read_config_\1/' \

	--regex='/PCI_OP_WRITE(\([a-z]*[a-z]\).*[1-4])/pci_bus_write_config_\1/'\

	--regex='/DEFINE_HASHTABLE\((\w*)/\1/v/'

	--regex='/[^#]*DEFINE_HASHTABLE(\([^,)]*\)/\1/'

	all_kconfigs | xargs $1 -a                              \

	--regex='/^[ \t]*\(\(menu\)*config\)[ \t]+\([a-zA-Z0-9_]+\)/\3/'