diff options
60 files changed, 883 insertions, 757 deletions
diff --git a/.gitignore b/.gitignore index 2258e906f01c..87b9dd8a163b 100644 --- a/.gitignore +++ b/.gitignore @@ -56,6 +56,7 @@ modules.order /linux /vmlinux /vmlinux.32 +/vmlinux.symvers /vmlinux-gdb.py /vmlinuz /System.map diff --git a/Documentation/dontdiff b/Documentation/dontdiff index 72fc2e9e2b63..ef9519c32c55 100644 --- a/Documentation/dontdiff +++ b/Documentation/dontdiff @@ -251,6 +251,7 @@ vmlinux-* vmlinux.aout vmlinux.bin.all vmlinux.lds +vmlinux.symvers vmlinuz voffset.h vsyscall.lds diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst index b80257a03830..6515ebc12b6f 100644 --- a/Documentation/kbuild/makefiles.rst +++ b/Documentation/kbuild/makefiles.rst @@ -29,31 +29,37 @@ This document describes the Linux kernel Makefiles. --- 4.4 Controlling compiler options for host programs --- 4.5 When host programs are actually built - === 5 Kbuild clean infrastructure - - === 6 Architecture Makefiles - --- 6.1 Set variables to tweak the build to the architecture - --- 6.2 Add prerequisites to archheaders: - --- 6.3 Add prerequisites to archprepare: - --- 6.4 List directories to visit when descending - --- 6.5 Architecture-specific boot images - --- 6.6 Building non-kbuild targets - --- 6.7 Commands useful for building a boot image - --- 6.8 Custom kbuild commands - --- 6.9 Preprocessing linker scripts - --- 6.10 Generic header files - --- 6.11 Post-link pass - - === 7 Kbuild syntax for exported headers - --- 7.1 no-export-headers - --- 7.2 generic-y - --- 7.3 generated-y - --- 7.4 mandatory-y - - === 8 Kbuild Variables - === 9 Makefile language - === 10 Credits - === 11 TODO + === 5 Userspace Program support + --- 5.1 Simple Userspace Program + --- 5.2 Composite Userspace Programs + --- 5.3 Controlling compiler options for userspace programs + --- 5.4 When userspace programs are actually built + + === 6 Kbuild clean infrastructure + + === 7 Architecture Makefiles + --- 7.1 Set variables to tweak the build to the architecture + --- 7.2 Add prerequisites to archheaders: + --- 7.3 Add prerequisites to archprepare: + --- 7.4 List directories to visit when descending + --- 7.5 Architecture-specific boot images + --- 7.6 Building non-kbuild targets + --- 7.7 Commands useful for building a boot image + --- 7.8 Custom kbuild commands + --- 7.9 Preprocessing linker scripts + --- 7.10 Generic header files + --- 7.11 Post-link pass + + === 8 Kbuild syntax for exported headers + --- 8.1 no-export-headers + --- 8.2 generic-y + --- 8.3 generated-y + --- 8.4 mandatory-y + + === 9 Kbuild Variables + === 10 Makefile language + === 11 Credits + === 12 TODO 1 Overview ========== @@ -732,7 +738,88 @@ Both possibilities are described in the following. This will tell kbuild to build lxdialog even if not referenced in any rule. -5 Kbuild clean infrastructure +5 Userspace Program support +=========================== + +Just like host programs, Kbuild also supports building userspace executables +for the target architecture (i.e. the same architecture as you are building +the kernel for). + +The syntax is quite similar. The difference is to use "userprogs" instead of +"hostprogs". + +5.1 Simple Userspace Program +---------------------------- + + The following line tells kbuild that the program bpf-direct shall be + built for the target architecture. + + Example:: + + userprogs := bpf-direct + + Kbuild assumes in the above example that bpf-direct is made from a + single C source file named bpf-direct.c located in the same directory + as the Makefile. + +5.2 Composite Userspace Programs +-------------------------------- + + Userspace programs can be made up based on composite objects. + The syntax used to define composite objects for userspace programs is + similar to the syntax used for kernel objects. + $(<executable>-objs) lists all objects used to link the final + executable. + + Example:: + + #samples/seccomp/Makefile + userprogs := bpf-fancy + bpf-fancy-objs := bpf-fancy.o bpf-helper.o + + Objects with extension .o are compiled from the corresponding .c + files. In the above example, bpf-fancy.c is compiled to bpf-fancy.o + and bpf-helper.c is compiled to bpf-helper.o. + + Finally, the two .o files are linked to the executable, bpf-fancy. + Note: The syntax <executable>-y is not permitted for userspace programs. + +5.3 Controlling compiler options for userspace programs +------------------------------------------------------- + + When compiling userspace programs, it is possible to set specific flags. + The programs will always be compiled utilising $(CC) passed + the options specified in $(KBUILD_USERCFLAGS). + To set flags that will take effect for all userspace programs created + in that Makefile, use the variable userccflags. + + Example:: + + # samples/seccomp/Makefile + userccflags += -I usr/include + + To set specific flags for a single file the following construction + is used: + + Example:: + + bpf-helper-userccflags += -I user/include + + It is also possible to specify additional options to the linker. + + Example:: + + # net/bpfilter/Makefile + bpfilter_umh-userldflags += -static + + When linking bpfilter_umh, it will be passed the extra option -static. + +5.4 When userspace programs are actually built +---------------------------------------------- + + Same as "When host programs are actually built". + +6 Kbuild clean infrastructure ============================= "make clean" deletes most generated files in the obj tree where the kernel @@ -790,7 +877,7 @@ is not operational at that point. Note 2: All directories listed in core-y, libs-y, drivers-y and net-y will be visited during "make clean". -6 Architecture Makefiles +7 Architecture Makefiles ======================== The top level Makefile sets up the environment and does the preparation, @@ -820,10 +907,10 @@ When kbuild executes, the following steps are followed (roughly): - Preparing initrd images and the like -6.1 Set variables to tweak the build to the architecture +7.1 Set variables to tweak the build to the architecture -------------------------------------------------------- - LDFLAGS + KBUILD_LDFLAGS Generic $(LD) options Flags used for all invocations of the linker. @@ -832,7 +919,7 @@ When kbuild executes, the following steps are followed (roughly): Example:: #arch/s390/Makefile - LDFLAGS := -m elf_s390 + KBUILD_LDFLAGS := -m elf_s390 Note: ldflags-y can be used to further customise the flags used. See chapter 3.7. @@ -967,7 +1054,7 @@ When kbuild executes, the following steps are followed (roughly): KBUILD_VMLINUX_LIBS together specify all the object files used to link vmlinux. -6.2 Add prerequisites to archheaders +7.2 Add prerequisites to archheaders ------------------------------------ The archheaders: rule is used to generate header files that @@ -977,7 +1064,7 @@ When kbuild executes, the following steps are followed (roughly): architecture itself. -6.3 Add prerequisites to archprepare +7.3 Add prerequisites to archprepare ------------------------------------ The archprepare: rule is used to list prerequisites that need to be @@ -995,7 +1082,7 @@ When kbuild executes, the following steps are followed (roughly): generating offset header files. -6.4 List directories to visit when descending +7.4 List directories to visit when descending --------------------------------------------- An arch Makefile cooperates with the top Makefile to define variables @@ -1030,7 +1117,7 @@ When kbuild executes, the following steps are followed (roughly): drivers-$(CONFIG_OPROFILE) += arch/sparc64/oprofile/ -6.5 Architecture-specific boot images +7.5 Architecture-specific boot images ------------------------------------- An arch Makefile specifies goals that take the vmlinux file, compress @@ -1085,7 +1172,7 @@ When kbuild executes, the following steps are followed (roughly): When "make" is executed without arguments, bzImage will be built. -6.6 Building non-kbuild targets +7.6 Building non-kbuild targets ------------------------------- extra-y @@ -1108,7 +1195,7 @@ When kbuild executes, the following steps are followed (roughly): In this example, extra-y is used to list object files that shall be built, but shall not be linked as part of built-in.a. -6.7 Commands useful for building a boot image +7.7 Commands useful for building a boot image --------------------------------------------- Kbuild provides a few macros that are useful when building a @@ -1211,7 +1298,7 @@ When kbuild executes, the following steps are followed (roughly): targets += $(dtb-y) DTC_FLAGS ?= -p 1024 -6.8 Custom kbuild commands +7.8 Custom kbuild commands -------------------------- When kbuild is executing with KBUILD_VERBOSE=0, then only a shorthand @@ -1241,7 +1328,7 @@ When kbuild executes, the following steps are followed (roughly): will be displayed with "make KBUILD_VERBOSE=0". -6.9 Preprocessing linker scripts +7.9 Preprocessing linker scripts -------------------------------- When the vmlinux image is built, the linker script @@ -1274,7 +1361,7 @@ When kbuild executes, the following steps are followed (roughly): The kbuild infrastructure for `*lds` files is used in several architecture-specific files. -6.10 Generic header files +7.10 Generic header files ------------------------- The directory include/asm-generic contains the header files @@ -1283,7 +1370,7 @@ When kbuild executes, the following steps are followed (roughly): to list the file in the Kbuild file. See "7.2 generic-y" for further info on syntax etc. -6.11 Post-link pass +7.11 Post-link pass ------------------- If the file arch/xxx/Makefile.postlink exists, this makefile @@ -1299,7 +1386,7 @@ When kbuild executes, the following steps are followed (roughly): For example, powerpc uses this to check relocation sanity of the linked vmlinux file. -7 Kbuild syntax for exported headers +8 Kbuild syntax for exported headers ------------------------------------ The kernel includes a set of headers that is exported to userspace. @@ -1319,14 +1406,14 @@ A Kbuild file may be defined under arch/<arch>/include/uapi/asm/ and arch/<arch>/include/asm/ to list asm files coming from asm-generic. See subsequent chapter for the syntax of the Kbuild file. -7.1 no-export-headers +8.1 no-export-headers --------------------- no-export-headers is essentially used by include/uapi/linux/Kbuild to avoid exporting specific headers (e.g. kvm.h) on architectures that do not support it. It should be avoided as much as possible. -7.2 generic-y +8.2 generic-y ------------- If an architecture uses a verbatim copy of a header from @@ -1356,7 +1443,7 @@ See subsequent chapter for the syntax of the Kbuild file. #include <asm-generic/termios.h> -7.3 generated-y +8.3 generated-y --------------- If an architecture generates other header files alongside generic-y @@ -1370,7 +1457,7 @@ See subsequent chapter for the syntax of the Kbuild file. #arch/x86/include/asm/Kbuild generated-y += syscalls_32.h -7.4 mandatory-y +8.4 mandatory-y --------------- mandatory-y is essentially used by include/(uapi/)asm-generic/Kbuild @@ -1380,7 +1467,7 @@ See subsequent chapter for the syntax of the Kbuild file. in arch/$(ARCH)/include/(uapi/)/asm, Kbuild will automatically generate a wrapper of the asm-generic one. -8 Kbuild Variables +9 Kbuild Variables ================== The top Makefile exports the following variables: @@ -1438,8 +1525,8 @@ The top Makefile exports the following variables: command. -9 Makefile language -=================== +10 Makefile language +==================== The kernel Makefiles are designed to be run with GNU Make. The Makefiles use only the documented features of GNU Make, but they do use many @@ -1458,7 +1545,7 @@ time the left-hand side is used. There are some cases where "=" is appropriate. Usually, though, ":=" is the right choice. -10 Credits +11 Credits ========== - Original version made by Michael Elizabeth Chastain, <mailto:mec@shout.net> @@ -1466,7 +1553,7 @@ is the right choice. - Updates by Sam Ravnborg <sam@ravnborg.org> - Language QA by Jan Engelhardt <jengelh@gmx.de> -11 TODO +12 TODO ======= - Describe how kbuild supports shipped files with _shipped. diff --git a/Documentation/kbuild/modules.rst b/Documentation/kbuild/modules.rst index e0b45a257f21..a45cccff467d 100644 --- a/Documentation/kbuild/modules.rst +++ b/Documentation/kbuild/modules.rst @@ -528,18 +528,6 @@ build. will then do the expected and compile both modules with full knowledge of symbols from either module. - Use an extra Module.symvers file - When an external module is built, a Module.symvers file - is generated containing all exported symbols which are - not defined in the kernel. To get access to symbols - from bar.ko, copy the Module.symvers file from the - compilation of bar.ko to the directory where foo.ko is - built. During the module build, kbuild will read the - Module.symvers file in the directory of the external - module, and when the build is finished, a new - Module.symvers file is created containing the sum of - all symbols defined and not part of the kernel. - Use "make" variable KBUILD_EXTRA_SYMBOLS If it is impractical to add a top-level kbuild file, you can assign a space separated list @@ -5,8 +5,6 @@ # mainmenu "Linux/$(ARCH) $(KERNELVERSION) Kernel Configuration" -comment "Compiler: $(CC_VERSION_TEXT)" - source "scripts/Kconfig.include" source "init/Kconfig" @@ -11,9 +11,12 @@ NAME = Kleptomaniac Octopus # Comments in this file are targeted only to the developer, do not # expect to learn how to build the kernel reading this file. +$(if $(filter __%, $(MAKECMDGOALS)), \ + $(error targets prefixed with '__' are only for internal use)) + # That's our default target when none is given on the command line -PHONY := _all -_all: +PHONY := __all +__all: # We are using a recursive build, so we need to do a little thinking # to get the ordering right. @@ -157,12 +160,14 @@ MAKEFLAGS += --include-dir=$(abs_srctree) need-sub-make := 1 endif +this-makefile := $(lastword $(MAKEFILE_LIST)) + ifneq ($(filter 3.%,$(MAKE_VERSION)),) # 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x # We need to invoke sub-make to avoid implicit rules in the top Makefile. need-sub-make := 1 # Cancel implicit rules for this Makefile. -$(lastword $(MAKEFILE_LIST)): ; +$(this-makefile): ; endif export abs_srctree abs_objtree @@ -170,13 +175,13 @@ export sub_make_done := 1 ifeq ($(need-sub-make),1) -PHONY += $(MAKECMDGOALS) sub-make +PHONY += $(MAKECMDGOALS) __sub-make -$(filter-out _all sub-make $(lastword $(MAKEFILE_LIST)), $(MAKECMDGOALS)) _all: sub-make +$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make @: # Invoke a second make in the output directory, passing relevant variables -sub-make: +__sub-make: $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS) endif # need-sub-make @@ -213,6 +218,9 @@ ifeq ("$(origin M)", "command line") KBUILD_EXTMOD := $(M) endif +$(if $(word 2, $(KBUILD_EXTMOD)), \ + $(error building multiple external modules is not supported)) + export KBUILD_CHECKSRC KBUILD_EXTMOD extmod-prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/) @@ -321,7 +329,7 @@ ifdef mixed-build PHONY += $(MAKECMDGOALS) __build_one_by_one -$(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one +$(MAKECMDGOALS): __build_one_by_one @: __build_one_by_one: @@ -406,9 +414,12 @@ else HOSTCC = gcc HOSTCXX = g++ endif -KBUILD_HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \ - -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS) \ - $(HOSTCFLAGS) + +export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ + -O2 -fomit-frame-pointer -std=gnu89 +export KBUILD_USERLDFLAGS := + +KBUILD_HOSTCFLAGS := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS) KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS) KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS) @@ -447,6 +458,26 @@ PYTHON = python PYTHON3 = python3 CHECK = sparse BASH = bash +GZIP = gzip +BZIP2 = bzip2 +LZOP = lzop +LZMA = lzma +LZ4 = lz4c +XZ = xz + +# GZIP, BZIP2, LZOP env vars are used by the tools. Support them as the command +# line interface, but use _GZIP, _BZIP2, _LZOP internally. +_GZIP := $(GZIP) +_BZIP2 := $(BZIP2) +_LZOP := $(LZOP) + +# Reset GZIP, BZIP2, LZOP in this Makefile +override GZIP= +override BZIP2= +override LZOP= + +# Reset GZIP, BZIP2, LZOP in recursive invocations +MAKEOVERRIDES += GZIP= BZIP2= LZOP= CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \ -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF) @@ -495,6 +526,7 @@ CLANG_FLAGS := export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC export CPP AR NM STRIP OBJCOPY OBJDUMP OBJSIZE READELF PAHOLE LEX YACC AWK INSTALLKERNEL export PERL PYTHON PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX +export _GZIP _BZIP2 _LZOP LZMA LZ4 XZ export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS @@ -593,12 +625,12 @@ else #!config-build # targets and others. In general all targets except *config targets. # If building an external module we do not care about the all: rule -# but instead _all depend on modules +# but instead __all depend on modules PHONY += all ifeq ($(KBUILD_EXTMOD),) -_all: all +__all: all else -_all: modules +__all: modules endif # Decide whether to build built-in, modular, or both. @@ -608,19 +640,15 @@ KBUILD_MODULES := KBUILD_BUILTIN := 1 # If we have only "make modules", don't compile built-in objects. -# When we're building modules with modversions, we need to consider -# the built-in objects during the descend as well, in order to -# make sure the checksums are up to date before we record them. - ifeq ($(MAKECMDGOALS),modules) - KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1) + KBUILD_BUILTIN := endif # If we have "make <whatever> modules", compile modules # in addition to whatever we do anyway. # Just "make" or "make all" shall build modules as well -ifneq ($(filter all _all modules nsdeps,$(MAKECMDGOALS)),) +ifneq ($(filter all modules nsdeps,$(MAKECMDGOALS)),) KBUILD_MODULES := 1 endif @@ -636,13 +664,11 @@ endif ifeq ($(KBUILD_EXTMOD),) # Objects we will link into vmlinux / subdirs we need to visit -init-y := init/ +core-y := init/ usr/ drivers-y := drivers/ sound/ drivers-$(CONFIG_SAMPLES) += samples/ -net-y := net/ +drivers-y += net/ virt/ libs-y := lib/ -core-y := usr/ -virt-y := virt/ endif # KBUILD_EXTMOD # The all: target is the default when no target is given on the @@ -695,7 +721,7 @@ $(KCONFIG_CONFIG): # This exploits the 'multi-target pattern rule' trick. # The syncconfig should be executed only once to make all the targets. # (Note: use the grouped target '&:' when we bump to GNU Make 4.3) -%/auto.conf %/auto.conf.cmd: $(KCONFIG_CONFIG) +%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG) $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig else # !may-sync-config # External modules and some install targets need include/generated/autoconf.h @@ -814,6 +840,12 @@ DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \ $(call cc-option,-fno-var-tracking) endif +ifdef CONFIG_DEBUG_INFO_COMPRESSED +DEBUG_CFLAGS += -gz=zlib +KBUILD_AFLAGS += -Wa,--compress-debug-sections=zlib +KBUILD_LDFLAGS += --compress-debug-sections=zlib +endif + KBUILD_CFLAGS += $(DEBUG_CFLAGS) export DEBUG_CFLAGS @@ -950,6 +982,10 @@ ifeq ($(CONFIG_RELR),y) LDFLAGS_vmlinux += --pack-dyn-relocs=relr endif +# Align the bit size of userspace programs with the kernel +KBUILD_USERCFLAGS += $(filter -m32 -m64, $(KBUILD_CFLAGS)) +KBUILD_USERLDFLAGS += $(filter -m32 -m64, $(KBUILD_CFLAGS)) + # make the checker run with the right architecture CHECKFLAGS += --arch=$(ARCH) @@ -1011,10 +1047,10 @@ export mod_strip_cmd mod_compress_cmd = true ifdef CONFIG_MODULE_COMPRESS ifdef CONFIG_MODULE_COMPRESS_GZIP - mod_compress_cmd = gzip -n -f + mod_compress_cmd = $(_GZIP) -n -f endif # CONFIG_MODULE_COMPRESS_GZIP ifdef CONFIG_MODULE_COMPRESS_XZ - mod_compress_cmd = xz -f + mod_compress_cmd = $(XZ) -f endif # CONFIG_MODULE_COMPRESS_XZ endif # CONFIG_MODULE_COMPRESS export mod_compress_cmd @@ -1049,34 +1085,33 @@ export MODULES_NSDEPS := $(extmod-prefix)modules.nsdeps ifeq ($(KBUILD_EXTMOD),) core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/ -vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \ +vmlinux-dirs := $(patsubst %/,%,$(filter %/, \ $(core-y) $(core-m) $(drivers-y) $(drivers-m) \ - $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y))) + $(libs-y) $(libs-m))) vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \ - $(patsubst %/,%,$(filter %/, $(init-) $(core-) \ - $(drivers-) $(net-) $(libs-) $(virt-)))) + $(patsubst %/,%,$(filter %/, $(core-) \ + $(drivers-) $(libs-)))) + +subdir-modorder := $(addsuffix modules.order,$(filter %/, \ + $(core-y) $(core-m) $(libs-y) $(libs-m) \ |