summaryrefslogtreecommitdiff
path: root/Makefile
AgeCommit message (Collapse)AuthorFilesLines
2019-10-11Linux 5.3.6v5.3.6Greg Kroah-Hartman1-1/+1
2019-10-07Linux 5.3.5v5.3.5Greg Kroah-Hartman1-1/+1
2019-10-07kbuild: Do not enable -Wimplicit-fallthrough for clang for nowNathan Chancellor1-3/+5
[ Upstream commit e2079e93f562c7f7a030eb7642017ee5eabaaa10 ] This functionally reverts commit bfd77145f35c ("Makefile: Convert -Wimplicit-fallthrough=3 to just -Wimplicit-fallthrough for clang"). clang enabled support for -Wimplicit-fallthrough in C in r369414 [1], which causes a lot of warnings when building the kernel for two reasons: 1. Clang does not support the /* fall through */ comments. There seems to be a general consensus in the LLVM community that this is not something they want to support. Joe Perches wrote a script to convert all of the comments to a "fallthrough" keyword that will be added to compiler_attributes.h [2] [3], which catches the vast majority of the comments. There doesn't appear to be any consensus in the kernel community when to do this conversion. 2. Clang and GCC disagree about falling through to final case statements with no content or cases that simply break: https://godbolt.org/z/c8csDu This difference contributes at least 50 warnings in an allyesconfig build for x86, not considering other architectures. This difference will need to be discussed to see which compiler is right [4] [5]. [1]: https://github.com/llvm/llvm-project/commit/1e0affb6e564b7361b0aadb38805f26deff4ecfc [2]: https://lore.kernel.org/lkml/61ddbb86d5e68a15e24ccb06d9b399bbf5ce2da7.camel@perches.com/ [3]: https://lore.kernel.org/lkml/1d2830aadbe9d8151728a7df5b88528fc72a0095.1564549413.git.joe@perches.com/ [4]: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91432 [5]: https://github.com/ClangBuiltLinux/linux/issues/636 Given these two problems need discussion and coordination, do not enable -Wimplicit-fallthrough with clang right now. Add a comment to explain what is going on as well. This commit should be reverted once these two issues are fully flushed out and resolved. Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Acked-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05Linux 5.3.4v5.3.4Greg Kroah-Hartman1-1/+1
2019-10-05Linux 5.3.3v5.3.3Greg Kroah-Hartman1-1/+1
2019-10-05Revert "Linux 5.3.2"Greg Kroah-Hartman1-1/+1
This reverts commit 9c30694424ee15cc30a23f92a913d5322b9e5bd2 That wasn't a 5.3.2 release, it was a 5.3.3 release, as the Makefile changed, but the text in the commit message didn't. So revert it, so we can do an "empty" 5.3.3 release, just to keep things working properly. Sorry for the noise :( Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-01Linux 5.3.2Greg Kroah-Hartman1-1/+1
2019-10-01Linux 5.3.2v5.3.2Greg Kroah-Hartman1-1/+1
2019-09-21Linux 5.3.1v5.3.1Greg Kroah-Hartman1-1/+1
2019-09-16Linux 5.3v5.3Linus Torvalds1-1/+1
2019-09-08Linux 5.3-rc8v5.3-rc8Linus Torvalds1-1/+1
2019-09-02Linux 5.3-rc7v5.3-rc7Linus Torvalds1-1/+1
2019-08-25Linux 5.3-rc6v5.3-rc6Linus Torvalds1-1/+1
2019-08-19Linux 5.3-rc5v5.3-rc5Linus Torvalds1-1/+1
2019-08-11Linux 5.3-rc4v5.3-rc4Linus Torvalds1-1/+1
2019-08-10Makefile: Convert -Wimplicit-fallthrough=3 to just -Wimplicit-fallthrough ↵Joe Perches1-1/+1
for clang A compilation -Wimplicit-fallthrough warning was enabled by commit a035d552a93b ("Makefile: Globally enable fall-through warning") Even though clang 10.0.0 does not currently support this warning without a patch, clang currently does not support a value for this option. Link: https://bugs.llvm.org/show_bug.cgi?id=39382 The gcc default for this warning is 3 so removing the =3 has no effect for gcc and enables the warning for patched versions of clang. Also remove the =3 from an existing use in a parisc Makefile: arch/parisc/math-emu/Makefile Signed-off-by: Joe Perches <joe@perches.com> Reviewed-and-tested-by: Nathan Chancellor <natechancellor@gmail.com> Cc: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-08-10Merge tag 'kbuild-fixes-v5.3-3' of ↵Linus Torvalds1-1/+12
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - revive single target %.ko - do not create built-in.a where it is unneeded - do not create modules.order where it is unneeded - show a warning if subdir-y/m is used to visit a module Makefile * tag 'kbuild-fixes-v5.3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: show hint if subdir-y/m is used to visit module Makefile kbuild: generate modules.order only in directories visited by obj-y/m kbuild: fix false-positive need-builtin calculation kbuild: revive single target %.ko
2019-08-09kbuild: show hint if subdir-y/m is used to visit module MakefileMasahiro Yamada1-1/+1
Since commit ff9b45c55b26 ("kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod"), a module is no longer built in the following pattern: [Makefile] subdir-y := some-module [some-module/Makefile] obj-m := some-module.o You cannot write Makefile this way in upstream because modules.order is not correctly generated. subdir-y is used to descend to a sub-directory that builds tools, device trees, etc. For external modules, the modules order does not matter. So, the Makefile above was known to work. I believe the Makefile should be re-written as follows: [Makefile] obj-m := some-module/ [some-module/Makefile] obj-m := some-module.o However, people will have no idea if their Makefile suddenly stops working. In fact, I received questions from multiple people. Show a warning for a while if obj-m is specified in a Makefile visited by subdir-y or subdir-m. I touched the %/ rule to avoid false-positive warnings for the single target. Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Tom Stonecypher <thomas.edwardx.stonecypher@intel.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
2019-08-09kbuild: revive single target %.koMasahiro Yamada1-0/+11
I removed the single target %.ko in commit ff9b45c55b26 ("kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod") because the modpost stage does not work reliably. For instance, the module dependency, modversion, etc. do not work if we lack symbol information from the other modules. Yet, some people still want to build only one module in their interest, and it may be still useful if it is used within those limitations. Fixes: ff9b45c55b26 ("kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod") Reported-by: Don Brace <don.brace@microsemi.com> Reported-by: Arend Van Spriel <arend.vanspriel@broadcom.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-08-08kbuild: add OBJSIZE variable for the size toolVasily Gorbik1-3/+4
Define and export OBJSIZE variable for "size" tool from binutils to be used in architecture specific Makefiles (naming the variable just "SIZE" would be too risky). In particular this tool is useful to perform checks that early boot code is not using bss section (which might have not been zeroed yet or intersects with initrd or other files boot loader might have put right after the linux kernel). Link: http://lkml.kernel.org/r/patch-1.thread-2257a1.git-188f5a3d81d5.your-ad-here.call-01565088755-ext-5120@work.hours Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-05Linux 5.3-rc3v5.3-rc3Linus Torvalds1-1/+1
2019-07-30kbuild: initialize CLANG_FLAGS correctly in the top MakefileMasahiro Yamada1-1/+2
CLANG_FLAGS is initialized by the following line: CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%)) ..., which is run only when CROSS_COMPILE is set. Some build targets (bindeb-pkg etc.) recurse to the top Makefile. When you build the kernel with Clang but without CROSS_COMPILE, the same compiler flags such as -no-integrated-as are accumulated into CLANG_FLAGS. If you run 'make CC=clang' and then 'make CC=clang bindeb-pkg', Kbuild will recompile everything needlessly due to the build command change. Fix this by correctly initializing CLANG_FLAGS. Fixes: 238bcbc4e07f ("kbuild: consolidate Clang compiler flags") Cc: <stable@vger.kernel.org> # v5.0+ Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Acked-by: Nick Desaulniers <ndesaulniers@google.com>
2019-07-28Linux 5.3-rc2v5.3-rc2Linus Torvalds1-1/+1
2019-07-26Makefile: Globally enable fall-through warningGustavo A. R. Silva1-0/+3
Now that all the fall-through warnings have been addressed in the kernel, enable the fall-through warning globally. Also, update the deprecated.rst file to include implicit fall-through as 'deprecated' so people can be pointed to a single location for justification. Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Kees Cook <keescook@chromium.org> Cc: linux-kbuild@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
2019-07-22Linus 5.3-rc1v5.3-rc1Linus Torvalds1-2/+2
2019-07-20kbuild: add -fcf-protection=none when using retpoline flagsSeth Forshee1-0/+6
The gcc -fcf-protection=branch option is not compatible with -mindirect-branch=thunk-extern. The latter is used when CONFIG_RETPOLINE is selected, and this will fail to build with a gcc which has -fcf-protection=branch enabled by default. Adding -fcf-protection=none when building with retpoline enabled prevents such build failures. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-17kbuild: remove 'prepare1' targetMasahiro Yamada1-5/+3
Now that there is no rule for 'prepare1', it can go away. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-17kbuild: create *.mod with full directory path and remove MODVERDIRMasahiro Yamada1-17/+3
While descending directories, Kbuild produces objects for modules, but do not link final *.ko files; it is done in the modpost. To keep track of modules, Kbuild creates a *.mod file in $(MODVERDIR) for every module it is building. Some post-processing steps read the necessary information from *.mod files. This avoids descending into directories again. This mechanism was introduced in 2003 or so. Later, commit 551559e13af1 ("kbuild: implement modules.order") added modules.order. So, we can simply read it out to know all the modules with directory paths. This is easier than parsing the first line of *.mod files. $(MODVERDIR) has a flat directory structure, that is, *.mod files are named only with base names. This is based on the assumption that the module name is unique across the tree. This assumption is really fragile. Stephen Rothwell reported a race condition caused by a module name conflict: https://lkml.org/lkml/2019/5/13/991 In parallel building, two different threads could write to the same $(MODVERDIR)/*.mod simultaneously. Non-unique module names are the source of all kind of troubles, hence commit 3a48a91901c5 ("kbuild: check uniqueness of module names") introduced a new checker script. However, it is still fragile in the build system point of view because this race happens before scripts/modules-check.sh is invoked. If it happens again, the modpost will emit unclear error messages. To fix this issue completely, create *.mod with full directory path so that two threads never attempt to write to the same file. $(MODVERDIR) is no longer needed. Since modules with directory paths are listed in modules.order, Kbuild is still able to find *.mod files without additional descending. I also killed cmd_secanalysis; scripts/mod/sumversion.c computes MD4 hash for modules with MODULE_VERSION(). When CONFIG_DEBUG_SECTION_MISMATCH=y, it occurs not only in the modpost stage, but also during directory descending, where sumversion.c may parse stale *.mod files. It would emit 'No such file or directory' warning when an object consisting a module is renamed, or when a single-obj module is turned into a multi-obj module or vice versa. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Nicolas Pitre <nico@fluxnic.net>
2019-07-17kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.modMasahiro Yamada1-2/+0
Towards the goal of removing MODVERDIR, read out modules.order to get the list of modules to be processed. This is simpler than parsing *.mod files in $(MODVERDIR). For external modules, $(KBUILD_EXTMOD)/modules.order should be read. I removed the single target %.ko from the top Makefile. To make sure modpost works correctly, vmlinux and the other modules must be built. You cannot build a particular .ko file alone. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-17kbuild: get rid of kernel/ prefix from in-tree modules.{order,builtin}Masahiro Yamada1-2/+2
Removing the 'kernel/' prefix will make our life easier because we can simply do 'cat modules.order' to get all built modules with full paths. Currently, we parse the first line of '*.mod' files in $(MODVERDIR). Since we have duplicated functionality here, I plan to remove MODVERDIR entirely. In fact, modules.order is generated also for external modules in a broken format. It adds the 'kernel/' prefix to the absolute path of the module, like this: kernel//path/to/your/external/module/foo.ko This is fine for now since modules.order is not used for external modules. However, I want to sanitize the format everywhere towards the goal of removing MODVERDIR. We cannot change the format of installed module.{order,builtin}. So, 'make modules_install' will add the 'kernel/' prefix while copying them to $(MODLIB)/. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-17kbuild: do not create empty modules.order in the prepare stageMasahiro Yamada1-2/+2
Currently, $(objtree)/modules.order is touched in two places. In the 'prepare0' rule, scripts/Makefile.build creates an empty modules.order while processing 'obj=.' In the 'modules' rule, the top-level Makefile overwrites it with the correct list of modules. While this might be a good side-effect that modules.order is made empty every time (probably this is not intended functionality), I personally do not like this behavior. Create modules.order only when it is sensible to do so. This avoids creating the following pointless files: scripts/basic/modules.order scripts/dtc/modules.order scripts/gcc-plugins/modules.order scripts/genksyms/modules.order scripts/mod/modules.order scripts/modules.order scripts/selinux/genheaders/modules.order scripts/selinux/mdp/modules.order scripts/selinux/modules.order Going forward, $(objtree)/modules.order lists the modules that was built in the last successful build. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-17kbuild: remove tag files by distclean instead of mrproperMasahiro Yamada1-1/+10
It takes somewhat long time to generate these tag files. Keep such precious files until we run 'make distclean'. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-17kbuild: add --hash-style= and --build-id unconditionallyMasahiro Yamada1-4/+2
As commit 1e0221374e30 ("mips: vdso: drop unnecessary cc-ldoption") explained, these flags are supported by the minimal required version of binutils. They are supported by ld.lld too. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
2019-07-13Merge tag 'kbuild-v5.3' of ↵Linus Torvalds1-51/+66
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - remove headers_{install,check}_all targets - remove unreasonable 'depends on !UML' from CONFIG_SAMPLES - re-implement 'make headers_install' more cleanly - add new header-test-y syntax to compile-test headers - compile-test exported headers to ensure they are compilable in user-space - compile-test headers under include/ to ensure they are self-contained - remove -Waggregate-return, -Wno-uninitialized, -Wno-unused-value flags - add -Werror=unknown-warning-option for Clang - add 128-bit built-in types support to genksyms - fix missed rebuild of modules.builtin - propagate 'No space left on device' error in fixdep to Make - allow Clang to use its integrated assembler - improve some coccinelle scripts - add a new flag KBUILD_ABS_SRCTREE to request Kbuild to use absolute path for $(srctree). - do not ignore errors when compression utility is missing - misc cleanups * tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (49 commits) kbuild: use -- separater intead of $(filter-out ...) for cc-cross-prefix kbuild: Inform user to pass ARCH= for make mrproper kbuild: fix compression errors getting ignored kbuild: add a flag to force absolute path for srctree kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctree kbuild: remove src and obj from the top Makefile scripts/tags.sh: remove unused environment variables from comments scripts/tags.sh: drop SUBARCH support for ARM kbuild: compile-test kernel headers to ensure they are self-contained kheaders: include only headers into kheaders_data.tar.xz kheaders: remove meaningless -R option of 'ls' kbuild: support header-test-pattern-y kbuild: do not create wrappers for header-test-y kbuild: compile-test exported headers to ensure they are self-contained init/Kconfig: add CONFIG_CC_CAN_LINK kallsyms: exclude kasan local symbols on s390 kbuild: add more hints about SUBDIRS replacement coccinelle: api/stream_open: treat all wait_.*() calls as blocking coccinelle: put_device: Add a cast to an expression for an assignment coccinelle: put_device: Adjust a message construction ...
2019-07-10kbuild: Inform user to pass ARCH= for make mrproperGeert Uytterhoeven1-1/+1
When cross-compiling an out-of-tree build with an unclean source tree directory, the build fails with: /path/to/kernel/source/tree is not clean, please run 'make mrproper' in the '/path/to/kernel/source/tree' directory. However, doing so does not fix the problem, as "make mrproper" now requires passing the target architecture to the make command, else it won't remove $(srctree)/arch/$(SRCARCH)/include/generated. "git ls-files -o" doesn't give a clue, as it doesn't list (empty) directories, only files. Improve usability by including the ARCH= option in the error output. Fixes: a788b2ed81ab ("kbuild: check arch/$(SRCARCH)/include/generated before out-of-tree build") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-10kbuild: add a flag to force absolute path for srctreeMasahiro Yamada1-0/+4
In old days, Kbuild always used an absolute path for $(srctree). Since commit 890676c65d69 ("kbuild: Use relative path when building in the source tree"), $(srctree) is '.' when O= was not passed from the command line. Yet, using absolute paths is useful in some cases even without O=, for instance, to create a cscope file with absolute path tags. 'O=.' was known to work as a workaround to force Kbuild to use absolute paths even when you are building in the source tree. Since commit 25b146c5b8ce ("kbuild: allow Kbuild to start from any directory"), Kbuild is too clever to be tricked. Even if you pass 'O=.' Kbuild notices you are building in the source tree, then use '.' for $(srctree). So, 'make O=. cscope' is no help to create absolute path tags. We cannot force one or the other according to commit e93bc1a0cab3 ("Revert "kbuild: specify absolute paths for cscope""). Both of relative path and absolute path have pros and cons. This commit adds a new flag KBUILD_ABS_SRCTREE to allow users to choose the absolute path for $(srctree). 'make KBUILD_ABS_SRCTREE=1 cscope' will work as a replacement of 'make O=. cscope'. Reported-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-10kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctreeMasahiro Yamada1-11/+8
Commit 25b146c5b8ce ("kbuild: allow Kbuild to start from any directory") deprecated KBUILD_SRCTREE. It is only used in tools/testing/selftest/ to distinguish out-of-tree build. Replace it with a new boolean flag, building_out_of_srctree. I also replaced the conditional ($(srctree),.) because the next commit will allow an absolute path to be used for $(srctree) even when building in the source tree. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-10kbuild: remove src and obj from the top MakefileMasahiro Yamada1-6/+3
Replace $(src) and $(obj) with $(srctree) and $(objtree), respectively. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-09kbuild: compile-test kernel headers to ensure they are self-containedMasahiro Yamada1-0/+1
The headers in include/ are globally used in the kernel source tree to provide common APIs. They are included from external modules, too. It will be useful to make as many headers self-contained as possible so that we do not have to rely on a specific include order. There are more than 4000 headers in include/. In my rough analysis, 70% of them are already self-contained. With efforts, most of them can be self-contained. For now, we must exclude more than 1000 headers just because they cannot be compiled as standalone units. I added them to header-test-. The blacklist was mostly generated by a script, so the reason of the breakage should be checked later. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
2019-07-09kbuild: do not create wrappers for header-test-yMasahiro Yamada1-1/+0
header-test-y does not work with headers in sub-directories. For example, you may want to write a Makefile, like this: include/linux/Kbuild: header-test-y += mtd/nand.h This entry will create a wrapper include/linux/mtd/nand.hdrtest.c with the following content: #include "mtd/nand.h" To make this work, we need to add $(srctree)/include/linux to the header search path. It would be tedious to add ccflags-y. Instead, we could change the *.hdrtest.c rule to wrap: #include "nand.h" This works for in-tree build since #include "..." searches in the relative path from the header with this directive. For O=... build, we need to add $(srctree)/include/linux/mtd to the header search path, which will be even more tedious. After all, I thought it would be handier to compile headers directly without creating wrappers. I added a new build rule to compile %.h into %.h.s The target is %.h.s instead of %.h.o because it is slightly faster. Also, as for GCC, an empty assembly is smaller than an empty object. I wrote the build rule: $(CC) $(c_flags) -S -o $@ -x c /dev/null -include $< instead of: $(CC) $(c_flags) -S -o $@ -x c $< Both work fine with GCC, but the latter is bad for Clang. This comes down to the difference in the -Wunused-function policy. GCC does not warn about unused 'static inline' functions at all. Clang does not warn about the ones in included headers, but does about the ones in the source. So, we should handle headers as headers, not as source files. In fact, this has been hidden since commit abb2ea7dfd82 ("compiler, clang: suppress warning for unused static inline functions"), but we should not rely on that. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Tested-by: Jani Nikula <jani.nikula@intel.com>
2019-07-08kbuild: compile-test exported headers to ensure they are self-containedMasahiro Yamada1-1/+1
Multiple people have suggested compile-testing UAPI headers to ensure they can be really included from user-space. "make headers_check" is obviously not enough to catch bugs, and we often leak unresolved references to user-space. Use the new header-test-y syntax to implement it. Please note exported headers are compile-tested with a completely different set of compiler flags. The header search path is set to $(objtree)/usr/include since exported headers should not include unexported ones. We use -std=gnu89 for the kernel space since the kernel code highly depends on GNU extensions. On the other hand, UAPI headers should be written in more standardized C, so they are compiled with -std=c90. This will emit errors if C++ style comments, the keyword 'inline', etc. are used. Please use C style comments (/* ... */), '__inline__', etc. in UAPI headers. There is additional compiler requirement to enable this test because many of UAPI headers include <stdlib.h>, <sys/ioctl.h>, <sys/time.h>, etc. directly or indirectly. You cannot use kernel.org pre-built toolchains [1] since they lack <stdlib.h>. I reused CONFIG_CC_CAN_LINK to check the system header availability. The intention is slightly different, but a compiler that can link userspace programs provide system headers. For now, a lot of headers need to be excluded because they cannot be compiled standalone, but this is a good start point. [1] https://mirrors.edge.kernel.org/pub/tools/crosstool/index.html Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
2019-07-08Linux 5.2v5.2Linus Torvalds1-1/+1
2019-07-07kbuild: add more hints about SUBDIRS replacementMasahiro Yamada1-0/+7
Commit 0126be38d988 ("kbuild: announce removal of SUBDIRS if used") added a hint about the 'SUBDIRS' replacement, but it was not clear enough. Multiple people sent me similar questions, patches. For instance, https://lkml.org/lkml/2019/1/17/456 I did not mean to use M= for building a subdirectory in the kernel tree. From commit 669efc76b317 ("net: hns3: fix compile error"), people already (ab)use M=... to do that because it seems to work to some extent. Documentation/kbuild/kbuild.txt says M= and KBUILD_EXTMOD are used for building external modules. In fact, Kbuild supports the single target '%/' for this purpose, but this may not be noticed much. Kindly add more hints. Makefile:213: ================= WARNING ================ Makefile:214: 'SUBDIRS' will be removed after Linux 5.3 Makefile:215: Makefile:216: If you are building an individual subdirectory Makefile:217: in the kernel tree, you can do like this: Makefile:218: $ make path/to/dir/you/want/to/build/ Makefile:219: (Do not forget the trailing slash) Makefile:220: Makefile:221: If you are building an external module, Makefile:222: Please use 'M=' or 'KBUILD_EXTMOD' instead Makefile:223: ========================================== Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2019-07-04kbuild: Add ability to test Clang's integrated assemblerNathan Chancellor1-0/+2
There are some people interested in experimenting with Clang's integrated assembler. To make it easy to do so without source modification, allow the user to specify 'AS=clang' as part of the make command to avoid adding '-no-integrated-as' to the {A,C}FLAGS. Link: https://github.com/ClangBuiltLinux/linux/issues/577 Suggested-by: Dmitry Golovin <dima@golovin.in> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-01kbuild: split modules.order build rule out of 'modules' targetMasahiro Yamada1-2/+4
modules.order is a real target. Split its build rule out like modules.builtin Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-01kbuild: fix missed rebuild of modules.builtinMasahiro Yamada1-4/+8
Unlike modules.order, modules.builtin is not rebuilt every time. Once modules.builtin is created, it will not be updated until auto.conf or tristate.conf is changed. So, it does not notice a change in Makefile, for example, the rename of modules. Kbuild must always descend into directories for modules.builtin too. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-30Linux 5.2-rc7v5.2-rc7Linus Torvalds1-2/+2
2019-06-23kbuild: Add -Werror=unknown-warning-option to CLANG_FLAGSNathan Chancellor1-0/+1
In commit ebcc5928c5d9 ("arm64: Silence gcc warnings about arch ABI drift"), the arm64 Makefile added -Wno-psabi to KBUILD_CFLAGS, which is a GCC only option so clang rightfully complains: warning: unknown warning option '-Wno-psabi' [-Wunknown-warning-option] https://clang.llvm.org/docs/DiagnosticsReference.html#wunknown-warning-option However, by default, this is merely a warning so the build happily goes on with a slew of these warnings in the process. Commit c3f0d0bc5b01 ("kbuild, LLVMLinux: Add -Werror to cc-option to support clang") worked around this behavior in cc-option by adding -Werror so that unknown flags cause an error. However, this all happens silently and when an unknown flag is added to the build unconditionally like -Wno-psabi, cc-option will always fail because there is always an unknown flag in the list of flags. This manifested as link time failures in the arm64 libstub because -fno-stack-protector didn't get added to KBUILD_CFLAGS. To avoid these weird cryptic failures in the future, make clang behave like gcc and immediately error when it encounters an unknown flag by adding -Werror=unknown-warning-option to CLANG_FLAGS. This can be added unconditionally for clang because it is supported by at least 3.0.0, according to godbolt [1] and 4.0.0, according to its documentation [2], which is far earlier than we typically support. [1]: https://godbolt.org/z/7F7rm3 [2]: https://releases.llvm.org/4.0.0/tools/clang/docs/DiagnosticsReference.html#wunknown-warning-option Link: https://github.com/ClangBuiltLinux/linux/issues/511 Link: https://github.com/ClangBuiltLinux/linux/issues/517 Suggested-by: Peter Smith <peter.smith@linaro.org> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-23Linux 5.2-rc6v5.2-rc6Linus Torvalds1-1/+1
2019-06-16Linux 5.2-rc5v5.2-rc5Linus Torvalds1-1/+1
generated by cgit v1.2.3 (git 2.39.0) at 2026-05-13 02:28:58 +0300