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2019-09-16Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "Although there isn't tonnes of code in terms of line count, there are a fair few headline features which I've noted both in the tag and also in the merge commits when I pulled everything together. The part I'm most pleased with is that we had 35 contributors this time around, which feels like a big jump from the usual small group of core arm64 arch developers. Hopefully they all enjoyed it so much that they'll continue to contribute, but we'll see. It's probably worth highlighting that we've pulled in a branch from the risc-v folks which moves our CPU topology code out to where it can be shared with others. Summary: - 52-bit virtual addressing in the kernel - New ABI to allow tagged user pointers to be dereferenced by syscalls - Early RNG seeding by the bootloader - Improve robustness of SMP boot - Fix TLB invalidation in light of recent architectural clarifications - Support for i.MX8 DDR PMU - Remove direct LSE instruction patching in favour of static keys - Function error injection using kprobes - Support for the PPTT "thread" flag introduced by ACPI 6.3 - Move PSCI idle code into proper cpuidle driver - Relaxation of implicit I/O memory barriers - Build with RELR relocations when toolchain supports them - Numerous cleanups and non-critical fixes" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (114 commits) arm64: remove __iounmap arm64: atomics: Use K constraint when toolchain appears to support it arm64: atomics: Undefine internal macros after use arm64: lse: Make ARM64_LSE_ATOMICS depend on JUMP_LABEL arm64: asm: Kill 'asm/atomic_arch.h' arm64: lse: Remove unused 'alt_lse' assembly macro arm64: atomics: Remove atomic_ll_sc compilation unit arm64: avoid using hard-coded registers for LSE atomics arm64: atomics: avoid out-of-line ll/sc atomics arm64: Use correct ll/sc atomic constraints jump_label: Don't warn on __exit jump entries docs/perf: Add documentation for the i.MX8 DDR PMU perf/imx_ddr: Add support for AXI ID filtering arm64: kpti: ensure patched kernel text is fetched from PoU arm64: fix fixmap copy for 16K pages and 48-bit VA perf/smmuv3: Validate groups for global filtering perf/smmuv3: Validate group size arm64: Relax Documentation/arm64/tagged-pointers.rst arm64: kvm: Replace hardcoded '1' with SYS_PAR_EL1_F arm64: mm: Ignore spurious translation faults taken from the kernel ...
2019-09-15Linux 5.3Linus Torvalds
2019-09-08Linux 5.3-rc8Linus Torvalds
2019-09-02Linux 5.3-rc7Linus Torvalds
2019-08-25Linux 5.3-rc6Linus Torvalds
2019-08-18Linux 5.3-rc5Linus Torvalds
2019-08-11Linux 5.3-rc4Linus Torvalds
2019-08-10Makefile: Convert -Wimplicit-fallthrough=3 to just -Wimplicit-fallthrough ↵Joe Perches
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>
2019-08-09Merge tag 'kbuild-fixes-v5.3-3' of ↵Linus Torvalds
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
2019-08-10kbuild: show hint if subdir-y/m is used to visit module MakefileMasahiro Yamada
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>
2019-08-10kbuild: revive single target %.koMasahiro Yamada
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 Gorbik
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>
2019-08-05arm64: Add support for relocating the kernel with RELR relocationsPeter Collingbourne
RELR is a relocation packing format for relative relocations. The format is described in a generic-abi proposal: https://groups.google.com/d/topic/generic-abi/bX460iggiKg/discussion The LLD linker can be instructed to pack relocations in the RELR format by passing the flag --pack-dyn-relocs=relr. This patch adds a new config option, CONFIG_RELR. Enabling this option instructs the linker to pack vmlinux's relative relocations in the RELR format, and causes the kernel to apply the relocations at startup along with the RELA relocations. RELA relocations still need to be applied because the linker will emit RELA relative relocations if they are unrepresentable in the RELR format (i.e. address not a multiple of 2). Enabling CONFIG_RELR reduces the size of a defconfig kernel image with CONFIG_RANDOMIZE_BASE by 3.5MB/16% uncompressed, or 550KB/5% compressed (lz4). Signed-off-by: Peter Collingbourne <pcc@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-04Linux 5.3-rc3Linus Torvalds
2019-07-31kbuild: initialize CLANG_FLAGS correctly in the top MakefileMasahiro Yamada
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-rc2Linus Torvalds
2019-07-25Makefile: Globally enable fall-through warningGustavo A. R. Silva
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>
2019-07-21Linus 5.3-rc1Linus Torvalds
2019-07-20kbuild: add -fcf-protection=none when using retpoline flagsSeth Forshee
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>
2019-07-18kbuild: remove 'prepare1' targetMasahiro Yamada
Now that there is no rule for 'prepare1', it can go away. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-18kbuild: create *.mod with full directory path and remove MODVERDIRMasahiro Yamada
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>
2019-07-18kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.modMasahiro Yamada
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 Yamada
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 Yamada
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 Yamada
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 Yamada
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>
2019-07-12Merge tag 'kbuild-v5.3' of ↵Linus Torvalds
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 ...
2019-07-11kbuild: Inform user to pass ARCH= for make mrproperGeert Uytterhoeven
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>
2019-07-11kbuild: add a flag to force absolute path for srctreeMasahiro Yamada
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 $(srctree). 'make KBUILD_ABS_SRCTREE=1 cscope' will work as a replacement of 'make O=. cscope'. Reported-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-11kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctreeMasahiro Yamada
Commit 25b146c5b8ce ("kbuild: allow Kbuild to start from any directory") deprecated KBUILD_SRCTREE. It is only used in tools/testing/selftest/ to distinguish out-of-tree build. Replace it with a new boolean flag, building_out_of_srctree. I also replaced the conditional ($(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>
2019-07-11kbuild: remove src and obj from the top MakefileMasahiro Yamada
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 Yamada
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 Yamada
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 Yamada
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>
2019-07-07Linux 5.2Linus Torvalds
2019-07-08kbuild: add more hints about SUBDIRS replacementMasahiro Yamada
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 Chancellor
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 Yamada
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 Yamada
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-rc7Linus Torvalds
2019-06-24kbuild: Add -Werror=unknown-warning-option to CLANG_FLAGSNathan Chancellor
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>
2019-06-22Linux 5.2-rc6Linus Torvalds
2019-06-16Linux 5.2-rc5Linus Torvalds
2019-06-15kbuild: add support for ensuring headers are self-containedJani Nikula
Sometimes it's useful to be able to explicitly ensure certain headers remain self-contained, i.e. that they are compilable as standalone units, by including and/or forward declaring everything they depend on. Add special target header-test-y where individual Makefiles can add headers to be tested if CONFIG_HEADER_TEST is enabled. This will generate a dummy C file per header that gets built as part of extra-y. Signed-off-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-15kbuild: move hdr-inst shorthand to top MakefileMasahiro Yamada
Now that hdr-inst is used only in the top Makefile, move it there from scripts/Kbuild.include. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-15kbuild: re-implement Makefile.headersinst without recursionMasahiro Yamada
Since commit fcc8487d477a ("uapi: export all headers under uapi directories"), the headers in uapi directories are all exported by default although exceptional cases are still allowed by the syntax 'no-export-headers'. The traditional directory descending has been kept (in a somewhat hacky way), but it is actually unneeded. Get rid of it to simplify the code. Also, handle files one by one instead of the previous per-directory processing. This will emit much more log, but I like it. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-15kbuild: add 'headers' target to build up uapi headers in usr/includeMasahiro Yamada
In Linux build system, build targets and installation targets are separated. Examples are: - 'make vmlinux' -> 'make install' - 'make modules' -> 'make modules_install' - 'make dtbs' -> 'make dtbs_install' - 'make vdso' -> 'make vdso_install' The intention is to run the build targets under the normal privilege, then the installation targets under the root privilege since we need the write permission to the system directories. We have 'make headers_install' but the corresponding 'make headers' stage does not exist. The purpose of headers_install is to provide the kernel interface to C library. So, nobody would try to install headers to /usr/include directly. If 'sudo make INSTALL_HDR_PATH=/usr/include headers_install' were run, some build artifacts in the kernel tree would be owned by root because some of uapi headers are generated by 'uapi-asm-generic', 'archheaders' targets. Anyway, I believe it makes sense to split the header installation into two stages. [1] 'make headers' Process headers in uapi directories by scripts/headers_install.sh and copy them to usr/include [2] 'make headers_install' Copy '*.h' verbatim from usr/include to $(INSTALL_HDR_PATH)/include For the backward compatibility, 'headers_install' depends on 'headers'. Some samples expect uapi headers in usr/include. So, the 'headers' target is useful to build up them in the fixed location usr/include irrespective of INSTALL_HDR_PATH. Another benefit is to stop polluting the final destination with the time-stamp files '.install' and '.check'. Maybe you can see them in your toolchains. Lastly, my main motivation is to prepare for compile-testing uapi headers. To build something, we have to save an object and .*.cmd somewhere. The usr/include/ will be the work directory for that. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-15kbuild: build all prerequisites of headers_install simultaneouslyMasahiro Yamada
Currently, scripts/unifdef is compiled after scripts_basic, uapi-asm-generic, archheaders, and archscripts. The proper dependency is just scripts_basic. There is no problem to compile scripts/unifdef and other headers at the same time. Split scripts_unifdef out in order to allow more parallel building. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-15kbuild: remove build_unifdef target in scripts/MakefileMasahiro Yamada
Since commit 2aedcd098a94 ("kbuild: suppress annoying "... is up to date." message"), if_changed and friends nicely suppress "is up to date" messages. We do not need per-Makefile tricks. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-15kbuild: add CONFIG_HEADERS_INSTALL and loosen the dependency of samplesMasahiro Yamada
Commit 5318321d367c ("samples: disable CONFIG_SAMPLES for UML") used a big hammer to fix the build errors under the samples/ directory. Only some samples actually include uapi headers from usr/include. Introduce CONFIG_HEADERS_INSTALL since 'depends on HEADERS_INSTALL' is clearer than 'depends on !UML'. If this option is enabled, uapi headers are installed before starting directory descending. I added 'depends on HEADERS_INSTALL' to per-sample CONFIG options. This allows UML to compile some samples. $ make ARCH=um allmodconfig samples/ [ snip ] CC [M] samples/configfs/configfs_sample.o CC [M] samples/kfifo/bytestream-example.o CC [M] samples/kfifo/dma-example.o CC [M] samples/kfifo/inttype-example.o CC [M] samples/kfifo/record-example.o CC [M] samples/kobject/kobject-example.o CC [M] samples/kobject/kset-example.o CC [M] samples/trace_events/trace-events-sample.o CC [M] samples/trace_printk/trace-printk.o AR samples/vfio-mdev/built-in.a AR samples/built-in.a Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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