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* kbuild: compile-test kernel headers to ensure they are self-containedMasahiro Yamada2019-07-093-0/+1282
| | | | | | | | | | | | | | | | | | | | | 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>
* kheaders: include only headers into kheaders_data.tar.xzMasahiro Yamada2019-07-091-31/+16
| | | | | | | | | | | | | | | | | | | | | | | | Currently, kheaders_data.tar.xz contains some build scripts as well as headers. None of them is needed in the header archive. For ARCH=x86, this commit excludes the following from the archive: arch/x86/include/asm/Kbuild arch/x86/include/uapi/asm/Kbuild include/asm-generic/Kbuild include/config/auto.conf include/config/kernel.release include/config/tristate.conf include/uapi/asm-generic/Kbuild include/uapi/Kbuild kernel/gen_kheaders.sh This change is actually motivated for the planned header compile-testing because it will generate more build artifacts, which should not be included in the archive. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
* kheaders: remove meaningless -R option of 'ls'Masahiro Yamada2019-07-091-4/+4
| | | | | | | | | | | | | | | The -R option of 'ls' is supposed to be used for directories. -R, --recursive list subdirectories recursively Since 'find ... -type f' only matches to regular files, we do not expect directories passed to the 'ls' command here. Giving -R is harmless at least, but unneeded. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
* kbuild: support header-test-pattern-yMasahiro Yamada2019-07-092-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In my view, most of headers can be self-contained. So, it would be tedious to add every header to header-test-y explicitly. We usually end up with "all headers with some exceptions". There are two types in exceptions: [1] headers that are never compiled as standalone units For examples, include/linux/compiler-gcc.h is not intended for direct inclusion. We should always exclude such ones. [2] headers that are conditionally compiled as standalone units Some headers can be compiled only for particular architectures. For example, include/linux/arm-cci.h can be compiled only for arm/arm64 because it requires <asm/arm-cci.h> to exist. Clang can compile include/soc/nps/mtm.h only for arc because it contains an arch-specific register in inline assembler. So, you can write Makefile like this: header-test- += linux/compiler-gcc.h header-test-$(CONFIG_ARM) += linux/arm-cci.h header-test-$(CONFIG_ARM64) += linux/arm-cci.h header-test-$(CONFIG_ARC) += soc/nps/mtm.h The new syntax header-test-pattern-y will be useful to specify "the rest". The typical usage is like this: header-test-pattern-y += */*.h This will add all the headers in sub-directories to the test coverage, excluding $(header-test-). In this regards, header-test-pattern-y behaves like a weaker variant of header-test-y. Caveat: The patterns in header-test-pattern-y are prefixed with $(srctree)/$(src)/ but not $(objtree)/$(obj)/. Stale generated headers are often left over when you traverse the git history without cleaning. Wildcard patterns for $(objtree) may match to stale headers, which could fail to compile. One pitfall is $(srctree)/$(src)/ and $(objtree)/$(obj)/ point to the same directory for in-tree building. So, header-test-pattern-y should be used with care since it can potentially match to stale headers. Caveat2: You could use wildcard for header-test-. For example, header-test- += asm-generic/% ... will exclude headers in asm-generic directory. Unfortunately, the wildcard character is '%' instead of '*' here because this is evaluated by $(filter-out ...) whereas header-test-pattern-y is evaluated by $(wildcard ...). This is a kludge, but seems useful in some places... Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Jani Nikula <jani.nikula@intel.com>
* kbuild: do not create wrappers for header-test-yMasahiro Yamada2019-07-097-12/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* kbuild: compile-test exported headers to ensure they are self-containedMasahiro Yamada2019-07-086-2/+148
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* init/Kconfig: add CONFIG_CC_CAN_LINKMasahiro Yamada2019-07-072-1/+4
| | | | | | | Currently, scripts/cc-can-link.sh is run just for BPFILTER_UMH, but defining CC_CAN_LINK will be useful in other places. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kallsyms: exclude kasan local symbols on s390Vasily Gorbik2019-07-071-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gcc asan instrumentation emits the following sequence to store frame pc when the kernel is built with CONFIG_RELOCATABLE: debug/vsprintf.s: .section .data.rel.ro.local,"aw" .align 8 .LC3: .quad .LASANPC4826@GOTOFF .text .align 8 .type number, @function number: .LASANPC4826: and in case reloc is issued for LASANPC label it also gets into .symtab with the same address as actual function symbol: $ nm -n vmlinux | grep 0000000001397150 0000000001397150 t .LASANPC4826 0000000001397150 t number In the end kernel backtraces are almost unreadable: [ 143.748476] Call Trace: [ 143.748484] ([<000000002da3e62c>] .LASANPC2671+0x114/0x190) [ 143.748492] [<000000002eca1a58>] .LASANPC2612+0x110/0x160 [ 143.748502] [<000000002de9d830>] print_address_description+0x80/0x3b0 [ 143.748511] [<000000002de9dd64>] __kasan_report+0x15c/0x1c8 [ 143.748521] [<000000002ecb56d4>] strrchr+0x34/0x60 [ 143.748534] [<000003ff800a9a40>] kasan_strings+0xb0/0x148 [test_kasan] [ 143.748547] [<000003ff800a9bba>] kmalloc_tests_init+0xe2/0x528 [test_kasan] [ 143.748555] [<000000002da2117c>] .LASANPC4069+0x354/0x748 [ 143.748563] [<000000002dbfbb16>] do_init_module+0x136/0x3b0 [ 143.748571] [<000000002dbff3f4>] .LASANPC3191+0x2164/0x25d0 [ 143.748580] [<000000002dbffc4c>] .LASANPC3196+0x184/0x1b8 [ 143.748587] [<000000002ecdf2ec>] system_call+0xd8/0x2d8 Since LASANPC labels are not even unique and get into .symtab only due to relocs filter them out in kallsyms. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: add more hints about SUBDIRS replacementMasahiro Yamada2019-07-071-0/+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>
* coccinelle: api/stream_open: treat all wait_.*() calls as blockingKirill Smelkov2019-07-071-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously steam_open.cocci was treating only wait_event_.* - e.g. wait_event_interruptible - as a blocking operation. However e.g. wait_for_completion_interruptible is also blocking, and so from this point of view it would be more logical to treat all wait_.* as a blocking point. The logic of this change actually came up for real when drivers/pci/switch/switchtec.c changed from using wait_event_interruptible to wait_for_completion_interruptible: https://lore.kernel.org/linux-pci/20190413170056.GA11293@deco.navytux.spb.ru/ https://lore.kernel.org/linux-pci/20190415145456.GA15280@deco.navytux.spb.ru/ https://lore.kernel.org/linux-pci/20190415154102.GB17661@deco.navytux.spb.ru/ For a driver that uses nonseekable_open with read/write having stream semantic and read also calling e.g. wait_for_completion_interruptible, running stream_open.cocci before this patch would produce: WARNING: <driver>_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. while after this patch it will report: ERROR: <driver>_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. Signed-off-by: Kirill Smelkov <kirr@nexedi.com> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* coccinelle: put_device: Add a cast to an expression for an assignmentMarkus Elfring2019-07-071-1/+1
| | | | | | | | | | | | | Extend a when constraint in a SmPL rule so that an additional cast is optionally excluded from source code searches for an expression in assignments. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Suggested-by: Julia Lawall <Julia.Lawall@lip6.fr> Link: https://lore.kernel.org/lkml/alpine.DEB.2.21.1902160934400.3212@hadrien/ Link: https://systeme.lip6.fr/pipermail/cocci/2019-February/005592.html Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* coccinelle: put_device: Adjust a message constructionMarkus Elfring2019-07-071-5/+4
| | | | | | | | | | | The Linux coding style tolerates long string literals so that the provided information can be easier found also by search tools like grep. Thus simplify a message construction in a SmPL rule by concatenating text with two plus operators less. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* coccinelle: kstrdup: Fix typo in warning messagesRikard Falkeborn2019-07-071-4/+4
| | | | | | | | Replace 'kstrdep' with 'kstrdup' in warning messages. Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com> Acked-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: Add ability to test Clang's integrated assemblerNathan Chancellor2019-07-041-0/+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>
* fixdep: check return value of printf() and putchar()Masahiro Yamada2019-07-011-10/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When there is not enough space on your storage device, the build will fail with 'No space left on device' error message. The reason is obvious from the message, so you will free up some disk space, then you will resume the build. However, sometimes you may still see a mysterious error message: unterminated call to function 'wildcard': missing ')'. If you run out of the disk space, fixdep may end up with generating incomplete .*.cmd files. For example, if the disk-full error occurs while fixdep is running print_dep(), the .*.cmd might be truncated like this: $(wildcard include/config/ When you run 'make' next time, this broken .*.cmd will be included, then Make will terminate parsing since it is a wrong syntax. Once this happens, you need to run 'make clean' or delete the broken .*.cmd file manually. Even if you do not see any error message, the .*.cmd files after any error could be potentially incomplete, and unreliable. You may miss the re-compilation due to missing header dependency. If printf() cannot output the string for disk shortage or whatever reason, it returns a negative value, but currently fixdep does not check it at all. Consequently, fixdep *successfully* generates a broken .*.cmd file. Make never notices that since fixdep exits with 0, which means success. Given the intended usage of fixdep, it must respect the return value of not only malloc(), but also printf() and putchar(). This seems a long-standing issue since the introduction of fixdep. In old days, Kbuild tried to provide an extra safety by letting fixdep output to a temporary file and renaming it after everything is done: scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\ rm -f $(depfile); \ mv -f $(dot-target).tmp $(dot-target).cmd) It was no help to avoid the current issue; fixdep successfully created a truncated tmp file, which would be renamed to a .*.cmd file. This problem should be fixed by propagating the error status to the build system because: [1] Since commit 9c2af1c7377a ("kbuild: add .DELETE_ON_ERROR special target"), Make will delete the target automatically on any failure in the recipe. [2] Since commit 392885ee82d3 ("kbuild: let fixdep directly write to .*.cmd files"), .*.cmd file is included only when the corresponding target already exists. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: split modules.order build rule out of 'modules' targetMasahiro Yamada2019-07-011-2/+4
| | | | | | | modules.order is a real target. Split its build rule out like modules.builtin Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: fix missed rebuild of modules.builtinMasahiro Yamada2019-07-011-4/+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>
* kbuild: save $(strip ...) for calling if_changed and friendsMasahiro Yamada2019-07-011-3/+3
| | | | | | | | | | | | | | | | | | | | The string returned by $(filter-out ...) does not contain any leading or trailing spaces. With the previous commit, 'any-prereq' no longer contains any excessive spaces. Nor does 'cmd-check' since it expands to a $(filter-out ...) call. So, only the space that matters is the one between 'any-prereq' and 'cmd-check'. By removing it from the code, we can save $(strip ...) evaluation. This refactoring is possible because $(any-prereq)$(cmd-check) is only passed to the first argument of $(if ...), so we are only interested in whether or not it is empty. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: save $(strip ...) for calling any-prepreqMasahiro Yamada2019-07-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | The string returned by $(filter-out ...) does not contain any leading or trailing spaces. So, only the space that matters is the one between $(filter-out $(PHONY),$?) and $(filter-out $(PHONY) $(wildcard $^),$^) By removing it from the code, we can save $(strip ...) evaluation. This refactoring is possible because $(any-prereq) is only passed to the first argument of $(if ...), so we are only interested in whether or not it is empty. This is also the prerequisite for the next commit. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: rename arg-check to cmd-checkMasahiro Yamada2019-07-011-7/+7
| | | | | | | | I prefer 'cmd-check' for consistency. We have 'echo-cmd', 'cmd', 'cmd_and_fixdep', etc. in this file. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: fix 'No such file or directory' warning for headers_installMasahiro Yamada2019-06-231-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit d5470d14431e ("kbuild: re-implement Makefile.headersinst without recursion"), headers_install emits an ugly warning. $ make headers_install [ snip ] UPD include/generated/uapi/linux/version.h find: ‘./include/uapi/Kbuild’: No such file or directory HDRINST usr/include/video/uvesafb.h ... This happens for GNU Make <= 4.2.1 When I wrote that commit, I missed this warning because I was using the state-of-the-art Make version compiled from the git tree. $(wildcard $(src)/*/) is intended to match to only existing directories since it has a trailing slash, but actually matches to regular files too. (include/uapi/Kbuild in this case) This is a bug of GNU Make, and was fixed by: | commit b7acb10e86dc8f5fdf2a2bbd87e1059c315e31d6 | Author: spagoveanu@gmail.com <spagoveanu@gmail.com> | Date: Wed Jun 20 02:03:48 2018 +0300 | | * src/dir.c: Preserve glob d_type field We need to cater to old Make versions. Add '$(filter %/,...) to filter out the regular files. Fixes: d5470d14431e ("kbuild: re-implement Makefile.headersinst without recursion") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* genksyms: Teach parser about 128-bit built-in typesWill Deacon2019-06-232-0/+6
| | | | | | | | | | | | | | | | | | | __uint128_t crops up in a few files that export symbols to modules, so teach genksyms about it and the other GCC built-in 128-bit integer types so that we don't end up skipping the CRC generation for some symbols due to the parser failing to spot them: | WARNING: EXPORT symbol "kernel_neon_begin" [vmlinux] version | generation failed, symbol will not be versioned. | ld: arch/arm64/kernel/fpsimd.o: relocation R_AARCH64_ABS32 against | `__crc_kernel_neon_begin' can not be used when making a shared | object | ld: arch/arm64/kernel/fpsimd.o:(.data+0x0): dangerous relocation: | unsupported relocation Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: Remove unnecessary -Wno-unused-valueNathan Huckleberry2019-06-231-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This flag turns off several other warnings that would be useful. Most notably -warn_unused_result is disabled. All of the following warnings are currently disabled: UnusedValue |-UnusedComparison |-warn_unused_comparison |-UnusedResult |-warn_unused_result |-UnevaluatedExpression |-PotentiallyEvaluatedExpression |-warn_side_effects_typeid |-warn_side_effects_unevaluated_context |-warn_unused_expr |-warn_unused_voidptr |-warn_unused_container_subscript_expr |-warn_unused_call With this flag removed there are ~10 warnings. Patches have been submitted for each of these warnings. Reported-by: Nick Desaulniers <ndesaulniers@google.com> Cc: clang-built-linux@googlegroups.com Link: https://github.com/ClangBuiltLinux/linux/issues/520 Signed-off-by: Nathan Huckleberry <nhuck@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* lib/raid6: refactor unroll rules with pattern rulesMasahiro Yamada2019-06-231-86/+11
| | | | | | | | | | This Makefile repeats very similar rules. Let's use pattern rules. $(UNROLL) can be replaced with $*. No intended change in behavior. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* lib/raid6: remove duplicated CFLAGS_REMOVE_altivec8.oMasahiro Yamada2019-06-231-1/+0
| | | | | | No intended change in behavior. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: Enable -WuninitializedNathan Chancellor2019-06-231-1/+0
| | | | | | | | | | | | | | | | | | This helps fine very dodgy behavior through both -Wuninitialized (warning that a variable is always uninitialized) and -Wsometimes-uninitialized (warning that a variable is sometimes uninitialized, like GCC's -Wmaybe-uninitialized). These warnings catch things that GCC doesn't such as: https://lore.kernel.org/lkml/86649ee4-9794-77a3-502c-f4cd10019c36@lca.pw/ We very much want to catch these so turn this warning on so that CI is aware of it. Link: https://github.com/ClangBuiltLinux/linux/issues/381 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: Add -Werror=unknown-warning-option to CLANG_FLAGSNathan Chancellor2019-06-231-0/+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>
* kbuild: add support for ensuring headers are self-containedJani Nikula2019-06-159-12/+32
| | | | | | | | | | | | | | 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>
* kbuild: deb-pkg: do not run headers_checkMasahiro Yamada2019-06-151-1/+1
| | | | | | | | | | | | | It is absolutely fine to add extra sanity checks in package scripts, but it is not necessary to do so. This is already covered by the daily compile-testing (0day bot etc.) because headers_check is run as a part of the normal build process when CONFIG_HEADERS_CHECK=y. Replace it with the newly-added "make headers". Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: simplify scripts/headers_install.shMasahiro Yamada2019-06-152-29/+21
| | | | | | | Now that headers_install.sh is invoked per file, remove the for-loop in the shell script. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: move hdr-inst shorthand to top MakefileMasahiro Yamada2019-06-152-6/+2
| | | | | | | 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>
* kbuild: re-implement Makefile.headersinst without recursionMasahiro Yamada2019-06-153-84/+62
| | | | | | | | | | | | | | | | | 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>
* kbuild: add 'headers' target to build up uapi headers in usr/includeMasahiro Yamada2019-06-153-15/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* kbuild: build all prerequisites of headers_install simultaneouslyMasahiro Yamada2019-06-151-2/+5
| | | | | | | | | | | | 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>
* kbuild: remove build_unifdef target in scripts/MakefileMasahiro Yamada2019-06-152-6/+1
| | | | | | | | | 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>
* kbuild: add CONFIG_HEADERS_INSTALL and loosen the dependency of samplesMasahiro Yamada2019-06-1512-14/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* kbuild: fix Kconfig prompt of CONFIG_HEADERS_CHECKMasahiro Yamada2019-06-151-3/+3
| | | | | | | | | | | Prior to commit 257edce66d31 ("kbuild: exploit parallel building for CONFIG_HEADERS_CHECK"), the sanity check of exported headers was done as a side-effect of build rule of vmlinux. That commit is good, but I missed to update the prompt of the Kconfig entry. For the sake of preciseness, lets' say "when building 'all'". Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: make gdb_script depend on prepare0 instead of prepareMasahiro Yamada2019-06-151-1/+1
| | | | | | | | | 'gdb_script' needs headers generated by ./Kbuild, which is visited by 'prepare0'. None of 'gdb_script' depends on 'prepare'. Loosen the dependency. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: remove stale dependency between Documentation/ and headers_installMasahiro Yamada2019-06-151-2/+1
| | | | | | | | | | | Commit 8e2faea877eb ("Make Documenation depend on headers_install") dates back to 2014, which is before Sphinx was introduced for the kernel documentation. Since none of DOC_TARGET requires headers_install, it is strange to run it only for the single target "Documentation/". Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: remove headers_{install,check}_allMasahiro Yamada2019-06-154-54/+3
| | | | | | | | | | | | | | | | headers_install_all does not make much sense any more because different architectures export different set of uapi/linux/ headers. As you see in include/uapi/linux/Kbuild, the installation of a.out.h, kvm.h, and kvm_para.h is arch-dependent. So, headers_install_all repeats the installation/removal of them. If somebody really thinks it is useful to do headers_install for all architectures, it would be possible by small shell-scripting, but the top Makefile does not have to provide entry targets just for that purpose. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Sam Ravnborg <sam@ravnborg.org>
* kbuild: Remove -Waggregate-return from scripts/Makefile.extrawarnMathieu Malaterre2019-06-091-1/+0
| | | | | | | | | | | | | | | | | It makes little sense to pass -Waggregate-return these days since large part of the linux kernel rely on returning struct(s). For instance: ../include/linux/timekeeping.h: In function 'show_uptime': ../include/linux/ktime.h:91:34: error: function call has aggregate value [-Werror=aggregate-return] #define ktime_to_timespec64(kt) ns_to_timespec64((kt)) ^~~~~~~~~~~~~~~~~~~~~~ ../include/linux/timekeeping.h:166:8: note: in expansion of macro 'ktime_to_timespec64' *ts = ktime_to_timespec64(ktime_get_coarse_boottime()); Remove this warning from W=2 completely. Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* Linux 5.2-rc4v5.2-rc4Linus Torvalds2019-06-091-1/+1
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* Merge tag 'ceph-for-5.2-rc4' of git://github.com/ceph/ceph-clientLinus Torvalds2019-06-098-135/+156
|\ | | | | | | | | | | | | | | | | | | | | | | Pull ceph fixes from Ilya Dryomov: "A change to call iput() asynchronously to avoid a possible deadlock when iput_final() needs to wait for in-flight I/O (e.g. readahead) and a fixup for a cleanup that went into -rc1" * tag 'ceph-for-5.2-rc4' of git://github.com/ceph/ceph-client: ceph: fix error handling in ceph_get_caps() ceph: avoid iput_final() while holding mutex or in dispatch thread ceph: single workqueue for inode related works
| * ceph: fix error handling in ceph_get_caps()Yan, Zheng2019-06-051-11/+11
| | | | | | | | | | | | | | | | | | | | The function return 0 even when interrupted or try_get_cap_refs() return error. Fixes: 1199d7da2d ("ceph: simplify arguments and return semantics of try_get_cap_refs") Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
| * ceph: avoid iput_final() while holding mutex or in dispatch threadYan, Zheng2019-06-056-27/+71
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | iput_final() may wait for reahahead pages. The wait can cause deadlock. For example: Workqueue: ceph-msgr ceph_con_workfn [libceph] Call Trace: schedule+0x36/0x80 io_schedule+0x16/0x40 __lock_page+0x101/0x140 truncate_inode_pages_range+0x556/0x9f0 truncate_inode_pages_final+0x4d/0x60 evict+0x182/0x1a0 iput+0x1d2/0x220 iterate_session_caps+0x82/0x230 [ceph] dispatch+0x678/0xa80 [ceph] ceph_con_workfn+0x95b/0x1560 [libceph] process_one_work+0x14d/0x410 worker_thread+0x4b/0x460 kthread+0x105/0x140 ret_from_fork+0x22/0x40 Workqueue: ceph-msgr ceph_con_workfn [libceph] Call Trace: __schedule+0x3d6/0x8b0 schedule+0x36/0x80 schedule_preempt_disabled+0xe/0x10 mutex_lock+0x2f/0x40 ceph_check_caps+0x505/0xa80 [ceph] ceph_put_wrbuffer_cap_refs+0x1e5/0x2c0 [ceph] writepages_finish+0x2d3/0x410 [ceph] __complete_request+0x26/0x60 [libceph] handle_reply+0x6c8/0xa10 [libceph] dispatch+0x29a/0xbb0 [libceph] ceph_con_workfn+0x95b/0x1560 [libceph] process_one_work+0x14d/0x410 worker_thread+0x4b/0x460 kthread+0x105/0x140 ret_from_fork+0x22/0x40 In above example, truncate_inode_pages_range() waits for readahead pages while holding s_mutex. ceph_check_caps() waits for s_mutex and blocks OSD dispatch thread. Later OSD replies (for readahead) can't be handled. ceph_check_caps() also may lock snap_rwsem for read. So similar deadlock can happen if iput_final() is called while holding snap_rwsem. In general, it's not good to call iput_final() inside MDS/OSD dispatch threads or while holding any mutex. The fix is introducing ceph_async_iput(), which calls iput_final() in workqueue. Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
| * ceph: single workqueue for inode related worksYan, Zheng2019-06-054-97/+74
| | | | | | | | | | | | | | | | | | | | We have three workqueue for inode works. Later patch will introduce one more work for inode. It's not good to introcuce more workqueue and add more 'struct work_struct' to 'struct ceph_inode_info'. Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
* | Merge tag 'for-linus-5.2b-rc4-tag' of ↵Linus Torvalds2019-06-081-19/+19
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fix from Juergen Gross: "Just one fix for the Xen block frontend driver avoiding allocations with order > 0" * tag 'for-linus-5.2b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen-blkfront: switch kcalloc to kvcalloc for large array allocation
| * | xen-blkfront: switch kcalloc to kvcalloc for large array allocationRoger Pau Monne2019-06-041-19/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no reason to request physically contiguous memory for those allocations. [boris: added CC to stable] Cc: stable@vger.kernel.org Reported-by: Ian Jackson <ian.jackson@citrix.com> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | | Merge tag 's390-5.2-4' of ↵Linus Torvalds2019-06-082-2/+5
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Heiko Carstens: - fix stack unwinder: the stack unwinder rework has on off-by-one bug which prevents following stack backchains over more than one context (e.g. irq -> process). - fix address space detection in exception handler: if user space switches to access register mode, which is not supported anymore, the exception handler may resolve to the wrong address space. * tag 's390-5.2-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/unwind: correct stack switching during unwind s390/mm: fix address space detection in exception handling
| * | | s390/unwind: correct stack switching during unwindVasily Gorbik2019-06-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adjust conditions in on_stack function. That fixes backchain unwinder which was unable to read pt_regs at the very bottom of the stack and hence couldn't follow stacks (e.g. from async stack to a task stack). Fixes: 78c98f907413 ("s390/unwind: introduce stack unwind API") Reported-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-18 18:50:50 +0100