user/sven/linux.git/scripts/Makefile.extrawarn, branch v5.1.10

Merge tag 'kbuild-v4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2018-11-03T17:47:33Z

Pull Kbuild updates from Masahiro Yamada: - clean-up leftovers in Kconfig files - remove stale oldnoconfig and silentoldconfig targets - remove unneeded cc-fullversion and cc-name variables - improve merge_config script to allow overriding option prefix * tag 'kbuild-v4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: remove cc-name variable kbuild: replace cc-name test with CONFIG_CC_IS_CLANG merge_config.sh: Allow to define config prefix kbuild: remove unused cc-fullversion variable kconfig: remove silentoldconfig target kconfig: remove oldnoconfig target powerpc: PCI_MSI needs PCI powerpc: remove CONFIG_MCA leftovers powerpc: remove CONFIG_PCI_QSPAN scsi: aha152x: rename the PCMCIA define

kbuild: replace cc-name test with CONFIG_CC_IS_CLANG

2018-11-02T13:49:00Z

Evaluating cc-name invokes the compiler every time even when you are not compiling anything, like 'make help'. This is not efficient. The compiler type has been already detected in the Kconfig stage. Use CONFIG_CC_IS_CLANG, instead. Signed-off-by: Masahiro Yamada Acked-by: Michael Ellerman (powerpc) Acked-by: Paul Burton (MIPS) Acked-by: Joel Stanley

Merge tag 'compiler-attributes-for-linus-4.20-rc1' of https://github.com/ojeda/linux

2018-11-02T01:34:46Z

Pull compiler attribute updates from Miguel Ojeda: "This is an effort to disentangle the include/linux/compiler*.h headers and bring them up to date. The main idea behind the series is to use feature checking macros (i.e. __has_attribute) instead of compiler version checks (e.g. GCC_VERSION), which are compiler-agnostic (so they can be shared, reducing the size of compiler-specific headers) and version-agnostic. Other related improvements have been performed in the headers as well, which on top of the use of __has_attribute it has amounted to a significant simplification of these headers (e.g. GCC_VERSION is now only guarding a few non-attribute macros). This series should also help the efforts to support compiling the kernel with clang and icc. A fair amount of documentation and comments have also been added, clarified or removed; and the headers are now more readable, which should help kernel developers in general. The series was triggered due to the move to gcc >= 4.6. In turn, this series has also triggered Sparse to gain the ability to recognize __has_attribute on its own. Finally, the __nonstring variable attribute series has been also applied on top; plus two related patches from Nick Desaulniers for unreachable() that came a bit afterwards" * tag 'compiler-attributes-for-linus-4.20-rc1' of https://github.com/ojeda/linux: compiler-gcc: remove comment about gcc 4.5 from unreachable() compiler.h: update definition of unreachable() Compiler Attributes: ext4: remove local __nonstring definition Compiler Attributes: auxdisplay: panel: use __nonstring Compiler Attributes: enable -Wstringop-truncation on W=1 (gcc >= 8) Compiler Attributes: add support for __nonstring (gcc >= 8) Compiler Attributes: add MAINTAINERS entry Compiler Attributes: add Doc/process/programming-language.rst Compiler Attributes: remove uses of __attribute__ from compiler.h Compiler Attributes: KENTRY used twice the "used" attribute Compiler Attributes: use feature checks instead of version checks Compiler Attributes: add missing SPDX ID in compiler_types.h Compiler Attributes: remove unneeded sparse (__CHECKER__) tests Compiler Attributes: homogenize __must_be_array Compiler Attributes: remove unneeded tests Compiler Attributes: always use the extra-underscores syntax Compiler Attributes: remove unused attributes

Makefile: Globally enable VLA warning

2018-10-11T15:17:50Z

Now that Variable Length Arrays (VLAs) have been entirely removed[1] from the kernel, enable the VLA warning globally. The only exceptions to this are the KASan an UBSan tests which are explicitly checking that VLAs trigger their respective tests. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Cc: Masahiro Yamada Cc: Andrew Morton Cc: David Airlie Cc: linux-kbuild@vger.kernel.org Cc: intel-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: Kees Cook

Compiler Attributes: enable -Wstringop-truncation on W=1 (gcc >= 8)

2018-09-30T18:14:04Z

Commit 217c3e019675 ("disable stringop truncation warnings for now") disabled -Wstringop-truncation since it was too noisy. Having __nonstring available allows us to let GCC know that a string is not meant to be NUL-terminated, which helps suppressing some -Wstringop-truncation warnings. Note that using __nonstring actually triggers other warnings (-Wstringop-overflow, which is on by default) which may be real problems. Therefore, cleaning up -Wstringop-truncation warnings also buys us the ability to uncover further potential problems. To encourage the use of __nonstring, we put the warning back at W=1. In the future, if we end up with a fairly warning-free tree, we might want to enable it by default. Tested-by: Sedat Dilek # on top of v4.19-rc5, clang 7 Reviewed-by: Kees Cook Reviewed-by: Nick Desaulniers Reviewed-by: Luc Van Oostenryck Signed-off-by: Miguel Ojeda

Kbuild: suppress packed-not-aligned warning for default setting only

2018-01-18T00:37:53Z

gcc-8 reports many -Wpacked-not-aligned warnings. The below are some examples. ./include/linux/ceph/msgr.h:67:1: warning: alignment 1 of 'struct ceph_entity_addr' is less than 8 [-Wpacked-not-aligned] } __attribute__ ((packed)); ./include/linux/ceph/msgr.h:67:1: warning: alignment 1 of 'struct ceph_entity_addr' is less than 8 [-Wpacked-not-aligned] } __attribute__ ((packed)); ./include/linux/ceph/msgr.h:67:1: warning: alignment 1 of 'struct ceph_entity_addr' is less than 8 [-Wpacked-not-aligned] } __attribute__ ((packed)); This patch suppresses this kind of warnings for default setting. Signed-off-by: Xiongfeng Wang Signed-off-by: Masahiro Yamada

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

Kbuild: enable -Wunused-macros warning for "make W=2"

2017-08-31T23:53:17Z

We have lots of dead defines and macros in drivers, lets offer users a way to detect and eventually remove them. Signed-off-by: Johannes Thumshirn Signed-off-by: Masahiro Yamada

kbuild: drop -Wno-unknown-warning-option from clang options

2017-04-23T07:09:15Z

Since commit c3f0d0bc5b01 ("kbuild, LLVMLinux: Add -Werror to cc-option to support clang"), cc-option and friends work nicely for clang. However, -Wno-unknown-warning-option makes clang happy with any unknown warning options even if -Werror is specified. Once -Wno-unknown-warning-option is added, any succeeding call of cc-disable-warning is evaluated positive, then unknown warning options are accepted. This should be dropped. Signed-off-by: Masahiro Yamada

Kbuild: enable -Wmaybe-uninitialized warnings by default

2016-11-11T16:45:08Z

Previously the warnings were added back at the W=1 level and above, this now turns them on again by default, assuming that we have addressed all warnings and again have a clean build for v4.10. I found a number of new warnings in linux-next already and submitted bugfixes for those. Hopefully they are caught by the 0day builder in the future as soon as this patch is merged. Signed-off-by: Arnd Bergmann Signed-off-by: Linus Torvalds