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2023-08-18gcov: shut up missing prototype warnings for internal stubsArnd Bergmann
gcov uses global functions that are called from generated code, but these have no prototype in a header, which causes a W=1 build warning: kernel/gcov/gcc_base.c:12:6: error: no previous prototype for '__gcov_init' [-Werror=missing-prototypes] kernel/gcov/gcc_base.c:40:6: error: no previous prototype for '__gcov_flush' [-Werror=missing-prototypes] kernel/gcov/gcc_base.c:46:6: error: no previous prototype for '__gcov_merge_add' [-Werror=missing-prototypes] kernel/gcov/gcc_base.c:52:6: error: no previous prototype for '__gcov_merge_single' [-Werror=missing-prototypes] Just turn off these warnings unconditionally for the two files that contain them. Link: https://lore.kernel.org/all/0820010f-e9dc-779d-7924-49c7df446bce@linux.ibm.com/ Link: https://lkml.kernel.org/r/20230725123042.2269077-1-arnd@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Peter Oberparleiter <oberpar@linux.ibm.com> Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2020-04-16gcov: Remove old GCC 3.4 supportWill Deacon
The kernel requires at least GCC 4.8 in order to build, and so there is no need to cater for the pre-4.7 gcov format. Remove the obsolete code. Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-05-14gcov: clang supportGreg Hackmann
LLVM uses profiling data that's deliberately similar to GCC, but has a very different way of exporting that data. LLVM calls llvm_gcov_init() once per module, and provides a couple of callbacks that we can use to ask for more data. We care about the "writeout" callback, which in turn calls back into compiler-rt/this module to dump all the gathered coverage data to disk: llvm_gcda_start_file() llvm_gcda_emit_function() llvm_gcda_emit_arcs() llvm_gcda_emit_function() llvm_gcda_emit_arcs() [... repeats for each function ...] llvm_gcda_summary_info() llvm_gcda_end_file() This design is much more stateless and unstructured than gcc's, and is intended to run at process exit. This forces us to keep some local state about which module we're dealing with at the moment. On the other hand, it also means we don't depend as much on how LLVM represents profiling data internally. See LLVM's lib/Transforms/Instrumentation/GCOVProfiling.cpp for more details on how this works, particularly GCOVProfiler::emitProfileArcs(), GCOVProfiler::insertCounterWriteout(), and GCOVProfiler::insertFlush(). [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20190417225328.208129-1-trong@android.com Signed-off-by: Greg Hackmann <ghackmann@android.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Tri Vo <trong@android.com> Co-developed-by: Nick Desaulniers <ndesaulniers@google.com> Co-developed-by: Tri Vo <trong@android.com> Tested-by: Trilok Soni <tsoni@quicinc.com> Tested-by: Prasad Sodagudi <psodagud@quicinc.com> Tested-by: Tri Vo <trong@android.com> Tested-by: Daniel Mentz <danielmentz@google.com> Tested-by: Petri Gynther <pgynther@google.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14gcov: clang: move common GCC code into gcc_base.cGreg Hackmann
Patch series "gcov: add Clang support", v4. This patch (of 3): base.c contains a few callbacks specific to GCC's gcov implementation. Move these into their own module in preparation for Clang support. Link: http://lkml.kernel.org/r/20190318025411.98014-2-trong@android.com Signed-off-by: Greg Hackmann <ghackmann@android.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Tri Vo <trong@android.com> Tested-by: Trilok Soni <tsoni@quicinc.com> Tested-by: Prasad Sodagudi <psodagud@quicinc.com> Tested-by: Tri Vo <trong@android.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: Daniel Mentz <danielmentz@google.com> Cc: Petri Gynther <pgynther@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-08gcov: remove CONFIG_GCOV_FORMAT_AUTODETECTMasahiro Yamada
CONFIG_GCOV_FORMAT_AUTODETECT compiles either gcc_3_4.c or gcc_4_7.c according to your GCC version. We can achieve the equivalent behavior by setting reasonable dependency with the knowledge of the compiler version. If GCC older than 4.7 is used, GCOV_FORMAT_3_4 is the default, but users are still allowed to select GCOV_FORMAT_4_7 in case the newer format is back-ported. On the other hand, If GCC 4.7 or newer is used, there is no reason to use GCOV_FORMAT_3_4, so it should be hidden. If you downgrade the compiler to GCC 4.7 or older, oldconfig/syncconfig will display a prompt for the choice because GCOV_FORMAT_3_4 becomes visible as a new symbol. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
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 <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09kbuild,gcov: simplify kernel/gcov/Makefile moreMasahiro Yamada
CONFIG_GCOV_FORMAT_3_4 / _4_7 / _AUTODETECT are exclusive. Compare the CC version only when _AUTODETECT is enabled. This change should have no impact. Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-01-09kbuild,gcov: simplify kernel/gcov/MakefileMasahiro Yamada
Kbuild descends into kernel/gcov/ directory only when CONFIG_GCOV_KERNEL is enabled. (See kernel/Makefile) CONFIG_GCOV_KERNEL check can be omitted in kernel/gcov/Makefile. Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-01-09kbuild,gcov: remove unnecessary workaroundMasahiro Yamada
Since commit 371fdc77af44 (kbuild: collect shorthands into scripts/Kbuild.include), scripts/Makefile.clean includes scripts/Kbuild.include. The workaround and the comment block in kernel/gcov/Makefile are no longer necessary. Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-01-09kbuild: do not add $(call ...) to invoke cc-version or cc-fullversionMasahiro Yamada
The macros cc-version, cc-fullversion and ld-version take no argument. It is not necessary to add $(call ...) to invoke them. Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Acked-by: Helge Deller <deller@gmx.de> [parisc] Signed-off-by: Michal Marek <mmarek@suse.cz>
2013-11-13gcov: compile specific gcov implementation based on gcc versionFrantisek Hrbata
Compile the correct gcov implementation file for the specific gcc version. Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com> Cc: Jan Stancek <jstancek@redhat.com> Cc: Kees Cook <keescook@chromium.org> Acked-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Andy Gospodarek <agospoda@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-17kernel: change to new flag variablematt mooney
Replace EXTRA_CFLAGS with ccflags-y. Signed-off-by: matt mooney <mfm@muteddisk.com> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2009-06-18gcov: add gcov profiling infrastructurePeter Oberparleiter
Enable the use of GCC's coverage testing tool gcov [1] with the Linux kernel. gcov may be useful for: * debugging (has this code been reached at all?) * test improvement (how do I change my test to cover these lines?) * minimizing kernel configurations (do I need this option if the associated code is never run?) The profiling patch incorporates the following changes: * change kbuild to include profiling flags * provide functions needed by profiling code * present profiling data as files in debugfs Note that on some architectures, enabling gcc's profiling option "-fprofile-arcs" for the entire kernel may trigger compile/link/ run-time problems, some of which are caused by toolchain bugs and others which require adjustment of architecture code. For this reason profiling the entire kernel is initially restricted to those architectures for which it is known to work without changes. This restriction can be lifted once an architecture has been tested and found compatible with gcc's profiling. Profiling of single files or directories is still available on all platforms (see config help text). [1] http://gcc.gnu.org/onlinedocs/gcc/Gcov.html Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Li Wei <W.Li@Sun.COM> Cc: Michael Ellerman <michaele@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com> Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: WANG Cong <xiyou.wangcong@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>