1. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      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: default avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  2. 04 Aug, 2016 1 commit
    • Jason Baron's avatar
      dynamic_debug: add jump label support · 9049fc74
      Jason Baron authored
      Although dynamic debug is often only used for debug builds, sometimes
      its enabled for production builds as well.  Minimize its impact by using
      jump labels.  This reduces the text section by 7000+ bytes in the kernel
      image below.  It does increase data, but this should only be referenced
      when changing the direction of the branches, and hence usually not in
      cache.
      
           text     data     bss       dec     hex  filename
        8194852  4879776  925696  14000324  d5a0c4  vmlinux.pre
        8187337  4960224  925696  14073257  d6bda9  vmlinux.post
      
      Link: http://lkml.kernel.org/r/d165b465e8c89bc582d973758d40be44c33f018b.1467837322.git.jbaron@akamai.comSigned-off-by: default avatarJason Baron <jbaron@akamai.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Joe Perches <joe@perches.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9049fc74
  3. 03 Oct, 2014 1 commit
  4. 17 Jan, 2013 1 commit
  5. 24 Oct, 2012 1 commit
  6. 01 May, 2012 1 commit
  7. 30 Apr, 2012 2 commits
    • Jim Cromie's avatar
      dynamic_debug: make dynamic-debug work for module initialization · b48420c1
      Jim Cromie authored
      This introduces a fake module param $module.dyndbg.  Its based upon
      Thomas Renninger's $module.ddebug boot-time debugging patch from
      https://lkml.org/lkml/2010/9/15/397
      
      The 'fake' module parameter is provided for all modules, whether or
      not they need it.  It is not explicitly added to each module, but is
      implemented in callbacks invoked from parse_args.
      
      For builtin modules, dynamic_debug_init() now directly calls
      parse_args(..., &ddebug_dyndbg_boot_params_cb), to process the params
      undeclared in the modules, just after the ddebug tables are processed.
      
      While its slightly weird to reprocess the boot params, parse_args() is
      already called repeatedly by do_initcall_levels().  More importantly,
      the dyndbg queries (given in ddebug_query or dyndbg params) cannot be
      activated until after the ddebug tables are ready, and reusing
      parse_args is cleaner than doing an ad-hoc parse.  This reparse would
      break options like inc_verbosity, but they probably should be params,
      like verbosity=3.
      
      ddebug_dyndbg_boot_params_cb() handles both bare dyndbg (aka:
      ddebug_query) and module-prefixed dyndbg params, and ignores all other
      parameters.  For example, the following will enable pr_debug()s in 4
      builtin modules, in the order given:
      
        dyndbg="module params +p; module aio +p" module.dyndbg=+p pci.dyndbg
      
      For loadable modules, parse_args() in load_module() calls
      ddebug_dyndbg_module_params_cb().  This handles bare dyndbg params as
      passed from modprobe, and errors on other unknown params.
      
      Note that modprobe reads /proc/cmdline, so "modprobe foo" grabs all
      foo.params, strips the "foo.", and passes these to the kernel.
      ddebug_dyndbg_module_params_cb() is again called for the unknown
      params; it handles dyndbg, and errors on others.  The "doing" arg
      added previously contains the module name.
      
      For non CONFIG_DYNAMIC_DEBUG builds, the stub function accepts
      and ignores $module.dyndbg params, other unknowns get -ENOENT.
      
      If no param value is given (as in pci.dyndbg example above), "+p" is
      assumed, which enables all pr_debug callsites in the module.
      
      The dyndbg fake parameter is not shown in /sys/module/*/parameters,
      thus it does not use any resources.  Changes to it are made via the
      control file.
      
      Also change pr_info in ddebug_exec_queries to vpr_info,
      no need to see it all the time.
      Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
      CC: Thomas Renninger <trenn@suse.de>
      CC: Rusty Russell <rusty@rustcorp.com.au>
      Acked-by: default avatarJason Baron <jbaron@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b48420c1
    • Jim Cromie's avatar
      dynamic_debug: fix leading spaces in dynamic_debug.h · 3faa2860
      Jim Cromie authored
      clean up some space-before-tabs problems.
      Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
      Acked-by: default avatarJason Baron <jbaron@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3faa2860
  8. 24 Jan, 2012 4 commits
  9. 01 Nov, 2011 1 commit
  10. 18 Oct, 2011 1 commit
  11. 23 Aug, 2011 3 commits
  12. 04 Apr, 2011 1 commit
    • Jason Baron's avatar
      jump label: Introduce static_branch() interface · d430d3d7
      Jason Baron authored
      Introduce:
      
      static __always_inline bool static_branch(struct jump_label_key *key);
      
      instead of the old JUMP_LABEL(key, label) macro.
      
      In this way, jump labels become really easy to use:
      
      Define:
      
              struct jump_label_key jump_key;
      
      Can be used as:
      
              if (static_branch(&jump_key))
                      do unlikely code
      
      enable/disale via:
      
              jump_label_inc(&jump_key);
              jump_label_dec(&jump_key);
      
      that's it!
      
      For the jump labels disabled case, the static_branch() becomes an
      atomic_read(), and jump_label_inc()/dec() are simply atomic_inc(),
      atomic_dec() operations. We show testing results for this change below.
      
      Thanks to H. Peter Anvin for suggesting the 'static_branch()' construct.
      
      Since we now require a 'struct jump_label_key *key', we can store a pointer into
      the jump table addresses. In this way, we can enable/disable jump labels, in
      basically constant time. This change allows us to completely remove the previous
      hashtable scheme. Thanks to Peter Zijlstra for this re-write.
      
      Testing:
      
      I ran a series of 'tbench 20' runs 5 times (with reboots) for 3
      configurations, where tracepoints were disabled.
      
      jump label configured in
      avg: 815.6
      
      jump label *not* configured in (using atomic reads)
      avg: 800.1
      
      jump label *not* configured in (regular reads)
      avg: 803.4
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <20110316212947.GA8792@redhat.com>
      Signed-off-by: default avatarJason Baron <jbaron@redhat.com>
      Suggested-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
      Tested-by: default avatarDavid Daney <ddaney@caviumnetworks.com>
      Acked-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
      Acked-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      d430d3d7
  13. 03 Feb, 2011 1 commit
  14. 08 Jan, 2011 1 commit
  15. 15 Oct, 2010 1 commit
  16. 22 Sep, 2010 1 commit
  17. 05 Jul, 2010 1 commit
  18. 25 May, 2010 1 commit
  19. 15 Dec, 2009 1 commit
  20. 16 Apr, 2009 1 commit
  21. 24 Mar, 2009 2 commits