1. 21 May, 2018 2 commits
  2. 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
  3. 05 May, 2017 2 commits
  4. 27 Apr, 2017 2 commits
  5. 28 Feb, 2017 4 commits
  6. 27 Sep, 2016 1 commit
  7. 31 Jul, 2016 1 commit
  8. 29 Jul, 2016 1 commit
  9. 11 Jun, 2016 1 commit
    • Linus Torvalds's avatar
      vfs: make the string hashes salt the hash · 8387ff25
      Linus Torvalds authored
      We always mixed in the parent pointer into the dentry name hash, but we
      did it late at lookup time.  It turns out that we can simplify that
      lookup-time action by salting the hash with the parent pointer early
      instead of late.
      
      A few other users of our string hashes also wanted to mix in their own
      pointers into the hash, and those are updated to use the same mechanism.
      
      Hash users that don't have any particular initial salt can just use the
      NULL pointer as a no-salt.
      
      Cc: Vegard Nossum <vegard.nossum@oracle.com>
      Cc: George Spelvin <linux@sciencehorizons.net>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8387ff25
  10. 09 Dec, 2015 1 commit
    • Al Viro's avatar
      don't put symlink bodies in pagecache into highmem · 21fc61c7
      Al Viro authored
      kmap() in page_follow_link_light() needed to go - allowing to hold
      an arbitrary number of kmaps for long is a great way to deadlocking
      the system.
      
      new helper (inode_nohighmem(inode)) needs to be used for pagecache
      symlinks inodes; done for all in-tree cases.  page_follow_link_light()
      instrumented to yell about anything missed.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      21fc61c7
  11. 17 Apr, 2015 2 commits
  12. 15 Apr, 2015 1 commit
  13. 17 Feb, 2015 3 commits
  14. 19 Nov, 2014 1 commit
  15. 06 Jun, 2014 1 commit
  16. 07 Apr, 2014 1 commit
  17. 29 Jun, 2013 1 commit
  18. 14 Jul, 2012 2 commits
  19. 04 Jan, 2012 2 commits
  20. 02 Nov, 2011 1 commit
  21. 28 May, 2011 1 commit
  22. 26 May, 2011 2 commits
  23. 13 Jan, 2011 1 commit
  24. 07 Jan, 2011 3 commits
    • Nick Piggin's avatar
      fs: dcache reduce branches in lookup path · fb045adb
      Nick Piggin authored
      Reduce some branches and memory accesses in dcache lookup by adding dentry
      flags to indicate common d_ops are set, rather than having to check them.
      This saves a pointer memory access (dentry->d_op) in common path lookup
      situations, and saves another pointer load and branch in cases where we
      have d_op but not the particular operation.
      
      Patched with:
      
      git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
      Signed-off-by: default avatarNick Piggin <npiggin@kernel.dk>
      fb045adb
    • Nick Piggin's avatar
      fs: change d_hash for rcu-walk · b1e6a015
      Nick Piggin authored
      Change d_hash so it may be called from lock-free RCU lookups. See similar
      patch for d_compare for details.
      
      For in-tree filesystems, this is just a mechanical change.
      Signed-off-by: default avatarNick Piggin <npiggin@kernel.dk>
      b1e6a015
    • Nick Piggin's avatar
      fs: change d_compare for rcu-walk · 621e155a
      Nick Piggin authored
      Change d_compare so it may be called from lock-free RCU lookups. This
      does put significant restrictions on what may be done from the callback,
      however there don't seem to have been any problems with in-tree fses.
      If some strange use case pops up that _really_ cannot cope with the
      rcu-walk rules, we can just add new rcu-unaware callbacks, which would
      cause name lookup to drop out of rcu-walk mode.
      
      For in-tree filesystems, this is just a mechanical change.
      Signed-off-by: default avatarNick Piggin <npiggin@kernel.dk>
      621e155a
  25. 27 May, 2010 1 commit
  26. 27 Jan, 2010 1 commit