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: 's avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: 's avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: 's avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: 's avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  2. 10 Jul, 2017 2 commits
  3. 24 Dec, 2016 1 commit
  4. 11 Oct, 2016 1 commit
  5. 17 Mar, 2016 2 commits
    • Kees Cook's avatar
      lib: add "on"/"off" support to kstrtobool · a81a5a17
      Kees Cook authored
      Add support for "on" and "off" when converting to boolean.
      Signed-off-by: 's avatarKees Cook <keescook@chromium.org>
      Cc: Amitkumar Karwar <akarwar@marvell.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Joe Perches <joe@perches.com>
      Cc: Kalle Valo <kvalo@codeaurora.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Nishant Sarmukadam <nishants@marvell.com>
      Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
      Cc: Steve French <sfrench@samba.org>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      a81a5a17
    • Kees Cook's avatar
      lib: move strtobool() to kstrtobool() · ef951599
      Kees Cook authored
      Create the kstrtobool_from_user() helper and move strtobool() logic into
      the new kstrtobool() (matching all the other kstrto* functions).
      Provides an inline wrapper for existing strtobool() callers.
      Signed-off-by: 's avatarKees Cook <keescook@chromium.org>
      Cc: Joe Perches <joe@perches.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: Amitkumar Karwar <akarwar@marvell.com>
      Cc: Nishant Sarmukadam <nishants@marvell.com>
      Cc: Kalle Valo <kvalo@codeaurora.org>
      Cc: Steve French <sfrench@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      ef951599
  6. 10 Sep, 2015 1 commit
  7. 24 Jan, 2014 1 commit
  8. 18 Dec, 2012 1 commit
  9. 07 Mar, 2012 1 commit
  10. 09 Feb, 2012 1 commit
    • David Howells's avatar
      Reduce the number of expensive division instructions done by _parse_integer() · 690d137f
      David Howells authored
      _parse_integer() does one or two division instructions (which are slow)
      per digit parsed to perform the overflow check.
      
      Furthermore, these are particularly expensive examples of division
      instruction as the number of clock cycles required to complete them may
      go up with the position of the most significant set bit in the dividend:
      
      	if (*res > div_u64(ULLONG_MAX - val, base))
      
      which is as maximal as possible.
      
      Worse, on 32-bit arches, more than one of these division instructions
      may be required per digit.
      
      So, assuming we don't support a base of more than 16, skip the check if the
      top nibble of the result is not set at this point.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      [ Changed it to not dereference the pointer all the time - even if the
        compiler can and does optimize it away, the code just looks cleaner.
        And edited the top nybble test slightly to make the code generated on
        x86-64 better in the loop - test against a hoisted constant instead of
        shifting and testing the result ]
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      690d137f
  11. 01 Nov, 2011 1 commit
  12. 26 Jul, 2011 1 commit
  13. 25 May, 2011 1 commit
    • Alexey Dobriyan's avatar
      lib: add kstrto*_from_user() · c196e32a
      Alexey Dobriyan authored
      There is quite a lot of code which does copy_from_user() + strict_strto*()
      or simple_strto*() combo in slightly different ways.
      
      Before doing conversions all over tree, let's get final API correct.
      
      Enter kstrtoull_from_user() and friends.
      
      Typical code which uses them looks very simple:
      
      	TYPE val;
      	int rv;
      
      	rv = kstrtoTYPE_from_user(buf, count, 0, &val);
      	if (rv < 0)
      		return rv;
      	[use val]
      	return count;
      
      There is a tiny semantic difference from the plain kstrto*() API -- the
      latter allows any amount of leading zeroes, while the former copies data
      into buffer on stack and thus allows leading zeroes as long as it fits
      into buffer.
      
      This shouldn't be a problem for typical usecase "echo 42 > /proc/x".
      
      The point is to make reading one integer from userspace _very_ simple and
      very bug free.
      Signed-off-by: 's avatarAlexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      c196e32a
  14. 14 Apr, 2011 1 commit
  15. 23 Mar, 2011 1 commit
    • Alexey Dobriyan's avatar
      kstrto*: converting strings to integers done (hopefully) right · 33ee3b2e
      Alexey Dobriyan authored
      1. simple_strto*() do not contain overflow checks and crufty,
         libc way to indicate failure.
      2. strict_strto*() also do not have overflow checks but the name and
         comments pretend they do.
      3. Both families have only "long long" and "long" variants,
         but users want strtou8()
      4. Both "simple" and "strict" prefixes are wrong:
         Simple doesn't exactly say what's so simple, strict should not exist
         because conversion should be strict by default.
      
      The solution is to use "k" prefix and add convertors for more types.
      Enter
      	kstrtoull()
      	kstrtoll()
      	kstrtoul()
      	kstrtol()
      	kstrtouint()
      	kstrtoint()
      
      	kstrtou64()
      	kstrtos64()
      	kstrtou32()
      	kstrtos32()
      	kstrtou16()
      	kstrtos16()
      	kstrtou8()
      	kstrtos8()
      
      Include runtime testsuite (somewhat incomplete) as well.
      
      strict_strto*() become deprecated, stubbed to kstrto*() and
      eventually will be removed altogether.
      
      Use kstrto*() in code today!
      
      Note: on some archs _kstrtoul() and _kstrtol() are left in tree, even if
            they'll be unused at runtime. This is temporarily solution,
            because I don't want to hardcode list of archs where these
            functions aren't needed. Current solution with sizeof() and
            __alignof__ at least always works.
      Signed-off-by: 's avatarAlexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      33ee3b2e