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
      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>
  2. 19 Oct, 2017 1 commit
    • Borislav Petkov's avatar
      locking/static_keys: Improve uninitialized key warning · 5cdda511
      Borislav Petkov authored
      Right now it says:
        static_key_disable_cpuslocked used before call to jump_label_init
        ------------[ cut here ]------------
        WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:161 static_key_disable_cpuslocked+0x68/0x70
        Modules linked in:
        CPU: 0 PID: 0 Comm: swapper Not tainted 4.14.0-rc5+ #1
        Hardware name: SGI.COM C2112-4GP3/X10DRT-P-Series, BIOS 2.0a 05/09/2016
        task: ffffffff81c0e480 task.stack: ffffffff81c00000
        RIP: 0010:static_key_disable_cpuslocked+0x68/0x70
        RSP: 0000:ffffffff81c03ef0 EFLAGS: 00010096 ORIG_RAX: 0000000000000000
        RAX: 0000000000000041 RBX: ffffffff81c32680 RCX: ffffffff81c5cbf8
        RDX: 0000000000000001 RSI: 0000000000000092 RDI: 0000000000000002
        RBP: ffff88807fffd240 R08: 726f666562206465 R09: 0000000000000136
        R10: 0000000000000000 R11: 696e695f6c656261 R12: ffffffff82158900
        R13: ffffffff8215f760 R14: 0000000000000001 R15: 0000000000000008
        FS:  0000000000000000(0000) GS:ffff883f7f400000(0000) knlGS:0000000000000000
        CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
        CR2: ffff88807ffff000 CR3: 0000000001c09000 CR4: 00000000000606b0
        Call Trace:
         ? load_ucode_intel_bsp+0x11/0x2d
        Code: 48 c7 c7 a0 15 cf 81 e9 47 53 4b 00 48 89 df e8 5f fc ff ff eb e8 48 c7 c6 \
      	c0 97 83 81 48 c7 c7 d0 ff a2 81 31 c0 e8 c5 9d f5 ff <0f> ff eb a7 0f ff eb \
      	b0 e8 eb a2 4b 00 53 48 89 fb e8 42 0e f0
      but it doesn't tell me which key it is. So dump the key's name too:
        static_key_disable_cpuslocked(): static key 'virt_spin_lock_key' used before call to jump_label_init()
      And that makes pinpointing which key is causing that a lot easier.
       include/linux/jump_label.h           |   14 +++++++-------
       include/linux/jump_label_ratelimit.h |    6 +++---
       kernel/jump_label.c                  |   14 +++++++-------
       3 files changed, 17 insertions(+), 17 deletions(-)
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Reviewed-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
      Cc: Jason Baron <jbaron@akamai.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20171018152428.ffjgak4o25f7ept6@pd.tnicSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
  3. 12 Jan, 2017 1 commit
  4. 19 Oct, 2013 1 commit
    • Hannes Frederic Sowa's avatar
      static_key: WARN on usage before jump_label_init was called · c4b2c0c5
      Hannes Frederic Sowa authored
      Usage of the static key primitives to toggle a branch must not be used
      before jump_label_init() is called from init/main.c. jump_label_init
      reorganizes and wires up the jump_entries so usage before that could
      have unforeseen consequences.
      Following primitives are now checked for correct use:
      * static_key_slow_inc
      * static_key_slow_dec
      * static_key_slow_dec_deferred
      * jump_label_rate_limit
      The x86 architecture already checks this by testing if the default_nop
      was already replaced with an optimal nop or with a branch instruction. It
      will panic then. Other architectures don't check for this.
      Because we need to relax this check for the x86 arch to allow code to
      transition from default_nop to the enabled state and other architectures
      did not check for this at all this patch introduces checking on the
      static_key primitives in a non-arch dependent manner.
      All checked functions are considered slow-path so the additional check
      does no harm to performance.
      The warnings are best observed with earlyprintk.
      Based on a patch from Andi Kleen.
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Andi Kleen <andi@firstfloor.org>
      Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
  5. 09 Aug, 2013 1 commit