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. 10 Aug, 2017 1 commit
    • Peter Zijlstra's avatar
      locking/lockdep: Avoid creating redundant links · ae813308
      Peter Zijlstra authored
      Two boots + a make defconfig, the first didn't have the redundant bit
      in, the second did:
       lock-classes:                         1168       1169 [max: 8191]
       direct dependencies:                  7688       5812 [max: 32768]
       indirect dependencies:               25492      25937
       all direct dependencies:            220113     217512
       dependency chains:                    9005       9008 [max: 65536]
       dependency chain hlocks:             34450      34366 [max: 327680]
       in-hardirq chains:                      55         51
       in-softirq chains:                     371        378
       in-process chains:                    8579       8579
       stack-trace entries:                108073      88474 [max: 524288]
       combined max dependencies:       178738560  169094640
       max locking depth:                      15         15
       max bfs queue depth:                   320        329
       cyclic checks:                        9123       9190
       redundant checks:                                5046
       redundant links:                                 1828
       find-mask forwards checks:            2564       2599
       find-mask backwards checks:          39521      39789
      So it saves nearly 2k links and a fair chunk of stack-trace entries, but
      as expected, makes no real difference on the indirect dependencies.
      At the same time, you see the max BFS depth increase, which is also
      expected, although it could easily be boot variance -- these numbers are
      not entirely stable between boots.
      The down side is that the cycles in the graph become larger and thus
      the reports harder to read.
      XXX: do we want this as a CONFIG variable, implied by LOCKDEP_SMALL?
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Byungchul Park <byungchul.park@lge.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Michal Hocko <mhocko@kernel.org>
      Cc: Nikolay Borisov <nborisov@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: akpm@linux-foundation.org
      Cc: boqun.feng@gmail.com
      Cc: iamjoonsoo.kim@lge.com
      Cc: kernel-team@lge.com
      Cc: kirill@shutemov.name
      Cc: npiggin@gmail.com
      Cc: walken@google.com
      Link: http://lkml.kernel.org/r/20170303091338.GH6536@twins.programming.kicks-ass.netSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
  3. 24 Dec, 2016 1 commit
  4. 23 Apr, 2016 1 commit
    • Peter Zijlstra's avatar
      lockdep: Fix lock_chain::base size · 75dd602a
      Peter Zijlstra authored
      lock_chain::base is used to store an index into the chain_hlocks[]
      array, however that array contains more elements than can be indexed
      using the u16.
      Change the lock_chain structure to use a bitfield to encode the data
      it needs and add BUILD_BUG_ON() assertions to check the fields are
      wide enough.
      Also, for DEBUG_LOCKDEP, assert that we don't run out of elements of
      that array; as that would wreck the collision detectoring.
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Alfredo Alvarez Fernandez <alfredoalvarezfernandez@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Sedat Dilek <sedat.dilek@gmail.com>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20160330093659.GS3408@twins.programming.kicks-ass.netSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
  5. 23 Nov, 2015 1 commit
    • Peter Zijlstra's avatar
      treewide: Remove old email address · 90eec103
      Peter Zijlstra authored
      There were still a number of references to my old Red Hat email
      address in the kernel source. Remove these while keeping the
      Red Hat copyright notices intact.
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
  6. 07 Jun, 2015 1 commit
  7. 11 Nov, 2013 1 commit
  8. 06 Nov, 2013 1 commit
  9. 09 Oct, 2013 1 commit
  10. 24 Oct, 2012 1 commit
  11. 31 Oct, 2011 1 commit
    • Paul Gortmaker's avatar
      kernel: Map most files to use export.h instead of module.h · 9984de1a
      Paul Gortmaker authored
      The changed files were only including linux/module.h for the
      EXPORT_SYMBOL infrastructure, and nothing else.  Revector them
      onto the isolated export header for faster compile times.
      Nothing to see here but a whole lot of instances of:
        -#include <linux/module.h>
        +#include <linux/export.h>
      This commit is only changing the kernel dir; next targets
      will probably be mm, fs, the arch dirs, etc.
      Signed-off-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
  12. 23 Mar, 2011 1 commit
  13. 10 Nov, 2010 1 commit
  14. 05 Apr, 2010 1 commit
    • Frederic Weisbecker's avatar
      lockstat: Make lockstat counting per cpu · bd6d29c2
      Frederic Weisbecker authored
      Locking statistics are implemented using global atomic
      variables. This is usually fine unless some path write them very
      This is the case for the function and function graph tracers
      that disable irqs for each entry saved (except if the function
      tracer is in preempt disabled only mode).
      And calls to local_irq_save/restore() increment
      hardirqs_on_events and hardirqs_off_events stats (or similar
      stats for redundant versions).
      Incrementing these global vars for each function ends up in too
      much cache bouncing if lockstats are enabled.
      To solve this, implement the debug_atomic_*() operations using
      per cpu vars.
       -v2: Use per_cpu() instead of get_cpu_var() to fetch the desired
            cpu vars on debug_atomic_read()
       -v3: Store the stats in a structure. No need for local_t as we
            are NMI/irq safe.
       -v4: Fix tons of build errors. I thought I had tested it but I
            probably forgot to select the relevant config.
      Suggested-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <1270505417-8144-1-git-send-regression-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Steven Rostedt <rostedt@goodmis.org>
  15. 23 Sep, 2009 1 commit
  16. 29 Aug, 2009 1 commit
  17. 17 Aug, 2009 5 commits
  18. 07 Aug, 2009 1 commit
  19. 02 Aug, 2009 1 commit
    • Ingo Molnar's avatar
      lockdep: Fix BFS build · bbfa2622
      Ingo Molnar authored
        kernel/built-in.o: In function `lockdep_stats_show':
        lockdep_proc.c:(.text+0x48202): undefined reference to `max_bfs_queue_depth'
      As max_bfs_queue_depth is only available under
      Cc: Ming Lei <tom.leiming@gmail.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <new-submission>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
  20. 24 Jul, 2009 1 commit
  21. 14 Feb, 2009 4 commits
    • Peter Zijlstra's avatar
      lockstat: warn about disabled lock debugging · 9833f8cb
      Peter Zijlstra authored
      Avoid confusion and clearly state lock debugging got disabled.
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    • Peter Zijlstra's avatar
      lockdep: get_user_chars() redo · f510b233
      Peter Zijlstra authored
      Generic, states independent, get_user_chars().
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    • Peter Zijlstra's avatar
      lockdep: sanitize bit names · 4fc95e86
      Peter Zijlstra authored
      s/\(LOCKF\?_ENABLED_[^ ]*\)S\(_READ\)\?\>/\1\2/g
      So that the USED_IN and ENABLED have the same names.
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    • Nick Piggin's avatar
      lockdep: annotate reclaim context (__GFP_NOFS) · cf40bd16
      Nick Piggin authored
      Here is another version, with the incremental patch rolled up, and
      added reclaim context annotation to kswapd, and allocation tracing
      to slab allocators (which may only ever reach the page allocator
      in rare cases, so it is good to put annotations here too).
      Haven't tested this version as such, but it should be getting closer
      to merge worthy ;)
      After noticing some code in mm/filemap.c accidentally perform a __GFP_FS
      allocation when it should not have been, I thought it might be a good idea to
      try to catch this kind of thing with lockdep.
      I coded up a little idea that seems to work. Unfortunately the system has to
      actually be in __GFP_FS page reclaim, then take the lock, before it will mark
      it. But at least that might still be some orders of magnitude more common
      (and more debuggable) than an actual deadlock condition, so we have some
      improvement I hope (the concept is no less complete than discovery of a lock's
      interrupt contexts).
      I guess we could even do the same thing with __GFP_IO (normal reclaim), and
      even GFP_NOIO locks too... but filesystems will have the most locks and fiddly
      code paths, so let's start there and see how it goes.
      It *seems* to work. I did a quick test.
      [ INFO: inconsistent lock state ]
      2.6.28-rc6-00007-ged313489-dirty #26
      inconsistent {in-reclaim-W} -> {ov-reclaim-W} usage.
      modprobe/8526 [HC0[0]:SC0[0]:HE1:SE1] takes:
       (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd]
      {in-reclaim-W} state was registered at:
        [<ffffffff80267bdb>] __lock_acquire+0x75b/0x1a60
        [<ffffffff80268f71>] lock_acquire+0x91/0xc0
        [<ffffffff8070f0e1>] mutex_lock_nested+0xb1/0x310
        [<ffffffffa002002b>] brd_init+0x2b/0x216 [brd]
        [<ffffffff8020903b>] _stext+0x3b/0x170
        [<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0
        [<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b
        [<ffffffffffffffff>] 0xffffffffffffffff
      irq event stamp: 3929
      hardirqs last  enabled at (3929): [<ffffffff8070f2b5>] mutex_lock_nested+0x285/0x310
      hardirqs last disabled at (3928): [<ffffffff8070f089>] mutex_lock_nested+0x59/0x310
      softirqs last  enabled at (3732): [<ffffffff8061f623>] sk_filter+0x83/0xe0
      softirqs last disabled at (3730): [<ffffffff8061f5b6>] sk_filter+0x16/0xe0
      other info that might help us debug this:
      1 lock held by modprobe/8526:
       #0:  (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd]
      stack backtrace:
      Pid: 8526, comm: modprobe Not tainted 2.6.28-rc6-00007-ged313489-dirty #26
      Call Trace:
       [<ffffffff80265483>] print_usage_bug+0x193/0x1d0
       [<ffffffff80266530>] mark_lock+0xaf0/0xca0
       [<ffffffff80266735>] mark_held_locks+0x55/0xc0
       [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
       [<ffffffff802667ca>] trace_reclaim_fs+0x2a/0x60
       [<ffffffff80285005>] __alloc_pages_internal+0x475/0x580
       [<ffffffff8070f29e>] ? mutex_lock_nested+0x26e/0x310
       [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
       [<ffffffffa002006a>] brd_init+0x6a/0x216 [brd]
       [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
       [<ffffffff8020903b>] _stext+0x3b/0x170
       [<ffffffff8070f8b9>] ? mutex_unlock+0x9/0x10
       [<ffffffff8070f83d>] ? __mutex_unlock_slowpath+0x10d/0x180
       [<ffffffff802669ec>] ? trace_hardirqs_on_caller+0x12c/0x190
       [<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0
       [<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
  22. 20 Oct, 2008 1 commit
  23. 23 Sep, 2008 1 commit
  24. 26 Aug, 2008 1 commit
    • Joe Korty's avatar
      lockstat: fix numerical output rounding error · 2189459d
      Joe Korty authored
      Fix rounding error in /proc/lock_stat numerical output.
      On occasion the two digit fractional part contains the three
      digit value '100'.  This is due to a bug in the rounding algorithm
      which pushes values in the range '95..99' to '100' rather than
      to '00' + an increment to the integer part.  For example,
      	- 123456.100      old display
      	+ 123457.00	  new display
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
  25. 15 Aug, 2008 1 commit
  26. 11 Aug, 2008 1 commit
  27. 31 Jul, 2008 1 commit
    • David Miller's avatar
      lockdep: fix combinatorial explosion in lock subgraph traversal · 419ca3f1
      David Miller authored
      When we traverse the graph, either forwards or backwards, we
      are interested in whether a certain property exists somewhere
      in a node reachable in the graph.
      Therefore it is never necessary to traverse through a node more
      than once to get a correct answer to the given query.
      Take advantage of this property using a global ID counter so that we
      need not clear all the markers in all the lock_class entries before
      doing a traversal.  A new ID is choosen when we start to traverse, and
      we continue through a lock_class only if it's ID hasn't been marked
      with the new value yet.
      This short-circuiting is essential especially for high CPU count
      systems.  The scheduler has a runqueue per cpu, and needs to take
      two runqueue locks at a time, which leads to long chains of
      backwards and forwards subgraphs from these runqueue lock nodes.
      Without the short-circuit implemented here, a graph traversal on
      a runqueue lock can take up to (1 << (N - 1)) checks on a system
      with N cpus.
      For anything more than 16 cpus or so, lockdep will eventually bring
      the machine to a complete standstill.
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
  28. 23 Jun, 2008 1 commit
  29. 20 Jun, 2008 1 commit
  30. 13 Jun, 2008 1 commit
  31. 29 Apr, 2008 1 commit
  32. 11 Oct, 2007 1 commit
    • Tim Pepper's avatar
      lockdep: Avoid /proc/lockdep & lock_stat infinite output · 94c61c0a
      Tim Pepper authored
      Both /proc/lockdep and /proc/lock_stat output may loop infinitely.
      When a read() requests an amount of data smaller than the amount of data
      that the seq_file's foo_show() outputs, the output starts looping and
      outputs the "stuck" element's data infinitely.  There may be multiple
      sequential calls to foo_start(), foo_next()/foo_show(), and foo_stop()
      for a single open with sequential read of the file.  The _start() does not
      have to start with the 0th element and _show() might be called multiple
      times in a row for the same element for a given open/read of the seq_file.
      Also header output should not be happening in _start().  All output should
      be in _show(), which SEQ_START_TOKEN is meant to help.  Having output in
      _start() may also negatively impact seq_file's seq_read() and traverse()
      Signed-off-by: default avatarTim Pepper <lnxninja@linux.vnet.ibm.com>
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Al Viro <viro@ftp.linux.org.uk>
  33. 31 Jul, 2007 1 commit