02 Nov, 2017

1 commit

  • 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
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

13 Sep, 2012

1 commit

  • ed3e694d "move exit_task_work() past exit_files() et.al" destroyed
    the add/exit synchronization we had, the caller itself should ensure
    task_work_add() can't race with the exiting task.

    However, this is not convenient/simple, and the only user which tries
    to do this is buggy (see the next patch). Unless the task is current,
    there is simply no way to do this in general.

    Change exit_task_work()->task_work_run() to use the dummy "work_exited"
    entry to let task_work_add() know it should fail.

    Signed-off-by: Oleg Nesterov
    Signed-off-by: Peter Zijlstra
    Cc: Al Viro
    Cc: Linus Torvalds
    Cc: Andrew Morton
    Cc: Thomas Gleixner
    Link: http://lkml.kernel.org/r/20120826191211.GA4228@redhat.com
    Signed-off-by: Ingo Molnar

    Oleg Nesterov
     

23 Jul, 2012

3 commits


24 May, 2012

1 commit

  • Provide a simple mechanism that allows running code in the (nonatomic)
    context of the arbitrary task.

    The caller does task_work_add(task, task_work) and this task executes
    task_work->func() either from do_notify_resume() or from do_exit(). The
    callback can rely on PF_EXITING to detect the latter case.

    "struct task_work" can be embedded in another struct, still it has "void
    *data" to handle the most common/simple case.

    This allows us to kill the ->replacement_session_keyring hack, and
    potentially this can have more users.

    Performance-wise, this adds 2 "unlikely(!hlist_empty())" checks into
    tracehook_notify_resume() and do_exit(). But at the same time we can
    remove the "replacement_session_keyring != NULL" checks from
    arch/*/signal.c and exit_creds().

    Note: task_work_add/task_work_run abuses ->pi_lock. This is only because
    this lock is already used by lookup_pi_state() to synchronize with
    do_exit() setting PF_EXITING. Fortunately the scope of this lock in
    task_work.c is really tiny, and the code is unlikely anyway.

    Signed-off-by: Oleg Nesterov
    Acked-by: David Howells
    Cc: Thomas Gleixner
    Cc: Richard Kuo
    Cc: Linus Torvalds
    Cc: Alexander Gordeev
    Cc: Chris Zankel
    Cc: David Smith
    Cc: "Frank Ch. Eigler"
    Cc: Geert Uytterhoeven
    Cc: Larry Woodman
    Cc: Peter Zijlstra
    Cc: Tejun Heo
    Cc: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Al Viro

    Oleg Nesterov