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![Greg Kroah-Hartman](/assets/img/avatar_default.png)
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: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
231 lines
6.9 KiB
C
231 lines
6.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Mutexes: blocking mutual exclusion locks
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*
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* started by Ingo Molnar:
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*
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* Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
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*
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* This file contains the main data structure and API definitions.
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*/
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#ifndef __LINUX_MUTEX_H
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#define __LINUX_MUTEX_H
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#include <asm/current.h>
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#include <linux/list.h>
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#include <linux/spinlock_types.h>
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#include <linux/linkage.h>
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#include <linux/lockdep.h>
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#include <linux/atomic.h>
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#include <asm/processor.h>
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#include <linux/osq_lock.h>
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#include <linux/debug_locks.h>
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struct ww_acquire_ctx;
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/*
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* Simple, straightforward mutexes with strict semantics:
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*
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* - only one task can hold the mutex at a time
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* - only the owner can unlock the mutex
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* - multiple unlocks are not permitted
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* - recursive locking is not permitted
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* - a mutex object must be initialized via the API
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* - a mutex object must not be initialized via memset or copying
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* - task may not exit with mutex held
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* - memory areas where held locks reside must not be freed
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* - held mutexes must not be reinitialized
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* - mutexes may not be used in hardware or software interrupt
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* contexts such as tasklets and timers
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*
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* These semantics are fully enforced when DEBUG_MUTEXES is
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* enabled. Furthermore, besides enforcing the above rules, the mutex
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* debugging code also implements a number of additional features
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* that make lock debugging easier and faster:
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*
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* - uses symbolic names of mutexes, whenever they are printed in debug output
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* - point-of-acquire tracking, symbolic lookup of function names
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* - list of all locks held in the system, printout of them
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* - owner tracking
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* - detects self-recursing locks and prints out all relevant info
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* - detects multi-task circular deadlocks and prints out all affected
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* locks and tasks (and only those tasks)
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*/
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struct mutex {
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atomic_long_t owner;
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spinlock_t wait_lock;
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#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
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struct optimistic_spin_queue osq; /* Spinner MCS lock */
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#endif
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struct list_head wait_list;
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#ifdef CONFIG_DEBUG_MUTEXES
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void *magic;
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#endif
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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struct lockdep_map dep_map;
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#endif
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};
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static inline struct task_struct *__mutex_owner(struct mutex *lock)
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{
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return (struct task_struct *)(atomic_long_read(&lock->owner) & ~0x07);
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}
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/*
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* This is the control structure for tasks blocked on mutex,
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* which resides on the blocked task's kernel stack:
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*/
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struct mutex_waiter {
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struct list_head list;
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struct task_struct *task;
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struct ww_acquire_ctx *ww_ctx;
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#ifdef CONFIG_DEBUG_MUTEXES
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void *magic;
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#endif
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};
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#ifdef CONFIG_DEBUG_MUTEXES
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#define __DEBUG_MUTEX_INITIALIZER(lockname) \
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, .magic = &lockname
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extern void mutex_destroy(struct mutex *lock);
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#else
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# define __DEBUG_MUTEX_INITIALIZER(lockname)
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static inline void mutex_destroy(struct mutex *lock) {}
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#endif
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/**
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* mutex_init - initialize the mutex
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* @mutex: the mutex to be initialized
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*
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* Initialize the mutex to unlocked state.
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*
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* It is not allowed to initialize an already locked mutex.
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*/
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#define mutex_init(mutex) \
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do { \
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static struct lock_class_key __key; \
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\
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__mutex_init((mutex), #mutex, &__key); \
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} while (0)
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
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, .dep_map = { .name = #lockname }
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#else
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# define __DEP_MAP_MUTEX_INITIALIZER(lockname)
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#endif
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#define __MUTEX_INITIALIZER(lockname) \
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{ .owner = ATOMIC_LONG_INIT(0) \
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, .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \
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, .wait_list = LIST_HEAD_INIT(lockname.wait_list) \
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__DEBUG_MUTEX_INITIALIZER(lockname) \
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__DEP_MAP_MUTEX_INITIALIZER(lockname) }
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#define DEFINE_MUTEX(mutexname) \
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struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
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extern void __mutex_init(struct mutex *lock, const char *name,
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struct lock_class_key *key);
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/**
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* mutex_is_locked - is the mutex locked
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* @lock: the mutex to be queried
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*
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* Returns 1 if the mutex is locked, 0 if unlocked.
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*/
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static inline int mutex_is_locked(struct mutex *lock)
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{
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/*
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* XXX think about spin_is_locked
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*/
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return __mutex_owner(lock) != NULL;
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}
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/*
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* See kernel/locking/mutex.c for detailed documentation of these APIs.
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* Also see Documentation/locking/mutex-design.txt.
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*/
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass);
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extern void _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock);
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extern int __must_check mutex_lock_interruptible_nested(struct mutex *lock,
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unsigned int subclass);
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extern int __must_check mutex_lock_killable_nested(struct mutex *lock,
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unsigned int subclass);
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extern void mutex_lock_io_nested(struct mutex *lock, unsigned int subclass);
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#define mutex_lock(lock) mutex_lock_nested(lock, 0)
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#define mutex_lock_interruptible(lock) mutex_lock_interruptible_nested(lock, 0)
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#define mutex_lock_killable(lock) mutex_lock_killable_nested(lock, 0)
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#define mutex_lock_io(lock) mutex_lock_io_nested(lock, 0)
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#define mutex_lock_nest_lock(lock, nest_lock) \
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do { \
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typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \
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_mutex_lock_nest_lock(lock, &(nest_lock)->dep_map); \
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} while (0)
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#else
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extern void mutex_lock(struct mutex *lock);
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extern int __must_check mutex_lock_interruptible(struct mutex *lock);
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extern int __must_check mutex_lock_killable(struct mutex *lock);
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extern void mutex_lock_io(struct mutex *lock);
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# define mutex_lock_nested(lock, subclass) mutex_lock(lock)
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# define mutex_lock_interruptible_nested(lock, subclass) mutex_lock_interruptible(lock)
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# define mutex_lock_killable_nested(lock, subclass) mutex_lock_killable(lock)
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# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
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# define mutex_lock_io_nested(lock, subclass) mutex_lock(lock)
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#endif
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/*
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* NOTE: mutex_trylock() follows the spin_trylock() convention,
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* not the down_trylock() convention!
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*
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* Returns 1 if the mutex has been acquired successfully, and 0 on contention.
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*/
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extern int mutex_trylock(struct mutex *lock);
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extern void mutex_unlock(struct mutex *lock);
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extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
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/*
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* These values are chosen such that FAIL and SUCCESS match the
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* values of the regular mutex_trylock().
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*/
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enum mutex_trylock_recursive_enum {
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MUTEX_TRYLOCK_FAILED = 0,
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MUTEX_TRYLOCK_SUCCESS = 1,
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MUTEX_TRYLOCK_RECURSIVE,
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};
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/**
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* mutex_trylock_recursive - trylock variant that allows recursive locking
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* @lock: mutex to be locked
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*
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* This function should not be used, _ever_. It is purely for hysterical GEM
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* raisins, and once those are gone this will be removed.
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*
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* Returns:
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* - MUTEX_TRYLOCK_FAILED - trylock failed,
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* - MUTEX_TRYLOCK_SUCCESS - lock acquired,
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* - MUTEX_TRYLOCK_RECURSIVE - we already owned the lock.
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*/
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static inline /* __deprecated */ __must_check enum mutex_trylock_recursive_enum
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mutex_trylock_recursive(struct mutex *lock)
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{
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if (unlikely(__mutex_owner(lock) == current))
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return MUTEX_TRYLOCK_RECURSIVE;
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return mutex_trylock(lock);
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}
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#endif /* __LINUX_MUTEX_H */
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