License cleanup: add SPDX GPL-2.0 license identifier to files with no license
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>
2017-11-01 22:07:57 +08:00
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/* SPDX-License-Identifier: GPL-2.0 */
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2016-03-18 05:21:45 +08:00
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#include <linux/gfp.h>
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#include <linux/types.h>
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#include <linux/radix-tree.h>
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#include <linux/rcupdate.h>
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struct item {
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2018-05-19 07:08:58 +08:00
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struct rcu_head rcu_head;
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2016-03-18 05:21:45 +08:00
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unsigned long index;
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2016-12-15 07:08:23 +08:00
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unsigned int order;
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2016-03-18 05:21:45 +08:00
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};
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2016-12-15 07:08:23 +08:00
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struct item *item_create(unsigned long index, unsigned int order);
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2016-03-18 05:21:45 +08:00
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int item_insert(struct radix_tree_root *root, unsigned long index);
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radix tree test suite: multi-order iteration race
Add a test which shows a race in the multi-order iteration code. This
test reliably hits the race in under a second on my machine, and is the
result of a real bug report against kernel a production v4.15 based
kernel (4.15.6-300.fc27.x86_64). With a real kernel this issue is hit
when using order 9 PMD DAX radix tree entries.
The race has to do with how we tear down multi-order sibling entries
when we are removing an item from the tree. Remember that an order 2
entry looks like this:
struct radix_tree_node.slots[] = [entry][sibling][sibling][sibling]
where 'entry' is in some slot in the struct radix_tree_node, and the
three slots following 'entry' contain sibling pointers which point back
to 'entry.'
When we delete 'entry' from the tree, we call :
radix_tree_delete()
radix_tree_delete_item()
__radix_tree_delete()
replace_slot()
replace_slot() first removes the siblings in order from the first to the
last, then at then replaces 'entry' with NULL. This means that for a
brief period of time we end up with one or more of the siblings removed,
so:
struct radix_tree_node.slots[] = [entry][NULL][sibling][sibling]
This causes an issue if you have a reader iterating over the slots in
the tree via radix_tree_for_each_slot() while only under
rcu_read_lock()/rcu_read_unlock() protection. This is a common case in
mm/filemap.c.
The issue is that when __radix_tree_next_slot() => skip_siblings() tries
to skip over the sibling entries in the slots, it currently does so with
an exact match on the slot directly preceding our current slot.
Normally this works:
V preceding slot
struct radix_tree_node.slots[] = [entry][sibling][sibling][sibling]
^ current slot
This lets you find the first sibling, and you skip them all in order.
But in the case where one of the siblings is NULL, that slot is skipped
and then our sibling detection is interrupted:
V preceding slot
struct radix_tree_node.slots[] = [entry][NULL][sibling][sibling]
^ current slot
This means that the sibling pointers aren't recognized since they point
all the way back to 'entry', so we think that they are normal internal
radix tree pointers. This causes us to think we need to walk down to a
struct radix_tree_node starting at the address of 'entry'.
In a real running kernel this will crash the thread with a GP fault when
you try and dereference the slots in your broken node starting at
'entry'.
In the radix tree test suite this will be caught by the address
sanitizer:
==27063==ERROR: AddressSanitizer: heap-buffer-overflow on address
0x60c0008ae400 at pc 0x00000040ce4f bp 0x7fa89b8fcad0 sp 0x7fa89b8fcac0
READ of size 8 at 0x60c0008ae400 thread T3
#0 0x40ce4e in __radix_tree_next_slot /home/rzwisler/project/linux/tools/testing/radix-tree/radix-tree.c:1660
#1 0x4022cc in radix_tree_next_slot linux/../../../../include/linux/radix-tree.h:567
#2 0x4022cc in iterator_func /home/rzwisler/project/linux/tools/testing/radix-tree/multiorder.c:655
#3 0x7fa8a088d50a in start_thread (/lib64/libpthread.so.0+0x750a)
#4 0x7fa8a03bd16e in clone (/lib64/libc.so.6+0xf516e)
Link: http://lkml.kernel.org/r/20180503192430.7582-5-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: CR, Sapthagirish <sapthagirish.cr@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-19 07:09:01 +08:00
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void item_sanity(struct item *item, unsigned long index);
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2018-08-21 03:48:46 +08:00
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void item_free(struct item *item, unsigned long index);
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2016-03-18 05:21:45 +08:00
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int item_delete(struct radix_tree_root *root, unsigned long index);
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2018-09-23 03:34:28 +08:00
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int item_delete_rcu(struct xarray *xa, unsigned long index);
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2016-03-18 05:21:45 +08:00
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struct item *item_lookup(struct radix_tree_root *root, unsigned long index);
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void item_check_present(struct radix_tree_root *root, unsigned long index);
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void item_check_absent(struct radix_tree_root *root, unsigned long index);
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void item_gang_check_present(struct radix_tree_root *root,
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unsigned long start, unsigned long nr,
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int chunk, int hop);
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void item_full_scan(struct radix_tree_root *root, unsigned long start,
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unsigned long nr, int chunk);
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void item_kill_tree(struct radix_tree_root *root);
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2018-08-18 19:09:22 +08:00
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int tag_tagged_items(struct xarray *, unsigned long start, unsigned long end,
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unsigned batch, xa_mark_t iftag, xa_mark_t thentag);
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2016-12-15 07:08:52 +08:00
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2017-11-08 03:57:46 +08:00
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void xarray_tests(void);
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2016-03-18 05:21:45 +08:00
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void tag_check(void);
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2016-05-21 08:02:14 +08:00
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void multiorder_checks(void);
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2016-12-15 07:09:10 +08:00
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void iteration_test(unsigned order, unsigned duration);
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2020-03-13 05:29:11 +08:00
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void iteration_test2(unsigned duration);
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2016-12-15 07:08:14 +08:00
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void benchmark(void);
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2016-12-20 23:27:56 +08:00
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void idr_checks(void);
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2018-06-19 04:59:29 +08:00
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void ida_tests(void);
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2016-03-18 05:21:45 +08:00
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struct item *
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item_tag_set(struct radix_tree_root *root, unsigned long index, int tag);
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struct item *
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item_tag_clear(struct radix_tree_root *root, unsigned long index, int tag);
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int item_tag_get(struct radix_tree_root *root, unsigned long index, int tag);
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void tree_verify_min_height(struct radix_tree_root *root, int maxindex);
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void verify_tag_consistency(struct radix_tree_root *root, unsigned int tag);
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extern int nr_allocated;
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/* Normally private parts of lib/radix-tree.c */
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2016-12-15 07:08:49 +08:00
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struct radix_tree_node *entry_to_node(void *ptr);
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2016-05-21 08:02:55 +08:00
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void radix_tree_dump(struct radix_tree_root *root);
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2016-03-18 05:21:45 +08:00
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int root_tag_get(struct radix_tree_root *root, unsigned int tag);
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2016-05-21 08:03:16 +08:00
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unsigned long node_maxindex(struct radix_tree_node *);
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unsigned long shift_maxindex(unsigned int shift);
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2016-12-15 07:08:05 +08:00
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int radix_tree_cpu_dead(unsigned int cpu);
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2016-12-15 07:09:04 +08:00
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extern struct radix_tree_preload radix_tree_preloads;
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