lib/rbtree: add random seed

Current test use pseudo rand function with fixed seed, which means the
test data is the same pattern each time.

Add random seed parameter to randomize the test.

Link: h

lib/rbtree: add random seed

Current test use pseudo rand function with fixed seed, which means the
test data is the same pattern each time.

Add random seed parameter to randomize the test.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Wei Yang <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michel Lespinasse <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

types: move struct rcuwait into types.h

Move rcuwait struct definition into types.h so that rcuwait can be used
without including rcuwait.h which includes other headers. Without this
change mm_type

types: move struct rcuwait into types.h

Move rcuwait struct definition into types.h so that rcuwait can be used
without including rcuwait.h which includes other headers. Without this
change mm_types.h can't use rcuwait due to a the following circular
dependency:

mm_types.h -> rcuwait.h -> signal.h -> mm_types.h

Link: https://lkml.kernel.org/r/[email protected]
Suggested-by: Matthew Wilcox <[email protected]>
Signed-off-by: Suren Baghdasaryan <[email protected]>
Acked-by: Davidlohr Bueso <[email protected]>
Acked-by: Liam R. Howlett <[email protected]>
Acked-by: Lorenzo Stoakes <[email protected]>
Tested-by: Shivank Garg <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Cc: Christian Brauner <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: David Howells <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Klara Modin <[email protected]>
Cc: Lokesh Gidra <[email protected]>
Cc: Mateusz Guzik <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Pasha Tatashin <[email protected]>
Cc: "Paul E . McKenney" <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Peter Zijlstra (Intel) <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Sourav Panda <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

include: update references to include/asm-<arch>

"include/asm-<arch>" was replaced by "arch/<arch>/include/asm" a long time
ago.

Link: https://lkml.kernel.org/r/541258219b0441fa1da890e2f8458a7ac18c

include: update references to include/asm-<arch>

"include/asm-<arch>" was replaced by "arch/<arch>/include/asm" a long time
ago.

Link: https://lkml.kernel.org/r/541258219b0441fa1da890e2f8458a7ac18c2ef9.1733404444.git.geert+renesas@glider.be
Signed-off-by: Geert Uytterhoeven <[email protected]>
Cc: Andy Whitcroft <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Dwaipayan Ray <[email protected]>
Cc: Joe Perches <[email protected]>
Cc: Lukas Bulwahn <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nicolas Schier <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Yury Norov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

types: Complement the aligned types with signed 64-bit one

Some user may want to use aligned signed 64-bit type.
Provide it for them.

Signed-off-by: Andy Shevchenko <[email protected]

types: Complement the aligned types with signed 64-bit one

Some user may want to use aligned signed 64-bit type.
Provide it for them.

Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jonathan Cameron <[email protected]>

show more ...

ktime.h: move ktime_t to types.h

ktime.h pulls in quite a few headers recursively (including printk.h) -
this is going to help with trimming sched.h dependencies.

Signed-off-by: Kent Overstreet <ke

ktime.h: move ktime_t to types.h

ktime.h pulls in quite a few headers recursively (including printk.h) -
this is going to help with trimming sched.h dependencies.

Signed-off-by: Kent Overstreet <[email protected]>

show more ...

add intptr_t

Add signed intptr_t given that a) it is standard type and b) uintptr_t is
in tree.

Link: https://lkml.kernel.org/r/ed66b9e4-1fb7-45be-9bb9-d4bc291c691f@p183
Signed-off-by: Alexey Dobri

add intptr_t

Add signed intptr_t given that a) it is standard type and b) uintptr_t is
in tree.

Link: https://lkml.kernel.org/r/ed66b9e4-1fb7-45be-9bb9-d4bc291c691f@p183
Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

types: Introduce [us]128

Introduce [us]128 (when available). Unlike [us]64, ensure they are
always naturally aligned.

This also enables 128bit wide atomics (which require natural
alignment) such as

types: Introduce [us]128

Introduce [us]128 (when available). Unlike [us]64, ensure they are
always naturally aligned.

This also enables 128bit wide atomics (which require natural
alignment) such as cmpxchg128().

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Reviewed-by: Mark Rutland <[email protected]>
Acked-by: Herbert Xu <[email protected]>
Tested-by: Mark Rutland <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

atomics: Provide rcuref - scalable reference counting

atomic_t based reference counting, including refcount_t, uses
atomic_inc_not_zero() for acquiring a reference. atomic_inc_not_zero() is
implemen

atomics: Provide rcuref - scalable reference counting

atomic_t based reference counting, including refcount_t, uses
atomic_inc_not_zero() for acquiring a reference. atomic_inc_not_zero() is
implemented with a atomic_try_cmpxchg() loop. High contention of the
reference count leads to retry loops and scales badly. There is nothing to
improve on this implementation as the semantics have to be preserved.

Provide rcuref as a scalable alternative solution which is suitable for RCU
managed objects. Similar to refcount_t it comes with overflow and underflow
detection and mitigation.

rcuref treats the underlying atomic_t as an unsigned integer and partitions
this space into zones:

0x00000000 - 0x7FFFFFFF valid zone (1 .. (INT_MAX + 1) references)
0x80000000 - 0xBFFFFFFF saturation zone
0xC0000000 - 0xFFFFFFFE dead zone
0xFFFFFFFF no reference

rcuref_get() unconditionally increments the reference count with
atomic_add_negative_relaxed(). rcuref_put() unconditionally decrements the
reference count with atomic_add_negative_release().

This unconditional increment avoids the inc_not_zero() problem, but
requires a more complex implementation on the put() side when the count
drops from 0 to -1.

When this transition is detected then it is attempted to mark the reference
count dead, by setting it to the midpoint of the dead zone with a single
atomic_cmpxchg_release() operation. This operation can fail due to a
concurrent rcuref_get() elevating the reference count from -1 to 0 again.

If the unconditional increment in rcuref_get() hits a reference count which
is marked dead (or saturated) it will detect it after the fact and bring
back the reference count to the midpoint of the respective zone. The zones
provide enough tolerance which makes it practically impossible to escape
from a zone.

The racy implementation of rcuref_put() requires to protect rcuref_put()
against a grace period ending in order to prevent a subtle use after
free. As RCU is the only mechanism which allows to protect against that, it
is not possible to fully replace the atomic_inc_not_zero() based
implementation of refcount_t with this scheme.

The final drop is slightly more expensive than the atomic_dec_return()
counterpart, but that's not the case which this is optimized for. The
optimization is on the high frequeunt get()/put() pairs and their
scalability.

The performance of an uncontended rcuref_get()/put() pair where the put()
is not dropping the last reference is still on par with the plain atomic
operations, while at the same time providing overflow and underflow
detection and mitigation.

The performance of rcuref compared to plain atomic_inc_not_zero() and
atomic_dec_return() based reference counting under contention:

- Micro benchmark: All CPUs running a increment/decrement loop on an
elevated reference count, which means the 0 to -1 transition never
happens.

The performance gain depends on microarchitecture and the number of
CPUs and has been observed in the range of 1.3X to 4.7X

- Conversion of dst_entry::__refcnt to rcuref and testing with the
localhost memtier/memcached benchmark. That benchmark shows the
reference count contention prominently.

The performance gain depends on microarchitecture and the number of
CPUs and has been observed in the range of 1.1X to 2.6X over the
previous fix for the false sharing issue vs. struct
dst_entry::__refcnt.

When memtier is run over a real 1Gb network connection, there is a
small gain on top of the false sharing fix. The two changes combined
result in a 2%-5% total gain for that networked test.

Reported-by: Wangyang Guo <[email protected]>
Reported-by: Arjan Van De Ven <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

lib/sort: Add priv pointer to swap function

Adding support to have priv pointer in swap callback function.

Following the initial change on cmp callback functions [1]
and adding SWAP_WRAPPER macro t

lib/sort: Add priv pointer to swap function

Adding support to have priv pointer in swap callback function.

Following the initial change on cmp callback functions [1]
and adding SWAP_WRAPPER macro to identify sort call of sort_r.

Signed-off-by: Jiri Olsa <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Reviewed-by: Masami Hiramatsu <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

[1] 4333fb96ca10 ("media: lib/sort.c: implement sort() variant taking context argument")

show more ...

s390,alpha: switch to 64-bit ino_t

s390 and alpha are the only 64 bit architectures with a 32-bit ino_t.
Since this is quite unusual this causes bugs from time to time.

See e.g. commit ebce3eb2f7ef

s390,alpha: switch to 64-bit ino_t

s390 and alpha are the only 64 bit architectures with a 32-bit ino_t.
Since this is quite unusual this causes bugs from time to time.

See e.g. commit ebce3eb2f7ef ("ceph: fix inode number handling on
arches with 32-bit ino_t") for an example.

This (obviously) also prevents s390 and alpha to use 64-bit ino_t for
tmpfs. See commit b85a7a8bb573 ("tmpfs: disallow CONFIG_TMPFS_INODE64
on s390").

Therefore switch both s390 and alpha to 64-bit ino_t. This should only
have an effect on the ustat system call. To prevent ABI breakage
define struct ustat compatible to the old layout and change
sys_ustat() accordingly.

Acked-by: Linus Torvalds <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

show more ...

locking/atomic: Move ATOMIC_INIT into linux/types.h

This patch moves ATOMIC_INIT from asm/atomic.h into linux/types.h.
This allows users of atomic_t to use ATOMIC_INIT without having to
include atom

locking/atomic: Move ATOMIC_INIT into linux/types.h

This patch moves ATOMIC_INIT from asm/atomic.h into linux/types.h.
This allows users of atomic_t to use ATOMIC_INIT without having to
include atomic.h as that way may lead to header loops.

Signed-off-by: Herbert Xu <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Waiman Long <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

show more ...

y2038: remove unused time32 interfaces

No users remain, so kill these off before we grow new ones.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnd Bergmann

y2038: remove unused time32 interfaces

No users remain, so kill these off before we grow new ones.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Cc: Deepa Dinamani <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

y2038: uapi: change __kernel_time_t to __kernel_old_time_t

This is mainly a patch for clarification, and to let us remove
the time_t definition from the kernel to prevent new users from
creeping in

y2038: uapi: change __kernel_time_t to __kernel_old_time_t

This is mainly a patch for clarification, and to let us remove
the time_t definition from the kernel to prevent new users from
creeping in that might not be y2038-safe.

All remaining uses of 'time_t' or '__kernel_time_t' are part of
the user API that cannot be changed by that either have a
replacement or that do not suffer from the y2038 overflow.

Acked-by: Deepa Dinamani <[email protected]>
Acked-by: Christian Brauner <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>

show more ...

lib/sort: Move swap, cmp and cmp_r function types for wider use

The function types for swap, cmp and cmp_r functions are already
being in use by modules.

Move them to types.h that everybody in kern

lib/sort: Move swap, cmp and cmp_r function types for wider use

The function types for swap, cmp and cmp_r functions are already
being in use by modules.

Move them to types.h that everybody in kernel will be able to use
generic types instead of custom ones.

This adds more sense to the comment in bsearch() later on.

Link: http://lkml.kernel.org/r/[email protected]

Signed-off-by: Andy Shevchenko <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

show more ...

locking/atomic: Use s64 for atomic64_t on 64-bit

Now that all architectures use 64 consistently as the base type for the
atomic64 API, let's have the CONFIG_64BIT definition of atomic64_t use
s64 as

locking/atomic: Use s64 for atomic64_t on 64-bit

Now that all architectures use 64 consistently as the base type for the
atomic64 API, let's have the CONFIG_64BIT definition of atomic64_t use
s64 as the underlying type for atomic64_t, rather than long, matching
the generated headers.

On architectures where atomic64_read(v) is READ_ONCE(v->counter), this
patch will cause the return type of atomic64_read() to be s64.

As of this patch, the atomic64 API can be relied upon to consistently
return s64 where a value rather than boolean condition is returned. This
should make code more robust, and simpler, allowing for the removal of
casts previously required to ensure consistent types.

Signed-off-by: Mark Rutland <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

show more ...

block: remove CONFIG_LBDAF

Currently support for 64-bit sector_t and blkcnt_t is optional on 32-bit
architectures. These types are required to support block device and/or
file sizes larger than 2 T

block: remove CONFIG_LBDAF

Currently support for 64-bit sector_t and blkcnt_t is optional on 32-bit
architectures. These types are required to support block device and/or
file sizes larger than 2 TiB, and have generally defaulted to on for
a long time. Enabling the option only increases the i386 tinyconfig
size by 145 bytes, and many data structures already always use
64-bit values for their in-core and on-disk data structures anyway,
so there should not be a large change in dynamic memory usage either.

Dropping this option removes a somewhat weird non-default config that
has cause various bugs or compiler warnings when actually used.

Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

show more ...

include/linux/types.h: use "unsigned int" instead of "unsigned"

Use "unsigned int" instead of "unsigned", to make code more clear.

Link: http://lkml.kernel.org/r/1551354739-6648-1-git-send-email-wd

include/linux/types.h: use "unsigned int" instead of "unsigned"

Use "unsigned int" instead of "unsigned", to make code more clear.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: WangBo <[email protected]>
Reviewed-by: Masahiro Yamada <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

types: Remove call_rcu_bh() and call_rcu_sched()

Now that call_rcu()'s callback is not invoked until after bh-disable and
preempt-disable regions of code have completed (in addition to explicitly
ma

types: Remove call_rcu_bh() and call_rcu_sched()

Now that call_rcu()'s callback is not invoked until after bh-disable and
preempt-disable regions of code have completed (in addition to explicitly
marked RCU read-side critical sections), call_rcu() can be used in place
of call_rcu_bh() and call_rcu_sched(). This commit therefore removes
these two API members from the callback_head structure's header comment.

Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Alexey Dobriyan <[email protected]>

show more ...

include/linux/types.h: use fixed width types without double-underscore prefix

This header file is not exported. It is safe to reference types without
double-underscore prefix.

Link: http://lkml.ke

include/linux/types.h: use fixed width types without double-underscore prefix

This header file is not exported. It is safe to reference types without
double-underscore prefix.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Masahiro Yamada <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Lihao Liang <[email protected]>
Cc: Philippe Ombredanne <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

include/linux/types.h: define aligned_ types based on uapi header

<uapi/linux/types.h> has the same typedefs except that it prefixes them
with double-underscore for user space. Use them for the ker

include/linux/types.h: define aligned_ types based on uapi header

<uapi/linux/types.h> has the same typedefs except that it prefixes them
with double-underscore for user space. Use them for the kernel space
typedefs.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Lihao Liang <[email protected]>
Cc: Philippe Ombredanne <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

doc: Fix typo in rcu_head comments

Signed-off-by: Lihao Liang <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

slab, slub, slob: convert slab_flags_t to 32-bit

struct kmem_cache::flags is "unsigned long" which is unnecessary on
64-bit as no flags are defined in the higher bits.

Switch the field to 32-bit an

slab, slub, slob: convert slab_flags_t to 32-bit

struct kmem_cache::flags is "unsigned long" which is unnecessary on
64-bit as no flags are defined in the higher bits.

Switch the field to 32-bit and save some space on x86_64 until such
flags appear:

add/remove: 0/0 grow/shrink: 0/107 up/down: 0/-657 (-657)
function old new delta
sysfs_slab_add 720 719 -1
...
check_object 699 676 -23

[[email protected]: fix printk warning]
Link: http://lkml.kernel.org/r/20171021100635.GA8287@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Acked-by: Pekka Enberg <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

slab, slub, slob: add slab_flags_t

Add sparse-checked slab_flags_t for struct kmem_cache::flags (SLAB_POISON,
etc).

SLAB is bloated temporarily by switching to "unsigned long", but only
temporarily

slab, slub, slob: add slab_flags_t

Add sparse-checked slab_flags_t for struct kmem_cache::flags (SLAB_POISON,
etc).

SLAB is bloated temporarily by switching to "unsigned long", but only
temporarily.

Link: http://lkml.kernel.org/r/20171021100225.GA22428@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Acked-by: Pekka Enberg <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

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

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 <[email protected]>
Reviewed-by: Philippe Ombredanne <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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types: Update obsolete callback_head comment

The comment header for callback_head (and thus for rcu_head) states that
the bottom two bits of a pointer to these structures must be zero. This
is obso

types: Update obsolete callback_head comment

The comment header for callback_head (and thus for rcu_head) states that
the bottom two bits of a pointer to these structures must be zero. This
is obsolete: The new requirement is that only the bottom bit need be
zero. This commit therefore updates this comment.

Signed-off-by: Paul E. McKenney <[email protected]>

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