delta/linux.git/include/linux/cpu.h, branch proc-cmdline

Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-01-14T17:51:25+00:00

Pull x86 pti updates from Thomas Gleixner:
 "This contains:

   - a PTI bugfix to avoid setting reserved CR3 bits when PCID is
     disabled. This seems to cause issues on a virtual machine at least
     and is incorrect according to the AMD manual.

   - a PTI bugfix which disables the perf BTS facility if PTI is
     enabled. The BTS AUX buffer is not globally visible and causes the
     CPU to fault when the mapping disappears on switching CR3 to user
     space. A full fix which restores BTS on PTI is non trivial and will
     be worked on.

   - PTI bugfixes for EFI and trusted boot which make sure that the user
     space visible page table entries have the NX bit cleared

   - removal of dead code in the PTI pagetable setup functions

   - add PTI documentation

   - add a selftest for vsyscall to verify that the kernel actually
     implements what it advertises.

   - a sysfs interface to expose vulnerability and mitigation
     information so there is a coherent way for users to retrieve the
     status.

   - the initial spectre_v2 mitigations, aka retpoline:

      + The necessary ASM thunk and compiler support

      + The ASM variants of retpoline and the conversion of affected ASM
        code

      + Make LFENCE serializing on AMD so it can be used as speculation
        trap

      + The RSB fill after vmexit

   - initial objtool support for retpoline

  As I said in the status mail this is the most of the set of patches
  which should go into 4.15 except two straight forward patches still on
  hold:

   - the retpoline add on of LFENCE which waits for ACKs

   - the RSB fill after context switch

  Both should be ready to go early next week and with that we'll have
  covered the major holes of spectre_v2 and go back to normality"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits)
  x86,perf: Disable intel_bts when PTI
  security/Kconfig: Correct the Documentation reference for PTI
  x86/pti: Fix !PCID and sanitize defines
  selftests/x86: Add test_vsyscall
  x86/retpoline: Fill return stack buffer on vmexit
  x86/retpoline/irq32: Convert assembler indirect jumps
  x86/retpoline/checksum32: Convert assembler indirect jumps
  x86/retpoline/xen: Convert Xen hypercall indirect jumps
  x86/retpoline/hyperv: Convert assembler indirect jumps
  x86/retpoline/ftrace: Convert ftrace assembler indirect jumps
  x86/retpoline/entry: Convert entry assembler indirect jumps
  x86/retpoline/crypto: Convert crypto assembler indirect jumps
  x86/spectre: Add boot time option to select Spectre v2 mitigation
  x86/retpoline: Add initial retpoline support
  objtool: Allow alternatives to be ignored
  objtool: Detect jumps to retpoline thunks
  x86/pti: Make unpoison of pgd for trusted boot work for real
  x86/alternatives: Fix optimize_nops() checking
  sysfs/cpu: Fix typos in vulnerability documentation
  x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC
  ...

sysfs/cpu: Add vulnerability folder

2018-01-08T10:10:33+00:00

As the meltdown/spectre problem affects several CPU architectures, it makes
sense to have common way to express whether a system is affected by a
particular vulnerability or not. If affected the way to express the
mitigation should be common as well.

Create /sys/devices/system/cpu/vulnerabilities folder and files for
meltdown, spectre_v1 and spectre_v2.

Allow architectures to override the show function.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Konrad Rzeszutek Wilk 
Cc: Peter Zijlstra 
Cc: Will Deacon 
Cc: Dave Hansen 
Cc: Linus Torvalds 
Cc: Borislav Petkov 
Cc: David Woodhouse 
Link: https://lkml.kernel.org/r/20180107214913.096657732@linutronix.de

Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-11-14T02:23:19+00:00

Pull smp/hotplug updates from Thomas Gleixner:
 "No functional changes, just removal of obsolete and outdated defines,
  macros and documentation"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Get rid of CPU hotplug notifier leftovers
  cpu/hotplug: Remove obsolete notifier macros

cpu/hotplug: Get rid of CPU hotplug notifier leftovers

2017-11-13T09:03:53+00:00

The CPU hotplug notifiers are history. Remove the last reminders.

Reported-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

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

cpu/hotplug: Remove obsolete notifier macros

2017-10-24T08:43:52+00:00

commit 530e9b76ae8f ("cpu/hotplug: Remove obsolete cpu hotplug
register/unregister functions")' removed the below macros:

- #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
- #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
- #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */

But "CPU_UP_CANCELED_FROZEN, CPU_DOWN_PREPARE_FROZEN and
CPU_DOWN_FAILED_FROZEN" still refer to them, and nobody uses these "FROZEN"
macros now, so remove them too.

Signed-off-by: Yanjiang Jin 
Signed-off-by: Thomas Gleixner 
Cc: peterz@infradead.org
Cc: bigeasy@linutronix.de
Cc: jinyanjiang@gmail.com
Link: https://lkml.kernel.org/r/20171024062341.179678-1-yanjiang.jin@windriver.com

cpu/hotplug: Convert hotplug locking to percpu rwsem

2017-05-26T08:10:46+00:00

There are no more (known) nested calls to get_online_cpus() and all
observed lock ordering problems have been addressed.

Replace the magic nested 'rwsem' hackery with a percpu-rwsem.

Signed-off-by: Thomas Gleixner 
Tested-by: Paul E. McKenney 
Acked-by: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Sebastian Siewior 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/20170524081549.447014063@linutronix.de

cpu/hotplug: Provide lockdep_assert_cpus_held()

2017-05-26T08:10:35+00:00

Provide a stub function which can be used in places where existing
get_online_cpus() calls are moved to call sites.

This stub is going to be filled by the final conversion of the hotplug
locking mechanism to a percpu rwsem.

Signed-off-by: Thomas Gleixner 
Tested-by: Paul E. McKenney 
Acked-by: Paul E. McKenney 
Acked-by: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Sebastian Siewior 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/20170524081547.161282442@linutronix.de

cpu/hotplug: Provide cpus_read|write_[un]lock()

2017-05-26T08:10:34+00:00

The counting 'rwsem' hackery of get|put_online_cpus() is going to be
replaced by percpu rwsem.

Rename the functions to make it clear that it's locking and not some
refcount style interface. These new functions will be used for the
preparatory patches which make the code ready for the percpu rwsem
conversion.

Rename all instances in the cpu hotplug code while at it.

Signed-off-by: Thomas Gleixner 
Tested-by: Paul E. McKenney 
Acked-by: Paul E. McKenney 
Acked-by: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Sebastian Siewior 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/20170524081547.080397752@linutronix.de

sched/headers: Prepare to move _init() prototypes from to

2017-03-02T07:42:40+00:00

But first introduce a trivial header and update usage sites.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar