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

Pull locking updates from Ingo Molnar:
 "The main changes in the locking subsystem in this cycle were:

   - Add the Linux Kernel Memory Consistency Model (LKMM) subsystem,
     which is an an array of tools in tools/memory-model/ that formally
     describe the Linux memory coherency model (a.k.a.
     Documentation/memory-barriers.txt), and also produce 'litmus tests'
     in form of kernel code which can be directly executed and tested.

     Here's a high level background article about an earlier version of
     this work on LWN.net:

        https://lwn.net/Articles/718628/

     The design principles:

      "There is reason to believe that Documentation/memory-barriers.txt
       could use some help, and a major purpose of this patch is to
       provide that help in the form of a design-time tool that can
       produce all valid executions of a small fragment of concurrent
       Linux-kernel code, which is called a "litmus test". This tool's
       functionality is roughly similar to a full state-space search.
       Please note that this is a design-time tool, not useful for
       regression testing. However, we hope that the underlying
       Linux-kernel memory model will be incorporated into other tools
       capable of analyzing large bodies of code for regression-testing
       purposes."

     [...]

      "A second tool is klitmus7, which converts litmus tests to
       loadable kernel modules for direct testing. As with herd7, the
       klitmus7 code is freely available from

         http://diy.inria.fr/sources/index.html

       (and via "git" at https://github.com/herd/herdtools7)"

     [...]

     Credits go to:

      "This patch was the result of a most excellent collaboration
       founded by Jade Alglave and also including Alan Stern, Andrea
       Parri, and Luc Maranget."

     ... and to the gents listed in the MAINTAINERS entry:

        LINUX KERNEL MEMORY CONSISTENCY MODEL (LKMM)
        M:      Alan Stern <stern@rowland.harvard.edu>
        M:      Andrea Parri <parri.andrea@gmail.com>
        M:      Will Deacon <will.deacon@arm.com>
        M:      Peter Zijlstra <peterz@infradead.org>
        M:      Boqun Feng <boqun.feng@gmail.com>
        M:      Nicholas Piggin <npiggin@gmail.com>
        M:      David Howells <dhowells@redhat.com>
        M:      Jade Alglave <j.alglave@ucl.ac.uk>
        M:      Luc Maranget <luc.maranget@inria.fr>
        M:      "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

     The LKMM project already found several bugs in Linux locking
     primitives and improved the understanding and the documentation of
     the Linux memory model all around.

   - Add KASAN instrumentation to atomic APIs (Dmitry Vyukov)

   - Add RWSEM API debugging and reorganize the lock debugging Kconfig
     (Waiman Long)

   - ... misc cleanups and other smaller changes"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
  locking/Kconfig: Restructure the lock debugging menu
  locking/Kconfig: Add LOCK_DEBUGGING_SUPPORT to make it more readable
  locking/rwsem: Add DEBUG_RWSEMS to look for lock/unlock mismatches
  lockdep: Make the lock debug output more useful
  locking/rtmutex: Handle non enqueued waiters gracefully in remove_waiter()
  locking/atomic, asm-generic, x86: Add comments for atomic instrumentation
  locking/atomic, asm-generic: Add KASAN instrumentation to atomic operations
  locking/atomic/x86: Switch atomic.h to use atomic-instrumented.h
  locking/atomic, asm-generic: Add asm-generic/atomic-instrumented.h
  locking/xchg/alpha: Remove superfluous memory barriers from the _local() variants
  tools/memory-model: Finish the removal of rb-dep, smp_read_barrier_depends(), and lockless_dereference()
  tools/memory-model: Add documentation of new litmus test
  tools/memory-model: Remove mention of docker/gentoo image
  locking/memory-barriers: De-emphasize smp_read_barrier_depends() some more
  locking/lockdep: Show unadorned pointers
  mutex: Drop linkage.h from mutex.h
  tools/memory-model: Remove rb-dep, smp_read_barrier_depends, and lockless_dereference
  tools/memory-model: Convert underscores to hyphens
  tools/memory-model: Add a S lock-based external-view litmus test
  tools/memory-model: Add required herd7 version to README file
  ...

1 files changed, 82 insertions, 68 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 64155e310a9f..4f7b3a11eb4d 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1034,69 +1034,20 @@ config DEBUG_PREEMPT
 
 menu "Lock Debugging (spinlocks, mutexes, etc...)"
 
-config DEBUG_RT_MUTEXES
-	bool "RT Mutex debugging, deadlock detection"
-	depends on DEBUG_KERNEL && RT_MUTEXES
-	help
-	 This allows rt mutex semantics violations and rt mutex related
-	 deadlocks (lockups) to be detected and reported automatically.
-
-config DEBUG_SPINLOCK
-	bool "Spinlock and rw-lock debugging: basic checks"
-	depends on DEBUG_KERNEL
-	select UNINLINE_SPIN_UNLOCK
-	help
-	  Say Y here and build SMP to catch missing spinlock initialization
-	  and certain other kinds of spinlock errors commonly made.  This is
-	  best used in conjunction with the NMI watchdog so that spinlock
-	  deadlocks are also debuggable.
-
-config DEBUG_MUTEXES
-	bool "Mutex debugging: basic checks"
-	depends on DEBUG_KERNEL
-	help
-	 This feature allows mutex semantics violations to be detected and
-	 reported.
-
-config DEBUG_WW_MUTEX_SLOWPATH
-	bool "Wait/wound mutex debugging: Slowpath testing"
-	depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
-	select DEBUG_LOCK_ALLOC
-	select DEBUG_SPINLOCK
-	select DEBUG_MUTEXES
-	help
-	 This feature enables slowpath testing for w/w mutex users by
-	 injecting additional -EDEADLK wound/backoff cases. Together with
-	 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
-	 will test all possible w/w mutex interface abuse with the
-	 exception of simply not acquiring all the required locks.
-	 Note that this feature can introduce significant overhead, so
-	 it really should not be enabled in a production or distro kernel,
-	 even a debug kernel.  If you are a driver writer, enable it.  If
-	 you are a distro, do not.
-
-config DEBUG_LOCK_ALLOC
-	bool "Lock debugging: detect incorrect freeing of live locks"
-	depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
-	select DEBUG_SPINLOCK
-	select DEBUG_MUTEXES
-	select DEBUG_RT_MUTEXES if RT_MUTEXES
-	select LOCKDEP
-	help
-	 This feature will check whether any held lock (spinlock, rwlock,
-	 mutex or rwsem) is incorrectly freed by the kernel, via any of the
-	 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
-	 vfree(), etc.), whether a live lock is incorrectly reinitialized via
-	 spin_lock_init()/mutex_init()/etc., or whether there is any lock
-	 held during task exit.
+config LOCK_DEBUGGING_SUPPORT
+	bool
+	depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
+	default y
 
 config PROVE_LOCKING
 	bool "Lock debugging: prove locking correctness"
-	depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
+	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
 	select LOCKDEP
 	select DEBUG_SPINLOCK
 	select DEBUG_MUTEXES
 	select DEBUG_RT_MUTEXES if RT_MUTEXES
+	select DEBUG_RWSEMS if RWSEM_SPIN_ON_OWNER
+	select DEBUG_WW_MUTEX_SLOWPATH
 	select DEBUG_LOCK_ALLOC
 	select TRACE_IRQFLAGS
 	default n
@@ -1134,20 +1085,9 @@ config PROVE_LOCKING
 
 	 For more details, see Documentation/locking/lockdep-design.txt.
 
-config LOCKDEP
-	bool
-	depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
-	select STACKTRACE
-	select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE && !ARC && !SCORE && !X86
-	select KALLSYMS
-	select KALLSYMS_ALL
-
-config LOCKDEP_SMALL
-	bool
-
 config LOCK_STAT
 	bool "Lock usage statistics"
-	depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
+	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
 	select LOCKDEP
 	select DEBUG_SPINLOCK
 	select DEBUG_MUTEXES
@@ -1167,6 +1107,80 @@ config LOCK_STAT
 	 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
 	 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
 
+config DEBUG_RT_MUTEXES
+	bool "RT Mutex debugging, deadlock detection"
+	depends on DEBUG_KERNEL && RT_MUTEXES
+	help
+	 This allows rt mutex semantics violations and rt mutex related
+	 deadlocks (lockups) to be detected and reported automatically.
+
+config DEBUG_SPINLOCK
+	bool "Spinlock and rw-lock debugging: basic checks"
+	depends on DEBUG_KERNEL
+	select UNINLINE_SPIN_UNLOCK
+	help
+	  Say Y here and build SMP to catch missing spinlock initialization
+	  and certain other kinds of spinlock errors commonly made.  This is
+	  best used in conjunction with the NMI watchdog so that spinlock
+	  deadlocks are also debuggable.
+
+config DEBUG_MUTEXES
+	bool "Mutex debugging: basic checks"
+	depends on DEBUG_KERNEL
+	help
+	 This feature allows mutex semantics violations to be detected and
+	 reported.
+
+config DEBUG_WW_MUTEX_SLOWPATH
+	bool "Wait/wound mutex debugging: Slowpath testing"
+	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
+	select DEBUG_LOCK_ALLOC
+	select DEBUG_SPINLOCK
+	select DEBUG_MUTEXES
+	help
+	 This feature enables slowpath testing for w/w mutex users by
+	 injecting additional -EDEADLK wound/backoff cases. Together with
+	 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
+	 will test all possible w/w mutex interface abuse with the
+	 exception of simply not acquiring all the required locks.
+	 Note that this feature can introduce significant overhead, so
+	 it really should not be enabled in a production or distro kernel,
+	 even a debug kernel.  If you are a driver writer, enable it.  If
+	 you are a distro, do not.
+
+config DEBUG_RWSEMS
+	bool "RW Semaphore debugging: basic checks"
+	depends on DEBUG_KERNEL && RWSEM_SPIN_ON_OWNER
+	help
+	  This debugging feature allows mismatched rw semaphore locks and unlocks
+	  to be detected and reported.
+
+config DEBUG_LOCK_ALLOC
+	bool "Lock debugging: detect incorrect freeing of live locks"
+	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
+	select DEBUG_SPINLOCK
+	select DEBUG_MUTEXES
+	select DEBUG_RT_MUTEXES if RT_MUTEXES
+	select LOCKDEP
+	help
+	 This feature will check whether any held lock (spinlock, rwlock,
+	 mutex or rwsem) is incorrectly freed by the kernel, via any of the
+	 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
+	 vfree(), etc.), whether a live lock is incorrectly reinitialized via
+	 spin_lock_init()/mutex_init()/etc., or whether there is any lock
+	 held during task exit.
+
+config LOCKDEP
+	bool
+	depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
+	select STACKTRACE
+	select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE && !ARC && !SCORE && !X86
+	select KALLSYMS
+	select KALLSYMS_ALL
+
+config LOCKDEP_SMALL
+	bool
+
 config DEBUG_LOCKDEP
 	bool "Lock dependency engine debugging"
 	depends on DEBUG_KERNEL && LOCKDEP