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

Pull locking fixes from Ingo Molnar:
 "Misc fixes:

   - Fix a S390 boot hang that was caused by the lock-break logic.
     Remove lock-break to begin with, as review suggested it was
     unreasonably fragile and our confidence in its continued good
     health is lower than our confidence in its removal.

   - Remove the lockdep cross-release checking code for now, because of
     unresolved false positive warnings. This should make lockdep work
     well everywhere again.

   - Get rid of the final (and single) ACCESS_ONCE() straggler and
     remove the API from v4.15.

   - Fix a liblockdep build warning"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools/lib/lockdep: Add missing declaration of 'pr_cont()'
  checkpatch: Remove ACCESS_ONCE() warning
  compiler.h: Remove ACCESS_ONCE()
  tools/include: Remove ACCESS_ONCE()
  tools/perf: Convert ACCESS_ONCE() to READ_ONCE()
  locking/lockdep: Remove the cross-release locking checks
  locking/core: Remove break_lock field when CONFIG_GENERIC_LOCKBREAK=y
  locking/core: Fix deadlock during boot on systems with GENERIC_LOCKBREAK

1 files changed, 0 insertions, 33 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 947d3e2ed5c2..9d5b78aad4c5 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1099,8 +1099,6 @@ config PROVE_LOCKING
 	select DEBUG_MUTEXES
 	select DEBUG_RT_MUTEXES if RT_MUTEXES
 	select DEBUG_LOCK_ALLOC
-	select LOCKDEP_CROSSRELEASE
-	select LOCKDEP_COMPLETIONS
 	select TRACE_IRQFLAGS
 	default n
 	help
@@ -1170,37 +1168,6 @@ config LOCK_STAT
 	 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
 	 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
 
-config LOCKDEP_CROSSRELEASE
-	bool
-	help
-	 This makes lockdep work for crosslock which is a lock allowed to
-	 be released in a different context from the acquisition context.
-	 Normally a lock must be released in the context acquiring the lock.
-	 However, relexing this constraint helps synchronization primitives
-	 such as page locks or completions can use the lock correctness
-	 detector, lockdep.
-
-config LOCKDEP_COMPLETIONS
-	bool
-	help
-	 A deadlock caused by wait_for_completion() and complete() can be
-	 detected by lockdep using crossrelease feature.
-
-config BOOTPARAM_LOCKDEP_CROSSRELEASE_FULLSTACK
-	bool "Enable the boot parameter, crossrelease_fullstack"
-	depends on LOCKDEP_CROSSRELEASE
-	default n
-	help
-	 The lockdep "cross-release" feature needs to record stack traces
-	 (of calling functions) for all acquisitions, for eventual later
-	 use during analysis. By default only a single caller is recorded,
-	 because the unwind operation can be very expensive with deeper
-	 stack chains.
-
-	 However a boot parameter, crossrelease_fullstack, was
-	 introduced since sometimes deeper traces are required for full
-	 analysis. This option turns on the boot parameter.
-
 config DEBUG_LOCKDEP
 	bool "Lock dependency engine debugging"
 	depends on DEBUG_KERNEL && LOCKDEP