[PATCH] lockdep: kconfig

Offer the following lock validation options: CONFIG_PROVE_LOCKING Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] lockdep: kconfig
Offer the following lock validation options: CONFIG_PROVE_LOCKING Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Ingo Molnar · Linus Torvalds
1 parent ef5d4707b9
Showing 1 changed file with 96 additions and 2 deletions Side-by-side Diff
lib/Kconfig.debug
@@ -134,7 +134,7 @@
 	  This option enables a rt-mutex tester.
  
 config DEBUG_SPINLOCK
-	bool "Spinlock debugging"
+	bool "Spinlock and rw-lock debugging: basic checks"
 	depends on DEBUG_KERNEL
 	help
 	  Say Y here and build SMP to catch missing spinlock initialization
  
@@ -142,8 +142,102 @@
 	  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_RWSEMS
+	bool "RW-sem debugging: basic checks"
+	depends on DEBUG_KERNEL
+	help
+	 This feature allows read-write semaphore semantics violations to
+	 be detected and reported.
+
+config DEBUG_LOCK_ALLOC
+	bool "Lock debugging: detect incorrect freeing of live locks"
+	depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
+	select DEBUG_SPINLOCK
+	select DEBUG_MUTEXES
+	select DEBUG_RWSEMS
+	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 PROVE_LOCKING
+	bool "Lock debugging: prove locking correctness"
+	depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
+	select LOCKDEP
+	select DEBUG_SPINLOCK
+	select DEBUG_MUTEXES
+	select DEBUG_RWSEMS
+	select DEBUG_LOCK_ALLOC
+	default n
+	help
+	 This feature enables the kernel to prove that all locking
+	 that occurs in the kernel runtime is mathematically
+	 correct: that under no circumstance could an arbitrary (and
+	 not yet triggered) combination of observed locking
+	 sequences (on an arbitrary number of CPUs, running an
+	 arbitrary number of tasks and interrupt contexts) cause a
+	 deadlock.
+
+	 In short, this feature enables the kernel to report locking
+	 related deadlocks before they actually occur.
+
+	 The proof does not depend on how hard and complex a
+	 deadlock scenario would be to trigger: how many
+	 participant CPUs, tasks and irq-contexts would be needed
+	 for it to trigger. The proof also does not depend on
+	 timing: if a race and a resulting deadlock is possible
+	 theoretically (no matter how unlikely the race scenario
+	 is), it will be proven so and will immediately be
+	 reported by the kernel (once the event is observed that
+	 makes the deadlock theoretically possible).
+
+	 If a deadlock is impossible (i.e. the locking rules, as
+	 observed by the kernel, are mathematically correct), the
+	 kernel reports nothing.
+
+	 NOTE: this feature can also be enabled for rwlocks, mutexes
+	 and rwsems - in which case all dependencies between these
+	 different locking variants are observed and mapped too, and
+	 the proof of observed correctness is also maintained for an
+	 arbitrary combination of these separate locking variants.
+
+	 For more details, see Documentation/lockdep-design.txt.
+
+config LOCKDEP
+	bool
+	depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
+	select STACKTRACE
+	select FRAME_POINTER
+	select KALLSYMS
+	select KALLSYMS_ALL
+
+config DEBUG_LOCKDEP
+	bool "Lock dependency engine debugging"
+	depends on LOCKDEP
+	help
+	  If you say Y here, the lock dependency engine will do
+	  additional runtime checks to debug itself, at the price
+	  of more runtime overhead.
+
+config TRACE_IRQFLAGS
+	bool
+	default y
+	depends on TRACE_IRQFLAGS_SUPPORT
+	depends on PROVE_LOCKING
+
 config DEBUG_SPINLOCK_SLEEP
-	bool "Sleep-inside-spinlock checking"
+	bool "Spinlock debugging: sleep-inside-spinlock checking"
 	depends on DEBUG_KERNEL
 	help
 	  If you say Y here, various routines which may sleep will become very
...	...	@@ -134,7 +134,7 @@
134	134	This option enables a rt-mutex tester.
135	135
136	136	config DEBUG_SPINLOCK
137		- bool "Spinlock debugging"
	137	+ bool "Spinlock and rw-lock debugging: basic checks"
138	138	depends on DEBUG_KERNEL
139	139	help
140	140	Say Y here and build SMP to catch missing spinlock initialization
141	141
...	...	@@ -142,8 +142,102 @@
142	142	best used in conjunction with the NMI watchdog so that spinlock
143	143	deadlocks are also debuggable.
144	144
	145	+config DEBUG_MUTEXES
	146	+ bool "Mutex debugging: basic checks"
	147	+ depends on DEBUG_KERNEL
	148	+ help
	149	+ This feature allows mutex semantics violations to be detected and
	150	+ reported.
	151	+
	152	+config DEBUG_RWSEMS
	153	+ bool "RW-sem debugging: basic checks"
	154	+ depends on DEBUG_KERNEL
	155	+ help
	156	+ This feature allows read-write semaphore semantics violations to
	157	+ be detected and reported.
	158	+
	159	+config DEBUG_LOCK_ALLOC
	160	+ bool "Lock debugging: detect incorrect freeing of live locks"
	161	+ depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
	162	+ select DEBUG_SPINLOCK
	163	+ select DEBUG_MUTEXES
	164	+ select DEBUG_RWSEMS
	165	+ select LOCKDEP
	166	+ help
	167	+ This feature will check whether any held lock (spinlock, rwlock,
	168	+ mutex or rwsem) is incorrectly freed by the kernel, via any of the
	169	+ memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
	170	+ vfree(), etc.), whether a live lock is incorrectly reinitialized via
	171	+ spin_lock_init()/mutex_init()/etc., or whether there is any lock
	172	+ held during task exit.
	173	+
	174	+config PROVE_LOCKING
	175	+ bool "Lock debugging: prove locking correctness"
	176	+ depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
	177	+ select LOCKDEP
	178	+ select DEBUG_SPINLOCK
	179	+ select DEBUG_MUTEXES
	180	+ select DEBUG_RWSEMS
	181	+ select DEBUG_LOCK_ALLOC
	182	+ default n
	183	+ help
	184	+ This feature enables the kernel to prove that all locking
	185	+ that occurs in the kernel runtime is mathematically
	186	+ correct: that under no circumstance could an arbitrary (and
	187	+ not yet triggered) combination of observed locking
	188	+ sequences (on an arbitrary number of CPUs, running an
	189	+ arbitrary number of tasks and interrupt contexts) cause a
	190	+ deadlock.
	191	+
	192	+ In short, this feature enables the kernel to report locking
	193	+ related deadlocks before they actually occur.
	194	+
	195	+ The proof does not depend on how hard and complex a
	196	+ deadlock scenario would be to trigger: how many
	197	+ participant CPUs, tasks and irq-contexts would be needed
	198	+ for it to trigger. The proof also does not depend on
	199	+ timing: if a race and a resulting deadlock is possible
	200	+ theoretically (no matter how unlikely the race scenario
	201	+ is), it will be proven so and will immediately be
	202	+ reported by the kernel (once the event is observed that
	203	+ makes the deadlock theoretically possible).
	204	+
	205	+ If a deadlock is impossible (i.e. the locking rules, as
	206	+ observed by the kernel, are mathematically correct), the
	207	+ kernel reports nothing.
	208	+
	209	+ NOTE: this feature can also be enabled for rwlocks, mutexes
	210	+ and rwsems - in which case all dependencies between these
	211	+ different locking variants are observed and mapped too, and
	212	+ the proof of observed correctness is also maintained for an
	213	+ arbitrary combination of these separate locking variants.
	214	+
	215	+ For more details, see Documentation/lockdep-design.txt.
	216	+
	217	+config LOCKDEP
	218	+ bool
	219	+ depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
	220	+ select STACKTRACE
	221	+ select FRAME_POINTER
	222	+ select KALLSYMS
	223	+ select KALLSYMS_ALL
	224	+
	225	+config DEBUG_LOCKDEP
	226	+ bool "Lock dependency engine debugging"
	227	+ depends on LOCKDEP
	228	+ help
	229	+ If you say Y here, the lock dependency engine will do
	230	+ additional runtime checks to debug itself, at the price
	231	+ of more runtime overhead.
	232	+
	233	+config TRACE_IRQFLAGS
	234	+ bool
	235	+ default y
	236	+ depends on TRACE_IRQFLAGS_SUPPORT
	237	+ depends on PROVE_LOCKING
	238	+
145	239	config DEBUG_SPINLOCK_SLEEP
146		- bool "Sleep-inside-spinlock checking"
	240	+ bool "Spinlock debugging: sleep-inside-spinlock checking"
147	241	depends on DEBUG_KERNEL
148	242	help
149	243	If you say Y here, various routines which may sleep will become very