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authorWaiman Long <longman@redhat.com>2018-03-30 17:27:58 -0400
committerIngo Molnar <mingo@kernel.org>2018-03-31 07:30:50 +0200
commit5149cbac4235e12a34cf089592a8bd1c9fcfa467 (patch)
treedc8965899aaab98faf1c1f0b7319fd1af2dde616 /lib/Kconfig.debug
parent169310f71fc820fe153ec04c6a111e444a68d6d5 (diff)
downloadlwn-5149cbac4235e12a34cf089592a8bd1c9fcfa467.tar.gz
lwn-5149cbac4235e12a34cf089592a8bd1c9fcfa467.zip
locking/rwsem: Add DEBUG_RWSEMS to look for lock/unlock mismatches
For a rwsem, locking can either be exclusive or shared. The corresponding exclusive or shared unlock must be used. Otherwise, the protected data structures may get corrupted or the lock may be in an inconsistent state. In order to detect such anomaly, a new configuration option DEBUG_RWSEMS is added which can be enabled to look for such mismatches and print warnings that that happens. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1522445280-7767-2-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib/Kconfig.debug')
-rw-r--r--lib/Kconfig.debug8
1 files changed, 8 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 64155e310a9f..88650ab5cedb 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1075,6 +1075,13 @@ config DEBUG_WW_MUTEX_SLOWPATH
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 && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
@@ -1097,6 +1104,7 @@ config PROVE_LOCKING
select DEBUG_SPINLOCK
select DEBUG_MUTEXES
select DEBUG_RT_MUTEXES if RT_MUTEXES
+ select DEBUG_RWSEMS if RWSEM_SPIN_ON_OWNER
select DEBUG_LOCK_ALLOC
select TRACE_IRQFLAGS
default n