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| author | Davidlohr Bueso <dave@stgolabs.net> | 2014-09-11 20:40:21 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-09-16 13:41:06 -0700 |
| commit | d36a7a0d5e8b5bff1671723d733eb61621b0cee4 (patch) | |
| tree | 17cbd1c2542a4b587890a593446757606a4a7834 /kernel | |
| parent | 1e6757a92189278c484799ea98fc69bdc528940e (diff) | |
| download | linux-d36a7a0d5e8b5bff1671723d733eb61621b0cee4.tar.gz linux-d36a7a0d5e8b5bff1671723d733eb61621b0cee4.tar.bz2 linux-d36a7a0d5e8b5bff1671723d733eb61621b0cee4.zip | |
torture: Address race in module cleanup
When performing module cleanups by calling torture_cleanup() the
'torture_type' string in nullified However, callers are not necessarily
done, and might still need to reference the variable. This impacts
both rcutorture and locktorture, causing printing things like:
[ 94.226618] (null)-torture: Stopping lock_torture_writer task
[ 94.226624] (null)-torture: Stopping lock_torture_stats task
Thus delay this operation until the very end of the cleanup process.
The consequence (which shouldn't matter for this kid of program) is,
of course, that we delay the window between rmmod and modprobing,
for instance in module_torture_begin().
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/locking/locktorture.c | 3 | ||||
| -rw-r--r-- | kernel/rcu/rcutorture.c | 3 | ||||
| -rw-r--r-- | kernel/torture.c | 16 |
3 files changed, 17 insertions, 5 deletions
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index de703a769c1d..988267cc92c1 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -361,7 +361,7 @@ static void lock_torture_cleanup(void) { int i; - if (torture_cleanup()) + if (torture_cleanup_begin()) return; if (writer_tasks) { @@ -384,6 +384,7 @@ static void lock_torture_cleanup(void) else lock_torture_print_module_parms(cur_ops, "End of test: SUCCESS"); + torture_cleanup_end(); } static int __init lock_torture_init(void) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 6d1509500d2b..04c4b5afb759 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1514,7 +1514,7 @@ rcu_torture_cleanup(void) int i; rcutorture_record_test_transition(); - if (torture_cleanup()) { + if (torture_cleanup_begin()) { if (cur_ops->cb_barrier != NULL) cur_ops->cb_barrier(); return; @@ -1566,6 +1566,7 @@ rcu_torture_cleanup(void) "End of test: RCU_HOTPLUG"); else rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS"); + torture_cleanup_end(); } #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD diff --git a/kernel/torture.c b/kernel/torture.c index ede8b25ec1ae..dd70993c266c 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -633,8 +633,13 @@ EXPORT_SYMBOL_GPL(torture_init_end); * * This must be called before the caller starts shutting down its own * kthreads. + * + * Both torture_cleanup_begin() and torture_cleanup_end() must be paired, + * in order to correctly perform the cleanup. They are separated because + * threads can still need to reference the torture_type type, thus nullify + * only after completing all other relevant calls. */ -bool torture_cleanup(void) +bool torture_cleanup_begin(void) { mutex_lock(&fullstop_mutex); if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { @@ -649,12 +654,17 @@ bool torture_cleanup(void) torture_shuffle_cleanup(); torture_stutter_cleanup(); torture_onoff_cleanup(); + return false; +} +EXPORT_SYMBOL_GPL(torture_cleanup_begin); + +void torture_cleanup_end(void) +{ mutex_lock(&fullstop_mutex); torture_type = NULL; mutex_unlock(&fullstop_mutex); - return false; } -EXPORT_SYMBOL_GPL(torture_cleanup); +EXPORT_SYMBOL_GPL(torture_cleanup_end); /* * Is it time for the current torture test to stop? |