linux-toradex.git/kernel/locking/locktorture.c, branch v4.10-rc5

lcoking/locktorture: Simplify the torture_runnable computation

2016-04-28T08:57:51+00:00

This commit replaces an #ifdef with IS_ENABLED(), saving five lines.

Signed-off-by: Paul E. McKenney 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: corbet@lwn.net
Cc: dave@stgolabs.net
Cc: dhowells@redhat.com
Cc: linux-doc@vger.kernel.org
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1461691328-5429-4-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar

locking/locktorture: Fix NULL pointer dereference for cleanup paths

2016-04-13T06:52:23+00:00

It has been found that paths that invoke cleanups through
lock_torture_cleanup() can trigger NULL pointer dereferencing
bugs during the statistics printing phase. This is mainly
because we should not be calling into statistics before we are
sure things have been set up correctly.

Specifically, early checks (and the need for handling this in
the cleanup call) only include parameter checks and basic
statistics allocation. Once we start write/read kthreads
we then consider the test as started. As such, update the function
in question to check for cxt.lwsa writer stats, if not set,
we either have a bogus parameter or -ENOMEM situation and
therefore only need to deal with general torture calls.

Reported-and-tested-by: Kefeng Wang 
Signed-off-by: Davidlohr Bueso 
Signed-off-by: Paul E. McKenney 
Cc: Andrew Morton 
Cc: Davidlohr Bueso 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: bobby.prani@gmail.com
Cc: dhowells@redhat.com
Cc: dipankar@in.ibm.com
Cc: dvhart@linux.intel.com
Cc: edumazet@google.com
Cc: fweisbec@gmail.com
Cc: jiangshanlai@gmail.com
Cc: josh@joshtriplett.org
Cc: mathieu.desnoyers@efficios.com
Cc: oleg@redhat.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/1460476038-27060-2-git-send-email-paulmck@linux.vnet.ibm.com
[ Improved the changelog. ]
Signed-off-by: Ingo Molnar

locking/locktorture: Fix deboosting NULL pointer dereference

2016-04-13T06:52:23+00:00

For the case of rtmutex torturing we will randomly call into the
boost() handler, including upon module exiting when the tasks are
deboosted before stopping. In such cases the task may or may not have
already been boosted, and therefore the NULL being explicitly passed
can occur anywhere. Currently we only assume that the task will is
at a higher prio, and in consequence, dereference a NULL pointer.

This patch fixes the case of a rmmod locktorture exploding while
pounding on the rtmutex lock (partial trace):

 task: ffff88081026cf80 ti: ffff880816120000 task.ti: ffff880816120000
 RSP: 0018:ffff880816123eb0  EFLAGS: 00010206
 RAX: ffff88081026cf80 RBX: ffff880816bfa630 RCX: 0000000000160d1b
 RDX: 0000000000000000 RSI: 0000000000000202 RDI: 0000000000000000
 RBP: ffff88081026cf80 R08: 000000000000001f R09: ffff88017c20ca80
 R10: 0000000000000000 R11: 000000000048c316 R12: ffffffffa05d1840
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff88203f880000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000008 CR3: 0000000001c0a000 CR4: 00000000000406e0
 Stack:
  ffffffffa05d141d ffff880816bfa630 ffffffffa05d1922 ffff88081e70c2c0
  ffff880816bfa630 ffffffff81095fed 0000000000000000 ffffffff8107bf60
  ffff880816bfa630 ffffffff00000000 ffff880800000000 ffff880816123f08
 Call Trace:
  [] kthread+0xbd/0xe0
  [] ret_from_fork+0x3f/0x70

This patch ensures that if the random state pointer is not NULL and current
is not boosted, then do nothing.

 RIP: 0010:[]  [] torture_random+0x5/0x60 [torture]
  [] torture_rtmutex_boost+0x1d/0x90 [locktorture]
  [] lock_torture_writer+0xe2/0x170 [locktorture]

Signed-off-by: Davidlohr Bueso 
Signed-off-by: Paul E. McKenney 
Cc: Andrew Morton 
Cc: Davidlohr Bueso 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: bobby.prani@gmail.com
Cc: dhowells@redhat.com
Cc: dipankar@in.ibm.com
Cc: dvhart@linux.intel.com
Cc: edumazet@google.com
Cc: fweisbec@gmail.com
Cc: jiangshanlai@gmail.com
Cc: josh@joshtriplett.org
Cc: mathieu.desnoyers@efficios.com
Cc: oleg@redhat.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/1460476038-27060-1-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar

Merge branches 'doc.2015.10.06a', 'percpu-rwsem.2015.10.06a' and 'torture.2015.10.06a' into HEAD

2015-10-07T23:06:25+00:00

doc.2015.10.06a:  Documentation updates.
percpu-rwsem.2015.10.06a:  Optimization of per-CPU reader-writer semaphores.
torture.2015.10.06a:  Torture-test updates.

locktorture: Fix module unwind when bad torture_type specified

2015-10-06T18:28:44+00:00

The locktorture module has a list of torture types, and specifying
a type not on this list is supposed to cleanly fail the module load.
Unfortunately, the "fail" happens without the "cleanly".  This commit
therefore adds the needed clean-up after an incorrect torture_type.

Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

locktorture: Add torture tests for percpu_rwsem

2015-10-06T18:24:56+00:00

This commit adds percpu_rwsem tests based on the earlier rwsem tests.

Signed-off-by: Paul E. McKenney 
Cc: Oleg Nesterov 
Cc: Davidlohr Bueso 
Reviewed-by: Josh Triplett

locktorture: Support rtmutex torturing

2015-10-06T18:24:40+00:00

Real time mutexes is one of the few general primitives
that we do not have in locktorture. Address this -- a few
considerations:

o To spice things up, enable competing thread(s) to become
rt, such that we can stress different prio boosting paths
in the rtmutex code. Introduce a ->task_boost callback,
only used by rtmutex-torturer. Tasks will boost/deboost
around every 50k (arbitrarily) lock/unlock operations.

o Hold times are similar to what we have for other locks:
only occasionally having longer hold times (per ~200k ops).
So we roughly do two full rt boost+deboosting ops with
short hold times.

Signed-off-by: Davidlohr Bueso 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

locktorture: Change longdelay_us to longdelay_ms

2015-05-27T19:59:57+00:00

The locktorture long delays are in milliseconds rather than microseconds,
so this commit changes the name of the corresponding variable from
longdelay_us to longdelay_ms.

Reported-by: Ben Goodwyn 
Signed-off-by: Paul E. McKenney 
Cc: Davidlohr Bueso 
Reviewed-by: Josh Triplett

locktorture: fix deadlock in 'rw_lock_irq' type

2015-05-27T19:59:56+00:00

torture_rwlock_read_unlock_irq() must use read_unlock_irqrestore()
instead of write_unlock_irqrestore().

Use read_unlock_irqrestore() instead of write_unlock_irqrestore().

Signed-off-by: Alexey Kodanev 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

locktorture: Cleanup header usage

2014-09-30T07:10:02+00:00

Remove some unnecessary ones and explicitly include rwsem.h

Signed-off-by: Davidlohr Bueso 
Signed-off-by: Paul E. McKenney