[PATCH RT 00/10] Linux 4.4.50-rt63-rc1

[PATCH RT 00/10] Linux 4.4.50-rt63-rc1

[Steven Rostedt]

Dear RT Folks,

This is the RT stable review cycle of patch 4.4.50-rt63-rc1.

Please scream at me if I messed something up. Please test the patches too.

The -rc release will be uploaded to kernel.org and will be deleted when
the final release is out. This is just a review release (or release candidate).

The pre-releases will not be pushed to the git repository, only the
final release is.

If all goes well, this patch will be converted to the next main release
on 3/10/2017.

**** NOTE ****

Julia Cartwright has kindly offered to take over maintaining v4.1-rt.
She will be sending out and maintaining patches and the v4.1-rt git tree.

Thank you Julia!

**** **** ****
 
Enjoy,

-- Steve


To build 4.4.50-rt63-rc1 directly, the following patches should be applied:

  http://www.kernel.org/pub/linux/kernel/v4.x/linux-4.4.tar.xz

  http://www.kernel.org/pub/linux/kernel/v4.x/patch-4.4.50.xz

  http://www.kernel.org/pub/linux/kernel/projects/rt/4.4/patch-4.4.50-rt63-rc1.patch.xz

You can also build from 4.4.50-rt62 by applying the incremental patch:

http://www.kernel.org/pub/linux/kernel/projects/rt/4.4/incr/patch-4.4.50-rt62-rt63-rc1.patch.xz


Changes from 4.4.50-rt62:

---


Dan Murphy (1):
      lockdep: Fix compilation error for !CONFIG_MODULES and !CONFIG_SMP

John Ogness (1):
      x86/mm/cpa: avoid wbinvd() for PREEMPT

Julia Cartwright (1):
      pinctrl: qcom: Use raw spinlock variants

Mike Galbraith (1):
      cpuset: Convert callback_lock to raw_spinlock_t

Sebastian Andrzej Siewior (4):
      radix-tree: use local locks
      rt: Drop mutex_disable() on !DEBUG configs and the GPL suffix from export symbol
      sched/rt: Add a missing rescheduling point
      rt: Drop the removal of _GPL from rt_mutex_destroy()'s EXPORT_SYMBOL

Steven Rostedt (VMware) (1):
      Linux 4.4.50-rt63-rc1

Thomas Gleixner (1):
      lockdep: Handle statically initialized PER_CPU locks proper

----
 arch/x86/mm/pageattr.c             |  8 +++++
 drivers/pinctrl/qcom/pinctrl-msm.c | 48 +++++++++++++--------------
 include/linux/module.h             |  6 ++++
 include/linux/mutex_rt.h           |  5 +++
 include/linux/percpu.h             |  1 +
 include/linux/radix-tree.h         | 12 ++-----
 kernel/cpuset.c                    | 66 +++++++++++++++++++-------------------
 kernel/locking/lockdep.c           | 33 +++++++++++++------
 kernel/module.c                    | 36 ++++++++++++++-------
 kernel/sched/deadline.c            |  3 +-
 kernel/sched/rt.c                  |  3 +-
 lib/radix-tree.c                   | 23 +++++++------
 localversion-rt                    |  2 +-
 mm/percpu.c                        | 37 +++++++++++++--------
 14 files changed, 166 insertions(+), 117 deletions(-)

[PATCH RT 01/10] cpuset: Convert callback_lock to raw_spinlock_t

[Steven Rostedt]

[-- Attachment #1: 0001-cpuset-Convert-callback_lock-to-raw_spinlock_t.patch --]
[-- Type: text/plain, Size: 9922 bytes --]

4.4.50-rt63-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Mike Galbraith <efault@gmx.de>

The two commits below add up to a cpuset might_sleep() splat for RT:

8447a0fee974 cpuset: convert callback_mutex to a spinlock
344736f29b35 cpuset: simplify cpuset_node_allowed API

BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:995
in_atomic(): 0, irqs_disabled(): 1, pid: 11718, name: cset
CPU: 135 PID: 11718 Comm: cset Tainted: G            E   4.10.0-rt1-rt #4
Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS BRHSXSD1.86B.0056.R01.1409242327 09/24/2014
Call Trace:
 ? dump_stack+0x5c/0x81
 ? ___might_sleep+0xf4/0x170
 ? rt_spin_lock+0x1c/0x50
 ? __cpuset_node_allowed+0x66/0xc0
 ? ___slab_alloc+0x390/0x570 <disables IRQs>
 ? anon_vma_fork+0x8f/0x140
 ? copy_page_range+0x6cf/0xb00
 ? anon_vma_fork+0x8f/0x140
 ? __slab_alloc.isra.74+0x5a/0x81
 ? anon_vma_fork+0x8f/0x140
 ? kmem_cache_alloc+0x1b5/0x1f0
 ? anon_vma_fork+0x8f/0x140
 ? copy_process.part.35+0x1670/0x1ee0
 ? _do_fork+0xdd/0x3f0
 ? _do_fork+0xdd/0x3f0
 ? do_syscall_64+0x61/0x170
 ? entry_SYSCALL64_slow_path+0x25/0x25

The later ensured that a NUMA box WILL take callback_lock in atomic
context by removing the allocator and reclaim path __GFP_HARDWALL
usage which prevented such contexts from taking callback_mutex.

One option would be to reinstate __GFP_HARDWALL protections for
RT, however, as the 8447a0fee974 changelog states:

The callback_mutex is only used to synchronize reads/updates of cpusets'
flags and cpu/node masks. These operations should always proceed fast so
there's no reason why we can't use a spinlock instead of the mutex.

Cc: stable-rt@vger.kernel.org
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/cpuset.c | 66 ++++++++++++++++++++++++++++-----------------------------
 1 file changed, 33 insertions(+), 33 deletions(-)

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index b271353d5202..dd7b87b7f618 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -283,7 +283,7 @@ static struct cpuset top_cpuset = {
  */
 
 static DEFINE_MUTEX(cpuset_mutex);
-static DEFINE_SPINLOCK(callback_lock);
+static DEFINE_RAW_SPINLOCK(callback_lock);
 
 static struct workqueue_struct *cpuset_migrate_mm_wq;
 
@@ -906,9 +906,9 @@ static void update_cpumasks_hier(struct cpuset *cs, struct cpumask *new_cpus)
 			continue;
 		rcu_read_unlock();
 
-		spin_lock_irq(&callback_lock);
+		raw_spin_lock_irq(&callback_lock);
 		cpumask_copy(cp->effective_cpus, new_cpus);
-		spin_unlock_irq(&callback_lock);
+		raw_spin_unlock_irq(&callback_lock);
 
 		WARN_ON(!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
 			!cpumask_equal(cp->cpus_allowed, cp->effective_cpus));
@@ -973,9 +973,9 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
 	if (retval < 0)
 		return retval;
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed);
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 
 	/* use trialcs->cpus_allowed as a temp variable */
 	update_cpumasks_hier(cs, trialcs->cpus_allowed);
@@ -1184,9 +1184,9 @@ static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems)
 			continue;
 		rcu_read_unlock();
 
-		spin_lock_irq(&callback_lock);
+		raw_spin_lock_irq(&callback_lock);
 		cp->effective_mems = *new_mems;
-		spin_unlock_irq(&callback_lock);
+		raw_spin_unlock_irq(&callback_lock);
 
 		WARN_ON(!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
 			!nodes_equal(cp->mems_allowed, cp->effective_mems));
@@ -1254,9 +1254,9 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
 	if (retval < 0)
 		goto done;
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	cs->mems_allowed = trialcs->mems_allowed;
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 
 	/* use trialcs->mems_allowed as a temp variable */
 	update_nodemasks_hier(cs, &trialcs->mems_allowed);
@@ -1347,9 +1347,9 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
 	spread_flag_changed = ((is_spread_slab(cs) != is_spread_slab(trialcs))
 			|| (is_spread_page(cs) != is_spread_page(trialcs)));
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	cs->flags = trialcs->flags;
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 
 	if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed)
 		rebuild_sched_domains_locked();
@@ -1761,7 +1761,7 @@ static int cpuset_common_seq_show(struct seq_file *sf, void *v)
 	cpuset_filetype_t type = seq_cft(sf)->private;
 	int ret = 0;
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 
 	switch (type) {
 	case FILE_CPULIST:
@@ -1780,7 +1780,7 @@ static int cpuset_common_seq_show(struct seq_file *sf, void *v)
 		ret = -EINVAL;
 	}
 
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 	return ret;
 }
 
@@ -1994,12 +1994,12 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
 
 	cpuset_inc();
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys)) {
 		cpumask_copy(cs->effective_cpus, parent->effective_cpus);
 		cs->effective_mems = parent->effective_mems;
 	}
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 
 	if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags))
 		goto out_unlock;
@@ -2026,12 +2026,12 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
 	}
 	rcu_read_unlock();
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	cs->mems_allowed = parent->mems_allowed;
 	cs->effective_mems = parent->mems_allowed;
 	cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);
 	cpumask_copy(cs->effective_cpus, parent->cpus_allowed);
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 out_unlock:
 	mutex_unlock(&cpuset_mutex);
 	return 0;
@@ -2070,7 +2070,7 @@ static void cpuset_css_free(struct cgroup_subsys_state *css)
 static void cpuset_bind(struct cgroup_subsys_state *root_css)
 {
 	mutex_lock(&cpuset_mutex);
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 
 	if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys)) {
 		cpumask_copy(top_cpuset.cpus_allowed, cpu_possible_mask);
@@ -2081,7 +2081,7 @@ static void cpuset_bind(struct cgroup_subsys_state *root_css)
 		top_cpuset.mems_allowed = top_cpuset.effective_mems;
 	}
 
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 	mutex_unlock(&cpuset_mutex);
 }
 
@@ -2182,12 +2182,12 @@ hotplug_update_tasks_legacy(struct cpuset *cs,
 {
 	bool is_empty;
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	cpumask_copy(cs->cpus_allowed, new_cpus);
 	cpumask_copy(cs->effective_cpus, new_cpus);
 	cs->mems_allowed = *new_mems;
 	cs->effective_mems = *new_mems;
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 
 	/*
 	 * Don't call update_tasks_cpumask() if the cpuset becomes empty,
@@ -2224,10 +2224,10 @@ hotplug_update_tasks(struct cpuset *cs,
 	if (nodes_empty(*new_mems))
 		*new_mems = parent_cs(cs)->effective_mems;
 
-	spin_lock_irq(&callback_lock);
+	raw_spin_lock_irq(&callback_lock);
 	cpumask_copy(cs->effective_cpus, new_cpus);
 	cs->effective_mems = *new_mems;
-	spin_unlock_irq(&callback_lock);
+	raw_spin_unlock_irq(&callback_lock);
 
 	if (cpus_updated)
 		update_tasks_cpumask(cs);
@@ -2313,21 +2313,21 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
 
 	/* synchronize cpus_allowed to cpu_active_mask */
 	if (cpus_updated) {
-		spin_lock_irq(&callback_lock);
+		raw_spin_lock_irq(&callback_lock);
 		if (!on_dfl)
 			cpumask_copy(top_cpuset.cpus_allowed, &new_cpus);
 		cpumask_copy(top_cpuset.effective_cpus, &new_cpus);
-		spin_unlock_irq(&callback_lock);
+		raw_spin_unlock_irq(&callback_lock);
 		/* we don't mess with cpumasks of tasks in top_cpuset */
 	}
 
 	/* synchronize mems_allowed to N_MEMORY */
 	if (mems_updated) {
-		spin_lock_irq(&callback_lock);
+		raw_spin_lock_irq(&callback_lock);
 		if (!on_dfl)
 			top_cpuset.mems_allowed = new_mems;
 		top_cpuset.effective_mems = new_mems;
-		spin_unlock_irq(&callback_lock);
+		raw_spin_unlock_irq(&callback_lock);
 		update_tasks_nodemask(&top_cpuset);
 	}
 
@@ -2425,11 +2425,11 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&callback_lock, flags);
+	raw_spin_lock_irqsave(&callback_lock, flags);
 	rcu_read_lock();
 	guarantee_online_cpus(task_cs(tsk), pmask);
 	rcu_read_unlock();
-	spin_unlock_irqrestore(&callback_lock, flags);
+	raw_spin_unlock_irqrestore(&callback_lock, flags);
 }
 
 void cpuset_cpus_allowed_fallback(struct task_struct *tsk)
@@ -2477,11 +2477,11 @@ nodemask_t cpuset_mems_allowed(struct task_struct *tsk)
 	nodemask_t mask;
 	unsigned long flags;
 
-	spin_lock_irqsave(&callback_lock, flags);
+	raw_spin_lock_irqsave(&callback_lock, flags);
 	rcu_read_lock();
 	guarantee_online_mems(task_cs(tsk), &mask);
 	rcu_read_unlock();
-	spin_unlock_irqrestore(&callback_lock, flags);
+	raw_spin_unlock_irqrestore(&callback_lock, flags);
 
 	return mask;
 }
@@ -2573,14 +2573,14 @@ int __cpuset_node_allowed(int node, gfp_t gfp_mask)
 		return 1;
 
 	/* Not hardwall and node outside mems_allowed: scan up cpusets */
-	spin_lock_irqsave(&callback_lock, flags);
+	raw_spin_lock_irqsave(&callback_lock, flags);
 
 	rcu_read_lock();
 	cs = nearest_hardwall_ancestor(task_cs(current));
 	allowed = node_isset(node, cs->mems_allowed);
 	rcu_read_unlock();
 
-	spin_unlock_irqrestore(&callback_lock, flags);
+	raw_spin_unlock_irqrestore(&callback_lock, flags);
 	return allowed;
 }
 
-- 
2.10.2

[PATCH RT 02/10] radix-tree: use local locks

[Steven Rostedt]

[-- Attachment #1: 0002-radix-tree-use-local-locks.patch --]
[-- Type: text/plain, Size: 4773 bytes --]

4.4.50-rt63-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

The preload functionality uses per-CPU variables and preempt-disable to
ensure that it does not switch CPUs during its usage. This patch adds
local_locks() instead preempt_disable() for the same purpose and to
remain preemptible on -RT.

Cc: stable-rt@vger.kernel.org
Reported-and-debugged-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/radix-tree.h | 12 ++----------
 lib/radix-tree.c           | 23 ++++++++++++++---------
 2 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index 8ddbd6e15a3c..327dddaf4c8f 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -277,13 +277,10 @@ radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
 unsigned int radix_tree_gang_lookup_slot(struct radix_tree_root *root,
 			void ***results, unsigned long *indices,
 			unsigned long first_index, unsigned int max_items);
-#ifndef CONFIG_PREEMPT_RT_FULL
 int radix_tree_preload(gfp_t gfp_mask);
 int radix_tree_maybe_preload(gfp_t gfp_mask);
-#else
-static inline int radix_tree_preload(gfp_t gm) { return 0; }
-static inline int radix_tree_maybe_preload(gfp_t gfp_mask) { return 0; }
-#endif
+void radix_tree_preload_end(void);
+
 void radix_tree_init(void);
 void *radix_tree_tag_set(struct radix_tree_root *root,
 			unsigned long index, unsigned int tag);
@@ -306,11 +303,6 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
 int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag);
 unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item);
 
-static inline void radix_tree_preload_end(void)
-{
-	preempt_enable_nort();
-}
-
 /**
  * struct radix_tree_iter - radix tree iterator state
  *
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index f27e0bcb74f7..44bf36a396a9 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -34,7 +34,7 @@
 #include <linux/bitops.h>
 #include <linux/rcupdate.h>
 #include <linux/preempt.h>		/* in_interrupt() */
-
+#include <linux/locallock.h>
 
 /*
  * The height_to_maxindex array needs to be one deeper than the maximum
@@ -69,6 +69,7 @@ struct radix_tree_preload {
 	struct radix_tree_node *nodes;
 };
 static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, };
+static DEFINE_LOCAL_IRQ_LOCK(radix_tree_preloads_lock);
 
 static inline void *ptr_to_indirect(void *ptr)
 {
@@ -196,14 +197,14 @@ radix_tree_node_alloc(struct radix_tree_root *root)
 		 * succeed in getting a node here (and never reach
 		 * kmem_cache_alloc)
 		 */
-		rtp = &get_cpu_var(radix_tree_preloads);
+		rtp = &get_locked_var(radix_tree_preloads_lock, radix_tree_preloads);
 		if (rtp->nr) {
 			ret = rtp->nodes;
 			rtp->nodes = ret->private_data;
 			ret->private_data = NULL;
 			rtp->nr--;
 		}
-		put_cpu_var(radix_tree_preloads);
+		put_locked_var(radix_tree_preloads_lock, radix_tree_preloads);
 		/*
 		 * Update the allocation stack trace as this is more useful
 		 * for debugging.
@@ -243,7 +244,6 @@ radix_tree_node_free(struct radix_tree_node *node)
 	call_rcu(&node->rcu_head, radix_tree_node_rcu_free);
 }
 
-#ifndef CONFIG_PREEMPT_RT_FULL
 /*
  * Load up this CPU's radix_tree_node buffer with sufficient objects to
  * ensure that the addition of a single element in the tree cannot fail.  On
@@ -259,14 +259,14 @@ static int __radix_tree_preload(gfp_t gfp_mask)
 	struct radix_tree_node *node;
 	int ret = -ENOMEM;
 
-	preempt_disable();
+	local_lock(radix_tree_preloads_lock);
 	rtp = this_cpu_ptr(&radix_tree_preloads);
 	while (rtp->nr < RADIX_TREE_PRELOAD_SIZE) {
-		preempt_enable();
+		local_unlock(radix_tree_preloads_lock);
 		node = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask);
 		if (node == NULL)
 			goto out;
-		preempt_disable();
+		local_lock(radix_tree_preloads_lock);
 		rtp = this_cpu_ptr(&radix_tree_preloads);
 		if (rtp->nr < RADIX_TREE_PRELOAD_SIZE) {
 			node->private_data = rtp->nodes;
@@ -308,11 +308,16 @@ int radix_tree_maybe_preload(gfp_t gfp_mask)
 	if (gfpflags_allow_blocking(gfp_mask))
 		return __radix_tree_preload(gfp_mask);
 	/* Preloading doesn't help anything with this gfp mask, skip it */
-	preempt_disable();
+	local_lock(radix_tree_preloads_lock);
 	return 0;
 }
 EXPORT_SYMBOL(radix_tree_maybe_preload);
-#endif
+
+void radix_tree_preload_end(void)
+{
+	local_unlock(radix_tree_preloads_lock);
+}
+EXPORT_SYMBOL(radix_tree_preload_end);
 
 /*
  *	Return the maximum key which can be store into a
-- 
2.10.2

[PATCH RT 03/10] pinctrl: qcom: Use raw spinlock variants

[Steven Rostedt]

[-- Attachment #1: 0003-pinctrl-qcom-Use-raw-spinlock-variants.patch --]
[-- Type: text/plain, Size: 8452 bytes --]

4.4.50-rt63-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Julia Cartwright <julia@ni.com>

The MSM pinctrl driver currently implements an irq_chip for handling
GPIO interrupts; due to how irq_chip handling is done, it's necessary
for the irq_chip methods to be invoked from hardirq context, even on a
a real-time kernel.  Because the spinlock_t type becomes a "sleeping"
spinlock w/ RT kernels, it is not suitable to be used with irq_chips.

A quick audit of the operations under the lock reveal that they do only
minimal, bounded work, and are therefore safe to do under a raw
spinlock.

On real-time kernels, this fixes an OOPs which looks like the following,
as reported by Brian Wrenn:

    kernel BUG at kernel/locking/rtmutex.c:1014!
    Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
    Modules linked in: spidev_irq(O) smsc75xx wcn36xx [last unloaded: spidev]
    CPU: 0 PID: 1163 Comm: irq/144-mmc0 Tainted: G        W  O    4.4.9-linaro-lt-qcom #1
    PC is at rt_spin_lock_slowlock+0x80/0x2d8
    LR is at rt_spin_lock_slowlock+0x68/0x2d8
    [..]
  Call trace:
    rt_spin_lock_slowlock
    rt_spin_lock
    msm_gpio_irq_ack
    handle_edge_irq
    generic_handle_irq
    msm_gpio_irq_handler
    generic_handle_irq
    __handle_domain_irq
    gic_handle_irq

Cc: stable-rt@vger.kernel.org
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Reported-by: Brian Wrenn <dcbrianw@gmail.com>
Tested-by: Brian Wrenn <dcbrianw@gmail.com>
Signed-off-by: Julia Cartwright <julia@ni.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 drivers/pinctrl/qcom/pinctrl-msm.c | 48 +++++++++++++++++++-------------------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
index 146264a41ec8..81fd38894eaf 100644
--- a/drivers/pinctrl/qcom/pinctrl-msm.c
+++ b/drivers/pinctrl/qcom/pinctrl-msm.c
@@ -60,7 +60,7 @@ struct msm_pinctrl {
 	struct notifier_block restart_nb;
 	int irq;
 
-	spinlock_t lock;
+	raw_spinlock_t lock;
 
 	DECLARE_BITMAP(dual_edge_irqs, MAX_NR_GPIO);
 	DECLARE_BITMAP(enabled_irqs, MAX_NR_GPIO);
@@ -156,14 +156,14 @@ static int msm_pinmux_set_mux(struct pinctrl_dev *pctldev,
 	if (WARN_ON(i == g->nfuncs))
 		return -EINVAL;
 
-	spin_lock_irqsave(&pctrl->lock, flags);
+	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
 	val = readl(pctrl->regs + g->ctl_reg);
 	val &= ~(0x7 << g->mux_bit);
 	val |= i << g->mux_bit;
 	writel(val, pctrl->regs + g->ctl_reg);
 
-	spin_unlock_irqrestore(&pctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 
 	return 0;
 }
@@ -326,14 +326,14 @@ static int msm_config_group_set(struct pinctrl_dev *pctldev,
 			break;
 		case PIN_CONFIG_OUTPUT:
 			/* set output value */
-			spin_lock_irqsave(&pctrl->lock, flags);
+			raw_spin_lock_irqsave(&pctrl->lock, flags);
 			val = readl(pctrl->regs + g->io_reg);
 			if (arg)
 				val |= BIT(g->out_bit);
 			else
 				val &= ~BIT(g->out_bit);
 			writel(val, pctrl->regs + g->io_reg);
-			spin_unlock_irqrestore(&pctrl->lock, flags);
+			raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 
 			/* enable output */
 			arg = 1;
@@ -354,12 +354,12 @@ static int msm_config_group_set(struct pinctrl_dev *pctldev,
 			return -EINVAL;
 		}
 
-		spin_lock_irqsave(&pctrl->lock, flags);
+		raw_spin_lock_irqsave(&pctrl->lock, flags);
 		val = readl(pctrl->regs + g->ctl_reg);
 		val &= ~(mask << bit);
 		val |= arg << bit;
 		writel(val, pctrl->regs + g->ctl_reg);
-		spin_unlock_irqrestore(&pctrl->lock, flags);
+		raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 	}
 
 	return 0;
@@ -387,13 +387,13 @@ static int msm_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 
 	g = &pctrl->soc->groups[offset];
 
-	spin_lock_irqsave(&pctrl->lock, flags);
+	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
 	val = readl(pctrl->regs + g->ctl_reg);
 	val &= ~BIT(g->oe_bit);
 	writel(val, pctrl->regs + g->ctl_reg);
 
-	spin_unlock_irqrestore(&pctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 
 	return 0;
 }
@@ -407,7 +407,7 @@ static int msm_gpio_direction_output(struct gpio_chip *chip, unsigned offset, in
 
 	g = &pctrl->soc->groups[offset];
 
-	spin_lock_irqsave(&pctrl->lock, flags);
+	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
 	val = readl(pctrl->regs + g->io_reg);
 	if (value)
@@ -420,7 +420,7 @@ static int msm_gpio_direction_output(struct gpio_chip *chip, unsigned offset, in
 	val |= BIT(g->oe_bit);
 	writel(val, pctrl->regs + g->ctl_reg);
 
-	spin_unlock_irqrestore(&pctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 
 	return 0;
 }
@@ -446,7 +446,7 @@ static void msm_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 
 	g = &pctrl->soc->groups[offset];
 
-	spin_lock_irqsave(&pctrl->lock, flags);
+	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
 	val = readl(pctrl->regs + g->io_reg);
 	if (value)
@@ -455,7 +455,7 @@ static void msm_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 		val &= ~BIT(g->out_bit);
 	writel(val, pctrl->regs + g->io_reg);
 
-	spin_unlock_irqrestore(&pctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 }
 
 #ifdef CONFIG_DEBUG_FS
@@ -574,7 +574,7 @@ static void msm_gpio_irq_mask(struct irq_data *d)
 
 	g = &pctrl->soc->groups[d->hwirq];
 
-	spin_lock_irqsave(&pctrl->lock, flags);
+	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
 	val = readl(pctrl->regs + g->intr_cfg_reg);
 	val &= ~BIT(g->intr_enable_bit);
@@ -582,7 +582,7 @@ static void msm_gpio_irq_mask(struct irq_data *d)
 
 	clear_bit(d->hwirq, pctrl->enabled_irqs);
 
-	spin_unlock_irqrestore(&pctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 }
 
 static void msm_gpio_irq_unmask(struct irq_data *d)
@@ -595,7 +595,7 @@ static void msm_gpio_irq_unmask(struct irq_data *d)
 
 	g = &pctrl->soc->groups[d->hwirq];
 
-	spin_lock_irqsave(&pctrl->lock, flags);
+	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
 	val = readl(pctrl->regs + g->intr_status_reg);
 	val &= ~BIT(g->intr_status_bit);
@@ -607,7 +607,7 @@ static void msm_gpio_irq_unmask(struct irq_data *d)
 
 	set_bit(d->hwirq, pctrl->enabled_irqs);
 
-	spin_unlock_irqrestore(&pctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 }
 
 static void msm_gpio_irq_ack(struct irq_data *d)
@@ -620,7 +620,7 @@ static void msm_gpio_irq_ack(struct irq_data *d)
 
 	g = &pctrl->soc->groups[d->hwirq];
 
-	spin_lock_irqsave(&pctrl->lock, flags);
+	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
 	val = readl(pctrl->regs + g->intr_status_reg);
 	if (g->intr_ack_high)
@@ -632,7 +632,7 @@ static void msm_gpio_irq_ack(struct irq_data *d)
 	if (test_bit(d->hwirq, pctrl->dual_edge_irqs))
 		msm_gpio_update_dual_edge_pos(pctrl, g, d);
 
-	spin_unlock_irqrestore(&pctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 }
 
 static int msm_gpio_irq_set_type(struct irq_data *d, unsigned int type)
@@ -645,7 +645,7 @@ static int msm_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 
 	g = &pctrl->soc->groups[d->hwirq];
 
-	spin_lock_irqsave(&pctrl->lock, flags);
+	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
 	/*
 	 * For hw without possibility of detecting both edges
@@ -719,7 +719,7 @@ static int msm_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 	if (test_bit(d->hwirq, pctrl->dual_edge_irqs))
 		msm_gpio_update_dual_edge_pos(pctrl, g, d);
 
-	spin_unlock_irqrestore(&pctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 
 	if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
 		irq_set_handler_locked(d, handle_level_irq);
@@ -735,11 +735,11 @@ static int msm_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
 	struct msm_pinctrl *pctrl = to_msm_pinctrl(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&pctrl->lock, flags);
+	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
 	irq_set_irq_wake(pctrl->irq, on);
 
-	spin_unlock_irqrestore(&pctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 
 	return 0;
 }
@@ -885,7 +885,7 @@ int msm_pinctrl_probe(struct platform_device *pdev,
 	pctrl->soc = soc_data;
 	pctrl->chip = msm_gpio_template;
 
-	spin_lock_init(&pctrl->lock);
+	raw_spin_lock_init(&pctrl->lock);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	pctrl->regs = devm_ioremap_resource(&pdev->dev, res);
-- 
2.10.2

[PATCH RT 04/10] x86/mm/cpa: avoid wbinvd() for PREEMPT

[Steven Rostedt]

[-- Attachment #1: 0004-x86-mm-cpa-avoid-wbinvd-for-PREEMPT.patch --]
[-- Type: text/plain, Size: 1521 bytes --]

4.4.50-rt63-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: John Ogness <john.ogness@linutronix.de>

Although wbinvd() is faster than flushing many individual pages, it
blocks the memory bus for "long" periods of time (>100us), thus
directly causing unusually large latencies on all CPUs, regardless
of any CPU isolation features that may be active.

For 1024 pages, flushing those pages individually can take up to
2200us, but the task remains fully preemptible during that time.

Cc: stable-rt@vger.kernel.org
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 arch/x86/mm/pageattr.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index b599a780a5a9..2e85c4117daf 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -208,7 +208,15 @@ static void cpa_flush_array(unsigned long *start, int numpages, int cache,
 			    int in_flags, struct page **pages)
 {
 	unsigned int i, level;
+#ifdef CONFIG_PREEMPT
+	/*
+	 * Avoid wbinvd() because it causes latencies on all CPUs,
+	 * regardless of any CPU isolation that may be in effect.
+	 */
+	unsigned long do_wbinvd = 0;
+#else
 	unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */
+#endif
 
 	BUG_ON(irqs_disabled());
 
-- 
2.10.2

[PATCH RT 05/10] rt: Drop mutex_disable() on !DEBUG configs and the GPL suffix from export symbol

[Steven Rostedt]

[-- Attachment #1: 0005-rt-Drop-mutex_disable-on-DEBUG-configs-and-the-GPL-s.patch --]
[-- Type: text/plain, Size: 2032 bytes --]

4.4.50-rt63-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

Alex Goins reported that mutex_destroy() on RT will force a GPL only symbol
which won't link and therefore fail on a non-GPL kernel module.
This does not happen on !RT and is a regression on RT which we would like to
avoid.
I try here the easy thing and to not use rt_mutex_destroy() if
CONFIG_DEBUG_MUTEXES is not enabled. This will still break for the DEBUG
configs so instead of adding a wrapper around rt_mutex_destroy() (which we have
for rt_mutex_lock() for instance) I am simply dropping the GPL part from the
export.

Reported-by: Alex Goins <agoins@nvidia.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/mutex_rt.h | 5 +++++
 kernel/locking/rtmutex.c | 3 +--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/linux/mutex_rt.h b/include/linux/mutex_rt.h
index c38a44b14da5..e0284edec655 100644
--- a/include/linux/mutex_rt.h
+++ b/include/linux/mutex_rt.h
@@ -43,7 +43,12 @@ extern void __lockfunc _mutex_unlock(struct mutex *lock);
 #define mutex_lock_killable(l)		_mutex_lock_killable(l)
 #define mutex_trylock(l)		_mutex_trylock(l)
 #define mutex_unlock(l)			_mutex_unlock(l)
+
+#ifdef CONFIG_DEBUG_MUTEXES
 #define mutex_destroy(l)		rt_mutex_destroy(&(l)->lock)
+#else
+static inline void mutex_destroy(struct mutex *lock) {}
+#endif
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 # define mutex_lock_nested(l, s)	_mutex_lock_nested(l, s)
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 0e9a6260441d..56f5f1a9baf8 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -2216,8 +2216,7 @@ void rt_mutex_destroy(struct rt_mutex *lock)
 	lock->magic = NULL;
 #endif
 }
-
-EXPORT_SYMBOL_GPL(rt_mutex_destroy);
+EXPORT_SYMBOL(rt_mutex_destroy);
 
 /**
  * __rt_mutex_init - initialize the rt lock
-- 
2.10.2

[PATCH RT 06/10] sched/rt: Add a missing rescheduling point

[Steven Rostedt]

[-- Attachment #1: 0006-sched-rt-Add-a-missing-rescheduling-point.patch --]
[-- Type: text/plain, Size: 2811 bytes --]

4.4.50-rt63-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

Since the change in commit:

  fd7a4bed1835 ("sched, rt: Convert switched_{from, to}_rt() / prio_changed_rt() to balance callbacks")

... we don't reschedule a task under certain circumstances:

Lets say task-A, SCHED_OTHER, is running on CPU0 (and it may run only on
CPU0) and holds a PI lock. This task is removed from the CPU because it
used up its time slice and another SCHED_OTHER task is running. Task-B on
CPU1 runs at RT priority and asks for the lock owned by task-A. This
results in a priority boost for task-A. Task-B goes to sleep until the
lock has been made available. Task-A is already runnable (but not active),
so it receives no wake up.

The reality now is that task-A gets on the CPU once the scheduler decides
to remove the current task despite the fact that a high priority task is
enqueued and waiting. This may take a long time.

The desired behaviour is that CPU0 immediately reschedules after the
priority boost which made task-A the task with the lowest priority.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fixes: fd7a4bed1835 ("sched, rt: Convert switched_{from, to}_rt() prio_changed_rt() to balance callbacks")
Link: http://lkml.kernel.org/r/20170124144006.29821-1-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/deadline.c | 3 +--
 kernel/sched/rt.c       | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 7a72e69fcf65..20e0c9b9ace5 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1772,12 +1772,11 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p)
 #ifdef CONFIG_SMP
 		if (tsk_nr_cpus_allowed(p) > 1 && rq->dl.overloaded)
 			queue_push_tasks(rq);
-#else
+#endif
 		if (dl_task(rq->curr))
 			check_preempt_curr_dl(rq, p, 0);
 		else
 			resched_curr(rq);
-#endif
 	}
 }
 
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 8cf360d309ec..4ac6937f4a65 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -2138,10 +2138,9 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
 #ifdef CONFIG_SMP
 		if (tsk_nr_cpus_allowed(p) > 1 && rq->rt.overloaded)
 			queue_push_tasks(rq);
-#else
+#endif /* CONFIG_SMP */
 		if (p->prio < rq->curr->prio)
 			resched_curr(rq);
-#endif /* CONFIG_SMP */
 	}
 }
 
-- 
2.10.2

[PATCH RT 07/10] lockdep: Handle statically initialized PER_CPU locks proper

[Steven Rostedt]

[-- Attachment #1: 0007-lockdep-Handle-statically-initialized-PER_CPU-locks-.patch --]
[-- Type: text/plain, Size: 9214 bytes --]

4.4.50-rt63-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Thomas Gleixner <tglx@linutronix.de>

If a PER_CPU struct which contains a spin_lock is statically initialized
via:

DEFINE_PER_CPU(struct foo, bla) = {
	.lock = __SPIN_LOCK_UNLOCKED(bla.lock)
};

then lockdep assigns a seperate key to each lock because the logic for
assigning a key to statically initialized locks is to use the address as
the key. With per CPU locks the address is obvioulsy different on each CPU.

That's wrong, because all locks should have the same key.

To solve this the following modifications are required:

 1) Extend the is_kernel/module_percpu_addr() functions to hand back the
    canonical address of the per CPU address, i.e. the per CPU address
    minus the per CPU offset.

 2) Check the lock address with these functions and if the per CPU check
    matches use the returned canonical address as the lock key, so all per
    CPU locks have the same key.

 3) Move the static_obj(key) check into look_up_lock_class() so this check
    can be avoided for statically initialized per CPU locks.  That's
    required because the canonical address fails the static_obj(key) check
    for obvious reasons.

Reported-by: Mike Galbraith <efault@gmx.de>
Cc: stable-rt@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/module.h   |  1 +
 include/linux/percpu.h   |  1 +
 kernel/locking/lockdep.c | 33 +++++++++++++++++++++++----------
 kernel/module.c          | 31 +++++++++++++++++++------------
 mm/percpu.c              | 37 +++++++++++++++++++++++--------------
 5 files changed, 67 insertions(+), 36 deletions(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index b229a9961d02..52538d6b624c 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -500,6 +500,7 @@ static inline int module_is_live(struct module *mod)
 struct module *__module_text_address(unsigned long addr);
 struct module *__module_address(unsigned long addr);
 bool is_module_address(unsigned long addr);
+bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
 bool is_module_percpu_address(unsigned long addr);
 bool is_module_text_address(unsigned long addr);
 
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 53a60a51c758..4ecc057b6e27 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -145,6 +145,7 @@ extern int __init pcpu_page_first_chunk(size_t reserved_size,
 #endif
 
 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
+extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
 extern bool is_kernel_percpu_address(unsigned long addr);
 
 #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index e98ee958a353..fd54dbf686cc 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -668,6 +668,7 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
 	struct lockdep_subclass_key *key;
 	struct list_head *hash_head;
 	struct lock_class *class;
+	bool is_static = false;
 
 #ifdef CONFIG_DEBUG_LOCKDEP
 	/*
@@ -695,10 +696,23 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
 
 	/*
 	 * Static locks do not have their class-keys yet - for them the key
-	 * is the lock object itself:
+	 * is the lock object itself. If the lock is in the per cpu area,
+	 * the canonical address of the lock (per cpu offset removed) is
+	 * used.
 	 */
-	if (unlikely(!lock->key))
-		lock->key = (void *)lock;
+	if (unlikely(!lock->key)) {
+		unsigned long can_addr, addr = (unsigned long)lock;
+
+		if (__is_kernel_percpu_address(addr, &can_addr))
+			lock->key = (void *)can_addr;
+		else if (__is_module_percpu_address(addr, &can_addr))
+			lock->key = (void *)can_addr;
+		else if (static_obj(lock))
+			lock->key = (void *)lock;
+		else
+			return ERR_PTR(-EINVAL);
+		is_static = true;
+	}
 
 	/*
 	 * NOTE: the class-key must be unique. For dynamic locks, a static
@@ -730,7 +744,7 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
 		}
 	}
 
-	return NULL;
+	return is_static || static_obj(lock->key) ? NULL : ERR_PTR(-EINVAL);
 }
 
 /*
@@ -748,19 +762,18 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
 	DEBUG_LOCKS_WARN_ON(!irqs_disabled());
 
 	class = look_up_lock_class(lock, subclass);
-	if (likely(class))
+	if (likely(!IS_ERR_OR_NULL(class)))
 		goto out_set_class_cache;
 
 	/*
 	 * Debug-check: all keys must be persistent!
- 	 */
-	if (!static_obj(lock->key)) {
+	 */
+	if (IS_ERR(class)) {
 		debug_locks_off();
 		printk("INFO: trying to register non-static key.\n");
 		printk("the code is fine but needs lockdep annotation.\n");
 		printk("turning off the locking correctness validator.\n");
 		dump_stack();
-
 		return NULL;
 	}
 
@@ -3278,7 +3291,7 @@ static int match_held_lock(struct held_lock *hlock, struct lockdep_map *lock)
 		 * Clearly if the lock hasn't been acquired _ever_, we're not
 		 * holding it either, so report failure.
 		 */
-		if (!class)
+		if (IS_ERR_OR_NULL(class))
 			return 0;
 
 		/*
@@ -3979,7 +3992,7 @@ void lockdep_reset_lock(struct lockdep_map *lock)
 		 * If the class exists we look it up and zap it:
 		 */
 		class = look_up_lock_class(lock, j);
-		if (class)
+		if (!IS_ERR_OR_NULL(class))
 			zap_class(class);
 	}
 	/*
diff --git a/kernel/module.c b/kernel/module.c
index b14a4f31221f..31a41894f28f 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -682,16 +682,7 @@ static void percpu_modcopy(struct module *mod,
 		memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
 }
 
-/**
- * is_module_percpu_address - test whether address is from module static percpu
- * @addr: address to test
- *
- * Test whether @addr belongs to module static percpu area.
- *
- * RETURNS:
- * %true if @addr is from module static percpu area
- */
-bool is_module_percpu_address(unsigned long addr)
+bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
 {
 	struct module *mod;
 	unsigned int cpu;
@@ -705,9 +696,11 @@ bool is_module_percpu_address(unsigned long addr)
 			continue;
 		for_each_possible_cpu(cpu) {
 			void *start = per_cpu_ptr(mod->percpu, cpu);
+			void *va = (void *)addr;
 
-			if ((void *)addr >= start &&
-			    (void *)addr < start + mod->percpu_size) {
+			if (va >= start && va < start + mod->percpu_size) {
+				if (can_addr)
+					*can_addr = (unsigned long) (va - start);
 				preempt_enable();
 				return true;
 			}
@@ -718,6 +711,20 @@ bool is_module_percpu_address(unsigned long addr)
 	return false;
 }
 
+/**
+ * is_module_percpu_address - test whether address is from module static percpu
+ * @addr: address to test
+ *
+ * Test whether @addr belongs to module static percpu area.
+ *
+ * RETURNS:
+ * %true if @addr is from module static percpu area
+ */
+bool is_module_percpu_address(unsigned long addr)
+{
+	return __is_module_percpu_address(addr, NULL);
+}
+
 #else /* ... !CONFIG_SMP */
 
 static inline void __percpu *mod_percpu(struct module *mod)
diff --git a/mm/percpu.c b/mm/percpu.c
index 1f376bce413c..3b9a49d4f33c 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1282,18 +1282,7 @@ void free_percpu(void __percpu *ptr)
 }
 EXPORT_SYMBOL_GPL(free_percpu);
 
-/**
- * is_kernel_percpu_address - test whether address is from static percpu area
- * @addr: address to test
- *
- * Test whether @addr belongs to in-kernel static percpu area.  Module
- * static percpu areas are not considered.  For those, use
- * is_module_percpu_address().
- *
- * RETURNS:
- * %true if @addr is from in-kernel static percpu area, %false otherwise.
- */
-bool is_kernel_percpu_address(unsigned long addr)
+bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr)
 {
 #ifdef CONFIG_SMP
 	const size_t static_size = __per_cpu_end - __per_cpu_start;
@@ -1302,16 +1291,36 @@ bool is_kernel_percpu_address(unsigned long addr)
 
 	for_each_possible_cpu(cpu) {
 		void *start = per_cpu_ptr(base, cpu);
+		void *va = (void *)addr;
 
-		if ((void *)addr >= start && (void *)addr < start + static_size)
+		if (va >= start && va < start + static_size) {
+			if (can_addr)
+				*can_addr = (unsigned long) (va - start);
 			return true;
-        }
+		}
+	}
 #endif
 	/* on UP, can't distinguish from other static vars, always false */
 	return false;
 }
 
 /**
+ * is_kernel_percpu_address - test whether address is from static percpu area
+ * @addr: address to test
+ *
+ * Test whether @addr belongs to in-kernel static percpu area.  Module
+ * static percpu areas are not considered.  For those, use
+ * is_module_percpu_address().
+ *
+ * RETURNS:
+ * %true if @addr is from in-kernel static percpu area, %false otherwise.
+ */
+bool is_kernel_percpu_address(unsigned long addr)
+{
+	return __is_kernel_percpu_address(addr, NULL);
+}
+
+/**
  * per_cpu_ptr_to_phys - convert translated percpu address to physical address
  * @addr: the address to be converted to physical address
  *
-- 
2.10.2

[PATCH RT 08/10] rt: Drop the removal of _GPL from rt_mutex_destroy()s EXPORT_SYMBOL

[Steven Rostedt]

[-- Attachment #1: 0008-rt-Drop-the-removal-of-_GPL-from-rt_mutex_destroy-s-.patch --]
[-- Type: text/plain, Size: 886 bytes --]

4.4.50-rt63-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

What we have now should be enough, the EXPORT_SYMBOL statement for
rt_mutex_destroy() is not required.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/locking/rtmutex.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 56f5f1a9baf8..0e9a6260441d 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -2216,7 +2216,8 @@ void rt_mutex_destroy(struct rt_mutex *lock)
 	lock->magic = NULL;
 #endif
 }
-EXPORT_SYMBOL(rt_mutex_destroy);
+
+EXPORT_SYMBOL_GPL(rt_mutex_destroy);
 
 /**
  * __rt_mutex_init - initialize the rt lock
-- 
2.10.2

[PATCH RT 09/10] lockdep: Fix compilation error for !CONFIG_MODULES and !CONFIG_SMP

[Steven Rostedt]

[-- Attachment #1: 0009-lockdep-Fix-compilation-error-for-CONFIG_MODULES-and.patch --]
[-- Type: text/plain, Size: 1938 bytes --]

4.4.50-rt63-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Dan Murphy <dmurphy@ti.com>

When CONFIG_MODULES is not set then it fails to compile in lockdep:

|kernel/locking/lockdep.c: In function 'look_up_lock_class':
|kernel/locking/lockdep.c:684:12: error: implicit declaration of function
| '__is_module_percpu_address' [-Werror=implicit-function-declaration]

If CONFIG_MODULES is set but CONFIG_SMP is not, then it compiles but
fails link at the end:

|kernel/locking/lockdep.c:684: undefined reference to `__is_module_percpu_address'
|kernel/built-in.o:(.debug_addr+0x1e674): undefined reference to `__is_module_percpu_address'

This patch adds the function for both cases.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
[bigeasy: merge the two patches from Dan into one, adapt changelog]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/module.h | 5 +++++
 kernel/module.c        | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/include/linux/module.h b/include/linux/module.h
index 52538d6b624c..5fea847cf95c 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -666,6 +666,11 @@ static inline bool is_module_percpu_address(unsigned long addr)
 	return false;
 }
 
+static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
+{
+	return false;
+}
+
 static inline bool is_module_text_address(unsigned long addr)
 {
 	return false;
diff --git a/kernel/module.c b/kernel/module.c
index 31a41894f28f..be3f497a089d 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -756,6 +756,11 @@ bool is_module_percpu_address(unsigned long addr)
 	return false;
 }
 
+bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
+{
+	return false;
+}
+
 #endif /* CONFIG_SMP */
 
 #define MODINFO_ATTR(field)	\
-- 
2.10.2

[PATCH RT 10/10] Linux 4.4.50-rt63-rc1

[Steven Rostedt]

[-- Attachment #1: 0010-Linux-4.4.50-rt63-rc1.patch --]
[-- Type: text/plain, Size: 411 bytes --]

4.4.50-rt63-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

---
 localversion-rt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/localversion-rt b/localversion-rt
index 40d81d8e61b6..9c4ed2db9626 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt62
+-rt63-rc1
-- 
2.10.2