[gentoo-commits] proj/linux-patches:3.4 commit in: /

["Mike Pagano" <mpagano@gentoo.org>]

commit:     a8a5bb77ad98f84e3bc415ffcb4953058ca6c37d
Author:     Mike Pagano <mpagano <AT> gentoo <DOT> org>
AuthorDate: Fri Jul 18 11:33:46 2014 +0000
Commit:     Mike Pagano <mpagano <AT> gentoo <DOT> org>
CommitDate: Fri Jul 18 11:33:46 2014 +0000
URL:        http://git.overlays.gentoo.org/gitweb/?p=proj/linux-patches.git;a=commit;h=a8a5bb77

Linux patch 3.4.99

---
 0000_README             |   4 +
 1098_linux-3.4.99.patch | 797 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 801 insertions(+)

diff --git a/0000_README b/0000_README
index 3c72076..d5d9d81 100644
--- a/0000_README
+++ b/0000_README
@@ -431,6 +431,10 @@ Patch:  1097_linux-3.4.98.patch
 From:   http://www.kernel.org
 Desc:   Linux 3.4.98
 
+Patch:  1098_linux-3.4.99.patch
+From:   http://www.kernel.org
+Desc:   Linux 3.4.99
+
 Patch:  1500_XATTR_USER_PREFIX.patch
 From:   https://bugs.gentoo.org/show_bug.cgi?id=470644
 Desc:   Support for namespace user.pax.* on tmpfs.

diff --git a/1098_linux-3.4.99.patch b/1098_linux-3.4.99.patch
new file mode 100644
index 0000000..8bde200
--- /dev/null
+++ b/1098_linux-3.4.99.patch
@@ -0,0 +1,797 @@
+diff --git a/Makefile b/Makefile
+index d277446ee8ee..ed97caf40f71 100644
+--- a/Makefile
++++ b/Makefile
+@@ -1,6 +1,6 @@
+ VERSION = 3
+ PATCHLEVEL = 4
+-SUBLEVEL = 98
++SUBLEVEL = 99
+ EXTRAVERSION =
+ NAME = Saber-toothed Squirrel
+ 
+diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
+index 02aee03e713c..1eef567f177a 100644
+--- a/arch/powerpc/perf/core-book3s.c
++++ b/arch/powerpc/perf/core-book3s.c
+@@ -472,7 +472,22 @@ static void power_pmu_read(struct perf_event *event)
+ 	} while (local64_cmpxchg(&event->hw.prev_count, prev, val) != prev);
+ 
+ 	local64_add(delta, &event->count);
+-	local64_sub(delta, &event->hw.period_left);
++
++	/*
++	 * A number of places program the PMC with (0x80000000 - period_left).
++	 * We never want period_left to be less than 1 because we will program
++	 * the PMC with a value >= 0x800000000 and an edge detected PMC will
++	 * roll around to 0 before taking an exception. We have seen this
++	 * on POWER8.
++	 *
++	 * To fix this, clamp the minimum value of period_left to 1.
++	 */
++	do {
++		prev = local64_read(&event->hw.period_left);
++		val = prev - delta;
++		if (val < 1)
++			val = 1;
++	} while (local64_cmpxchg(&event->hw.period_left, prev, val) != prev);
+ }
+ 
+ /*
+diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
+index be1ef574ce9a..dec49d34c048 100644
+--- a/arch/x86/mm/ioremap.c
++++ b/arch/x86/mm/ioremap.c
+@@ -50,6 +50,21 @@ int ioremap_change_attr(unsigned long vaddr, unsigned long size,
+ 	return err;
+ }
+ 
++static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages,
++			       void *arg)
++{
++	unsigned long i;
++
++	for (i = 0; i < nr_pages; ++i)
++		if (pfn_valid(start_pfn + i) &&
++		    !PageReserved(pfn_to_page(start_pfn + i)))
++			return 1;
++
++	WARN_ONCE(1, "ioremap on RAM pfn 0x%lx\n", start_pfn);
++
++	return 0;
++}
++
+ /*
+  * Remap an arbitrary physical address space into the kernel virtual
+  * address space. Needed when the kernel wants to access high addresses
+@@ -93,14 +108,11 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
+ 	/*
+ 	 * Don't allow anybody to remap normal RAM that we're using..
+ 	 */
++	pfn      = phys_addr >> PAGE_SHIFT;
+ 	last_pfn = last_addr >> PAGE_SHIFT;
+-	for (pfn = phys_addr >> PAGE_SHIFT; pfn <= last_pfn; pfn++) {
+-		int is_ram = page_is_ram(pfn);
+-
+-		if (is_ram && pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)))
+-			return NULL;
+-		WARN_ON_ONCE(is_ram);
+-	}
++	if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
++				  __ioremap_check_ram) == 1)
++		return NULL;
+ 
+ 	/*
+ 	 * Mappings have to be page-aligned
+diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
+index 9bdfcf50a190..93f3034ea85d 100644
+--- a/drivers/acpi/battery.c
++++ b/drivers/acpi/battery.c
+@@ -34,6 +34,7 @@
+ #include <linux/dmi.h>
+ #include <linux/slab.h>
+ #include <linux/suspend.h>
++#include <linux/delay.h>
+ #include <asm/unaligned.h>
+ 
+ #ifdef CONFIG_ACPI_PROCFS_POWER
+@@ -1055,6 +1056,28 @@ static int battery_notify(struct notifier_block *nb,
+ 	return 0;
+ }
+ 
++/*
++ * Some machines'(E,G Lenovo Z480) ECs are not stable
++ * during boot up and this causes battery driver fails to be
++ * probed due to failure of getting battery information
++ * from EC sometimes. After several retries, the operation
++ * may work. So add retry code here and 20ms sleep between
++ * every retries.
++ */
++static int acpi_battery_update_retry(struct acpi_battery *battery)
++{
++	int retry, ret;
++
++	for (retry = 5; retry; retry--) {
++		ret = acpi_battery_update(battery);
++		if (!ret)
++			break;
++
++		msleep(20);
++	}
++	return ret;
++}
++
+ static int acpi_battery_add(struct acpi_device *device)
+ {
+ 	int result = 0;
+@@ -1074,9 +1097,11 @@ static int acpi_battery_add(struct acpi_device *device)
+ 	if (ACPI_SUCCESS(acpi_get_handle(battery->device->handle,
+ 			"_BIX", &handle)))
+ 		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
+-	result = acpi_battery_update(battery);
++
++	result = acpi_battery_update_retry(battery);
+ 	if (result)
+ 		goto fail;
++
+ #ifdef CONFIG_ACPI_PROCFS_POWER
+ 	result = acpi_battery_add_fs(device);
+ #endif
+diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
+index 52480010156d..739eb0d0d12d 100644
+--- a/drivers/gpu/drm/radeon/rs600.c
++++ b/drivers/gpu/drm/radeon/rs600.c
+@@ -539,8 +539,10 @@ int rs600_gart_set_page(struct radeon_device *rdev, int i, uint64_t addr)
+ 		return -EINVAL;
+ 	}
+ 	addr = addr & 0xFFFFFFFFFFFFF000ULL;
+-	addr |= R600_PTE_VALID | R600_PTE_SYSTEM | R600_PTE_SNOOPED;
+-	addr |= R600_PTE_READABLE | R600_PTE_WRITEABLE;
++	if (addr != rdev->dummy_page.addr)
++		addr |= R600_PTE_VALID | R600_PTE_READABLE |
++			R600_PTE_WRITEABLE;
++	addr |= R600_PTE_SYSTEM | R600_PTE_SNOOPED;
+ 	writeq(addr, ptr + (i * 8));
+ 	return 0;
+ }
+diff --git a/drivers/hwmon/adm1029.c b/drivers/hwmon/adm1029.c
+index 80cc465d8ac7..f078baef90fe 100644
+--- a/drivers/hwmon/adm1029.c
++++ b/drivers/hwmon/adm1029.c
+@@ -231,6 +231,9 @@ static ssize_t set_fan_div(struct device *dev,
+ 	/* Update the value */
+ 	reg = (reg & 0x3F) | (val << 6);
+ 
++	/* Update the cache */
++	data->fan_div[attr->index] = reg;
++
+ 	/* Write value */
+ 	i2c_smbus_write_byte_data(client,
+ 				  ADM1029_REG_FAN_DIV[attr->index], reg);
+diff --git a/drivers/hwmon/amc6821.c b/drivers/hwmon/amc6821.c
+index f600fa1f92e3..1d2bace45287 100644
+--- a/drivers/hwmon/amc6821.c
++++ b/drivers/hwmon/amc6821.c
+@@ -715,7 +715,7 @@ static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO,
+ 	get_temp_alarm, NULL, IDX_TEMP1_MAX);
+ static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO,
+ 	get_temp_alarm, NULL, IDX_TEMP1_CRIT);
+-static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO | S_IWUSR,
++static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO,
+ 	get_temp, NULL, IDX_TEMP2_INPUT);
+ static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR, get_temp,
+ 	set_temp, IDX_TEMP2_MIN);
+diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
+index 3bd9bd49ed9a..ac339570a805 100644
+--- a/drivers/usb/serial/cp210x.c
++++ b/drivers/usb/serial/cp210x.c
+@@ -159,6 +159,7 @@ static const struct usb_device_id id_table[] = {
+ 	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
+ 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
+ 	{ USB_DEVICE(0x1ADB, 0x0001) }, /* Schweitzer Engineering C662 Cable */
++	{ USB_DEVICE(0x1B1C, 0x1C00) }, /* Corsair USB Dongle */
+ 	{ USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
+ 	{ USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */
+ 	{ USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */
+diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
+index ed1650fb910d..89b5664aa53b 100644
+--- a/drivers/usb/serial/ftdi_sio.c
++++ b/drivers/usb/serial/ftdi_sio.c
+@@ -731,7 +731,8 @@ static struct usb_device_id id_table_combined [] = {
+ 	{ USB_DEVICE(FTDI_VID, FTDI_ACG_HFDUAL_PID) },
+ 	{ USB_DEVICE(FTDI_VID, FTDI_YEI_SERVOCENTER31_PID) },
+ 	{ USB_DEVICE(FTDI_VID, FTDI_THORLABS_PID) },
+-	{ USB_DEVICE(TESTO_VID, TESTO_USB_INTERFACE_PID) },
++	{ USB_DEVICE(TESTO_VID, TESTO_1_PID) },
++	{ USB_DEVICE(TESTO_VID, TESTO_3_PID) },
+ 	{ USB_DEVICE(FTDI_VID, FTDI_GAMMA_SCOUT_PID) },
+ 	{ USB_DEVICE(FTDI_VID, FTDI_TACTRIX_OPENPORT_13M_PID) },
+ 	{ USB_DEVICE(FTDI_VID, FTDI_TACTRIX_OPENPORT_13S_PID) },
+diff --git a/drivers/usb/serial/ftdi_sio_ids.h b/drivers/usb/serial/ftdi_sio_ids.h
+index 500474c48f4b..106cc16cc6ed 100644
+--- a/drivers/usb/serial/ftdi_sio_ids.h
++++ b/drivers/usb/serial/ftdi_sio_ids.h
+@@ -798,7 +798,8 @@
+  * Submitted by Colin Leroy
+  */
+ #define TESTO_VID			0x128D
+-#define TESTO_USB_INTERFACE_PID		0x0001
++#define TESTO_1_PID			0x0001
++#define TESTO_3_PID			0x0003
+ 
+ /*
+  * Mobility Electronics products.
+diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
+index 58fcaa5ae548..e1e05bad2be0 100644
+--- a/drivers/usb/serial/option.c
++++ b/drivers/usb/serial/option.c
+@@ -1501,6 +1501,8 @@ static const struct usb_device_id option_ids[] = {
+ 		.driver_info = (kernel_ulong_t)&net_intf2_blacklist },
+ 	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1426, 0xff, 0xff, 0xff),  /* ZTE MF91 */
+ 		.driver_info = (kernel_ulong_t)&net_intf2_blacklist },
++	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1428, 0xff, 0xff, 0xff),  /* Telewell TW-LTE 4G v2 */
++		.driver_info = (kernel_ulong_t)&net_intf2_blacklist },
+ 	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1533, 0xff, 0xff, 0xff) },
+ 	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1534, 0xff, 0xff, 0xff) },
+ 	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x1535, 0xff, 0xff, 0xff) },
+diff --git a/fs/ext4/super.c b/fs/ext4/super.c
+index 0b0c03c878e5..f0e4e46867f7 100644
+--- a/fs/ext4/super.c
++++ b/fs/ext4/super.c
+@@ -2589,10 +2589,11 @@ static void print_daily_error_info(unsigned long arg)
+ 	es = sbi->s_es;
+ 
+ 	if (es->s_error_count)
+-		ext4_msg(sb, KERN_NOTICE, "error count: %u",
++		/* fsck newer than v1.41.13 is needed to clean this condition. */
++		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
+ 			 le32_to_cpu(es->s_error_count));
+ 	if (es->s_first_error_time) {
+-		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
++		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
+ 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
+ 		       (int) sizeof(es->s_first_error_func),
+ 		       es->s_first_error_func,
+@@ -2606,7 +2607,7 @@ static void print_daily_error_info(unsigned long arg)
+ 		printk("\n");
+ 	}
+ 	if (es->s_last_error_time) {
+-		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
++		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
+ 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
+ 		       (int) sizeof(es->s_last_error_func),
+ 		       es->s_last_error_func,
+diff --git a/kernel/cpuset.c b/kernel/cpuset.c
+index 4b843ace285c..9cb82b9aeb73 100644
+--- a/kernel/cpuset.c
++++ b/kernel/cpuset.c
+@@ -1152,7 +1152,13 @@ done:
+ 
+ int current_cpuset_is_being_rebound(void)
+ {
+-	return task_cs(current) == cpuset_being_rebound;
++	int ret;
++
++	rcu_read_lock();
++	ret = task_cs(current) == cpuset_being_rebound;
++	rcu_read_unlock();
++
++	return ret;
+ }
+ 
+ static int update_relax_domain_level(struct cpuset *cs, s64 val)
+diff --git a/kernel/rtmutex-debug.h b/kernel/rtmutex-debug.h
+index 14193d596d78..ab29b6a22669 100644
+--- a/kernel/rtmutex-debug.h
++++ b/kernel/rtmutex-debug.h
+@@ -31,3 +31,8 @@ static inline int debug_rt_mutex_detect_deadlock(struct rt_mutex_waiter *waiter,
+ {
+ 	return (waiter != NULL);
+ }
++
++static inline void rt_mutex_print_deadlock(struct rt_mutex_waiter *w)
++{
++	debug_rt_mutex_print_deadlock(w);
++}
+diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
+index a242e691c993..375ae48479fa 100644
+--- a/kernel/rtmutex.c
++++ b/kernel/rtmutex.c
+@@ -81,6 +81,47 @@ static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
+ 		owner = *p;
+ 	} while (cmpxchg(p, owner, owner | RT_MUTEX_HAS_WAITERS) != owner);
+ }
++
++/*
++ * Safe fastpath aware unlock:
++ * 1) Clear the waiters bit
++ * 2) Drop lock->wait_lock
++ * 3) Try to unlock the lock with cmpxchg
++ */
++static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock)
++	__releases(lock->wait_lock)
++{
++	struct task_struct *owner = rt_mutex_owner(lock);
++
++	clear_rt_mutex_waiters(lock);
++	raw_spin_unlock(&lock->wait_lock);
++	/*
++	 * If a new waiter comes in between the unlock and the cmpxchg
++	 * we have two situations:
++	 *
++	 * unlock(wait_lock);
++	 *					lock(wait_lock);
++	 * cmpxchg(p, owner, 0) == owner
++	 *					mark_rt_mutex_waiters(lock);
++	 *					acquire(lock);
++	 * or:
++	 *
++	 * unlock(wait_lock);
++	 *					lock(wait_lock);
++	 *					mark_rt_mutex_waiters(lock);
++	 *
++	 * cmpxchg(p, owner, 0) != owner
++	 *					enqueue_waiter();
++	 *					unlock(wait_lock);
++	 * lock(wait_lock);
++	 * wake waiter();
++	 * unlock(wait_lock);
++	 *					lock(wait_lock);
++	 *					acquire(lock);
++	 */
++	return rt_mutex_cmpxchg(lock, owner, NULL);
++}
++
+ #else
+ # define rt_mutex_cmpxchg(l,c,n)	(0)
+ static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
+@@ -88,6 +129,17 @@ static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
+ 	lock->owner = (struct task_struct *)
+ 			((unsigned long)lock->owner | RT_MUTEX_HAS_WAITERS);
+ }
++
++/*
++ * Simple slow path only version: lock->owner is protected by lock->wait_lock.
++ */
++static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock)
++	__releases(lock->wait_lock)
++{
++	lock->owner = NULL;
++	raw_spin_unlock(&lock->wait_lock);
++	return true;
++}
+ #endif
+ 
+ /*
+@@ -141,6 +193,11 @@ static void rt_mutex_adjust_prio(struct task_struct *task)
+  */
+ int max_lock_depth = 1024;
+ 
++static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p)
++{
++	return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL;
++}
++
+ /*
+  * Adjust the priority chain. Also used for deadlock detection.
+  * Decreases task's usage by one - may thus free the task.
+@@ -149,6 +206,7 @@ int max_lock_depth = 1024;
+ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
+ 				      int deadlock_detect,
+ 				      struct rt_mutex *orig_lock,
++				      struct rt_mutex *next_lock,
+ 				      struct rt_mutex_waiter *orig_waiter,
+ 				      struct task_struct *top_task)
+ {
+@@ -182,7 +240,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
+ 		}
+ 		put_task_struct(task);
+ 
+-		return deadlock_detect ? -EDEADLK : 0;
++		return -EDEADLK;
+ 	}
+  retry:
+ 	/*
+@@ -207,13 +265,32 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
+ 		goto out_unlock_pi;
+ 
+ 	/*
++	 * We dropped all locks after taking a refcount on @task, so
++	 * the task might have moved on in the lock chain or even left
++	 * the chain completely and blocks now on an unrelated lock or
++	 * on @orig_lock.
++	 *
++	 * We stored the lock on which @task was blocked in @next_lock,
++	 * so we can detect the chain change.
++	 */
++	if (next_lock != waiter->lock)
++		goto out_unlock_pi;
++
++	/*
+ 	 * Drop out, when the task has no waiters. Note,
+ 	 * top_waiter can be NULL, when we are in the deboosting
+ 	 * mode!
+ 	 */
+-	if (top_waiter && (!task_has_pi_waiters(task) ||
+-			   top_waiter != task_top_pi_waiter(task)))
+-		goto out_unlock_pi;
++	if (top_waiter) {
++		if (!task_has_pi_waiters(task))
++			goto out_unlock_pi;
++		/*
++		 * If deadlock detection is off, we stop here if we
++		 * are not the top pi waiter of the task.
++		 */
++		if (!detect_deadlock && top_waiter != task_top_pi_waiter(task))
++			goto out_unlock_pi;
++	}
+ 
+ 	/*
+ 	 * When deadlock detection is off then we check, if further
+@@ -229,11 +306,16 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
+ 		goto retry;
+ 	}
+ 
+-	/* Deadlock detection */
++	/*
++	 * Deadlock detection. If the lock is the same as the original
++	 * lock which caused us to walk the lock chain or if the
++	 * current lock is owned by the task which initiated the chain
++	 * walk, we detected a deadlock.
++	 */
+ 	if (lock == orig_lock || rt_mutex_owner(lock) == top_task) {
+ 		debug_rt_mutex_deadlock(deadlock_detect, orig_waiter, lock);
+ 		raw_spin_unlock(&lock->wait_lock);
+-		ret = deadlock_detect ? -EDEADLK : 0;
++		ret = -EDEADLK;
+ 		goto out_unlock_pi;
+ 	}
+ 
+@@ -280,11 +362,26 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
+ 		__rt_mutex_adjust_prio(task);
+ 	}
+ 
++	/*
++	 * Check whether the task which owns the current lock is pi
++	 * blocked itself. If yes we store a pointer to the lock for
++	 * the lock chain change detection above. After we dropped
++	 * task->pi_lock next_lock cannot be dereferenced anymore.
++	 */
++	next_lock = task_blocked_on_lock(task);
++
+ 	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ 
+ 	top_waiter = rt_mutex_top_waiter(lock);
+ 	raw_spin_unlock(&lock->wait_lock);
+ 
++	/*
++	 * We reached the end of the lock chain. Stop right here. No
++	 * point to go back just to figure that out.
++	 */
++	if (!next_lock)
++		goto out_put_task;
++
+ 	if (!detect_deadlock && waiter != top_waiter)
+ 		goto out_put_task;
+ 
+@@ -395,8 +492,21 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
+ {
+ 	struct task_struct *owner = rt_mutex_owner(lock);
+ 	struct rt_mutex_waiter *top_waiter = waiter;
+-	unsigned long flags;
++	struct rt_mutex *next_lock;
+ 	int chain_walk = 0, res;
++	unsigned long flags;
++
++	/*
++	 * Early deadlock detection. We really don't want the task to
++	 * enqueue on itself just to untangle the mess later. It's not
++	 * only an optimization. We drop the locks, so another waiter
++	 * can come in before the chain walk detects the deadlock. So
++	 * the other will detect the deadlock and return -EDEADLOCK,
++	 * which is wrong, as the other waiter is not in a deadlock
++	 * situation.
++	 */
++	if (owner == task)
++		return -EDEADLK;
+ 
+ 	raw_spin_lock_irqsave(&task->pi_lock, flags);
+ 	__rt_mutex_adjust_prio(task);
+@@ -417,20 +527,28 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
+ 	if (!owner)
+ 		return 0;
+ 
++	raw_spin_lock_irqsave(&owner->pi_lock, flags);
+ 	if (waiter == rt_mutex_top_waiter(lock)) {
+-		raw_spin_lock_irqsave(&owner->pi_lock, flags);
+ 		plist_del(&top_waiter->pi_list_entry, &owner->pi_waiters);
+ 		plist_add(&waiter->pi_list_entry, &owner->pi_waiters);
+ 
+ 		__rt_mutex_adjust_prio(owner);
+ 		if (owner->pi_blocked_on)
+ 			chain_walk = 1;
+-		raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
+-	}
+-	else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock))
++	} else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock)) {
+ 		chain_walk = 1;
++	}
++
++	/* Store the lock on which owner is blocked or NULL */
++	next_lock = task_blocked_on_lock(owner);
+ 
+-	if (!chain_walk)
++	raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
++	/*
++	 * Even if full deadlock detection is on, if the owner is not
++	 * blocked itself, we can avoid finding this out in the chain
++	 * walk.
++	 */
++	if (!chain_walk || !next_lock)
+ 		return 0;
+ 
+ 	/*
+@@ -442,8 +560,8 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
+ 
+ 	raw_spin_unlock(&lock->wait_lock);
+ 
+-	res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter,
+-					 task);
++	res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock,
++					 next_lock, waiter, task);
+ 
+ 	raw_spin_lock(&lock->wait_lock);
+ 
+@@ -453,7 +571,8 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
+ /*
+  * Wake up the next waiter on the lock.
+  *
+- * Remove the top waiter from the current tasks waiter list and wake it up.
++ * Remove the top waiter from the current tasks pi waiter list and
++ * wake it up.
+  *
+  * Called with lock->wait_lock held.
+  */
+@@ -474,10 +593,23 @@ static void wakeup_next_waiter(struct rt_mutex *lock)
+ 	 */
+ 	plist_del(&waiter->pi_list_entry, &current->pi_waiters);
+ 
+-	rt_mutex_set_owner(lock, NULL);
++	/*
++	 * As we are waking up the top waiter, and the waiter stays
++	 * queued on the lock until it gets the lock, this lock
++	 * obviously has waiters. Just set the bit here and this has
++	 * the added benefit of forcing all new tasks into the
++	 * slow path making sure no task of lower priority than
++	 * the top waiter can steal this lock.
++	 */
++	lock->owner = (void *) RT_MUTEX_HAS_WAITERS;
+ 
+ 	raw_spin_unlock_irqrestore(&current->pi_lock, flags);
+ 
++	/*
++	 * It's safe to dereference waiter as it cannot go away as
++	 * long as we hold lock->wait_lock. The waiter task needs to
++	 * acquire it in order to dequeue the waiter.
++	 */
+ 	wake_up_process(waiter->task);
+ }
+ 
+@@ -492,8 +624,8 @@ static void remove_waiter(struct rt_mutex *lock,
+ {
+ 	int first = (waiter == rt_mutex_top_waiter(lock));
+ 	struct task_struct *owner = rt_mutex_owner(lock);
++	struct rt_mutex *next_lock = NULL;
+ 	unsigned long flags;
+-	int chain_walk = 0;
+ 
+ 	raw_spin_lock_irqsave(&current->pi_lock, flags);
+ 	plist_del(&waiter->list_entry, &lock->wait_list);
+@@ -517,15 +649,15 @@ static void remove_waiter(struct rt_mutex *lock,
+ 		}
+ 		__rt_mutex_adjust_prio(owner);
+ 
+-		if (owner->pi_blocked_on)
+-			chain_walk = 1;
++		/* Store the lock on which owner is blocked or NULL */
++		next_lock = task_blocked_on_lock(owner);
+ 
+ 		raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
+ 	}
+ 
+ 	WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
+ 
+-	if (!chain_walk)
++	if (!next_lock)
+ 		return;
+ 
+ 	/* gets dropped in rt_mutex_adjust_prio_chain()! */
+@@ -533,7 +665,7 @@ static void remove_waiter(struct rt_mutex *lock,
+ 
+ 	raw_spin_unlock(&lock->wait_lock);
+ 
+-	rt_mutex_adjust_prio_chain(owner, 0, lock, NULL, current);
++	rt_mutex_adjust_prio_chain(owner, 0, lock, next_lock, NULL, current);
+ 
+ 	raw_spin_lock(&lock->wait_lock);
+ }
+@@ -546,6 +678,7 @@ static void remove_waiter(struct rt_mutex *lock,
+ void rt_mutex_adjust_pi(struct task_struct *task)
+ {
+ 	struct rt_mutex_waiter *waiter;
++	struct rt_mutex *next_lock;
+ 	unsigned long flags;
+ 
+ 	raw_spin_lock_irqsave(&task->pi_lock, flags);
+@@ -555,12 +688,13 @@ void rt_mutex_adjust_pi(struct task_struct *task)
+ 		raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ 		return;
+ 	}
+-
++	next_lock = waiter->lock;
+ 	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ 
+ 	/* gets dropped in rt_mutex_adjust_prio_chain()! */
+ 	get_task_struct(task);
+-	rt_mutex_adjust_prio_chain(task, 0, NULL, NULL, task);
++
++	rt_mutex_adjust_prio_chain(task, 0, NULL, next_lock, NULL, task);
+ }
+ 
+ /**
+@@ -612,6 +746,26 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state,
+ 	return ret;
+ }
+ 
++static void rt_mutex_handle_deadlock(int res, int detect_deadlock,
++				     struct rt_mutex_waiter *w)
++{
++	/*
++	 * If the result is not -EDEADLOCK or the caller requested
++	 * deadlock detection, nothing to do here.
++	 */
++	if (res != -EDEADLOCK || detect_deadlock)
++		return;
++
++	/*
++	 * Yell lowdly and stop the task right here.
++	 */
++	rt_mutex_print_deadlock(w);
++	while (1) {
++		set_current_state(TASK_INTERRUPTIBLE);
++		schedule();
++	}
++}
++
+ /*
+  * Slow path lock function:
+  */
+@@ -649,8 +803,10 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
+ 
+ 	set_current_state(TASK_RUNNING);
+ 
+-	if (unlikely(ret))
++	if (unlikely(ret)) {
+ 		remove_waiter(lock, &waiter);
++		rt_mutex_handle_deadlock(ret, detect_deadlock, &waiter);
++	}
+ 
+ 	/*
+ 	 * try_to_take_rt_mutex() sets the waiter bit
+@@ -706,12 +862,49 @@ rt_mutex_slowunlock(struct rt_mutex *lock)
+ 
+ 	rt_mutex_deadlock_account_unlock(current);
+ 
+-	if (!rt_mutex_has_waiters(lock)) {
+-		lock->owner = NULL;
+-		raw_spin_unlock(&lock->wait_lock);
+-		return;
++	/*
++	 * We must be careful here if the fast path is enabled. If we
++	 * have no waiters queued we cannot set owner to NULL here
++	 * because of:
++	 *
++	 * foo->lock->owner = NULL;
++	 *			rtmutex_lock(foo->lock);   <- fast path
++	 *			free = atomic_dec_and_test(foo->refcnt);
++	 *			rtmutex_unlock(foo->lock); <- fast path
++	 *			if (free)
++	 *				kfree(foo);
++	 * raw_spin_unlock(foo->lock->wait_lock);
++	 *
++	 * So for the fastpath enabled kernel:
++	 *
++	 * Nothing can set the waiters bit as long as we hold
++	 * lock->wait_lock. So we do the following sequence:
++	 *
++	 *	owner = rt_mutex_owner(lock);
++	 *	clear_rt_mutex_waiters(lock);
++	 *	raw_spin_unlock(&lock->wait_lock);
++	 *	if (cmpxchg(&lock->owner, owner, 0) == owner)
++	 *		return;
++	 *	goto retry;
++	 *
++	 * The fastpath disabled variant is simple as all access to
++	 * lock->owner is serialized by lock->wait_lock:
++	 *
++	 *	lock->owner = NULL;
++	 *	raw_spin_unlock(&lock->wait_lock);
++	 */
++	while (!rt_mutex_has_waiters(lock)) {
++		/* Drops lock->wait_lock ! */
++		if (unlock_rt_mutex_safe(lock) == true)
++			return;
++		/* Relock the rtmutex and try again */
++		raw_spin_lock(&lock->wait_lock);
+ 	}
+ 
++	/*
++	 * The wakeup next waiter path does not suffer from the above
++	 * race. See the comments there.
++	 */
+ 	wakeup_next_waiter(lock);
+ 
+ 	raw_spin_unlock(&lock->wait_lock);
+@@ -958,7 +1151,8 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
+ 		return 1;
+ 	}
+ 
+-	ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock);
++	/* We enforce deadlock detection for futexes */
++	ret = task_blocks_on_rt_mutex(lock, waiter, task, 1);
+ 
+ 	if (ret && !rt_mutex_owner(lock)) {
+ 		/*
+diff --git a/kernel/rtmutex.h b/kernel/rtmutex.h
+index a1a1dd06421d..f6a1f3c133b1 100644
+--- a/kernel/rtmutex.h
++++ b/kernel/rtmutex.h
+@@ -24,3 +24,8 @@
+ #define debug_rt_mutex_print_deadlock(w)		do { } while (0)
+ #define debug_rt_mutex_detect_deadlock(w,d)		(d)
+ #define debug_rt_mutex_reset_waiter(w)			do { } while (0)
++
++static inline void rt_mutex_print_deadlock(struct rt_mutex_waiter *w)
++{
++	WARN(1, "rtmutex deadlock detected\n");
++}
+diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
+index a494ec317e0a..8897a6f5c408 100644
+--- a/kernel/trace/trace.c
++++ b/kernel/trace/trace.c
+@@ -1052,7 +1052,6 @@ void tracing_start(void)
+ 
+ 	arch_spin_unlock(&ftrace_max_lock);
+ 
+-	ftrace_start();
+  out:
+ 	raw_spin_unlock_irqrestore(&tracing_start_lock, flags);
+ }
+@@ -1068,7 +1067,6 @@ void tracing_stop(void)
+ 	struct ring_buffer *buffer;
+ 	unsigned long flags;
+ 
+-	ftrace_stop();
+ 	raw_spin_lock_irqsave(&tracing_start_lock, flags);
+ 	if (trace_stop_count++)
+ 		goto out;
+diff --git a/mm/mempolicy.c b/mm/mempolicy.c
+index ee50c256fdc3..5cec36b6e838 100644
+--- a/mm/mempolicy.c
++++ b/mm/mempolicy.c
+@@ -1991,7 +1991,6 @@ struct mempolicy *__mpol_dup(struct mempolicy *old)
+ 	} else
+ 		*new = *old;
+ 
+-	rcu_read_lock();
+ 	if (current_cpuset_is_being_rebound()) {
+ 		nodemask_t mems = cpuset_mems_allowed(current);
+ 		if (new->flags & MPOL_F_REBINDING)
+@@ -1999,7 +1998,6 @@ struct mempolicy *__mpol_dup(struct mempolicy *old)
+ 		else
+ 			mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE);
+ 	}
+-	rcu_read_unlock();
+ 	atomic_set(&new->refcnt, 1);
+ 	return new;
+ }