* [PATCH RT 1/6] kernel/futex: dont deboost too early
2016-10-30 16:45 [PATCH RT 0/6] Linux 4.4.27-rt38-rc1 Steven Rostedt
@ 2016-10-30 16:45 ` Steven Rostedt
2016-10-30 16:45 ` [PATCH RT 2/6] ftrace: Fix trace header alignment Steven Rostedt
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Steven Rostedt @ 2016-10-30 16:45 UTC (permalink / raw)
To: linux-kernel, linux-rt-users
Cc: Thomas Gleixner, Carsten Emde, Sebastian Andrzej Siewior,
John Kacur, Paul Gortmaker, stable-rt
[-- Attachment #1: 0001-kernel-futex-don-t-deboost-too-early.patch --]
[-- Type: text/plain, Size: 5935 bytes --]
4.4.27-rt38-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
The sequence:
T1 holds futex
T2 blocks on futex and boosts T1
T1 unlocks futex and holds hb->lock
T1 unlocks rt mutex, so T1 has no more pi waiters
T3 blocks on hb->lock and adds itself to the pi waiters list of T1
T1 unlocks hb->lock and deboosts itself
T4 preempts T1 so the wakeup of T2 gets delayed
As a workaround I attempt here do unlock the hb->lock without a deboost
and perform the deboost after the wake up of the waiter.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
include/linux/spinlock.h | 6 +++++
include/linux/spinlock_rt.h | 2 ++
kernel/futex.c | 2 +-
kernel/locking/rtmutex.c | 53 +++++++++++++++++++++++++++++++++++++++------
4 files changed, 55 insertions(+), 8 deletions(-)
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index b241cc044bd3..02928fa5499d 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -355,6 +355,12 @@ static __always_inline void spin_unlock(spinlock_t *lock)
raw_spin_unlock(&lock->rlock);
}
+static __always_inline int spin_unlock_no_deboost(spinlock_t *lock)
+{
+ raw_spin_unlock(&lock->rlock);
+ return 0;
+}
+
static __always_inline void spin_unlock_bh(spinlock_t *lock)
{
raw_spin_unlock_bh(&lock->rlock);
diff --git a/include/linux/spinlock_rt.h b/include/linux/spinlock_rt.h
index 3b2825537531..7eb87584e843 100644
--- a/include/linux/spinlock_rt.h
+++ b/include/linux/spinlock_rt.h
@@ -26,6 +26,7 @@ extern void __lockfunc rt_spin_lock(spinlock_t *lock);
extern unsigned long __lockfunc rt_spin_lock_trace_flags(spinlock_t *lock);
extern void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass);
extern void __lockfunc rt_spin_unlock(spinlock_t *lock);
+extern int __lockfunc rt_spin_unlock_no_deboost(spinlock_t *lock);
extern void __lockfunc rt_spin_unlock_wait(spinlock_t *lock);
extern int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags);
extern int __lockfunc rt_spin_trylock_bh(spinlock_t *lock);
@@ -112,6 +113,7 @@ static inline unsigned long spin_lock_trace_flags(spinlock_t *lock)
#define spin_lock_nest_lock(lock, nest_lock) spin_lock_nested(lock, 0)
#define spin_unlock(lock) rt_spin_unlock(lock)
+#define spin_unlock_no_deboost(lock) rt_spin_unlock_no_deboost(lock)
#define spin_unlock_bh(lock) \
do { \
diff --git a/kernel/futex.c b/kernel/futex.c
index ad38af0bcff3..059623427b99 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1288,7 +1288,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this,
* deboost first (and lose our higher priority), then the task might get
* scheduled away before the wake up can take place.
*/
- spin_unlock(&hb->lock);
+ deboost |= spin_unlock_no_deboost(&hb->lock);
wake_up_q(&wake_q);
wake_up_q_sleeper(&wake_sleeper_q);
if (deboost)
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index fde5e54f1096..6759a798c927 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -939,13 +939,14 @@ static inline void rt_spin_lock_fastlock(struct rt_mutex *lock,
slowfn(lock, do_mig_dis);
}
-static inline void rt_spin_lock_fastunlock(struct rt_mutex *lock,
- void (*slowfn)(struct rt_mutex *lock))
+static inline int rt_spin_lock_fastunlock(struct rt_mutex *lock,
+ int (*slowfn)(struct rt_mutex *lock))
{
- if (likely(rt_mutex_cmpxchg_release(lock, current, NULL)))
+ if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) {
rt_mutex_deadlock_account_unlock(current);
- else
- slowfn(lock);
+ return 0;
+ }
+ return slowfn(lock);
}
#ifdef CONFIG_SMP
/*
@@ -1086,7 +1087,7 @@ static void mark_wakeup_next_waiter(struct wake_q_head *wake_q,
/*
* Slow path to release a rt_mutex spin_lock style
*/
-static void noinline __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
+static int noinline __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
{
unsigned long flags;
WAKE_Q(wake_q);
@@ -1101,7 +1102,7 @@ static void noinline __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
if (!rt_mutex_has_waiters(lock)) {
lock->owner = NULL;
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
- return;
+ return 0;
}
mark_wakeup_next_waiter(&wake_q, &wake_sleeper_q, lock);
@@ -1112,6 +1113,33 @@ static void noinline __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
/* Undo pi boosting.when necessary */
rt_mutex_adjust_prio(current);
+ return 0;
+}
+
+static int noinline __sched rt_spin_lock_slowunlock_no_deboost(struct rt_mutex *lock)
+{
+ unsigned long flags;
+ WAKE_Q(wake_q);
+ WAKE_Q(wake_sleeper_q);
+
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
+
+ debug_rt_mutex_unlock(lock);
+
+ rt_mutex_deadlock_account_unlock(current);
+
+ if (!rt_mutex_has_waiters(lock)) {
+ lock->owner = NULL;
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ return 0;
+ }
+
+ mark_wakeup_next_waiter(&wake_q, &wake_sleeper_q, lock);
+
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ wake_up_q(&wake_q);
+ wake_up_q_sleeper(&wake_sleeper_q);
+ return 1;
}
void __lockfunc rt_spin_lock__no_mg(spinlock_t *lock)
@@ -1166,6 +1194,17 @@ void __lockfunc rt_spin_unlock(spinlock_t *lock)
}
EXPORT_SYMBOL(rt_spin_unlock);
+int __lockfunc rt_spin_unlock_no_deboost(spinlock_t *lock)
+{
+ int ret;
+
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ spin_release(&lock->dep_map, 1, _RET_IP_);
+ ret = rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock_no_deboost);
+ migrate_enable();
+ return ret;
+}
+
void __lockfunc __rt_spin_unlock(struct rt_mutex *lock)
{
rt_spin_lock_fastunlock(lock, rt_spin_lock_slowunlock);
--
2.9.3
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH RT 2/6] ftrace: Fix trace header alignment
2016-10-30 16:45 [PATCH RT 0/6] Linux 4.4.27-rt38-rc1 Steven Rostedt
2016-10-30 16:45 ` [PATCH RT 1/6] kernel/futex: dont deboost too early Steven Rostedt
@ 2016-10-30 16:45 ` Steven Rostedt
2016-10-30 16:45 ` [PATCH RT 3/6] zsmalloc: turn that get_cpu_light() into a local_lock() Steven Rostedt
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Steven Rostedt @ 2016-10-30 16:45 UTC (permalink / raw)
To: linux-kernel, linux-rt-users
Cc: Thomas Gleixner, Carsten Emde, Sebastian Andrzej Siewior,
John Kacur, Paul Gortmaker, stable-rt, Mike Galbraith
[-- Attachment #1: 0002-ftrace-Fix-trace-header-alignment.patch --]
[-- Type: text/plain, Size: 3299 bytes --]
4.4.27-rt38-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Mike Galbraith <umgwanakikbuti@gmail.com>
Line up helper arrows to the right column.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[bigeasy: fixup function tracer header]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/trace/trace.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index aebdbff7d425..cad1a28bfbe2 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2559,17 +2559,17 @@ get_total_entries(struct trace_buffer *buf,
static void print_lat_help_header(struct seq_file *m)
{
- seq_puts(m, "# _--------=> CPU# \n"
- "# / _-------=> irqs-off \n"
- "# | / _------=> need-resched \n"
- "# || / _-----=> need-resched_lazy \n"
- "# ||| / _----=> hardirq/softirq \n"
- "# |||| / _---=> preempt-depth \n"
- "# ||||| / _--=> preempt-lazy-depth\n"
- "# |||||| / _-=> migrate-disable \n"
- "# ||||||| / delay \n"
- "# cmd pid |||||||| time | caller \n"
- "# \\ / |||||||| \\ | / \n");
+ seq_puts(m, "# _--------=> CPU# \n"
+ "# / _-------=> irqs-off \n"
+ "# | / _------=> need-resched \n"
+ "# || / _-----=> need-resched_lazy \n"
+ "# ||| / _----=> hardirq/softirq \n"
+ "# |||| / _---=> preempt-depth \n"
+ "# ||||| / _--=> preempt-lazy-depth\n"
+ "# |||||| / _-=> migrate-disable \n"
+ "# ||||||| / delay \n"
+ "# cmd pid |||||||| time | caller \n"
+ "# \\ / |||||||| \\ | / \n");
}
static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
@@ -2598,11 +2598,11 @@ static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file
"# |/ _-----=> need-resched_lazy\n"
"# || / _---=> hardirq/softirq\n"
"# ||| / _--=> preempt-depth\n"
- "# |||| /_--=> preempt-lazy-depth\n"
- "# ||||| _-=> migrate-disable \n"
- "# ||||| / delay\n"
- "# TASK-PID CPU# |||||| TIMESTAMP FUNCTION\n"
- "# | | | |||||| | |\n");
+ "# |||| / _-=> preempt-lazy-depth\n"
+ "# ||||| / _-=> migrate-disable \n"
+ "# |||||| / delay\n"
+ "# TASK-PID CPU# ||||||| TIMESTAMP FUNCTION\n"
+ "# | | | ||||||| | |\n");
}
void
--
2.9.3
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH RT 3/6] zsmalloc: turn that get_cpu_light() into a local_lock()
2016-10-30 16:45 [PATCH RT 0/6] Linux 4.4.27-rt38-rc1 Steven Rostedt
2016-10-30 16:45 ` [PATCH RT 1/6] kernel/futex: dont deboost too early Steven Rostedt
2016-10-30 16:45 ` [PATCH RT 2/6] ftrace: Fix trace header alignment Steven Rostedt
@ 2016-10-30 16:45 ` Steven Rostedt
2016-10-30 16:45 ` [PATCH RT 4/6] x86/apic: get rid of "warning: acpi_ioapic_lock defined but not used" Steven Rostedt
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Steven Rostedt @ 2016-10-30 16:45 UTC (permalink / raw)
To: linux-kernel, linux-rt-users
Cc: Thomas Gleixner, Carsten Emde, Sebastian Andrzej Siewior,
John Kacur, Paul Gortmaker, stable-rt
[-- Attachment #1: 0003-zsmalloc-turn-that-get_cpu_light-into-a-local_lock.patch --]
[-- Type: text/plain, Size: 1838 bytes --]
4.4.27-rt38-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We might get preempted, grab the same ressource again and then corrupt
the memory.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
mm/zsmalloc.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index b552fd607df8..529552c3716d 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -64,6 +64,7 @@
#include <linux/debugfs.h>
#include <linux/zsmalloc.h>
#include <linux/zpool.h>
+#include <linux/locallock.h>
/*
* This must be power of 2 and greater than of equal to sizeof(link_free).
@@ -403,6 +404,7 @@ static unsigned int get_maxobj_per_zspage(int size, int pages_per_zspage)
/* per-cpu VM mapping areas for zspage accesses that cross page boundaries */
static DEFINE_PER_CPU(struct mapping_area, zs_map_area);
+static DEFINE_LOCAL_IRQ_LOCK(zs_map_area_lock);
static int is_first_page(struct page *page)
{
@@ -1289,7 +1291,7 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle,
class = pool->size_class[class_idx];
off = obj_idx_to_offset(page, obj_idx, class->size);
- area = per_cpu_ptr(&zs_map_area, get_cpu_light());
+ area = &get_locked_var(zs_map_area_lock, zs_map_area);
area->vm_mm = mm;
if (off + class->size <= PAGE_SIZE) {
/* this object is contained entirely within a page */
@@ -1342,7 +1344,7 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
__zs_unmap_object(area, pages, off, class->size);
}
- put_cpu_light();
+ put_locked_var(zs_map_area_lock, zs_map_area);
unpin_tag(handle);
}
EXPORT_SYMBOL_GPL(zs_unmap_object);
--
2.9.3
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH RT 4/6] x86/apic: get rid of "warning: acpi_ioapic_lock defined but not used"
2016-10-30 16:45 [PATCH RT 0/6] Linux 4.4.27-rt38-rc1 Steven Rostedt
` (2 preceding siblings ...)
2016-10-30 16:45 ` [PATCH RT 3/6] zsmalloc: turn that get_cpu_light() into a local_lock() Steven Rostedt
@ 2016-10-30 16:45 ` Steven Rostedt
2016-10-30 16:45 ` [PATCH RT 5/6] kbuild: add -fno-PIE Steven Rostedt
2016-10-30 16:45 ` [PATCH RT 6/6] Linux 4.4.27-rt38-rc1 Steven Rostedt
5 siblings, 0 replies; 7+ messages in thread
From: Steven Rostedt @ 2016-10-30 16:45 UTC (permalink / raw)
To: linux-kernel, linux-rt-users
Cc: Thomas Gleixner, Carsten Emde, Sebastian Andrzej Siewior,
John Kacur, Paul Gortmaker, kbuild test robot
[-- Attachment #1: 0004-x86-apic-get-rid-of-warning-acpi_ioapic_lock-defined.patch --]
[-- Type: text/plain, Size: 1921 bytes --]
4.4.27-rt38-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
kbuild test robot reported this against the -RT tree:
| In file included from include/linux/mutex.h:30:0,
| from include/linux/notifier.h:13,
| from include/linux/memory_hotplug.h:6,
| from include/linux/mmzone.h:777,
| from include/linux/gfp.h:5,
| from include/linux/slab.h:14,
| from include/linux/resource_ext.h:19,
| from include/linux/acpi.h:26,
| from arch/x86/kernel/acpi/boot.c:27:
|>> arch/x86/kernel/acpi/boot.c:90:21: warning: 'acpi_ioapic_lock' defined but not used [-Wunused-variable]
| static DEFINE_MUTEX(acpi_ioapic_lock);
| ^
| include/linux/mutex_rt.h:27:15: note: in definition of macro 'DEFINE_MUTEX'
| struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
^~~~~~~~~
which is also true (as in non-used) for !RT but the compiler does not
emit a warning.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
arch/x86/kernel/acpi/boot.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index e75907601a41..a29fc4f84fc4 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -87,7 +87,9 @@ static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;
* ->ioapic_mutex
* ->ioapic_lock
*/
+#ifdef CONFIG_X86_IO_APIC
static DEFINE_MUTEX(acpi_ioapic_lock);
+#endif
/* --------------------------------------------------------------------------
Boot-time Configuration
--
2.9.3
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH RT 5/6] kbuild: add -fno-PIE
2016-10-30 16:45 [PATCH RT 0/6] Linux 4.4.27-rt38-rc1 Steven Rostedt
` (3 preceding siblings ...)
2016-10-30 16:45 ` [PATCH RT 4/6] x86/apic: get rid of "warning: acpi_ioapic_lock defined but not used" Steven Rostedt
@ 2016-10-30 16:45 ` Steven Rostedt
2016-10-30 16:45 ` [PATCH RT 6/6] Linux 4.4.27-rt38-rc1 Steven Rostedt
5 siblings, 0 replies; 7+ messages in thread
From: Steven Rostedt @ 2016-10-30 16:45 UTC (permalink / raw)
To: linux-kernel, linux-rt-users
Cc: Thomas Gleixner, Carsten Emde, Sebastian Andrzej Siewior,
John Kacur, Paul Gortmaker
[-- Attachment #1: 0005-kbuild-add-fno-PIE.patch --]
[-- Type: text/plain, Size: 970 bytes --]
4.4.27-rt38-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Debian started to build the gcc with -fPIE by default so the kernel
build ends before it starts properly with:
|kernel/bounds.c:1:0: error: code model kernel does not support PIC mode
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Makefile b/Makefile
index 3b2614a0fa1b..e2c9fdc9d22f 100644
--- a/Makefile
+++ b/Makefile
@@ -394,7 +394,7 @@ KBUILD_CPPFLAGS := -D__KERNEL__
KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-fno-strict-aliasing -fno-common \
-Werror-implicit-function-declaration \
- -Wno-format-security \
+ -Wno-format-security -fno-PIE \
-std=gnu89
KBUILD_AFLAGS_KERNEL :=
--
2.9.3
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH RT 6/6] Linux 4.4.27-rt38-rc1
2016-10-30 16:45 [PATCH RT 0/6] Linux 4.4.27-rt38-rc1 Steven Rostedt
` (4 preceding siblings ...)
2016-10-30 16:45 ` [PATCH RT 5/6] kbuild: add -fno-PIE Steven Rostedt
@ 2016-10-30 16:45 ` Steven Rostedt
5 siblings, 0 replies; 7+ messages in thread
From: Steven Rostedt @ 2016-10-30 16:45 UTC (permalink / raw)
To: linux-kernel, linux-rt-users
Cc: Thomas Gleixner, Carsten Emde, Sebastian Andrzej Siewior,
John Kacur, Paul Gortmaker
[-- Attachment #1: 0006-Linux-4.4.27-rt38-rc1.patch --]
[-- Type: text/plain, Size: 411 bytes --]
4.4.27-rt38-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
---
localversion-rt | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/localversion-rt b/localversion-rt
index a3b2408c1da6..625367387621 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt37
+-rt38-rc1
--
2.9.3
^ permalink raw reply related [flat|nested] 7+ messages in thread