Thomas Gleixner b4abf91047 rtmutex: Make wait_lock irq safe ... Sasha reported a lockdep splat about a potential deadlock between RCU boosting rtmutex and the posix timer it_lock. CPU0 CPU1 rtmutex_lock(&rcu->rt_mutex) spin_lock(&rcu->rt_mutex.wait_lock) local_irq_disable() spin_lock(&timer->it_lock) spin_lock(&rcu->mutex.wait_lock) --> Interrupt spin_lock(&timer->it_lock) This is caused by the following code sequence on CPU1 rcu_read_lock() x = lookup(); if (x) spin_lock_irqsave(&x->it_lock); rcu_read_unlock(); return x; We could fix that in the posix timer code by keeping rcu read locked across the spinlocked and irq disabled section, but the above sequence is common and there is no reason not to support it. Taking rt_mutex.wait_lock irq safe prevents the deadlock. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>		2016-01-26 11:08:35 +01:00
..
bpf	net: bpf: reject invalid shifts	2016-01-12 17:06:53 -05:00
configs
debug	module: use a structure to encapsulate layout.	2015-12-04 22:46:25 +01:00
events	wrappers for ->i_mutex access	2016-01-22 18:04:28 -05:00
gcov	gcov: use within_module() helper.	2015-12-04 22:46:25 +01:00
irq	PCI changes for the v4.5 merge window:	2016-01-21 11:52:16 -08:00
livepatch	livepatch: Cleanup module page permission changes	2015-12-04 22:51:07 +01:00
locking	rtmutex: Make wait_lock irq safe	2016-01-26 11:08:35 +01:00
power	PM / sleep: Add support for read-only sysfs attributes	2016-01-04 22:28:59 +01:00
printk	kernel: printk: specify alignment for struct printk_log	2016-01-20 17:09:18 -08:00
rcu	Merge branches 'doc.2015.12.05a', 'exp.2015.12.07a', 'fixes.2015.12.07a', 'list.2015.12.04b' and 'torture.2015.12.05a' into HEAD	2015-12-07 17:02:54 -08:00
sched	wrappers for ->i_mutex access	2016-01-22 18:04:28 -05:00
time	Merge branch 'pm-cpuidle'	2016-01-21 00:43:21 +01:00
trace	Not much new with tracing for this release. Mostly just clean ups and	2016-01-12 20:04:15 -08:00
.gitignore
acct.c
async.c	async: export current_is_async()	2015-11-19 17:51:48 +01:00
audit_fsnotify.c	wrappers for ->i_mutex access	2016-01-22 18:04:28 -05:00
audit_tree.c
audit_watch.c	wrappers for ->i_mutex access	2016-01-22 18:04:28 -05:00
audit.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2016-01-17 19:13:15 -08:00
audit.h	security: Make inode argument of inode_getsecid non-const	2015-12-24 11:09:39 -05:00
auditfilter.c
auditsc.c	security: Make inode argument of inode_getsecid non-const	2015-12-24 11:09:39 -05:00
backtracetest.c
bounds.c
capability.c
cgroup_freezer.c	cgroup: kill cgrp_ss_priv[CGROUP_CANFORK_COUNT] and friends	2015-12-03 10:24:08 -05:00
cgroup_pids.c	cgroup_pids: fix a typo.	2015-12-14 14:54:37 -05:00
cgroup.c	Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2016-01-12 19:20:32 -08:00
compat.c
configs.c
context_tracking.c	context_tracking: Switch to new static_branch API	2015-11-24 09:56:43 +01:00
cpu_pm.c
cpu.c	kernel/cpu.c: make set_cpu_* static inlines	2016-01-20 17:09:18 -08:00
cpuset.c	Merge branch 'for-4.4-fixes' into for-4.5	2015-12-03 10:22:52 -05:00
crash_dump.c
cred.c	kmemcg: account certain kmem allocations to memcg	2016-01-14 16:00:49 -08:00
delayacct.c	kmemcg: account certain kmem allocations to memcg	2016-01-14 16:00:49 -08:00
dma.c
elfcore.c
exec_domain.c
exit.c	exit: remove unneeded declaration of exit_mm()	2016-01-20 17:09:18 -08:00
extable.c
fork.c	mm: rework virtual memory accounting	2016-01-14 16:00:49 -08:00
freezer.c
futex_compat.c	ptrace: use fsuid, fsgid, effective creds for fs access checks	2016-01-20 17:09:18 -08:00
futex.c	rtmutex: Make wait_lock irq safe	2016-01-26 11:08:35 +01:00
groups.c
hung_task.c
irq_work.c	treewide: Remove old email address	2015-11-23 09:44:58 +01:00
jump_label.c	treewide: Remove old email address	2015-11-23 09:44:58 +01:00
kallsyms.c
kcmp.c	ptrace: use fsuid, fsgid, effective creds for fs access checks	2016-01-20 17:09:18 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec_core.c	kernel/kexec_core.c: use list_for_each_entry_safe in kimage_free_page_list	2016-01-20 17:09:18 -08:00
kexec_file.c	kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE	2016-01-20 17:09:18 -08:00
kexec_internal.h	kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE	2016-01-20 17:09:18 -08:00
kexec.c	kexec: set KEXEC_TYPE_CRASH before sanity_check_segment_list()	2016-01-20 17:09:18 -08:00
kmod.c
kprobes.c
ksysfs.c	rcu: Remove TINY_RCU bloat from pointless boot parameters	2015-12-07 16:59:37 -08:00
kthread.c
latencytop.c
Makefile
membarrier.c
memremap.c	mm, x86: get_user_pages() for dax mappings	2016-01-15 17:56:32 -08:00
module_signing.c
module-internal.h
module.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching	2016-01-14 16:38:02 -08:00
notifier.c
nsproxy.c
padata.c
panic.c	printk: do cond_resched() between lines while outputting to consoles	2016-01-16 11:17:25 -08:00
params.c	Nothing exciting, minor tweaks and cleanups.	2015-11-09 15:53:39 -08:00
pid_namespace.c
pid.c	kmemcg: account certain kmem allocations to memcg	2016-01-14 16:00:49 -08:00
profile.c
ptrace.c	ptrace: use fsuid, fsgid, effective creds for fs access checks	2016-01-20 17:09:18 -08:00
range.c
reboot.c
relay.c	wrappers for ->i_mutex access	2016-01-22 18:04:28 -05:00
resource.c	restrict /dev/mem to idle io memory ranges	2016-01-09 06:30:49 -08:00
seccomp.c
signal.c	kernel/signal.c: unexport sigsuspend()	2015-11-20 16:17:32 -08:00
smp.c
smpboot.c
smpboot.h
softirq.c
stacktrace.c
stop_machine.c	kernel/stop_machine.c: remove CONFIG_SMP dependencies	2016-01-16 11:17:24 -08:00
sys_ni.c	vfs: add copy_file_range syscall and vfs helper	2015-12-01 14:00:53 -05:00
sys.c	prctl: take mmap sem for writing to protect against others	2016-01-20 17:09:18 -08:00
sysctl_binary.c
sysctl.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-01-22 10:24:03 -08:00
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
uid16.c
up.c
user_namespace.c	kernel/*: switch to memdup_user_nul()	2016-01-04 10:27:55 -05:00
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watchdog.c	Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq	2016-01-11 18:53:13 -08:00
workqueue_internal.h
workqueue.c	workqueue: simplify the apply_workqueue_attrs_locked()	2016-01-07 11:04:34 -05:00