Frederic Weisbecker d65ec12127 context_tracking: Fix runtime CPU off-case ... As long as the context tracking is enabled on any CPU, even a single one, all other CPUs need to keep track of their user <-> kernel boundaries cross as well. This is because a task can sleep while servicing an exception that happened in the kernel or in userspace. Then when the task eventually wakes up and return from the exception, the CPU needs to know if we resume in userspace or in the kernel. exception_exit() get this information from exception_enter() that saved the previous state. If the CPU where the exception happened didn't keep track of these informations, exception_exit() doesn't know which state tracking to restore on the CPU where the task got migrated and we may return to userspace with the context tracking subsystem thinking that we are in kernel mode. This can be fixed in the long term if we move our context tracking probes on very low level arch fast path user <-> kernel boundary, although even that is worrisome as an exception can still happen in the few instructions between the probe and the actual iret. Also we are not yet ready to set these probes in the fast path given the potential overhead problem it induces. So let's fix this by always enable context tracking even on CPUs that are not in the full dynticks range. OTOH we can spare the rcu_user_*() and vtime_user_*() calls there because the tick runs on these CPUs and we can handle RCU state machine and cputime accounting through it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Kevin Hilman <khilman@linaro.org>		2013-08-13 00:40:44 +02:00
..
cpu	idle: Enable interrupts in the weak arch_cpu_idle() implementation	2013-06-14 23:01:05 +02:00
debug	kgdb/sysrq: fix inconstistent help message of sysrq key	2013-04-30 17:04:10 -07:00
events	Driver core patches for 3.11-rc2	2013-07-18 12:48:40 -07:00
gcov	kernel/gcov: remove depends on CONFIG_EXPERIMENTAL	2013-01-11 11:39:33 -08:00
irq	Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-07-13 15:37:30 -07:00
power	PM / Sleep: avoid 'autosleep' in shutdown progress	2013-07-15 01:31:37 +02:00
sched	vtime: Update a few comments	2013-08-13 00:40:44 +02:00
time	Merge branch 'fortglx/3.11/time' of git://git.linaro.org/people/jstultz/linux into timers/urgent	2013-08-12 18:08:23 +02:00
trace	tracing: Kill the unbalanced tr->ref++ in tracing_buffers_open()	2013-07-19 14:32:22 -04:00
.gitignore	kernel/hz.bc: ignore.	2013-04-22 07:09:06 -07:00
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	locking: Fix copy/paste errors of "ARCH_INLINE_*_UNLOCK_BH"	2013-05-28 08:50:00 +02:00
Kconfig.preempt	…
Makefile	reboot: move shutdown/reboot related functions to kernel/reboot.c	2013-07-09 10:33:29 -07:00
acct.c	fs: Fix hang with BSD accounting on frozen filesystem	2013-05-04 14:57:58 -04:00
async.c	async: rename and redefine async_func_ptr	2013-03-12 13:59:14 -07:00
audit.c	audit: wait_for_auditd() should use TASK_UNINTERRUPTIBLE	2013-06-12 16:29:45 -07:00
audit.h	audit: fix mq_open and mq_unlink to add the MQ root as a hidden parent audit_names record	2013-07-09 10:33:19 -07:00
audit_tree.c	kernel/audit_tree.c:audit_add_tree_rule(): protect `rule' from kill_rules()	2013-06-12 16:29:46 -07:00
audit_watch.c	audit: catch possible NULL audit buffers	2013-01-11 14:54:55 -08:00
auditfilter.c	audit: Fix decimal constant description	2013-07-09 10:33:19 -07:00
auditsc.c	audit: fix mq_open and mq_unlink to add the MQ root as a hidden parent audit_names record	2013-07-09 10:33:19 -07:00
backtracetest.c	…
bounds.c	…
capability.c	Add file_ns_capable() helper function for open-time capability checking	2013-04-14 10:06:31 -07:00
cgroup.c	cgroup: we can use simple_lookup() now	2013-07-14 17:50:23 +04:00
cgroup_freezer.c	cgroup: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free()	2012-11-19 08:13:38 -08:00
compat.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal	2013-05-01 07:21:43 -07:00
configs.c	proc: Supply PDE attribute setting accessor functions	2013-05-01 17:29:18 -04:00
context_tracking.c	context_tracking: Fix runtime CPU off-case	2013-08-13 00:40:44 +02:00
cpu.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
cpu_pm.c	…
cpuset.c	Merge branch 'for-3.11-cpuset' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2013-07-02 20:04:25 -07:00
crash_dump.c	…
cred.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2012-12-18 10:55:28 -08:00
delayacct.c	cputime: Use accessors to read task cputime stats	2013-01-27 19:23:31 +01:00
dma.c	…
elfcore.c	…
exec_domain.c	…
exit.c	ptrace: revert "Prepare to fix racy accesses on task breakpoints"	2013-07-09 10:33:26 -07:00
extable.c	extable: Flip the sorting message	2013-04-15 13:25:16 +02:00
fork.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
freezer.c	freezer: skip waking up tasks with PF_FREEZER_SKIP set	2013-05-12 14:16:22 +02:00
futex.c	futex: Use freezable blocking call	2013-06-25 23:11:19 +02:00
futex_compat.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal	2013-02-23 18:50:11 -08:00
groups.c	…
hrtimer.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
hung_task.c	…
irq_work.c	Merge branch 'nohz/printk-v8' into irq/core	2013-02-05 00:48:46 +01:00
itimer.c	…
jump_label.c	…
kallsyms.c	kernel: kallsyms: memory override issue, need check destination buffer length	2013-04-15 15:17:26 +09:30
kcmp.c	kcmp: include linux/ptrace.h	2012-12-20 17:40:19 -08:00
kexec.c	kexec: Use min() and min_t() to simplify logic	2013-04-30 17:04:07 -07:00
kmod.c	usermodehelper: kill the sub_info->path[0] check	2013-07-03 16:08:02 -07:00
kprobes.c	kprobes: handle empty/invalid input to debugfs "enabled" file	2013-07-03 16:07:46 -07:00
ksysfs.c	Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2012-12-11 18:10:49 -08:00
kthread.c	kthread: implement probe_kthread_data()	2013-04-30 17:04:02 -07:00
latencytop.c	…
lglock.c	…
lockdep.c	lockdep: remove task argument from debug_check_no_locks_held	2013-05-12 14:16:21 +02:00
lockdep_internals.h	…
lockdep_proc.c	lockdep: Use KSYM_NAME_LEN'ed buffer for __get_key_name()	2012-10-24 12:39:09 +02:00
lockdep_states.h	…
modsign_certificate.S	CONFIG_SYMBOL_PREFIX: cleanup.	2013-03-15 15:09:43 +10:30
modsign_pubkey.c	keys: use keyring_alloc() to create module signing keyring	2012-12-20 17:40:21 -08:00
module-internal.h	MODSIGN: Move the magic string to the end of a module and eliminate the search	2012-10-19 17:30:40 -07:00
module.c	Nothing interesting. Except the most embarrassing bugfix ever. But let's	2013-07-10 14:51:41 -07:00
module_signing.c	MODSIGN: Don't use enum-type bitfields in module signature info block	2012-12-05 11:27:24 +10:30
mutex-debug.c	…
mutex-debug.h	…
mutex.c	mutex: Move ww_mutex definitions to ww_mutex.h	2013-07-12 12:07:46 +02:00
mutex.h	…
notifier.c	…
nsproxy.c	proc: Split the namespace stuff out into linux/proc_ns.h	2013-05-01 17:29:39 -04:00
padata.c	padata: use __this_cpu_read per-cpu helper	2012-12-06 17:16:23 +08:00
panic.c	The majority of the changes here are cleanups for the large changes that	2013-07-11 09:02:09 -07:00
params.c	There is no /sys/parameters	2013-07-02 15:38:19 +09:30
pid.c	kernel/pid.c: move statement	2013-07-03 16:08:05 -07:00
pid_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
posix-cpu-timers.c	posix_timers: fix racy timer delta caching on task exit	2013-07-03 16:54:42 +02:00
posix-timers.c	posix-timers: Remove unused variable	2013-04-18 12:51:19 +02:00
printk.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
profile.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
ptrace.c	ptrace: PTRACE_DETACH should do flush_ptrace_hw_breakpoint(child)	2013-07-09 10:33:26 -07:00
range.c	range: Do not add new blank slot with add_range_with_merge	2013-06-18 11:32:10 -05:00
rcu.h	rcu: Provide RCU CPU stall warnings for tiny RCU	2013-01-28 22:06:21 -08:00
rcupdate.c	Merge branches 'cbnum.2013.06.10a', 'doc.2013.06.10a', 'fixes.2013.06.10a', 'srcu.2013.06.10a' and 'tiny.2013.06.10a' into HEAD	2013-06-10 13:46:44 -07:00
rcutiny.c	rcu: Shrink TINY_RCU by reworking CPU-stall ifdefs	2013-06-10 13:45:53 -07:00
rcutiny_plugin.h	rcu: Shrink TINY_RCU by reworking CPU-stall ifdefs	2013-06-10 13:45:53 -07:00
rcutorture.c	rcu: delete __cpuinit usage from all rcu files	2013-07-14 19:36:58 -04:00
rcutree.c	rcu: delete __cpuinit usage from all rcu files	2013-07-14 19:36:58 -04:00
rcutree.h	rcu: delete __cpuinit usage from all rcu files	2013-07-14 19:36:58 -04:00
rcutree_plugin.h	rcu: delete __cpuinit usage from all rcu files	2013-07-14 19:36:58 -04:00
rcutree_trace.c	rcutrace: single_open() leaks	2013-05-05 00:16:35 -04:00
reboot.c	reboot: move arch/x86 reboot= handling to generic kernel	2013-07-09 10:33:29 -07:00
relay.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
res_counter.c	res_counter: return amount of charges after res_counter_uncharge()	2012-12-18 15:02:12 -08:00
resource.c	kernel/resource.c: remove the unneeded assignment in function __find_resource	2013-07-03 16:08:06 -07:00
rtmutex-debug.c	sched/rt: Move rt specific bits into new header file	2013-02-07 20:51:08 +01:00
rtmutex-debug.h	…
rtmutex-tester.c	locking/rtmutex/tester: Set correct permissions on sysfs files	2013-04-10 14:48:37 +02:00
rtmutex.c	rtmutex: Document rt_mutex_adjust_prio_chain()	2013-05-28 09:23:52 +02:00
rtmutex.h	…
rtmutex_common.h	…
rwsem.c	Revert "rw_semaphore: remove up/down_read_non_owner"	2013-03-23 15:53:52 -07:00
seccomp.c	seccomp: allow BPF_XOR based ALU instructions.	2013-03-26 11:07:19 +11:00
semaphore.c	semaphore: use `bool' type for semaphore_waiter's up	2013-04-30 17:04:08 -07:00
signal.c	sigtimedwait: use freezable blocking call	2013-05-12 14:16:23 +02:00
smp.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
smpboot.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
smpboot.h	…
softirq.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
spinlock.c	…
srcu.c	srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock()	2013-02-07 15:19:36 -08:00
stacktrace.c	…
stop_machine.c	stop_machine: Mark per cpu stopper enabled early	2013-02-26 22:25:17 +01:00
sys.c	reboot: move shutdown/reboot related functions to kernel/reboot.c	2013-07-09 10:33:29 -07:00
sys_ni.c	unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE	2013-05-09 13:46:38 -04:00
sysctl.c	Merge branch 'linus' into timers/urgent	2013-07-12 12:34:42 +02:00
sysctl_binary.c	kernel: remove unnecessary head file	2013-06-26 18:01:46 +09:00
task_work.c	…
taskstats.c	taskstats: cgroupstats_user_cmd() may leak on error	2012-10-06 03:05:31 +09:00
test_kprobes.c	kernel/: rename random32() to prandom_u32()	2013-04-29 18:28:42 -07:00
time.c	sched: Rename sched.c as sched/core.c in comments and Documentation	2013-06-19 12:58:42 +02:00
timeconst.bc	kernel: Replace timeconst.pl with a bc script	2013-02-16 23:17:25 +01:00
timer.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
tracepoint.c	Tracing updates for Linux 3.10	2013-04-29 13:55:38 -07:00
tsacct.c	cputime: Use accessors to read task cputime stats	2013-01-27 19:23:31 +01:00
uid16.c	make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect	2013-03-03 22:58:33 -05:00
up.c	…
user-return-notifier.c	hlist: drop the node parameter from iterators	2013-02-27 19:10:24 -08:00
user.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
user_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
utsname.c	proc: Split the namespace stuff out into linux/proc_ns.h	2013-05-01 17:29:39 -04:00
utsname_sysctl.c	kernel/utsname_sysctl.c: put get/get_uts() into CONFIG_PROC_SYSCTL code block	2013-02-27 19:10:22 -08:00
wait.c	Add wait_on_atomic_t() and wake_up_atomic_t()	2013-05-15 13:50:38 +01:00
watchdog.c	watchdog: Boot-disable by default on full dynticks	2013-06-20 15:46:32 +02:00
workqueue.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
workqueue_internal.h	sched: Rename sched.c as sched/core.c in comments and Documentation	2013-06-19 12:58:42 +02:00