Star64_linux/kernel
Frederic Weisbecker 90a340ed53 rcu: Exit RCU extended QS on kernel preemption after irq/exception
When an exception or an irq exits, and we are going to resume into
interrupted kernel code, the low level architecture code calls
preempt_schedule_irq() if there is a need to reschedule.

If the interrupt/exception occured between a call to rcu_user_enter()
(from syscall exit, exception exit, do_notify_resume exit, ...) and
a real resume to userspace (iret,...), preempt_schedule_irq() can be
called whereas RCU thinks we are in userspace. But preempt_schedule_irq()
is going to run kernel code and may be some RCU read side critical
section. We must exit the userspace extended quiescent state before
we call it.

To solve this, just call rcu_user_exit() in the beginning of
preempt_schedule_irq().

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2012-09-26 15:47:09 +02:00
..
debug kernel/debug: Make use of KGDB_REASON_NMI 2012-07-31 08:16:43 -05:00
events perf/hwpb: Invoke __perf_event_disable() if interrupts are already disabled 2012-09-04 17:29:53 +02:00
gcov
irq Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-08-03 10:56:44 -07:00
power Revert "NMI watchdog: fix for lockup detector breakage on resume" 2012-08-08 20:49:45 +02:00
sched rcu: Exit RCU extended QS on kernel preemption after irq/exception 2012-09-26 15:47:09 +02:00
time Merge remote-tracking branch 'tip/core/rcu' into next.2012.09.25b 2012-09-25 10:03:56 -07:00
trace tracing/syscalls: Fix perf syscall tracing when syscall_nr == -1 2012-08-17 15:19:46 -04:00
.gitignore
acct.c
async.c [SCSI] async: make async_synchronize_full() flush all work regardless of domain 2012-07-20 09:07:37 +01:00
audit.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
audit.h
audit_tree.c audit: clean up refcounting in audit-tree 2012-08-15 12:55:22 +02:00
audit_watch.c get rid of kern_path_parent() 2012-07-14 16:35:02 +04:00
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
cgroup.c Merge branch 'for-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2012-07-24 17:47:44 -07:00
cgroup_freezer.c
compat.c
configs.c
cpu.c smpboot: Provide infrastructure for percpu hotplug threads 2012-08-13 17:01:07 +02:00
cpu_pm.c
cpuset.c cpusets: Remove/update outdated comments 2012-07-24 13:53:28 +02:00
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c posix_types.h: Cleanup stale __NFDBITS and related definitions 2012-07-26 13:36:43 -07:00
extable.c
fork.c uprobes: Fix mmap_region()'s mm->mm_rb corruption if uprobe_mmap() fails 2012-08-21 11:48:12 +02:00
freezer.c
futex.c futex: Forbid uaddr == uaddr2 in futex_wait_requeue_pi() 2012-07-24 16:02:57 +02:00
futex_compat.c
groups.c
hrtimer.c hrtimer: Update hrtimer base offsets each hrtimer_interrupt 2012-07-11 23:34:39 +02:00
hung_task.c
irq_work.c
itimer.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c kdump: append newline to the last lien of vmcoreinfo note 2012-07-30 17:25:20 -07:00
kfifo.c
kmod.c kmod: avoid deadlock from recursive kmod call 2012-07-30 17:25:20 -07:00
kprobes.c
ksysfs.c
kthread.c kthread: Implement park/unpark facility 2012-08-13 17:01:06 +02:00
latencytop.c
lglock.c
lockdep.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
Makefile hotplug: Fix UP bug in smpboot hotplug code 2012-08-13 17:01:07 +02:00
module.c
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c
nsproxy.c
padata.c
panic.c panic: fix a possible deadlock in panic() 2012-07-30 17:25:13 -07:00
params.c
pid.c
pid_namespace.c pid-namespace: limit value of ns_last_pid to (0, max_pid) 2012-09-17 15:00:38 -07:00
posix-cpu-timers.c
posix-timers.c
printk.c printk: Fix calculation of length used to discard records 2012-08-12 21:25:50 +03:00
profile.c
ptrace.c
range.c
rcu.h
rcupdate.c rcu: Add PROVE_RCU_DELAY to provoke difficult races 2012-09-23 07:42:49 -07:00
rcutiny.c rcu: Move TINY_RCU quiescent state out of extended quiescent state 2012-09-23 07:42:52 -07:00
rcutiny_plugin.h rcu: Move TINY_PREEMPT_RCU away from raw_local_irq_save() 2012-09-23 07:42:51 -07:00
rcutorture.c rcu: Prevent initialization race in rcutorture kthreads 2012-09-23 07:42:23 -07:00
rcutree.c rcu: Switch task's syscall hooks on context switch 2012-09-26 15:47:02 +02:00
rcutree.h rcu: Ignore userspace extended quiescent state by default 2012-09-26 15:47:01 +02:00
rcutree_plugin.h rcu: Make RCU_FAST_NO_HZ handle adaptive ticks 2012-09-26 15:44:02 +02:00
rcutree_trace.c Merge remote-tracking branch 'tip/smp/hotplug' into next.2012.09.25b 2012-09-25 10:01:45 -07:00
relay.c
res_counter.c
resource.c resource: make sure requested range is included in the root range 2012-07-30 17:25:21 -07:00
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rtmutex_common.h
rwsem.c
seccomp.c
semaphore.c
signal.c signal: make sure we don't get stopped with pending task_work 2012-07-22 23:57:54 +04:00
smp.c
smpboot.c hotplug: Fix UP bug in smpboot hotplug code 2012-08-13 17:01:07 +02:00
smpboot.h smpboot: Provide infrastructure for percpu hotplug threads 2012-08-13 17:01:07 +02:00
softirq.c softirq: Use hotplug thread infrastructure 2012-08-13 17:01:07 +02:00
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys.c kernel/sys.c: avoid argv_free(NULL) 2012-07-30 17:25:13 -07:00
sys_ni.c
sysctl.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
sysctl_binary.c mm: prepare for removal of obsolete /proc/sys/vm/nr_pdflush_threads 2012-07-31 18:42:40 -07:00
task_work.c task_work: add a scheduling point in task_work_run() 2012-08-21 09:11:44 -07:00
taskstats.c taskstats: check nla_reserve() return 2012-07-30 17:25:21 -07:00
test_kprobes.c
time.c
timeconst.pl
timer.c alpha: take a bunch of syscalls into osf_sys.c 2012-08-19 08:41:19 -07:00
tracepoint.c
tsacct.c
uid16.c
up.c
user-return-notifier.c
user.c
user_namespace.c
utsname.c
utsname_sysctl.c
wait.c
watchdog.c watchdog: Use hotplug thread infrastructure 2012-08-13 17:01:07 +02:00
workqueue.c workqueue: reimplement work_on_cpu() using system_wq 2012-09-19 10:13:12 -07:00
workqueue_sched.h