linux-stable-rt/kernel
Nick Piggin 70ff05554f Fix PREEMPT_RCU without HOTPLUG_CPU
PREEMPT_RCU without HOTPLUG_CPU is broken.  The rcu_online_cpu is called
to initially populate rcu_cpu_online_map with all online CPUs when the
hotplug event handler is installed, and also to populate the map with
CPUs as they come online.  The former case is meant to happen with and
without HOTPLUG_CPU, but without HOTPLUG_CPU, the rcu_offline_cpu
function is no-oped -- while it still gets called, it does not set the
rcu CPU map.

With a blank RCU CPU map, grace periods get to tick by completely
oblivious to active RCU read side critical sections.  This results in
free-before-grace bugs.

Fix is obvious once the problem is known. (Also, change __devinit to
__cpuinit so the function gets thrown away on !HOTPLUG_CPU kernels).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Reported-and-tested-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ Nick is my personal hero of the day - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-10 11:13:44 -07:00
..
irq genirq: reenable a nobody cared disabled irq when a new driver arrives 2008-05-02 13:40:34 +02:00
power Merge branches 'release', 'acpica', 'bugzilla-10224', 'bugzilla-9772', 'bugzilla-9916', 'ec', 'eeepc', 'idle', 'misc', 'pm-legacy', 'sysfs-links-2.6.26', 'thermal', 'thinkpad' and 'video' into release 2008-04-30 13:58:00 -04:00
time clocksource: allow read access to available/current_clocksource 2008-05-03 18:11:48 +02:00
.gitignore
Kconfig.hz
Kconfig.preempt
Makefile sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK 2008-05-05 23:56:18 +02:00
acct.c
audit.c [PATCH] remove useless argument type in audit_filter_user() 2008-06-24 23:36:35 -04:00
audit.h
audit_tree.c [PATCH] list_for_each_rcu must die: audit 2008-05-17 03:30:23 -04:00
auditfilter.c [PATCH] remove useless argument type in audit_filter_user() 2008-06-24 23:36:35 -04:00
auditsc.c
backtracetest.c
bounds.c Add kbuild.h that contains common definitions for kbuild users 2008-04-29 08:06:29 -07:00
capability.c security: filesystem capabilities: fix fragile setuid fixup code 2008-07-04 10:40:08 -07:00
cgroup.c cgroups: remove node_ prefix_from ns subsystem 2008-05-24 09:56:14 -07:00
cgroup_debug.c CGroup API files: move "releasable" to cgroup_debug subsystem 2008-04-29 08:06:09 -07:00
compat.c ntp: support for TAI 2008-05-01 08:03:59 -07:00
configs.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
cpu.c kernel: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
cpuset.c Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-06-20 12:37:13 -07:00
delayacct.c
dma.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
exec_domain.c
exit.c signals: fix sigqueue_free() vs __exit_signal() race 2008-05-24 09:56:10 -07:00
extable.c
fork.c [PATCH] dup_fd() fixes, part 1 2008-05-16 17:22:26 -04:00
futex.c futexes: fix fault handling in futex_lock_pi 2008-06-23 13:31:15 +02:00
futex_compat.c
hrtimer.c hrtimer: prevent migration for raising softirq 2008-07-03 11:36:48 -07:00
itimer.c
kallsyms.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
kexec.c kexec: make extended crashkernel= syntax less confusing 2008-05-01 08:04:00 -07:00
kfifo.c
kgdb.c kgdb: sparse fix 2008-06-24 10:52:55 -05:00
kmod.c [PATCH] split linux/file.h 2008-05-01 13:08:16 -04:00
kprobes.c kernel/kprobes.c: Made kprobe_blacklist static. 2008-07-10 10:13:51 -07:00
ksysfs.c
kthread.c Deprecate find_task_by_pid() 2008-04-30 08:29:48 -07:00
latencytop.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
lockdep.c
lockdep_internals.h
lockdep_proc.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
marker.c make marker_debug static 2008-04-30 08:29:49 -07:00
module.c modules: proper cleanup of kobject without CONFIG_SYSFS 2008-05-23 13:09:33 +10:00
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c ipc: re-enable msgmni automatic recomputing msgmni if set to negative 2008-04-29 08:06:13 -07:00
ns_cgroup.c cgroups: kernel/ns_cgroup.c should #include <linux/nsproxy.h> 2008-04-29 08:06:07 -07:00
nsproxy.c ipc: sysvsem: refuse clone(CLONE_SYSVSEM|CLONE_NEWIPC) 2008-04-29 08:06:14 -07:00
panic.c Taint kernel after WARN_ON(condition) 2008-04-29 08:05:59 -07:00
params.c
pid.c pids: introduce change_pid() helper 2008-04-30 08:29:48 -07:00
pid_namespace.c pidns: make pid->level and pid_ns->level unsigned 2008-04-30 08:29:49 -07:00
pm_qos_params.c
posix-cpu-timers.c remove div_long_long_rem 2008-05-01 08:03:58 -07:00
posix-timers.c signals: join send_sigqueue() with send_group_sigqueue() 2008-04-30 08:29:36 -07:00
printk.c kernel/printk.c: Made printk_recursion_bug_msg static. 2008-07-08 18:10:34 -07:00
profile.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
ptrace.c make generic sys_ptrace unconditional 2008-05-01 10:21:54 -07:00
rcuclassic.c rcu: fix hotplug vs rcu race 2008-07-01 09:27:17 +02:00
rcupdate.c
rcupreempt.c Fix PREEMPT_RCU without HOTPLUG_CPU 2008-07-10 11:13:44 -07:00
rcupreempt_trace.c
rcutorture.c kernel: explicitly include required header files under kernel/ 2008-04-29 08:06:04 -07:00
relay.c splice: fix sendfile() issue with relay 2008-05-28 14:49:27 +02:00
res_counter.c memcgroup: add the max_usage member on the res_counter 2008-04-29 08:06:10 -07:00
resource.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rtmutex_common.h
rwsem.c
sched.c sched: fix divide error when trying to configure rt_period to zero 2008-07-01 08:23:24 +02:00
sched_clock.c sched: fix sched_clock_cpu() 2008-05-29 11:29:19 +02:00
sched_debug.c revert ("sched: fair-group: SMP-nice for group scheduling") 2008-05-29 11:28:57 +02:00
sched_fair.c sched: stop wake_affine from causing serious imbalance 2008-05-29 11:29:20 +02:00
sched_features.h
sched_idletask.c sched: make rt_sched_class, idle_sched_class static 2008-05-05 23:56:17 +02:00
sched_rt.c sched: rt: dont stop the period timer when there are tasks wanting to run 2008-06-20 11:00:19 +02:00
sched_stats.h sched, delay accounting: fix incorrect delay time when constantly waiting on runqueue 2008-06-19 14:15:28 +02:00
seccomp.c
semaphore.c Revert "semaphore: fix" 2008-05-10 20:43:22 -07:00
signal.c posix timers: discard SI_TIMER signals on exec 2008-05-26 10:37:07 -07:00
softirq.c Fix cpu hotplug problem in softirq code 2008-05-01 08:03:58 -07:00
softlockup.c softlockup: print a module list on being stuck 2008-07-05 08:51:24 +02:00
spinlock.c
srcu.c
stacktrace.c
stop_machine.c stop_machine: make stop_machine_run more virtualization friendly 2008-05-23 13:09:34 +10:00
sys.c sys_prctl(): fix return of uninitialized value 2008-05-24 09:56:13 -07:00
sys_ni.c
sysctl.c [PATCH] avoid multiplication overflows and signedness issues for max_fds 2008-05-16 17:22:52 -04:00
sysctl_check.c
taskstats.c Use find_task_by_vpid in taskstats 2008-04-30 08:29:48 -07:00
test_kprobes.c
time.c Make constants in kernel/timeconst.h fixed 64 bits 2008-05-02 16:18:42 -07:00
timeconst.pl Make constants in kernel/timeconst.h fixed 64 bits 2008-05-02 16:18:42 -07:00
timer.c debugobjects: add timer specific object debugging code 2008-04-30 08:29:53 -07:00
tsacct.c
uid16.c
user.c alloc_uid: cleanup 2008-04-30 08:29:53 -07:00
user_namespace.c eCryptfs: make key module subsystem respect namespaces 2008-04-29 08:06:07 -07:00
utsname.c kernel: explicitly include required header files under kernel/ 2008-04-29 08:06:04 -07:00
utsname_sysctl.c
wait.c
workqueue.c Christoph has moved 2008-07-04 10:40:04 -07:00