tmp_suning_uos_patched/kernel
Paul Menage 307257cf47 cgroups: fix a race between rmdir and remount
When a cgroup is removed, it's unlinked from its parent's children list,
but not actually freed until the last dentry on it is released (at which
point cgrp->root->number_of_cgroups is decremented).

Currently rebind_subsystems checks for the top cgroup's child list being
empty in order to rebind subsystems into or out of a hierarchy - this can
result in the set of subsystems bound to a hierarchy being
removed-but-not-freed cgroup.

The simplest fix for this is to forbid remounts that change the set of
subsystems on a hierarchy that has removed-but-not-freed cgroups.  This
bug can be reproduced via:

mkdir /mnt/cg
mount -t cgroup -o ns,freezer cgroup /mnt/cg
mkdir /mnt/cg/foo
sleep 1h < /mnt/cg/foo &
rmdir /mnt/cg/foo
mount -t cgroup -o remount,ns,devices,freezer cgroup /mnt/cg
kill $!

Though the above will cause oops in -mm only but not mainline, but the bug
can cause memory leak in mainline (and even oops)

Signed-off-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-15 16:27:07 -08:00
..
irq
power
time
trace
.gitignore
acct.c
audit_tree.c
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
cgroup_debug.c
cgroup_freezer.c
cgroup.c cgroups: fix a race between rmdir and remount 2008-12-15 16:27:07 -08:00
compat.c
configs.c
cpu.c
cpuset.c
delayacct.c
dma-coherent.c
dma.c
exec_domain.c
exit.c
extable.c
fork.c fix mapping_writably_mapped() 2008-12-10 14:40:45 -08:00
freezer.c
futex_compat.c
futex.c
hrtimer.c
itimer.c
kallsyms.c
Kconfig.freezer
Kconfig.hz
Kconfig.preempt
kexec.c
kfifo.c
kgdb.c
kmod.c
kprobes.c
ksysfs.c
kthread.c
latencytop.c KSYM_SYMBOL_LEN fixes 2008-12-10 08:01:54 -08:00
lockdep_internals.h
lockdep_proc.c
lockdep.c
Makefile
marker.c
module.c
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c
ns_cgroup.c
nsproxy.c
panic.c
params.c
pid_namespace.c
pid.c
pm_qos_params.c
posix-cpu-timers.c
posix-timers.c
printk.c
profile.c
ptrace.c
rcuclassic.c
rcupdate.c
rcupreempt_trace.c
rcupreempt.c
rcutorture.c
relay.c
res_counter.c
resource.c
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_clock.c Revert "sched_clock: prevent scd->clock from moving backwards" 2008-12-14 16:23:17 -08:00
sched_cpupri.c
sched_cpupri.h
sched_debug.c
sched_fair.c
sched_features.h
sched_idletask.c
sched_rt.c
sched_stats.h
sched.c
seccomp.c
semaphore.c
signal.c
smp.c
softirq.c
softlockup.c
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c
sysctl_check.c
sysctl.c
taskstats.c
test_kprobes.c
time.c
timeconst.pl
timer.c
tracepoint.c
tsacct.c
uid16.c
user_namespace.c
user.c
utsname_sysctl.c
utsname.c
wait.c
workqueue.c