aha/kernel
Paul Menage 8f3ff20862 cgroups: revert "cgroups: fix pid namespace bug"
The following series adds a "cgroup.procs" file to each cgroup that
reports unique tgids rather than pids, and allows all threads in a
threadgroup to be atomically moved to a new cgroup.

The subsystem "attach" interface is modified to support attaching whole
threadgroups at a time, which could introduce potential problems if any
subsystem were to need to access the old cgroup of every thread being
moved.  The attach interface may need to be revised if this becomes the
case.

Also added is functionality for read/write locking all CLONE_THREAD
fork()ing within a threadgroup, by means of an rwsem that lives in the
sighand_struct, for per-threadgroup-ness and also for sharing a cacheline
with the sighand's atomic count.  This scheme should introduce no extra
overhead in the fork path when there's no contention.

The final patch reveals potential for a race when forking before a
subsystem's attach function is called - one potential solution in case any
subsystem has this problem is to hang on to the group's fork mutex through
the attach() calls, though no subsystem yet demonstrates need for an
extended critical section.

This patch:

Revert

commit 096b7fe012
Author:     Li Zefan <lizf@cn.fujitsu.com>
AuthorDate: Wed Jul 29 15:04:04 2009 -0700
Commit:     Linus Torvalds <torvalds@linux-foundation.org>
CommitDate: Wed Jul 29 19:10:35 2009 -0700

    cgroups: fix pid namespace bug

This is in preparation for some clashing cgroups changes that subsume the
original commit's functionaliy.

The original commit fixed a pid namespace bug which Ben Blum fixed
independently (in the same way, but with different code) as part of a
series of patches.  I played around with trying to reconcile Ben's patch
series with Li's patch, but concluded that it was simpler to just revert
Li's, given that Ben's patch series contained essentially the same fix.

Signed-off-by: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24 07:20:58 -07:00
..
gcov powerpc: Enable GCOV 2009-08-20 10:29:28 +10:00
irq Merge branch 'irq-threaded-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-11 13:21:31 -07:00
power headers: utsname.h redux 2009-09-23 18:13:10 -07:00
time time: add function to convert between calendar time and broken-down time for universal use 2009-09-24 07:20:56 -07:00
trace cpumask: use zalloc_cpumask_var() where possible 2009-09-24 09:34:24 +09:30
.gitignore
acct.c bsdacct: switch credentials for writing to the accounting file 2009-08-24 11:33:40 +10:00
async.c async: Fix lack of boot-time console due to insufficient synchronization 2009-06-08 12:31:53 -07:00
audit.c Fix rule eviction order for AUDIT_DIR 2009-06-24 00:02:38 -04:00
audit.h Fix rule eviction order for AUDIT_DIR 2009-06-24 00:02:38 -04:00
audit_tree.c Fix rule eviction order for AUDIT_DIR 2009-06-24 00:02:38 -04:00
audit_watch.c Audit: clean up all op= output to include string quoting 2009-06-24 00:00:52 -04:00
auditfilter.c Audit: clean up all op= output to include string quoting 2009-06-24 00:00:52 -04:00
auditsc.c Fix rule eviction order for AUDIT_DIR 2009-06-24 00:02:38 -04:00
backtracetest.c
bounds.c
capability.c
cgroup.c cgroups: revert "cgroups: fix pid namespace bug" 2009-09-24 07:20:58 -07:00
cgroup_freezer.c
compat.c signals: implement sys_rt_tgsigqueueinfo 2009-04-30 19:24:24 +02:00
configs.c
cpu.c Merge branch 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-15 09:19:38 -07:00
cpuset.c cpuset,mm: update tasks' mems_allowed in time 2009-06-16 19:47:31 -07:00
cred-internals.h
cred.c creds_are_invalid() needs to be exported for use by modules: 2009-09-23 11:02:26 -07:00
delayacct.c headers: taskstats_kern.h trim 2009-09-18 09:48:52 -07:00
dma.c
exec_domain.c Get rid of indirect include of fs_struct.h 2009-03-31 23:00:27 -04:00
exit.c getrusage: fill ru_maxrss value 2009-09-23 07:39:30 -07:00
extable.c Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
fork.c Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-23 09:46:15 -07:00
freezer.c sched: fix nr_uninterruptible accounting of frozen tasks really 2009-07-18 14:19:53 +02:00
futex.c Merge branch 'core-futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-11 13:16:22 -07:00
futex_compat.c futex: Fix compat_futex to be same as futex for REQUEUE_PI 2009-08-10 15:41:12 +02:00
groups.c groups: move code to kernel/groups.c 2009-06-16 19:47:48 -07:00
hrtimer.c Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-23 09:46:15 -07:00
hung_task.c
itimer.c itimers: Add tracepoints for itimer 2009-08-29 14:10:07 +02:00
kallsyms.c kallsyms: use new arch_is_kernel_text() 2009-09-23 07:39:30 -07:00
Kconfig.freezer
Kconfig.hz
Kconfig.preempt
kexec.c kexec: fix omitting offset in extended crashkernel syntax 2009-07-29 19:10:34 -07:00
kfifo.c kfifo: Use "const" definitions 2009-09-19 13:13:17 -07:00
kgdb.c sysrq, intel_fb: fix sysrq g collision 2009-05-15 07:56:24 -05:00
kmod.c Revert "kmod: fix race in usermodehelper code" 2009-09-23 18:12:10 -07:00
kprobes.c seq_file: constify seq_operations 2009-09-23 07:39:29 -07:00
ksysfs.c
kthread.c sched: Keep kthreads at default priority 2009-09-09 17:30:06 +02:00
latencytop.c
lockdep.c lockdep: use new arch_is_kernel_data() 2009-09-23 07:39:30 -07:00
lockdep_internals.h lockdep: BFS cleanup 2009-07-24 10:53:29 +02:00
lockdep_proc.c seq_file: constify seq_operations 2009-09-23 07:39:29 -07:00
lockdep_states.h
Makefile cgroups: move the cgroup debug subsys into cgroup.c to access internal state 2009-09-24 07:20:57 -07:00
module.c nommu: add support for Memory Protection Units (MPU) 2009-09-22 07:17:43 -07:00
mutex-debug.c
mutex-debug.h
mutex.c Merge branch 'linus' into perfcounters/core 2009-06-11 17:55:42 +02:00
mutex.h
notifier.c
ns_cgroup.c cgroups: relax ns_can_attach checks to allow attaching to grandchild cgroups 2009-04-02 19:04:53 -07:00
nsproxy.c nsproxy: extract create_nsproxy() 2009-06-18 13:03:56 -07:00
panic.c trivial: Correct print_tainted routine name in comment 2009-09-21 15:14:53 +02:00
params.c module_param: allow 'bool' module_params to be bool, not just int. 2009-06-12 21:46:58 +09:30
perf_event.c perf: Tidy up after the big rename 2009-09-21 14:34:11 +02:00
pid.c mm: also use alloc_large_system_hash() for the PID hash table 2009-09-22 07:17:38 -07:00
pid_namespace.c pidns: rewrite copy_pid_ns() 2009-06-18 13:03:55 -07:00
pm_qos_params.c
posix-cpu-timers.c itimers: Add tracepoints for itimer 2009-08-29 14:10:07 +02:00
posix-timers.c time: Introduce CLOCK_REALTIME_COARSE 2009-08-21 21:43:46 +02:00
printk.c printk: add printk_delay to make messages readable for some scenarios 2009-09-23 07:39:28 -07:00
profile.c kernel/profile.c: Switch /proc/irq/prof_cpu_mask to seq_file 2009-09-20 20:15:40 +02:00
ptrace.c Merge branch 'master' into next 2009-07-14 00:30:40 +10:00
rcupdate.c rcu: Fix whitespace inconsistencies 2009-09-19 08:53:22 +02:00
rcutorture.c rcu: Fix whitespace inconsistencies 2009-09-19 08:53:22 +02:00
rcutree.c rcu: Fix whitespace inconsistencies 2009-09-19 08:53:22 +02:00
rcutree.h rcu: Fix whitespace inconsistencies 2009-09-19 08:53:22 +02:00
rcutree_plugin.h rcu: Fix whitespace inconsistencies 2009-09-19 08:53:22 +02:00
rcutree_trace.c rcu: Fix whitespace inconsistencies 2009-09-19 08:53:22 +02:00
relay.c Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
res_counter.c memcg: add interface to reset limits 2009-06-18 13:03:48 -07:00
resource.c walk system ram range 2009-09-23 07:39:41 -07:00
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c rtmutex: Avoid deadlock in rt_mutex_start_proxy_lock() 2009-08-06 05:50:21 +02:00
rtmutex.h
rtmutex_common.h rt_mutex: add proxy lock routines 2009-04-06 11:14:02 +02:00
rwsem.c
sched.c Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-23 09:46:15 -07:00
sched_clock.c sched_clock: Make it NMI safe 2009-09-18 20:47:30 +02:00
sched_cpupri.c sched: Add new prio to cpupri before removing old prio 2009-08-02 14:26:09 +02:00
sched_cpupri.h cpumask: remove cpumask_t from core 2009-03-30 22:05:17 +10:30
sched_debug.c sched: Add new wakeup preemption mode: WAKEUP_RUNNING 2009-09-17 10:17:25 +02:00
sched_fair.c Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-21 09:06:17 -07:00
sched_features.h sched: Add new wakeup preemption mode: WAKEUP_RUNNING 2009-09-17 10:17:25 +02:00
sched_idletask.c sched: Simplify sys_sched_rr_get_interval() system call 2009-09-21 09:53:55 +02:00
sched_rt.c sched: Simplify sys_sched_rr_get_interval() system call 2009-09-21 09:53:55 +02:00
sched_stats.h sched: remove unused fields from struct rq 2009-03-24 23:16:51 +01:00
seccomp.c x86-64: seccomp: fix 32/64 syscall hole 2009-03-02 15:41:30 -08:00
semaphore.c
signal.c do_sigaltstack: small cleanups 2009-08-01 11:18:56 -07:00
slow-work.c slow-work: use round_jiffies() for thread pool's cull and OOM timers 2009-06-16 19:47:49 -07:00
smp.c cpumask: remove arch_send_call_function_ipi 2009-09-24 09:34:47 +09:30
softirq.c softirq: add BLOCK_IOPOLL to softirq_to_name 2009-09-17 15:53:44 -04:00
softlockup.c
spinlock.c locking: Allow arch-inlined spinlocks 2009-08-31 18:08:50 +02:00
srcu.c
stacktrace.c
stop_machine.c cpumask: remove cpumask_t from core 2009-03-30 22:05:17 +10:30
sys.c getrusage: fill ru_maxrss value 2009-09-23 07:39:30 -07:00
sys_ni.c perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
sysctl.c headers: utsname.h redux 2009-09-23 18:13:10 -07:00
sysctl_check.c
taskstats.c genetlink: make netns aware 2009-07-12 14:03:27 -07:00
test_kprobes.c
time.c time: Prevent 32 bit overflow with set_normalized_timespec() 2009-09-15 10:17:30 +02:00
timeconst.pl
timer.c Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-23 09:46:15 -07:00
tracepoint.c trivial: fix typo "to to" in multiple files 2009-09-21 15:14:55 +02:00
tsacct.c Fix fixpoint divide exception in acct_update_integrals 2009-03-09 08:13:35 -07:00
uid16.c headers: utsname.h redux 2009-09-23 18:13:10 -07:00
up.c
user.c sched: delayed cleanup of user_struct 2009-06-15 21:30:23 -07:00
user_namespace.c Fix recursive lock in free_uid()/free_user_ns() 2009-02-27 16:26:21 -08:00
utsname.c utsns: extract creeate_uts_ns() 2009-06-18 13:03:55 -07:00
utsname_sysctl.c proc_sysctl: use CONFIG_PROC_SYSCTL around ipc and utsname proc_handlers 2009-04-02 19:05:01 -07:00
wait.c locking, sched: Give waitqueue spinlocks their own lockdep classes 2009-08-10 14:43:09 +02:00
workqueue.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-11 13:23:18 -07:00