linux/kernel
Aleksa Sarai 49b786ea14 cgroup: implement the PIDs subsystem
Adds a new single-purpose PIDs subsystem to limit the number of
tasks that can be forked inside a cgroup. Essentially this is an
implementation of RLIMIT_NPROC that applies to a cgroup rather than a
process tree.

However, it should be noted that organisational operations (adding and
removing tasks from a PIDs hierarchy) will *not* be prevented. Rather,
the number of tasks in the hierarchy cannot exceed the limit through
forking. This is due to the fact that, in the unified hierarchy, attach
cannot fail (and it is not possible for a task to overcome its PIDs
cgroup policy limit by attaching to a child cgroup -- even if migrating
mid-fork it must be able to fork in the parent first).

PIDs are fundamentally a global resource, and it is possible to reach
PID exhaustion inside a cgroup without hitting any reasonable kmemcg
policy. Once you've hit PID exhaustion, you're only in a marginally
better state than OOM. This subsystem allows PID exhaustion inside a
cgroup to be prevented.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-07-14 17:29:23 -04:00
..
bpf bpf: allow networking programs to use bpf_trace_printk() for debugging 2015-06-15 15:53:50 -07:00
configs kconfig: add xenconfig defconfig helper 2015-06-16 11:04:29 +01:00
debug debug: prevent entering debug mode on panic/exception. 2015-02-19 12:39:03 -06:00
events Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-07-04 19:36:06 -07:00
gcov gcov: add support for GCC 5.1 2015-06-30 19:44:57 -07:00
irq Merge branch 'irq/for-x86' into irq/core 2015-06-20 19:14:31 +02:00
livepatch Merge branches 'for-4.1/upstream-fixes', 'for-4.2/kaslr' and 'for-4.2/upstream' into for-linus 2015-06-22 16:26:56 +02:00
locking Merge branch 'sched-hrtimers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-06-24 15:09:40 -07:00
power Power management and ACPI fixes for v4.2-rc1 2015-07-01 14:17:44 -07:00
printk printk: improve the description of /dev/kmsg line format 2015-06-30 19:44:59 -07:00
rcu This patch series contains several clean ups and even a new trace clock 2015-06-26 14:02:43 -07:00
sched cgroup: allow a cgroup subsystem to reject a fork 2015-07-14 17:29:23 -04:00
time Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-07-01 15:44:18 -07:00
trace This patch series contains several clean ups and even a new trace clock 2015-06-26 14:02:43 -07:00
.gitignore
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/qrwlock: Rename QUEUE_RWLOCK to QUEUED_RWLOCKS 2015-05-12 09:46:00 +02:00
Kconfig.preempt
Makefile cgroup: implement the PIDs subsystem 2015-07-14 17:29:23 -04:00
acct.c acct: check FMODE_CAN_WRITE 2015-04-11 22:27:55 -04:00
async.c
audit.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-06-27 13:53:16 -07:00
audit.h Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-04-22 14:49:23 -07:00
audit_tree.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
audit_watch.c VFS: audit: d_backing_inode() annotations 2015-04-15 15:06:55 -04:00
auditfilter.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-02-11 20:07:47 -08:00
auditsc.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-06-27 13:53:16 -07:00
backtracetest.c
bounds.c
capability.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
cgroup.c cgroup: allow a cgroup subsystem to reject a fork 2015-07-14 17:29:23 -04:00
cgroup_freezer.c cgroup: allow a cgroup subsystem to reject a fork 2015-07-14 17:29:23 -04:00
cgroup_pids.c cgroup: implement the PIDs subsystem 2015-07-14 17:29:23 -04:00
compat.c compat: cleanup coding in compat_get_bitmap() and compat_put_bitmap() 2015-06-04 23:57:18 +02:00
configs.c
context_tracking.c context_tracking: Inherit TIF_NOHZ through forks instead of context switches 2015-05-07 12:02:51 +02:00
cpu.c cpu: Remove new instance of __cpuinit that crept back in 2015-05-27 12:58:39 -07:00
cpu_pm.c
cpuset.c kernel, cpuset: remove exception for __GFP_THISNODE 2015-04-14 16:49:03 -07:00
crash_dump.c
cred.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
delayacct.c
dma.c
elfcore.c
exec_domain.c Remove rest of exec domains. 2015-04-12 21:03:31 +02:00
exit.c exit,stats: /* obey this comment */ 2015-06-25 17:00:43 -07:00
extable.c ftrace/x86/extable: Add is_ftrace_trampoline() function 2014-11-19 15:25:26 -05:00
fork.c cgroup: allow a cgroup subsystem to reject a fork 2015-07-14 17:29:23 -04:00
freezer.c
futex.c Merge branch 'sched-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-06-24 14:46:01 -07:00
futex_compat.c
groups.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
hung_task.c kernel/hung_task.c: change hung_task.c to use for_each_process_thread() 2015-04-15 16:35:22 -07:00
irq_work.c
jump_label.c module, jump_label: Fix module locking 2015-05-27 11:09:50 +09:30
kallsyms.c
kcmp.c
kexec.c kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path 2015-06-30 19:44:57 -07:00
kmod.c usermodehelper: kill the kmod_thread_locker logic 2014-12-10 17:41:17 -08:00
kprobes.c kprobes: makes kprobes/enabled works correctly for optimized kprobes. 2015-02-13 21:21:42 -08:00
ksysfs.c
kthread.c
latencytop.c
module-internal.h
module.c Minor merge needed, due to function move. 2015-07-01 10:49:25 -07:00
module_signing.c
notifier.c rcu: Make SRCU optional by using CONFIG_SRCU 2015-01-06 11:04:29 -08:00
nsproxy.c bury struct proc_ns in fs/proc 2014-12-04 14:34:54 -05:00
padata.c padata: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:38 -08:00
panic.c kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path 2015-06-30 19:44:57 -07:00
params.c Minor merge needed, due to function move. 2015-07-01 10:49:25 -07:00
pid.c fork: report pid reservation failure properly 2015-04-17 09:04:06 -04:00
pid_namespace.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-12-16 15:53:03 -08:00
profile.c profile: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:38 -08:00
ptrace.c ptrace: ptrace_detach() can no longer race with SIGKILL 2015-04-17 09:04:06 -04:00
range.c kernel: avoid overflow in cmp_range 2015-01-17 10:02:23 +13:00
reboot.c kernel/reboot.c: add orderly_reboot for graceful reboot 2015-04-15 16:35:23 -07:00
relay.c kernel/relay.c: use kvfree() in relay_free_page_array() 2015-06-30 19:44:59 -07:00
resource.c kernel/resource.c: remove deprecated __check_region() and friends 2015-04-15 16:35:22 -07:00
seccomp.c seccomp, filter: add and use bpf_prog_create_from_user from seccomp 2015-05-09 17:35:05 -04:00
signal.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2015-06-27 13:26:03 -07:00
smp.c smp: Fix error case handling in smp_call_function_*() 2015-04-19 13:19:23 -07:00
smpboot.c watchdog: add watchdog_cpumask sysctl to assist nohz 2015-06-24 17:49:40 -07:00
smpboot.h
softirq.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-02-09 15:24:03 -08:00
stacktrace.c stacktrace: introduce snprint_stack_trace for buffer output 2014-12-13 12:42:48 -08:00
stop_machine.c sched/stop_machine: Fix deadlock between multiple stop_two_cpus() 2015-06-19 10:03:12 +02:00
sys.c prctl: more prctl(PR_SET_MM_*) checks 2015-06-25 17:00:37 -07:00
sys_ni.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
sysctl.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2015-07-03 15:20:57 -07:00
sysctl_binary.c kernel: add panic_on_warn 2014-12-10 17:41:10 -08:00
system_certificates.S
system_keyring.c
task_work.c
taskstats.c netlink: make nlmsg_end() and genlmsg_end() void 2015-01-18 01:03:45 -05:00
test_kprobes.c
torture.c rcu: Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() 2015-05-27 12:56:15 -07:00
tracepoint.c
tsacct.c
uid16.c groups: Consolidate the setgroups permission checks 2014-12-05 17:19:27 -06:00
up.c
user-return-notifier.c
user.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2014-12-17 12:31:40 -08:00
user_namespace.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2014-12-17 12:31:40 -08:00
utsname.c copy address of proc_ns_ops into ns_common 2014-12-04 14:34:47 -05:00
utsname_sysctl.c
watchdog.c watchdog: add watchdog_cpumask sysctl to assist nohz 2015-06-24 17:49:40 -07:00
workqueue.c Minor merge needed, due to function move. 2015-07-01 10:49:25 -07:00
workqueue_internal.h