Peter Zijlstra 25834c73f9 sched: Fix a race between __kthread_bind() and sched_setaffinity() ...

Because sched_setscheduler() checks p->flags & PF_NO_SETAFFINITY
without locks, a caller might observe an old value and race with the
set_cpus_allowed_ptr() call from __kthread_bind() and effectively undo
it:

	__kthread_bind()
	  do_set_cpus_allowed()
						<SYSCALL>
						  sched_setaffinity()
						    if (p->flags & PF_NO_SETAFFINITIY)
						    set_cpus_allowed_ptr()
	  p->flags |= PF_NO_SETAFFINITY

Fix the bug by putting everything under the regular scheduler locks.

This also closes a hole in the serialization of task_struct::{nr_,}cpus_allowed.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dedekind1@gmail.com
Cc: juri.lelli@arm.com
Cc: mgorman@suse.de
Cc: riel@redhat.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20150515154833.545640346@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2015-08-12 12:06:09 +02:00

..

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

Merge tag 'pm+acpi-4.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

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

Merge tag 'trace-v4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2015-06-26 14:02:43 -07:00

sched

sched: Fix a race between __kthread_bind() and sched_setaffinity()

2015-08-12 12:06:09 +02:00

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

sched: Introduce the 'trace_sched_waking' tracepoint

2015-08-03 12:21:22 +02:00

.gitignore

…

acct.c

acct: check FMODE_CAN_WRITE

2015-04-11 22:27:55 -04:00

async.c

kernel/async.c: switch to pr_foo()

2014-10-09 22:26:04 -04:00

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

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

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

kernel/backtracetest.c: replace no level printk by pr_info()

2014-06-04 16:54:14 -07:00

bounds.c

page-cgroup: get rid of NR_PCG_FLAGS

2014-08-08 15:57:18 -07:00

capability.c

kernel: conditionally support non-root users, groups and capabilities

2015-04-15 16:35:22 -07:00

cgroup_freezer.c

cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes

2014-07-15 11:05:09 -04:00

cgroup.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

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_pm.c

…

cpu.c

stop_machine: Unexport __stop_machine()

2015-08-03 12:21:26 +02:00

cpuset.c

kernel, cpuset: remove exception for __GFP_THISNODE

2015-04-14 16:49:03 -07:00

crash_dump.c

crash_dump: Make is_kdump_kernel() accessible from modules

2014-08-25 15:42:19 -07:00

cred.c

kernel: conditionally support non-root users, groups and capabilities

2015-04-15 16:35:22 -07:00

delayacct.c

delayacct: Remove braindamaged type conversions

2014-07-23 10:18:06 -07:00

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

sched/cputime: Guarantee stime + utime == rtime

2015-08-03 12:21:21 +02:00

freezer.c

freezer: remove obsolete comments in __thaw_task()

2014-10-21 23:44:20 +02:00

futex_compat.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

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

percpu: Convert remaining __get_cpu_var uses in 3.18-rcX

2014-10-29 11:18:18 -04:00

jump_label.c

module, jump_label: Fix module locking

2015-05-27 11:09:50 +09:30

kallsyms.c

kernel/kallsyms.c: use __seq_open_private()

2014-10-14 02:18:16 +02:00

kcmp.c

kcmp: fix standard comparison bug

2014-09-10 15:42:12 -07:00

Kconfig.freezer

…

Kconfig.hz

…

Kconfig.locks

locking/qrwlock: Rename QUEUE_RWLOCK to QUEUED_RWLOCKS

2015-05-12 09:46:00 +02:00

Kconfig.preempt

…

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

kobject: Make support for uevent_helper optional.

2014-04-25 12:00:49 -07:00

kthread.c

sched: Fix a race between __kthread_bind() and sched_setaffinity()

2015-08-12 12:06:09 +02:00

latencytop.c

kernel/latencytop.c: convert seq_printf to seq_puts

2014-06-04 16:54:15 -07:00

Makefile

make certificate list change message more useful

2015-07-02 16:42:13 -07:00

module_signing.c

…

module-internal.h

…

module.c

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

2015-07-01 10:49:25 -07:00

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

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

2015-07-01 10:49:25 -07:00

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

pid.c

fork: report pid reservation failure properly

2015-04-17 09:04:06 -04:00

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

stop_machine: Remove cpu_stop_work's from list in cpu_stop_park()

2015-08-03 12:21:28 +02:00

sys_ni.c

kernel: conditionally support non-root users, groups and capabilities

2015-04-15 16:35:22 -07:00

sys.c

prctl: more prctl(PR_SET_MM_*) checks

2015-06-25 17:00:37 -07:00

sysctl_binary.c

kernel: add panic_on_warn

2014-12-10 17:41:10 -08:00

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

system_certificates.S

…

system_keyring.c

KEYS: validate certificate trust only with builtin keys

2014-07-17 09:35:17 -04:00

task_work.c

…

taskstats.c

netlink: make nlmsg_end() and genlmsg_end() void

2015-01-18 01:03:45 -05:00

test_kprobes.c

kernel/test_kprobes.c: use current logging functions

2014-08-08 15:57:18 -07:00

torture.c

rcu: Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE()

2015-05-27 12:56:15 -07:00

tracepoint.c

tracing: syscall_regfunc() should not skip kernel threads

2014-06-21 00:15:26 -04:00

tsacct.c

sched: Make task->start_time nanoseconds based

2014-07-23 10:18:05 -07:00

uid16.c

groups: Consolidate the setgroups permission checks

2014-12-05 17:19:27 -06:00

up.c

smp: Rename __smp_call_function_single() to smp_call_function_single_async()

2014-02-24 14:47:15 -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

user-return-notifier.c

scheduler: Replace __get_cpu_var with this_cpu_ptr

2014-08-26 13:45:45 -04:00

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

utsname_sysctl.c

sysctl: convert use of typedef ctl_table to struct ctl_table

2014-06-06 16:08:16 -07:00

utsname.c

copy address of proc_ns_ops into ns_common

2014-12-04 14:34:47 -05:00

watchdog.c

watchdog: add watchdog_cpumask sysctl to assist nohz

2015-06-24 17:49:40 -07:00

workqueue_internal.h

workqueue: rename manager_mutex to attach_mutex

2014-05-20 10:59:32 -04:00

workqueue.c

sched: Fix a race between __kthread_bind() and sched_setaffinity()

2015-08-12 12:06:09 +02:00