Anton Vorontsov
cb79295e20
cpu: introduce clear_tasks_mm_cpumask() helper ...
Many architectures clear tasks' mm_cpumask like this:
read_lock(&tasklist_lock);
for_each_process(p) {
if (p->mm)
cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
}
read_unlock(&tasklist_lock);
Depending on the context, the code above may have several problems,
such as:
1. Working with task->mm w/o getting mm or grabing the task lock is
dangerous as ->mm might disappear (exit_mm() assigns NULL under
task_lock(), so tasklist lock is not enough).
2. Checking for process->mm is not enough because process' main
thread may exit or detach its mm via use_mm(), but other threads
may still have a valid mm.
This patch implements a small helper function that does things
correctly, i.e.:
1. We take the task's lock while whe handle its mm (we can't use
get_task_mm()/mmput() pair as mmput() might sleep);
2. To catch exited main thread case, we use find_lock_task_mm(),
which walks up all threads and returns an appropriate task
(with task lock held).
Also, Per Peter Zijlstra's idea, now we don't grab tasklist_lock in
the new helper, instead we take the rcu read lock. We can do this
because the function is called after the cpu is taken down and marked
offline, so no new tasks will get this cpu set in their mm mask.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-31 17:49:29 -07:00
KGDB/KDB regression fixes
2012-04-04 17:26:08 -07:00
Merge branch 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-05-24 11:39:34 -07:00
kernel/irq/manage.c: use the pr_foo() infrastructure to prefix printks
2012-05-31 17:49:26 -07:00
PM / Hibernate: Use get_gendisk to verify partition if resume_file is integer format
2012-05-18 20:44:59 +02:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2012-05-23 17:42:39 -07:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-05-24 13:29:46 -07:00
Merge branch 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-05-24 11:39:34 -07:00
Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2012-01-08 12:19:57 -08:00
kernel/async: remove redundant declaration.
2012-01-13 09:32:18 +10:30
constify path argument of audit_log_d_path()
2012-03-20 21:29:40 -04:00
audit: remove AUDIT_SETUP_CONTEXT as it isn't used
2012-01-17 16:16:57 -05:00
audit: allow interfield comparison in audit rules
2012-01-17 16:17:01 -05:00
seccomp: remove duplicated failure logging
2012-04-14 11:13:20 +10:00
userns: Teach inode_capable to understand inodes whose uids map to other namespaces.
2012-05-15 14:59:24 -07:00
kernel: cgroup: push rcu read locking from css_is_ancestor() to callsite
2012-05-29 16:22:20 -07:00
cgroup: convert all non-memcg controllers to the new cftype interface
2012-04-01 12:09:55 -07:00
new helper: sigsuspend()
2012-05-21 23:52:30 -04:00
cpu: introduce clear_tasks_mm_cpumask() helper
2012-05-31 17:49:29 -07:00
kernel/cpu_pm.c: fix various typos
2012-05-31 17:49:27 -07:00
Merge branch 'for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2012-05-22 17:40:19 -07:00
Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
2011-11-06 19:44:47 -08:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2012-05-23 17:42:39 -07:00
Remove all #inclusions of asm/system.h
2012-03-28 18:30:03 +01:00
stack usage: add pid to warning printk in check_stack_usage
2012-05-31 17:49:28 -07:00
extable: Skip sorting if sorted at build time.
2012-04-19 15:06:55 -07:00
fork: call complete_vfork_done() after clearing child_tid and flushing rss-counters
2012-05-31 17:49:29 -07:00
PM / Freezer: Remove references to TIF_FREEZE in comments
2012-03-04 23:08:54 +01:00
futex: Mark get_robust_list as deprecated
2012-03-29 11:37:17 +02:00
futex: Mark get_robust_list as deprecated
2012-03-29 11:37:17 +02:00
userns: Convert in_group_p and in_egroup_p to use kgid_t
2012-05-03 03:29:33 -07:00
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2011-11-28 08:43:52 -08:00
hung task debugging: Inject NMI when hung and going to panic
2012-04-25 12:39:25 +02:00
irq_work: fix compile failure on tile from missing include
2012-04-13 13:15:16 -04:00
itimer: Use printk_once instead of WARN_ONCE
2012-04-10 11:00:30 +02:00
static keys: Inline the static_key_enabled() function
2012-02-28 20:01:08 +01:00
vsprintf: fix %ps on non symbols when using kallsyms
2012-05-29 16:22:32 -07:00
locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage
2012-03-23 13:18:57 +01:00
locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage
2012-03-23 13:18:57 +01:00
Merge branch 'akpm' (Andrew's patch-bomb)
2012-03-28 17:19:28 -07:00
[media] kernel:kfifo: export __kfifo_max_r symbol
2012-04-11 18:24:37 -03:00
kmod.c: fix kernel-doc warning
2012-05-31 17:49:28 -07:00
kprobes: return proper error code from register_kprobe()
2012-03-05 15:49:42 -08:00
kernel: ksysfs.c is implicitly using stat.h
2011-10-31 09:20:13 -04:00
freezer: kill unused set_freezable_with_signal()
2011-11-23 09:28:17 -08:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
lockdep: Add CPU-idle/offline warning to lockdep-RCU splat
2012-02-21 09:06:06 -08:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
smp: Add generic smpboot facility
2012-04-26 12:06:09 +02:00
Guard check in module loader against integer overflow
2012-05-23 22:28:53 +09:30
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
sched/rt: Use schedule_preempt_disabled()
2012-03-01 10:28:03 +01:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
padata: Fix cpu hotplug
2012-03-29 19:52:46 +08:00
panic: fix stack dump print on direct call to panic()
2012-04-12 13:12:12 -07:00
params: replace printk(KERN_<LVL>...) with pr_<lvl>(...)
2012-05-04 17:28:18 -07:00
mm: add a low limit to alloc_large_system_hash
2012-05-24 00:28:21 -04:00
pidns: add reboot_pid_ns() to handle the reboot syscall
2012-03-28 17:14:36 -07:00
[S390] cputime: add sparse checking and cleanup
2011-12-15 14:56:19 +01:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
printk() - isolate KERN_CONT users from ordinary complete lines
2012-05-14 12:36:45 -07:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
userns: Convert ptrace, kill, set_priority permission checks to work with kuids and kgids
2012-05-03 03:28:51 -07:00
range: fix bogus misuse of module.h to get printk()
2011-10-31 09:20:11 -04:00
rcu: Allow nesting of rcu_idle_enter() and rcu_idle_exit()
2012-02-21 09:06:12 -08:00
rcu: Make exit_rcu() more precise and consolidate
2012-05-02 14:48:27 -07:00
rcu: Add RCU_NONIDLE() for idle-loop RCU read-side critical sections
2012-02-21 09:06:13 -08:00
rcu: Make exit_rcu() more precise and consolidate
2012-05-02 14:48:27 -07:00
rcu: Add rcutorture test for call_srcu()
2012-04-30 10:48:26 -07:00
Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
2012-05-14 08:41:46 +02:00
Merge branches 'barrier.2012.05.09a', 'fixes.2012.04.26a', 'inline.2012.05.02b' and 'srcu.2012.05.07b' into HEAD
2012-05-11 10:14:21 -07:00
Merge branches 'barrier.2012.05.09a', 'fixes.2012.04.26a', 'inline.2012.05.02b' and 'srcu.2012.05.07b' into HEAD
2012-05-11 10:14:21 -07:00
rcu: Make rcu_barrier() less disruptive
2012-05-09 14:27:54 -07:00
relay: prevent integer overflow in relay_open()
2012-02-10 09:04:49 +01:00
rescounters: add res_counter_uncharge_until()
2012-05-29 16:22:27 -07:00
kernel/resource.c: correct the comment of allocate_resource()
2012-05-31 17:49:26 -07:00
lockdep, rtmutex, bug: Show taint flags on error
2011-12-06 08:16:49 +01:00
rtmutex-tester: convert sysdev_class to a regular subsystem
2011-12-14 14:54:22 -08:00
Revert "rcu: Permit rt_mutex_unlock() with irqs disabled"
2011-12-11 10:33:18 -08:00
Remove all #inclusions of asm/system.h
2012-03-28 18:30:03 +01:00
seccomp: fix build warnings when there is no CONFIG_SECCOMP_FILTER
2012-04-18 12:24:52 +10:00
semaphore: fix improper comment reference to mutex
2012-04-05 17:15:55 -07:00
Merge branch 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-05-24 11:39:34 -07:00
smp: Implement kick_all_cpus_sync()
2012-05-08 12:35:06 +02:00
smp, idle: Allocate idle thread for each possible cpu during boot
2012-05-03 19:32:34 +02:00
smp: Fix idle_thread_init() inline stub
2012-05-04 12:52:25 +02:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-03-20 10:32:09 -07:00
locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage
2012-03-23 13:18:57 +01:00
rcu: Implement per-domain single-threaded call_srcu() state machine
2012-04-30 10:48:25 -07:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
2011-11-06 19:44:47 -08:00
kmod: convert two call sites to call_usermodehelper_fns()
2012-05-31 17:49:28 -07:00
Cross Memory Attach
2011-10-31 17:30:44 -07:00
sysctl: fix write access to dmesg_restrict/kptr_restrict
2012-04-05 14:51:43 +10:00
binary_sysctl(): fix memory leak
2011-12-20 10:25:04 -08:00
Make TASKSTATS require root access
2011-09-19 17:04:37 -07:00
time: Remove bogus comments
2012-03-15 18:17:55 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2012-05-23 17:42:39 -07:00
static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]()
2012-02-24 10:05:59 +01:00
[S390] cputime: add sparse checking and cleanup
2011-12-15 14:56:19 +01:00
userns: Convert setting and getting uid and gid system calls to use kuid and kgid
2012-05-03 03:28:41 -07:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
userns: Silence silly gcc warning.
2012-05-19 15:44:40 -06:00
userns: Store uid and gid values in struct cred with kuid_t and kgid_t types
2012-05-03 03:28:38 -07:00
userns: Use cred->user_ns instead of cred->user->user_ns
2012-04-07 16:55:51 -07:00
Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
2011-11-06 19:44:47 -08:00
lockdep/waitqueues: Add better annotation
2011-12-21 10:07:39 +01:00
watchdog: add check for suspended vm in softlockup detector
2012-04-08 12:49:03 +03:00
lockdep: fix oops in processing workqueue
2012-05-15 08:08:31 -07:00
cb79295e20