Different tree maintainers picked up independently generated
trivial compile fixes based on linux-next testing, resulting
in some cases where a file would have got more than one addition
of module.h once everything was all merged together.
Delete any duplicates so includecheck isn't complaining about
anything related to module.h/export.h changes.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
In the jump label enabled case, calling static_key_enabled()
results in a function call. The function returns the results of
a compare, so it really doesn't need the overhead of a full
function call. Let's make it 'static inline' for both the jump
label enabled and disabled cases.
Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: a.p.zijlstra@chello.nl
Cc: rostedt@goodmis.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/201202281849.q1SIn1p2023270@int-mx10.intmail.prod.int.phx2.redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The major features of this series are:
- making RCU more aggressive about entering dyntick-idle mode in order to
improve energy efficiency
- converting a few more call_rcu()s to kfree_rcu()s
- applying a number of rcutree fixes and cleanups to rcutiny
- removing CONFIG_SMP #ifdefs from treercu
- allowing RCU CPU stall times to be set via sysfs
- adding CPU-stall capability to rcutorture
- adding more RCU-abuse diagnostics
- updating documentation
- fixing yet more issues located by the still-ongoing top-to-bottom
inspection of RCU, this time with a special focus on the
CPU-hotplug code path.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If kzalloc() for TYPE_DATA failed on a given cpu, previous chunk
of TYPE_INST will be leaked. Fix it.
Thanks to Peter Zijlstra for suggesting this better solution. It
should work as long as the initial value of the region is all
0's and that's the case of static (per-cpu) memory allocation.
Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/1330391978-28070-1-git-send-email-namhyung.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Handle pending irqs in irq_startup()
genirq: Unmask oneshot irqs when thread was not woken
Currently, during CPU hotplug, the cpuset callbacks modify the cpusets
to reflect the state of the system, and this handling is asymmetric.
That is, upon CPU offline, that CPU is removed from all cpusets. However
when it comes back online, it is put back only to the root cpuset.
This gives rise to a significant problem during suspend/resume. During
suspend, we offline all non-boot cpus and during resume we online them back.
Which means, after a resume, all cpusets (except the root cpuset) will be
restricted to just one single CPU (the boot cpu). But the whole point of
suspend/resume is to restore the system to a state which is as close as
possible to how it was before suspend.
So to fix this, don't touch cpusets during suspend/resume. That is, modify
the cpuset-related CPU hotplug callback to just ignore CPU hotplug when it
is initiated as part of the suspend/resume sequence.
Reported-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/4F460D7B.1020703@linux.vnet.ibm.com
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch is intentionally incomplete to simplify the review.
It ignores ep_unregister_pollwait() which plays with the same wqh.
See the next change.
epoll assumes that the EPOLL_CTL_ADD'ed file controls everything
f_op->poll() needs. In particular it assumes that the wait queue
can't go away until eventpoll_release(). This is not true in case
of signalfd, the task which does EPOLL_CTL_ADD uses its ->sighand
which is not connected to the file.
This patch adds the special event, POLLFREE, currently only for
epoll. It expects that init_poll_funcptr()'ed hook should do the
necessary cleanup. Perhaps it should be defined as EPOLLFREE in
eventpoll.
__cleanup_sighand() is changed to do wake_up_poll(POLLFREE) if
->signalfd_wqh is not empty, we add the new signalfd_cleanup()
helper.
ep_poll_callback(POLLFREE) simply does list_del_init(task_list).
This make this poll entry inconsistent, but we don't care. If you
share epoll fd which contains our sigfd with another process you
should blame yourself. signalfd is "really special". I simply do
not know how we can define the "right" semantics if it used with
epoll.
The main problem is, epoll calls signalfd_poll() once to establish
the connection with the wait queue, after that signalfd_poll(NULL)
returns the different/inconsistent results depending on who does
EPOLL_CTL_MOD/signalfd_read/etc. IOW: apart from sigmask, signalfd
has nothing to do with the file, it works with the current thread.
In short: this patch is the hack which tries to fix the symptoms.
It also assumes that nobody can take tasklist_lock under epoll
locks, this seems to be true.
Note:
- we do not have wake_up_all_poll() but wake_up_poll()
is fine, poll/epoll doesn't use WQ_FLAG_EXCLUSIVE.
- signalfd_cleanup() uses POLLHUP along with POLLFREE,
we need a couple of simple changes in eventpoll.c to
make sure it can't be "lost".
Reported-by: Maxime Bizon <mbizon@freebox.fr>
Cc: <stable@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes IRQ_DOMAIN usable on MIPS. It uses an ugly workaround
to preserve current behaviour so that MIPS has time to add irq_domain
registration to the irq controller drivers. The workaround will be
removed in Linux v3.6
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
So here's a boot tested patch on top of Jason's series that does
all the cleanups I talked about and turns jump labels into a
more intuitive to use facility. It should also address the
various misconceptions and confusions that surround jump labels.
Typical usage scenarios:
#include <linux/static_key.h>
struct static_key key = STATIC_KEY_INIT_TRUE;
if (static_key_false(&key))
do unlikely code
else
do likely code
Or:
if (static_key_true(&key))
do likely code
else
do unlikely code
The static key is modified via:
static_key_slow_inc(&key);
...
static_key_slow_dec(&key);
The 'slow' prefix makes it abundantly clear that this is an
expensive operation.
I've updated all in-kernel code to use this everywhere. Note
that I (intentionally) have not pushed through the rename
blindly through to the lowest levels: the actual jump-label
patching arch facility should be named like that, so we want to
decouple jump labels from the static-key facility a bit.
On non-jump-label enabled architectures static keys default to
likely()/unlikely() branches.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jason Baron <jbaron@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: a.p.zijlstra@chello.nl
Cc: mathieu.desnoyers@efficios.com
Cc: davem@davemloft.net
Cc: ddaney.cavm@gmail.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20120222085809.GA26397@elte.hu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Current the initial SCHED_RR timeslice of init_task is HZ, which means
1s, and is not same as the default SCHED_RR timeslice DEF_TIMESLICE.
Change that initial timeslice to the DEF_TIMESLICE.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
[ s/DEF_TIMESLICE/RR_TIMESLICE/g ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4F3C9995.3010800@ct.jp.nec.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
select_idle_sibling() is called from select_task_rq_fair(), which
already has the RCU read lock held.
Signed-off-by: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120217030409.11748.12491.stgit@abhimanyu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit 1ac9bc69 ("sched/tracing: Add a new tracepoint for sleeptime")
added a new sched:sched_stat_sleeptime tracepoint.
It's broken: the first sample we get on a task might be bad because
of a stale sleep_start value that wasn't reset at the last task switch
because the tracepoint was not active.
It also breaks the existing schedstat samples due to the side
effects of:
- se->statistics.sleep_start = 0;
...
- se->statistics.block_start = 0;
Nor do I see means to fix it without adding overhead to the scheduler
fast path, which I'm not willing to for the sake of redundant
instrumentation.
Most importantly, sleep time information can already be constructed
by tracing context switches and wakeups, and taking the timestamp
difference between the schedule-out, the wakeup and the schedule-in.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/n/tip-pc4c9qhl8q6vg3bs4j6k0rbd@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
synchronize_sched_expedited() is spamming CONFIG_DEBUG_PREEMPT=y
users with an unintended warning from the cpu_is_offline() check: use
raw_smp_processor_id() instead of smp_processor_id() there.
Because the warning is under a get_online_cpus(), it is not possible
for any CPUs to go offline, though it is quite possible that the
task might migrate between the raw_smp_processor_id() and the check
of cpu_is_offline(). This is not a problem because the task cannot
migrate from an offline CPU to an online one or vice versa. The point
of the check is to verify that synchronize_sched_expedited() is not
called from an offline CPU, for example, from a CPU_DYING notifier, or,
more important, from an outgoing CPU making its way from its CPU_DYING
notifiers to the idle loop.
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Walking through the tasklist in cgroup_enable_task_cg_list() inside
an RCU read side critical section is not enough because:
- RCU is not (yet) safe against while_each_thread()
- If we use only RCU, a forking task that has passed cgroup_post_fork()
without seeing use_task_css_set_links == 1 is not guaranteed to have
its child immediately visible in the tasklist if we walk through it
remotely with RCU. In this case it will be missing in its css_set's
task list.
Thus we need to traverse the list (unfortunately) under the
tasklist_lock. It makes us safe against while_each_thread() and also
make sure we see all forked task that have been added to the tasklist.
As a secondary effect, reading and writing use_task_css_set_links are
now well ordered against tasklist traversing and modification. The new
layout is:
CPU 0 CPU 1
use_task_css_set_links = 1 write_lock(tasklist_lock)
read_lock(tasklist_lock) add task to tasklist
do_each_thread() { write_unlock(tasklist_lock)
add thread to css set links if (use_task_css_set_links)
} while_each_thread() add thread to css set links
read_unlock(tasklist_lock)
If CPU 0 traverse the list after the task has been added to the tasklist
then it is correctly added to the css set links. OTOH if CPU 0 traverse
the tasklist before the new task had the opportunity to be added to the
tasklist because it was too early in the fork process, then CPU 1
catches up and add the task to the css set links after it added the task
to the tasklist. The right value of use_task_css_set_links is guaranteed
to be visible from CPU 1 due to the LOCK/UNLOCK implicit barrier properties:
the read_unlock on CPU 0 makes the write on use_task_css_set_links happening
and the write_lock on CPU 1 make the read of use_task_css_set_links that comes
afterward to return the correct value.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Remove the stale comment about RCU protection. Many callers
(all of them?) of cgroup_enable_task_cg_list() don't seem
to be in an RCU read side critical section. Besides, RCU is
not helpful to protect against while_each_thread().
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit handles workloads that transition quickly between idle and
non-idle, and where the CPU's callbacks cannot be invoked, but where
RCU does not have anything immediate for the CPU to do. Without this
patch, the RCU_FAST_NO_HZ code can be invoked repeatedly on each entry
to idle. The commit sets the per-CPU rcu_dyntick_holdoff variable to
hold off further attempts for a tick.
Reported-by: "Abou Gazala, Neven M" <neven.m.abou.gazala@intel.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
If a softirq is pending, the current CPU has RCU callbacks pending,
and RCU does not immediately need anything from this CPU, then the
current code resets the RCU_FAST_NO_HZ state machine. This means that
upon exit from the subsequent softirq handler, RCU_FAST_NO_HZ will
try really hard to force RCU into dyntick-idle mode. And if the same
conditions hold after a few tries (determined by RCU_IDLE_OPT_FLUSHES),
the same situation can repeat, possibly endlessly. This scenario is
not particularly good for battery lifetime.
This commit therefore suppresses the early exit from the RCU_FAST_NO_HZ
state machine in the case where there is a softirq pending. This change
forces the state machine to retain its memory, and to enter holdoff if
this condition persists.
Reported-by: "Abou Gazala, Neven M" <neven.m.abou.gazala@intel.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
RCU, RCU-bh, and RCU-sched read-side critical sections are forbidden
in the inner idle loop, that is, between the rcu_idle_enter() and the
rcu_idle_exit() -- RCU will happily ignore any such read-side critical
sections. However, things like powertop need tracepoints in the inner
idle loop.
This commit therefore provides an RCU_NONIDLE() macro that can be used to
wrap code in the idle loop that requires RCU read-side critical sections.
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Use of RCU in the idle loop is incorrect, quite a few instances of
just that have made their way into mainline, primarily event tracing.
The problem with RCU read-side critical sections on CPUs that RCU believes
to be idle is that RCU is completely ignoring the CPU, along with any
attempts and RCU read-side critical sections.
The approaches of eliminating the offending uses and of pushing the
definition of idle down beyond the offending uses have both proved
impractical. The new approach is to encapsulate offending uses of RCU
with rcu_idle_exit() and rcu_idle_enter(), but this requires nesting
for code that is invoked both during idle and and during normal execution.
Therefore, this commit modifies rcu_idle_enter() and rcu_idle_exit() to
permit nesting.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
There is now an unconditional check for rcu_head misalignment in
__call_rcu(), so remove the old conditional one in debug_rcu_head_queue().
Reported-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression e,e1;
constant c;
@@
*e = c
... when != e = e1
when != &e
when != true IS_ERR(e)
*PTR_ERR(e)
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reported-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Fix a bonehead error introduced when adding event tracing to rcutorture.
Move the traces to follow the NULL-pointer checks.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The expedited RCU primitives can be quite useful, but they have some
high costs as well. This commit updates and creates docbook comments
calling out the costs, and updates the RCU documentation as well.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Because newly offlined CPUs continue executing after completing the
CPU_DYING notifiers, they legitimately enter the scheduler and use
RCU while appearing to be offline. This calls for a more sophisticated
approach as follows:
1. RCU marks the CPU online during the CPU_UP_PREPARE phase.
2. RCU marks the CPU offline during the CPU_DEAD phase.
3. Diagnostics regarding use of read-side RCU by offline CPUs use
RCU's accounting rather than the cpu_online_map. (Note that
__call_rcu() still uses cpu_online_map to detect illegal
invocations within CPU_DYING notifiers.)
4. Offline CPUs are prevented from hanging the system by
force_quiescent_state(), which pays attention to cpu_online_map.
Some additional work (in a later commit) will be needed to
guarantee that force_quiescent_state() waits a full jiffy before
assuming that a CPU is offline, for example, when called from
idle entry. (This commit also makes the one-jiffy wait
explicit, since the old-style implicit wait can now be defeated
by RCU_FAST_NO_HZ and by rcutorture.)
This approach avoids the false positives encountered when attempting to
use more exact classification of CPU online/offline state.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
It is illegal to use RCU from a CPU that has reported idleness or
offlinedness to RCU. However, it can be quite difficult to determine
from a stack trace whether or not a given CPU is idle or offline.
Therefore, this commit adds idle/offline diagnostics to the lockdep-RCU
error message.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The rcu_prepare_for_idle() function is always called with interrupts
disabled, so there is no reason to disable interrupts again within
rcu_prepare_for_idle(). Therefore, this commit removes all of the
interrupt disabling, also removing a latent disabling-unbalance bug.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Now that TREE_RCU and TREE_PREEMPT_RCU no longer do anything different
for the single-CPU case, there is no need for multiple definitions of
synchronize_sched_expedited(). It is no longer in any sense a plug-in,
so move it from kernel/rcutree_plugin.h to kernel/rcutree.c.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Although it is legal to use RCU during early boot, it is anything
but legal to use RCU at runtime from an offlined CPU. After all, RCU
explicitly ignores offlined CPUs. This commit therefore adds checks
for runtime use of RCU from offlined CPUs.
These checks are not perfect, in particular, they can be subverted
through use of things like rcu_dereference_raw(). Note that it is not
possible to put checks in rcu_read_lock() and friends due to the fact
that these primitives are used in code that might be used under either
RCU or lock-based protection, which means that checking rcu_read_lock()
gets you fat piles of false positives.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Add module parameters to rcutorture that induce a CPU stall.
The stall_cpu parameter specifies how long to stall in seconds,
defaulting to zero, which indicates no stalling is to be undertaken.
The stall_cpu_holdoff parameter specifies how many seconds after
insmod (or boot, if rcutorture is built into the kernel) that this
stall is to start. The default value for stall_cpu_holdoff is ten
seconds.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
When rcutorture is started automatically at boot time, it might well
also start CPU-hotplug operations at that time, which might not be
desirable. This commit therefore adds an rcutorture parameter that
allows CPU-hotplug operations to be held off for the specified number
of seconds after the start of boot.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
There have been situations where RCU CPU stall warnings were caused by
issues in scheduling-clock timer initialization. To make it easier to
track these down, this commit causes the RCU CPU stall-warning messages
to print out the number of scheduling-clock interrupts taken in the
current grace period for each stalled CPU.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The default CONFIG_RCU_CPU_STALL_TIMEOUT value of 60 seconds has served
Linux users well for production use for quite some time. However, for
debugging, there will be more than three minutes between subsequent
stall-warning messages. This can be an annoyingly long wait if you
are trying to work out where the offending infinite loop is hiding.
Therefore, this commit provides a rcu_cpu_stall_timeout sysfs
parameter that may be adjusted at boot time and at runtime to speed
up debugging.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Now that both TINY_RCU and TINY_PREEMPT_RCU have been in place for awhile,
it is time to remove UP support from TREE_RCU, which is what this commit
does.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The inner idle loop is an extended quiescent state for all flavors
of RCU, but there have been recent bug involving use of RCU read-side
primitives from within the idle loop. Therefore, this commit enlists
lockdep-RCU to detect attempts to enter the inner idle loop while in
an RCU read-side critical section, emitting a lockdep-RCU splat if so.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The recent updates to RCU_CPU_FAST_NO_HZ have an rcu_needs_cpu() that
does more than just check for callbacks, so get the name for
rcu_preempt_needs_cpu() consistent with that change, now calling it
rcu_preempt_cpu_has_callbacks().
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This is a port of commit #82e78d80 from TREE_PREEMPT_RCU to
TINY_PREEMPT_RCU.
This commit uses the fact that current->rcu_boost_mutex is set
any time that the RCU_READ_UNLOCK_BOOSTED flag is set in the
current->rcu_read_unlock_special bitmask. This allows tests of
the bit to be changed to tests of the pointer, which in turn allows
the RCU_READ_UNLOCK_BOOSTED flag to be eliminated.
Please note that the check of current->rcu_read_unlock_special need not
change because any time that RCU_READ_UNLOCK_BOOSTED was set, so was
RCU_READ_UNLOCK_BLOCKED. Therefore, __rcu_read_unlock() can continue
testing current->rcu_read_unlock_special for non-zero, as before.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This is a port to TINY_RCU of Peter Zijlstra's commit #ec433f0c5
The rcu_read_unlock_special() function relies on in_irq() to exclude
scheduler activity from interrupt level. This fails because exit_irq()
can invoke the scheduler after clearing the preempt_count() bits that
in_irq() uses to determine that it is at interrupt level. This situation
can result in failures as follows:
$task IRQ SoftIRQ
rcu_read_lock()
/* do stuff */
<preempt> |= UNLOCK_BLOCKED
rcu_read_unlock()
--t->rcu_read_lock_nesting
irq_enter();
/* do stuff, don't use RCU */
irq_exit();
sub_preempt_count(IRQ_EXIT_OFFSET);
invoke_softirq()
ttwu();
spin_lock_irq(&pi->lock)
rcu_read_lock();
/* do stuff */
rcu_read_unlock();
rcu_read_unlock_special()
rcu_report_exp_rnp()
ttwu()
spin_lock_irq(&pi->lock) /* deadlock */
rcu_read_unlock_special(t);
This can be triggered 'easily' because invoke_softirq() immediately does
a ttwu() of ksoftirqd/# instead of doing the in-place softirq stuff first,
but even without that the above happens.
Cure this by also excluding softirqs from the rcu_read_unlock_special()
handler and ensuring the force_irqthreads ksoftirqd/# wakeup is done
from full softirq context.
It is also necessary to delay the ->rcu_read_lock_nesting decrement until
after rcu_read_unlock_special(). This delay is handled by the commit
"Protect __rcu_read_unlock() against scheduler-using irq handlers".
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This is a port of commit #b0d3041 from TREE_RCU to TREE_PREEMPT_RCU.
Under some rare but real combinations of configuration parameters, RCU
callbacks are posted during early boot that use kernel facilities that are
not yet initialized. Therefore, when these callbacks are invoked, hard
hangs and crashes ensue. This commit therefore prevents RCU callbacks
from being invoked until after the scheduler is fully up and running,
as in after multiple tasks have been spawned.
It might well turn out that a better approach is to identify the specific
RCU callbacks that are causing this problem, but that discussion will
wait until such time as someone really needs an RCU callback to be invoked
(as opposed to merely registered) during early boot.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This is a port of commit #be0e1e21 to TINY_PREEMPT_RCU. This uses
noinline to prevent rcu_read_unlock_special() from being inlined into
__rcu_read_unlock().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit ports commit #10f39bb1b2 (rcu: protect __rcu_read_unlock()
against scheduler-using irq handlers) from TREE_PREEMPT_RCU to
TINY_PREEMPT_RCU. The following is a corresponding port of that
commit message.
The addition of RCU read-side critical sections within runqueue and
priority-inheritance critical sections introduced some deadlocks,
for example, involving interrupts from __rcu_read_unlock() where the
interrupt handlers call wake_up(). This situation can cause the
instance of __rcu_read_unlock() invoked from interrupt to do some
of the processing that would otherwise have been carried out by the
task-level instance of __rcu_read_unlock(). When the interrupt-level
instance of __rcu_read_unlock() is called with a scheduler lock held from
interrupt-entry/exit situations where in_irq() returns false, deadlock can
result. Of course, in a UP kernel, there are not really any deadlocks,
but the upper-level critical section can still be be fatally confused
by the lower-level critical section changing things out from under it.
This commit resolves these deadlocks by using negative values of the
per-task ->rcu_read_lock_nesting counter to indicate that an instance of
__rcu_read_unlock() is in flight, which in turn prevents instances from
interrupt handlers from doing any special processing. Note that nested
rcu_read_lock()/rcu_read_unlock() pairs are still permitted, but they will
never see ->rcu_read_lock_nesting go to zero, and will therefore never
invoke rcu_read_unlock_special(), thus preventing them from seeing the
RCU_READ_UNLOCK_BLOCKED bit should it be set in ->rcu_read_unlock_special.
This patch also adds a check for ->rcu_read_unlock_special being negative
in rcu_check_callbacks(), thus preventing the RCU_READ_UNLOCK_NEED_QS
bit from being set should a scheduling-clock interrupt occur while
__rcu_read_unlock() is exiting from an outermost RCU read-side critical
section.
Of course, __rcu_read_unlock() can be preempted during the time that
->rcu_read_lock_nesting is negative. This could result in the setting
of the RCU_READ_UNLOCK_BLOCKED bit after __rcu_read_unlock() checks it,
and would also result it this task being queued on the corresponding
rcu_node structure's blkd_tasks list. Therefore, some later RCU read-side
critical section would enter rcu_read_unlock_special() to clean up --
which could result in deadlock (OK, OK, fatal confusion) if that RCU
read-side critical section happened to be in the scheduler where the
runqueue or priority-inheritance locks were held.
To prevent the possibility of fatal confusion that might result from
preemption during the time that ->rcu_read_lock_nesting is negative,
this commit also makes rcu_preempt_note_context_switch() check for
negative ->rcu_read_lock_nesting, thus refraining from queuing the task
(and from setting RCU_READ_UNLOCK_BLOCKED) if we are already exiting
from the outermost RCU read-side critical section (in other words,
we really are no longer actually in that RCU read-side critical
section). In addition, rcu_preempt_note_context_switch() invokes
rcu_read_unlock_special() to carry out the cleanup in this case, which
clears out the ->rcu_read_unlock_special bits and dequeues the task
(if necessary), in turn avoiding needless delay of the current RCU grace
period and needless RCU priority boosting.
It is still illegal to call rcu_read_unlock() while holding a scheduler
lock if the prior RCU read-side critical section has ever had both
preemption and irqs enabled. However, the common use case is legal,
namely where then entire RCU read-side critical section executes with
irqs disabled, for example, when the scheduler lock is held across the
entire lifetime of the RCU read-side critical section.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The grace-period initialization sequence in rcu_start_gp() has a special
case for systems where the rcu_node tree is a single rcu_node structure.
This made sense some years ago when systems were smaller and up to 64
CPUs could share a single rcu_node structure, but now that large systems
are common and a given leaf rcu_node structure can support only 16 CPUs
(due to lock contention on the rcu_node's ->lock field), this optimization
is almost never taken. And even the small mobile platforms that might
make use of it might rather have the kernel text reduction.
Therefore, this commit removes the check for single-rcu_node trees.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
RCU's current CPU-offline code path dumps all of the outgoing CPU's
callbacks onto the RCU_NEXT_TAIL portion of the surviving CPU's
callback list. This means that all the ready-to-invoke callbacks from
the outgoing CPU must wait for another full RCU grace period. This was
just fine when CPU-hotplug events were rare, but there is increasing
evidence that users are planning to make increasing use of CPU hotplug.
Therefore, this commit changes the callback-dumping procedure so that
callbacks that are ready to invoke are moved to the RCU_DONE_TAIL
portion of the surviving CPU's callback list. This avoids running
these callbacks through a second unnecessary grace period.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Because quiescent states are now reported from offline CPUs in
CPU_DYING state, there is some possibility that such a CPU might
note the end of a grace period and attempt to start invoking
callbacks. This would be a very bad thing, and is supposed to
be prevented by the fact that the CPU_DYING CPU gets rid of all
its callbacks before reporting the quiescent state. However,
there is other CPU-offline code in the kernel, and it is quite
possible that someone will invoke RCU core processing from that
code. Therefore, this commit adds a warning for this case.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Currently, a given CPU is permitted to remain in dyntick-idle mode
indefinitely if it has only lazy RCU callbacks queued. This is vulnerable
to corner cases in NUMA systems, so limit the time to six seconds by
default. (Currently controlled by a cpp macro.)
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Make rcutorture check for CPU-hotplug failures and complain if there
were any.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Move ->qsmaskinit and blkd_tasks[] manipulation to the CPU_DYING
notifier. This simplifies the code by eliminating a potential
deadlock and by reducing the responsibilities of force_quiescent_state().
Also rename functions to make their connection to the CPU-hotplug
stages explicit.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
When CONFIG_RCU_FAST_NO_HZ is enabled, RCU will allow a given CPU to
enter dyntick-idle mode even if it still has RCU callbacks queued.
RCU avoids system hangs in this case by scheduling a timer for several
jiffies in the future. However, if all of the callbacks on that CPU
are from kfree_rcu(), there is no reason to wake the CPU up, as it is
not a problem to defer freeing of memory.
This commit therefore tracks the number of callbacks on a given CPU
that are from kfree_rcu(), and avoids scheduling the timer if all of
a given CPU's callbacks are from kfree_rcu().
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The push for energy efficiency will require that RCU tag rcu_head
structures to indicate whether or not their invocation is time critical.
This tagging is best carried out in the bottom bits of the ->next
pointers in the rcu_head structures. This tagging requires that the
rcu_head structures be properly aligned, so this commit adds the required
diagnostics.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
It is illegal to have a grace period within a same-flavor RCU read-side
critical section, so this commit adds lockdep-RCU checks to splat when
such abuse is encountered. This commit does not detect more elaborate
RCU deadlock situations. These situations might be a job for lockdep
enhancements.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Adding support to filter function trace event via perf
interface. It is now possible to use filter interface
in the perf tool like:
perf record -e ftrace:function --filter="(ip == mm_*)" ls
The filter syntax is restricted to the the 'ip' field only,
and following operators are accepted '==' '!=' '||', ending
up with the filter strings like:
ip == f1[, ]f2 ... || ip != f3[, ]f4 ...
with comma ',' or space ' ' as a function separator. If the
space ' ' is used as a separator, the right side of the
assignment needs to be enclosed in double quotes '"', e.g.:
perf record -e ftrace:function --filter '(ip == do_execve,sys_*,ext*)' ls
perf record -e ftrace:function --filter '(ip == "do_execve,sys_*,ext*")' ls
perf record -e ftrace:function --filter '(ip == "do_execve sys_* ext*")' ls
The '==' operator adds trace filter with same effect as would
be added via set_ftrace_filter file.
The '!=' operator adds trace filter with same effect as would
be added via set_ftrace_notrace file.
The right side of the '!=', '==' operators is list of functions
or regexp. to be added to filter separated by space.
The '||' operator is used for connecting multiple filter definitions
together. It is possible to have more than one '==' and '!='
operators within one filter string.
Link: http://lkml.kernel.org/r/1329317514-8131-8-git-send-email-jolsa@redhat.com
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Adding FILTER_TRACE_FN event field type for function tracepoint
event, so it can be properly recognized within filtering code.
Currently all fields of ftrace subsystem events share the common
field type FILTER_OTHER. Since the function trace fields need
special care within the filtering code we need to recognize it
properly, hence adding the FILTER_TRACE_FN event type.
Adding filter parameter to the FTRACE_ENTRY macro, to specify the
filter field type for the event.
Link: http://lkml.kernel.org/r/1329317514-8131-7-git-send-email-jolsa@redhat.com
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Adding perf registration support for the ftrace function event,
so it is now possible to register it via perf interface.
The perf_event struct statically contains ftrace_ops as a handle
for function tracer. The function tracer is registered/unregistered
in open/close actions.
To be efficient, we enable/disable ftrace_ops each time the traced
process is scheduled in/out (via TRACE_REG_PERF_(ADD|DELL) handlers).
This way tracing is enabled only when the process is running.
Intentionally using this way instead of the event's hw state
PERF_HES_STOPPED, which would not disable the ftrace_ops.
It is now possible to use function trace within perf commands
like:
perf record -e ftrace:function ls
perf stat -e ftrace:function ls
Allowed only for root.
Link: http://lkml.kernel.org/r/1329317514-8131-6-git-send-email-jolsa@redhat.com
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Adding FTRACE_ENTRY_REG macro so particular ftrace entries
could specify registration function and thus become accesible
via perf.
This will be used in upcomming patch for function trace.
Link: http://lkml.kernel.org/r/1329317514-8131-5-git-send-email-jolsa@redhat.com
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Adding TRACE_REG_PERF_ADD and TRACE_REG_PERF_DEL to handle
perf event schedule in/out actions.
The add action is invoked for when the perf event is scheduled in,
while the del action is invoked when the event is scheduled out.
Link: http://lkml.kernel.org/r/1329317514-8131-4-git-send-email-jolsa@redhat.com
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Adding TRACE_REG_PERF_OPEN and TRACE_REG_PERF_CLOSE to differentiate
register/unregister from open/close actions.
The register/unregister actions are invoked for the first/last
tracepoint user when opening/closing the event.
The open/close actions are invoked for each tracepoint user when
opening/closing the event.
Link: http://lkml.kernel.org/r/1329317514-8131-3-git-send-email-jolsa@redhat.com
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Adding a way to temporarily enable/disable ftrace_ops. The change
follows the same way as 'global' ftrace_ops are done.
Introducing 2 global ftrace_ops - control_ops and ftrace_control_list
which take over all ftrace_ops registered with FTRACE_OPS_FL_CONTROL
flag. In addition new per cpu flag called 'disabled' is also added to
ftrace_ops to provide the control information for each cpu.
When ftrace_ops with FTRACE_OPS_FL_CONTROL is registered, it is
set as disabled for all cpus.
The ftrace_control_list contains all the registered 'control' ftrace_ops.
The control_ops provides function which iterates ftrace_control_list
and does the check for 'disabled' flag on current cpu.
Adding 3 inline functions:
ftrace_function_local_disable/ftrace_function_local_enable
- enable/disable the ftrace_ops on current cpu
ftrace_function_local_disabled
- get disabled ftrace_ops::disabled value for current cpu
Link: http://lkml.kernel.org/r/1329317514-8131-2-git-send-email-jolsa@redhat.com
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If more than one __print_*() function is used in a tracepoint
(__print_flags(), __print_symbols(), etc), then the temp seq buffer will
not be zero on entry. Using the temp seq buffer's length to know if
data has been printed or not in the current function is incorrect and
may produce incorrect results.
Currently, no in-tree tracepoint causes this bug, but new ones may
be created.
Cc: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If __print_flags() is used after another __print_*() function, the
temp seq_file buffer will not be empty on entry, and the delimiter will
be printed even though there's just one field. We get something like:
|S
instead of just:
S
This is because the length of the temp seq buffer is used to determine
if the delimiter is printed or not. But this algorithm fails when
the seq buffer is not empty on entry, and the delimiter will be printed
because it thinks that a previous field was already printed.
Link: http://lkml.kernel.org/r/1329650167-480655-1-git-send-email-avagin@openvz.org
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Assorted fixes, sat in -next for a week or so...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
ocfs2: deal with wraparounds of i_nlink in ocfs2_rename()
vfs: fix compat_sys_stat() handling of overflows in st_nlink
quota: Fix deadlock with suspend and quotas
vfs: Provide function to get superblock and wait for it to thaw
vfs: fix panic in __d_lookup() with high dentry hashtable counts
autofs4 - fix lockdep splat in autofs
vfs: fix d_inode_lookup() dentry ref leak
Add helper functions to read and write struct timeval and struct
timespec from userspace. We already had helper functions for reading
and writing struct compat_timespec; add a set of functions to do the
same with struct timeval, and add a second suite of functions which
can be sensitive to COMPAT_USE_64BIT_TIME and access either 32- or
64-bit time structures.
This also exports these helper functions to modules.
Rename the existing inlines for converting between struct
compat_timeval and native struct timespec so we can have a saner
naming convention for the exported functions.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Replace the fd_sets in struct fdtable with an array of unsigned longs and then
use the standard non-atomic bit operations rather than the FD_* macros.
This:
(1) Removes the abuses of struct fd_set:
(a) Since we don't want to allocate a full fd_set the vast majority of the
time, we actually, in effect, just allocate a just-big-enough array of
unsigned longs and cast it to an fd_set type - so why bother with the
fd_set at all?
(b) Some places outside of the core fdtable handling code (such as
SELinux) want to look inside the array of unsigned longs hidden inside
the fd_set struct for more efficient iteration over the entire set.
(2) Eliminates the use of FD_*() macros in the kernel completely.
(3) Permits the __FD_*() macros to be deleted entirely where not exposed to
userspace.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: http://lkml.kernel.org/r/20120216174954.23314.48147.stgit@warthog.procyon.org.uk
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Print physical address info in a style consistent with the %pR style used
elsewhere in the kernel.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Since suspend_stats_update() is only called from pm_suspend(),
move its code directly into that function and remove the static
inline definition from include/linux/suspend.h. Clean_up
pm_suspend() in the process.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
The enter_state() function in kernel/power/suspend.c should be
static and state_store() in kernel/power/suspend.c should call
pm_suspend() instead of it, so make that happen (which also reduces
code duplication related to suspend statistics).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
The kerneldoc comments in kernel/power/suspend.c are not formatted
in the same way and the quality of some of them is questionable.
Unify the formatting and improve the contents.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Make irq_domain_ops pointer a constant to make it safer for multiple
instances to share the same ops pointer and change the irq_domain code
so that it does not modify the ops.
v4: Fix mismatched type reference in powerpc code
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
Rather than having each interrupt controller driver creating its own barely
unique .xlate function for irq_domain, create a library of translators which
any driver can use directly.
v5: - Remove irq_domain_xlate_pci(). It was incorrect.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
irq_domain_add_simple() was a stop-gap measure until complete irq_domain
support was complete. This patch removes the irq_domain_add_simple()
interface.
This patch also drops the explicit irq_domain initialization performed
by the mach-versatile code because the versatile interrupt controller
already has irq_domain support built into it. This was a bug that was
hanging around quietly for a while, but with the full irq_domain which
actually verifies that irq_domain ranges are available it would cause
the registration to fail and the system wouldn't boot.
v4: Fixed number of irqs in mx5 gpio code
v2: Updated to pass in host_data pointer on irq_domain allocation.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Cc: Russell King <linux@arm.linux.org.uk>
Tested-by: Olof Johansson <olof@lixom.net>
This patch removes the simplistic implementation of irq_domains and enables
the powerpc infrastructure for all irq_domain users. The powerpc
infrastructure includes support for complex mappings between Linux and
hardware irq numbers, and can manage allocation of irq_descs.
This patch also converts the few users of irq_domain_add()/irq_domain_del()
to call irq_domain_add_legacy() instead.
v3: Fix bug that set up too many irqs in translation range.
v2: Fix removal of irq_alloc_descs() call in gic driver
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
Add support for a legacy mapping where irq = (hwirq - first_hwirq + first_irq)
so that a controller driver can allocate a fixed range of irq_descs and use
a simple calculation to translate back and forth between linux and hw irq
numbers. This is needed to use an irq_domain with many of the ARM interrupt
controller drivers that manage their own irq_desc allocations. Ultimately
the goal is to migrate those drivers to use the linear revmap, but doing it
this way allows each driver to be converted separately which makes the
migration path easier.
This patch generalizes the IRQ_DOMAIN_MAP_LEGACY method to use
(first_irq-first_hwirq) as the offset between hwirq and linux irq number,
and adds checks to make sure that the hwirq number does not exceed range
assigned to the controller.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
Each revmap type has different arguments for setting up the revmap.
This patch splits up the generator functions so that each revmap type
can do its own setup and the user doesn't need to keep track of how
each revmap type handles the arguments.
This patch also adds a host_data argument to the generators. There are
cases where the host_data pointer will be needed before the function returns.
ie. the legacy map calls the .map callback for each irq before returning.
v2: - Add void *host_data argument to irq_domain_add_*() functions
- fixed failure to compile
- Moved IRQ_DOMAIN_MAP_* defines into irqdomain.c
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
No functional changes. Replaces non-exported references to 'host' with domain.
Does not change any symbol names referenced by other .c files.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
zero always means no irq when using irq domains. Get rid of the NO_IRQ
references.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
This patch only moves the code. It doesn't make any changes, and the
code is still only compiled for powerpc. Follow-on patches will generalize
the code for other architectures.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
idle_cpu() is called on irq entry to guess if we need to call
tick_check_idle(). This way we can catch up with jiffies if the tick
was stopped, stop accounting idle time during the interrupt and
maintain the sched clock if it is unstable.
But if we are going to exit the idle loop to schedule a new task (ie:
if we have a task in the runqueue or a remotely enqueued ttwu to
perform), the idle_cpu() check will return 0 such that we miss the
call to tick_check_idle() for all interrupts happening before we
schedule the new task.
As a result these interrupts and the softirqs coming along may deal
with stale jiffies values, bad sched clock values, and won't substract
their time from the idle time accounting.
Fix this with using is_idle_task() instead that strictly checks that
we are running the idle task, without caring about the fact we are
going to schedule a task soon.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Ingo Molnar <mingo@elte.hu>
Link: http://lkml.kernel.org/r/1327427984-23282-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
ts->inidle is set by tick_nohz_idle_enter() and unset by
tick_nohz_idle_exit(). However these two calls are assumed
to be always paired. This means that by the time we call
tick_nohz_idle_exit(), ts->inidle is supposed to be always
set to 1.
Remove the checks for ts->inidle in tick_nohz_idle_exit().
This simplifies a bit the code and improves its debuggability
(ie: ensure the call is paired with a tick_nohz_idle_enter()
call).
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Ingo Molnar <mingo@elte.hu>
Link: http://lkml.kernel.org/r/1327427984-23282-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There is no reason to call update_ts_time_stat from tick_nohz_start_idle
anymore (after e0e37c20 sched: Eliminate the ts->idle_lastupdate field)
when we updated idle_lastupdate unconditionally.
We haven't set idle_active yet and do not provide last_update_time so
the whole call end up being just 2 wasted branches.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Link: http://lkml.kernel.org/r/1322755222-6951-1-git-send-email-mhocko@suse.cz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Platforms with Always Running APIC Timer doesn't use the broadcast timer
but the kernel is leaving the broadcast timer (HPET in this case)
in oneshot mode.
On these platforms, before the switch to oneshot mode, broadcast device is
actually in shutdown mode. Code checks for empty tick_broadcast_mask and
avoids going into the periodic mode.
During switch to oneshot mode, add the same tick_broadcast_mask checks in the
tick_broadcast_switch_to_oneshot() and avoid the broadcast device going into
the oneshot mode.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: john stultz <johnstul@us.ibm.com>
Cc: venki@google.com
Link: http://lkml.kernel.org/r/1320452301.15071.16.camel@sbsiddha-desk.sc.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
No need to assign ret in each case and break. Simply return the result
of the handler function directly.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@linux.intel.com>
Some of the newer futex PI opcodes do not check the cmpxchg enabled
variable and call unconditionally into the handling functions. Cover
all PI opcodes in a separate check.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@linux.intel.com>
An interrupt might be pending when irq_startup() is called, but the
startup code does not invoke the resend logic. In some cases this
prevents the device from issuing another interrupt which renders the
device non functional.
Call the resend function in irq_startup() to keep things going.
Reported-and-tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When the primary handler of an interrupt which is marked IRQ_ONESHOT
returns IRQ_HANDLED or IRQ_NONE, then the interrupt thread is not
woken and the unmask logic of the interrupt line is never
invoked. This keeps the interrupt masked forever.
This was not noticed as most IRQ_ONESHOT users wake the thread
unconditionally (usually because they cannot access the underlying
device from hard interrupt context). Though this behaviour was nowhere
documented and not necessarily intentional. Some drivers can avoid the
thread wakeup in certain cases and run into the situation where the
interrupt line s kept masked.
Handle it gracefully.
Reported-and-tested-by: Lothar Wassmann <lw@karo-electronics.de>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Part of the series to unify the irq remapping mechanisms in the
kernel. A follow up patch will copy the powerpc implementation into
kernel/irq/irqdomain.c, which will be a lot easier if the structures
are identical.
Where they differ, I've chose to use the powerpc names since there is
a lot more code using those names.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
irq_domain printk's too much. Drop some output.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Olof Johansson <olof@lixom.net>
When the number of dentry cache hash table entries gets too high
(2147483648 entries), as happens by default on a 16TB system, use of a
signed integer in the dcache_init() initialization loop prevents the
dentry_hashtable from getting initialized, causing a panic in
__d_lookup(). Fix this in dcache_init() and similar areas.
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Allow bint param accept nul values, just do same as bool param.
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Collapse security_vm_enough_memory() variants into a single function.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>
The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.
The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107
Link: http://lkml.kernel.org/r/1322600880.1534.347.camel@localhost.localdomain
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add a printk.console trace point to record any printk
messages into the trace, regardless of the current
console loglevel. This can help correlate (existing)
printk debugging with other tracing.
Link: http://lkml.kernel.org/r/1322161388.5366.54.camel@jlt3.sipsolutions.net
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The Finish label in suspend_freeze_processes() is in fact unnecessary
and makes the function look more complicated than it really is, so
remove that label (along with a few empty lines).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Use the observation that it is more efficient to check the wakeup
variable once before the loop reporting tasks that were not
frozen in try_to_freeze_tasks() than to do that in every step of that
loop.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The PM QoS feature originally didn't depend on CONFIG_PM, which was
mistakenly changed by commit e8db0be124
PM QoS: Move and rename the implementation files
Later, commit d020283dc6
PM / QoS: CPU C-state breakage with PM Qos change
partially fixed that by introducing a static inline definition of
pm_qos_request(), but that still didn't allow user space to use
the PM QoS interface if CONFIG_PM was unset (which had been possible
before). For this reason, remove the dependency of PM QoS on
CONFIG_PM to make it work (as intended) with CONFIG_PM unset.
[rjw: Replaced the original changelog with a new one.]
Signed-off-by: Jean Pihet <j-pihet@ti.com>
Reported-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Actually, sched_switch function tracer is merged into wakeup/wakeup_rt
Update 'mini-HOWTO' for ftrace(Kernel function tracer).
If we want to trace "sched:sched_switch" to trace sched_switch func,
We may utilize event option.(e.g: trace-cmd list -e | grep sched)
This patch is based on Linux-3.3.rc2-SMP-PREEMPT
Link: http://lkml.kernel.org/r/1328695537-15081-1-git-send-email-geunsik.lim@gmail.com
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Geunsik Lim <geunsik.lim@samsung.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Says Jens:
"Time to push off some of the pending items. I really wanted to wait
until we had the regression nailed, but alas it's not quite there yet.
But I'm very confident that it's "just" a missing expire on exit, so
fix from Tejun should be fairly trivial. I'm headed out for a week on
the slopes.
- Killing the barrier part of mtip32xx. It doesn't really support
barriers, and it doesn't need them (writes are fully ordered).
- A few fixes from Dan Carpenter, preventing overflows of integer
multiplication.
- A fixup for loop, fixing a previous commit that didn't quite solve
the partial read problem from Dave Young.
- A bio integer overflow fix from Kent Overstreet.
- Improvement/fix of the door "keep locked" part of the cdrom shared
code from Paolo Benzini.
- A few cfq fixes from Shaohua Li.
- A fix for bsg sysfs warning when removing a file it did not create
from Stanislaw Gruszka.
- Two fixes for floppy from Vivek, preventing a crash.
- A few block core fixes from Tejun. One killing the over-optimized
ioc exit path, cleaning that up nicely. Two others fixing an oops
on elevator switch, due to calling into the scheduler merge check
code without holding the queue lock."
* 'for-linus' of git://git.kernel.dk/linux-block:
block: fix lockdep warning on io_context release put_io_context()
relay: prevent integer overflow in relay_open()
loop: zero fill bio instead of return -EIO for partial read
bio: don't overflow in bio_get_nr_vecs()
floppy: Fix a crash during rmmod
floppy: Cleanup disk->queue before caling put_disk() if add_disk() was never called
cdrom: move shared static to cdrom_device_info
bsg: fix sysfs link remove warning
block: don't call elevator callbacks for plug merges
block: separate out blk_rq_merge_ok() and blk_try_merge() from elevator functions
mtip32xx: removed the irrelevant argument of mtip_hw_submit_io() and the unused member of struct driver_data
block: strip out locking optimization in put_io_context()
cdrom: use copy_to_user() without the underscores
block: fix ioc locking warning
block: fix NULL icq_cache reference
block,cfq: change code order
Reflect the change in the soft and hard lockup thresholds and
their relation to the frequency of the hrtimer and NMI events in
the code comments. While at it, remove references to files that
do not exist anymore.
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/r/1328827342-6253-3-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix double start/stop in x86_pmu_start()
perf evsel: Fix an issue where perf report fails to show the proper percentage
perf tools: Fix prefix matching for kernel maps
perf tools: Fix perf stack to non executable on x86_64
perf: Remove deprecated WARN_ON_ONCE()
"subbuf_size" and "n_subbufs" come from the user and they need to be
capped to prevent an integer overflow.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The code related to 'freezer_test_done' is needlessly convoluted.
Refactor the code and simplify the implementation.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
In the hibernation call path, the kernel threads are frozen inside
hibernation_snapshot(). If we happen to encounter an error further down
the road or if we are exiting early due to a successful freezer test,
then thaw kernel threads before returning to the caller.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The code
if (error) {
suspend_stats.fail++;
dpm_save_failed_errno(error);
} else
suspend_stats.success++;
Appears in the kernel/power/main.c and kernel/power/suspend.c.
This patch just creates a new function to avoid duplicated code.
Suggested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Marcos Paulo de Souza <marcos.mage@gmail.com>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The current LSM interface to cred_free is not sufficient for allowing
an LSM to track the life and death of a task. This patch adds the
task_free hook so that an LSM can clean up resources on task death.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <jmorris@namei.org>
The following patch fixes a bug introduced by the following
commit:
e050e3f0a7 ("perf: Fix broken interrupt rate throttling")
The patch caused the following warning to pop up depending on
the sampling frequency adjustments:
------------[ cut here ]------------
WARNING: at arch/x86/kernel/cpu/perf_event.c:995 x86_pmu_start+0x79/0xd4()
It was caused by the following call sequence:
perf_adjust_freq_unthr_context.part() {
stop()
if (delta > 0) {
perf_adjust_period() {
if (period > 8*...) {
stop()
...
start()
}
}
}
start()
}
Which caused a double start and a double stop, thus triggering
the assert in x86_pmu_start().
The patch fixes the problem by avoiding the double calls. We
pass a new argument to perf_adjust_period() to indicate whether
or not the event is already stopped. We can't just remove the
start/stop from that function because it's called from
__perf_event_overflow where the event needs to be reloaded via a
stop/start back-toback call.
The patch reintroduces the assertion in x86_pmu_start() which
was removed by commit:
84f2b9b ("perf: Remove deprecated WARN_ON_ONCE()")
In this second version, we've added calls to disable/enable PMU
during unthrottling or frequency adjustment based on bug report
of spurious NMI interrupts from Eric Dumazet.
Reported-and-tested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: markus@trippelsdorf.de
Cc: paulus@samba.org
Link: http://lkml.kernel.org/r/20120207133956.GA4932@quad
[ Minor edits to the changelog and to the code ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
put_io_context() performed a complex trylock dancing to avoid
deferring ioc release to workqueue. It was also broken on UP because
trylock was always assumed to succeed which resulted in unbalanced
preemption count.
While there are ways to fix the UP breakage, even the most
pathological microbench (forced ioc allocation and tight fork/exit
loop) fails to show any appreciable performance benefit of the
optimization. Strip it out. If there turns out to be workloads which
are affected by this change, simpler optimization from the discussion
thread can be applied later.
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <1328514611.21268.66.camel@sli10-conroe>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
So that we can get the perf bench exec stack fixes and then apply the
remaining fix for the files added after what is in perf/urgent.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Three power management regression fixes, one for a recent regression introcuded
by the freezer changes during the 3.3 merge window and two for regressions
in cpuidle (resulting from PM QoS changes) and in the hibernate user space
interface, both introduced during the 3.2 development cycle.
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Merge tag 'pm-fixes-for-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Power management fixes for 3.3-rc3
Three power management regression fixes, one for a recent regression introcuded
by the freezer changes during the 3.3 merge window and two for regressions
in cpuidle (resulting from PM QoS changes) and in the hibernate user space
interface, both introduced during the 3.2 development cycle.
They include:
* Two hibernate (s2disk) regression fixes from Srivatsa S. Bhat (for
regressions introduced during the 3.3 merge window and during the 3.2
development cycle).
* A cpuidle fix from Venki Pallipadi for a regression resulting from PM QoS
changes during the 3.2 development cycle causing cpuidle to work incorrectly
for CONFIG_PM unset.
* tag 'pm-fixes-for-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / QoS: CPU C-state breakage with PM Qos change
PM / Freezer: Thaw only kernel threads if freezing of kernel threads fails
PM / Hibernate: Thaw kernel threads in SNAPSHOT_CREATE_IMAGE ioctl path
If freezing of kernel threads fails, we are expected to automatically
thaw tasks in the error recovery path. However, at times, we encounter
situations in which we would like the automatic error recovery path
to thaw only the kernel threads, because we want to be able to do
some more cleanup before we thaw userspace. Something like:
error = freeze_kernel_threads();
if (error) {
/* Do some cleanup */
/* Only then thaw userspace tasks*/
thaw_processes();
}
An example of such a situation is where we freeze/thaw filesystems
during suspend/hibernation. There, if freezing of kernel threads
fails, we would like to thaw the frozen filesystems before thawing
the userspace tasks.
So, modify freeze_kernel_threads() to thaw only kernel threads in
case of freezing failure. And change suspend_freeze_processes()
accordingly. (At the same time, let us also get rid of the rather
cryptic usage of the conditional operator (:?) in that function.)
[rjw: In fact, this patch fixes a regression introduced during the
3.3 merge window, because without it thaw_processes() may be called
before swsusp_free() in some situations and that may lead to massive
memory allocation failures.]
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Nigel Cunningham <nigel@tuxonice.net>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
In function pre_handler_kretprobe(), the allocated kretprobe_instance
object will get leaked if the entry_handler callback returns non-zero.
This may cause all the preallocated kretprobe_instance objects exhausted.
This issue can be reproduced by changing
samples/kprobes/kretprobe_example.c to probe "mutex_unlock". And the fix
is straightforward: just put the allocated kretprobe_instance object back
onto the free_instances list.
[akpm@linux-foundation.org: use raw_spin_lock/unlock]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
EXPORT_SYMBOL(adjust_resource) should be right after adjust_resource().
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The __raise_softirq_irqoff() contains a tracepoint. As tracepoints in headers
can cause issues, and not to mention, bloats the kernel when they are
in a static inline, it is best to move the function that contains the
tracepoint out of the header and into softirq.c.
Link: http://lkml.kernel.org/r/20120118120711.GB14863@elte.hu
Suggested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently the ftrace_set_filter and ftrace_set_notrace functions
do not return any return code. So there's no way for ftrace_ops
user to tell wether the filter was correctly applied.
The set_ftrace_filter interface returns error in case the filter
did not match:
# echo krava > set_ftrace_filter
bash: echo: write error: Invalid argument
Changing both ftrace_set_filter and ftrace_set_notrace functions
to return zero if the filter was applied correctly or -E* values
in case of error.
Link: http://lkml.kernel.org/r/1325495060-6402-2-git-send-email-jolsa@redhat.com
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As noted by Arve and others, since wall time can jump backwards, it is
difficult to use for input because one cannot determine if one event
occurred before another or for how long a key was pressed.
However, the timestamp field is part of the kernel ABI, and cannot be
changed without possibly breaking existing users.
This patch adds a new IOCTL that allows a clockid to be set in the
evdev_client struct that will specify which time base to use for event
timestamps (ie: CLOCK_MONOTONIC instead of CLOCK_REALTIME).
For now we only support CLOCK_MONOTONIC and CLOCK_REALTIME, but
in the future we could support other clockids if appropriate.
The default remains CLOCK_REALTIME, so we don't change the ABI.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Daniel Kurtz <djkurtz@google.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This fixes the race in process_vm_core found by Oleg (see
http://article.gmane.org/gmane.linux.kernel/1235667/
for details).
This has been updated since I last sent it as the creation of the new
mm_access() function did almost exactly the same thing as parts of the
previous version of this patch did.
In order to use mm_access() even when /proc isn't enabled, we move it to
kernel/fork.c where other related process mm access functions already
are.
Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
bugs, x86: Fix printk levels for panic, softlockups and stack dumps
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf top: Fix number of samples displayed
perf tools: Fix strlen() bug in perf_event__synthesize_event_type()
perf tools: Fix broken build by defining _GNU_SOURCE in Makefile
x86/dumpstack: Remove unneeded check in dump_trace()
perf: Fix broken interrupt rate throttling
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/rt: Fix task stack corruption under __ARCH_WANT_INTERRUPTS_ON_CTXSW
sched: Fix ancient race in do_exit()
sched/nohz: Fix nohz cpu idle load balancing state with cpu hotplug
sched/s390: Fix compile error in sched/core.c
sched: Fix rq->nr_uninterruptible update race
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/reboot: Remove VersaLogic Menlow reboot quirk
x86/reboot: Skip DMI checks if reboot set by user
x86: Properly parenthesize cmpxchg() macro arguments
The argument is not used at all, and it's not necessary, because
a specific callback handler of course knows which subsys it
belongs to.
Now only ->pupulate() takes this argument, because the handlers of
this callback always call cgroup_add_file()/cgroup_add_files().
So we reduce a few lines of code, though the shrinking of object size
is minimal.
16 files changed, 113 insertions(+), 162 deletions(-)
text data bss dec hex filename
5486240 656987 7039960 13183187 c928d3 vmlinux.o.orig
5486170 656987 7039960 13183117 c9288d vmlinux.o
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
In the SNAPSHOT_CREATE_IMAGE ioctl, if the call to hibernation_snapshot()
fails, the frozen tasks are not thawed.
And in the case of success, if we happen to exit due to a successful freezer
test, all tasks (including those of userspace) are thawed, whereas actually
we should have thawed only the kernel threads at that point. Fix both these
issues.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@vger.kernel.org
This also fixes the following compilation warning on !SMP:
CC kernel/sched/fair.o
kernel/sched/fair.c:218:36: warning: 'max_load_balance_interval' defined but not used [-Wunused-variable]
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4F2754A0.9090306@ct.jp.nec.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In cgroup_attach_proc, we indirectly call find_existing_css_set 3
times. It is an expensive call so we want to call it a minimum
of times. This patch only calls it once and stores the result so
that it can be used later on when we call cgroup_task_migrate.
This required modifying cgroup_task_migrate to take the new css_set
(which we obtained from find_css_set) as a parameter. The nice side
effect of this is that cgroup_task_migrate is now identical for
cgroup_attach_task and cgroup_attach_proc. It also now returns a
void since it can never fail.
Changes in V5:
* https://lkml.org/lkml/2012/1/20/344 (Tejun Heo)
* Remove css_set_refs
Changes in V4:
* https://lkml.org/lkml/2011/12/22/421 (Li Zefan)
* Avoid GFP_KERNEL (sleep) in rcu_read_lock by getting css_set in
a separate loop not under an rcu_read_lock
Changes in V3:
* https://lkml.org/lkml/2011/12/22/13 (Li Zefan)
* Fixed earlier bug by creating a seperate patch to remove tasklist_lock
Changes in V2:
* https://lkml.org/lkml/2011/12/20/372 (Tejun Heo)
* Move find_css_set call into loop which creates the flex array
* Author
* Kill css_set_refs and use group_size instead
* Fix an off-by-one error in counting css_set refs
* Add a retval check in out_list_teardown
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: containers@lists.linux-foundation.org
Cc: cgroups@vger.kernel.org
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>
- Replace class ID #define with enumeration
- Loop through PM QoS objects during initialization (rather than
initializing them one-by-one)
Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-by: Antti Miettinen <amiettinen@nvidia.com>
Reviewed-by: Diwakar Tundlam <dtundlam@nvidia.com>
Reviewed-by: Scott Williams <scwilliams@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>
Acked-by: markgross <markgross@thegnar.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The current device suspend/resume phases during system-wide power
transitions appear to be insufficient for some platforms that want
to use the same callback routines for saving device states and
related operations during runtime suspend/resume as well as during
system suspend/resume. In principle, they could point their
.suspend_noirq() and .resume_noirq() to the same callback routines
as their .runtime_suspend() and .runtime_resume(), respectively,
but at least some of them require device interrupts to be enabled
while the code in those routines is running.
It also makes sense to have device suspend-resume callbacks that will
be executed with runtime PM disabled and with device interrupts
enabled in case someone needs to run some special code in that
context during system-wide power transitions.
Apart from this, .suspend_noirq() and .resume_noirq() were introduced
as a workaround for drivers using shared interrupts and failing to
prevent their interrupt handlers from accessing suspended hardware.
It appears to be better not to use them for other porposes, or we may
have to deal with some serious confusion (which seems to be happening
already).
For the above reasons, introduce new device suspend/resume phases,
"late suspend" and "early resume" (and analogously for hibernation)
whose callback will be executed with runtime PM disabled and with
device interrupts enabled and whose callback pointers generally may
point to runtime suspend/resume routines.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Commit 2aede851dd
PM / Hibernate: Freeze kernel threads after preallocating memory
introduced a mechanism by which kernel threads were frozen after
the preallocation of hibernate image memory to avoid problems with
frozen kernel threads not responding to memory freeing requests.
However, it overlooked the s2disk code path in which the
SNAPSHOT_CREATE_IMAGE ioctl was run directly after SNAPSHOT_FREE,
which caused freeze_workqueues_begin() to BUG(), because it saw
that worqueues had been already frozen.
Although in principle this issue might be addressed by removing
the relevant BUG_ON() from freeze_workqueues_begin(), that would
reintroduce the very problem that commit 2aede851dd
attempted to avoid into that particular code path. For this reason,
to fix the issue at hand, introduce thaw_kernel_threads() and make
the SNAPSHOT_FREE ioctl execute it.
Special thanks to Srivatsa S. Bhat for detailed analysis of the
problem.
Reported-and-tested-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: stable@kernel.org
Currently we don't utilize the sched_switch field anymore.
But, simply removing sched_switch field from the middle of the
sched_stat output will break tools.
So, to stay compatible we hardcode it to zero and remove the
field from the scheduler data structures.
Update the schedstat documentation accordingly.
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1327422836.27181.5.camel@localhost.localdomain
Signed-off-by: Ingo Molnar <mingo@elte.hu>
With a lot of small tasks, the softirq sched is nearly never called
when no_hz is enabled. In this case load_balance() is mainly called
with the newly_idle mode which doesn't update the cpu_power.
Add a next_update field which ensure a maximum update period when
there is short activity.
Having stale cpu_power information can skew the load-balancing
decisions, this is cured by the guaranteed update.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323717668-2143-1-git-send-email-vincent.guittot@linaro.org
The block layer has some code trying to determine if two CPUs share a
cache, the scheduler has a similar function. Expose the function used
by the scheduler and make the block layer use it, thereby removing the
block layers usage of CONFIG_SCHED* and topology bits.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Jens Axboe <axboe@kernel.dk>
Link: http://lkml.kernel.org/r/1327579450.2446.95.camel@twins
This issue happens under the following conditions:
1. preemption is off
2. __ARCH_WANT_INTERRUPTS_ON_CTXSW is defined
3. RT scheduling class
4. SMP system
Sequence is as follows:
1.suppose current task is A. start schedule()
2.task A is enqueued pushable task at the entry of schedule()
__schedule
prev = rq->curr;
...
put_prev_task
put_prev_task_rt
enqueue_pushable_task
4.pick the task B as next task.
next = pick_next_task(rq);
3.rq->curr set to task B and context_switch is started.
rq->curr = next;
4.At the entry of context_swtich, release this cpu's rq->lock.
context_switch
prepare_task_switch
prepare_lock_switch
raw_spin_unlock_irq(&rq->lock);
5.Shortly after rq->lock is released, interrupt is occurred and start IRQ context
6.try_to_wake_up() which called by ISR acquires rq->lock
try_to_wake_up
ttwu_remote
rq = __task_rq_lock(p)
ttwu_do_wakeup(rq, p, wake_flags);
task_woken_rt
7.push_rt_task picks the task A which is enqueued before.
task_woken_rt
push_rt_tasks(rq)
next_task = pick_next_pushable_task(rq)
8.At find_lock_lowest_rq(), If double_lock_balance() returns 0,
lowest_rq can be the remote rq.
(But,If preemption is on, double_lock_balance always return 1 and it
does't happen.)
push_rt_task
find_lock_lowest_rq
if (double_lock_balance(rq, lowest_rq))..
9.find_lock_lowest_rq return the available rq. task A is migrated to
the remote cpu/rq.
push_rt_task
...
deactivate_task(rq, next_task, 0);
set_task_cpu(next_task, lowest_rq->cpu);
activate_task(lowest_rq, next_task, 0);
10. But, task A is on irq context at this cpu.
So, task A is scheduled by two cpus at the same time until restore from IRQ.
Task A's stack is corrupted.
To fix it, don't migrate an RT task if it's still running.
Signed-off-by: Chanho Min <chanho.min@lge.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/CAOAMb1BHA=5fm7KTewYyke6u-8DP0iUuJMpgQw54vNeXFsGpoQ@mail.gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch fixes the sampling interrupt throttling mechanism.
It was broken in v3.2. Events were not being unthrottled. The
unthrottling mechanism required that events be checked at each
timer tick.
This patch solves this problem and also separates:
- unthrottling
- multiplexing
- frequency-mode period adjustments
Not all of them need to be executed at each timer tick.
This third version of the patch is based on my original patch +
PeterZ proposal (https://lkml.org/lkml/2012/1/7/87).
At each timer tick, for each context:
- if the current CPU has throttled events, we unthrottle events
- if context has frequency-based events, we adjust sampling periods
- if we have reached the jiffies interval, we multiplex (rotate)
We decoupled rotation (multiplexing) from frequency-mode sampling
period adjustments. They should not necessarily happen at the same
rate. Multiplexing is subject to jiffies_interval (currently at 1
but could be higher once the tunable is exposed via sysfs).
We have grouped frequency-mode adjustment and unthrottling into the
same routine to minimize code duplication. When throttled while in
frequency mode, we scan the events only once.
We have fixed the threshold enforcement code in __perf_event_overflow().
There was a bug whereby it would allow more than the authorized rate
because an increment of hwc->interrupts was not executed at the right
place.
The patch was tested with low sampling limit (2000) and fixed periods,
frequency mode, overcommitted PMU.
On a 2.1GHz AMD CPU:
$ cat /proc/sys/kernel/perf_event_max_sample_rate
2000
We set a rate of 3000 samples/sec (2.1GHz/3000 = 700000):
$ perf record -e cycles,cycles -c 700000 noploop 10
$ perf report -D | tail -21
Aggregated stats:
TOTAL events: 80086
MMAP events: 88
COMM events: 2
EXIT events: 4
THROTTLE events: 19996
UNTHROTTLE events: 19996
SAMPLE events: 40000
cycles stats:
TOTAL events: 40006
MMAP events: 5
COMM events: 1
EXIT events: 4
THROTTLE events: 9998
UNTHROTTLE events: 9998
SAMPLE events: 20000
cycles stats:
TOTAL events: 39996
THROTTLE events: 9998
UNTHROTTLE events: 9998
SAMPLE events: 20000
For 10s, the cap is 2x2000x10 = 40000 samples.
We get exactly that: 20000 samples/event.
Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: <stable@kernel.org> # v3.2+
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120126160319.GA5655@quad
Signed-off-by: Ingo Molnar <mingo@elte.hu>
try_to_wake_up() has a problem which may change status from TASK_DEAD to
TASK_RUNNING in race condition with SMI or guest environment of virtual
machine. As a result, exited task is scheduled() again and panic occurs.
Here is the sequence how it occurs:
----------------------------------+-----------------------------
|
CPU A | CPU B
----------------------------------+-----------------------------
TASK A calls exit()....
do_exit()
exit_mm()
down_read(mm->mmap_sem);
rwsem_down_failed_common()
set TASK_UNINTERRUPTIBLE
set waiter.task <= task A
list_add to sem->wait_list
:
raw_spin_unlock_irq()
(I/O interruption occured)
__rwsem_do_wake(mmap_sem)
list_del(&waiter->list);
waiter->task = NULL
wake_up_process(task A)
try_to_wake_up()
(task is still
TASK_UNINTERRUPTIBLE)
p->on_rq is still 1.)
ttwu_do_wakeup()
(*A)
:
(I/O interruption handler finished)
if (!waiter.task)
schedule() is not called
due to waiter.task is NULL.
tsk->state = TASK_RUNNING
:
check_preempt_curr();
:
task->state = TASK_DEAD
(*B)
<--- set TASK_RUNNING (*C)
schedule()
(exit task is running again)
BUG_ON() is called!
--------------------------------------------------------
The execution time between (*A) and (*B) is usually very short,
because the interruption is disabled, and setting TASK_RUNNING at (*C)
must be executed before setting TASK_DEAD.
HOWEVER, if SMI is interrupted between (*A) and (*B),
(*C) is able to execute AFTER setting TASK_DEAD!
Then, exited task is scheduled again, and BUG_ON() is called....
If the system works on guest system of virtual machine, the time
between (*A) and (*B) may be also long due to scheduling of hypervisor,
and same phenomenon can occur.
By this patch, do_exit() waits for releasing task->pi_lock which is used
in try_to_wake_up(). It guarantees the task becomes TASK_DEAD after
waking up.
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20120117174031.3118.E1E9C6FF@jp.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Keep all the interesting data in a single cache line.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Now that ntp.c's locking is reworked, we can remove most
of the xtime_lock usage in timekeeping.c
The remaining xtime_lock presence is really for jiffies access
and the global load calculation.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Use a ntp_lock spin lock to replace xtime_lock locking in ntp.c
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Currently the NTP managed tick_length value is accessed globally,
in preparations for locking cleanups, make sure it is accessed via
a function and mark it as static.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Move ntp_sycned to ntp.c and mark time_status as static.
Also yank function declaration for non-existant function.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Now that all the timekeeping variables are stored in
the timekeeper structure, add a new lock to protect the
structure.
For now, this lock nests under the xtime_lock for writes.
For readers, we don't need to take xtime_lock anymore.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Move global xtime_lock and timekeeping_suspended values up
to the top of timekeeping.c
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
In preparation for locking cleanups, move raw_time into
timekeeper structure.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
In preparation for locking cleanups, move xtime into
timekeeper structure.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
In preparation for locking cleanups, move wall_to_monotonic
into the timekeeper structure.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Move total_sleep_time into the timekeeper structure in preparation
for locking cleanups
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
rsyslog will display KERN_EMERG messages on a connected
terminal. However, these messages are useless/undecipherable
for a general user.
For example, after a softlockup we get:
Message from syslogd@intel-s3e37-04 at Jan 25 14:18:06 ...
kernel:Stack:
Message from syslogd@intel-s3e37-04 at Jan 25 14:18:06 ...
kernel:Call Trace:
Message from syslogd@intel-s3e37-04 at Jan 25 14:18:06 ...
kernel:Code: ff ff a8 08 75 25 31 d2 48 8d 86 38 e0 ff ff 48 89
d1 0f 01 c8 0f ae f0 48 8b 86 38 e0 ff ff a8 08 75 08 b1 01 4c 89 e0 0f 01 c9 <e8> ea 69 dd ff 4c 29 e8 48 89 c7 e8 0f bc da ff 49 89 c4 49 89
This happens because the printk levels for these messages are
incorrect. Only an informational message should be displayed on
a terminal.
I modified the printk levels for various messages in the kernel
and tested the output by using the drivers/misc/lkdtm.c kernel
modules (ie, softlockups, panics, hard lockups, etc.) and
confirmed that the console output was still the same and that
the output to the terminals was correct.
For example, in the case of a softlockup we now see the much
more informative:
Message from syslogd@intel-s3e37-04 at Jan 25 10:18:06 ...
BUG: soft lockup - CPU4 stuck for 60s!
instead of the above confusing messages.
AFAICT, the messages no longer have to be KERN_EMERG. In the
most important case of a panic we set console_verbose(). As for
the other less severe cases the correct data is output to the
console and /var/log/messages.
Successfully tested by me using the drivers/misc/lkdtm.c module.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: dzickus@redhat.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1327586134-11926-1-git-send-email-prarit@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
With the recent nohz scheduler changes, rq's nohz flag
'NOHZ_TICK_STOPPED' and its associated state doesn't get cleared
immediately after the cpu exits idle. This gets cleared as part
of the next tick seen on that cpu.
For the cpu offline support, we need to clear this state
manually. Fix it by registering a cpu notifier, which clears the
nohz idle load balance state for this rq explicitly during the
CPU_DYING notification.
There won't be any nohz updates for that cpu, after the
CPU_DYING notification. But lets be extra paranoid and skip
updating the nohz state in the select_nohz_load_balancer() if
the cpu is not in active state anymore.
Reported-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Reviewed-and-tested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1327026538.16150.40.camel@sbsiddha-desk.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit 029632fbb7 ("sched: Make
separate sched*.c translation units") removed the include of
asm/mutex.h from sched.c.
This breaks the combination of:
CONFIG_MUTEX_SPIN_ON_OWNER=yes
CONFIG_HAVE_ARCH_MUTEX_CPU_RELAX=yes
like s390 without mutex debugging:
CC kernel/sched/core.o
kernel/sched/core.c: In function ‘mutex_spin_on_owner’:
kernel/sched/core.c:3287: error: implicit declaration of function ‘arch_mutex_cpu_relax’
Lets re-add the include to kernel/sched/core.c
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1326268696-30904-1-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
KOSAKI Motohiro noticed the following race:
> CPU0 CPU1
> --------------------------------------------------------
> deactivate_task()
> task->state = TASK_UNINTERRUPTIBLE;
> activate_task()
> rq->nr_uninterruptible--;
>
> schedule()
> deactivate_task()
> rq->nr_uninterruptible++;
>
Kosaki-San's scenario is possible when CPU0 runs
__sched_setscheduler() against CPU1's current @task.
__sched_setscheduler() does a dequeue/enqueue in order to move
the task to its new queue (position) to reflect the newly provided
scheduling parameters. However it should be completely invariant to
nr_uninterruptible accounting, sched_setscheduler() doesn't affect
readyness to run, merely policy on when to run.
So convert the inappropriate activate/deactivate_task usage to
enqueue/dequeue_task, which avoids the nr_uninterruptible accounting.
Also convert the two other sites: __migrate_task() and
normalize_task() that still use activate/deactivate_task. These sites
aren't really a problem since __migrate_task() will only be called on
non-running task (and therefore are immume to the described problem)
and normalize_task() isn't ever used on regular systems.
Also remove the comments from activate/deactivate_task since they're
misleading at best.
Reported-by: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1327486224.2614.45.camel@laptop
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On ARM, we don't want SPARSE_IRQ to be a user visible option. Make
SPARSE_IRQ visible based on MAY_HAVE_SPARSE_IRQ instead of depending
on HAVE_SPARSE_IRQ.
With this, SPARSE_IRQ is not visible on C6X and ARM.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-sh@vger.kernel.org
Move the core sysctl code from kernel/sysctl.c and kernel/sysctl_check.c
into fs/proc/proc_sysctl.c.
Currently sysctl maintenance is hampered by the sysctl implementation
being split across 3 files with artificial layering between them.
Consolidate the entire sysctl implementation into 1 file so that
it is easier to see what is going on and hopefully allowing for
simpler maintenance.
For functions that are now only used in fs/proc/proc_sysctl.c remove
their declarations from sysctl.h and make them static in fs/proc/proc_sysctl.c
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Simplify the code by treating the base sysctl table like any other
sysctl table and register it with register_sysctl_table.
To ensure this table is registered early enough to avoid problems
call sysctl_init from proc_sys_init.
Rename sysctl_net.c:sysctl_init() to net_sysctl_init() to avoid
name conflicts now that kernel/sysctl.c:sysctl_init() is no longer
static.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
- In sysctl.h move functions only available if CONFIG_SYSCL
is defined inside of #ifdef CONFIG_SYSCTL
- Move the stub function definitions for !CONFIG_SYSCTL
into sysctl.h and make them static inlines.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Davem says:
1) Fix JIT code generation on x86-64 for divide by zero, from Eric Dumazet.
2) tg3 header length computation correction from Eric Dumazet.
3) More build and reference counting fixes for socket memory cgroup
code from Glauber Costa.
4) module.h snuck back into a core header after all the hard work we
did to remove that, from Paul Gortmaker and Jesper Dangaard Brouer.
5) Fix PHY naming regression and add some new PCI IDs in stmmac, from
Alessandro Rubini.
6) Netlink message generation fix in new team driver, should only advertise
the entries that changed during events, from Jiri Pirko.
7) SRIOV VF registration and unregistration fixes, and also add a
missing PCI ID, from Roopa Prabhu.
8) Fix infinite loop in tx queue flush code of brcmsmac, from Stanislaw Gruszka.
9) ftgmac100/ftmac100 build fix, missing interrupt.h include.
10) Memory leak fix in net/hyperv do_set_mutlicast() handling, from Wei Yongjun.
11) Off by one fix in netem packet scheduler, from Vijay Subramanian.
12) TCP loss detection fix from Yuchung Cheng.
13) TCP reset packet MD5 calculation uses wrong address, fix from Shawn Lu.
14) skge carrier assertion and DMA mapping fixes from Stephen Hemminger.
15) Congestion recovery undo performed at the wrong spot in BIC and CUBIC
congestion control modules, fix from Neal Cardwell.
16) Ethtool ETHTOOL_GSSET_INFO is unnecessarily restrictive, from Michał Mirosław.
17) Fix triggerable race in ipv6 sysctl handling, from Francesco Ruggeri.
18) Statistics bug fixes in mlx4 from Eugenia Emantayev.
19) rds locking bug fix during info dumps, from your's truly.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (67 commits)
rds: Make rds_sock_lock BH rather than IRQ safe.
netprio_cgroup.h: dont include module.h from other includes
net: flow_dissector.c missing include linux/export.h
team: send only changed options/ports via netlink
net/hyperv: fix possible memory leak in do_set_multicast()
drivers/net: dsa/mv88e6xxx.c files need linux/module.h
stmmac: added PCI identifiers
llc: Fix race condition in llc_ui_recvmsg
stmmac: fix phy naming inconsistency
dsa: Add reporting of silicon revision for Marvell 88E6123/88E6161/88E6165 switches.
tg3: fix ipv6 header length computation
skge: add byte queue limit support
mv643xx_eth: Add Rx Discard and Rx Overrun statistics
bnx2x: fix compilation error with SOE in fw_dump
bnx2x: handle CHIP_REVISION during init_one
bnx2x: allow user to change ring size in ISCSI SD mode
bnx2x: fix Big-Endianess in ethtool -t
bnx2x: fixed ethtool statistics for MF modes
bnx2x: credit-leakage fixup on vlan_mac_del_all
macvlan: fix a possible use after free
...
Two fixes for regressions introduced during the merge window, one fix for
a long-standing obscure issue in the computation of hibernate image size
and two small PM documentation fixes.
Namhyung Kim (1):
PM / Hibernate: Correct additional pages number calculation
Srivatsa S. Bhat (1):
PM / Hibernate: Rewrite unlock_system_sleep() to fix s2disk regression
Tetsuo Handa (1):
PM / Sleep: Fix read_unlock_usermodehelper() call.
Viresh Kumar (2):
PM / Documentation: Fix spelling mistake in basic-pm-debugging.txt
PM / Documentation: Fix minor issue in freezing_of_tasks.txt
Documentation/power/basic-pm-debugging.txt | 2 +-
Documentation/power/freezing-of-tasks.txt | 8 ++++----
drivers/base/firmware_class.c | 3 +--
include/linux/suspend.h | 19 +++++++++++++++++--
kernel/power/snapshot.c | 3 ++-
5 files changed, 25 insertions(+), 10 deletions(-)
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Merge tag 'pm-fixes-for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Power management fixes for 3.3
Two fixes for regressions introduced during the merge window, one fix for
a long-standing obscure issue in the computation of hibernate image size
and two small PM documentation fixes.
* tag 'pm-fixes-for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / Sleep: Fix read_unlock_usermodehelper() call.
PM / Hibernate: Rewrite unlock_system_sleep() to fix s2disk regression
PM / Hibernate: Correct additional pages number calculation
PM / Documentation: Fix minor issue in freezing_of_tasks.txt
PM / Documentation: Fix spelling mistake in basic-pm-debugging.txt
The usual kernel-doc fixups from Randy. Some of them David acked as
merged in his tree, this is the random left-overs.
* kernel-doc:
docbook: fix sched source file names in device-drivers book
docbook: change iomap source filename in deviceiobook
docbook: don't use serial_core.h in device-drivers book
kernel-doc: fix kernel-doc warnings in sched
kernel-doc: fix new warnings in cfg80211.h
kernel-doc: fix new warning in usb.h
kernel-doc: fix new warnings in device.h
kernel-doc: fix new warnings in debugfs
kernel-doc: fix new warning in regulator core
kernel-doc: fix new warnings in pci
kernel-doc: fix new warnings in driver-core
kernel-doc: fix new warnings in auditsc.c
scripts/kernel-doc: fix fatal error caused by cfg80211.h
Fix new kernel-doc notation warnings:
Warning(include/linux/sched.h:2094): No description found for parameter 'p'
Warning(include/linux/sched.h:2094): Excess function parameter 'tsk' description in 'is_idle_task'
Warning(kernel/sched/cpupri.c:139): No description found for parameter 'newpri'
Warning(kernel/sched/cpupri.c:139): Excess function parameter 'pri' description in 'cpupri_set'
Warning(kernel/sched/cpupri.c:208): Excess function parameter 'bootmem' description in 'cpupri_init'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix new kernel-doc warnings in auditsc.c:
Warning(kernel/auditsc.c:1875): No description found for parameter 'success'
Warning(kernel/auditsc.c:1875): No description found for parameter 'return_code'
Warning(kernel/auditsc.c:1875): Excess function parameter 'pt_regs' description in '__audit_syscall_exit'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit ef53d9c5e ("kprobes: improve kretprobe scalability with hashed
locking") introduced a bug where we can potentially leak
kretprobe_instances since we initialize a hlist head after having used
it.
Initialize the hlist head before using it.
Reported by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srinivasa D S <srinivasa@in.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a case in __sk_mem_schedule(), where an allocation
is beyond the maximum, but yet we are allowed to proceed.
It happens under the following condition:
sk->sk_wmem_queued + size >= sk->sk_sndbuf
The network code won't revert the allocation in this case,
meaning that at some point later it'll try to do it. Since
this is never communicated to the underlying res_counter
code, there is an inbalance in res_counter uncharge operation.
I see two ways of fixing this:
1) storing the information about those allocations somewhere
in memcg, and then deducting from that first, before
we start draining the res_counter,
2) providing a slightly different allocation function for
the res_counter, that matches the original behavior of
the network code more closely.
I decided to go for #2 here, believing it to be more elegant,
since #1 would require us to do basically that, but in a more
obscure way.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
CC: Tejun Heo <tj@kernel.org>
CC: Li Zefan <lizf@cn.fujitsu.com>
CC: Laurent Chavey <chavey@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The perf_event_time() will call perf_cgroup_event_time()
if @event is a cgroup event. Just do it directly and avoid
the extra check..
Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/1327021966-27688-2-git-send-email-namhyung.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When alloc_callchain_buffers() fails, it frees all of
entries before return. In addition, calling the
release_callchain_buffers() will cause a NULL pointer
dereference since callchain_cpu_entries is not set.
Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/1327021966-27688-1-git-send-email-namhyung.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We can replace the tasklist_lock in cgroup_attach_proc with an
rcu_read_lock().
Changes in V4:
* https://lkml.org/lkml/2011/12/23/284 (Frederic Weisbecker)
* Minimize size of rcu_read_lock critical section
* Add comment
* https://lkml.org/lkml/2011/12/26/136 (Li Zefan)
* Split into two patches
Changes in V3:
* https://lkml.org/lkml/2011/12/22/419 (Frederic Weisbecker)
* Add an rcu_read_lock to protect against exit
Changes in V2:
* https://lkml.org/lkml/2011/12/22/86 (Tejun Heo)
* Use a goto instead of returning -EAGAIN
Suggested-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: containers@lists.linux-foundation.org
Cc: cgroups@vger.kernel.org
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>
To keep the complexity of the double-check locking in one place, move
the thread_group_leader check up into attach_task_by_pid(). This
allows us to use a goto instead of returning -EAGAIN.
While at it, convert a couple of returns to gotos and use rcu for the
!pid case also in order to simplify the logic.
Changes in V2:
* https://lkml.org/lkml/2011/12/22/86 (Tejun Heo)
* Use a goto instead of returning -EAGAIN
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: containers@lists.linux-foundation.org
Cc: cgroups@vger.kernel.org
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/accounting, proc: Fix /proc/stat interrupts sum
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tracepoints/module: Fix disabling tracepoints with taint CRAP or OOT
x86/kprobes: Add arch/x86/tools/insn_sanity to .gitignore
x86/kprobes: Fix typo transferred from Intel manual
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, syscall: Need __ARCH_WANT_SYS_IPC for 32 bits
x86, tsc: Fix SMI induced variation in quick_pit_calibrate()
x86, opcode: ANDN and Group 17 in x86-opcode-map.txt
x86/kconfig: Move the ZONE_DMA entry under a menu
x86/UV2: Add accounting for BAU strong nacks
x86/UV2: Ack BAU interrupt earlier
x86/UV2: Remove stale no-resources test for UV2 BAU
x86/UV2: Work around BAU bug
x86/UV2: Fix BAU destination timeout initialization
x86/UV2: Fix new UV2 hardware by using native UV2 broadcast mode
x86: Get rid of dubious one-bit signed bitfield
The struct bm_block is allocated by chain_alloc(),
so it'd better counting it in LINKED_PAGE_DATA_SIZE.
Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit: (29 commits)
audit: no leading space in audit_log_d_path prefix
audit: treat s_id as an untrusted string
audit: fix signedness bug in audit_log_execve_info()
audit: comparison on interprocess fields
audit: implement all object interfield comparisons
audit: allow interfield comparison between gid and ogid
audit: complex interfield comparison helper
audit: allow interfield comparison in audit rules
Kernel: Audit Support For The ARM Platform
audit: do not call audit_getname on error
audit: only allow tasks to set their loginuid if it is -1
audit: remove task argument to audit_set_loginuid
audit: allow audit matching on inode gid
audit: allow matching on obj_uid
audit: remove audit_finish_fork as it can't be called
audit: reject entry,always rules
audit: inline audit_free to simplify the look of generic code
audit: drop audit_set_macxattr as it doesn't do anything
audit: inline checks for not needing to collect aux records
audit: drop some potentially inadvisable likely notations
...
Use evil merge to fix up grammar mistakes in Kconfig file.
Bad speling and horrible grammar (and copious swearing) is to be
expected, but let's keep it to commit messages and comments, rather than
expose it to users in config help texts or printouts.
audit_log_d_path() injects an additional space before the prefix,
which serves no purpose and doesn't mix well with other audit_log*()
functions that do not sneak extra characters into the log.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Eric Paris <eparis@redhat.com>
In the loop, a size_t "len" is used to hold the return value of
audit_log_single_execve_arg(), which returns -1 on error. In that
case the error handling (len <= 0) will be bypassed since "len" is
unsigned, and the loop continues with (p += len) being wrapped.
Change the type of "len" to signed int to fix the error handling.
size_t len;
...
for (...) {
len = audit_log_single_execve_arg(...);
if (len <= 0)
break;
p += len;
}
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
This allows audit to specify rules in which we compare two fields of a
process. Such as is the running process uid != to the running process
euid?
Signed-off-by: Peter Moody <pmoody@google.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
This completes the matrix of interfield comparisons between uid/gid
information for the current task and the uid/gid information for inodes.
aka I can audit based on differences between the euid of the process and
the uid of fs objects.
Signed-off-by: Peter Moody <pmoody@google.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Rather than code the same loop over and over implement a helper function which
uses some pointer magic to make it generic enough to be used numerous places
as we implement more audit interfield comparisons
Signed-off-by: Eric Paris <eparis@redhat.com>
We wish to be able to audit when a uid=500 task accesses a file which is
uid=0. Or vice versa. This patch introduces a new audit filter type
AUDIT_FIELD_COMPARE which takes as an 'enum' which indicates which fields
should be compared. At this point we only define the task->uid vs
inode->uid, but other comparisons can be added.
Signed-off-by: Eric Paris <eparis@redhat.com>
Just a code cleanup really. We don't need to make a function call just for
it to return on error. This also makes the VFS function even easier to follow
and removes a conditional on a hot path.
Signed-off-by: Eric Paris <eparis@redhat.com>
At the moment we allow tasks to set their loginuid if they have
CAP_AUDIT_CONTROL. In reality we want tasks to set the loginuid when they
log in and it be impossible to ever reset. We had to make it mutable even
after it was once set (with the CAP) because on update and admin might have
to restart sshd. Now sshd would get his loginuid and the next user which
logged in using ssh would not be able to set his loginuid.
Systemd has changed how userspace works and allowed us to make the kernel
work the way it should. With systemd users (even admins) are not supposed
to restart services directly. The system will restart the service for
them. Thus since systemd is going to loginuid==-1, sshd would get -1, and
sshd would be allowed to set a new loginuid without special permissions.
If an admin in this system were to manually start an sshd he is inserting
himself into the system chain of trust and thus, logically, it's his
loginuid that should be used! Since we have old systems I make this a
Kconfig option.
Signed-off-by: Eric Paris <eparis@redhat.com>
The function always deals with current. Don't expose an option
pretending one can use it for something. You can't.
Signed-off-by: Eric Paris <eparis@redhat.com>
Much like the ability to filter audit on the uid of an inode collected, we
should be able to filter on the gid of the inode.
Signed-off-by: Eric Paris <eparis@redhat.com>
Allow syscall exit filter matching based on the uid of the owner of an
inode used in a syscall. aka:
auditctl -a always,exit -S open -F obj_uid=0 -F perm=wa
Signed-off-by: Eric Paris <eparis@redhat.com>
Audit entry,always rules are not allowed and are automatically changed in
exit,always rules in userspace. The kernel refuses to load such rules.
Thus a task in the middle of a syscall (and thus in audit_finish_fork())
can only be in one of two states: AUDIT_BUILD_CONTEXT or AUDIT_DISABLED.
Since the current task cannot be in AUDIT_RECORD_CONTEXT we aren't every
going to actually use the code in audit_finish_fork() since it will
return without doing anything. Thus drop the code.
Signed-off-by: Eric Paris <eparis@redhat.com>
A number of audit hooks make function calls before they determine that
auxilary records do not need to be collected. Do those checks as static
inlines since the most common case is going to be that records are not
needed and we can skip the function call overhead.
Signed-off-by: Eric Paris <eparis@redhat.com>
The audit code makes heavy use of likely() and unlikely() macros, but they
don't always make sense. Drop any that seem questionable and let the
computer do it's thing.
Signed-off-by: Eric Paris <eparis@redhat.com>
Audit contexts have 3 states. Disabled, which doesn't collect anything,
build, which collects info but might not emit it, and record, which
collects and emits. There is a 4th state, setup, which isn't used. Get
rid of it.
Signed-off-by: Eric Paris <eparis@redhat.com>
Every arch calls:
if (unlikely(current->audit_context))
audit_syscall_entry()
which requires knowledge about audit (the existance of audit_context) in
the arch code. Just do it all in static inline in audit.h so that arch's
can remain blissfully ignorant.
Signed-off-by: Eric Paris <eparis@redhat.com>
The audit system previously expected arches calling to audit_syscall_exit to
supply as arguments if the syscall was a success and what the return code was.
Audit also provides a helper AUDITSC_RESULT which was supposed to simplify things
by converting from negative retcodes to an audit internal magic value stating
success or failure. This helper was wrong and could indicate that a valid
pointer returned to userspace was a failed syscall. The fix is to fix the
layering foolishness. We now pass audit_syscall_exit a struct pt_reg and it
in turns calls back into arch code to collect the return value and to
determine if the syscall was a success or failure. We also define a generic
is_syscall_success() macro which determines success/failure based on if the
value is < -MAX_ERRNO. This works for arches like x86 which do not use a
separate mechanism to indicate syscall failure.
We make both the is_syscall_success() and regs_return_value() static inlines
instead of macros. The reason is because the audit function must take a void*
for the regs. (uml calls theirs struct uml_pt_regs instead of just struct
pt_regs so audit_syscall_exit can't take a struct pt_regs). Since the audit
function takes a void* we need to use static inlines to cast it back to the
arch correct structure to dereference it.
The other major change is that on some arches, like ia64, MIPS and ppc, we
change regs_return_value() to give us the negative value on syscall failure.
THE only other user of this macro, kretprobe_example.c, won't notice and it
makes the value signed consistently for the audit functions across all archs.
In arch/sh/kernel/ptrace_64.c I see that we were using regs[9] in the old
audit code as the return value. But the ptrace_64.h code defined the macro
regs_return_value() as regs[3]. I have no idea which one is correct, but this
patch now uses the regs_return_value() function, so it now uses regs[3].
For powerpc we previously used regs->result but now use the
regs_return_value() function which uses regs->gprs[3]. regs->gprs[3] is
always positive so the regs_return_value(), much like ia64 makes it negative
before calling the audit code when appropriate.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com> [for x86 portion]
Acked-by: Tony Luck <tony.luck@intel.com> [for ia64]
Acked-by: Richard Weinberger <richard@nod.at> [for uml]
Acked-by: David S. Miller <davem@davemloft.net> [for sparc]
Acked-by: Ralf Baechle <ralf@linux-mips.org> [for mips]
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [for ppc]
The audit system likes to collect information about processes that end
abnormally (SIGSEGV) as this may me useful intrusion detection information.
This patch adds audit support to collect information when seccomp forces a
task to exit because of misbehavior in a similar way.
Signed-off-by: Eric Paris <eparis@redhat.com>
The audit system has the ability to filter on the major and minor number of
the device containing the inode being operated upon. Lets say that
/dev/sda1 has major,minor 8,1 and that we mount /dev/sda1 on /boot. Now lets
say we add a watch with a filter on 8,1. If we proceed to open an inode
inside /boot, such as /vboot/vmlinuz, we will match the major,minor filter.
Lets instead assume that one were to use a tool like debugfs and were to
open /dev/sda1 directly and to modify it's contents. We might hope that
this would also be logged, but it isn't. The rules will check the
major,minor of the device containing /dev/sda1. In other words the rule
would match on the major/minor of the tmpfs mounted at /dev.
I believe these rules should trigger on either device. The man page is
devoid of useful information about the intended semantics. It only seems
logical that if you want to know everything that happened on a major,minor
that would include things that happened to the device itself...
Signed-off-by: Eric Paris <eparis@redhat.com>
userspace audit messages look like so:
type=USER msg=audit(1271170549.415:24710): user pid=14722 uid=0 auid=500 ses=1 subj=unconfined_u:unconfined_r:auditctl_t:s0-s0:c0.c1023 msg=''
That third field just says 'user'. That's useless and doesn't follow the
key=value pair we are trying to enforce. We already know it came from the
user based on the record type. Kill that word. Die.
Signed-off-by: Eric Paris <eparis@redhat.com>
