The 'schedstats=enable' option doesn't work, and also produces the
following warning during boot:
WARNING: CPU: 0 PID: 0 at /home/jpoimboe/git/linux/kernel/jump_label.c:61 static_key_slow_inc+0x8c/0xa0
static_key_slow_inc used before call to jump_label_init
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 4.7.0-rc1+ #25
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014
0000000000000086 3ae3475a4bea95d4 ffffffff81e03da8 ffffffff8143fc83
ffffffff81e03df8 0000000000000000 ffffffff81e03de8 ffffffff810b1ffb
0000003d00000096 ffffffff823514d0 ffff88007ff197c8 0000000000000000
Call Trace:
[<ffffffff8143fc83>] dump_stack+0x85/0xc2
[<ffffffff810b1ffb>] __warn+0xcb/0xf0
[<ffffffff810b207f>] warn_slowpath_fmt+0x5f/0x80
[<ffffffff811e9c0c>] static_key_slow_inc+0x8c/0xa0
[<ffffffff810e07c6>] static_key_enable+0x16/0x40
[<ffffffff8216d633>] setup_schedstats+0x29/0x94
[<ffffffff82148a05>] unknown_bootoption+0x89/0x191
[<ffffffff810d8617>] parse_args+0x297/0x4b0
[<ffffffff82148d61>] start_kernel+0x1d8/0x4a9
[<ffffffff8214897c>] ? set_init_arg+0x55/0x55
[<ffffffff82148120>] ? early_idt_handler_array+0x120/0x120
[<ffffffff821482db>] x86_64_start_reservations+0x2f/0x31
[<ffffffff82148427>] x86_64_start_kernel+0x14a/0x16d
The problem is that it tries to update the 'sched_schedstats' static key
before jump labels have been initialized.
Changing jump_label_init() to be called earlier before
parse_early_param() wouldn't fix it: it would still fail trying to
poke_text() because mm isn't yet initialized.
Instead, just create a temporary '__sched_schedstats' variable which can
be copied to the static key later during sched_init() after jump labels
have been initialized.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: cb2517653f ("sched/debug: Make schedstats a runtime tunable that is disabled by default")
Link: http://lkml.kernel.org/r/453775fe3433bed65731a583e228ccea806d18cd.1465322027.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While this prior commit:
54cf809b95 ("locking,qspinlock: Fix spin_is_locked() and spin_unlock_wait()")
... fixes spin_is_locked() and spin_unlock_wait() for the usage
in ipc/sem and netfilter, it does not in fact work right for the
usage in task_work and futex.
So while the 2 locks crossed problem:
spin_lock(A) spin_lock(B)
if (!spin_is_locked(B)) spin_unlock_wait(A)
foo() foo();
... works with the smp_mb() injected by both spin_is_locked() and
spin_unlock_wait(), this is not sufficient for:
flag = 1;
smp_mb(); spin_lock()
spin_unlock_wait() if (!flag)
// add to lockless list
// iterate lockless list
... because in this scenario, the store from spin_lock() can be delayed
past the load of flag, uncrossing the variables and loosing the
guarantee.
This patch reworks spin_is_locked() and spin_unlock_wait() to work in
both cases by exploiting the observation that while the lock byte
store can be delayed, the contender must have registered itself
visibly in other state contained in the word.
It also allows for architectures to override both functions, as PPC
and ARM64 have an additional issue for which we currently have no
generic solution.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Giovanni Gherdovich <ggherdovich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <waiman.long@hpe.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org # v4.2 and later
Fixes: 54cf809b95 ("locking,qspinlock: Fix spin_is_locked() and spin_unlock_wait()")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In bpf_perf_event_read() and bpf_perf_event_output(), we must use
READ_ONCE() for fetching the struct file pointer, which could get
updated concurrently, so we must prevent the compiler from potential
refetching.
We already do this with tail calls for fetching the related bpf_prog,
but not so on stored perf events. Semantics for both are the same
with regards to updates.
Fixes: a43eec3042 ("bpf: introduce bpf_perf_event_output() helper")
Fixes: 35578d7984 ("bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
To avoid confusion between REQ_OP_FLUSH, which is handled by
request_fn drivers, and upper layers requesting the block layer
perform a flush sequence along with possibly a WRITE, this patch
renames REQ_FLUSH to REQ_PREFLUSH.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This adds a REQ_OP_FLUSH operation that is sent to request_fn
based drivers by the block layer's flush code, instead of
sending requests with the request->cmd_flags REQ_FLUSH bit set.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Have blktrace use the req/bio op accessor to get the REQ_OP.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Separate the op from the rq_flag_bits and have the pm code
set/get the bio using bio_set_op_attrs/bio_op.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw
instead of passing it in. This makes that use the same as
generic_make_request and how we set the other bio fields.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Fixed up fs/ext4/crypto.c
Signed-off-by: Jens Axboe <axboe@fb.com>
When checking the current cred for a capability in a specific user
namespace, it isn't always desirable to have the LSMs audit the check.
This patch adds a noaudit variant of ns_capable() for when those
situations arise.
The common logic between ns_capable() and the new ns_capable_noaudit()
is moved into a single, shared function to keep duplicated code to a
minimum and ease maintainability.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Pull irq fixes from Thomas Gleixner:
- a few simple fixes for fallout from the recent gic-v3 changes
- a workaround for a Cavium thunderX erratum
- a bugfix for the pic32 irqchip to make external interrupts work proper
- a missing return value in the generic IPI management code
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/irq-pic32-evic: Fix bug with external interrupts.
irqchip/gicv3-its: numa: Enable workaround for Cavium thunderx erratum 23144
irqchip/gic-v3: Fix quiescence check in gic_enable_redist
irqchip/gic-v3: Fix copy+paste mistakes in defines
irqchip/gic-v3: Fix ICC_SGI1R_EL1.INTID decoding mask
genirq: Fix missing return value in irq_destroy_ipi()
Merge irqchip updates from Marc Zyngier:
- A number of embarassing buglets (GICv3, PIC32)
- A more substential errata workaround for Cavium's GICv3 ITS
(kept for post-rc1 due to its dependency on NUMA)
Readers that are awoken will expect a nil ->task indicating
that a wakeup has occurred. Because of the way readers are
implemented, there's a small chance that the waiter will never
block in the slowpath (rwsem_down_read_failed), and therefore
requires some form of reference counting to avoid the following
scenario:
rwsem_down_read_failed() rwsem_wake()
get_task_struct();
spin_lock_irq(&wait_lock);
list_add_tail(&waiter.list)
spin_unlock_irq(&wait_lock);
raw_spin_lock_irqsave(&wait_lock)
__rwsem_do_wake()
while (1) {
set_task_state(TASK_UNINTERRUPTIBLE);
waiter->task = NULL
if (!waiter.task) // true
break;
schedule() // never reached
__set_task_state(TASK_RUNNING);
do_exit();
wake_up_process(tsk); // boom
... and therefore race with do_exit() when the caller returns.
There is also a mismatch between the smp_mb() and its documentation,
in that the serialization is done between reading the task and the
nil store. Furthermore, in addition to having the overlapping of
loads and stores to waiter->task guaranteed to be ordered within
that CPU, both wake_up_process() originally and now wake_q_add()
already imply barriers upon successful calls, which serves the
comment.
Now, as an alternative to perhaps inverting the checks in the blocker
side (which has its own penalty in that schedule is unavoidable),
with lockless wakeups this situation is naturally addressed and we
can just use the refcount held by wake_q_add(), instead doing so
explicitly. Of course, we must guarantee that the nil store is done
as the _last_ operation in that the task must already be marked for
deletion to not fall into the race above. Spurious wakeups are also
handled transparently in that the task's reference is only removed
when wake_up_q() is actually called _after_ the nil store.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman.Long@hpe.com
Cc: dave@stgolabs.net
Cc: jason.low2@hp.com
Cc: peter@hurleysoftware.com
Link: http://lkml.kernel.org/r/1463165787-25937-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As wake_qs gain users, we can teach rwsems about them such that
waiters can be awoken without the wait_lock. This is for both
readers and writer, the former being the most ideal candidate
as we can batch the wakeups shortening the critical region that
much more -- ie writer task blocking a bunch of tasks waiting to
service page-faults (mmap_sem readers).
In general applying wake_qs to rwsem (xadd) is not difficult as
the wait_lock is intended to be released soon _anyways_, with
the exception of when a writer slowpath will proactively wakeup
any queued readers if it sees that the lock is owned by a reader,
in which we simply do the wakeups with the lock held (see comment
in __rwsem_down_write_failed_common()).
Similar to other locking primitives, delaying the waiter being
awoken does allow, at least in theory, the lock to be stolen in
the case of writers, however no harm was seen in this (in fact
lock stealing tends to be a _good_ thing in most workloads), and
this is a tiny window anyways.
Some page-fault (pft) and mmap_sem intensive benchmarks show some
pretty constant reduction in systime (by up to ~8 and ~10%) on a
2-socket, 12 core AMD box. In addition, on an 8-core Westmere doing
page allocations (page_test)
aim9:
4.6-rc6 4.6-rc6
rwsemv2
Min page_test 378167.89 ( 0.00%) 382613.33 ( 1.18%)
Min exec_test 499.00 ( 0.00%) 502.67 ( 0.74%)
Min fork_test 3395.47 ( 0.00%) 3537.64 ( 4.19%)
Hmean page_test 395433.06 ( 0.00%) 414693.68 ( 4.87%)
Hmean exec_test 499.67 ( 0.00%) 505.30 ( 1.13%)
Hmean fork_test 3504.22 ( 0.00%) 3594.95 ( 2.59%)
Stddev page_test 17426.57 ( 0.00%) 26649.92 (-52.93%)
Stddev exec_test 0.47 ( 0.00%) 1.41 (-199.05%)
Stddev fork_test 63.74 ( 0.00%) 32.59 ( 48.86%)
Max page_test 429873.33 ( 0.00%) 456960.00 ( 6.30%)
Max exec_test 500.33 ( 0.00%) 507.66 ( 1.47%)
Max fork_test 3653.33 ( 0.00%) 3650.90 ( -0.07%)
4.6-rc6 4.6-rc6
rwsemv2
User 1.12 0.04
System 0.23 0.04
Elapsed 727.27 721.98
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman.Long@hpe.com
Cc: dave@stgolabs.net
Cc: jason.low2@hp.com
Cc: peter@hurleysoftware.com
Link: http://lkml.kernel.org/r/1463165787-25937-2-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The perf_event_aux() function iterates all PMUs and all events in
their respective per-CPU contexts to find the events to deliver
side-band records to.
For example, the brk test case in lkp triggers many mmap() operations,
which, if we're also running perf, results in many perf_event_aux()
invocations.
If we enable uncore PMU support (even when uncore events are not used),
dozens of uncore PMUs will be iterated, which can significantly
decrease brk_test's throughput.
For example, the brk throughput:
without uncore PMUs: 2647573 ops_per_sec
with uncore PMUs: 1768444 ops_per_sec
... a 33% reduction.
To get at the per-CPU events that need side-band records, this patch
puts these events on a per-CPU list, this avoids iterating the PMUs
and any events that do not need side-band records.
Per task events are unchanged to avoid extra overhead on the context
switch paths.
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reported-by: Huang, Ying <ying.huang@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1458757477-3781-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Generally task_struct is only protected by RCU if it was found on a
RCU protected list (say, for_each_process() or find_task_by_vpid()).
As Kirill pointed out rq->curr isn't protected by RCU, the scheduler
drops the (potentially) last reference without RCU gp, this means
that we need to fix the code which uses foreign_rq->curr under
rcu_read_lock().
Add a new helper which can be used to dereference rq->curr or any
other pointer to task_struct assuming that it should be cleared or
updated before the final put_task_struct(). It returns non-NULL
only if this task can't go away before rcu_read_unlock().
( Also add try_get_task_struct() to make it easier to use this API
correctly. )
Suggested-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
[ Updated comments; added try_get_task_struct()]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Link: http://lkml.kernel.org/r/20160518170218.GY3192@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, smp_processor_id() is used to fetch the current CPU in
cpu_idle_loop(). Every time the idle thread runs, it fetches the
current CPU using smp_processor_id().
Since the idle thread is per CPU, the current CPU is constant, so we
can lift the load out of the loop, saving execution cycles/time in the
loop.
x86-64:
Before patch (execution in loop):
148: 0f ae e8 lfence
14b: 65 8b 04 25 00 00 00 00 mov %gs:0x0,%eax
152: 00
153: 89 c0 mov %eax,%eax
155: 49 0f a3 04 24 bt %rax,(%r12)
After patch (execution in loop):
150: 0f ae e8 lfence
153: 4d 0f a3 34 24 bt %r14,(%r12)
ARM64:
Before patch (execution in loop):
168: d5033d9f dsb ld
16c: b9405661 ldr w1,[x19,#84]
170: 1100fc20 add w0,w1,#0x3f
174: 6b1f003f cmp w1,wzr
178: 1a81b000 csel w0,w0,w1,lt
17c: 130c7000 asr w0,w0,#6
180: 937d7c00 sbfiz x0,x0,#3,#32
184: f8606aa0 ldr x0,[x21,x0]
188: 9ac12401 lsr x1,x0,x1
18c: 36000e61 tbz w1,#0,358
After patch (execution in loop):
1a8: d50339df dsb ld
1ac: f8776ac0 ldr x0,[x22,x23]
ab0: ea18001f tst x0,x24
1b4: 54000ea0 b.eq 388
Further observance on ARM64 for 4 seconds shows that cpu_idle_loop is
called 8672 times. Shifting the code will save instructions executed
in loop and eventually time as well.
Signed-off-by: Gaurav Jindal <gaurav.jindal@spreadtrum.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sanjeev Yadav <sanjeev.yadav@spreadtrum.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160512101330.GA488@gauravjindalubtnb.del.spreadtrum.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The design of the cpufreq governor API is not very straightforward,
as struct cpufreq_governor provides only one callback to be invoked
from different code paths for different purposes. The purpose it is
invoked for is determined by its second "event" argument, causing it
to act as a "callback multiplexer" of sorts.
Unfortunately, that leads to extra complexity in governors, some of
which implement the ->governor() callback as a switch statement
that simply checks the event argument and invokes a separate function
to handle that specific event.
That extra complexity can be eliminated by replacing the all-purpose
->governor() callback with a family of callbacks to carry out specific
governor operations: initialization and exit, start and stop and policy
limits updates. That also turns out to reduce the code size too, so
do it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
The cpuidle_devices per-CPU variable is only defined when CPU_IDLE is
enabled. Commit c8cc7d4de7 ("sched/idle: Reorganize the idle loop")
removed the #ifdef CONFIG_CPU_IDLE around cpuidle_idle_call() with the
compiler optimising away __this_cpu_read(cpuidle_devices). However, with
CONFIG_UBSAN && !CONFIG_CPU_IDLE, this optimisation no longer happens
and the kernel fails to link since cpuidle_devices is not defined.
This patch introduces an accessor function for the current CPU cpuidle
device (returning NULL when !CONFIG_CPU_IDLE) and uses it in
cpuidle_idle_call().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: 4.5+ <stable@vger.kernel.org> # 4.5+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull networking fixes from David Miller:
1) Fix negative error code usage in ATM layer, from Stefan Hajnoczi.
2) If CONFIG_SYSCTL is disabled, the default TTL is not initialized
properly. From Ezequiel Garcia.
3) Missing spinlock init in mvneta driver, from Gregory CLEMENT.
4) Missing unlocks in hwmb error paths, also from Gregory CLEMENT.
5) Fix deadlock on team->lock when propagating features, from Ivan
Vecera.
6) Work around buffer offset hw bug in alx chips, from Feng Tang.
7) Fix double listing of SCTP entries in sctp_diag dumps, from Xin
Long.
8) Various statistics bug fixes in mlx4 from Eric Dumazet.
9) Fix some randconfig build errors wrt fou ipv6 from Arnd Bergmann.
10) All of l2tp was namespace aware, but the ipv6 support code was not
doing so. From Shmulik Ladkani.
11) Handle on-stack hrtimers properly in pktgen, from Guenter Roeck.
12) Propagate MAC changes properly through VLAN devices, from Mike
Manning.
13) Fix memory leak in bnx2x_init_one(), from Vitaly Kuznetsov.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (62 commits)
sfc: Track RPS flow IDs per channel instead of per function
usbnet: smsc95xx: fix link detection for disabled autonegotiation
virtio_net: fix virtnet_open and virtnet_probe competing for try_fill_recv
bnx2x: avoid leaking memory on bnx2x_init_one() failures
fou: fix IPv6 Kconfig options
openvswitch: update checksum in {push,pop}_mpls
sctp: sctp_diag should dump sctp socket type
net: fec: update dirty_tx even if no skb
vlan: Propagate MAC address to VLANs
atm: iphase: off by one in rx_pkt()
atm: firestream: add more reserved strings
vxlan: Accept user specified MTU value when create new vxlan link
net: pktgen: Call destroy_hrtimer_on_stack()
timer: Export destroy_hrtimer_on_stack()
net: l2tp: Make l2tp_ip6 namespace aware
Documentation: ip-sysctl.txt: clarify secure_redirects
sfc: use flow dissector helpers for aRFS
ieee802154: fix logic error in ieee802154_llsec_parse_dev_addr
net: nps_enet: Disable interrupts before napi reschedule
net/lapb: tuse %*ph to dump buffers
...
hrtimer_init_on_stack() needs a matching call to
destroy_hrtimer_on_stack(), so both need to be exported.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
In commit 724e4fcc the intention was to pass any errors back from
audit_filter_user_rules() to audit_filter_user(). Add that code.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull vfs fixes from Al Viro:
"Followups to the parallel lookup work:
- update docs
- restore killability of the places that used to take ->i_mutex
killably now that we have down_write_killable() merged
- Additionally, it turns out that I missed a prerequisite for
security_d_instantiate() stuff - ->getxattr() wasn't the only thing
that could be called before dentry is attached to inode; with smack
we needed the same treatment applied to ->setxattr() as well"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
switch ->setxattr() to passing dentry and inode separately
switch xattr_handler->set() to passing dentry and inode separately
restore killability of old mutex_lock_killable(&inode->i_mutex) users
add down_write_killable_nested()
update D/f/directory-locking
Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.
However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.
Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.
This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.
Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.
I was using this definition for testing:
#define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))
which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.
I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.
[ Updated the 9p parts as per Al Viro - Linus ]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull kbuild updates from Michal Marek:
- new option CONFIG_TRIM_UNUSED_KSYMS which does a two-pass build and
unexports symbols which are not used in the current config [Nicolas
Pitre]
- several kbuild rule cleanups [Masahiro Yamada]
- warning option adjustments for gcov etc [Arnd Bergmann]
- a few more small fixes
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (31 commits)
kbuild: move -Wunused-const-variable to W=1 warning level
kbuild: fix if_change and friends to consider argument order
kbuild: fix adjust_autoksyms.sh for modules that need only one symbol
kbuild: fix ksym_dep_filter when multiple EXPORT_SYMBOL() on the same line
gcov: disable -Wmaybe-uninitialized warning
gcov: disable tree-loop-im to reduce stack usage
gcov: disable for COMPILE_TEST
Kbuild: disable 'maybe-uninitialized' warning for CONFIG_PROFILE_ALL_BRANCHES
Kbuild: change CC_OPTIMIZE_FOR_SIZE definition
kbuild: forbid kernel directory to contain spaces and colons
kbuild: adjust ksym_dep_filter for some cmd_* renames
kbuild: Fix dependencies for final vmlinux link
kbuild: better abstract vmlinux sequential prerequisites
kbuild: fix call to adjust_autoksyms.sh when output directory specified
kbuild: Get rid of KBUILD_STR
kbuild: rename cmd_as_s_S to cmd_cpp_s_S
kbuild: rename cmd_cc_i_c to cmd_cpp_i_c
kbuild: drop redundant "PHONY += FORCE"
kbuild: delete unnecessary "@:"
kbuild: mark help target as PHONY
...
When create css failed, before call css_free_rcu_fn, we remove the css
id and exit the percpu_ref, but we will do these again in
css_free_work_fn, so they are redundant. Especially the css id, that
would cause problem if we remove it twice, since it may be assigned to
another css after the first remove.
tj: This was broken by two commits updating the free path without
synchronizing the creation failure path. This can be easily
triggered by trying to create more than 64k memory cgroups.
Signed-off-by: Wenwei Tao <ww.tao0320@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Fixes: 9a1049da9b ("percpu-refcount: require percpu_ref to be exited explicitly")
Fixes: 01e586598b ("cgroup: release css->id after css_free")
Cc: stable@vger.kernel.org # v3.17+
Pull scheduler fixes from Ingo Molnar:
"Two fixes: one for a lost wakeup, the other to fix the compiler
optimizing out preempt operations on ARM64 (and possibly other non-x86
architectures)"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Fix remote wakeups
sched/preempt: Fix preempt_count manipulations
Pull perf updates from Ingo Molnar:
"Mostly tooling and PMU driver fixes, but also a number of late updates
such as the reworking of the call-chain size limiting logic to make
call-graph recording more robust, plus tooling side changes for the
new 'backwards ring-buffer' extension to the perf ring-buffer"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
perf record: Read from backward ring buffer
perf record: Rename variable to make code clear
perf record: Prevent reading invalid data in record__mmap_read
perf evlist: Add API to pause/resume
perf trace: Use the ptr->name beautifier as default for "filename" args
perf trace: Use the fd->name beautifier as default for "fd" args
perf report: Add srcline_from/to branch sort keys
perf evsel: Record fd into perf_mmap
perf evsel: Add overwrite attribute and check write_backward
perf tools: Set buildid dir under symfs when --symfs is provided
perf trace: Only auto set call-graph to "dwarf" when syscalls are being traced
perf annotate: Sort list of recognised instructions
perf annotate: Fix identification of ARM blt and bls instructions
perf tools: Fix usage of max_stack sysctl
perf callchain: Stop validating callchains by the max_stack sysctl
perf trace: Fix exit_group() formatting
perf top: Use machine->kptr_restrict_warned
perf trace: Warn when trying to resolve kernel addresses with kptr_restrict=1
perf machine: Do not bail out if not managing to read ref reloc symbol
perf/x86/intel/p4: Trival indentation fix, remove space
...
Pull more power management updates from Rafael Wysocki:
"These are two stable-candidate fixes (PM core, cpuidle) and a bunch of
cpufreq cleanups.
Specifics:
- Stable-candidate cpuidle fix to make it check the right variable
when deciding whether or not to enable interrupts on the local CPU
so as to avoid enabling iterrupts too early in some cases if the
system has both coupled and per-core idle states (Daniel Lezcano).
- Stable-candidate PM core fix to make it handle failures at the
"late suspend" stage of device suspend consistently for all devices
regardless of whether or not async suspend/resume is enabled for
them (Rafael Wysocki).
- Cleanups in the cpufreq core, the schedutil governor and the
intel_pstate driver (Rafael Wysocki, Pankaj Gupta, Viresh Kumar)"
* tag 'pm-4.7-rc1-more' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / sleep: Handle failures in device_suspend_late() consistently
cpufreq: schedutil: Improve prints messages with pr_fmt
cpuidle: Fix cpuidle_state_is_coupled() argument in cpuidle_enter()
cpufreq: simplified goto out in cpufreq_register_driver()
cpufreq: governor: CPUFREQ_GOV_STOP never fails
cpufreq: governor: CPUFREQ_GOV_POLICY_EXIT never fails
intel_pstate: Simplify conditional in intel_pstate_set_policy()
