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2016-09-24Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "Three fixes for irq core and irq chip drivers: - Do not set the irq type if type is NONE. Fixes a boot regression on various SoCs - Use the proper cpu for setting up the GIC target list. Discovered by the cpumask debugging code. - A rather large fix for the MIPS-GIC so per cpu local interrupts work again. This was discovered late because the code falls back to slower timers which use normal device interrupts" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/mips-gic: Fix local interrupts irqchip/gicv3: Silence noisy DEBUG_PER_CPU_MAPS warning genirq: Skip chained interrupt trigger setup if type is IRQ_TYPE_NONE
2016-09-23cgroup: fix invalid controller enable rejections with cgroup namespaceTejun Heo
On the v2 hierarchy, "cgroup.subtree_control" rejects controller enables if the cgroup has processes in it. The enforcement of this logic assumes that the cgroup wouldn't have any css_sets associated with it if there are no tasks in the cgroup, which is no longer true since a79a908fd2b0 ("cgroup: introduce cgroup namespaces"). When a cgroup namespace is created, it pins the css_set of the creating task to use it as the root css_set of the namespace. This extra reference stays as long as the namespace is around and makes "cgroup.subtree_control" think that the namespace root cgroup is not empty even when it is and thus reject controller enables. Fix it by making cgroup_subtree_control() walk and test emptiness of each css_set instead of testing whether the list_head is empty. While at it, update the comment of cgroup_task_count() to indicate that the returned value may be higher than the number of tasks, which has always been true due to temporary references and doesn't break anything. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Evgeny Vereshchagin <evvers@ya.ru> Cc: Serge E. Hallyn <serge.hallyn@ubuntu.com> Cc: Aditya Kali <adityakali@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: stable@vger.kernel.org # v4.6+ Fixes: a79a908fd2b0 ("cgroup: introduce cgroup namespaces") Link: https://github.com/systemd/systemd/pull/3589#issuecomment-249089541
2016-09-23tracing: Call traceoff trigger after event is recordedMasami Hiramatsu
Call traceoff trigger after the event is recorded. Since current traceoff trigger is called before recording the event, we can not know what event stopped tracing. Typical usecase of traceoff/traceon trigger is tracing function calls and trace events between a pair of events. For example, trace function calls between syscall entry/exit. In that case, it is useful if we can see the return code of the target syscall. Link: http://lkml.kernel.org/r/147335074530.12462.4526186083406015005.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-09-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2016-09-23Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22Merge branch 'nsfs-ioctls' into HEADEric W. Biederman
From: Andrey Vagin <avagin@openvz.org> Each namespace has an owning user namespace and now there is not way to discover these relationships. Pid and user namepaces are hierarchical. There is no way to discover parent-child relationships too. Why we may want to know relationships between namespaces? One use would be visualization, in order to understand the running system. Another would be to answer the question: what capability does process X have to perform operations on a resource governed by namespace Y? One more use-case (which usually called abnormal) is checkpoint/restart. In CRIU we are going to dump and restore nested namespaces. There [1] was a discussion about which interface to choose to determing relationships between namespaces. Eric suggested to add two ioctl-s [2]: > Grumble, Grumble. I think this may actually a case for creating ioctls > for these two cases. Now that random nsfs file descriptors are bind > mountable the original reason for using proc files is not as pressing. > > One ioctl for the user namespace that owns a file descriptor. > One ioctl for the parent namespace of a namespace file descriptor. Here is an implementaions of these ioctl-s. $ man man7/namespaces.7 ... Since Linux 4.X, the following ioctl(2) calls are supported for namespace file descriptors. The correct syntax is: fd = ioctl(ns_fd, ioctl_type); where ioctl_type is one of the following: NS_GET_USERNS Returns a file descriptor that refers to an owning user names‐ pace. NS_GET_PARENT Returns a file descriptor that refers to a parent namespace. This ioctl(2) can be used for pid and user namespaces. For user namespaces, NS_GET_PARENT and NS_GET_USERNS have the same meaning. In addition to generic ioctl(2) errors, the following specific ones can occur: EINVAL NS_GET_PARENT was called for a nonhierarchical namespace. EPERM The requested namespace is outside of the current namespace scope. [1] https://lkml.org/lkml/2016/7/6/158 [2] https://lkml.org/lkml/2016/7/9/101 Changes for v2: * don't return ENOENT for init_user_ns and init_pid_ns. There is nothing outside of the init namespace, so we can return EPERM in this case too. > The fewer special cases the easier the code is to get > correct, and the easier it is to read. // Eric Changes for v3: * rename ns->get_owner() to ns->owner(). get_* usually means that it grabs a reference. Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> Cc: "W. Trevor King" <wking@tremily.us> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Serge Hallyn <serge.hallyn@canonical.com>
2016-09-22nsfs: add ioctl to get a parent namespaceAndrey Vagin
Pid and user namepaces are hierarchical. There is no way to discover parent-child relationships. In a future we will use this interface to dump and restore nested namespaces. Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-09-22kernel: add a helper to get an owning user namespace for a namespaceAndrey Vagin
Return -EPERM if an owning user namespace is outside of a process current user namespace. v2: In a first version ns_get_owner returned ENOENT for init_user_ns. This special cases was removed from this version. There is nothing outside of init_user_ns, so we can return EPERM. v3: rename ns->get_owner() to ns->owner(). get_* usually means that it grabs a reference. Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-09-23kvmconfig: add virtio-gpu to config fragmentRob Herring
virtio-gpu is used for VMs, so add it to the kvm config. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: kvmarm@lists.cs.columbia.edu Cc: kvm@vger.kernel.org [expanded "frag" to "fragment" in summary] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-09-23config: move x86 kvm_guest.config to a common locationRob Herring
kvm_guest.config is useful for KVM guests on other arches, and nothing in it appears to be x86 specific, so just move the whole file. Kbuild will find it in either location. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: kvmarm@lists.cs.columbia.edu Cc: kvm@vger.kernel.org Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-09-22userns: When the per user per user namespace limit is reached return ENOSPCEric W. Biederman
The current error codes returned when a the per user per user namespace limit are hit (EINVAL, EUSERS, and ENFILE) are wrong. I asked for advice on linux-api and it we made clear that those were the wrong error code, but a correct effor code was not suggested. The best general error code I have found for hitting a resource limit is ENOSPC. It is not perfect but as it is unambiguous it will serve until someone comes up with a better error code. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-09-22locking/lglock: Remove lglock implementationPeter Zijlstra
It is now unused, remove it before someone else thinks its a good idea to use this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22stop_machine: Remove stop_cpus_lock and lg_double_lock/unlock()Oleg Nesterov
stop_two_cpus() and stop_cpus() use stop_cpus_lock to avoid the deadlock, we need to ensure that the stopper functions can't be queued "backwards" from one another. This doesn't look nice; if we use lglock then we do not really need stopper->lock, cpu_stop_queue_work() could use lg_local_lock() under local_irq_save(). OTOH it would be even better to avoid lglock in stop_machine.c and remove lg_double_lock(). This patch adds "bool stop_cpus_in_progress" set/cleared by queue_stop_cpus_work(), and changes cpu_stop_queue_two_works() to busy wait until it is cleared. queue_stop_cpus_work() sets stop_cpus_in_progress = T lockless, but after it queues a work on CPU1 it must be visible to stop_two_cpus(CPU1, CPU2) which checks it under the same lock. And since stop_two_cpus() holds the 2nd lock too, queue_stop_cpus_work() can not clear stop_cpus_in_progress if it is also going to queue a work on CPU2, it needs to take that 2nd lock to do this. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20151121181148.GA433@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22locking/pv-qspinlock: Use cmpxchg_release() in __pv_queued_spin_unlock()Pan Xinhui
cmpxchg_release() is more lighweight than cmpxchg() on some archs(e.g. PPC), moreover, in __pv_queued_spin_unlock() we only needs a RELEASE in the fast path(pairing with *_try_lock() or *_lock()). And the slow path has smp_store_release too. So it's safe to use cmpxchg_release here. Suggested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: benh@kernel.crashing.org Cc: linuxppc-dev@lists.ozlabs.org Cc: mpe@ellerman.id.au Cc: paulmck@linux.vnet.ibm.com Cc: paulus@samba.org Cc: virtualization@lists.linux-foundation.org Cc: waiman.long@hpe.com Link: http://lkml.kernel.org/r/1474277037-15200-2-git-send-email-xinhui.pan@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22Merge branch 'locking/urgent' into locking/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22sched/debug: Hide printk() by defaultPeter Zijlstra
Dietmar accidentally added an unconditional sched domain printk. Hide it behind the normal sched_debug flag. Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Fixes: cd92bfd3b8cb ("sched/core: Store maximum per-CPU capacity in root domain") [ Fixed !SCHED_DEBUG build failure. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22sched/fair: Fix SCHED_HRTICK bug leading to late preemption of tasksSrivatsa Vaddagiri
SCHED_HRTICK feature is useful to preempt SCHED_FAIR tasks on-the-dot (just when they would have exceeded their ideal_runtime). It makes use of a per-CPU hrtimer resource and hence arming that hrtimer should be based on total SCHED_FAIR tasks a CPU has across its various cfs_rqs, rather than being based on number of tasks in a particular cfs_rq (as implemented currently). As a result, with current code, its possible for a running task (which is the sole task in its cfs_rq) to be preempted much after its ideal_runtime has elapsed, resulting in increased latency for tasks in other cfs_rq on same CPU. Fix this by arming sched hrtimer based on total number of SCHED_FAIR tasks a CPU has across its various cfs_rqs. Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org> Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1474075731-11550-1-git-send-email-joonwoop@codeaurora.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22perf/core: Limit matching exclusive events to one PMUAlexander Shishkin
An "exclusive" PMU is the one that can only have one event scheduled in at any given time. There may be more than one of such PMUs in a system, though, like Intel PT and BTS. It should be allowed to have one event for either of those inside the same context (there may be other constraints that may prevent this, but those would be hardware-specific). However, the exclusivity code is written so that only one event from any of the "exclusive" PMUs is allowed in a context. Fix this by making the exclusive event filter explicitly match two events' PMUs. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> 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> Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160920154811.3255-3-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22sched/core: Avoid _cond_resched() for PREEMPT=yPeter Zijlstra
On fully preemptible kernels _cond_resched() is pointless, so avoid emitting any code for it. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22sched/core: Optimize __schedule()Peter Zijlstra
Oleg noted that by making do_exit() use __schedule() for the TASK_DEAD context switch, we can avoid the TASK_DEAD special case currently in __schedule() because that avoids the extra preempt_disable() from schedule(). In order to facilitate this, create a do_task_dead() helper which we place in the scheduler code, such that it can access __schedule(). Also add some __noreturn annotations to the functions, there's no coming back from do_exit(). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Cheng Chao <cs.os.kernel@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: chris@chris-wilson.co.uk Cc: tj@kernel.org Link: http://lkml.kernel.org/r/20160913163729.GB5012@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22stop_machine: Avoid a sleep and wakeup in stop_one_cpu()Cheng Chao
In case @cpu == smp_proccessor_id(), we can avoid a sleep+wakeup cycle by doing a preemption. Callers such as sched_exec() can benefit from this change. Signed-off-by: Cheng Chao <cs.os.kernel@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: chris@chris-wilson.co.uk Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1473818510-6779-1-git-send-email-cs.os.kernel@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22sched/core: Remove unnecessary initialization in sched_init()Cheng Chao
init_idle() is called immediately after: current->sched_class = &fair_sched_class; init_idle() sets: current->sched_class = &idle_sched_class; First assignment is superfluous. Signed-off-by: Cheng Chao <cs.os.kernel@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1473819536-7398-1-git-send-email-cs.os.kernel@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22smp: Allocate smp_call_on_cpu() workqueue on stack tooPeter Zijlstra
The SMP IPI struct descriptor is allocated on the stack except for the workqueue and lockdep complains: INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 0 PID: 110 Comm: kworker/0:1 Not tainted 4.8.0-rc5+ #14 Hardware name: Dell Inc. Precision T3600/0PTTT9, BIOS A13 05/11/2014 Workqueue: events smp_call_on_cpu_callback ... Call Trace: dump_stack register_lock_class ? __lock_acquire __lock_acquire ? __lock_acquire lock_acquire ? process_one_work process_one_work ? process_one_work worker_thread ? process_one_work ? process_one_work kthread ? kthread_create_on_node ret_from_fork So allocate it on the stack too. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> [ Test and write commit message. ] Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160911084323.jhtnpb4b37t5tlno@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-22sched/core: Do not use smp_processor_id() with preempt enabled in ↵Con Kolivas
smpboot_thread_fn() We should not be using smp_processor_id() with preempt enabled. Bug identified and fix provided by Alfred Chen. Reported-by: Alfred Chen <cchalpha@gmail.com> Signed-off-by: Con Kolivas <kernel@kolivas.org> Cc: Alfred Chen <cchalpha@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/2042051.3vvUWIM0vs@hex Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-21bpf: recognize 64bit immediate loads as constsJakub Kicinski
When running as parser interpret BPF_LD | BPF_IMM | BPF_DW instructions as loading CONST_IMM with the value stored in imm. The verifier will continue not recognizing those due to concerns about search space/program complexity increase. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-21bpf: enable non-core use of the verfierJakub Kicinski
Advanced JIT compilers and translators may want to use eBPF verifier as a base for parsers or to perform custom checks and validations. Add ability for external users to invoke the verifier and provide callbacks to be invoked for every intruction checked. For now only add most basic callback for per-instruction pre-interpretation checks is added. More advanced users may also like to have per-instruction post callback and state comparison callback. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-21bpf: expose internal verfier structuresJakub Kicinski
Move verifier's internal structures to a header file and prefix their names with bpf_ to avoid potential namespace conflicts. Those structures will soon be used by external analyzers. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-21bpf: don't (ab)use instructions to store stateJakub Kicinski
Storing state in reserved fields of instructions makes it impossible to run verifier on programs already marked as read-only. Allocate and use an array of per-instruction state instead. While touching the error path rename and move existing jump target. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-20bpf: direct packet write and access for helpers for clsact progsDaniel Borkmann
This work implements direct packet access for helpers and direct packet write in a similar fashion as already available for XDP types via commits 4acf6c0b84c9 ("bpf: enable direct packet data write for xdp progs") and 6841de8b0d03 ("bpf: allow helpers access the packet directly"), and as a complementary feature to the already available direct packet read for tc (cls/act) programs. For enabling this, we need to introduce two helpers, bpf_skb_pull_data() and bpf_csum_update(). The first is generally needed for both, read and write, because they would otherwise only be limited to the current linear skb head. Usually, when the data_end test fails, programs just bail out, or, in the direct read case, use bpf_skb_load_bytes() as an alternative to overcome this limitation. If such data sits in non-linear parts, we can just pull them in once with the new helper, retest and eventually access them. At the same time, this also makes sure the skb is uncloned, which is, of course, a necessary condition for direct write. As this needs to be an invariant for the write part only, the verifier detects writes and adds a prologue that is calling bpf_skb_pull_data() to effectively unclone the skb from the very beginning in case it is indeed cloned. The heuristic makes use of a similar trick that was done in 233577a22089 ("net: filter: constify detection of pkt_type_offset"). This comes at zero cost for other programs that do not use the direct write feature. Should a program use this feature only sparsely and has read access for the most parts with, for example, drop return codes, then such write action can be delegated to a tail called program for mitigating this cost of potential uncloning to a late point in time where it would have been paid similarly with the bpf_skb_store_bytes() as well. Advantage of direct write is that the writes are inlined whereas the helper cannot make any length assumptions and thus needs to generate a call to memcpy() also for small sizes, as well as cost of helper call itself with sanity checks are avoided. Plus, when direct read is already used, we don't need to cache or perform rechecks on the data boundaries (due to verifier invalidating previous checks for helpers that change skb->data), so more complex programs using rewrites can benefit from switching to direct read plus write. For direct packet access to helpers, we save the otherwise needed copy into a temp struct sitting on stack memory when use-case allows. Both facilities are enabled via may_access_direct_pkt_data() in verifier. For now, we limit this to map helpers and csum_diff, and can successively enable other helpers where we find it makes sense. Helpers that definitely cannot be allowed for this are those part of bpf_helper_changes_skb_data() since they can change underlying data, and those that write into memory as this could happen for packet typed args when still cloned. bpf_csum_update() helper accommodates for the fact that we need to fixup checksum_complete when using direct write instead of bpf_skb_store_bytes(), meaning the programs can use available helpers like bpf_csum_diff(), and implement csum_add(), csum_sub(), csum_block_add(), csum_block_sub() equivalents in eBPF together with the new helper. A usage example will be provided for iproute2's examples/bpf/ directory. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-20bpf, verifier: enforce larger zero range for pkt on overloading stack buffsDaniel Borkmann
Current contract for the following two helper argument types is: * ARG_CONST_STACK_SIZE: passed argument pair must be (ptr, >0). * ARG_CONST_STACK_SIZE_OR_ZERO: passed argument pair can be either (NULL, 0) or (ptr, >0). With 6841de8b0d03 ("bpf: allow helpers access the packet directly"), we can pass also raw packet data to helpers, so depending on the argument type being PTR_TO_PACKET, we now either assert memory via check_packet_access() or check_stack_boundary(). As a result, the tests in check_packet_access() currently allow more than intended with regards to reg->imm. Back in 969bf05eb3ce ("bpf: direct packet access"), check_packet_access() was fine to ignore size argument since in check_mem_access() size was bpf_size_to_bytes() derived and prior to the call to check_packet_access() guaranteed to be larger than zero. However, for the above two argument types, it currently means, we can have a <= 0 size and thus breaking current guarantees for helpers. Enforce a check for size <= 0 and bail out if so. check_stack_boundary() doesn't have such an issue since it already tests for access_size <= 0 and bails out, resp. access_size == 0 in case of NULL pointer passed when allowed. Fixes: 6841de8b0d03 ("bpf: allow helpers access the packet directly") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-20Merge branch 'irq/urgent' into irq/coreThomas Gleixner
Merge urgent fixes so pending patches for 4.9 can be applied.
2016-09-20Merge branch 'linus' into x86/asm, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-19cgroup: duplicate cgroup reference when cloning socketsJohannes Weiner
When a socket is cloned, the associated sock_cgroup_data is duplicated but not its reference on the cgroup. As a result, the cgroup reference count will underflow when both sockets are destroyed later on. Fixes: bd1060a1d671 ("sock, cgroup: add sock->sk_cgroup") Link: http://lkml.kernel.org/r/20160914194846.11153-2-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: <stable@vger.kernel.org> [4.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-19padata: Convert to hotplug state machineSebastian Andrzej Siewior
Install the callbacks via the state machine. CPU-hotplug multinstance support is used with the nocalls() version. Maybe parts of padata_alloc() could be moved into the online callback so that we could invoke ->startup callback for instance and drop get_online_cpus(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-crypto@vger.kernel.org Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160906170457.32393-14-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-19genirq: Skip chained interrupt trigger setup if type is IRQ_TYPE_NONEMarc Zyngier
There is no point in trying to configure the trigger of a chained interrupt if no trigger information has been configured. At best this is ignored, and at the worse this confuses the underlying irqchip (which is likely not to handle such a thing), and unnecessarily alarms the user. Only apply the configuration if type is not IRQ_TYPE_NONE. Fixes: 1e12c4a9393b ("genirq: Correctly configure the trigger on chained interrupts") Reported-and-tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Link: https://lkml.kernel.org/r/CAMuHMdVW1eTn20=EtYcJ8hkVwohaSuH_yQXrY2MGBEvZ8fpFOg@mail.gmail.com Link: http://lkml.kernel.org/r/1474274967-15984-1-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-16cpuset: fix non static symbol warningWei Yongjun
Fixes the following sparse warning: kernel/cpuset.c:2088:6: warning: symbol 'cpuset_fork' was not declared. Should it be static? Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-09-16fork: Optimize task creation by caching two thread stacks per CPU if ↵Andy Lutomirski
CONFIG_VMAP_STACK=y vmalloc() is a bit slow, and pounding vmalloc()/vfree() will eventually force a global TLB flush. To reduce pressure on them, if CONFIG_VMAP_STACK=y, cache two thread stacks per CPU. This will let us quickly allocate a hopefully cache-hot, TLB-hot stack under heavy forking workloads (shell script style). On my silly pthread_create() benchmark, it saves about 2 µs per pthread_create()+join() with CONFIG_VMAP_STACK=y. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jann Horn <jann@thejh.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/94811d8e3994b2e962f88866290017d498eb069c.1474003868.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-16sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASKAndy Lutomirski
We currently keep every task's stack around until the task_struct itself is freed. This means that we keep the stack allocation alive for longer than necessary and that, under load, we free stacks in big batches whenever RCU drops the last task reference. Neither of these is good for reuse of cache-hot memory, and freeing in batches prevents us from usefully caching small numbers of vmalloced stacks. On architectures that have thread_info on the stack, we can't easily change this, but on architectures that set THREAD_INFO_IN_TASK, we can free it as soon as the task is dead. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jann Horn <jann@thejh.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/08ca06cde00ebed0046c5d26cbbf3fbb7ef5b812.1474003868.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-16kthread: Pin the stack via try_get_task_stack()/put_task_stack() in ↵Oleg Nesterov
to_live_kthread() function get_task_struct(tsk) no longer pins tsk->stack so all users of to_live_kthread() should do try_get_task_stack/put_task_stack to protect "struct kthread" which lives on kthread's stack. TODO: Kill to_live_kthread(), perhaps we can even kill "struct kthread" too, and rework kthread_stop(), it can use task_work_add() to sync with the exiting kernel thread. Message-Id: <20160629180357.GA7178@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jann Horn <jann@thejh.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/cb9b16bbc19d4aea4507ab0552e4644c1211d130.1474003868.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-16Merge branch 'for-mingo' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU changes from Paul E. McKenney: - Expedited grace-period changes, most notably avoiding having user threads drive expedited grace periods, using a workqueue instead. - Miscellaneous fixes, including a performance fix for lists that was sent with the lists modifications (second URL below). - CPU hotplug updates, most notably providing exact CPU-online tracking for RCU. This will in turn allow removal of the checks supporting RCU's prior heuristic that was based on the assumption that CPUs would take no longer than one jiffy to come online. - Torture-test updates. - Documentation updates. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-15Merge branch 'irq/for-block' into irq/coreThomas Gleixner
Add the new irq spreading infrastructure.
2016-09-15sched/core: Allow putting thread_info into task_structAndy Lutomirski
If an arch opts in by setting CONFIG_THREAD_INFO_IN_TASK_STRUCT, then thread_info is defined as a single 'u32 flags' and is the first entry of task_struct. thread_info::task is removed (it serves no purpose if thread_info is embedded in task_struct), and thread_info::cpu gets its own slot in task_struct. This is heavily based on a patch written by Linus. Originally-from: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jann Horn <jann@thejh.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a0898196f0476195ca02713691a5037a14f2aac5.1473801993.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-15Merge branch 'linus' into x86/asm, to pick up recent fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-14genirq/affinity: Remove old irq spread infrastructureThomas Gleixner
No more users. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Christoph Hellwig <hch@lst.de> Cc: axboe@fb.com Cc: keith.busch@intel.com Cc: agordeev@redhat.com Cc: linux-block@vger.kernel.org Link: http://lkml.kernel.org/r/1473862739-15032-5-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-14genirq/msi: Switch to new irq spreading infrastructureThomas Gleixner
Switch MSI over to the new spreading code. If a pci device contains a valid pointer to a cpumask, then this mask is used for spreading otherwise the online cpu mask is used. This allows a driver to restrict the spread to a subset of CPUs, e.g. cpus on a particular node. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Christoph Hellwig <hch@lst.de> Cc: axboe@fb.com Cc: keith.busch@intel.com Cc: agordeev@redhat.com Cc: linux-block@vger.kernel.org Link: http://lkml.kernel.org/r/1473862739-15032-4-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-14genirq/affinity: Provide smarter irq spreading infrastructureThomas Gleixner
The current irq spreading infrastructure is just looking at a cpumask and tries to spread the interrupts over the mask. Thats suboptimal as it does not take numa nodes into account. Change the logic so the interrupts are spread across numa nodes and inside the nodes. If there are more cpus than vectors per node, then we set the affinity to several cpus. If HT siblings are available we take that into account and try to set all siblings to a single vector. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Christoph Hellwig <hch@lst.de> Cc: axboe@fb.com Cc: keith.busch@intel.com Cc: agordeev@redhat.com Cc: linux-block@vger.kernel.org Link: http://lkml.kernel.org/r/1473862739-15032-3-git-send-email-hch@lst.de
2016-09-14genirq/msi: Add cpumask allocation to alloc_msi_entryThomas Gleixner
For irq spreading want to store affinity masks in the msi_entry. Add the infrastructure for it. We allocate an array of cpumasks with an array size of the number of used vectors in the entry, so we can hand in the information per linux interrupt later. As we hand in the number of used vectors, we assign them right away. Convert all the call sites. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: axboe@fb.com Cc: keith.busch@intel.com Cc: agordeev@redhat.com Cc: linux-block@vger.kernel.org Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/1473862739-15032-2-git-send-email-hch@lst.de
2016-09-14Merge branches 'doc.2016.08.22c', 'exp.2016.08.22c', 'fixes.2016.09.14a', ↵Paul E. McKenney
'hotplug.2016.08.22c' and 'torture.2016.08.22c' into HEAD doc.2016.08.22c: Documentation updates exp.2016.08.22c: Expedited grace-period updates fixes.2016.09.14a: Miscellaneous fixes hotplug.2016.08.22c: CPU-hotplug changes torture.2016.08.22c: Torture-test changes
2016-09-14x86/signal: Add SA_{X32,IA32}_ABI sa_flagsDmitry Safonov
Introduce new flags that defines which ABI to use on creating sigframe. Those flags kernel will set according to sigaction syscall ABI, which set handler for the signal being delivered. So that will drop the dependency on TIF_IA32/TIF_X32 flags on signal deliver. Those flags will be used only under CONFIG_COMPAT. Similar way ARM uses sa_flags to differ in which mode deliver signal for 26-bit applications (look at SA_THIRYTWO). Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: 0x7f454c46@gmail.com Cc: oleg@redhat.com Cc: linux-mm@kvack.org Cc: gorcunov@openvz.org Cc: xemul@virtuozzo.com Link: http://lkml.kernel.org/r/20160905133308.28234-7-dsafonov@virtuozzo.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>