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* vhost: introduce vhost_vq_avail_empty()Jason Wang2016-03-10
| | | | | | | | | | This patch introduces a helper which will return true if we're sure that the available ring is empty for a specific vq. When we're not sure, e.g vq access failure, return false instead. This could be used for busy polling code to exit the busy loop. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: introduce vhost_has_work()Jason Wang2016-03-10
| | | | | | | | | This path introduces a helper which can give a hint for whether or not there's a work queued in the work list. This could be used for busy polling code to exit the busy loop. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio_balloon: Allow to resize and update the balloon stats in parallelPetr Mladek2016-03-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The virtio balloon statistics are not updated when the balloon is being resized. But it seems that both tasks could be done in parallel. stats_handle_request() updates the statistics in the balloon structure and then communicates with the host. update_balloon_stats() calls all_vm_events() that just reads some per-CPU variables. The values might change during and after the call but it is expected and happens even without this patch. update_balloon_stats() also calls si_meminfo(). It is a bit more complex function. It too just reads some variables and looks lock-less safe. In each case, it seems to be called lock-less on several similar locations, e.g. from post_status() in dm_thread_func(), or from vmballoon_send_get_target(). The communication with the host is done via a separate virtqueue, see vb->stats_vq vs. vb->inflate_vq and vb->deflate_vq. Therefore it could be used in parallel with fill_balloon() and leak_balloon(). This patch splits the existing work into two pieces. One is for updating the balloon stats. The other is for resizing of the balloon. It seems that they can be proceed in parallel without any extra locking. Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio_balloon: Use a workqueue instead of "vballoon" kthreadPetr Mladek2016-03-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch moves the deferred work from the "vballoon" kthread into a system freezable workqueue. We do not need to maintain and run a dedicated kthread. Also the event driven workqueues API makes the logic much easier. Especially, we do not longer need an own wait queue, wait function, and freeze point. The conversion is pretty straightforward. One cycle of the main loop is put into a work. The work is queued instead of waking the kthread. fill_balloon() and leak_balloon() have a limit for the amount of modified pages. The work re-queues itself when necessary. For this, we make fill_balloon() to return the number of really modified pages. Note that leak_balloon() already did this. virtballoon_restore() queues the work only when really needed. The only complication is that we need to prevent queuing the work when the balloon is being removed. It was easier before because the kthread simply removed itself from the wait queue. We need an extra boolean and spin lock now. My initial idea was to use a dedicated workqueue. Michael S. Tsirkin suggested using a system one. Tejun Heo confirmed that the system workqueue has a pretty high concurrency level (256) by default. Therefore we need not be afraid of too long blocking. Signed-off-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio/s390: size of SET_IND payloadCornelia Huck2016-03-02
| | | | | | | | | | | | | | | | SET_IND takes as a payload the _address_ of the indicators, meaning that we have one of the rare cases where kmalloc(sizeof(&...)) is actually correct. Let's clarify that with a comment. The count for the ccw, however, was only correct because the indicators are 64 bit. Let's use the correct value. Reported-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio/s390: use dev_to_virtioGeliang Tang2016-03-02
| | | | | | | | | | Use dev_to_virtio() instead of open-coding it. Signed-off-by: Geliang Tang <geliangtang@163.com> Message-Id: <912bf59bd3a48f2d4d4994681e898dc084fe29d3.1451484163.git.geliangtang@163.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: rename vhost_init_used()Greg Kurz2016-03-02
| | | | | | | | | | | | | | | | | | Looking at how callers use this, maybe we should just rename init_used to vhost_vq_init_access. The _used suffix was a hint that we access the vq used ring. But maybe what callers care about is that it must be called after access_ok. Also, this function manipulates the vq->is_le field which isn't related to the vq used ring. This patch simply renames vhost_init_used() to vhost_vq_init_access() as suggested by Michael. No behaviour change. Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: rename cross-endian helpersGreg Kurz2016-03-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The default use case for vhost is when the host and the vring have the same endianness (default native endianness). But there are cases where they differ and vhost should byteswap when accessing the vring. The first case is when the host is big endian and the vring belongs to a virtio 1.0 device, which is always little endian. This is covered by the vq->is_le field. This field is initialized when userspace calls the VHOST_SET_FEATURES ioctl. It is reset when the device stops. We already have a vhost_init_is_le() helper, but the reset operation is opencoded as follows: vq->is_le = virtio_legacy_is_little_endian(); It isn't clear that we are resetting vq->is_le here. This patch moves the code to a helper with a more explicit name. The other case where we may have to byteswap is when the architecture can switch endianness at runtime (bi-endian). If endianness differs in the host and in the guest, then legacy devices need to be used in cross-endian mode. This mode is available with CONFIG_VHOST_CROSS_ENDIAN_LEGACY=y, which introduces a vq->user_be field. Userspace may enable cross-endian mode by calling the SET_VRING_ENDIAN ioctl before the device is started. The cross-endian mode is disabled when the device is stopped. The current names of the helpers that manipulate vq->user_be are unclear. This patch renames those helpers to clearly show that this is cross-endian stuff and with explicit enable/disable semantics. No behaviour change. Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio_blk: VIRTIO_BLK_F_WCE->VIRTIO_BLK_F_FLUSHMichael S. Tsirkin2016-03-02
| | | | | | | | | Latest virtio spec says the feature bit name is VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_WCE is the legacy name. virtio blk header says exactly the reverse - fix that and update driver code to match. Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vring: Use the DMA API on XenAndy Lutomirski2016-03-02
| | | | | | | Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Wei Liu <wei.liu2@citrix.com>
* virtio_pci: Use the DMA API if enabledAndy Lutomirski2016-03-02
| | | | | | | | | | | | | This switches to vring_create_virtqueue, simplifying the driver and adding DMA API support. This fixes virtio-pci on platforms and busses that have IOMMUs. This will break the experimental QEMU Q35 IOMMU support until QEMU is fixed. In exchange, it fixes physical virtio hardware as well as virtio-pci running under Xen. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio_mmio: Use the DMA API if enabledAndy Lutomirski2016-03-02
| | | | | | | | This switches to vring_create_virtqueue, simplifying the driver and adding DMA API support. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio: Add improved queue allocation APIAndy Lutomirski2016-03-02
| | | | | | | | | | | | | | | | This leaves vring_new_virtqueue alone for compatbility, but it adds two new improved APIs: vring_create_virtqueue: Creates a virtqueue backed by automatically allocated coherent memory. (Some day it this could be extended to support non-coherent memory, too, if there ends up being a platform on which it's worthwhile.) __vring_new_virtqueue: Creates a virtqueue with a manually-specified layout. This should allow mic_virtio to work much more cleanly. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio_ring: Support DMA APIsAndy Lutomirski2016-03-02
| | | | | | | | | | | | | | | | | virtio_ring currently sends the device (usually a hypervisor) physical addresses of its I/O buffers. This is okay when DMA addresses and physical addresses are the same thing, but this isn't always the case. For example, this never works on Xen guests, and it is likely to fail if a physical "virtio" device ever ends up behind an IOMMU or swiotlb. The immediate use case for me is to enable virtio on Xen guests. For that to work, we need vring to support DMA address translation as well as a corresponding change to virtio_pci or to another driver. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vring: Introduce vring_use_dma_api()Andy Lutomirski2016-03-02
| | | | | | | | | | | This is a kludge, but no one has come up with a a better idea yet. We'll introduce DMA API support guarded by vring_use_dma_api(). Eventually we may be able to return true on more and more systems, and hopefully we can get rid of vring_use_dma_api() entirely some day. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* s390/dma: Allow per device dma opsChristian Borntraeger2016-03-02
| | | | | | | | | | | | | | | | | As virtio-ccw will have dma ops, we can no longer default to the zPCI ones. Make use of dev_archdata to keep the dma_ops per device. The pci devices now use that to override the default, and the default is changed to use the noop ops for everything that does not specify a device specific one. To compile without PCI support we will enable HAS_DMA all the time, via the default config in lib/Kconfig. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Joerg Roedel <jroedel@suse.de> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* alpha/dma: use common noop dma opsChristian Borntraeger2016-03-02
| | | | | | | | | | Some of the alpha pci noop dma ops are identical to the common ones. Use them. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* dma: Provide simple noop dma opsChristian Borntraeger2016-03-02
| | | | | | | | | | | We are going to require dma_ops for several common drivers, even for systems that do have an identity mapping. Lets provide some minimal no-op dma_ops that can be used for that purpose. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: fix error path in vhost_init_used()Greg Kurz2016-03-02
| | | | | | | | We don't want side effects. If something fails, we rollback vq->is_le to its previous value. Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio-pci: read the right virtio_pci_notify_cap fieldLadi Prosek2016-03-02
| | | | | | | | | | | | | Looks like a copy-paste bug. The value is used as an optimization and a wrong value probably isn't causing any serious damage. Found when porting this code to Windows. Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* Linux 4.5-rc6Linus Torvalds2016-02-28
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* Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2016-02-28
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "A rather largish series of 12 patches addressing a maze of race conditions in the perf core code from Peter Zijlstra" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Robustify task_function_call() perf: Fix scaling vs. perf_install_in_context() perf: Fix scaling vs. perf_event_enable() perf: Fix scaling vs. perf_event_enable_on_exec() perf: Fix ctx time tracking by introducing EVENT_TIME perf: Cure event->pending_disable race perf: Fix race between event install and jump_labels perf: Fix cloning perf: Only update context time when active perf: Allow perf_release() with !event->ctx perf: Do not double free perf: Close install vs. exit race
| * perf: Robustify task_function_call()Peter Zijlstra2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since there is no serialization between task_function_call() doing task_curr() and the other CPU doing context switches, we could end up not sending an IPI even if we had to. And I'm not sure I still buy my own argument we're OK. 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: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174948.340031200@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Fix scaling vs. perf_install_in_context()Peter Zijlstra2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Completely reworks perf_install_in_context() (again!) in order to ensure that there will be no ctx time hole between add_event_to_ctx() and any potential ctx_sched_in(). 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: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174948.279399438@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Fix scaling vs. perf_event_enable()Peter Zijlstra2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similar to the perf_enable_on_exec(), ensure that event timings are consistent across perf_event_enable(). 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: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174948.218288698@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Fix scaling vs. perf_event_enable_on_exec()Peter Zijlstra2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent commit 3e349507d12d ("perf: Fix perf_enable_on_exec() event scheduling") caused this by moving task_ctx_sched_out() from before __perf_event_mask_enable() to after it. The overlooked consequence of that change is that task_ctx_sched_out() would update the ctx time fields, and now __perf_event_mask_enable() uses stale time. In order to fix this, explicitly stop our context's time before enabling the event(s). Reported-by: Oleg Nesterov <oleg@redhat.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: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Fixes: 3e349507d12d ("perf: Fix perf_enable_on_exec() event scheduling") Link: http://lkml.kernel.org/r/20160224174948.159242158@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Fix ctx time tracking by introducing EVENT_TIMEPeter Zijlstra2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently any ctx_sched_in() call will re-start the ctx time tracking, this means that calls like: ctx_sched_in(.event_type = EVENT_PINNED); ctx_sched_in(.event_type = EVENT_FLEXIBLE); will have a hole in their ctx time tracking. This is likely harmless but can confuse things a little. By adding EVENT_TIME, we can have the first ctx_sched_in() (is_active: 0 -> !0) start the time and any further ctx_sched_in() will leave the timestamps alone. Secondly, this allows for an early disable like: ctx_sched_out(.event_type = EVENT_TIME); which would update the ctx time (if the ctx is active) and any further calls to ctx_sched_out() would not further modify the ctx time. For ctx_sched_in() any 0 -> !0 transition will automatically include EVENT_TIME. For ctx_sched_out(), any transition that clears EVENT_ALL will automatically clear EVENT_TIME. These two rules ensure that under normal circumstances we need not bother with EVENT_TIME and get natural ctx time behaviour. 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: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174948.100446561@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Cure event->pending_disable racePeter Zijlstra2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because event_sched_out() checks event->pending_disable _before_ actually disabling the event, it can happen that the event fires after it checks but before it gets disabled. This would leave event->pending_disable set and the queued irq_work will try and process it. However, if the event trigger was during schedule(), the event might have been de-scheduled by the time the irq_work runs, and perf_event_disable_local() will fail. Fix this by checking event->pending_disable _after_ we call event->pmu->del(). This depends on the latter being a compiler barrier, such that the compiler does not lift the load and re-creates the problem. Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: 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: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174948.040469884@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Fix race between event install and jump_labelsPeter Zijlstra2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | perf_install_in_context() relies upon the context switch hooks to have scheduled in events when the IPI misses its target -- after all, if the task has moved from the CPU (or wasn't running at all), it will have to context switch to run elsewhere. This however doesn't appear to be happening. It is possible for the IPI to not happen (task wasn't running) only to later observe the task running with an inactive context. The only possible explanation is that the context switch hooks are not called. Therefore put in a sync_sched() after toggling the jump_label to guarantee all CPUs will have them enabled before we install an event. A simple if (0->1) sync_sched() will not in fact work, because any further increment can race and complete before the sync_sched(). Therefore we must jump through some hoops. 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: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174947.980211985@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Fix cloningPeter Zijlstra2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexander reported that when the 'original' context gets destroyed, no new clones happen. This can happen irrespective of the ctx switch optimization, any task can die, even the parent, and we want to continue monitoring the task hierarchy until we either close the event or no tasks are left in the hierarchy. perf_event_init_context() will attempt to pin the 'parent' context during clone(). At that point current is the parent, and since current cannot have exited while executing clone(), its context cannot have passed through perf_event_exit_task_context(). Therefore perf_pin_task_context() cannot observe ctx->task == TASK_TOMBSTONE. However, since inherit_event() does: if (parent_event->parent) parent_event = parent_event->parent; it looks at the 'original' event when it does: is_orphaned_event(). This can return true if the context that contains the this event has passed through perf_event_exit_task_context(). And thus we'll fail to clone the perf context. Fix this by adding a new state: STATE_DEAD, which is set by perf_release() to indicate that the filedesc (or kernel reference) is dead and there are no observers for our data left. Only for STATE_DEAD will is_orphaned_event() be true and inhibit cloning. STATE_EXIT is otherwise preserved such that is_event_hup() remains functional and will report when the observed task hierarchy becomes empty. Reported-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: 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: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Fixes: c6e5b73242d2 ("perf: Synchronously clean up child events") Link: http://lkml.kernel.org/r/20160224174947.919845295@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Only update context time when activePeter Zijlstra2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174947.860690919@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Allow perf_release() with !event->ctxPeter Zijlstra2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the err_file: fput(event_file) case, the event will not yet have been attached to a context. However perf_release() does assume it has been. Cure this. Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: 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: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174947.793996260@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Do not double freePeter Zijlstra2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case of: err_file: fput(event_file), we'll end up calling perf_release() which in turn will free the event. Do not then free the event _again_. Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: 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: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174947.697350349@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Close install vs. exit racePeter Zijlstra2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Consider the following scenario: CPU0 CPU1 ctx = find_get_ctx(); perf_event_exit_task_context() mutex_lock(&ctx->mutex); perf_install_in_context(ctx, ...); /* NO-OP */ mutex_unlock(&ctx->mutex); ... perf_release() WARN_ON_ONCE(event->state != STATE_EXIT); Since the event doesn't pass through perf_remove_from_context() because perf_install_in_context() NO-OPs because the ctx is dead, and perf_event_exit_task_context() will not observe the event because its not attached yet, the event->state will not be set. Solve this by revalidating ctx->task after we acquire ctx->mutex and failing the event creation as a whole. Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: 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: Thomas Gleixner <tglx@linutronix.de> Cc: dvyukov@google.com Cc: eranian@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160224174947.626853419@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2016-02-28
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "This update contains: - Hopefully the last ASM CLAC fixups - A fix for the Quark family related to the IMR lock which makes kexec work again - A off-by-one fix in the MPX code. Ironic, isn't it? - A fix for X86_PAE which addresses once more an unsigned long vs phys_addr_t hickup" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mpx: Fix off-by-one comparison with nr_registers x86/mm: Fix slow_virt_to_phys() for X86_PAE again x86/entry/compat: Add missing CLAC to entry_INT80_32 x86/entry/32: Add an ASM_CLAC to entry_SYSENTER_32 x86/platform/intel/quark: Change the kernel's IMR lock bit to false
| * | x86/mpx: Fix off-by-one comparison with nr_registersColin Ian King2016-02-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the unlikely event that regno == nr_registers then we get an array overrun on regoff because the invalid register check is currently off-by-one. Fix this with a check that regno is >= nr_registers instead. Detected with static analysis using CoverityScan. Fixes: fcc7ffd67991 "x86, mpx: Decode MPX instruction to get bound violation information" Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1456512931-3388-1-git-send-email-colin.king@canonical.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | x86/mm: Fix slow_virt_to_phys() for X86_PAE againDexuan Cui2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "d1cd12108346: x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE" was unintentionally removed by the recent "34437e67a672: x86/mm: Fix slow_virt_to_phys() to handle large PAT bit". And, the variable 'phys_addr' was defined as "unsigned long" by mistake -- it should be "phys_addr_t". As a result, Hyper-V network driver in 32-PAE Linux guest can't work again. Fixes: commit 34437e67a672: "x86/mm: Fix slow_virt_to_phys() to handle large PAT bit" Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Toshi Kani <toshi.kani@hpe.com> Cc: olaf@aepfle.de Cc: gregkh@linuxfoundation.org Cc: jasowang@redhat.com Cc: driverdev-devel@linuxdriverproject.org Cc: linux-mm@kvack.org Cc: apw@canonical.com Cc: Andrew Morton <akpm@linux-foundation.org> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Link: http://lkml.kernel.org/r/1456394292-9030-1-git-send-email-decui@microsoft.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | x86/entry/compat: Add missing CLAC to entry_INT80_32Andy Lutomirski2016-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This doesn't seem to fix a regression -- I don't think the CLAC was ever there. I double-checked in a debugger: entries through the int80 gate do not automatically clear AC. Stable maintainers: I can provide a backport to 4.3 and earlier if needed. This needs to be backported all the way to 3.10. Reported-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> # v3.10 and later Fixes: 63bcff2a307b ("x86, smap: Add STAC and CLAC instructions to control user space access") Link: http://lkml.kernel.org/r/b02b7e71ae54074be01fc171cbd4b72517055c0e.1456345086.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/entry/32: Add an ASM_CLAC to entry_SYSENTER_32Andy Lutomirski2016-02-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both before and after 5f310f739b4c ("x86/entry/32: Re-implement SYSENTER using the new C path"), we relied on a uaccess very early in the SYSENTER path to clear AC. After that change, though, we can potentially make it all the way into C code with AC set, which enlarges the attack surface for SMAP bypass by doing SYSENTER with AC set. Strengthen the SMAP protection by addding the missing ASM_CLAC right at the beginning. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> 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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/3e36be110724896e32a4a1fe73bacb349d3cba94.1456262295.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/platform/intel/quark: Change the kernel's IMR lock bit to falseBryan O'Donoghue2016-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently when setting up an IMR around the kernel's .text section we lock that IMR, preventing further modification. While superficially this appears to be the right thing to do, in fact this doesn't account for a legitimate change in the memory map such as when executing a new kernel via kexec. In such a scenario a second kernel can have a different size and location to it's predecessor and can view some of the memory occupied by it's predecessor as legitimately usable DMA RAM. If this RAM were then subsequently allocated to DMA agents within the system it could conceivably trigger an IMR violation. This patch fixes the this potential situation by keeping the kernel's .text section IMR lock bit false by default. Suggested-by: Ingo Molnar <mingo@kernel.org> Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boon.leong.ong@intel.com Cc: paul.gortmaker@windriver.com Link: http://lkml.kernel.org/r/1456190999-12685-2-git-send-email-pure.logic@nexus-software.ie Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2016-02-28
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixlet from Thomas Gleixner: "A trivial printk typo fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/deadline: Fix trivial typo in printk() message
| * | | sched/deadline: Fix trivial typo in printk() messageSteven Rostedt2016-02-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's "too much" not "to much". Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Juri Lelli <juri.lelli@arm.com> Cc: Jiri Kosina <trivial@kernel.org> Cc: Juri Lelli <juri.lelli@gmail.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/20160210120422.4ca77e68@gandalf.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds2016-02-28
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "Four small fixes for irqchip drivers: - Add missing low level irq handler initialization on mxs, so interrupts can acutally be delivered - Add a missing barrier to the GIC driver - Two fixes for the GIC-V3-ITS driver, addressing a double EOI write and a cache flush beyond the actual region" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/gic-v3: Add missing barrier to 32bit version of gic_read_iar() irqchip/mxs: Add missing set_handle_irq() irqchip/gicv3-its: Avoid cache flush beyond ITS_BASERn memory size irqchip/gic-v3-its: Fix double ICC_EOIR write for LPI in EOImode==1
| * \ \ \ Merge tag 'gic-fixes-4.5-rc5' of ↵Thomas Gleixner2016-02-22
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent Pull GIC fixes for 4.5-rc5 from Marc Zyngier: - EOI handling for LPIs when GICv3 is in EOImode==1 - Another fallout from changing page size while allocating ITS tables - Missing memory barrier in the 32bit GICv3 code
| | * | | | irqchip/gic-v3: Add missing barrier to 32bit version of gic_read_iar()Marc Zyngier2016-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 1a1ebd5 ("irqchip/gic-v3: Make sure read from ICC_IAR1_EL1 is visible on redestributor") fixed the missing barrier on arm64, but forgot to update the 32bit counterpart, which has the same requirements. Let's fix it. Fixes: 1a1ebd5 ("irqchip/gic-v3: Make sure read from ICC_IAR1_EL1 is visible on redestributor") Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * | | | irqchip/gicv3-its: Avoid cache flush beyond ITS_BASERn memory sizeShanker Donthineni2016-02-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Function its_alloc_tables() maintains two local variables, "order" and and "alloc_size", to hold memory size that has been allocated to ITS_BASEn. We don't always refresh the variable alloc_size whenever value of the variable order changes, causing the following two problems. - Cache flush operation with size more than required. - Information reported by pr_info is not correct. Use a helper macro that converts page order to size in bytes instead of variable "alloc_size" to fix both the problems. Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * | | | irqchip/gic-v3-its: Fix double ICC_EOIR write for LPI in EOImode==1Ashok Kumar2016-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the GIC is using EOImode==1, the EOI is done immediately, leaving the deactivation to be performed when the EOI was previously done. Unfortunately, the ITS is not aware of the EOImode at all, and blindly EOIs the interrupt again. On most systems, this is ignored (despite being a programming error), but some others do raise a SError exception as there is no priority drop to perform for this interrupt. The fix is to stop trying to be clever, and always call into the underlying GIC to perform the right access, irrespective of the more we're in. [Marc: Reworked commit message] Fixes: 0b996fd35957a ("irqchip/GICv3: Convert to EOImode == 1") Cc: stable@vger.kernel.org Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ashok Kumar <ashoks@broadcom.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| * | | | | Merge tag 'irqchip-urgent-4.5' of ↵Thomas Gleixner2016-02-21
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.infradead.org/users/jcooper/linux into irq/urgent Pull irqchip fixes for v4.5 from Jason Cooper: - mxs: Add a missing set_handle_irq()
| | * | | | | irqchip/mxs: Add missing set_handle_irq()Oleksij Rempel2016-02-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The rework of the driver missed to move the call to set_handle_irq() into asm9260_of_init(). As a consequence no interrupt entry point is installed and no interrupts are delivered Solution is: Install the interrupt entry handler. Fixes: 7e4ac676ee ("irqchip/mxs: Add Alphascale ASM9260 support") Signed-off-by: Oleksij Rempel <linux@rempel-privat.de> Link: https://lkml.kernel.org/r/1454061473-24957-1-git-send-email-linux@rempel-privat.de Signed-off-by: Jason Cooper <jason@lakedaemon.net>
* | | | | | | Merge tag 'staging-4.5-rc6' of ↵Linus Torvalds2016-02-28
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging Pull staging/android fix from Greg KH: "Here is one patch, for the android binder driver, to resolve a reported problem. Turns out it has been around for a while (since 3.15), so it is good to finally get it resolved. It has been in linux-next for a while with no reported issues" * tag 'staging-4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: drivers: android: correct the size of struct binder_uintptr_t for BC_DEAD_BINDER_DONE