- 11 6月, 2019 12 次提交
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由 Suren Baghdasaryan 提交于
commit 33b2d6302abc4ccea1d9b3f095e2e27b02ca264e upstream. Patch series "psi: pressure stall monitors", v6. This is a respin of: https://lwn.net/ml/linux-kernel/20190308184311.144521-1-surenb%40google.com/ Android is adopting psi to detect and remedy memory pressure that results in stuttering and decreased responsiveness on mobile devices. Psi gives us the stall information, but because we're dealing with latencies in the millisecond range, periodically reading the pressure files to detect stalls in a timely fashion is not feasible. Psi also doesn't aggregate its averages at a high-enough frequency right now. This patch series extends the psi interface such that users can configure sensitive latency thresholds and use poll() and friends to be notified when these are breached. As high-frequency aggregation is costly, it implements an aggregation method that is optimized for fast, short-interval averaging, and makes the aggregation frequency adaptive, such that high-frequency updates only happen while monitored stall events are actively occurring. With these patches applied, Android can monitor for, and ward off, mounting memory shortages before they cause problems for the user. For example, using memory stall monitors in userspace low memory killer daemon (lmkd) we can detect mounting pressure and kill less important processes before device becomes visibly sluggish. In our memory stress testing psi memory monitors produce roughly 10x less false positives compared to vmpressure signals. Having ability to specify multiple triggers for the same psi metric allows other parts of Android framework to monitor memory state of the device and act accordingly. The new interface is straight-forward. The user opens one of the pressure files for writing and writes a trigger description into the file descriptor that defines the stall state - some or full, and the maximum stall time over a given window of time. E.g.: /* Signal when stall time exceeds 100ms of a 1s window */ char trigger[] = "full 100000 1000000" fd = open("/proc/pressure/memory") write(fd, trigger, sizeof(trigger)) while (poll() >= 0) { ... }; close(fd); When the monitored stall state is entered, psi adapts its aggregation frequency according to what the configured time window requires in order to emit event signals in a timely fashion. Once the stalling subsides, aggregation reverts back to normal. The trigger is associated with the open file descriptor. To stop monitoring, the user only needs to close the file descriptor and the trigger is discarded. Patches 1-6 prepare the psi code for polling support. Patch 7 implements the adaptive polling logic, the pressure growth detection optimized for short intervals, and hooks up write() and poll() on the pressure files. The patches were developed in collaboration with Johannes Weiner. This patch (of 7): The psi monitoring patches will need to determine the same states as record_times(). To avoid calculating them twice, maintain a state mask that can be consulted cheaply. Do this in a separate patch to keep the churn in the main feature patch at a minimum. This adds 4-byte state_mask member into psi_group_cpu struct which results in its first cacheline-aligned part becoming 52 bytes long. Add explicit values to enumeration element counters that affect psi_group_cpu struct size. Link: http://lkml.kernel.org/r/20190124211518.244221-4-surenb@google.comSigned-off-by: NSuren Baghdasaryan <surenb@google.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Dennis Zhou <dennis@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Li Zefan <lizefan@huawei.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
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由 Johannes Weiner 提交于
commit 4e37504d1c49eec6434d0cc97278d2b51c9e8763 upstream. We've been seeing hard-to-trigger psi crashes when running inside VM instances: divide error: 0000 [#1] SMP PTI Modules linked in: [...] CPU: 0 PID: 212 Comm: kworker/0:2 Not tainted 4.16.18-119_fbk9_3817_gfe944c98d695 #119 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 Workqueue: events psi_clock RIP: 0010:psi_update_stats+0x270/0x490 RSP: 0018:ffffc90001117e10 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8800a35a13f8 RDX: 0000000000000000 RSI: ffff8800a35a1340 RDI: 0000000000000000 RBP: 0000000000000658 R08: ffff8800a35a1470 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00000000000f8502 FS: 0000000000000000(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbe370fa000 CR3: 00000000b1e3a000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: psi_clock+0x12/0x50 process_one_work+0x1e0/0x390 worker_thread+0x2b/0x3c0 ? rescuer_thread+0x330/0x330 kthread+0x113/0x130 ? kthread_create_worker_on_cpu+0x40/0x40 ? SyS_exit_group+0x10/0x10 ret_from_fork+0x35/0x40 Code: 48 0f 47 c7 48 01 c2 45 85 e4 48 89 16 0f 85 e6 00 00 00 4c 8b 49 10 4c 8b 51 08 49 69 d9 f2 07 00 00 48 6b c0 64 4c 8b 29 31 d2 <48> f7 f7 49 69 d5 8d 06 00 00 48 89 c5 4c 69 f0 00 98 0b 00 48 The Code-line points to `period` being 0 inside update_stats(), and we divide by that when calculating that period's pressure percentage. The elapsed period should never be 0. The reason this can happen is due to an off-by-one in the idle time / missing period calculation combined with a coarse sched_clock() in the virtual machine. The target time for aggregation is advanced into the future on a fixed grid to prevent clock drift. So when an aggregation runs after some idle period, we can not just set it to "now + psi_period", but have to calculate the downtime and advance the target time relative to itself. However, if the aggregator was disabled exactly one psi_period (ns), we drop one idle period in the calculation due to a > when we should do >=. In that case, next_update will be advanced from 'now - psi_period' to 'now' when it should be moved to 'now + psi_period'. The run finishes with last_update == next_update == sched_clock(). With hardware clocks, this exact nanosecond match isn't likely in the first place; but if it does happen, the clock will still have moved on and the period non-zero by the time the worker runs. A pointlessly short period, but besides the extra work, no harm no foul. However, a slow sched_clock() like we have on VMs might not have advanced either by the time the worker runs again. And when we calculate the elapsed period, the result, our pressure divisor, will be 0. Ouch. Fix this by correctly handling the situation when the elapsed time between aggregation runs is precisely two periods, and advance the expiration timestamp correctly to period into the future. Link: http://lkml.kernel.org/r/20190214193157.15788-1-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Reported-by: Łukasz Siudut <lsiudut@fb.com Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
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由 Johannes Weiner 提交于
commit 1b69ac6b40ebd85eed73e4dbccde2a36961ab990 upstream. psi has provisions to shut off the periodic aggregation worker when there is a period of no task activity - and thus no data that needs aggregating. However, while developing psi monitoring, Suren noticed that the aggregation clock currently won't stay shut off for good. Debugging this revealed a flaw in the idle design: an aggregation run will see no task activity and decide to go to sleep; shortly thereafter, the kworker thread that executed the aggregation will go idle and cause a scheduling change, during which the psi callback will kick the !pending worker again. This will ping-pong forever, and is equivalent to having no shut-off logic at all (but with more code!) Fix this by exempting aggregation workers from psi's clock waking logic when the state change is them going to sleep. To do this, tag workers with the last work function they executed, and if in psi we see a worker going to sleep after aggregating psi data, we will not reschedule the aggregation work item. What if the worker is also executing other items before or after? Any psi state times that were incurred by work items preceding the aggregation work will have been collected from the per-cpu buckets during the aggregation itself. If there are work items following the aggregation work, the worker's last_func tag will be overwritten and the aggregator will be kept alive to process this genuine new activity. If the aggregation work is the last thing the worker does, and we decide to go idle, the brief period of non-idle time incurred between the aggregation run and the kworker's dequeue will be stranded in the per-cpu buckets until the clock is woken by later activity. But that should not be a problem. The buckets can hold 4s worth of time, and future activity will wake the clock with a 2s delay, giving us 2s worth of data we can leave behind when disabling aggregation. If it takes a worker more than two seconds to go idle after it finishes its last work item, we likely have bigger problems in the system, and won't notice one sample that was averaged with a bogus per-CPU weight. Link: http://lkml.kernel.org/r/20190116193501.1910-1-hannes@cmpxchg.org Fixes: eb414681d5a0 ("psi: pressure stall information for CPU, memory, and IO") Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Reported-by: NSuren Baghdasaryan <surenb@google.com> Acked-by: NTejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
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由 Johannes Weiner 提交于
commit e0c274472d5d27f277af722e017525e0b33784cd upstream. Mel Gorman reports a hackbench regression with psi that would prohibit shipping the suse kernel with it default-enabled, but he'd still like users to be able to opt in at little to no cost to others. With the current combination of CONFIG_PSI and the psi_disabled bool set from the commandline, this is a challenge. Do the following things to make it easier: 1. Add a config option CONFIG_PSI_DEFAULT_DISABLED that allows distros to enable CONFIG_PSI in their kernel but leave the feature disabled unless a user requests it at boot-time. To avoid double negatives, rename psi_disabled= to psi=. 2. Make psi_disabled a static branch to eliminate any branch costs when the feature is disabled. In terms of numbers before and after this patch, Mel says: : The following is a comparision using CONFIG_PSI=n as a baseline against : your patch and a vanilla kernel : : 4.20.0-rc4 4.20.0-rc4 4.20.0-rc4 : kconfigdisable-v1r1 vanilla psidisable-v1r1 : Amean 1 1.3100 ( 0.00%) 1.3923 ( -6.28%) 1.3427 ( -2.49%) : Amean 3 3.8860 ( 0.00%) 4.1230 * -6.10%* 3.8860 ( -0.00%) : Amean 5 6.8847 ( 0.00%) 8.0390 * -16.77%* 6.7727 ( 1.63%) : Amean 7 9.9310 ( 0.00%) 10.8367 * -9.12%* 9.9910 ( -0.60%) : Amean 12 16.6577 ( 0.00%) 18.2363 * -9.48%* 17.1083 ( -2.71%) : Amean 18 26.5133 ( 0.00%) 27.8833 * -5.17%* 25.7663 ( 2.82%) : Amean 24 34.3003 ( 0.00%) 34.6830 ( -1.12%) 32.0450 ( 6.58%) : Amean 30 40.0063 ( 0.00%) 40.5800 ( -1.43%) 41.5087 ( -3.76%) : Amean 32 40.1407 ( 0.00%) 41.2273 ( -2.71%) 39.9417 ( 0.50%) : : It's showing that the vanilla kernel takes a hit (as the bisection : indicated it would) and that disabling PSI by default is reasonably : close in terms of performance for this particular workload on this : particular machine so; Link: http://lkml.kernel.org/r/20181127165329.GA29728@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Tested-by: NMel Gorman <mgorman@techsingularity.net> Reported-by: NMel Gorman <mgorman@techsingularity.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
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由 Olof Johansson 提交于
commit 8fcb2312d1e3300e81aa871aad00d4c038cfc184 upstream. The existing code triggered an invalid warning about 'rq' possibly being used uninitialized. Instead of doing the silly warning suppression by initializa it to NULL, refactor the code to bail out early instead. Warning was: kernel/sched/psi.c: In function `cgroup_move_task': kernel/sched/psi.c:639:13: warning: `rq' may be used uninitialized in this function [-Wmaybe-uninitialized] Link: http://lkml.kernel.org/r/20181103183339.8669-1-olof@lixom.net Fixes: 2ce7135adc9ad ("psi: cgroup support") Signed-off-by: NOlof Johansson <olof@lixom.net> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
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由 Johannes Weiner 提交于
commit 2ce7135adc9ad081aa3c49744144376ac74fea60 upstream. On a system that executes multiple cgrouped jobs and independent workloads, we don't just care about the health of the overall system, but also that of individual jobs, so that we can ensure individual job health, fairness between jobs, or prioritize some jobs over others. This patch implements pressure stall tracking for cgroups. In kernels with CONFIG_PSI=y, cgroup2 groups will have cpu.pressure, memory.pressure, and io.pressure files that track aggregate pressure stall times for only the tasks inside the cgroup. Link: http://lkml.kernel.org/r/20180828172258.3185-10-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NTejun Heo <tj@kernel.org> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Tested-by: NDaniel Drake <drake@endlessm.com> Tested-by: NSuren Baghdasaryan <surenb@google.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
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由 Johannes Weiner 提交于
commit eb414681d5a07d28d2ff90dc05f69ec6b232ebd2 upstream. When systems are overcommitted and resources become contended, it's hard to tell exactly the impact this has on workload productivity, or how close the system is to lockups and OOM kills. In particular, when machines work multiple jobs concurrently, the impact of overcommit in terms of latency and throughput on the individual job can be enormous. In order to maximize hardware utilization without sacrificing individual job health or risk complete machine lockups, this patch implements a way to quantify resource pressure in the system. A kernel built with CONFIG_PSI=y creates files in /proc/pressure/ that expose the percentage of time the system is stalled on CPU, memory, or IO, respectively. Stall states are aggregate versions of the per-task delay accounting delays: cpu: some tasks are runnable but not executing on a CPU memory: tasks are reclaiming, or waiting for swapin or thrashing cache io: tasks are waiting for io completions These percentages of walltime can be thought of as pressure percentages, and they give a general sense of system health and productivity loss incurred by resource overcommit. They can also indicate when the system is approaching lockup scenarios and OOMs. To do this, psi keeps track of the task states associated with each CPU and samples the time they spend in stall states. Every 2 seconds, the samples are averaged across CPUs - weighted by the CPUs' non-idle time to eliminate artifacts from unused CPUs - and translated into percentages of walltime. A running average of those percentages is maintained over 10s, 1m, and 5m periods (similar to the loadaverage). [hannes@cmpxchg.org: doc fixlet, per Randy] Link: http://lkml.kernel.org/r/20180828205625.GA14030@cmpxchg.org [hannes@cmpxchg.org: code optimization] Link: http://lkml.kernel.org/r/20180907175015.GA8479@cmpxchg.org [hannes@cmpxchg.org: rename psi_clock() to psi_update_work(), per Peter] Link: http://lkml.kernel.org/r/20180907145404.GB11088@cmpxchg.org [hannes@cmpxchg.org: fix build] Link: http://lkml.kernel.org/r/20180913014222.GA2370@cmpxchg.org Link: http://lkml.kernel.org/r/20180828172258.3185-9-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Tested-by: NDaniel Drake <drake@endlessm.com> Tested-by: NSuren Baghdasaryan <surenb@google.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
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由 Johannes Weiner 提交于
commit 246b3b3342c9b0a2e24cda2178be87bc36e1c874 upstream. do_sched_yield() disables IRQs, looks up this_rq() and locks it. The next patch is adding another site with the same pattern, so provide a convenience function for it. Link: http://lkml.kernel.org/r/20180828172258.3185-8-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Tested-by: NSuren Baghdasaryan <surenb@google.com> Tested-by: NDaniel Drake <drake@endlessm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
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由 Johannes Weiner 提交于
commit 1f351d7f7590857ea281579c26e6045b4c548ef4 upstream. kernel/sched/sched.h includes "stats.h" half-way through the file. The next patch introduces users of sched.h's rq locking functions and update_rq_clock() in kernel/sched/stats.h. Move those definitions up in the file so they are available in stats.h. Link: http://lkml.kernel.org/r/20180828172258.3185-7-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Tested-by: NSuren Baghdasaryan <surenb@google.com> Tested-by: NDaniel Drake <drake@endlessm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
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由 Johannes Weiner 提交于
commit 5c54f5b9edb1aa2eabbb1091c458f1b6776a1896 upstream. It's going to be used in a later patch. Keep the churn separate. Link: http://lkml.kernel.org/r/20180828172258.3185-6-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Tested-by: NSuren Baghdasaryan <surenb@google.com> Tested-by: NDaniel Drake <drake@endlessm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
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由 Johannes Weiner 提交于
commit 8508cf3ffad4defa202b303e5b6379efc4cd9054 upstream. There are several definitions of those functions/macros in places that mess with fixed-point load averages. Provide an official version. [akpm@linux-foundation.org: fix missed conversion in block/blk-iolatency.c] Link: http://lkml.kernel.org/r/20180828172258.3185-5-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Tested-by: NSuren Baghdasaryan <surenb@google.com> Tested-by: NDaniel Drake <drake@endlessm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
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由 Johannes Weiner 提交于
commit b1d29ba82cf2bc784f4c963ddd6a2cf29e229b33 upstream. Delay accounting already measures the time a task spends in direct reclaim and waiting for swapin, but in low memory situations tasks spend can spend a significant amount of their time waiting on thrashing page cache. This isn't tracked right now. To know the full impact of memory contention on an individual task, measure the delay when waiting for a recently evicted active cache page to read back into memory. Also update tools/accounting/getdelays.c: [hannes@computer accounting]$ sudo ./getdelays -d -p 1 print delayacct stats ON PID 1 CPU count real total virtual total delay total delay average 50318 745000000 847346785 400533713 0.008ms IO count delay total delay average 435 122601218 0ms SWAP count delay total delay average 0 0 0ms RECLAIM count delay total delay average 0 0 0ms THRASHING count delay total delay average 19 12621439 0ms Link: http://lkml.kernel.org/r/20180828172258.3185-4-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Tested-by: NDaniel Drake <drake@endlessm.com> Tested-by: NSuren Baghdasaryan <surenb@google.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
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- 04 6月, 2019 3 次提交
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由 George Zhang 提交于
By default the tcp_tw_timeout value is 60 seconds. The minimum is 1 second and the maximum is 600. This setting is useful on system under heavy tcp load. NOTE: set the tcp_tw_timeout below 60 seconds voilates the "quiet time" restriction, and make your system into the risk of causing some old data to be accepted as new or new data rejected as old duplicated by some receivers. Link: http://web.archive.org/web/20150102003320/http://tools.ietf.org/html/rfc793Signed-off-by: NGeorge Zhang <georgezhang@linux.alibaba.com> Signed-off-by: NJiufei Xue <jiufei.xue@linux.alibaba.com> Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
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由 Jiufei Xue 提交于
Here we add a global radix tree to link memcg and blkcg that the user attach the tasks to when using cgroup v1, which is used for writeback cgroup. Signed-off-by: NJiufei Xue <jiufei.xue@linux.alibaba.com> Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
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由 Masahiro Yamada 提交于
commit e9666d10a5677a494260d60d1fa0b73cc7646eb3 upstream. Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: NSedat Dilek <sedat.dilek@gmail.com> [nc: Fix trivial conflicts in 4.19 arch/xtensa/kernel/jump_label.c doesn't exist yet Ensured CC_HAVE_ASM_GOTO and HAVE_JUMP_LABEL were sufficiently eliminated] Signed-off-by: NNathan Chancellor <natechancellor@gmail.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 31 5月, 2019 15 次提交
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由 Paul E. McKenney 提交于
[ Upstream commit ad092c027713a68a34168942a5ef422e42e039f4 ] If the specified rcuperf.perf_type is not in the rcu_perf_init() function's perf_ops[] array, rcuperf prints some console messages and then invokes rcu_perf_cleanup() to set state so that a future torture test can run. However, rcu_perf_cleanup() also attempts to end the test that didn't actually start, and in doing so relies on the value of cur_ops, a value that is not particularly relevant in this case. This can result in confusing output or even follow-on failures due to attempts to use facilities that have not been properly initialized. This commit therefore sets the value of cur_ops to NULL in this case and inserts a check near the beginning of rcu_perf_cleanup(), thus avoiding relying on an irrelevant cur_ops value. Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Paul E. McKenney 提交于
[ Upstream commit b813afae7ab6a5e91b4e16cc567331d9c2ae1f04 ] If the specified rcutorture.torture_type is not in the rcu_torture_init() function's torture_ops[] array, rcutorture prints some console messages and then invokes rcu_torture_cleanup() to set state so that a future torture test can run. However, rcu_torture_cleanup() also attempts to end the test that didn't actually start, and in doing so relies on the value of cur_ops, a value that is not particularly relevant in this case. This can result in confusing output or even follow-on failures due to attempts to use facilities that have not been properly initialized. This commit therefore sets the value of cur_ops to NULL in this case and inserts a check near the beginning of rcu_torture_cleanup(), thus avoiding relying on an irrelevant cur_ops value. Reported-by: Nkernel test robot <rong.a.chen@intel.com> Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Thomas Gleixner 提交于
[ Upstream commit 7a8e61f8478639072d402a26789055a4a4de8f77 ] Several people reported testing failures after setting CLOCK_REALTIME close to the limits of the kernel internal representation in nanoseconds, i.e. year 2262. The failures are exposed in subsequent operations, i.e. when arming timers or when the advancing CLOCK_MONOTONIC makes the calculation of CLOCK_REALTIME overflow into negative space. Now people start to paper over the underlying problem by clamping calculations to the valid range, but that's just wrong because such workarounds will prevent detection of real issues as well. It is reasonable to force an upper bound for the various methods of setting CLOCK_REALTIME. Year 2262 is the absolute upper bound. Assume a maximum uptime of 30 years which is plenty enough even for esoteric embedded systems. That results in an upper bound of year 2232 for setting the time. Once that limit is reached in reality this limit is only a small part of the problem space. But until then this stops people from trying to paper over the problem at the wrong places. Reported-by: NXiongfeng Wang <wangxiongfeng2@huawei.com> Reported-by: NHongbo Yao <yaohongbo@huawei.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Miroslav Lichvar <mlichvar@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1903231125480.2157@nanos.tec.linutronix.deSigned-off-by: NSasha Levin <sashal@kernel.org>
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由 Peter Zijlstra 提交于
[ Upstream commit 4a6c91fbdef846ec7250b82f2eeeb87ac5f18cf9 ] For CONFIG_TRACE_BRANCH_PROFILING=y the likely/unlikely things get overloaded and generate callouts to this code, and thus also when AC=1. Make it safe. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Nicholas Piggin 提交于
[ Upstream commit 471ba0e686cb13752bc1ff3216c54b69a2d250ea ] The QEMU PowerPC/PSeries machine model was not expecting a self-IPI, and it may be a bit surprising thing to do, so have irq_work_queue_on do local queueing when target is the current CPU. Suggested-by: NSteven Rostedt <rostedt@goodmis.org> Reported-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: NNicholas Piggin <npiggin@gmail.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NFrederic Weisbecker <frederic@kernel.org> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@kaod.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190409093403.20994-1-npiggin@gmail.com [ Simplified the preprocessor comments. Fixed unbalanced curly brackets pointed out by Thomas. ] Signed-off-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Konstantin Khlebnikov 提交于
[ Upstream commit 5b61d50ab4ef590f5e1d4df15cd2cea5f5715308 ] Bit shift in scale_load() could overflow shares. This patch saturates it to MAX_SHARES like following sched_group_set_shares(). Example: # echo 9223372036854776832 > cpu.shares # cat cpu.shares Before patch: 1024 After pattch: 262144 Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> 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/155125501891.293431.3345233332801109696.stgit@buzzSigned-off-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Konstantin Khlebnikov 提交于
[ Upstream commit 1a010e29cfa00fee2888fd2fd4983f848cbafb58 ] Example of unhandled overflows: # echo 18446744073709651 > cpu.rt_runtime_us # cat cpu.rt_runtime_us 99 # echo 18446744073709900 > cpu.rt_period_us # cat cpu.rt_period_us 348 After this patch they will fail with -EINVAL. Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> 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/155125501739.293431.5252197504404771496.stgit@buzzSigned-off-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Konstantin Khlebnikov 提交于
[ Upstream commit 1a8b4540db732ca16c9e43ac7c08b1b8f0b252d8 ] Large values could overflow u64 and pass following sanity checks. # echo 18446744073750000 > cpu.cfs_period_us # cat cpu.cfs_period_us 40448 # echo 18446744073750000 > cpu.cfs_quota_us # cat cpu.cfs_quota_us 40448 After this patch they will fail with -EINVAL. Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> 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/155125502079.293431.3947497929372138600.stgit@buzzSigned-off-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Roman Gushchin 提交于
[ Upstream commit 4dcabece4c3a9f9522127be12cc12cc120399b2f ] The number of descendant cgroups and the number of dying descendant cgroups are currently synchronized using the cgroup_mutex. The number of descendant cgroups will be required by the cgroup v2 freezer, which will use it to determine if a cgroup is frozen (depending on total number of descendants and number of frozen descendants). It's not always acceptable to grab the cgroup_mutex, especially from quite hot paths (e.g. exit()). To avoid this, let's additionally synchronize these counters using the css_set_lock. So, it's safe to read these counters with either cgroup_mutex or css_set_lock locked, and for changing both locks should be acquired. Signed-off-by: NRoman Gushchin <guro@fb.com> Signed-off-by: NTejun Heo <tj@kernel.org> Cc: kernel-team@fb.com Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Wenwen Wang 提交于
[ Upstream commit 70c4cf17e445264453bc5323db3e50aa0ac9e81f ] In audit_rule_change(), audit_data_to_entry() is firstly invoked to translate the payload data to the kernel's rule representation. In audit_data_to_entry(), depending on the audit field type, an audit tree may be created in audit_make_tree(), which eventually invokes kmalloc() to allocate the tree. Since this tree is a temporary tree, it will be then freed in the following execution, e.g., audit_add_rule() if the message type is AUDIT_ADD_RULE or audit_del_rule() if the message type is AUDIT_DEL_RULE. However, if the message type is neither AUDIT_ADD_RULE nor AUDIT_DEL_RULE, i.e., the default case of the switch statement, this temporary tree is not freed. To fix this issue, only allocate the tree when the type is AUDIT_ADD_RULE or AUDIT_DEL_RULE. Signed-off-by: NWenwen Wang <wang6495@umn.edu> Reviewed-by: NRichard Guy Briggs <rgb@redhat.com> Signed-off-by: NPaul Moore <paul@paul-moore.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Nicholas Piggin 提交于
[ Upstream commit 9b019acb72e4b5741d88e8936d6f200ed44b66b2 ] The NOHZ idle balancer runs on the lowest idle CPU. This can interfere with isolated CPUs, so confine it to HK_FLAG_MISC housekeeping CPUs. HK_FLAG_SCHED is not used for this because it is not set anywhere at the moment. This could be folded into HK_FLAG_SCHED once that option is fixed. The problem was observed with increased jitter on an application running on CPU0, caused by NOHZ idle load balancing being run on CPU1 (an SMT sibling). Signed-off-by: NNicholas Piggin <npiggin@gmail.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190412042613.28930-1-npiggin@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Nadav Amit 提交于
[ Upstream commit f2c65fb3221adc6b73b0549fc7ba892022db9797 ] When modules and BPF filters are loaded, there is a time window in which some memory is both writable and executable. An attacker that has already found another vulnerability (e.g., a dangling pointer) might be able to exploit this behavior to overwrite kernel code. Prevent having writable executable PTEs in this stage. In addition, avoiding having W+X mappings can also slightly simplify the patching of modules code on initialization (e.g., by alternatives and static-key), as would be done in the next patch. This was actually the main motivation for this patch. To avoid having W+X mappings, set them initially as RW (NX) and after they are set as RO set them as X as well. Setting them as executable is done as a separate step to avoid one core in which the old PTE is cached (hence writable), and another which sees the updated PTE (executable), which would break the W^X protection. Suggested-by: NThomas Gleixner <tglx@linutronix.de> Suggested-by: NAndy Lutomirski <luto@amacapital.net> Signed-off-by: NNadav Amit <namit@vmware.com> Signed-off-by: NRick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: https://lkml.kernel.org/r/20190426001143.4983-12-namit@vmware.comSigned-off-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Al Viro 提交于
commit 9419a3191dcb27f24478d288abaab697228d28e6 upstream. What happens there is that we are replacing file->path.mnt of a file we'd just opened with a clone and we need the write count contribution to be transferred from original mount to new one. That's it. We do *NOT* want any kind of freeze protection for the duration of switchover. IOW, we should just use __mnt_{want,drop}_write() for that switchover; no need to bother with mnt_{want,drop}_write() there. Tested-by: NAmir Goldstein <amir73il@gmail.com> Reported-by: syzbot+2a73a6ea9507b7112141@syzkaller.appspotmail.com Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Eric Dumazet 提交于
commit 2baae3545327632167c0180e9ca1d467416f1919 upstream. synchronize_rcu() is fine when the rcu callbacks only need to free memory (kfree_rcu() or direct kfree() call rcu call backs) __dev_map_entry_free() is a bit more complex, so we need to make sure that call queued __dev_map_entry_free() callbacks have completed. sysbot report: BUG: KASAN: use-after-free in dev_map_flush_old kernel/bpf/devmap.c:365 [inline] BUG: KASAN: use-after-free in __dev_map_entry_free+0x2a8/0x300 kernel/bpf/devmap.c:379 Read of size 8 at addr ffff8801b8da38c8 by task ksoftirqd/1/18 CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.17.0+ #39 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 dev_map_flush_old kernel/bpf/devmap.c:365 [inline] __dev_map_entry_free+0x2a8/0x300 kernel/bpf/devmap.c:379 __rcu_reclaim kernel/rcu/rcu.h:178 [inline] rcu_do_batch kernel/rcu/tree.c:2558 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2818 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2785 [inline] rcu_process_callbacks+0xe9d/0x1760 kernel/rcu/tree.c:2802 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:284 run_ksoftirqd+0x86/0x100 kernel/softirq.c:645 smpboot_thread_fn+0x417/0x870 kernel/smpboot.c:164 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Allocated by task 6675: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620 kmalloc include/linux/slab.h:513 [inline] kzalloc include/linux/slab.h:706 [inline] dev_map_alloc+0x208/0x7f0 kernel/bpf/devmap.c:102 find_and_alloc_map kernel/bpf/syscall.c:129 [inline] map_create+0x393/0x1010 kernel/bpf/syscall.c:453 __do_sys_bpf kernel/bpf/syscall.c:2351 [inline] __se_sys_bpf kernel/bpf/syscall.c:2328 [inline] __x64_sys_bpf+0x303/0x510 kernel/bpf/syscall.c:2328 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 26: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xd9/0x260 mm/slab.c:3813 dev_map_free+0x4fa/0x670 kernel/bpf/devmap.c:191 bpf_map_free_deferred+0xba/0xf0 kernel/bpf/syscall.c:262 process_one_work+0xc64/0x1b70 kernel/workqueue.c:2153 worker_thread+0x181/0x13a0 kernel/workqueue.c:2296 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 The buggy address belongs to the object at ffff8801b8da37c0 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 264 bytes inside of 512-byte region [ffff8801b8da37c0, ffff8801b8da39c0) The buggy address belongs to the page: page:ffffea0006e368c0 count:1 mapcount:0 mapping:ffff8801da800940 index:0xffff8801b8da3540 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea0007217b88 ffffea0006e30cc8 ffff8801da800940 raw: ffff8801b8da3540 ffff8801b8da3040 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b8da3780: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801b8da3800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801b8da3880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801b8da3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b8da3980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc Fixes: 546ac1ff ("bpf: add devmap, a map for storing net device references") Signed-off-by: NEric Dumazet <edumazet@google.com> Reported-by: syzbot+457d3e2ffbcf31aee5c0@syzkaller.appspotmail.com Acked-by: NToke Høiland-Jørgensen <toke@redhat.com> Acked-by: NJesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Daniel Borkmann 提交于
commit ede95a63b5e84ddeea6b0c473b36ab8bfd8c6ce3 upstream. Rick reported that the BPF JIT could potentially fill the entire module space with BPF programs from unprivileged users which would prevent later attempts to load normal kernel modules or privileged BPF programs, for example. If JIT was enabled but unsuccessful to generate the image, then before commit 290af866 ("bpf: introduce BPF_JIT_ALWAYS_ON config") we would always fall back to the BPF interpreter. Nowadays in the case where the CONFIG_BPF_JIT_ALWAYS_ON could be set, then the load will abort with a failure since the BPF interpreter was compiled out. Add a global limit and enforce it for unprivileged users such that in case of BPF interpreter compiled out we fail once the limit has been reached or we fall back to BPF interpreter earlier w/o using module mem if latter was compiled in. In a next step, fair share among unprivileged users can be resolved in particular for the case where we would fail hard once limit is reached. Fixes: 290af866 ("bpf: introduce BPF_JIT_ALWAYS_ON config") Fixes: 0a14842f ("net: filter: Just In Time compiler for x86-64") Co-Developed-by: NRick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Jann Horn <jannh@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: LKML <linux-kernel@vger.kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 26 5月, 2019 5 次提交
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由 Daniel Borkmann 提交于
commit 50b045a8c0ccf44f76640ac3eea8d80ca53979a3 upstream. One of the biggest issues we face right now with picking LRU map over regular hash table is that a map walk out of user space, for example, to just dump the existing entries or to remove certain ones, will completely mess up LRU eviction heuristics and wrong entries such as just created ones will get evicted instead. The reason for this is that we mark an entry as "in use" via bpf_lru_node_set_ref() from system call lookup side as well. Thus upon walk, all entries are being marked, so information of actual least recently used ones are "lost". In case of Cilium where it can be used (besides others) as a BPF based connection tracker, this current behavior causes disruption upon control plane changes that need to walk the map from user space to evict certain entries. Discussion result from bpfconf [0] was that we should simply just remove marking from system call side as no good use case could be found where it's actually needed there. Therefore this patch removes marking for regular LRU and per-CPU flavor. If there ever should be a need in future, the behavior could be selected via map creation flag, but due to mentioned reason we avoid this here. [0] http://vger.kernel.org/bpfconf.html Fixes: 29ba732a ("bpf: Add BPF_MAP_TYPE_LRU_HASH") Fixes: 8f844938 ("bpf: Add BPF_MAP_TYPE_LRU_PERCPU_HASH") Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NMartin KaFai Lau <kafai@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Daniel Borkmann 提交于
commit c6110222c6f49ea68169f353565eb865488a8619 upstream. Add a callback map_lookup_elem_sys_only() that map implementations could use over map_lookup_elem() from system call side in case the map implementation needs to handle the latter differently than from the BPF data path. If map_lookup_elem_sys_only() is set, this will be preferred pick for map lookups out of user space. This hook is used in a follow-up fix for LRU map, but once development window opens, we can convert other map types from map_lookup_elem() (here, the one called upon BPF_MAP_LOOKUP_ELEM cmd is meant) over to use the callback to simplify and clean up the latter. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NMartin KaFai Lau <kafai@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Chenbo Feng 提交于
commit e547ff3f803e779a3898f1f48447b29f43c54085 upstream. For iptable module to load a bpf program from a pinned location, it only retrieve a loaded program and cannot change the program content so requiring a write permission for it might not be necessary. Also when adding or removing an unrelated iptable rule, it might need to flush and reload the xt_bpf related rules as well and triggers the inode permission check. It might be better to remove the write premission check for the inode so we won't need to grant write access to all the processes that flush and restore iptables rules. Signed-off-by: NChenbo Feng <fengc@google.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Tobin C. Harding 提交于
[ Upstream commit 9a4f26cc98d81b67ecc23b890c28e2df324e29f3 ] Currently the error return path from kobject_init_and_add() is not followed by a call to kobject_put() - which means we are leaking the kobject. Fix it by adding a call to kobject_put() in the error path of kobject_init_and_add(). Signed-off-by: NTobin C. Harding <tobin@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tobin C. Harding <tobin@kernel.org> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: http://lkml.kernel.org/r/20190430001144.24890-1-tobin@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Elazar Leibovich 提交于
commit cbe08bcbbe787315c425dde284dcb715cfbf3f39 upstream. When reading only part of the id file, the ppos isn't tracked correctly. This is taken care by simple_read_from_buffer. Reading a single byte, and then the next byte would result EOF. While this seems like not a big deal, this breaks abstractions that reads information from files unbuffered. See for example https://github.com/golang/go/issues/29399 This code was mentioned as problematic in commit cd458ba9 ("tracing: Do not (ab)use trace_seq in event_id_read()") An example C code that show this bug is: #include <stdio.h> #include <stdint.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> int main(int argc, char **argv) { if (argc < 2) return 1; int fd = open(argv[1], O_RDONLY); char c; read(fd, &c, 1); printf("First %c\n", c); read(fd, &c, 1); printf("Second %c\n", c); } Then run with, e.g. sudo ./a.out /sys/kernel/debug/tracing/events/tcp/tcp_set_state/id You'll notice you're getting the first character twice, instead of the first two characters in the id file. Link: http://lkml.kernel.org/r/20181231115837.4932-1-elazar@lightbitslabs.com Cc: Orit Wasserman <orit.was@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: stable@vger.kernel.org Fixes: 23725aee ("ftrace: provide an id file for each event") Signed-off-by: NElazar Leibovich <elazar@lightbitslabs.com> Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 22 5月, 2019 2 次提交
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由 Andrea Arcangeli 提交于
commit c3f3ce049f7d97cc7ec9c01cb51d9ec74e0f37c2 upstream. The task structure is freed while get_mem_cgroup_from_mm() holds rcu_read_lock() and dereferences mm->owner. get_mem_cgroup_from_mm() failing fork() ---- --- task = mm->owner mm->owner = NULL; free(task) if (task) *task; /* use after free */ The fix consists in freeing the task with RCU also in the fork failure case, exactly like it always happens for the regular exit(2) path. That is enough to make the rcu_read_lock hold in get_mem_cgroup_from_mm() (left side above) effective to avoid a use after free when dereferencing the task structure. An alternate possible fix would be to defer the delivery of the userfaultfd contexts to the monitor until after fork() is guaranteed to succeed. Such a change would require more changes because it would create a strict ordering dependency where the uffd methods would need to be called beyond the last potentially failing branch in order to be safe. This solution as opposed only adds the dependency to common code to set mm->owner to NULL and to free the task struct that was pointed by mm->owner with RCU, if fork ends up failing. The userfaultfd methods can still be called anywhere during the fork runtime and the monitor will keep discarding orphaned "mm" coming from failed forks in userland. This race condition couldn't trigger if CONFIG_MEMCG was set =n at build time. [aarcange@redhat.com: improve changelog, reduce #ifdefs per Michal] Link: http://lkml.kernel.org/r/20190429035752.4508-1-aarcange@redhat.com Link: http://lkml.kernel.org/r/20190325225636.11635-2-aarcange@redhat.com Fixes: 893e26e6 ("userfaultfd: non-cooperative: Add fork() event") Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Tested-by: Nzhong jiang <zhongjiang@huawei.com> Reported-by: syzbot+cbb52e396df3e565ab02@syzkaller.appspotmail.com Cc: Oleg Nesterov <oleg@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Peter Xu <peterx@redhat.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: zhong jiang <zhongjiang@huawei.com> Cc: syzbot+cbb52e396df3e565ab02@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Waiman Long 提交于
[ Upstream commit a9e9bcb45b1525ba7aea26ed9441e8632aeeda58 ] During my rwsem testing, it was found that after a down_read(), the reader count may occasionally become 0 or even negative. Consequently, a writer may steal the lock at that time and execute with the reader in parallel thus breaking the mutual exclusion guarantee of the write lock. In other words, both readers and writer can become rwsem owners simultaneously. The current reader wakeup code does it in one pass to clear waiter->task and put them into wake_q before fully incrementing the reader count. Once waiter->task is cleared, the corresponding reader may see it, finish the critical section and do unlock to decrement the count before the count is incremented. This is not a problem if there is only one reader to wake up as the count has been pre-incremented by 1. It is a problem if there are more than one readers to be woken up and writer can steal the lock. The wakeup was actually done in 2 passes before the following v4.9 commit: 70800c3c ("locking/rwsem: Scan the wait_list for readers only once") To fix this problem, the wakeup is now done in two passes again. In the first pass, we collect the readers and count them. The reader count is then fully incremented. In the second pass, the waiter->task is then cleared and they are put into wake_q to be woken up later. Signed-off-by: NWaiman Long <longman@redhat.com> Acked-by: NLinus Torvalds <torvalds@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: huang ying <huang.ying.caritas@gmail.com> Fixes: 70800c3c ("locking/rwsem: Scan the wait_list for readers only once") Link: http://lkml.kernel.org/r/20190428212557.13482-2-longman@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NSasha Levin <sashal@kernel.org>
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- 15 5月, 2019 1 次提交
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由 Josh Poimboeuf 提交于
commit 98af8452945c55652de68536afdde3b520fec429 upstream Keeping track of the number of mitigations for all the CPU speculation bugs has become overwhelming for many users. It's getting more and more complicated to decide which mitigations are needed for a given architecture. Complicating matters is the fact that each arch tends to have its own custom way to mitigate the same vulnerability. Most users fall into a few basic categories: a) they want all mitigations off; b) they want all reasonable mitigations on, with SMT enabled even if it's vulnerable; or c) they want all reasonable mitigations on, with SMT disabled if vulnerable. Define a set of curated, arch-independent options, each of which is an aggregation of existing options: - mitigations=off: Disable all mitigations. - mitigations=auto: [default] Enable all the default mitigations, but leave SMT enabled, even if it's vulnerable. - mitigations=auto,nosmt: Enable all the default mitigations, disabling SMT if needed by a mitigation. Currently, these options are placeholders which don't actually do anything. They will be fleshed out in upcoming patches. Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86) Reviewed-by: NJiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Jon Masters <jcm@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tyler Hicks <tyhicks@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Steven Price <steven.price@arm.com> Cc: Phil Auld <pauld@redhat.com> Link: https://lkml.kernel.org/r/b07a8ef9b7c5055c3a4637c87d07c296d5016fe0.1555085500.git.jpoimboe@redhat.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 10 5月, 2019 2 次提交
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由 Will Deacon 提交于
commit 6b4f4bc9cb22875f97023984a625386f0c7cc1c0 upstream. Some futex() operations, including FUTEX_WAKE_OP, require the kernel to perform an atomic read-modify-write of the futex word via the userspace mapping. These operations are implemented by each architecture in arch_futex_atomic_op_inuser() and futex_atomic_cmpxchg_inatomic(), which are called in atomic context with the relevant hash bucket locks held. Although these routines may return -EFAULT in response to a page fault generated when accessing userspace, they are expected to succeed (i.e. return 0) in all other cases. This poses a problem for architectures that do not provide bounded forward progress guarantees or fairness of contended atomic operations and can lead to starvation in some cases. In these problematic scenarios, we must return back to the core futex code so that we can drop the hash bucket locks and reschedule if necessary, much like we do in the case of a page fault. Allow architectures to return -EAGAIN from their implementations of arch_futex_atomic_op_inuser() and futex_atomic_cmpxchg_inatomic(), which will cause the core futex code to reschedule if necessary and return back to the architecture code later on. Cc: <stable@kernel.org> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: NWill Deacon <will.deacon@arm.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Prasad Sodagudi 提交于
[ Upstream commit 59c39840f5abf4a71e1810a8da71aaccd6c17d26 ] When irq_set_affinity_notifier() replaces the notifier, then the reference count on the old notifier is dropped which causes it to be freed. But nothing ensures that the old notifier is not longer queued in the work list. If it is queued this results in a use after free and possibly in work list corruption. Ensure that the work is canceled before the reference is dropped. Signed-off-by: NPrasad Sodagudi <psodagud@codeaurora.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: marc.zyngier@arm.com Link: https://lkml.kernel.org/r/1553439424-6529-1-git-send-email-psodagud@codeaurora.orgSigned-off-by: NSasha Levin <sashal@kernel.org>
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