Commit Graph

32312 Commits

Author SHA1 Message Date
Song Liu
07c5972951 perf/cgroups: Install cgroup events to correct cpuctx
cgroup events are always installed in the cpuctx. However, when it is not
installed via IPI, list_update_cgroup_event() adds it to cpuctx of current
CPU, which triggers list corruption:

  [] list_add double add: new=ffff888ff7cf0db0, prev=ffff888ff7ce82f0, next=ffff888ff7cf0db0.

To reproduce this, we can simply run:

  # perf stat -e cs -a &
  # perf stat -e cs -G anycgroup

Fix this by installing it to cpuctx that contains event->ctx, and the
proper cgrp_cpuctx_list.

Fixes: db0503e4f6 ("perf/core: Optimize perf_install_in_event()")
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200122195027.2112449-1-songliubraving@fb.com
2020-01-28 21:20:19 +01:00
Song Liu
003461559e perf/core: Fix mlock accounting in perf_mmap()
Decreasing sysctl_perf_event_mlock between two consecutive perf_mmap()s of
a perf ring buffer may lead to an integer underflow in locked memory
accounting. This may lead to the undesired behaviors, such as failures in
BPF map creation.

Address this by adjusting the accounting logic to take into account the
possibility that the amount of already locked memory may exceed the
current limit.

Fixes: c4b7547974 ("perf/core: Make the mlock accounting simple again")
Suggested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lkml.kernel.org/r/20200123181146.2238074-1-songliubraving@fb.com
2020-01-28 21:20:18 +01:00
Linus Torvalds
c677124e63 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "These were the main changes in this cycle:

   - More -rt motivated separation of CONFIG_PREEMPT and
     CONFIG_PREEMPTION.

   - Add more low level scheduling topology sanity checks and warnings
     to filter out nonsensical topologies that break scheduling.

   - Extend uclamp constraints to influence wakeup CPU placement

   - Make the RT scheduler more aware of asymmetric topologies and CPU
     capacities, via uclamp metrics, if CONFIG_UCLAMP_TASK=y

   - Make idle CPU selection more consistent

   - Various fixes, smaller cleanups, updates and enhancements - please
     see the git log for details"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits)
  sched/fair: Define sched_idle_cpu() only for SMP configurations
  sched/topology: Assert non-NUMA topology masks don't (partially) overlap
  idle: fix spelling mistake "iterrupts" -> "interrupts"
  sched/fair: Remove redundant call to cpufreq_update_util()
  sched/psi: create /proc/pressure and /proc/pressure/{io|memory|cpu} only when psi enabled
  sched/fair: Fix sgc->{min,max}_capacity calculation for SD_OVERLAP
  sched/fair: calculate delta runnable load only when it's needed
  sched/cputime: move rq parameter in irqtime_account_process_tick
  stop_machine: Make stop_cpus() static
  sched/debug: Reset watchdog on all CPUs while processing sysrq-t
  sched/core: Fix size of rq::uclamp initialization
  sched/uclamp: Fix a bug in propagating uclamp value in new cgroups
  sched/fair: Load balance aggressively for SCHED_IDLE CPUs
  sched/fair : Improve update_sd_pick_busiest for spare capacity case
  watchdog: Remove soft_lockup_hrtimer_cnt and related code
  sched/rt: Make RT capacity-aware
  sched/fair: Make EAS wakeup placement consider uclamp restrictions
  sched/fair: Make task_fits_capacity() consider uclamp restrictions
  sched/uclamp: Rename uclamp_util_with() into uclamp_rq_util_with()
  sched/uclamp: Make uclamp util helpers use and return UL values
  ...
2020-01-28 10:07:09 -08:00
Linus Torvalds
c0e809e244 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
 "Kernel side changes:

   - Ftrace is one of the last W^X violators (after this only KLP is
     left). These patches move it over to the generic text_poke()
     interface and thereby get rid of this oddity. This requires a
     surprising amount of surgery, by Peter Zijlstra.

   - x86/AMD PMUs: add support for 'Large Increment per Cycle Events' to
     count certain types of events that have a special, quirky hw ABI
     (by Kim Phillips)

   - kprobes fixes by Masami Hiramatsu

  Lots of tooling updates as well, the following subcommands were
  updated: annotate/report/top, c2c, clang, record, report/top TUI,
  sched timehist, tests; plus updates were done to the gtk ui, libperf,
  headers and the parser"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
  perf/x86/amd: Add support for Large Increment per Cycle Events
  perf/x86/amd: Constrain Large Increment per Cycle events
  perf/x86/intel/rapl: Add Comet Lake support
  tracing: Initialize ret in syscall_enter_define_fields()
  perf header: Use last modification time for timestamp
  perf c2c: Fix return type for histogram sorting comparision functions
  perf beauty sockaddr: Fix augmented syscall format warning
  perf/ui/gtk: Fix gtk2 build
  perf ui gtk: Add missing zalloc object
  perf tools: Use %define api.pure full instead of %pure-parser
  libperf: Setup initial evlist::all_cpus value
  perf report: Fix no libunwind compiled warning break s390 issue
  perf tools: Support --prefix/--prefix-strip
  perf report: Clarify in help that --children is default
  tools build: Fix test-clang.cpp with Clang 8+
  perf clang: Fix build with Clang 9
  kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logic
  tools lib: Fix builds when glibc contains strlcpy()
  perf report/top: Make 'e' visible in the help and make it toggle showing callchains
  perf report/top: Do not offer annotation for symbols without samples
  ...
2020-01-28 09:44:15 -08:00
Linus Torvalds
2180f214f4 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
 "Just a handful of changes in this cycle: an ARM64 performance
  optimization, a comment fix and a debug output fix"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/osq: Use optimized spinning loop for arm64
  locking/qspinlock: Fix inaccessible URL of MCS lock paper
  locking/lockdep: Fix lockdep_stats indentation problem
2020-01-28 09:33:25 -08:00
Linus Torvalds
d99391ec2b Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The RCU changes in this cycle were:
   - Expedited grace-period updates
   - kfree_rcu() updates
   - RCU list updates
   - Preemptible RCU updates
   - Torture-test updates
   - Miscellaneous fixes
   - Documentation updates"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (69 commits)
  rcu: Remove unused stop-machine #include
  powerpc: Remove comment about read_barrier_depends()
  .mailmap: Add entries for old paulmck@kernel.org addresses
  srcu: Apply *_ONCE() to ->srcu_last_gp_end
  rcu: Switch force_qs_rnp() to for_each_leaf_node_cpu_mask()
  rcu: Move rcu_{expedited,normal} definitions into rcupdate.h
  rcu: Move gp_state_names[] and gp_state_getname() to tree_stall.h
  rcu: Remove the declaration of call_rcu() in tree.h
  rcu: Fix tracepoint tracking RCU CPU kthread utilization
  rcu: Fix harmless omission of "CONFIG_" from #if condition
  rcu: Avoid tick_dep_set_cpu() misordering
  rcu: Provide wrappers for uses of ->rcu_read_lock_nesting
  rcu: Use READ_ONCE() for ->expmask in rcu_read_unlock_special()
  rcu: Clear ->rcu_read_unlock_special only once
  rcu: Clear .exp_hint only when deferred quiescent state has been reported
  rcu: Rename some instance of CONFIG_PREEMPTION to CONFIG_PREEMPT_RCU
  rcu: Remove kfree_call_rcu_nobatch()
  rcu: Remove kfree_rcu() special casing and lazy-callback handling
  rcu: Add support for debug_objects debugging for kfree_rcu()
  rcu: Add multiple in-flight batches of kfree_rcu() work
  ...
2020-01-28 08:46:13 -08:00
Sebastian Andrzej Siewior
25a3a15417 smp: Remove superfluous cond_func check in smp_call_function_many_cond()
It was requested to remove the cond_func check but the follow up patch was
overlooked. Remove it now.

Fixes: 67719ef25e ("smp: Add a smp_cond_func_t argument to smp_call_function_many()")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200127083915.434tdkztorkklpdu@linutronix.de
2020-01-28 15:43:00 +01:00
Mike Christie
8d19f1c8e1
prctl: PR_{G,S}ET_IO_FLUSHER to support controlling memory reclaim
There are several storage drivers like dm-multipath, iscsi, tcmu-runner,
amd nbd that have userspace components that can run in the IO path. For
example, iscsi and nbd's userspace deamons may need to recreate a socket
and/or send IO on it, and dm-multipath's daemon multipathd may need to
send SG IO or read/write IO to figure out the state of paths and re-set
them up.

In the kernel these drivers have access to GFP_NOIO/GFP_NOFS and the
memalloc_*_save/restore functions to control the allocation behavior,
but for userspace we would end up hitting an allocation that ended up
writing data back to the same device we are trying to allocate for.
The device is then in a state of deadlock, because to execute IO the
device needs to allocate memory, but to allocate memory the memory
layers want execute IO to the device.

Here is an example with nbd using a local userspace daemon that performs
network IO to a remote server. We are using XFS on top of the nbd device,
but it can happen with any FS or other modules layered on top of the nbd
device that can write out data to free memory.  Here a nbd daemon helper
thread, msgr-worker-1, is performing a write/sendmsg on a socket to execute
a request. This kicks off a reclaim operation which results in a WRITE to
the nbd device and the nbd thread calling back into the mm layer.

[ 1626.609191] msgr-worker-1   D    0  1026      1 0x00004000
[ 1626.609193] Call Trace:
[ 1626.609195]  ? __schedule+0x29b/0x630
[ 1626.609197]  ? wait_for_completion+0xe0/0x170
[ 1626.609198]  schedule+0x30/0xb0
[ 1626.609200]  schedule_timeout+0x1f6/0x2f0
[ 1626.609202]  ? blk_finish_plug+0x21/0x2e
[ 1626.609204]  ? _xfs_buf_ioapply+0x2e6/0x410
[ 1626.609206]  ? wait_for_completion+0xe0/0x170
[ 1626.609208]  wait_for_completion+0x108/0x170
[ 1626.609210]  ? wake_up_q+0x70/0x70
[ 1626.609212]  ? __xfs_buf_submit+0x12e/0x250
[ 1626.609214]  ? xfs_bwrite+0x25/0x60
[ 1626.609215]  xfs_buf_iowait+0x22/0xf0
[ 1626.609218]  __xfs_buf_submit+0x12e/0x250
[ 1626.609220]  xfs_bwrite+0x25/0x60
[ 1626.609222]  xfs_reclaim_inode+0x2e8/0x310
[ 1626.609224]  xfs_reclaim_inodes_ag+0x1b6/0x300
[ 1626.609227]  xfs_reclaim_inodes_nr+0x31/0x40
[ 1626.609228]  super_cache_scan+0x152/0x1a0
[ 1626.609231]  do_shrink_slab+0x12c/0x2d0
[ 1626.609233]  shrink_slab+0x9c/0x2a0
[ 1626.609235]  shrink_node+0xd7/0x470
[ 1626.609237]  do_try_to_free_pages+0xbf/0x380
[ 1626.609240]  try_to_free_pages+0xd9/0x1f0
[ 1626.609245]  __alloc_pages_slowpath+0x3a4/0xd30
[ 1626.609251]  ? ___slab_alloc+0x238/0x560
[ 1626.609254]  __alloc_pages_nodemask+0x30c/0x350
[ 1626.609259]  skb_page_frag_refill+0x97/0xd0
[ 1626.609274]  sk_page_frag_refill+0x1d/0x80
[ 1626.609279]  tcp_sendmsg_locked+0x2bb/0xdd0
[ 1626.609304]  tcp_sendmsg+0x27/0x40
[ 1626.609307]  sock_sendmsg+0x54/0x60
[ 1626.609308]  ___sys_sendmsg+0x29f/0x320
[ 1626.609313]  ? sock_poll+0x66/0xb0
[ 1626.609318]  ? ep_item_poll.isra.15+0x40/0xc0
[ 1626.609320]  ? ep_send_events_proc+0xe6/0x230
[ 1626.609322]  ? hrtimer_try_to_cancel+0x54/0xf0
[ 1626.609324]  ? ep_read_events_proc+0xc0/0xc0
[ 1626.609326]  ? _raw_write_unlock_irq+0xa/0x20
[ 1626.609327]  ? ep_scan_ready_list.constprop.19+0x218/0x230
[ 1626.609329]  ? __hrtimer_init+0xb0/0xb0
[ 1626.609331]  ? _raw_spin_unlock_irq+0xa/0x20
[ 1626.609334]  ? ep_poll+0x26c/0x4a0
[ 1626.609337]  ? tcp_tsq_write.part.54+0xa0/0xa0
[ 1626.609339]  ? release_sock+0x43/0x90
[ 1626.609341]  ? _raw_spin_unlock_bh+0xa/0x20
[ 1626.609342]  __sys_sendmsg+0x47/0x80
[ 1626.609347]  do_syscall_64+0x5f/0x1c0
[ 1626.609349]  ? prepare_exit_to_usermode+0x75/0xa0
[ 1626.609351]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

This patch adds a new prctl command that daemons can use after they have
done their initial setup, and before they start to do allocations that
are in the IO path. It sets the PF_MEMALLOC_NOIO and PF_LESS_THROTTLE
flags so both userspace block and FS threads can use it to avoid the
allocation recursion and try to prevent from being throttled while
writing out data to free up memory.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Masato Suzuki <masato.suzuki@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Link: https://lore.kernel.org/r/20191112001900.9206-1-mchristi@redhat.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-01-28 10:09:51 +01:00
Ingo Molnar
0cc4bd8f70 Merge branch 'core/kprobes' into perf/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-28 07:59:05 +01:00
Linus Torvalds
3d3b44a61a The interrupt departement provides:
- A mechanism to shield isolated tasks from managed interrupts:
 
    The affinity of managed interrupts is completely controlled by the
    kernel and user space has no influence on them. The reason is that
    the automatically assigned affinity correlates to the multi-queue
    CPU handling of block devices.
 
    If the generated affinity mask spaws both housekeeping and isolated CPUs
    the interrupt could be routed to an isolated CPU which would then be
    disturbed by I/O submitted by a housekeeping CPU.
 
    The new mechamism ensures that as long as one housekeeping CPU is online
    in the assigned affinity mask the interrupt is routed to a housekeeping
    CPU.
 
    If there is no online housekeeping CPU in the affinity mask, then the
    interrupt is routed to an isolated CPU to keep the device queue intact,
    but unless the isolated CPU submits I/O by itself these interrupts are
    not raised.
 
  - A small addon to the device tree irqdomain core code to avoid
    duplication in irq chip drivers
 
  - Conversion of the SiFive PLIC to hierarchical domains
 
  - The usual pile of new irq chip drivers: SiFive GPIO, Aspeed SCI, NXP
    INTMUX, Meson A1 GPIO
 
  - The first cut of support for the new ARM GICv4.1
 
  - The usual pile of fixes and improvements in core and driver code
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Merge tag 'irq-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "The interrupt departement provides:

   - A mechanism to shield isolated tasks from managed interrupts:

     The affinity of managed interrupts is completely controlled by the
     kernel and user space has no influence on them. The reason is that
     the automatically assigned affinity correlates to the multi-queue
     CPU handling of block devices.

     If the generated affinity mask spaws both housekeeping and isolated
     CPUs the interrupt could be routed to an isolated CPU which would
     then be disturbed by I/O submitted by a housekeeping CPU.

     The new mechamism ensures that as long as one housekeeping CPU is
     online in the assigned affinity mask the interrupt is routed to a
     housekeeping CPU.

     If there is no online housekeeping CPU in the affinity mask, then
     the interrupt is routed to an isolated CPU to keep the device queue
     intact, but unless the isolated CPU submits I/O by itself these
     interrupts are not raised.

   - A small addon to the device tree irqdomain core code to avoid
     duplication in irq chip drivers

   - Conversion of the SiFive PLIC to hierarchical domains

   - The usual pile of new irq chip drivers: SiFive GPIO, Aspeed SCI,
     NXP INTMUX, Meson A1 GPIO

   - The first cut of support for the new ARM GICv4.1

   - The usual pile of fixes and improvements in core and driver code"

* tag 'irq-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  genirq, sched/isolation: Isolate from handling managed interrupts
  irqchip/gic-v4.1: Allow direct invalidation of VLPIs
  irqchip/gic-v4.1: Suppress per-VLPI doorbell
  irqchip/gic-v4.1: Add VPE INVALL callback
  irqchip/gic-v4.1: Add VPE eviction callback
  irqchip/gic-v4.1: Add VPE residency callback
  irqchip/gic-v4.1: Add mask/unmask doorbell callbacks
  irqchip/gic-v4.1: Plumb skeletal VPE irqchip
  irqchip/gic-v4.1: Implement the v4.1 flavour of VMOVP
  irqchip/gic-v4.1: Don't use the VPE proxy if RVPEID is set
  irqchip/gic-v4.1: Implement the v4.1 flavour of VMAPP
  irqchip/gic-v4.1: VPE table (aka GICR_VPROPBASER) allocation
  irqchip/gic-v3: Add GICv4.1 VPEID size discovery
  irqchip/gic-v3: Detect GICv4.1 supporting RVPEID
  irqchip/gic-v3-its: Fix get_vlpi_map() breakage with doorbells
  irqdomain: Fix a memory leak in irq_domain_push_irq()
  irqchip: Add NXP INTMUX interrupt multiplexer support
  dt-bindings: interrupt-controller: Add binding for NXP INTMUX interrupt multiplexer
  irqchip: Define EXYNOS_IRQ_COMBINER
  irqchip/meson-gpio: Add support for meson a1 SoCs
  ...
2020-01-27 17:22:21 -08:00
Linus Torvalds
ab67f60025 A small set of SMP core code changes:
- Rework the smp function call core code to avoid the allocation of an
    additional cpumask.
 
  - Remove the not longer required GFP argument from on_each_cpu_cond() and
    on_each_cpu_cond_mask() and fixup the callers.
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Merge tag 'smp-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core SMP updates from Thomas Gleixner:
 "A small set of SMP core code changes:

   - Rework the smp function call core code to avoid the allocation of
     an additional cpumask

   - Remove the not longer required GFP argument from on_each_cpu_cond()
     and on_each_cpu_cond_mask() and fixup the callers"

* tag 'smp-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp: Remove allocation mask from on_each_cpu_cond.*()
  smp: Add a smp_cond_func_t argument to smp_call_function_many()
  smp: Use smp_cond_func_t as type for the conditional function
2020-01-27 17:04:51 -08:00
Linus Torvalds
e279160f49 The timekeeping and timers departement provides:
- Time namespace support:
 
     If a container migrates from one host to another then it expects that
     clocks based on MONOTONIC and BOOTTIME are not subject to
     disruption. Due to different boot time and non-suspended runtime these
     clocks can differ significantly on two hosts, in the worst case time
     goes backwards which is a violation of the POSIX requirements.
 
     The time namespace addresses this problem. It allows to set offsets for
     clock MONOTONIC and BOOTTIME once after creation and before tasks are
     associated with the namespace. These offsets are taken into account by
     timers and timekeeping including the VDSO.
 
     Offsets for wall clock based clocks (REALTIME/TAI) are not provided by
     this mechanism. While in theory possible, the overhead and code
     complexity would be immense and not justified by the esoteric potential
     use cases which were discussed at Plumbers '18.
 
     The overhead for tasks in the root namespace (host time offsets = 0) is
     in the noise and great effort was made to ensure that especially in the
     VDSO. If time namespace is disabled in the kernel configuration the
     code is compiled out.
 
     Kudos to Andrei Vagin and Dmitry Sofanov who implemented this feature
     and kept on for more than a year addressing review comments, finding
     better solutions. A pleasant experience.
 
   - Overhaul of the alarmtimer device dependency handling to ensure that
     the init/suspend/resume ordering is correct.
 
   - A new clocksource/event driver for Microchip PIT64
 
   - Suspend/resume support for the Hyper-V clocksource
 
   - The usual pile of fixes, updates and improvements mostly in the
     driver code.
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Merge tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "The timekeeping and timers departement provides:

   - Time namespace support:

     If a container migrates from one host to another then it expects
     that clocks based on MONOTONIC and BOOTTIME are not subject to
     disruption. Due to different boot time and non-suspended runtime
     these clocks can differ significantly on two hosts, in the worst
     case time goes backwards which is a violation of the POSIX
     requirements.

     The time namespace addresses this problem. It allows to set offsets
     for clock MONOTONIC and BOOTTIME once after creation and before
     tasks are associated with the namespace. These offsets are taken
     into account by timers and timekeeping including the VDSO.

     Offsets for wall clock based clocks (REALTIME/TAI) are not provided
     by this mechanism. While in theory possible, the overhead and code
     complexity would be immense and not justified by the esoteric
     potential use cases which were discussed at Plumbers '18.

     The overhead for tasks in the root namespace (ie where host time
     offsets = 0) is in the noise and great effort was made to ensure
     that especially in the VDSO. If time namespace is disabled in the
     kernel configuration the code is compiled out.

     Kudos to Andrei Vagin and Dmitry Sofanov who implemented this
     feature and kept on for more than a year addressing review
     comments, finding better solutions. A pleasant experience.

   - Overhaul of the alarmtimer device dependency handling to ensure
     that the init/suspend/resume ordering is correct.

   - A new clocksource/event driver for Microchip PIT64

   - Suspend/resume support for the Hyper-V clocksource

   - The usual pile of fixes, updates and improvements mostly in the
     driver code"

* tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  alarmtimer: Make alarmtimer_get_rtcdev() a stub when CONFIG_RTC_CLASS=n
  alarmtimer: Use wakeup source from alarmtimer platform device
  alarmtimer: Make alarmtimer platform device child of RTC device
  alarmtimer: Update alarmtimer_get_rtcdev() docs to reflect reality
  hrtimer: Add missing sparse annotation for __run_timer()
  lib/vdso: Only read hrtimer_res when needed in __cvdso_clock_getres()
  MIPS: vdso: Define BUILD_VDSO32 when building a 32bit kernel
  clocksource/drivers/hyper-v: Set TSC clocksource as default w/ InvariantTSC
  clocksource/drivers/hyper-v: Untangle stimers and timesync from clocksources
  clocksource/drivers/timer-microchip-pit64b: Fix sparse warning
  clocksource/drivers/exynos_mct: Rename Exynos to lowercase
  clocksource/drivers/timer-ti-dm: Fix uninitialized pointer access
  clocksource/drivers/timer-ti-dm: Switch to platform_get_irq
  clocksource/drivers/timer-ti-dm: Convert to devm_platform_ioremap_resource
  clocksource/drivers/em_sti: Fix variable declaration in em_sti_probe
  clocksource/drivers/em_sti: Convert to devm_platform_ioremap_resource
  clocksource/drivers/bcm2835_timer: Fix memory leak of timer
  clocksource/drivers/cadence-ttc: Use ttc driver as platform driver
  clocksource/drivers/timer-microchip-pit64b: Add Microchip PIT64B support
  clocksource/drivers/hyper-v: Reserve PAGE_SIZE space for tsc page
  ...
2020-01-27 16:47:05 -08:00
Linus Torvalds
b11c89a158 A set of watchdog/softlockup related improvements:
- Enforce that the watchdog timestamp is always valid on boot. The
    original implementation caused a watchdog disabled gap of one second in
    the boot process due to truncation of the underlying sched clock. The
    sched clock is divided by 1e9 to convert nanoseconds to seconds. So for
    the first second of the boot process the result is 0 which is at the
    same time the indicator to disable the watchdog. The trivial fix is to
    change the disabled indicator to ULONG_MAX.
 
  - Two cleanup patches removing unused and redundant code which got
    forgotten to be cleaned up in previous changes.
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Merge tag 'core-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull watchdog updates from Thomas Gleixner:
 "A set of watchdog/softlockup related improvements:

   - Enforce that the watchdog timestamp is always valid on boot. The
     original implementation caused a watchdog disabled gap of one
     second in the boot process due to truncation of the underlying
     sched clock.

     The sched clock is divided by 1e9 to convert nanoseconds to
     seconds. So for the first second of the boot process the result is
     0 which is at the same time the indicator to disable the watchdog.

     The trivial fix is to change the disabled indicator to ULONG_MAX.

   - Two cleanup patches removing unused and redundant code which got
     forgotten to be cleaned up in previous changes"

* tag 'core-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  watchdog/softlockup: Enforce that timestamp is valid on boot
  watchdog/softlockup: Remove obsolete check of last reported task
  watchdog: Remove soft_lockup_hrtimer_cnt and related code
2020-01-27 16:42:11 -08:00
Linus Torvalds
a56c41e5d7 Two fixes for the generic VDSO code which missed 5.5:
- Make the update to the coarse timekeeper unconditional. This is required
    because the coarse timekeeper interfaces in the VDSO do not depend on a
    VDSO capable clocksource. If the system does not have a VDSO capable
    clocksource and the update is depending on the VDSO capable clocksource,
    the coarse VDSO interfaces would operate on stale data forever.
 
  - Invert the logic of __arch_update_vdso_data() to avoid further head
    scratching. Tripped over this several times while analyzing the update
    problem above.
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Merge tag 'timers-urgent-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:
 "Two fixes for the generic VDSO code which missed 5.5:

   - Make the update to the coarse timekeeper unconditional.

     This is required because the coarse timekeeper interfaces in the
     VDSO do not depend on a VDSO capable clocksource. If the system
     does not have a VDSO capable clocksource and the update is
     depending on the VDSO capable clocksource, the coarse VDSO
     interfaces would operate on stale data forever.

   - Invert the logic of __arch_update_vdso_data() to avoid further head
     scratching.

     Tripped over this several times while analyzing the update problem
     above"

* tag 'timers-urgent-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lib/vdso: Update coarse timekeeper unconditionally
  lib/vdso: Make __arch_update_vdso_data() logic understandable
2020-01-27 16:37:40 -08:00
Linus Torvalds
07e309a972 audit/stable-5.6 PR 20200127
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Merge tag 'audit-pr-20200127' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

Pull audit update from Paul Moore:
 "One small audit patch for the Linux v5.6 merge window, and
  unsurprisingly it passes our test suite with flying colors"

* tag 'audit-pr-20200127' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: Add __rcu annotation to RCU pointer
2020-01-27 15:35:50 -08:00
Linus Torvalds
03aa8c8cfa Merge branch 'for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:

 - cgroup2 interface for hugetlb controller. I think this was the last
   remaining bit which was missing from cgroup2

 - fixes for race and a spurious warning in threaded cgroup handling

 - other minor changes

* 'for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  iocost: Fix iocost_monitor.py due to helper type mismatch
  cgroup: Prevent double killing of css when enabling threaded cgroup
  cgroup: fix function name in comment
  mm: hugetlb controller for cgroups v2
2020-01-27 15:18:25 -08:00
Linus Torvalds
16d06120d7 Merge branch 'for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo:
 "Just a couple tracepoint patches"

* 'for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: remove workqueue_work event class
  workqueue: add worker function to workqueue_execute_end tracepoint
2020-01-27 15:16:52 -08:00
Linus Torvalds
6d277aca48 Power management updates for 5.6-rc1
- Update the ACPI processor driver in order to export
    acpi_processor_evaluate_cst() to the code outside of it, add
    ACPI support to the intel_idle driver based on that and clean
    up that driver somewhat (Rafael Wysocki).
 
  - Add an admin guide document for the intel_idle driver (Rafael
    Wysocki).
 
  - Clean up cpuidle core and drivers, enable compilation testing
    for some of them (Benjamin Gaignard, Krzysztof Kozlowski, Rafael
    Wysocki, Yangtao Li).
 
  - Fix reference counting of OPP (operating performance points) table
    structures (Viresh Kumar).
 
  - Add support for CPR (Core Power Reduction) to the AVS (Adaptive
    Voltage Scaling) subsystem (Niklas Cassel, Colin Ian King,
    YueHaibing).
 
  - Add support for TigerLake Mobile and JasperLake to the Intel RAPL
    power capping driver (Zhang Rui).
 
  - Update cpufreq drivers:
 
    * Add i.MX8MP support to imx-cpufreq-dt (Anson Huang).
 
    * Fix usage of a macro in loongson2_cpufreq (Alexandre Oliva).
 
    * Fix cpufreq policy reference counting issues in s3c and
      brcmstb-avs (chenqiwu).
 
    * Fix ACPI table reference counting issue and HiSilicon quirk
      handling in the CPPC driver (Hanjun Guo).
 
    * Clean up spelling mistake in intel_pstate (Harry Pan).
 
    * Convert the kirkwood and tegra186 drivers to using
      devm_platform_ioremap_resource() (Yangtao Li).
 
  - Update devfreq core:
 
    * Add 'name' sysfs attribute for devfreq devices (Chanwoo Choi).
 
    * Clean up the handing of transition statistics and allow them
      to be reset by writing 0 to the 'trans_stat' devfreq device
      attribute in sysfs (Kamil Konieczny).
 
    * Add 'devfreq_summary' to debugfs (Chanwoo Choi).
 
    * Clean up kerneldoc comments and Kconfig indentation (Krzysztof
      Kozlowski, Randy Dunlap).
 
  - Update devfreq drivers:
 
    * Add dynamic scaling for the imx8m DDR controller and clean up
      imx8m-ddrc (Leonard Crestez, YueHaibing).
 
    * Fix DT node reference counting and nitialization error code path
      in rk3399_dmc and add COMPILE_TEST and HAVE_ARM_SMCCC dependency
      for it (Chanwoo Choi, Yangtao Li).
 
    * Fix DT node reference counting in rockchip-dfi and make it use
      devm_platform_ioremap_resource() (Yangtao Li).
 
    * Fix excessive stack usage in exynos-ppmu (Arnd Bergmann).
 
    * Fix initialization error code paths in exynos-bus (Yangtao Li).
 
    * Clean up exynos-bus and exynos somewhat (Artur Świgoń, Krzysztof
      Kozlowski).
 
  - Add tracepoints for tracking usage_count updates unrelated to
    status changes in PM-runtime (Michał Mirosław).
 
  - Add sysfs attribute to control the "sync on suspend" behavior
    during system-wide suspend (Jonas Meurer).
 
  - Switch system-wide suspend tests over to 64-bit time (Alexandre
    Belloni).
 
  - Make wakeup sources statistics in debugfs cover deleted ones which
    used to be the case some time ago (zhuguangqing).
 
  - Clean up computations carried out during hibernation, update
    messages related to hibernation and fix a spelling mistake in one
    of them (Wen Yang, Luigi Semenzato, Colin Ian King).
 
  - Add mailmap entry for maintainer e-mail address that has not been
    functional for several years (Rafael Wysocki).
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Merge tag 'pm-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "These add ACPI support to the intel_idle driver along with an admin
  guide document for it, add support for CPR (Core Power Reduction) to
  the AVS (Adaptive Voltage Scaling) subsystem, add new hardware support
  in a few places, add some new sysfs attributes, debugfs files and
  tracepoints, fix bugs and clean up a bunch of things all over.

  Specifics:

   - Update the ACPI processor driver in order to export
     acpi_processor_evaluate_cst() to the code outside of it, add ACPI
     support to the intel_idle driver based on that and clean up that
     driver somewhat (Rafael Wysocki).

   - Add an admin guide document for the intel_idle driver (Rafael
     Wysocki).

   - Clean up cpuidle core and drivers, enable compilation testing for
     some of them (Benjamin Gaignard, Krzysztof Kozlowski, Rafael
     Wysocki, Yangtao Li).

   - Fix reference counting of OPP (operating performance points) table
     structures (Viresh Kumar).

   - Add support for CPR (Core Power Reduction) to the AVS (Adaptive
     Voltage Scaling) subsystem (Niklas Cassel, Colin Ian King,
     YueHaibing).

   - Add support for TigerLake Mobile and JasperLake to the Intel RAPL
     power capping driver (Zhang Rui).

   - Update cpufreq drivers:
      - Add i.MX8MP support to imx-cpufreq-dt (Anson Huang).
      - Fix usage of a macro in loongson2_cpufreq (Alexandre Oliva).
      - Fix cpufreq policy reference counting issues in s3c and
        brcmstb-avs (chenqiwu).
      - Fix ACPI table reference counting issue and HiSilicon quirk
        handling in the CPPC driver (Hanjun Guo).
      - Clean up spelling mistake in intel_pstate (Harry Pan).
      - Convert the kirkwood and tegra186 drivers to using
        devm_platform_ioremap_resource() (Yangtao Li).

   - Update devfreq core:
      - Add 'name' sysfs attribute for devfreq devices (Chanwoo Choi).
      - Clean up the handing of transition statistics and allow them to
        be reset by writing 0 to the 'trans_stat' devfreq device
        attribute in sysfs (Kamil Konieczny).
      - Add 'devfreq_summary' to debugfs (Chanwoo Choi).
      - Clean up kerneldoc comments and Kconfig indentation (Krzysztof
        Kozlowski, Randy Dunlap).

   - Update devfreq drivers:
      - Add dynamic scaling for the imx8m DDR controller and clean up
        imx8m-ddrc (Leonard Crestez, YueHaibing).
      - Fix DT node reference counting and nitialization error code path
        in rk3399_dmc and add COMPILE_TEST and HAVE_ARM_SMCCC dependency
        for it (Chanwoo Choi, Yangtao Li).
      - Fix DT node reference counting in rockchip-dfi and make it use
        devm_platform_ioremap_resource() (Yangtao Li).
      - Fix excessive stack usage in exynos-ppmu (Arnd Bergmann).
      - Fix initialization error code paths in exynos-bus (Yangtao Li).
      - Clean up exynos-bus and exynos somewhat (Artur Świgoń, Krzysztof
        Kozlowski).

   - Add tracepoints for tracking usage_count updates unrelated to
     status changes in PM-runtime (Michał Mirosław).

   - Add sysfs attribute to control the "sync on suspend" behavior
     during system-wide suspend (Jonas Meurer).

   - Switch system-wide suspend tests over to 64-bit time (Alexandre
     Belloni).

   - Make wakeup sources statistics in debugfs cover deleted ones which
     used to be the case some time ago (zhuguangqing).

   - Clean up computations carried out during hibernation, update
     messages related to hibernation and fix a spelling mistake in one
     of them (Wen Yang, Luigi Semenzato, Colin Ian King).

   - Add mailmap entry for maintainer e-mail address that has not been
     functional for several years (Rafael Wysocki)"

* tag 'pm-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (83 commits)
  cpufreq: loongson2_cpufreq: adjust cpufreq uses of LOONGSON_CHIPCFG
  intel_idle: Clean up irtl_2_usec()
  intel_idle: Move 3 functions closer to their callers
  intel_idle: Annotate initialization code and data structures
  intel_idle: Move and clean up intel_idle_cpuidle_devices_uninit()
  intel_idle: Rearrange intel_idle_cpuidle_driver_init()
  intel_idle: Clean up NULL pointer check in intel_idle_init()
  intel_idle: Fold intel_idle_probe() into intel_idle_init()
  intel_idle: Eliminate __setup_broadcast_timer()
  cpuidle: fix cpuidle_find_deepest_state() kerneldoc warnings
  cpuidle: sysfs: fix warnings when compiling with W=1
  cpuidle: coupled: fix warnings when compiling with W=1
  cpufreq: brcmstb-avs: fix imbalance of cpufreq policy refcount
  PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior
  PM / devfreq: Add debugfs support with devfreq_summary file
  Documentation: admin-guide: PM: Add intel_idle document
  cpuidle: arm: Enable compile testing for some of drivers
  PM-runtime: add tracepoints for usage_count changes
  cpufreq: intel_pstate: fix spelling mistake: "Whethet" -> "Whether"
  PM: hibernate: fix spelling mistake "shapshot" -> "snapshot"
  ...
2020-01-27 11:23:54 -08:00
Linus Torvalds
0238d3c753 arm64 updates for 5.6
- New architecture features
 	* Support for Armv8.5 E0PD, which benefits KASLR in the same way as
 	  KPTI but without the overhead. This allows KPTI to be disabled on
 	  CPUs that are not affected by Meltdown, even is KASLR is enabled.
 
 	* Initial support for the Armv8.5 RNG instructions, which claim to
 	  provide access to a high bandwidth, cryptographically secure hardware
 	  random number generator. As well as exposing these to userspace, we
 	  also use them as part of the KASLR seed and to seed the crng once
 	  all CPUs have come online.
 
 	* Advertise a bunch of new instructions to userspace, including support
 	  for Data Gathering Hint, Matrix Multiply and 16-bit floating point.
 
 - Kexec
 	* Cleanups in preparation for relocating with the MMU enabled
 	* Support for loading crash dump kernels with kexec_file_load()
 
 - Perf and PMU drivers
 	* Cleanups and non-critical fixes for a couple of system PMU drivers
 
 - FPU-less (aka broken) CPU support
 	* Considerable fixes to support CPUs without the FP/SIMD extensions,
 	  including their presence in heterogeneous systems. Good luck finding
 	  a 64-bit userspace that handles this.
 
 - Modern assembly function annotations
 	* Start migrating our use of ENTRY() and ENDPROC() over to the
 	  new-fangled SYM_{CODE,FUNC}_{START,END} macros, which are intended to
 	  aid debuggers
 
 - Kbuild
 	* Cleanup detection of LSE support in the assembler by introducing
 	  'as-instr'
 
 	* Remove compressed Image files when building clean targets
 
 - IP checksumming
 	* Implement optimised IPv4 checksumming routine when hardware offload
 	  is not in use. An IPv6 version is in the works, pending testing.
 
 - Hardware errata
 	* Work around Cortex-A55 erratum #1530923
 
 - Shadow call stack
 	* Work around some issues with Clang's integrated assembler not liking
 	  our perfectly reasonable assembly code
 
 	* Avoid allocating the X18 register, so that it can be used to hold the
 	  shadow call stack pointer in future
 
 - ACPI
 	* Fix ID count checking in IORT code. This may regress broken firmware
 	  that happened to work with the old implementation, in which case we'll
 	  have to revert it and try something else
 
 	* Fix DAIF corruption on return from GHES handler with pseudo-NMIs
 
 - Miscellaneous
 	* Whitelist some CPUs that are unaffected by Spectre-v2
 
 	* Reduce frequency of ASID rollover when KPTI is compiled in but
 	  inactive
 
 	* Reserve a couple of arch-specific PROT flags that are already used by
 	  Sparc and PowerPC and are planned for later use with BTI on arm64
 
 	* Preparatory cleanup of our entry assembly code in preparation for
 	  moving more of it into C later on
 
 	* Refactoring and cleanup
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "The changes are a real mixed bag this time around.

  The only scary looking one from the diffstat is the uapi change to
  asm-generic/mman-common.h, but this has been acked by Arnd and is
  actually just adding a pair of comments in an attempt to prevent
  allocation of some PROT values which tend to get used for
  arch-specific purposes. We'll be using them for Branch Target
  Identification (a CFI-like hardening feature), which is currently
  under review on the mailing list.

  New architecture features:

   - Support for Armv8.5 E0PD, which benefits KASLR in the same way as
     KPTI but without the overhead. This allows KPTI to be disabled on
     CPUs that are not affected by Meltdown, even is KASLR is enabled.

   - Initial support for the Armv8.5 RNG instructions, which claim to
     provide access to a high bandwidth, cryptographically secure
     hardware random number generator. As well as exposing these to
     userspace, we also use them as part of the KASLR seed and to seed
     the crng once all CPUs have come online.

   - Advertise a bunch of new instructions to userspace, including
     support for Data Gathering Hint, Matrix Multiply and 16-bit
     floating point.

  Kexec:

   - Cleanups in preparation for relocating with the MMU enabled

   - Support for loading crash dump kernels with kexec_file_load()

  Perf and PMU drivers:

   - Cleanups and non-critical fixes for a couple of system PMU drivers

  FPU-less (aka broken) CPU support:

   - Considerable fixes to support CPUs without the FP/SIMD extensions,
     including their presence in heterogeneous systems. Good luck
     finding a 64-bit userspace that handles this.

  Modern assembly function annotations:

   - Start migrating our use of ENTRY() and ENDPROC() over to the
     new-fangled SYM_{CODE,FUNC}_{START,END} macros, which are intended
     to aid debuggers

  Kbuild:

   - Cleanup detection of LSE support in the assembler by introducing
     'as-instr'

   - Remove compressed Image files when building clean targets

  IP checksumming:

   - Implement optimised IPv4 checksumming routine when hardware offload
     is not in use. An IPv6 version is in the works, pending testing.

  Hardware errata:

   - Work around Cortex-A55 erratum #1530923

  Shadow call stack:

   - Work around some issues with Clang's integrated assembler not
     liking our perfectly reasonable assembly code

   - Avoid allocating the X18 register, so that it can be used to hold
     the shadow call stack pointer in future

  ACPI:

   - Fix ID count checking in IORT code. This may regress broken
     firmware that happened to work with the old implementation, in
     which case we'll have to revert it and try something else

   - Fix DAIF corruption on return from GHES handler with pseudo-NMIs

  Miscellaneous:

   - Whitelist some CPUs that are unaffected by Spectre-v2

   - Reduce frequency of ASID rollover when KPTI is compiled in but
     inactive

   - Reserve a couple of arch-specific PROT flags that are already used
     by Sparc and PowerPC and are planned for later use with BTI on
     arm64

   - Preparatory cleanup of our entry assembly code in preparation for
     moving more of it into C later on

   - Refactoring and cleanup"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (73 commits)
  arm64: acpi: fix DAIF manipulation with pNMI
  arm64: kconfig: Fix alignment of E0PD help text
  arm64: Use v8.5-RNG entropy for KASLR seed
  arm64: Implement archrandom.h for ARMv8.5-RNG
  arm64: kbuild: remove compressed images on 'make ARCH=arm64 (dist)clean'
  arm64: entry: Avoid empty alternatives entries
  arm64: Kconfig: select HAVE_FUTEX_CMPXCHG
  arm64: csum: Fix pathological zero-length calls
  arm64: entry: cleanup sp_el0 manipulation
  arm64: entry: cleanup el0 svc handler naming
  arm64: entry: mark all entry code as notrace
  arm64: assembler: remove smp_dmb macro
  arm64: assembler: remove inherit_daif macro
  ACPI/IORT: Fix 'Number of IDs' handling in iort_id_map()
  mm: Reserve asm-generic prot flags 0x10 and 0x20 for arch use
  arm64: Use macros instead of hard-coded constants for MAIR_EL1
  arm64: Add KRYO{3,4}XX CPU cores to spectre-v2 safe list
  arm64: kernel: avoid x18 in __cpu_soft_restart
  arm64: kvm: stop treating register x18 as caller save
  arm64/lib: copy_page: avoid x18 register in assembler code
  ...
2020-01-27 08:58:19 -08:00
Steven Rostedt (VMware)
20279420ae tracing/kprobes: Have uname use __get_str() in print_fmt
Thomas Richter reported:

> Test case 66 'Use vfs_getname probe to get syscall args filenames'
> is broken on s390, but works on x86. The test case fails with:
>
>  [root@m35lp76 perf]# perf test -F 66
>  66: Use vfs_getname probe to get syscall args filenames
>            :Recording open file:
>  [ perf record: Woken up 1 times to write data ]
>  [ perf record: Captured and wrote 0.004 MB /tmp/__perf_test.perf.data.TCdYj\
> 	 (20 samples) ]
>  Looking at perf.data file for vfs_getname records for the file we touched:
>   FAILED!
>   [root@m35lp76 perf]#

The root cause was the print_fmt of the kprobe event that referenced the
"ustring"

> Setting up the kprobe event using perf command:
>
>  # ./perf probe "vfs_getname=getname_flags:72 pathname=filename:ustring"
>
> generates this format file:
>   [root@m35lp76 perf]# cat /sys/kernel/debug/tracing/events/probe/\
> 	  vfs_getname/format
>   name: vfs_getname
>   ID: 1172
>   format:
>     field:unsigned short common_type; offset:0; size:2; signed:0;
>     field:unsigned char common_flags; offset:2; size:1; signed:0;
>     field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
>     field:int common_pid; offset:4; size:4; signed:1;
>
>     field:unsigned long __probe_ip; offset:8; size:8; signed:0;
>     field:__data_loc char[] pathname; offset:16; size:4; signed:1;
>
>     print fmt: "(%lx) pathname=\"%s\"", REC->__probe_ip, REC->pathname

Instead of using "__get_str(pathname)" it referenced it directly.

Link: http://lkml.kernel.org/r/20200124100742.4050c15e@gandalf.local.home

Cc: stable@vger.kernel.org
Fixes: 88903c4643 ("tracing/probe: Add ustring type for user-space string")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-27 10:56:02 -05:00
David S. Miller
9e0703a265 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2020-01-27

The following pull-request contains BPF updates for your *net-next* tree.

We've added 20 non-merge commits during the last 5 day(s) which contain
a total of 24 files changed, 433 insertions(+), 104 deletions(-).

The main changes are:

1) Make BPF trampolines and dispatcher aware for the stack unwinder, from Jiri Olsa.

2) Improve handling of failed CO-RE relocations in libbpf, from Andrii Nakryiko.

3) Several fixes to BPF sockmap and reuseport selftests, from Lorenz Bauer.

4) Various cleanups in BPF devmap's XDP flush code, from John Fastabend.

5) Fix BPF flow dissector when used with port ranges, from Yoshiki Komachi.

6) Fix bpffs' map_seq_next callback to always inc position index, from Vasily Averin.

7) Allow overriding LLVM tooling for runqslower utility, from Andrey Ignatov.

8) Silence false-positive lockdep splats in devmap hash lookup, from Amol Grover.

9) Fix fentry/fexit selftests to initialize a variable before use, from John Sperbeck.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-27 14:31:40 +01:00
Rafael J. Wysocki
245224d1cb Merge branches 'pm-cpufreq' and 'pm-sleep'
* pm-cpufreq:
  cpufreq: loongson2_cpufreq: adjust cpufreq uses of LOONGSON_CHIPCFG
  cpufreq: brcmstb-avs: fix imbalance of cpufreq policy refcount
  cpufreq: intel_pstate: fix spelling mistake: "Whethet" -> "Whether"
  cpufreq: s3c: fix unbalances of cpufreq policy refcount
  cpufreq: imx-cpufreq-dt: Add i.MX8MP support
  cpufreq: Use imx-cpufreq-dt for i.MX8MP's speed grading
  cpufreq: tegra186: convert to devm_platform_ioremap_resource
  cpufreq: kirkwood: convert to devm_platform_ioremap_resource
  cpufreq: CPPC: put ACPI table after using it
  cpufreq : CPPC: Break out if HiSilicon CPPC workaround is matched

* pm-sleep:
  PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior
  PM: hibernate: fix spelling mistake "shapshot" -> "snapshot"
  PM: hibernate: Add more logging on hibernation failure
  PM: hibernate: improve arithmetic division in preallocate_highmem_fraction()
  PM: wakeup: Show statistics for deleted wakeup sources again
  PM: sleep: Switch to rtc_time64_to_tm()/rtc_tm_to_time64()
2020-01-27 11:29:09 +01:00
John Fastabend
b23bfa5633 bpf, xdp: Remove no longer required rcu_read_{un}lock()
Now that we depend on rcu_call() and synchronize_rcu() to also wait
for preempt_disabled region to complete the rcu read critical section
in __dev_map_flush() is no longer required. Except in a few special
cases in drivers that need it for other reasons.

These originally ensured the map reference was safe while a map was
also being free'd. And additionally that bpf program updates via
ndo_bpf did not happen while flush updates were in flight. But flush
by new rules can only be called from preempt-disabled NAPI context.
The synchronize_rcu from the map free path and the rcu_call from the
delete path will ensure the reference there is safe. So lets remove
the rcu_read_lock and rcu_read_unlock pair to avoid any confusion
around how this is being protected.

If the rcu_read_lock was required it would mean errors in the above
logic and the original patch would also be wrong.

Now that we have done above we put the rcu_read_lock in the driver
code where it is needed in a driver dependent way. I think this
helps readability of the code so we know where and why we are
taking read locks. Most drivers will not need rcu_read_locks here
and further XDP drivers already have rcu_read_locks in their code
paths for reading xdp programs on RX side so this makes it symmetric
where we don't have half of rcu critical sections define in driver
and the other half in devmap.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/1580084042-11598-4-git-send-email-john.fastabend@gmail.com
2020-01-27 11:16:25 +01:00
John Fastabend
42a84a8cd0 bpf, xdp: Update devmap comments to reflect napi/rcu usage
Now that we rely on synchronize_rcu and call_rcu waiting to
exit perempt-disable regions (NAPI) lets update the comments
to reflect this.

Fixes: 0536b85239 ("xdp: Simplify devmap cleanup")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/1580084042-11598-2-git-send-email-john.fastabend@gmail.com
2020-01-27 11:16:20 +01:00
Vasily Averin
90435a7891 bpf: map_seq_next should always increase position index
If seq_file .next fuction does not change position index,
read after some lseek can generate an unexpected output.

See also: https://bugzilla.kernel.org/show_bug.cgi?id=206283

v1 -> v2: removed missed increment in end of function

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/eca84fdd-c374-a154-d874-6c7b55fc3bc4@virtuozzo.com
2020-01-27 10:54:32 +01:00
Madhuparna Bhowmik
913292c97d sched.h: Annotate sighand_struct with __rcu
This patch fixes the following sparse errors by annotating the
sighand_struct with __rcu

kernel/fork.c:1511:9: error: incompatible types in comparison expression
kernel/exit.c💯19: error: incompatible types in comparison expression
kernel/signal.c:1370:27: error: incompatible types in comparison expression

This fix introduces the following sparse error in signal.c due to
checking the sighand pointer without rcu primitives:

kernel/signal.c:1386:21: error: incompatible types in comparison expression

This new sparse error is also fixed in this patch.

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20200124045908.26389-1-madhuparnabhowmik10@gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-01-26 10:54:47 +01:00
David S. Miller
4d8773b68e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Minor conflict in mlx5 because changes happened to code that has
moved meanwhile.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-26 10:40:21 +01:00
Paul E. McKenney
59d8cc6b2e rcu: Forgive slow expedited grace periods at boot time
Boot-time processing often loops in the kernel longer than one might
prefer, which can prevent expedited grace periods from completing in
a timely manner.  This in turn triggers a splat In nohz_full CPUs  One
could argue that long-looping code should be fixed, but on the other hand,
boot time is a bit special.

This commit therefore removes the splat.  Later commits will add the
splat back in, but in a way that removes false positives.

Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-25 12:00:40 -08:00
Steven Rostedt (VMware)
24589e3a20 tracing: Use pr_err() instead of WARN() for memory failures
As warnings can trigger panics, especially when "panic_on_warn" is set,
memory failure warnings can cause panics and fail fuzz testers that are
stressing memory.

Create a MEM_FAIL() macro to use instead of WARN() in the tracing code
(perhaps this should be a kernel wide macro?), and use that for memory
failure issues. This should stop failing fuzz tests due to warnings.

Link: https://lore.kernel.org/r/CACT4Y+ZP-7np20GVRu3p+eZys9GPtbu+JpfV+HtsufAzvTgJrg@mail.gmail.com

Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-25 10:52:30 -05:00
Jiri Olsa
e9b4e606c2 bpf: Allow to resolve bpf trampoline and dispatcher in unwind
When unwinding the stack we need to identify each address
to successfully continue. Adding latch tree to keep trampolines
for quick lookup during the unwind.

The patch uses first 48 bytes for latch tree node, leaving 4048
bytes from the rest of the page for trampoline or dispatcher
generated code.

It's still enough not to affect trampoline and dispatcher progs
maximum counts.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200123161508.915203-3-jolsa@kernel.org
2020-01-25 07:12:40 -08:00
Jiri Olsa
84ad7a7ab6 bpf: Allow BTF ctx access for string pointers
When accessing the context we allow access to arguments with
scalar type and pointer to struct. But we deny access for
pointer to scalar type, which is the case for many functions.

Alexei suggested to take conservative approach and allow
currently only string pointer access, which is the case
for most functions now:

Adding check if the pointer is to string type and allow access to it.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200123161508.915203-2-jolsa@kernel.org
2020-01-25 07:12:40 -08:00
Ingo Molnar
f8a4bb6bfa Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:

 - Expedited grace-period updates
 - kfree_rcu() updates
 - RCU list updates
 - Preemptible RCU updates
 - Torture-test updates
 - Miscellaneous fixes
 - Documentation updates

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-25 10:05:23 +01:00
Steven Rostedt (VMware)
28394da258 tracing: Decrement trace_array when bootconfig creates an instance
The trace_array_get_by_name() creates a ftrace instance and
trace_array_put() is used to remove the reference. Even though the
trace_array_get_by_name() creates the instance, it also adds a reference
count to it, that prevents user space from removing it.

As the bootconfig just creates the instance on boot up, it should still be
used where it can be deleted by user space after boot. A trace_array_put()
is required to let that happen.

Also, change the documentation on trace_array_get_by_name() to make this not
be so confusing.

Link: https://lore.kernel.org/r/20200124205927.76128804@rorschach.local.home

Fixes: 4f712a4d04 ("tracing/boot: Add instance node support")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-24 21:29:13 -05:00
Dan Carpenter
b3f7a6cd49 tracing: Remove unneeded NULL check
We checked "iter->trace" earlier so there is no need to check here.

Link: http://lkml.kernel.org/r/20141122183012.GB6994@mwanda

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-24 18:22:33 -05:00
Josef Bacik
cbc3b92ce0 tracing: Set kernel_stack's caller size properly
I noticed when trying to use the trace-cmd python interface that reading the raw
buffer wasn't working for kernel_stack events.  This is because it uses a
stubbed version of __dynamic_array that doesn't do the __data_loc trick and
encode the length of the array into the field.  Instead it just shows up as a
size of 0.  So change this to __array and set the len to FTRACE_STACK_ENTRIES
since this is what we actually do in practice and matches how user_stack_trace
works.

Link: http://lkml.kernel.org/r/1411589652-1318-1-git-send-email-jbacik@fb.com

Signed-off-by: Josef Bacik <jbacik@fb.com>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-24 18:09:40 -05:00
Luis Henriques
afccc00f75 tracing: Fix tracing_stat return values in error handling paths
tracing_stat_init() was always returning '0', even on the error paths.  It
now returns -ENODEV if tracing_init_dentry() fails or -ENOMEM if it fails
to created the 'trace_stat' debugfs directory.

Link: http://lkml.kernel.org/r/1410299381-20108-1-git-send-email-luis.henriques@canonical.com

Fixes: ed6f1c996b ("tracing: Check return value of tracing_init_dentry()")
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-24 18:06:48 -05:00
Steven Rostedt (VMware)
dfb6cd1e65 tracing: Fix very unlikely race of registering two stat tracers
Looking through old emails in my INBOX, I came across a patch from Luis
Henriques that attempted to fix a race of two stat tracers registering the
same stat trace (extremely unlikely, as this is done in the kernel, and
probably doesn't even exist). The submitted patch wasn't quite right as it
needed to deal with clean up a bit better (if two stat tracers were the
same, it would have the same files).

But to make the code cleaner, all we needed to do is to keep the
all_stat_sessions_mutex held for most of the registering function.

Link: http://lkml.kernel.org/r/1410299375-20068-1-git-send-email-luis.henriques@canonical.com

Fixes: 002bb86d8d ("tracing/ftrace: separate events tracing and stats tracing engine")
Reported-by: Luis Henriques <luis.henriques@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-24 17:54:06 -05:00
Stephen Boyd
fd928f3e32 alarmtimer: Make alarmtimer_get_rtcdev() a stub when CONFIG_RTC_CLASS=n
The stubbed version of alarmtimer_get_rtcdev() is not exported.
so this won't work if this function is used in a module when
CONFIG_RTC_CLASS=n.

Move the stub function to the header file and make it inline so that
callers don't have to worry about linking against this symbol.

rtcdev isn't used outside of this ifdef so it's not required to be
redefined to NULL. Drop that while touching this area.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200124055849.154411-4-swboyd@chromium.org
2020-01-24 21:03:53 +01:00
Stephen Boyd
7c94caca87 alarmtimer: Use wakeup source from alarmtimer platform device
Use the wakeup source that can be associated with the 'alarmtimer'
platform device instead of registering another one by hand.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200124055849.154411-3-swboyd@chromium.org
2020-01-24 21:00:21 +01:00
Stephen Boyd
c79108bd19 alarmtimer: Make alarmtimer platform device child of RTC device
The alarmtimer_suspend() function will fail if an RTC device is on a bus
such as SPI or i2c and that RTC device registers and probes after
alarmtimer_init() registers and probes the 'alarmtimer' platform device.

This is because system wide suspend suspends devices in the reverse order
of their probe. When alarmtimer_suspend() attempts to program the RTC for a
wakeup it will try to program an RTC device on a bus that has already been
suspended.

Move the alarmtimer device registration to happen when the RTC which is
used for wakeup is registered. Register the 'alarmtimer' platform device as
a child of the RTC device too, so that it can be guaranteed that the RTC
device won't be suspended when alarmtimer_suspend() is called.

Reported-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200124055849.154411-2-swboyd@chromium.org
2020-01-24 21:00:20 +01:00
Stephen Boyd
6b088cefbe alarmtimer: Update alarmtimer_get_rtcdev() docs to reflect reality
This function doesn't do anything like this comment says when an RTC device
hasn't been chosen. It looks like we used to do something like that before
commit 8bc0dafb5c ("alarmtimers: Rework RTC device selection using class
interface") but that's long gone now. Remove this sentence to avoid
confusing the reader.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200124055849.154411-5-swboyd@chromium.org
2020-01-24 21:00:20 +01:00
Sebastian Andrzej Siewior
cb923159bb smp: Remove allocation mask from on_each_cpu_cond.*()
The allocation mask is no longer used by on_each_cpu_cond() and
on_each_cpu_cond_mask() and can be removed.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20200117090137.1205765-4-bigeasy@linutronix.de
2020-01-24 20:40:09 +01:00
Sebastian Andrzej Siewior
67719ef25e smp: Add a smp_cond_func_t argument to smp_call_function_many()
on_each_cpu_cond_mask() allocates a new CPU mask. The newly allocated
mask is a subset of the provided mask based on the conditional function.

This memory allocation can be avoided by extending smp_call_function_many()
with the conditional function and performing the remote function call based
on the mask and the conditional function.

Rename smp_call_function_many() to smp_call_function_many_cond() and add
the smp_cond_func_t argument. If smp_cond_func_t is provided then it is
used before invoking the function.  Provide smp_call_function_many() with
cond_func set to NULL.  Let on_each_cpu_cond_mask() use
smp_call_function_many_cond().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20200117090137.1205765-3-bigeasy@linutronix.de
2020-01-24 20:40:09 +01:00
Sebastian Andrzej Siewior
5671d814db smp: Use smp_cond_func_t as type for the conditional function
Use a typdef for the conditional function instead defining it each time in
the function prototype.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20200117090137.1205765-2-bigeasy@linutronix.de
2020-01-24 20:40:08 +01:00
Thomas Gleixner
43ee74487b irqchip updates for Linux 5.6:
- Conversion of the SiFive PLIC to hierarchical domains
 - New SiFive GPIO irqchip driver
 - New Aspeed SCI irqchip driver
 - New NXP INTMUX irqchip driver
 - Additional support for the Meson A1 GPIO irqchip
 - First part of the GICv4.1 support
 - Assorted fixes
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Merge tag 'irqchip-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates from Marc Zyngier:

- Conversion of the SiFive PLIC to hierarchical domains
- New SiFive GPIO irqchip driver
- New Aspeed SCI irqchip driver
- New NXP INTMUX irqchip driver
- Additional support for the Meson A1 GPIO irqchip
- First part of the GICv4.1 support
- Assorted fixes
2020-01-24 20:08:51 +01:00
Paul E. McKenney
0e247386d9 Merge branches 'doc.2019.12.10a', 'exp.2019.12.09a', 'fixes.2020.01.24a', 'kfree_rcu.2020.01.24a', 'list.2020.01.10a', 'preempt.2020.01.24a' and 'torture.2019.12.09a' into HEAD
doc.2019.12.10a: Documentations updates
exp.2019.12.09a: Expedited grace-period updates
fixes.2020.01.24a: Miscellaneous fixes
kfree_rcu.2020.01.24a: Batch kfree_rcu() work
list.2020.01.10a: RCU-protected-list updates
preempt.2020.01.24a: Preemptible RCU updates
torture.2019.12.09a: Torture-test updates
2020-01-24 10:37:27 -08:00
Paul E. McKenney
f6105fc2a9 rcu: Remove unused stop-machine #include
Long ago, RCU used the stop-machine mechanism to implement expedited
grace periods, but no longer does so.  This commit therefore removes
the no-longer-needed #includes of linux/stop_machine.h.

Link: https://lwn.net/Articles/805317/
Reported-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:52 -08:00
Paul E. McKenney
844a378de3 srcu: Apply *_ONCE() to ->srcu_last_gp_end
The ->srcu_last_gp_end field is accessed from any CPU at any time
by synchronize_srcu(), so non-initialization references need to use
READ_ONCE() and WRITE_ONCE().  This commit therefore makes that change.

Reported-by: syzbot+08f3e9d26e5541e1ecf2@syzkaller.appspotmail.com
Acked-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:51 -08:00
Paul E. McKenney
7441e7661d rcu: Switch force_qs_rnp() to for_each_leaf_node_cpu_mask()
Currently, force_qs_rnp() uses a for_each_leaf_node_possible_cpu()
loop containing a check of the current CPU's bit in ->qsmask.
This works, but this commit saves three lines by instead using
for_each_leaf_node_cpu_mask(), which combines the functionality of
for_each_leaf_node_possible_cpu() and leaf_node_cpu_bit().  This commit
also replaces the use of the local variable "bit" with rdp->grpmask.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:51 -08:00
Ben Dooks
e1350e8e0e rcu: Move rcu_{expedited,normal} definitions into rcupdate.h
This commit moves the rcu_{expedited,normal} definitions from
kernel/rcu/update.c to include/linux/rcupdate.h to make sure they are
in sync, and also to avoid the following warning from sparse:

kernel/ksysfs.c:150:5: warning: symbol 'rcu_expedited' was not declared. Should it be static?
kernel/ksysfs.c:167:5: warning: symbol 'rcu_normal' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:50 -08:00
Lai Jiangshan
e2167b38c8 rcu: Move gp_state_names[] and gp_state_getname() to tree_stall.h
Only tree_stall.h needs to get name from GP state, so this commit
moves the gp_state_names[] array and the gp_state_getname()
from kernel/rcu/tree.h and kernel/rcu/tree.c, respectively, to
kernel/rcu/tree_stall.h.  While moving gp_state_names[], this commit
uses the GCC syntax to ensure that the right string is associated with
the right CPP macro.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:45 -08:00
Lai Jiangshan
4778339df0 rcu: Remove the declaration of call_rcu() in tree.h
The call_rcu() function is an external RCU API that is declared in
include/linux/rcupdate.h.  There is thus no point in redeclaring it
in kernel/rcu/tree.h, so this commit removes that redundant declaration.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:38 -08:00
Lai Jiangshan
2488a5e695 rcu: Fix tracepoint tracking RCU CPU kthread utilization
In the call to trace_rcu_utilization() at the start of the loop in
rcu_cpu_kthread(), "rcu_wait" is incorrect, plus this trace event needs
to be hoisted above the loop to balance with either the "rcu_wait" or
"rcu_yield", depending on how the loop exits.  This commit therefore
makes these changes.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:31 -08:00
Lai Jiangshan
822175e729 rcu: Fix harmless omission of "CONFIG_" from #if condition
The C preprocessor macros SRCU and TINY_RCU should instead be CONFIG_SRCU
and CONFIG_TINY_RCU, respectively in the #f in kernel/rcu/rcu.h. But
there is no harm when "TINY_RCU" is wrongly used, which are always
non-defined, which makes "!defined(TINY_RCU)" always true, which means
the code block is always included, and the included code block doesn't
cause any compilation error so far in CONFIG_TINY_RCU builds.  It is
also the reason this change should not be taken in -stable.

This commit adds the needed "CONFIG_" prefix to both macros.

Not for -stable.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:13 -08:00
Paul E. McKenney
5b14557b07 rcu: Avoid tick_dep_set_cpu() misordering
In the current code, rcu_nmi_enter_common() might decide to turn on
the tick using tick_dep_set_cpu(), but be delayed just before doing so.
Then the grace-period kthread might notice that the CPU in question had
in fact gone through a quiescent state, thus turning off the tick using
tick_dep_clear_cpu().  The later invocation of tick_dep_set_cpu() would
then incorrectly leave the tick on.

This commit therefore enlists the aid of the leaf rcu_node structure's
->lock to ensure that decisions to enable or disable the tick are
carried out before they can be reversed.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:27:33 -08:00
Lai Jiangshan
77339e61aa rcu: Provide wrappers for uses of ->rcu_read_lock_nesting
This commit provides wrapper functions for uses of ->rcu_read_lock_nesting
to improve readability and to ease future changes to support inlining
of __rcu_read_lock() and __rcu_read_unlock().

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:27:33 -08:00
Paul E. McKenney
c51f83c315 rcu: Use READ_ONCE() for ->expmask in rcu_read_unlock_special()
The rcu_node structure's ->expmask field is updated only when holding the
->lock, but is also accessed locklessly.  This means that all ->expmask
updates must use WRITE_ONCE() and all reads carried out without holding
->lock must use READ_ONCE().  This commit therefore changes the lockless
->expmask read in rcu_read_unlock_special() to use READ_ONCE().

Reported-by: syzbot+99f4ddade3c22ab0cf23@syzkaller.appspotmail.com
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Marco Elver <elver@google.com>
2020-01-24 10:27:33 -08:00
Lai Jiangshan
3717e1e9f2 rcu: Clear ->rcu_read_unlock_special only once
In rcu_preempt_deferred_qs_irqrestore(), ->rcu_read_unlock_special is
cleared one piece at a time.  Given that the "if" statements in this
function use the copy in "special", this commit removes the clearing
of the individual pieces in favor of clearing ->rcu_read_unlock_special
in one go just after it has been determined to be non-zero.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:27:33 -08:00
Lai Jiangshan
2eeba5838f rcu: Clear .exp_hint only when deferred quiescent state has been reported
Currently, the .exp_hint flag is cleared in rcu_read_unlock_special(),
which works, but which can also prevent subsequent rcu_read_unlock() calls
from helping expedite the quiescent state needed by an ongoing expedited
RCU grace period.  This commit therefore defers clearing of .exp_hint
from rcu_read_unlock_special() to rcu_preempt_deferred_qs_irqrestore(),
thus ensuring that intervening calls to rcu_read_unlock() have a chance
to help end the expedited grace period.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:27:33 -08:00
Lai Jiangshan
c130d2dc93 rcu: Rename some instance of CONFIG_PREEMPTION to CONFIG_PREEMPT_RCU
CONFIG_PREEMPTION and CONFIG_PREEMPT_RCU are always identical,
but some code depends on CONFIG_PREEMPTION to access to
rcu_preempt functionality. This patch changes CONFIG_PREEMPTION
to CONFIG_PREEMPT_RCU in these cases.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:26:28 -08:00
Joel Fernandes (Google)
189a6883dc rcu: Remove kfree_call_rcu_nobatch()
Now that the kfree_rcu() special-casing has been removed from tree RCU,
this commit removes kfree_call_rcu_nobatch() since it is no longer needed.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:24:31 -08:00
Joel Fernandes (Google)
77a40f9703 rcu: Remove kfree_rcu() special casing and lazy-callback handling
This commit removes kfree_rcu() special-casing and the lazy-callback
handling from Tree RCU.  It moves some of this special casing to Tiny RCU,
the removal of which will be the subject of later commits.

This results in a nice negative delta.

Suggested-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Add slab.h #include, thanks to kbuild test robot <lkp@intel.com>. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:24:31 -08:00
Joel Fernandes (Google)
e99637becb rcu: Add support for debug_objects debugging for kfree_rcu()
This commit applies RCU's debug_objects debugging to the new batched
kfree_rcu() implementations.  The object is queued at the kfree_rcu()
call and dequeued during reclaim.

Tested that enabling CONFIG_DEBUG_OBJECTS_RCU_HEAD successfully detects
double kfree_rcu() calls.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Fix IRQ per kbuild test robot <lkp@intel.com> feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:24:31 -08:00
Joel Fernandes (Google)
0392bebebf rcu: Add multiple in-flight batches of kfree_rcu() work
During testing, it was observed that amount of memory consumed due
kfree_rcu() batching is 300-400MB. Previously we had only a single
head_free pointer pointing to the list of rcu_head(s) that are to be
freed after a grace period. Until this list is drained, we cannot queue
any more objects on it since such objects may not be ready to be
reclaimed when the worker thread eventually gets to drainin g the
head_free list.

We can do better by maintaining multiple lists as done by this patch.
Testing shows that memory consumption came down by around 100-150MB with
just adding another list. Adding more than 1 additional list did not
show any improvement.

Suggested-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Code style and initialization handling. ]
[ paulmck: Fix field name, reported by kbuild test robot <lkp@intel.com>. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:24:31 -08:00
Joel Fernandes
569d767087 rcu: Make kfree_rcu() use a non-atomic ->monitor_todo
Because the ->monitor_todo field is always protected by krcp->lock,
this commit downgrades from xchg() to non-atomic unmarked assignment
statements.

Signed-off-by: Joel Fernandes <joel@joelfernandes.org>
[ paulmck: Update to include early-boot kick code. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:24:31 -08:00
Joel Fernandes (Google)
e6e78b004f rcuperf: Add kfree_rcu() performance Tests
This test runs kfree_rcu() in a loop to measure performance of the new
kfree_rcu() batching functionality.

The following table shows results when booting with arguments:
rcuperf.kfree_loops=20000 rcuperf.kfree_alloc_num=8000
rcuperf.kfree_rcu_test=1 rcuperf.kfree_no_batch=X

rcuperf.kfree_no_batch=X    # Grace Periods	Test Duration (s)
  X=1 (old behavior)              9133                 11.5
  X=0 (new behavior)              1732                 12.5

On a 16 CPU system with the above boot parameters, we see that the total
number of grace periods that elapse during the test drops from 9133 when
not batching to 1732 when batching (a 5X improvement). The kfree_rcu()
flood itself slows down a bit when batching, though, as shown.

Note that the active memory consumption during the kfree_rcu() flood
does increase to around 200-250MB due to the batching (from around 50MB
without batching). However, this memory consumption is relatively
constant. In other words, the system is able to keep up with the
kfree_rcu() load. The memory consumption comes down considerably if
KFREE_DRAIN_JIFFIES is increased from HZ/50 to HZ/80. A later patch will
reduce memory consumption further by using multiple lists.

Also, when running the test, please disable CONFIG_DEBUG_PREEMPT and
CONFIG_PROVE_RCU for realistic comparisons with/without batching.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:24:31 -08:00
Byungchul Park
a35d16905e rcu: Add basic support for kfree_rcu() batching
Recently a discussion about stability and performance of a system
involving a high rate of kfree_rcu() calls surfaced on the list [1]
which led to another discussion how to prepare for this situation.

This patch adds basic batching support for kfree_rcu(). It is "basic"
because we do none of the slab management, dynamic allocation, code
moving or any of the other things, some of which previous attempts did
[2]. These fancier improvements can be follow-up patches and there are
different ideas being discussed in those regards. This is an effort to
start simple, and build up from there. In the future, an extension to
use kfree_bulk and possibly per-slab batching could be done to further
improve performance due to cache-locality and slab-specific bulk free
optimizations. By using an array of pointers, the worker thread
processing the work would need to read lesser data since it does not
need to deal with large rcu_head(s) any longer.

Torture tests follow in the next patch and show improvements of around
5x reduction in number of  grace periods on a 16 CPU system. More
details and test data are in that patch.

There is an implication with rcu_barrier() with this patch. Since the
kfree_rcu() calls can be batched, and may not be handed yet to the RCU
machinery in fact, the monitor may not have even run yet to do the
queue_rcu_work(), there seems no easy way of implementing rcu_barrier()
to wait for those kfree_rcu()s that are already made. So this means a
kfree_rcu() followed by an rcu_barrier() does not imply that memory will
be freed once rcu_barrier() returns.

Another implication is higher active memory usage (although not
run-away..) until the kfree_rcu() flooding ends, in comparison to
without batching. More details about this are in the second patch which
adds an rcuperf test.

Finally, in the near future we will get rid of kfree_rcu() special casing
within RCU such as in rcu_do_batch and switch everything to just
batching. Currently we don't do that since timer subsystem is not yet up
and we cannot schedule the kfree_rcu() monitor as the timer subsystem's
lock are not initialized. That would also mean getting rid of
kfree_call_rcu_nobatch() entirely.

[1] http://lore.kernel.org/lkml/20190723035725-mutt-send-email-mst@kernel.org
[2] https://lkml.org/lkml/2017/12/19/824

Cc: kernel-team@android.com
Cc: kernel-team@lge.com
Co-developed-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Applied 0day and Paul Walmsley feedback on ->monitor_todo. ]
[ paulmck: Make it work during early boot. ]
[ paulmck: Add a crude early boot self-test. ]
[ paulmck: Style adjustments and experimental docbook structure header. ]
Link: https://lore.kernel.org/lkml/alpine.DEB.2.21.9999.1908161931110.32497@viisi.sifive.com/T/#me9956f66cb611b95d26ae92700e1d901f46e8c59
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:17:03 -08:00
Amol Grover
485ec2ea9c bpf, devmap: Pass lockdep expression to RCU lists
head is traversed using hlist_for_each_entry_rcu outside an RCU
read-side critical section but under the protection of dtab->index_lock.

Hence, add corresponding lockdep expression to silence false-positive
lockdep warnings, and harden RCU lists.

Fixes: 6f9d451ab1 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20200123120437.26506-1-frextrite@gmail.com
2020-01-23 23:01:16 +01:00
Linus Torvalds
34597c85be Various tracing fixes:
- Fix a function comparison warning for a xen trace event macro
  - Fix a double perf_event linking to a trace_uprobe_filter for multiple events
  - Fix suspicious RCU warnings in trace event code for using
     list_for_each_entry_rcu() when the "_rcu" portion wasn't needed.
  - Fix a bug in the histogram code when using the same variable
  - Fix a NULL pointer dereference when tracefs lockdown enabled and calling
     trace_set_default_clock()
 
 This v2 version contains:
 
  - A fix to a bug found with the double perf_event linking patch
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Merge tag 'trace-v5.5-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Various tracing fixes:

   - Fix a function comparison warning for a xen trace event macro

   - Fix a double perf_event linking to a trace_uprobe_filter for
     multiple events

   - Fix suspicious RCU warnings in trace event code for using
     list_for_each_entry_rcu() when the "_rcu" portion wasn't needed.

   - Fix a bug in the histogram code when using the same variable

   - Fix a NULL pointer dereference when tracefs lockdown enabled and
     calling trace_set_default_clock()

   - A fix to a bug found with the double perf_event linking patch"

* tag 'trace-v5.5-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/uprobe: Fix to make trace_uprobe_filter alignment safe
  tracing: Do not set trace clock if tracefs lockdown is in effect
  tracing: Fix histogram code when expression has same var as value
  tracing: trigger: Replace unneeded RCU-list traversals
  tracing/uprobe: Fix double perf_event linking on multiprobe uprobe
  tracing: xen: Ordered comparison of function pointers
2020-01-23 11:23:37 -08:00
Linus Torvalds
3a83c8c81c Power management fix for 5.5-rc8
Prevent the kernel from crashing during resume from hibernation
 if free pages contain leftover data from the restore kernel and
 init_on_free is set (Alexander Potapenko).
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Merge tag 'pm-5.5-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fix from Rafael Wysocki:
 "Prevent the kernel from crashing during resume from hibernation if
  free pages contain leftover data from the restore kernel and
  init_on_free is set (Alexander Potapenko)"

* tag 'pm-5.5-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: hibernate: fix crashes with init_on_free=1
2020-01-23 11:10:21 -08:00
Rafael J. Wysocki
322e929d19 Merge back new material related to system-wide PM for v5.6. 2020-01-23 16:00:56 +01:00
David S. Miller
954b3c4397 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-01-22

The following pull-request contains BPF updates for your *net-next* tree.

We've added 92 non-merge commits during the last 16 day(s) which contain
a total of 320 files changed, 7532 insertions(+), 1448 deletions(-).

The main changes are:

1) function by function verification and program extensions from Alexei.

2) massive cleanup of selftests/bpf from Toke and Andrii.

3) batched bpf map operations from Brian and Yonghong.

4) tcp congestion control in bpf from Martin.

5) bulking for non-map xdp_redirect form Toke.

6) bpf_send_signal_thread helper from Yonghong.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-23 08:10:16 +01:00
Martin KaFai Lau
5576b991e9 bpf: Add BPF_FUNC_jiffies64
This patch adds a helper to read the 64bit jiffies.  It will be used
in a later patch to implement the bpf_cubic.c.

The helper is inlined for jit_requested and 64 BITS_PER_LONG
as the map_gen_lookup().  Other cases could be considered together
with map_gen_lookup() if needed.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200122233646.903260-1-kafai@fb.com
2020-01-22 16:30:10 -08:00
Alexei Starovoitov
be8704ff07 bpf: Introduce dynamic program extensions
Introduce dynamic program extensions. The users can load additional BPF
functions and replace global functions in previously loaded BPF programs while
these programs are executing.

Global functions are verified individually by the verifier based on their types only.
Hence the global function in the new program which types match older function can
safely replace that corresponding function.

This new function/program is called 'an extension' of old program. At load time
the verifier uses (attach_prog_fd, attach_btf_id) pair to identify the function
to be replaced. The BPF program type is derived from the target program into
extension program. Technically bpf_verifier_ops is copied from target program.
The BPF_PROG_TYPE_EXT program type is a placeholder. It has empty verifier_ops.
The extension program can call the same bpf helper functions as target program.
Single BPF_PROG_TYPE_EXT type is used to extend XDP, SKB and all other program
types. The verifier allows only one level of replacement. Meaning that the
extension program cannot recursively extend an extension. That also means that
the maximum stack size is increasing from 512 to 1024 bytes and maximum
function nesting level from 8 to 16. The programs don't always consume that
much. The stack usage is determined by the number of on-stack variables used by
the program. The verifier could have enforced 512 limit for combined original
plus extension program, but it makes for difficult user experience. The main
use case for extensions is to provide generic mechanism to plug external
programs into policy program or function call chaining.

BPF trampoline is used to track both fentry/fexit and program extensions
because both are using the same nop slot at the beginning of every BPF
function. Attaching fentry/fexit to a function that was replaced is not
allowed. The opposite is true as well. Replacing a function that currently
being analyzed with fentry/fexit is not allowed. The executable page allocated
by BPF trampoline is not used by program extensions. This inefficiency will be
optimized in future patches.

Function by function verification of global function supports scalars and
pointer to context only. Hence program extensions are supported for such class
of global functions only. In the future the verifier will be extended with
support to pointers to structures, arrays with sizes, etc.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20200121005348.2769920-2-ast@kernel.org
2020-01-22 23:04:52 +01:00
Ming Lei
11ea68f553 genirq, sched/isolation: Isolate from handling managed interrupts
The affinity of managed interrupts is completely handled in the kernel and
cannot be changed via the /proc/irq/* interfaces from user space. As the
kernel tries to spread out interrupts evenly accross CPUs on x86 to prevent
vector exhaustion, it can happen that a managed interrupt whose affinity
mask contains both isolated and housekeeping CPUs is routed to an isolated
CPU. As a consequence IO submitted on a housekeeping CPU causes interrupts
on the isolated CPU.

Add a new sub-parameter 'managed_irq' for 'isolcpus' and the corresponding
logic in the interrupt affinity selection code.

The subparameter indicates to the interrupt affinity selection logic that
it should try to avoid the above scenario.

This isolation is best effort and only effective if the automatically
assigned interrupt mask of a device queue contains isolated and
housekeeping CPUs. If housekeeping CPUs are online then such interrupts are
directed to the housekeeping CPU so that IO submitted on the housekeeping
CPU cannot disturb the isolated CPU.

If a queue's affinity mask contains only isolated CPUs then this parameter
has no effect on the interrupt routing decision, though interrupts are only
happening when tasks running on those isolated CPUs submit IO. IO submitted
on housekeeping CPUs has no influence on those queues.

If the affinity mask contains both housekeeping and isolated CPUs, but none
of the contained housekeeping CPUs is online, then the interrupt is also
routed to an isolated CPU. Interrupts are only delivered when one of the
isolated CPUs in the affinity mask submits IO. If one of the contained
housekeeping CPUs comes online, the CPU hotplug logic migrates the
interrupt automatically back to the upcoming housekeeping CPU. Depending on
the type of interrupt controller, this can require that at least one
interrupt is delivered to the isolated CPU in order to complete the
migration.

[ tglx: Removed unused parameter, added and edited comments/documentation
  	and rephrased the changelog so it contains more details. ]

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200120091625.17912-1-ming.lei@redhat.com
2020-01-22 16:29:49 +01:00
Jules Irenge
eb5a4d0a9e hrtimer: Add missing sparse annotation for __run_timer()
Sparse reports a warning at __run_hrtimer()
|warning: context imbalance in __run_hrtimer() - unexpected unlock

Add the missing must_hold() annotation.

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200120224347.51843-1-jbi.octave@gmail.com
2020-01-22 15:50:11 +01:00
Masami Hiramatsu
b61387cb73 tracing/uprobe: Fix to make trace_uprobe_filter alignment safe
Commit 99c9a923e9 ("tracing/uprobe: Fix double perf_event
linking on multiprobe uprobe") moved trace_uprobe_filter on
trace_probe_event. However, since it introduced a flexible
data structure with char array and type casting, the
alignment of trace_uprobe_filter can be broken.

This changes the type of the array to trace_uprobe_filter
data strucure to fix it.

Link: http://lore.kernel.org/r/20200120124022.GA14897@hirez.programming.kicks-ass.net
Link: http://lkml.kernel.org/r/157966340499.5107.10978352478952144902.stgit@devnote2

Fixes: 99c9a923e9 ("tracing/uprobe: Fix double perf_event linking on multiprobe uprobe")
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-22 07:09:20 -05:00
Alex Shi
659ded3027 trace/kprobe: Remove unused MAX_KPROBE_CMDLINE_SIZE
This limitation are never lunched from introduce commit 970988e19e
("tracing/kprobe: Add kprobe_event= boot parameter")

Could we remove it if no intention to implement it?

Link: http://lkml.kernel.org/r/1579586075-45132-1-git-send-email-alex.shi@linux.alibaba.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-22 07:07:38 -05:00
Steven Rostedt (VMware)
34423f250a tracing: Fix uninitialized buffer var on early exit to trace_vbprintk()
If we exit due to a bad input to trace_printk() (highly unlikely), then the
buffer variable will not be initialized when we unnest the ring buffer.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-22 06:44:50 -05:00
Alexei Starovoitov
f59bbfc2f6 bpf: Fix error path under memory pressure
Restore the 'if (env->cur_state)' check that was incorrectly removed during
code move. Under memory pressure env->cur_state can be freed and zeroed inside
do_check(). Hence the check is necessary.

Fixes: 51c39bb1d5 ("bpf: Introduce function-by-function verification")
Reported-by: syzbot+b296579ba5015704d9fa@syzkaller.appspotmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200122024138.3385590-1-ast@kernel.org
2020-01-22 12:09:02 +01:00
Alexei Starovoitov
05d57f1793 bpf: Fix trampoline usage in preempt
Though the second half of trampoline page is unused a task could be
preempted in the middle of the first half of trampoline and two
updates to trampoline would change the code from underneath the
preempted task. Hence wait for tasks to voluntarily schedule or go
to userspace. Add similar wait before freeing the trampoline.

Fixes: fec56f5890 ("bpf: Introduce BPF trampoline")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/bpf/20200121032231.3292185-1-ast@kernel.org
2020-01-22 11:31:21 +01:00
Dan Carpenter
532f49a6f1 tracing/boot: Fix an IS_ERR() vs NULL bug
The trace_array_get_by_name() function doesn't return error pointers,
it returns NULL on error.

Link: http://lkml.kernel.org/r/20200117053007.5h2juv272pokqhtq@kili.mountain

Fixes: 4f712a4d04 ("tracing/boot: Add instance node support")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-21 18:41:39 -05:00
Alex Shi
141597204e tracing: Remove unused TRACE_SEQ_BUF_USED
This macro isn't used from commit 3a161d99c4 ("tracing: Create
seq_buf layer in trace_seq"). so no needs to keep it.

Link: http://lkml.kernel.org/r/1579586086-45543-1-git-send-email-alex.shi@linux.alibaba.com

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-21 18:39:54 -05:00
Alex Shi
b83479482f ring-buffer: Remove abandoned macro RB_MISSED_FLAGS
This macro isn't used since commit d325c40296 ("ring-buffer: Remove
unused function ring_buffer_page_len()"), so better to remove it.

Link: http://lkml.kernel.org/r/1579586080-45300-1-git-send-email-alex.shi@linux.alibaba.com

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-21 18:38:02 -05:00
Al Viro
b87121dd3f bpf: don't bother with getname/kern_path - use user_path_at
kernel/bpf/inode.c misuses kern_path...() - it's much simpler (and
more efficient, on top of that) to use user_path...() counterparts
rather than bothering with doing getname() manually.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200120232858.GF8904@ZenIV.linux.org.uk
2020-01-21 23:46:21 +01:00
Alex Shi
aff4866db5 ftrace: Remove NR_TO_INIT macro
This macro isn't used from commit cb7be3b2fc ("ftrace: remove
daemon"). So no needs to keep it.

Link: http://lkml.kernel.org/r/1579586063-44984-1-git-send-email-alex.shi@linux.alibaba.com

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-21 17:30:39 -05:00
Alex Shi
9a09cd74e7 ftrace: Remove abandoned macros
These 2 macros aren't used from commit eee8ded131 ("ftrace: Have the
function probes call their own function"), so remove them.

Link: http://lkml.kernel.org/r/1579585807-43316-1-git-send-email-alex.shi@linux.alibaba.com

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-21 17:28:35 -05:00
Brian Vazquez
2e3a94aa2b bpf: Fix memory leaks in generic update/delete batch ops
Generic update/delete batch ops functions were using __bpf_copy_key
without properly freeing the memory. Handle the memory allocation and
copy_from_user separately.

Fixes: aa2e93b8e5 ("bpf: Add generic support for update and delete batch ops")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200119194040.128369-1-brianvv@google.com
2020-01-20 22:27:51 +01:00
Masami Ichikawa
bf24daac8f tracing: Do not set trace clock if tracefs lockdown is in effect
When trace_clock option is not set and unstable clcok detected,
tracing_set_default_clock() sets trace_clock(ThinkPad A285 is one of
case). In that case, if lockdown is in effect, null pointer
dereference error happens in ring_buffer_set_clock().

Link: http://lkml.kernel.org/r/20200116131236.3866925-1-masami256@gmail.com

Cc: stable@vger.kernel.org
Fixes: 17911ff38a ("tracing: Add locked_down checks to the open calls of files created for tracefs")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1788488
Signed-off-by: Masami Ichikawa <masami256@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-20 16:18:14 -05:00
Steven Rostedt (VMware)
8bcebc77e8 tracing: Fix histogram code when expression has same var as value
While working on a tool to convert SQL syntex into the histogram language of
the kernel, I discovered the following bug:

 # echo 'first u64 start_time u64 end_time pid_t pid u64 delta' >> synthetic_events
 # echo 'hist:keys=pid:start=common_timestamp' > events/sched/sched_waking/trigger
 # echo 'hist:keys=next_pid:delta=common_timestamp-$start,start2=$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger

Would not display any histograms in the sched_switch histogram side.

But if I were to swap the location of

  "delta=common_timestamp-$start" with "start2=$start"

Such that the last line had:

 # echo 'hist:keys=next_pid:start2=$start,delta=common_timestamp-$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger

The histogram works as expected.

What I found out is that the expressions clear out the value once it is
resolved. As the variables are resolved in the order listed, when
processing:

  delta=common_timestamp-$start

The $start is cleared. When it gets to "start2=$start", it errors out with
"unresolved symbol" (which is silent as this happens at the location of the
trace), and the histogram is dropped.

When processing the histogram for variable references, instead of adding a
new reference for a variable used twice, use the same reference. That way,
not only is it more efficient, but the order will no longer matter in
processing of the variables.

From Tom Zanussi:

 "Just to clarify some more about what the problem was is that without
  your patch, we would have two separate references to the same variable,
  and during resolve_var_refs(), they'd both want to be resolved
  separately, so in this case, since the first reference to start wasn't
  part of an expression, it wouldn't get the read-once flag set, so would
  be read normally, and then the second reference would do the read-once
  read and also be read but using read-once.  So everything worked and
  you didn't see a problem:

   from: start2=$start,delta=common_timestamp-$start

  In the second case, when you switched them around, the first reference
  would be resolved by doing the read-once, and following that the second
  reference would try to resolve and see that the variable had already
  been read, so failed as unset, which caused it to short-circuit out and
  not do the trigger action to generate the synthetic event:

   to: delta=common_timestamp-$start,start2=$start

  With your patch, we only have the single resolution which happens
  correctly the one time it's resolved, so this can't happen."

Link: https://lore.kernel.org/r/20200116154216.58ca08eb@gandalf.local.home

Cc: stable@vger.kernel.org
Fixes: 067fe038e7 ("tracing: Add variable reference handling to hist triggers")
Reviewed-by: Tom Zanuss <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-20 16:11:47 -05:00
Kevin Hao
0f394daef8 irqdomain: Fix a memory leak in irq_domain_push_irq()
Fix a memory leak reported by kmemleak:
unreferenced object 0xffff000bc6f50e80 (size 128):
  comm "kworker/23:2", pid 201, jiffies 4294894947 (age 942.132s)
  hex dump (first 32 bytes):
    00 00 00 00 41 00 00 00 86 c0 03 00 00 00 00 00  ....A...........
    00 a0 b2 c6 0b 00 ff ff 40 51 fd 10 00 80 ff ff  ........@Q......
  backtrace:
    [<00000000e62d2240>] kmem_cache_alloc_trace+0x1a4/0x320
    [<00000000279143c9>] irq_domain_push_irq+0x7c/0x188
    [<00000000d9f4c154>] thunderx_gpio_probe+0x3ac/0x438
    [<00000000fd09ec22>] pci_device_probe+0xe4/0x198
    [<00000000d43eca75>] really_probe+0xdc/0x320
    [<00000000d3ebab09>] driver_probe_device+0x5c/0xf0
    [<000000005b3ecaa0>] __device_attach_driver+0x88/0xc0
    [<000000004e5915f5>] bus_for_each_drv+0x7c/0xc8
    [<0000000079d4db41>] __device_attach+0xe4/0x140
    [<00000000883bbda9>] device_initial_probe+0x18/0x20
    [<000000003be59ef6>] bus_probe_device+0x98/0xa0
    [<0000000039b03d3f>] deferred_probe_work_func+0x74/0xa8
    [<00000000870934ce>] process_one_work+0x1c8/0x470
    [<00000000e3cce570>] worker_thread+0x1f8/0x428
    [<000000005d64975e>] kthread+0xfc/0x128
    [<00000000f0eaa764>] ret_from_fork+0x10/0x18

Fixes: 495c38d300 ("irqdomain: Add irq_domain_{push,pop}_irq() functions")
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200120043547.22271-1-haokexin@gmail.com
2020-01-20 19:10:05 +00:00
Jessica Yu
708e0ada19 module: avoid setting info->name early in case we can fall back to info->mod->name
In setup_load_info(), info->name (which contains the name of the module,
mostly used for early logging purposes before the module gets set up)
gets unconditionally assigned if .modinfo is missing despite the fact
that there is an if (!info->name) check near the end of the function.
Avoid assigning a placeholder string to info->name if .modinfo doesn't
exist, so that we can fall back to info->mod->name later on.

Fixes: 5fdc7db644 ("module: setup load info before module_sig_check()")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-01-20 16:59:39 +01:00
Yash Shah
b01ecceaf2 genirq: Introduce irq_domain_translate_onecell
Add a new function irq_domain_translate_onecell() that is to be used as
the translate function in struct irq_domain_ops.

Signed-off-by: Yash Shah <yash.shah@sifive.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1575976274-13487-2-git-send-email-yash.shah@sifive.com
2020-01-20 09:19:33 +00:00
Ingo Molnar
cb6c82df68 Linux 5.5-rc7
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Merge tag 'v5.5-rc7' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-20 08:43:44 +01:00
Viresh Kumar
afa70d941f sched/fair: Define sched_idle_cpu() only for SMP configurations
sched_idle_cpu() isn't used for non SMP configuration and with a recent
change, we have started getting following warning:

  kernel/sched/fair.c:5221:12: warning: ‘sched_idle_cpu’ defined but not used [-Wunused-function]

Fix that by defining sched_idle_cpu() only for SMP configurations.

Fixes: 323af6deaf ("sched/fair: Load balance aggressively for SCHED_IDLE CPUs")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/f0554f590687478b33914a4aff9f0e6a62886d44.1579499907.git.viresh.kumar@linaro.org
2020-01-20 08:03:39 +01:00
Johannes Berg
87c9366e17 Revert "um: Enable CONFIG_CONSTRUCTORS"
This reverts commit 786b2384bf ("um: Enable CONFIG_CONSTRUCTORS").

There are two issues with this commit, uncovered by Anton in tests
on some (Debian) systems:

1) I completely forgot to call any constructors if CONFIG_CONSTRUCTORS
   isn't set. Don't recall now if it just wasn't needed on my system, or
   if I never tested this case.

2) With that fixed, it works - with CONFIG_CONSTRUCTORS *unset*. If I
   set CONFIG_CONSTRUCTORS, it fails again, which isn't totally
   unexpected since whatever wanted to run is likely to have to run
   before the kernel init etc. that calls the constructors in this case.

Basically, some constructors that gcc emits (libc has?) need to run
very early during init; the failure mode otherwise was that the ptrace
fork test already failed:

----------------------
$ ./linux mem=512M
Core dump limits :
	soft - 0
	hard - NONE
Checking that ptrace can change system call numbers...check_ptrace : child exited with exitcode 6, while expecting 0; status 0x67f
Aborted
----------------------

Thinking more about this, it's clear that we simply cannot support
CONFIG_CONSTRUCTORS in UML. All the cases we need now (gcov, kasan)
involve not use of the __attribute__((constructor)), but instead
some constructor code/entry generated by gcc. Therefore, we cannot
distinguish between kernel constructors and system constructors.

Thus, revert this commit.

Cc: stable@vger.kernel.org [5.4+]
Fixes: 786b2384bf ("um: Enable CONFIG_CONSTRUCTORS")
Reported-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.co.uk>

Signed-off-by: Richard Weinberger <richard@nod.at>
2020-01-19 22:42:06 +01:00
David S. Miller
b3f7e3f23a Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net 2020-01-19 22:10:04 +01:00
Linus Torvalds
11a8272947 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Fix non-blocking connect() in x25, from Martin Schiller.

 2) Fix spurious decryption errors in kTLS, from Jakub Kicinski.

 3) Netfilter use-after-free in mtype_destroy(), from Cong Wang.

 4) Limit size of TSO packets properly in lan78xx driver, from Eric
    Dumazet.

 5) r8152 probe needs an endpoint sanity check, from Johan Hovold.

 6) Prevent looping in tcp_bpf_unhash() during sockmap/tls free, from
    John Fastabend.

 7) hns3 needs short frames padded on transmit, from Yunsheng Lin.

 8) Fix netfilter ICMP header corruption, from Eyal Birger.

 9) Fix soft lockup when low on memory in hns3, from Yonglong Liu.

10) Fix NTUPLE firmware command failures in bnxt_en, from Michael Chan.

11) Fix memory leak in act_ctinfo, from Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (91 commits)
  cxgb4: reject overlapped queues in TC-MQPRIO offload
  cxgb4: fix Tx multi channel port rate limit
  net: sched: act_ctinfo: fix memory leak
  bnxt_en: Do not treat DSN (Digital Serial Number) read failure as fatal.
  bnxt_en: Fix ipv6 RFS filter matching logic.
  bnxt_en: Fix NTUPLE firmware command failures.
  net: systemport: Fixed queue mapping in internal ring map
  net: dsa: bcm_sf2: Configure IMP port for 2Gb/sec
  net: dsa: sja1105: Don't error out on disabled ports with no phy-mode
  net: phy: dp83867: Set FORCE_LINK_GOOD to default after reset
  net: hns: fix soft lockup when there is not enough memory
  net: avoid updating qdisc_xmit_lock_key in netdev_update_lockdep_key()
  net/sched: act_ife: initalize ife->metalist earlier
  netfilter: nat: fix ICMP header corruption on ICMP errors
  net: wan: lapbether.c: Use built-in RCU list checking
  netfilter: nf_tables: fix flowtable list del corruption
  netfilter: nf_tables: fix memory leak in nf_tables_parse_netdev_hooks()
  netfilter: nf_tables: remove WARN and add NLA_STRING upper limits
  netfilter: nft_tunnel: ERSPAN_VERSION must not be null
  netfilter: nft_tunnel: fix null-attribute check
  ...
2020-01-19 12:03:53 -08:00
Linus Torvalds
7ff15cd045 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar:
 "Three fixes: fix link failure on Alpha, fix a Sparse warning and
  annotate/robustify a lockless access in the NOHZ code"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/sched: Annotate lockless access to last_jiffies_update
  lib/vdso: Make __cvdso_clock_getres() static
  time/posix-stubs: Provide compat itimer supoprt for alpha
2020-01-18 13:00:59 -08:00
Linus Torvalds
9e79c52332 Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull cpu/SMT fix from Ingo Molnar:
 "Fix a build bug on CONFIG_HOTPLUG_SMT=y && !CONFIG_SYSFS kernels"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/SMT: Fix x86 link error without CONFIG_SYSFS
2020-01-18 12:57:41 -08:00
Linus Torvalds
b07b9e8d63 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Tooling fixes, three Intel uncore driver fixes, plus an AUX events fix
  uncovered by the perf fuzzer"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/uncore: Remove PCIe3 unit for SNR
  perf/x86/intel/uncore: Fix missing marker for snr_uncore_imc_freerunning_events
  perf/x86/intel/uncore: Add PCI ID of IMC for Xeon E3 V5 Family
  perf: Correctly handle failed perf_get_aux_event()
  perf hists: Fix variable name's inconsistency in hists__for_each() macro
  perf map: Set kmap->kmaps backpointer for main kernel map chunks
  perf report: Fix incorrectly added dimensions as switch perf data file
  tools lib traceevent: Fix memory leakage in filter_event
2020-01-18 12:55:19 -08:00
Linus Torvalds
124b5547ec Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "Three fixes:

    - Fix an rwsem spin-on-owner crash, introduced in v5.4

    - Fix a lockdep bug when running out of stack_trace entries,
      introduced in v5.4

    - Docbook fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwsem: Fix kernel crash when spinning on RWSEM_OWNER_UNKNOWN
  futex: Fix kernel-doc notation warning
  locking/lockdep: Fix buffer overrun problem in stack_trace[]
2020-01-18 12:53:28 -08:00
Linus Torvalds
ba0f472203 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull rseq fixes from Ingo Molnar:
 "Two rseq bugfixes:

   - CLONE_VM !CLONE_THREAD didn't work properly, the kernel would end
     up corrupting the TLS of the parent. Technically a change in the
     ABI but the previous behavior couldn't resonably have been relied
     on by applications so this looks like a valid exception to the ABI
     rule.

   - Make the RSEQ_FLAG_UNREGISTER ABI behavior consistent with the
     handling of other flags. This is not thought to impact any
     applications either"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rseq: Unregister rseq for clone CLONE_VM
  rseq: Reject unknown flags on rseq unregister
2020-01-18 12:29:13 -08:00
Linus Torvalds
8cac89909a for-linus-2020-01-18
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Merge tag 'for-linus-2020-01-18' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull thread fixes from Christian Brauner:
 "Here is an urgent fix for ptrace_may_access() permission checking.

  Commit 69f594a389 ("ptrace: do not audit capability check when
  outputing /proc/pid/stat") introduced the ability to opt out of audit
  messages for accesses to various proc files since they are not
  violations of policy.

  While doing so it switched the check from ns_capable() to
  has_ns_capability{_noaudit}(). That means it switched from checking
  the subjective credentials (ktask->cred) of the task to using the
  objective credentials (ktask->real_cred). This is appears to be wrong.
  ptrace_has_cap() is currently only used in ptrace_may_access() And is
  used to check whether the calling task (subject) has the
  CAP_SYS_PTRACE capability in the provided user namespace to operate on
  the target task (object). According to the cred.h comments this means
  the subjective credentials of the calling task need to be used.

  With this fix we switch ptrace_has_cap() to use security_capable() and
  thus back to using the subjective credentials.

  As one example where this might be particularly problematic, Jann
  pointed out that in combination with the upcoming IORING_OP_OPENAT{2}
  feature, this bug might allow unprivileged users to bypass the
  capability checks while asynchronously opening files like /proc/*/mem,
  because the capability checks for this would be performed against
  kernel credentials.

  To illustrate on the former point about this being exploitable: When
  io_uring creates a new context it records the subjective credentials
  of the caller. Later on, when it starts to do work it creates a kernel
  thread and registers a callback. The callback runs with kernel creds
  for ktask->real_cred and ktask->cred.

  To prevent this from becoming a full-blown 0-day io_uring will call
  override_cred() and override ktask->cred with the subjective
  credentials of the creator of the io_uring instance. With
  ptrace_has_cap() currently looking at ktask->real_cred this override
  will be ineffective and the caller will be able to open arbitray proc
  files as mentioned above.

  Luckily, this is currently not exploitable but would be so once
  IORING_OP_OPENAT{2} land in v5.6. Let's fix it now.

  To minimize potential regressions I successfully ran the criu
  testsuite. criu makes heavy use of ptrace() and extensively hits
  ptrace_may_access() codepaths and has a good change of detecting any
  regressions.

  Additionally, I succesfully ran the ptrace and seccomp kernel tests"

* tag 'for-linus-2020-01-18' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  ptrace: reintroduce usage of subjective credentials in ptrace_has_cap()
2020-01-18 12:23:31 -08:00
Christian Brauner
6b3ad6649a
ptrace: reintroduce usage of subjective credentials in ptrace_has_cap()
Commit 69f594a389 ("ptrace: do not audit capability check when outputing /proc/pid/stat")
introduced the ability to opt out of audit messages for accesses to various
proc files since they are not violations of policy.  While doing so it
somehow switched the check from ns_capable() to
has_ns_capability{_noaudit}(). That means it switched from checking the
subjective credentials of the task to using the objective credentials. This
is wrong since. ptrace_has_cap() is currently only used in
ptrace_may_access() And is used to check whether the calling task (subject)
has the CAP_SYS_PTRACE capability in the provided user namespace to operate
on the target task (object). According to the cred.h comments this would
mean the subjective credentials of the calling task need to be used.
This switches ptrace_has_cap() to use security_capable(). Because we only
call ptrace_has_cap() in ptrace_may_access() and in there we already have a
stable reference to the calling task's creds under rcu_read_lock() there's
no need to go through another series of dereferences and rcu locking done
in ns_capable{_noaudit}().

As one example where this might be particularly problematic, Jann pointed
out that in combination with the upcoming IORING_OP_OPENAT feature, this
bug might allow unprivileged users to bypass the capability checks while
asynchronously opening files like /proc/*/mem, because the capability
checks for this would be performed against kernel credentials.

To illustrate on the former point about this being exploitable: When
io_uring creates a new context it records the subjective credentials of the
caller. Later on, when it starts to do work it creates a kernel thread and
registers a callback. The callback runs with kernel creds for
ktask->real_cred and ktask->cred. To prevent this from becoming a
full-blown 0-day io_uring will call override_cred() and override
ktask->cred with the subjective credentials of the creator of the io_uring
instance. With ptrace_has_cap() currently looking at ktask->real_cred this
override will be ineffective and the caller will be able to open arbitray
proc files as mentioned above.
Luckily, this is currently not exploitable but will turn into a 0-day once
IORING_OP_OPENAT{2} land in v5.6. Fix it now!

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Jann Horn <jannh@google.com>
Fixes: 69f594a389 ("ptrace: do not audit capability check when outputing /proc/pid/stat")
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-01-18 13:51:39 +01:00
Thomas Gleixner
9f24c540f7 lib/vdso: Update coarse timekeeper unconditionally
The low resolution parts of the VDSO, i.e.:

  clock_gettime(CLOCK_*_COARSE), clock_getres(), time()

can be used even if there is no VDSO capable clocksource.

But if an architecture opts out of the VDSO data update then this
information becomes stale. This affects ARM when there is no architected
timer available. The lack of update causes userspace to use stale data
forever.

Make the update of the low resolution parts unconditional and only skip
the update of the high resolution parts if the architecture requests it.

Fixes: 44f57d788e ("timekeeping: Provide a generic update_vsyscall() implementation")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200114185946.765577901@linutronix.de
2020-01-17 15:53:50 +01:00
Thomas Gleixner
9a6b55ac4a lib/vdso: Make __arch_update_vdso_data() logic understandable
The function name suggests that this is a boolean checking whether the
architecture asks for an update of the VDSO data, but it works the other
way round. To spare further confusion invert the logic.

Fixes: 44f57d788e ("timekeeping: Provide a generic update_vsyscall() implementation")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200114185946.656652824@linutronix.de
2020-01-17 15:53:50 +01:00
Mark Rutland
da9ec3d3dd perf: Correctly handle failed perf_get_aux_event()
Vince reports a worrying issue:

| so I was tracking down some odd behavior in the perf_fuzzer which turns
| out to be because perf_even_open() sometimes returns 0 (indicating a file
| descriptor of 0) even though as far as I can tell stdin is still open.

... and further the cause:

| error is triggered if aux_sample_size has non-zero value.
|
| seems to be this line in kernel/events/core.c:
|
| if (perf_need_aux_event(event) && !perf_get_aux_event(event, group_leader))
|                goto err_locked;
|
| (note, err is never set)

This seems to be a thinko in commit:

  ab43762ef0 ("perf: Allow normal events to output AUX data")

... and we should probably return -EINVAL here, as this should only
happen when the new event is mis-configured or does not have a
compatible aux_event group leader.

Fixes: ab43762ef0 ("perf: Allow normal events to output AUX data")
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
2020-01-17 11:32:44 +01:00
Thomas Gleixner
11e31f608b watchdog/softlockup: Enforce that timestamp is valid on boot
Robert reported that during boot the watchdog timestamp is set to 0 for one
second which is the indicator for a watchdog reset.

The reason for this is that the timestamp is in seconds and the time is
taken from sched clock and divided by ~1e9. sched clock starts at 0 which
means that for the first second during boot the watchdog timestamp is 0,
i.e. reset.

Use ULONG_MAX as the reset indicator value so the watchdog works correctly
right from the start. ULONG_MAX would only conflict with a real timestamp
if the system reaches an uptime of 136 years on 32bit and almost eternity
on 64bit.

Reported-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/87o8v3uuzl.fsf@nanos.tec.linutronix.de
2020-01-17 11:19:22 +01:00
Waiman Long
f5bfdc8e39 locking/osq: Use optimized spinning loop for arm64
Arm64 has a more optimized spinning loop (atomic_cond_read_acquire)
using wfe for spinlock that can boost performance of sibling threads
by putting the current cpu to a wait state that is broken only when
the monitored variable changes or an external event happens.

OSQ has a more complicated spinning loop. Besides the lock value, it
also checks for need_resched() and vcpu_is_preempted(). The check for
need_resched() is not a problem as it is only set by the tick interrupt
handler. That will be detected by the spinning cpu right after iret.

The vcpu_is_preempted() check, however, is a problem as changes to the
preempt state of of previous node will not affect the wait state. For
ARM64, vcpu_is_preempted is not currently defined and so is a no-op.
Will has indicated that he is planning to para-virtualize wfe instead
of defining vcpu_is_preempted for PV support. So just add a comment in
arch/arm64/include/asm/spinlock.h to indicate that vcpu_is_preempted()
should not be defined as suggested.

On a 2-socket 56-core 224-thread ARM64 system, a kernel mutex locking
microbenchmark was run for 10s with and without the patch. The
performance numbers before patch were:

Running locktest with mutex [runtime = 10s, load = 1]
Threads = 224, Min/Mean/Max = 316/123,143/2,121,269
Threads = 224, Total Rate = 2,757 kop/s; Percpu Rate = 12 kop/s

After patch, the numbers were:

Running locktest with mutex [runtime = 10s, load = 1]
Threads = 224, Min/Mean/Max = 334/147,836/1,304,787
Threads = 224, Total Rate = 3,311 kop/s; Percpu Rate = 15 kop/s

So there was about 20% performance improvement.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20200113150735.21956-1-longman@redhat.com
2020-01-17 10:19:30 +01:00
Waiman Long
57097124cb locking/qspinlock: Fix inaccessible URL of MCS lock paper
It turns out that the URL of the MCS lock paper listed in the source
code is no longer accessible. I did got question about where the paper
was. This patch updates the URL to BZ 206115 which contains a copy of
the paper from

  https://www.cs.rochester.edu/u/scott/papers/1991_TOCS_synch.pdf

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20200107174914.4187-1-longman@redhat.com
2020-01-17 10:19:30 +01:00
Waiman Long
a030f9767d locking/lockdep: Fix lockdep_stats indentation problem
It was found that two lines in the output of /proc/lockdep_stats have
indentation problem:

  # cat /proc/lockdep_stats
     :
   in-process chains:                   25057
   stack-trace entries:                137827 [max: 524288]
   number of stack traces:        7973
   number of stack hash chains:   6355
   combined max dependencies:      1356414598
   hardirq-safe locks:                     57
   hardirq-unsafe locks:                 1286
     :

All the numbers displayed in /proc/lockdep_stats except the two stack
trace numbers are formatted with a field with of 11. To properly align
all the numbers, a field width of 11 is now added to the two stack
trace numbers.

Fixes: 8c779229d0 ("locking/lockdep: Report more stack trace statistics")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lkml.kernel.org/r/20191211213139.29934-1-longman@redhat.com
2020-01-17 10:19:30 +01:00
Waiman Long
39e7234f00 locking/rwsem: Fix kernel crash when spinning on RWSEM_OWNER_UNKNOWN
The commit 91d2a812df ("locking/rwsem: Make handoff writer
optimistically spin on owner") will allow a recently woken up waiting
writer to spin on the owner. Unfortunately, if the owner happens to be
RWSEM_OWNER_UNKNOWN, the code will incorrectly spin on it leading to a
kernel crash. This is fixed by passing the proper non-spinnable bits
to rwsem_spin_on_owner() so that RWSEM_OWNER_UNKNOWN will be treated
as a non-spinnable target.

Fixes: 91d2a812df ("locking/rwsem: Make handoff writer optimistically spin on owner")

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200115154336.8679-1-longman@redhat.com
2020-01-17 10:19:27 +01:00
Valentin Schneider
ccf74128d6 sched/topology: Assert non-NUMA topology masks don't (partially) overlap
topology.c::get_group() relies on the assumption that non-NUMA domains do
not partially overlap. Zeng Tao pointed out in [1] that such topology
descriptions, while completely bogus, can end up being exposed to the
scheduler.

In his example (8 CPUs, 2-node system), we end up with:
  MC span for CPU3 == 3-7
  MC span for CPU4 == 4-7

The first pass through get_group(3, sdd@MC) will result in the following
sched_group list:

  3 -> 4 -> 5 -> 6 -> 7
  ^                  /
   `----------------'

And a later pass through get_group(4, sdd@MC) will "corrupt" that to:

  3 -> 4 -> 5 -> 6 -> 7
       ^             /
	`-----------'

which will completely break things like 'while (sg != sd->groups)' when
using CPU3's base sched_domain.

There already are some architecture-specific checks in place such as
x86/kernel/smpboot.c::topology.sane(), but this is something we can detect
in the core scheduler, so it seems worthwhile to do so.

Warn and abort the construction of the sched domains if such a broken
topology description is detected. Note that this is somewhat
expensive (O(t.c²), 't' non-NUMA topology levels and 'c' CPUs) and could be
gated under SCHED_DEBUG if deemed necessary.

Testing
=======

Dietmar managed to reproduce this using the following qemu incantation:

  $ qemu-system-aarch64 -kernel ./Image -hda ./qemu-image-aarch64.img \
  -append 'root=/dev/vda console=ttyAMA0 loglevel=8 sched_debug' -smp \
  cores=8 --nographic -m 512 -cpu cortex-a53 -machine virt -numa \
  node,cpus=0-2,nodeid=0 -numa node,cpus=3-7,nodeid=1

alongside the following drivers/base/arch_topology.c hack (AIUI wouldn't be
needed if '-smp cores=X, sockets=Y' would work with qemu):

8<---
@@ -465,6 +465,9 @@ void update_siblings_masks(unsigned int cpuid)
 		if (cpuid_topo->package_id != cpu_topo->package_id)
 			continue;

+		if ((cpu < 4 && cpuid > 3) || (cpu > 3 && cpuid < 4))
+			continue;
+
 		cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
 		cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);

8<---

[1]: https://lkml.kernel.org/r/1577088979-8545-1-git-send-email-prime.zeng@hisilicon.com

Reported-by: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200115160915.22575-1-valentin.schneider@arm.com
2020-01-17 10:19:23 +01:00
Hewenliang
3e0de271ff idle: fix spelling mistake "iterrupts" -> "interrupts"
There is a spelling misake in comments of cpuidle_idle_call. Fix it.

Signed-off-by: Hewenliang <hewenliang4@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20200110025604.34373-1-hewenliang4@huawei.com
2020-01-17 10:19:22 +01:00
Vincent Guittot
a4f9a0e51b sched/fair: Remove redundant call to cpufreq_update_util()
With commit

  bef69dd878 ("sched/cpufreq: Move the cfs_rq_util_change() call to cpufreq_update_util()")

update_load_avg() has become the central point for calling cpufreq
(not including the update of blocked load). This change helps to
simplify further the number of calls to cpufreq_update_util() and to
remove last redundant ones. With update_load_avg(), we are now sure
that cpufreq_update_util() will be called after every task attachment
to a cfs_rq and especially after propagating this event down to the
util_avg of the root cfs_rq, which is the level that is used by
cpufreq governors like schedutil to set the frequency of a CPU.

The SCHED_CPUFREQ_MIGRATION flag forces an early call to cpufreq when
the migration happens in a cgroup whereas util_avg of root cfs_rq is
not yet updated and this call is duplicated with the one that happens
immediately after when the migration event reaches the root cfs_rq.
The dedicated flag SCHED_CPUFREQ_MIGRATION is now useless and can be
removed. The interface of attach_entity_load_avg() can also be
simplified accordingly.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/1579083620-24943-1-git-send-email-vincent.guittot@linaro.org
2020-01-17 10:19:22 +01:00
Wang Long
3d817689a6 sched/psi: create /proc/pressure and /proc/pressure/{io|memory|cpu} only when psi enabled
when CONFIG_PSI_DEFAULT_DISABLED set to N or the command line set psi=0,
I think we should not create /proc/pressure and
/proc/pressure/{io|memory|cpu}.

In the future, user maybe determine whether the psi feature is enabled by
checking the existence of the /proc/pressure dir or
/proc/pressure/{io|memory|cpu} files.

Signed-off-by: Wang Long <w@laoqinren.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lkml.kernel.org/r/1576672698-32504-1-git-send-email-w@laoqinren.net
2020-01-17 10:19:22 +01:00
Peng Liu
4c58f57fa6 sched/fair: Fix sgc->{min,max}_capacity calculation for SD_OVERLAP
commit bf475ce0a3 ("sched/fair: Add per-CPU min capacity to
sched_group_capacity") introduced per-cpu min_capacity.

commit e3d6d0cb66 ("sched/fair: Add sched_group per-CPU max capacity")
introduced per-cpu max_capacity.

In the SD_OVERLAP case, the local variable 'capacity' represents the sum
of CPU capacity of all CPUs in the first sched group (sg) of the sched
domain (sd).

It is erroneously used to calculate sg's min and max CPU capacity.
To fix this use capacity_of(cpu) instead of 'capacity'.

The code which achieves this via cpu_rq(cpu)->sd->groups->sgc->capacity
(for rq->sd != NULL) can be removed since it delivers the same value as
capacity_of(cpu) which is currently only used for the (!rq->sd) case
(see update_cpu_capacity()).
An sg of the lowest sd (rq->sd or sd->child == NULL) represents a single
CPU (and hence sg->sgc->capacity == capacity_of(cpu)).

Signed-off-by: Peng Liu <iwtbavbm@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20200104130828.GA7718@iZj6chx1xj0e0buvshuecpZ
2020-01-17 10:19:21 +01:00
Peng Wang
fe71bbb21e sched/fair: calculate delta runnable load only when it's needed
Move the code of calculation for delta_sum/delta_avg to where
it is really needed to be done.

Signed-off-by: Peng Wang <rocking@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20200103114400.17668-1-rocking@linux.alibaba.com
2020-01-17 10:19:21 +01:00
Alex Shi
9dec1b6949 sched/cputime: move rq parameter in irqtime_account_process_tick
Every time we call irqtime_account_process_tick() is in a interrupt,
Every caller will get and assign a parameter rq = this_rq(), This is
unnecessary and increase the code size a little bit. Move the rq getting
action to irqtime_account_process_tick internally is better.

             base               with this patch
cputime.o    578792 bytes        577888 bytes

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1577959674-255537-1-git-send-email-alex.shi@linux.alibaba.com
2020-01-17 10:19:21 +01:00
Yangtao Li
35f4cd96f5 stop_machine: Make stop_cpus() static
The function stop_cpus() is only used internally by the
stop_machine for stop multiple cpus.

Make it static.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20191228161912.24082-1-tiny.windzz@gmail.com
2020-01-17 10:19:21 +01:00
Wei Li
02d4ac5885 sched/debug: Reset watchdog on all CPUs while processing sysrq-t
Lengthy output of sysrq-t may take a lot of time on slow serial console
with lots of processes and CPUs.

So we need to reset NMI-watchdog to avoid spurious lockup messages, and
we also reset softlockup watchdogs on all other CPUs since another CPU
might be blocked waiting for us to process an IPI or stop_machine.

Add to sysrq_sched_debug_show() as what we did in show_state_filter().

Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20191226085224.48942-1-liwei391@huawei.com
2020-01-17 10:19:20 +01:00
Li Guanglei
dcd6dffb0a sched/core: Fix size of rq::uclamp initialization
rq::uclamp is an array of struct uclamp_rq, make sure we clear the
whole thing.

Fixes: 69842cba9a ("sched/uclamp: Add CPU's clamp buckets refcountinga")
Signed-off-by: Li Guanglei <guanglei.li@unisoc.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Qais Yousef <qais.yousef@arm.com>
Link: https://lkml.kernel.org/r/1577259844-12677-1-git-send-email-guangleix.li@gmail.com
2020-01-17 10:19:20 +01:00
Qais Yousef
7226017ad3 sched/uclamp: Fix a bug in propagating uclamp value in new cgroups
When a new cgroup is created, the effective uclamp value wasn't updated
with a call to cpu_util_update_eff() that looks at the hierarchy and
update to the most restrictive values.

Fix it by ensuring to call cpu_util_update_eff() when a new cgroup
becomes online.

Without this change, the newly created cgroup uses the default
root_task_group uclamp values, which is 1024 for both uclamp_{min, max},
which will cause the rq to to be clamped to max, hence cause the
system to run at max frequency.

The problem was observed on Ubuntu server and was reproduced on Debian
and Buildroot rootfs.

By default, Ubuntu and Debian create a cpu controller cgroup hierarchy
and add all tasks to it - which creates enough noise to keep the rq
uclamp value at max most of the time. Imitating this behavior makes the
problem visible in Buildroot too which otherwise looks fine since it's a
minimal userspace.

Fixes: 0b60ba2dd3 ("sched/uclamp: Propagate parent clamps")
Reported-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Doug Smythies <dsmythies@telus.net>
Link: https://lore.kernel.org/lkml/000701d5b965$361b6c60$a2524520$@net/
2020-01-17 10:19:20 +01:00
Viresh Kumar
323af6deaf sched/fair: Load balance aggressively for SCHED_IDLE CPUs
The fair scheduler performs periodic load balance on every CPU to check
if it can pull some tasks from other busy CPUs. The duration of this
periodic load balance is set to sd->balance_interval for the idle CPUs
and is calculated by multiplying the sd->balance_interval with the
sd->busy_factor (set to 32 by default) for the busy CPUs. The
multiplication is done for busy CPUs to avoid doing load balance too
often and rather spend more time executing actual task. While that is
the right thing to do for the CPUs busy with SCHED_OTHER or SCHED_BATCH
tasks, it may not be the optimal thing for CPUs running only SCHED_IDLE
tasks.

With the recent enhancements in the fair scheduler around SCHED_IDLE
CPUs, we now prefer to enqueue a newly-woken task to a SCHED_IDLE
CPU instead of other busy or idle CPUs. The same reasoning should be
applied to the load balancer as well to make it migrate tasks more
aggressively to a SCHED_IDLE CPU, as that will reduce the scheduling
latency of the migrated (SCHED_OTHER) tasks.

This patch makes minimal changes to the fair scheduler to do the next
load balance soon after the last non SCHED_IDLE task is dequeued from a
runqueue, i.e. making the CPU SCHED_IDLE. Also the sd->busy_factor is
ignored while calculating the balance_interval for such CPUs. This is
done to avoid delaying the periodic load balance by few hundred
milliseconds for SCHED_IDLE CPUs.

This is tested on ARM64 Hikey620 platform (octa-core) with the help of
rt-app and it is verified, using kernel traces, that the newly
SCHED_IDLE CPU does load balancing shortly after it becomes SCHED_IDLE
and pulls tasks from other busy CPUs.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/e485827eb8fe7db0943d6f3f6e0f5a4a70272781.1578471925.git.viresh.kumar@linaro.org
2020-01-17 10:19:20 +01:00
Vincent Guittot
5f68eb19b5 sched/fair : Improve update_sd_pick_busiest for spare capacity case
Similarly to calculate_imbalance() and find_busiest_group(), using the
number of idle CPUs when there is only 1 CPU in the group is not efficient
because we can't make a difference between a CPU running 1 task and a CPU
running dozens of small tasks competing for the same CPU but not enough
to overload it. More generally speaking, we should use the number of
running tasks when there is the same number of idle CPUs in a group instead
of blindly select the 1st one.

When the groups have spare capacity and the same number of idle CPUs, we
compare the number of running tasks to select the busiest group.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1576839893-26930-1-git-send-email-vincent.guittot@linaro.org
2020-01-17 10:19:19 +01:00
Jisheng Zhang
db5793c599 watchdog: Remove soft_lockup_hrtimer_cnt and related code
After commit 9cf57731b6 ("watchdog/softlockup: Replace "watchdog/%u"
threads with cpu_stop_work"), the percpu soft_lockup_hrtimer_cnt is
not used any more, so remove it and related code.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20191218131720.4146aea2@xhacker.debian
2020-01-17 10:19:19 +01:00
Steven Rostedt (VMware)
31537cf8f3 tracing: Initialize ret in syscall_enter_define_fields()
If syscall_enter_define_fields() is called on a system call with no
arguments, the return code variable "ret" will never get initialized.
Initialize it to zero.

Fixes: 04ae87a520 ("ftrace: Rework event_create_dir()")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/0FA8C6E3-D9F5-416D-A1B0-5E4CD583A101@lca.pw
2020-01-17 10:19:18 +01:00
YueHaibing
81f2b572cf bpf: Remove set but not used variable 'first_key'
kernel/bpf/syscall.c: In function generic_map_lookup_batch:
kernel/bpf/syscall.c:1339:7: warning: variable first_key set but not used [-Wunused-but-set-variable]

It is never used, so remove it.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Brian Vazquez <brianvv@google.com>
Link: https://lore.kernel.org/bpf/20200116145300.59056-1-yuehaibing@huawei.com
2020-01-16 20:15:24 -08:00
Jesper Dangaard Brouer
58aa94f922 devmap: Adjust tracepoint for map-less queue flush
Now that we don't have a reference to a devmap when flushing the device
bulk queue, let's change the the devmap_xmit tracepoint to remote the
map_id and map_index fields entirely. Rearrange the fields so 'drops' and
'sent' stay in the same position in the tracepoint struct, to make it
possible for the xdp_monitor utility to read both the old and the new
format.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/157918768613.1458396.9165902403373826572.stgit@toke.dk
2020-01-16 20:03:34 -08:00
Toke Høiland-Jørgensen
1d233886dd xdp: Use bulking for non-map XDP_REDIRECT and consolidate code paths
Since the bulk queue used by XDP_REDIRECT now lives in struct net_device,
we can re-use the bulking for the non-map version of the bpf_redirect()
helper. This is a simple matter of having xdp_do_redirect_slow() queue the
frame on the bulk queue instead of sending it out with __bpf_tx_xdp().

Unfortunately we can't make the bpf_redirect() helper return an error if
the ifindex doesn't exit (as bpf_redirect_map() does), because we don't
have a reference to the network namespace of the ingress device at the time
the helper is called. So we have to leave it as-is and keep the device
lookup in xdp_do_redirect_slow().

Since this leaves less reason to have the non-map redirect code in a
separate function, so we get rid of the xdp_do_redirect_slow() function
entirely. This does lose us the tracepoint disambiguation, but fortunately
the xdp_redirect and xdp_redirect_map tracepoints use the same tracepoint
entry structures. This means both can contain a map index, so we can just
amend the tracepoint definitions so we always emit the xdp_redirect(_err)
tracepoints, but with the map ID only populated if a map is present. This
means we retire the xdp_redirect_map(_err) tracepoints entirely, but keep
the definitions around in case someone is still listening for them.

With this change, the performance of the xdp_redirect sample program goes
from 5Mpps to 8.4Mpps (a 68% increase).

Since the flush functions are no longer map-specific, rename the flush()
functions to drop _map from their names. One of the renamed functions is
the xdp_do_flush_map() callback used in all the xdp-enabled drivers. To
keep from having to update all drivers, use a #define to keep the old name
working, and only update the virtual drivers in this patch.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/157918768505.1458396.17518057312953572912.stgit@toke.dk
2020-01-16 20:03:34 -08:00
Toke Høiland-Jørgensen
75ccae62cb xdp: Move devmap bulk queue into struct net_device
Commit 96360004b8 ("xdp: Make devmap flush_list common for all map
instances"), changed devmap flushing to be a global operation instead of a
per-map operation. However, the queue structure used for bulking was still
allocated as part of the containing map.

This patch moves the devmap bulk queue into struct net_device. The
motivation for this is reusing it for the non-map variant of XDP_REDIRECT,
which will be changed in a subsequent commit.  To avoid other fields of
struct net_device moving to different cache lines, we also move a couple of
other members around.

We defer the actual allocation of the bulk queue structure until the
NETDEV_REGISTER notification devmap.c. This makes it possible to check for
ndo_xdp_xmit support before allocating the structure, which is not possible
at the time struct net_device is allocated. However, we keep the freeing in
free_netdev() to avoid adding another RCU callback on NETDEV_UNREGISTER.

Because of this change, we lose the reference back to the map that
originated the redirect, so change the tracepoint to always return 0 as the
map ID and index. Otherwise no functional change is intended with this
patch.

After this patch, the relevant part of struct net_device looks like this,
according to pahole:

	/* --- cacheline 14 boundary (896 bytes) --- */
	struct netdev_queue *      _tx __attribute__((__aligned__(64))); /*   896     8 */
	unsigned int               num_tx_queues;        /*   904     4 */
	unsigned int               real_num_tx_queues;   /*   908     4 */
	struct Qdisc *             qdisc;                /*   912     8 */
	unsigned int               tx_queue_len;         /*   920     4 */
	spinlock_t                 tx_global_lock;       /*   924     4 */
	struct xdp_dev_bulk_queue * xdp_bulkq;           /*   928     8 */
	struct xps_dev_maps *      xps_cpus_map;         /*   936     8 */
	struct xps_dev_maps *      xps_rxqs_map;         /*   944     8 */
	struct mini_Qdisc *        miniq_egress;         /*   952     8 */
	/* --- cacheline 15 boundary (960 bytes) --- */
	struct hlist_head  qdisc_hash[16];               /*   960   128 */
	/* --- cacheline 17 boundary (1088 bytes) --- */
	struct timer_list  watchdog_timer;               /*  1088    40 */

	/* XXX last struct has 4 bytes of padding */

	int                        watchdog_timeo;       /*  1128     4 */

	/* XXX 4 bytes hole, try to pack */

	struct list_head   todo_list;                    /*  1136    16 */
	/* --- cacheline 18 boundary (1152 bytes) --- */

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/157918768397.1458396.12673224324627072349.stgit@toke.dk
2020-01-16 20:03:34 -08:00
Alexander Potapenko
18451f9f9e PM: hibernate: fix crashes with init_on_free=1
Upon resuming from hibernation, free pages may contain stale data from
the kernel that initiated the resume. This breaks the invariant
inflicted by init_on_free=1 that freed pages must be zeroed.

To deal with this problem, make clear_free_pages() also clear the free
pages when init_on_free is enabled.

Fixes: 6471384af2 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options")
Reported-by: Johannes Stezenbach <js@sig21.net>
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: 5.3+ <stable@vger.kernel.org> # 5.3+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-01-16 23:51:45 +01:00
Jonas Meurer
c052bf82c6 PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior
The sysfs attribute `/sys/power/sync_on_suspend` controls, whether or not
filesystems are synced by the kernel before system suspend.

Congruously, the behaviour of build-time switch CONFIG_SUSPEND_SKIP_SYNC
is slightly changed: It now defines the run-tim default for the new sysfs
attribute `/sys/power/sync_on_suspend`.

The run-time attribute is added because the existing corresponding
build-time Kconfig flag for (`CONFIG_SUSPEND_SKIP_SYNC`) is not flexible
enough. E.g. Linux distributions that provide pre-compiled kernels
usually want to stick with the default (sync filesystems before suspend)
but under special conditions this needs to be changed.

One example for such a special condition is user-space handling of
suspending block devices (e.g. using `cryptsetup luksSuspend` or `dmsetup
suspend`) before system suspend. The Kernel trying to sync filesystems
after the underlying block device already got suspended obviously leads
to dead-locks. Be aware that you have to take care of the filesystem sync
yourself before suspending the system in those scenarios.

Signed-off-by: Jonas Meurer <jonas@freesources.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-01-16 21:47:03 +01:00
Petr Mladek
3a51449b79 watchdog/softlockup: Remove obsolete check of last reported task
commit 9cf57731b6 ("watchdog/softlockup: Replace "watchdog/%u" threads
 with cpu_stop_work") ensures that the watchdog is reliably touched during
a task switch.

As a result the check for an unnoticed task switch is not longer needed.

Remove the relevant code, which effectively reverts commit b1a8de1f53
("softlockup: make detector be aware of task switch of processes hogging
cpu")

Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Ziljstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20191024114928.15377-2-pmladek@suse.com
2020-01-16 14:52:48 +01:00
Steven Rostedt (VMware)
82d1b8158c tracing: Allow trace_printk() to nest in other tracing code
trace_printk() is used to debug the kernel which includes the tracing
infrastructure. But because it writes to the ring buffer, and so does much
of the tracing infrastructure, the ring buffer's recursive detection will
drop writes to the ring buffer that is in the same context as the current
write is happening (it allows interrupts to write when normal context is
writing, but wont let normal context write while normal context is writing).

This can cause confusion and think that the code is where the trace_printk()
exists is not hit. To solve this, up the recursive nesting of the ring
buffer when trace_printk() is called before it writes to the buffer itself.

Note, this does make it dangerous to use trace_printk() in the ring buffer
code itself, because this basically disables the recursion protection of
trace_printk() buffer writes. But as trace_printk() is only used for
debugging, and if this does occur, the developer will see the cause real
quick (recursive blowing up of the stack). Thus the developer can deal with
that. But having trace_printk() silently ignored is a much bigger problem,
and disabling recursive protection is a small price to pay to fix it.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-16 08:20:18 -05:00
Jisheng Zhang
d129479f1f watchdog: Remove soft_lockup_hrtimer_cnt and related code
After commit 9cf57731b6 ("watchdog/softlockup: Replace "watchdog/%u"
threads with cpu_stop_work"), the percpu soft_lockup_hrtimer_cnt is
not used any more, so remove it and related code.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191218131720.4146aea2@xhacker.debian
2020-01-16 12:25:51 +01:00
David S. Miller
3981f955eb Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2020-01-15

The following pull-request contains BPF updates for your *net* tree.

We've added 12 non-merge commits during the last 9 day(s) which contain
a total of 13 files changed, 95 insertions(+), 43 deletions(-).

The main changes are:

1) Fix refcount leak for TCP time wait and request sockets for socket lookup
   related BPF helpers, from Lorenz Bauer.

2) Fix wrong verification of ARSH instruction under ALU32, from Daniel Borkmann.

3) Batch of several sockmap and related TLS fixes found while operating
   more complex BPF programs with Cilium and OpenSSL, from John Fastabend.

4) Fix sockmap to read psock's ingress_msg queue before regular sk_receive_queue()
   to avoid purging data upon teardown, from Lingpeng Chen.

5) Fix printing incorrect pointer in bpftool's btf_dump_ptr() in order to properly
   dump a BPF map's value with BTF, from Martin KaFai Lau.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-16 10:04:40 +01:00
Yonghong Song
057996380a bpf: Add batch ops to all htab bpf map
htab can't use generic batch support due some problematic behaviours
inherent to the data structre, i.e. while iterating the bpf map  a
concurrent program might delete the next entry that batch was about to
use, in that case there's no easy solution to retrieve the next entry,
the issue has been discussed multiple times (see [1] and [2]).

The only way hmap can be traversed without the problem previously
exposed is by making sure that the map is traversing entire buckets.
This commit implements those strict requirements for hmap, the
implementation follows the same interaction that generic support with
some exceptions:

 - If keys/values buffer are not big enough to traverse a bucket,
   ENOSPC will be returned.
 - out_batch contains the value of the next bucket in the iteration, not
   the next key, but this is transparent for the user since the user
   should never use out_batch for other than bpf batch syscalls.

This commits implements BPF_MAP_LOOKUP_BATCH and adds support for new
command BPF_MAP_LOOKUP_AND_DELETE_BATCH. Note that for update/delete
batch ops it is possible to use the generic implementations.

[1] https://lore.kernel.org/bpf/20190724165803.87470-1-brianvv@google.com/
[2] https://lore.kernel.org/bpf/20190906225434.3635421-1-yhs@fb.com/

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115184308.162644-6-brianvv@google.com
2020-01-15 14:00:35 -08:00
Brian Vazquez
c60f2d2861 bpf: Add lookup and update batch ops to arraymap
This adds the generic batch ops functionality to bpf arraymap, note that
since deletion is not a valid operation for arraymap, only batch and
lookup are added.

Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200115184308.162644-5-brianvv@google.com
2020-01-15 14:00:35 -08:00
Brian Vazquez
aa2e93b8e5 bpf: Add generic support for update and delete batch ops
This commit adds generic support for update and delete batch ops that
can be used for almost all the bpf maps. These commands share the same
UAPI attr that lookup and lookup_and_delete batch ops use and the
syscall commands are:

  BPF_MAP_UPDATE_BATCH
  BPF_MAP_DELETE_BATCH

The main difference between update/delete and lookup batch ops is that
for update/delete keys/values must be specified for userspace and
because of that, neither in_batch nor out_batch are used.

Suggested-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115184308.162644-4-brianvv@google.com
2020-01-15 14:00:35 -08:00
Brian Vazquez
cb4d03ab49 bpf: Add generic support for lookup batch op
This commit introduces generic support for the bpf_map_lookup_batch.
This implementation can be used by almost all the bpf maps since its core
implementation is relying on the existing map_get_next_key and
map_lookup_elem. The bpf syscall subcommand introduced is:

  BPF_MAP_LOOKUP_BATCH

The UAPI attribute is:

  struct { /* struct used by BPF_MAP_*_BATCH commands */
         __aligned_u64   in_batch;       /* start batch,
                                          * NULL to start from beginning
                                          */
         __aligned_u64   out_batch;      /* output: next start batch */
         __aligned_u64   keys;
         __aligned_u64   values;
         __u32           count;          /* input/output:
                                          * input: # of key/value
                                          * elements
                                          * output: # of filled elements
                                          */
         __u32           map_fd;
         __u64           elem_flags;
         __u64           flags;
  } batch;

in_batch/out_batch are opaque values use to communicate between
user/kernel space, in_batch/out_batch must be of key_size length.

To start iterating from the beginning in_batch must be null,
count is the # of key/value elements to retrieve. Note that the 'keys'
buffer must be a buffer of key_size * count size and the 'values' buffer
must be value_size * count, where value_size must be aligned to 8 bytes
by userspace if it's dealing with percpu maps. 'count' will contain the
number of keys/values successfully retrieved. Note that 'count' is an
input/output variable and it can contain a lower value after a call.

If there's no more entries to retrieve, ENOENT will be returned. If error
is ENOENT, count might be > 0 in case it copied some values but there were
no more entries to retrieve.

Note that if the return code is an error and not -EFAULT,
count indicates the number of elements successfully processed.

Suggested-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115184308.162644-3-brianvv@google.com
2020-01-15 14:00:35 -08:00
Brian Vazquez
15c14a3dca bpf: Add bpf_map_{value_size, update_value, map_copy_value} functions
This commit moves reusable code from map_lookup_elem and map_update_elem
to avoid code duplication in kernel/bpf/syscall.c.

Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200115184308.162644-2-brianvv@google.com
2020-01-15 14:00:34 -08:00
Daniel Borkmann
0af2ffc93a bpf: Fix incorrect verifier simulation of ARSH under ALU32
Anatoly has been fuzzing with kBdysch harness and reported a hang in one
of the outcomes:

  0: R1=ctx(id=0,off=0,imm=0) R10=fp0
  0: (85) call bpf_get_socket_cookie#46
  1: R0_w=invP(id=0) R10=fp0
  1: (57) r0 &= 808464432
  2: R0_w=invP(id=0,umax_value=808464432,var_off=(0x0; 0x30303030)) R10=fp0
  2: (14) w0 -= 810299440
  3: R0_w=invP(id=0,umax_value=4294967295,var_off=(0xcf800000; 0x3077fff0)) R10=fp0
  3: (c4) w0 s>>= 1
  4: R0_w=invP(id=0,umin_value=1740636160,umax_value=2147221496,var_off=(0x67c00000; 0x183bfff8)) R10=fp0
  4: (76) if w0 s>= 0x30303030 goto pc+216
  221: R0_w=invP(id=0,umin_value=1740636160,umax_value=2147221496,var_off=(0x67c00000; 0x183bfff8)) R10=fp0
  221: (95) exit
  processed 6 insns (limit 1000000) [...]

Taking a closer look, the program was xlated as follows:

  # ./bpftool p d x i 12
  0: (85) call bpf_get_socket_cookie#7800896
  1: (bf) r6 = r0
  2: (57) r6 &= 808464432
  3: (14) w6 -= 810299440
  4: (c4) w6 s>>= 1
  5: (76) if w6 s>= 0x30303030 goto pc+216
  6: (05) goto pc-1
  7: (05) goto pc-1
  8: (05) goto pc-1
  [...]
  220: (05) goto pc-1
  221: (05) goto pc-1
  222: (95) exit

Meaning, the visible effect is very similar to f54c7898ed ("bpf: Fix
precision tracking for unbounded scalars"), that is, the fall-through
branch in the instruction 5 is considered to be never taken given the
conclusion from the min/max bounds tracking in w6, and therefore the
dead-code sanitation rewrites it as goto pc-1. However, real-life input
disagrees with verification analysis since a soft-lockup was observed.

The bug sits in the analysis of the ARSH. The definition is that we shift
the target register value right by K bits through shifting in copies of
its sign bit. In adjust_scalar_min_max_vals(), we do first coerce the
register into 32 bit mode, same happens after simulating the operation.
However, for the case of simulating the actual ARSH, we don't take the
mode into account and act as if it's always 64 bit, but location of sign
bit is different:

  dst_reg->smin_value >>= umin_val;
  dst_reg->smax_value >>= umin_val;
  dst_reg->var_off = tnum_arshift(dst_reg->var_off, umin_val);

Consider an unknown R0 where bpf_get_socket_cookie() (or others) would
for example return 0xffff. With the above ARSH simulation, we'd see the
following results:

  [...]
  1: R1=ctx(id=0,off=0,imm=0) R2_w=invP65535 R10=fp0
  1: (85) call bpf_get_socket_cookie#46
  2: R0_w=invP(id=0) R10=fp0
  2: (57) r0 &= 808464432
    -> R0_runtime = 0x3030
  3: R0_w=invP(id=0,umax_value=808464432,var_off=(0x0; 0x30303030)) R10=fp0
  3: (14) w0 -= 810299440
    -> R0_runtime = 0xcfb40000
  4: R0_w=invP(id=0,umax_value=4294967295,var_off=(0xcf800000; 0x3077fff0)) R10=fp0
                              (0xffffffff)
  4: (c4) w0 s>>= 1
    -> R0_runtime = 0xe7da0000
  5: R0_w=invP(id=0,umin_value=1740636160,umax_value=2147221496,var_off=(0x67c00000; 0x183bfff8)) R10=fp0
                              (0x67c00000)           (0x7ffbfff8)
  [...]

In insn 3, we have a runtime value of 0xcfb40000, which is '1100 1111 1011
0100 0000 0000 0000 0000', the result after the shift has 0xe7da0000 that
is '1110 0111 1101 1010 0000 0000 0000 0000', where the sign bit is correctly
retained in 32 bit mode. In insn4, the umax was 0xffffffff, and changed into
0x7ffbfff8 after the shift, that is, '0111 1111 1111 1011 1111 1111 1111 1000'
and means here that the simulation didn't retain the sign bit. With above
logic, the updates happen on the 64 bit min/max bounds and given we coerced
the register, the sign bits of the bounds are cleared as well, meaning, we
need to force the simulation into s32 space for 32 bit alu mode.

Verification after the fix below. We're first analyzing the fall-through branch
on 32 bit signed >= test eventually leading to rejection of the program in this
specific case:

  0: R1=ctx(id=0,off=0,imm=0) R10=fp0
  0: (b7) r2 = 808464432
  1: R1=ctx(id=0,off=0,imm=0) R2_w=invP808464432 R10=fp0
  1: (85) call bpf_get_socket_cookie#46
  2: R0_w=invP(id=0) R10=fp0
  2: (bf) r6 = r0
  3: R0_w=invP(id=0) R6_w=invP(id=0) R10=fp0
  3: (57) r6 &= 808464432
  4: R0_w=invP(id=0) R6_w=invP(id=0,umax_value=808464432,var_off=(0x0; 0x30303030)) R10=fp0
  4: (14) w6 -= 810299440
  5: R0_w=invP(id=0) R6_w=invP(id=0,umax_value=4294967295,var_off=(0xcf800000; 0x3077fff0)) R10=fp0
  5: (c4) w6 s>>= 1
  6: R0_w=invP(id=0) R6_w=invP(id=0,umin_value=3888119808,umax_value=4294705144,var_off=(0xe7c00000; 0x183bfff8)) R10=fp0
                                              (0x67c00000)          (0xfffbfff8)
  6: (76) if w6 s>= 0x30303030 goto pc+216
  7: R0_w=invP(id=0) R6_w=invP(id=0,umin_value=3888119808,umax_value=4294705144,var_off=(0xe7c00000; 0x183bfff8)) R10=fp0
  7: (30) r0 = *(u8 *)skb[808464432]
  BPF_LD_[ABS|IND] uses reserved fields
  processed 8 insns (limit 1000000) [...]

Fixes: 9cbe1f5a32 ("bpf/verifier: improve register value range tracking with ARSH")
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115204733.16648-1-daniel@iogearbox.net
2020-01-15 13:39:59 -08:00
Chunyan Zhang
5167c506d6 tick/common: Touch watchdog in tick_unfreeze() on all CPUs
Suspend to IDLE invokes tick_unfreeze() on resume. tick_unfreeze() on the
first resuming CPU resumes timekeeping, which also has the side effect of
resetting the softlockup watchdog on this CPU.

But on the secondary CPUs the watchdog is not reset in the resume /
unfreeze() path, which can result in false softlockup warnings on those
CPUs depending on the time spent in suspend.

Prevent this by clearing the softlock watchdog in the unfreeze path also
on the secondary resuming CPUs.

[ tglx: Massaged changelog ]

Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200110083902.27276-1-chunyan.zhang@unisoc.com
2020-01-15 21:29:45 +01:00
Yonghong Song
8482941f09 bpf: Add bpf_send_signal_thread() helper
Commit 8b401f9ed2 ("bpf: implement bpf_send_signal() helper")
added helper bpf_send_signal() which permits bpf program to
send a signal to the current process. The signal may be
delivered to any threads in the process.

We found a use case where sending the signal to the current
thread is more preferable.
  - A bpf program will collect the stack trace and then
    send signal to the user application.
  - The user application will add some thread specific
    information to the just collected stack trace for
    later analysis.

If bpf_send_signal() is used, user application will need
to check whether the thread receiving the signal matches
the thread collecting the stack by checking thread id.
If not, it will need to send signal to another thread
through pthread_kill().

This patch proposed a new helper bpf_send_signal_thread(),
which sends the signal to the thread corresponding to
the current kernel task. This way, user space is guaranteed that
bpf_program execution context and user space signal handling
context are the same thread.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115035002.602336-1-yhs@fb.com
2020-01-15 11:44:51 -08:00
Michal Koutný
3bc0bb36fa cgroup: Prevent double killing of css when enabling threaded cgroup
The test_cgcore_no_internal_process_constraint_on_threads selftest when
running with subsystem controlling noise triggers two warnings:

> [  597.443115] WARNING: CPU: 1 PID: 28167 at kernel/cgroup/cgroup.c:3131 cgroup_apply_control_enable+0xe0/0x3f0
> [  597.443413] WARNING: CPU: 1 PID: 28167 at kernel/cgroup/cgroup.c:3177 cgroup_apply_control_disable+0xa6/0x160

Both stem from a call to cgroup_type_write. The first warning was also
triggered by syzkaller.

When we're switching cgroup to threaded mode shortly after a subsystem
was disabled on it, we can see the respective subsystem css dying there.

The warning in cgroup_apply_control_enable is harmless in this case
since we're not adding new subsys anyway.
The warning in cgroup_apply_control_disable indicates an attempt to kill
css of recently disabled subsystem repeatedly.

The commit prevents these situations by making cgroup_type_write wait
for all dying csses to go away before re-applying subtree controls.
When at it, the locations of WARN_ON_ONCE calls are moved so that
warning is triggered only when we are about to misuse the dying css.

Reported-by: syzbot+5493b2a54d31d6aea629@syzkaller.appspotmail.com
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-01-15 08:04:29 -08:00
Daniel Jordan
1c5da0ec7f workqueue: add worker function to workqueue_execute_end tracepoint
It's surprising that workqueue_execute_end includes only the work when
its counterpart workqueue_execute_start has both the work and the worker
function.

You can't set a tracing filter or trigger based on the function, and
postprocessing scripts interested in specific functions are harder to
write since they have to remember the work from _start and match it up
with the same field in _end.

Add the function name, taking care to use the copy stashed in the
worker since the work is no longer safe to touch.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-01-15 08:02:47 -08:00
Chen Zhou
75ea91cd3e cgroup: fix function name in comment
Function name cgroup_rstat_cpu_pop_upated() in comment should be
cgroup_rstat_cpu_pop_updated().

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-01-15 07:58:13 -08:00
Jessica Yu
e9f35f634e modsign: print module name along with error message
It is useful to know which module failed signature verification, so
print the module name along with the error message.

Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-01-15 15:49:31 +01:00