Commit Graph

1378 Commits

Author SHA1 Message Date
John Stultz
5311c740c0 UPSTREAM: time: Clean up CLOCK_MONOTONIC_RAW time handling
(cherry pick from commit fc6eead7c1)

Now that we fixed the sub-ns handling for CLOCK_MONOTONIC_RAW,
remove the duplicitive tk->raw_time.tv_nsec, which can be
stored in tk->tkr_raw.xtime_nsec (similarly to how its handled
for monotonic time).

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Daniel Mentz <danielmentz@google.com>
Tested-by: Daniel Mentz <danielmentz@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Bug: 20045882
Bug: 63737556
Change-Id: I243827d21b08703a09d2d2fe738a9258be224582
2017-11-29 13:44:16 -08:00
Greg Kroah-Hartman
f108c7d9b5 Merge 4.9.58 into android-4.9
Changes in 4.9.58
	MIPS: Fix minimum alignment requirement of IRQ stack
	Revert "bsg-lib: don't free job in bsg_prepare_job"
	xen-netback: Use GFP_ATOMIC to allocate hash
	locking/lockdep: Add nest_lock integrity test
	watchdog: kempld: fix gcc-4.3 build
	irqchip/crossbar: Fix incorrect type of local variables
	initramfs: finish fput() before accessing any binary from initramfs
	mac80211_hwsim: check HWSIM_ATTR_RADIO_NAME length
	ALSA: hda: Add Geminilake HDMI codec ID
	qed: Don't use attention PTT for configuring BW
	mac80211: fix power saving clients handling in iwlwifi
	net/mlx4_en: fix overflow in mlx4_en_init_timestamp()
	staging: vchiq_2835_arm: Make cache-line-size a required DT property
	netfilter: nf_ct_expect: Change __nf_ct_expect_check() return value.
	iio: adc: xilinx: Fix error handling
	f2fs: do SSR for data when there is enough free space
	sched/fair: Update rq clock before changing a task's CPU affinity
	Btrfs: send, fix failure to rename top level inode due to name collision
	f2fs: do not wait for writeback in write_begin
	md/linear: shutup lockdep warnning
	sparc64: Migrate hvcons irq to panicked cpu
	net/mlx4_core: Fix VF overwrite of module param which disables DMFS on new probed PFs
	crypto: xts - Add ECB dependency
	mm/memory_hotplug: set magic number to page->freelist instead of page->lru.next
	ocfs2/dlmglue: prepare tracking logic to avoid recursive cluster lock
	slub: do not merge cache if slub_debug contains a never-merge flag
	scsi: scsi_dh_emc: return success in clariion_std_inquiry()
	ASoC: mediatek: add I2C dependency for CS42XX8
	drm/amdgpu: refuse to reserve io mem for split VRAM buffers
	net: mvpp2: release reference to txq_cpu[] entry after unmapping
	qede: Prevent index problems in loopback test
	qed: Reserve doorbell BAR space for present CPUs
	qed: Read queue state before releasing buffer
	i2c: at91: ensure state is restored after suspending
	ceph: don't update_dentry_lease unless we actually got one
	ceph: fix bogus endianness change in ceph_ioctl_set_layout
	ceph: clean up unsafe d_parent accesses in build_dentry_path
	uapi: fix linux/rds.h userspace compilation errors
	uapi: fix linux/mroute6.h userspace compilation errors
	IB/hfi1: Use static CTLE with Preset 6 for integrated HFIs
	IB/hfi1: Allocate context data on memory node
	target/iscsi: Fix unsolicited data seq_end_offset calculation
	hrtimer: Catch invalid clockids again
	nfsd/callback: Cleanup callback cred on shutdown
	powerpc/perf: Add restrictions to PMC5 in power9 DD1
	drm/nouveau/gr/gf100-: fix ccache error logging
	regulator: core: Resolve supplies before disabling unused regulators
	btmrvl: avoid double-disable_irq() race
	EDAC, mce_amd: Print IPID and Syndrome on a separate line
	cpufreq: CPPC: add ACPI_PROCESSOR dependency
	usb: dwc3: gadget: Correct ISOC DATA PIDs for short packets
	Linux 4.9.58

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2017-10-23 09:35:27 +02:00
Marc Zyngier
0c92e73293 hrtimer: Catch invalid clockids again
[ Upstream commit 336a9cde10 ]

commit 82e88ff1ea ("hrtimer: Revert CLOCK_MONOTONIC_RAW support") removed
unfortunately a sanity check in the hrtimer code which was part of that
MONOTONIC_RAW patch series.

It would have caught the bogus usage of CLOCK_MONOTONIC_RAW in the wireless
code. So bring it back.

It is way too easy to take any random clockid and feed it to the hrtimer
subsystem. At best, it gets mapped to a monotonic base, but it would be
better to just catch illegal values as early as possible.

Detect invalid clockids, map them to CLOCK_MONOTONIC and emit a warning.

[ tglx: Replaced the BUG by a WARN and gracefully map to CLOCK_MONOTONIC ]

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Tomasz Nowicki <tn@semihalf.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Link: http://lkml.kernel.org/r/1452879670-16133-3-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-21 17:21:38 +02:00
Greg Kroah-Hartman
379e3b2a6d Merge 4.9.53 into android-4.9
Changes in 4.9.53
	cifs: release cifs root_cred after exit_cifs
	cifs: release auth_key.response for reconnect.
	fs/proc: Report eip/esp in /prod/PID/stat for coredumping
	mac80211: fix VLAN handling with TXQs
	mac80211_hwsim: Use proper TX power
	mac80211: flush hw_roc_start work before cancelling the ROC
	genirq: Make sparse_irq_lock protect what it should protect
	KVM: PPC: Book3S: Fix race and leak in kvm_vm_ioctl_create_spapr_tce()
	KVM: PPC: Book3S HV: Protect updates to spapr_tce_tables list
	tracing: Fix trace_pipe behavior for instance traces
	tracing: Erase irqsoff trace with empty write
	md/raid5: fix a race condition in stripe batch
	md/raid5: preserve STRIPE_ON_UNPLUG_LIST in break_stripe_batch_list
	scsi: scsi_transport_iscsi: fix the issue that iscsi_if_rx doesn't parse nlmsg properly
	drm/radeon: disable hard reset in hibernate for APUs
	crypto: drbg - fix freeing of resources
	crypto: talitos - Don't provide setkey for non hmac hashing algs.
	crypto: talitos - fix sha224
	crypto: talitos - fix hashing
	security/keys: properly zero out sensitive key material in big_key
	security/keys: rewrite all of big_key crypto
	KEYS: fix writing past end of user-supplied buffer in keyring_read()
	KEYS: prevent creating a different user's keyrings
	KEYS: prevent KEYCTL_READ on negative key
	powerpc/pseries: Fix parent_dn reference leak in add_dt_node()
	powerpc/tm: Flush TM only if CPU has TM feature
	powerpc/ftrace: Pass the correct stack pointer for DYNAMIC_FTRACE_WITH_REGS
	s390/mm: fix write access check in gup_huge_pmd()
	PM: core: Fix device_pm_check_callbacks()
	Fix SMB3.1.1 guest authentication to Samba
	SMB3: Warn user if trying to sign connection that authenticated as guest
	SMB: Validate negotiate (to protect against downgrade) even if signing off
	SMB3: Don't ignore O_SYNC/O_DSYNC and O_DIRECT flags
	vfs: Return -ENXIO for negative SEEK_HOLE / SEEK_DATA offsets
	nl80211: check for the required netlink attributes presence
	bsg-lib: don't free job in bsg_prepare_job
	iw_cxgb4: remove the stid on listen create failure
	iw_cxgb4: put ep reference in pass_accept_req()
	selftests/seccomp: Support glibc 2.26 siginfo_t.h
	seccomp: fix the usage of get/put_seccomp_filter() in seccomp_get_filter()
	arm64: Make sure SPsel is always set
	arm64: fault: Route pte translation faults via do_translation_fault
	KVM: VMX: extract __pi_post_block
	KVM: VMX: avoid double list add with VT-d posted interrupts
	KVM: VMX: simplify and fix vmx_vcpu_pi_load
	kvm/x86: Handle async PF in RCU read-side critical sections
	KVM: VMX: Do not BUG() on out-of-bounds guest IRQ
	kvm: nVMX: Don't allow L2 to access the hardware CR8
	xfs: validate bdev support for DAX inode flag
	etnaviv: fix gem object list corruption
	PCI: Fix race condition with driver_override
	btrfs: fix NULL pointer dereference from free_reloc_roots()
	btrfs: propagate error to btrfs_cmp_data_prepare caller
	btrfs: prevent to set invalid default subvolid
	x86/mm: Fix fault error path using unsafe vma pointer
	x86/fpu: Don't let userspace set bogus xcomp_bv
	gfs2: Fix debugfs glocks dump
	timer/sysclt: Restrict timer migration sysctl values to 0 and 1
	KVM: VMX: do not change SN bit in vmx_update_pi_irte()
	KVM: VMX: remove WARN_ON_ONCE in kvm_vcpu_trigger_posted_interrupt
	cxl: Fix driver use count
	KVM: VMX: use cmpxchg64
	video: fbdev: aty: do not leak uninitialized padding in clk to userspace
	swiotlb-xen: implement xen_swiotlb_dma_mmap callback
	Linux 4.9.53

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2017-10-05 10:37:37 +02:00
Myungho Jung
4c00015385 timer/sysclt: Restrict timer migration sysctl values to 0 and 1
commit b94bf594cf upstream.

timer_migration sysctl acts as a boolean switch, so the allowed values
should be restricted to 0 and 1.

Add the necessary extra fields to the sysctl table entry to enforce that.

[ tglx: Rewrote changelog ]

Signed-off-by: Myungho Jung <mhjungk@gmail.com>
Link: http://lkml.kernel.org/r/1492640690-3550-1-git-send-email-mhjungk@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kazuhiro Hayashi <kazuhiro3.hayashi@toshiba.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-05 09:44:04 +02:00
Greg Kroah-Hartman
a3840b1234 Merge 4.9.46 into android-4.9
Changes in 4.9.46
	sparc64: remove unnecessary log message
	af_key: do not use GFP_KERNEL in atomic contexts
	dccp: purge write queue in dccp_destroy_sock()
	dccp: defer ccid_hc_tx_delete() at dismantle time
	ipv4: fix NULL dereference in free_fib_info_rcu()
	net_sched/sfq: update hierarchical backlog when drop packet
	net_sched: remove warning from qdisc_hash_add
	bpf: fix bpf_trace_printk on 32 bit archs
	openvswitch: fix skb_panic due to the incorrect actions attrlen
	ptr_ring: use kmalloc_array()
	ipv4: better IP_MAX_MTU enforcement
	nfp: fix infinite loop on umapping cleanup
	sctp: fully initialize the IPv6 address in sctp_v6_to_addr()
	tipc: fix use-after-free
	ipv6: reset fn->rr_ptr when replacing route
	ipv6: repair fib6 tree in failure case
	tcp: when rearming RTO, if RTO time is in past then fire RTO ASAP
	net/mlx4_core: Enable 4K UAR if SRIOV module parameter is not enabled
	irda: do not leak initialized list.dev to userspace
	net: sched: fix NULL pointer dereference when action calls some targets
	net_sched: fix order of queue length updates in qdisc_replace()
	bpf, verifier: add additional patterns to evaluate_reg_imm_alu
	bpf: adjust verifier heuristics
	bpf, verifier: fix alu ops against map_value{, _adj} register types
	bpf: fix mixed signed/unsigned derived min/max value bounds
	bpf/verifier: fix min/max handling in BPF_SUB
	Input: trackpoint - add new trackpoint firmware ID
	Input: elan_i2c - add ELAN0602 ACPI ID to support Lenovo Yoga310
	Input: ALPS - fix two-finger scroll breakage in right side on ALPS touchpad
	KVM: s390: sthyi: fix sthyi inline assembly
	KVM: s390: sthyi: fix specification exception detection
	KVM: x86: block guest protection keys unless the host has them enabled
	ALSA: usb-audio: Add delay quirk for H650e/Jabra 550a USB headsets
	ALSA: core: Fix unexpected error at replacing user TLV
	ALSA: hda - Add stereo mic quirk for Lenovo G50-70 (17aa:3978)
	ALSA: firewire: fix NULL pointer dereference when releasing uninitialized data of iso-resource
	ARCv2: PAE40: Explicitly set MSB counterpart of SLC region ops addresses
	mm, shmem: fix handling /sys/kernel/mm/transparent_hugepage/shmem_enabled
	i2c: designware: Fix system suspend
	mm/madvise.c: fix freeing of locked page with MADV_FREE
	fork: fix incorrect fput of ->exe_file causing use-after-free
	mm/memblock.c: reversed logic in memblock_discard()
	drm: Release driver tracking before making the object available again
	drm/atomic: If the atomic check fails, return its value first
	drm: rcar-du: Fix crash in encoder failure error path
	drm: rcar-du: Fix display timing controller parameter
	drm: rcar-du: Fix H/V sync signal polarity configuration
	tracing: Call clear_boot_tracer() at lateinit_sync
	tracing: Fix kmemleak in tracing_map_array_free()
	tracing: Fix freeing of filter in create_filter() when set_str is false
	kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured
	cifs: Fix df output for users with quota limits
	cifs: return ENAMETOOLONG for overlong names in cifs_open()/cifs_lookup()
	nfsd: Limit end of page list when decoding NFSv4 WRITE
	ftrace: Check for null ret_stack on profile function graph entry function
	perf/core: Fix group {cpu,task} validation
	perf probe: Fix --funcs to show correct symbols for offline module
	perf/x86/intel/rapl: Make package handling more robust
	timers: Fix excessive granularity of new timers after a nohz idle
	x86/mm: Fix use-after-free of ldt_struct
	net: sunrpc: svcsock: fix NULL-pointer exception
	Revert "leds: handle suspend/resume in heartbeat trigger"
	netfilter: nat: fix src map lookup
	Bluetooth: hidp: fix possible might sleep error in hidp_session_thread
	Bluetooth: cmtp: fix possible might sleep error in cmtp_session
	Bluetooth: bnep: fix possible might sleep error in bnep_session
	Revert "android: binder: Sanity check at binder ioctl"
	binder: use group leader instead of open thread
	binder: Use wake up hint for synchronous transactions.
	ANDROID: binder: fix proc->tsk check.
	iio: imu: adis16480: Fix acceleration scale factor for adis16480
	iio: hid-sensor-trigger: Fix the race with user space powering up sensors
	staging: rtl8188eu: add RNX-N150NUB support
	Clarify (and fix) MAX_LFS_FILESIZE macros
	ntb_transport: fix qp count bug
	ntb_transport: fix bug calculating num_qps_mw
	NTB: ntb_test: fix bug printing ntb_perf results
	ntb: no sleep in ntb_async_tx_submit
	ntb: ntb_test: ensure the link is up before trying to configure the mws
	ntb: transport shouldn't disable link due to bogus values in SPADs
	ACPI: ioapic: Clear on-stack resource before using it
	ACPI / APEI: Add missing synchronize_rcu() on NOTIFY_SCI removal
	ACPI: EC: Fix regression related to wrong ECDT initialization order
	powerpc/mm: Ensure cpumask update is ordered
	Linux 4.9.46

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2017-08-30 15:24:10 +02:00
Nicholas Piggin
70b3fd5ce2 timers: Fix excessive granularity of new timers after a nohz idle
commit 2fe59f507a upstream.

When a timer base is idle, it is forwarded when a new timer is added
to ensure that granularity does not become excessive. When not idle,
the timer tick is expected to increment the base.

However there are several problems:

- If an existing timer is modified, the base is forwarded only after
  the index is calculated.

- The base is not forwarded by add_timer_on.

- There is a window after a timer is restarted from a nohz idle, after
  it is marked not-idle and before the timer tick on this CPU, where a
  timer may be added but the ancient base does not get forwarded.

These result in excessive granularity (a 1 jiffy timeout can blow out
to 100s of jiffies), which cause the rcu lockup detector to trigger,
among other things.

Fix this by keeping track of whether the timer base has been idle
since it was last run or forwarded, and if so then forward it before
adding a new timer.

There is still a case where mod_timer optimises the case of a pending
timer mod with the same expiry time, where the timer can see excessive
granularity relative to the new, shorter interval. A comment is added,
but it's not changed because it is an important fastpath for
networking.

This has been tested and found to fix the RCU softlockup messages.

Testing was also done with tracing to measure requested versus
achieved wakeup latencies for all non-deferrable timers in an idle
system (with no lockup watchdogs running). Wakeup latency relative to
absolute latency is calculated (note this suffers from round-up skew
at low absolute times) and analysed:

             max     avg      std
upstream   506.0    1.20     4.68
patched      2.0    1.08     0.15

The bug was noticed due to the lockup detector Kconfig changes
dropping it out of people's .configs and resulting in larger base
clk skew When the lockup detectors are enabled, no CPU can go idle for
longer than 4 seconds, which limits the granularity errors.
Sub-optimal timer behaviour is observable on a smaller scale in that
case:

	     max     avg      std
upstream     9.0    1.05     0.19
patched      2.0    1.04     0.11

Fixes: Fixes: a683f390b9 ("timers: Forward the wheel clock whenever possible")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: David Miller <davem@davemloft.net>
Cc: dzickus@redhat.com
Cc: sfr@canb.auug.org.au
Cc: mpe@ellerman.id.au
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: linuxarm@huawei.com
Cc: abdhalee@linux.vnet.ibm.com
Cc: John Stultz <john.stultz@linaro.org>
Cc: akpm@linux-foundation.org
Cc: paulmck@linux.vnet.ibm.com
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/20170822084348.21436-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-30 10:21:51 +02:00
Greg Kroah-Hartman
02f29ab1b9 Merge 4.9.42 into android-4.9
Changes in 4.9.42
	parisc: Handle vma's whose context is not current in flush_cache_range
	cgroup: create dfl_root files on subsys registration
	cgroup: fix error return value from cgroup_subtree_control()
	libata: array underflow in ata_find_dev()
	workqueue: restore WQ_UNBOUND/max_active==1 to be ordered
	iwlwifi: dvm: prevent an out of bounds access
	brcmfmac: fix memleak due to calling brcmf_sdiod_sgtable_alloc() twice
	NFSv4: Fix EXCHANGE_ID corrupt verifier issue
	mmc: sdhci-of-at91: force card detect value for non removable devices
	device property: Make dev_fwnode() public
	mmc: core: Fix access to HS400-ES devices
	mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries
	cpuset: fix a deadlock due to incomplete patching of cpusets_enabled()
	ALSA: hda - Fix speaker output from VAIO VPCL14M1R
	drm/amdgpu: Fix undue fallthroughs in golden registers initialization
	ASoC: do not close shared backend dailink
	KVM: async_pf: make rcu irq exit if not triggered from idle task
	mm/page_alloc: Remove kernel address exposure in free_reserved_area()
	timers: Fix overflow in get_next_timer_interrupt
	powerpc/tm: Fix saving of TM SPRs in core dump
	powerpc/64: Fix __check_irq_replay missing decrementer interrupt
	iommu/amd: Enable ga_log_intr when enabling guest_mode
	gpiolib: skip unwanted events, don't convert them to opposite edge
	ext4: fix SEEK_HOLE/SEEK_DATA for blocksize < pagesize
	ext4: fix overflow caused by missing cast in ext4_resize_fs()
	ARM: dts: armada-38x: Fix irq type for pca955
	ARM: dts: tango4: Request RGMII RX and TX clock delays
	media: platform: davinci: return -EINVAL for VPFE_CMD_S_CCDC_RAW_PARAMS ioctl
	iscsi-target: Fix initial login PDU asynchronous socket close OOPs
	mmc: dw_mmc: Use device_property_read instead of of_property_read
	mmc: core: Use device_property_read instead of of_property_read
	media: lirc: LIRC_GET_REC_RESOLUTION should return microseconds
	f2fs: sanity check checkpoint segno and blkoff
	Btrfs: fix early ENOSPC due to delalloc
	saa7164: fix double fetch PCIe access condition
	tcp_bbr: cut pacing rate only if filled pipe
	tcp_bbr: introduce bbr_bw_to_pacing_rate() helper
	tcp_bbr: introduce bbr_init_pacing_rate_from_rtt() helper
	tcp_bbr: remove sk_pacing_rate=0 transient during init
	tcp_bbr: init pacing rate on first RTT sample
	ipv4: ipv6: initialize treq->txhash in cookie_v[46]_check()
	net: Zero terminate ifr_name in dev_ifname().
	ipv6: avoid overflow of offset in ip6_find_1stfragopt
	net: dsa: b53: Add missing ARL entries for BCM53125
	ipv4: initialize fib_trie prior to register_netdev_notifier call.
	rtnetlink: allocate more memory for dev_set_mac_address()
	mcs7780: Fix initialization when CONFIG_VMAP_STACK is enabled
	openvswitch: fix potential out of bound access in parse_ct
	packet: fix use-after-free in prb_retire_rx_blk_timer_expired()
	ipv6: Don't increase IPSTATS_MIB_FRAGFAILS twice in ip6_fragment()
	net: ethernet: nb8800: Handle all 4 RGMII modes identically
	dccp: fix a memleak that dccp_ipv6 doesn't put reqsk properly
	dccp: fix a memleak that dccp_ipv4 doesn't put reqsk properly
	dccp: fix a memleak for dccp_feat_init err process
	sctp: don't dereference ptr before leaving _sctp_walk_{params, errors}()
	sctp: fix the check for _sctp_walk_params and _sctp_walk_errors
	net/mlx5: Consider tx_enabled in all modes on remap
	net/mlx5: Fix command bad flow on command entry allocation failure
	net/mlx5e: Fix outer_header_zero() check size
	net/mlx5e: Fix wrong delay calculation for overflow check scheduling
	net/mlx5e: Schedule overflow check work to mlx5e workqueue
	net: phy: Correctly process PHY_HALTED in phy_stop_machine()
	xen-netback: correctly schedule rate-limited queues
	sparc64: Measure receiver forward progress to avoid send mondo timeout
	sparc64: Fix exception handling in UltraSPARC-III memcpy.
	wext: handle NULL extra data in iwe_stream_add_point better
	sh_eth: fix EESIPR values for SH77{34|63}
	sh_eth: R8A7740 supports packet shecksumming
	net: phy: dp83867: fix irq generation
	tg3: Fix race condition in tg3_get_stats64().
	x86/boot: Add missing declaration of string functions
	spi: spi-axi: Free resources on error path
	ASoC: rt5645: set sel_i2s_pre_div1 to 2
	netfilter: use fwmark_reflect in nf_send_reset
	phy state machine: failsafe leave invalid RUNNING state
	ipv4: make tcp_notsent_lowat sysctl knob behave as true unsigned int
	clk/samsung: exynos542x: mark some clocks as critical
	scsi: qla2xxx: Get mutex lock before checking optrom_state
	drm/virtio: fix framebuffer sparse warning
	ARM: dts: sun8i: Support DTB build for NanoPi M1
	ARM: dts: sunxi: Change node name for pwrseq pin on Olinuxino-lime2-emmc
	iw_cxgb4: do not send RX_DATA_ACK CPLs after close/abort
	nbd: blk_mq_init_queue returns an error code on failure, not NULL
	virtio_blk: fix panic in initialization error path
	ARM: 8632/1: ftrace: fix syscall name matching
	mm, slab: make sure that KMALLOC_MAX_SIZE will fit into MAX_ORDER
	lib/Kconfig.debug: fix frv build failure
	signal: protect SIGNAL_UNKILLABLE from unintentional clearing.
	mm: don't dereference struct page fields of invalid pages
	net/mlx5: E-Switch, Re-enable RoCE on mode change only after FDB destroy
	ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output
	net: account for current skb length when deciding about UFO
	net: phy: Fix PHY unbind crash
	workqueue: implicit ordered attribute should be overridable
	Linux 4.9.42

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2017-08-11 13:55:02 -07:00
Matija Glavinic Pecotic
9ef8b23b94 timers: Fix overflow in get_next_timer_interrupt
commit 34f41c0316 upstream.

For e.g. HZ=100, timer being 430 jiffies in the future, and 32 bit
unsigned int, there is an overflow on unsigned int right-hand side
of the expression which results with wrong values being returned.

Type cast the multiplier to 64bit to avoid that issue.

Fixes: 46c8f0b077 ("timers: Fix get_next_timer_interrupt() computation")
Signed-off-by: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Cc: khilman@baylibre.com
Cc: akpm@linux-foundation.org
Link: http://lkml.kernel.org/r/a7900f04-2a21-c9fd-67be-ab334d459ee5@nokia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-11 08:49:30 -07:00
Chris Redpath
595ae4adc5 UPSTREAM: cpufreq: schedutil: Avoid reducing frequency of busy CPUs prematurely
The way the schedutil governor uses the PELT metric causes it to
underestimate the CPU utilization in some cases.

That can be easily demonstrated by running kernel compilation on
a Sandy Bridge Intel processor, running turbostat in parallel with
it and looking at the values written to the MSR_IA32_PERF_CTL
register.  Namely, the expected result would be that when all CPUs
were 100% busy, all of them would be requested to run in the maximum
P-state, but observation shows that this clearly isn't the case.
The CPUs run in the maximum P-state for a while and then are
requested to run slower and go back to the maximum P-state after
a while again.  That causes the actual frequency of the processor to
visibly oscillate below the sustainable maximum in a jittery fashion
which clearly is not desirable.

That has been attributed to CPU utilization metric updates on task
migration that cause the total utilization value for the CPU to be
reduced by the utilization of the migrated task.  If that happens,
the schedutil governor may see a CPU utilization reduction and will
attempt to reduce the CPU frequency accordingly right away.  That
may be premature, though, for example if the system is generally
busy and there are other runnable tasks waiting to be run on that
CPU already.

This is unlikely to be an issue on systems where cpufreq policies are
shared between multiple CPUs, because in those cases the policy
utilization is computed as the maximum of the CPU utilization values
over the whole policy and if that turns out to be low, reducing the
frequency for the policy most likely is a good idea anyway.  On
systems with one CPU per policy, however, it may affect performance
adversely and even lead to increased energy consumption in some cases.

On those systems it may be addressed by taking another utilization
metric into consideration, like whether or not the CPU whose
frequency is about to be reduced has been idle recently, because if
that's not the case, the CPU is likely to be busy in the near future
and its frequency should not be reduced.

To that end, use the counter of idle calls in the timekeeping code.
Namely, make the schedutil governor look at that counter for the
current CPU every time before its frequency is about to be reduced.
If the counter has not changed since the previous iteration of the
governor computations for that CPU, the CPU has been busy for all
that time and its frequency should not be decreased, so if the new
frequency would be lower than the one set previously, the governor
will skip the frequency update.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Joel Fernandes <joelaf@google.com>
(cherry picked from commit b7eaf1aab9)
(simple CPUFREQ_RT_DL vs CPUFREQ_DL usage conflicts)
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Change-Id: I531ec02c052944ee07a904dc2a25c59948ee762b
Signed-off-by: Quentin Perret <quentin.perret@arm.com>
2017-08-03 15:30:48 -07:00
Greg Kroah-Hartman
9ae2c670d8 Merge 4.9.40 into android-4.9
Changes in 4.9.40
	disable new gcc-7.1.1 warnings for now
	ir-core: fix gcc-7 warning on bool arithmetic
	dm mpath: cleanup -Wbool-operation warning in choose_pgpath()
	s5p-jpeg: don't return a random width/height
	thermal: max77620: fix device-node reference imbalance
	thermal: cpu_cooling: Avoid accessing potentially freed structures
	ath9k: fix tx99 use after free
	ath9k: fix tx99 bus error
	ath9k: fix an invalid pointer dereference in ath9k_rng_stop()
	NFC: fix broken device allocation
	NFC: nfcmrvl_uart: add missing tty-device sanity check
	NFC: nfcmrvl: do not use device-managed resources
	NFC: nfcmrvl: use nfc-device for firmware download
	NFC: nfcmrvl: fix firmware-management initialisation
	nfc: Ensure presence of required attributes in the activate_target handler
	nfc: Fix the sockaddr length sanitization in llcp_sock_connect
	NFC: Add sockaddr length checks before accessing sa_family in bind handlers
	perf intel-pt: Move decoder error setting into one condition
	perf intel-pt: Improve sample timestamp
	perf intel-pt: Fix missing stack clear
	perf intel-pt: Ensure IP is zero when state is INTEL_PT_STATE_NO_IP
	perf intel-pt: Fix last_ip usage
	perf intel-pt: Ensure never to set 'last_ip' when packet 'count' is zero
	perf intel-pt: Use FUP always when scanning for an IP
	perf intel-pt: Clear FUP flag on error
	Bluetooth: use constant time memory comparison for secret values
	wlcore: fix 64K page support
	btrfs: Don't clear SGID when inheriting ACLs
	igb: Explicitly select page 0 at initialization
	ASoC: compress: Derive substream from stream based on direction
	PM / Domains: Fix unsafe iteration over modified list of device links
	PM / Domains: Fix unsafe iteration over modified list of domain providers
	PM / Domains: Fix unsafe iteration over modified list of domains
	scsi: ses: do not add a device to an enclosure if enclosure_add_links() fails.
	scsi: Add STARGET_CREATED_REMOVE state to scsi_target_state
	iscsi-target: Add login_keys_workaround attribute for non RFC initiators
	xen/scsiback: Fix a TMR related use-after-free
	powerpc/pseries: Fix passing of pp0 in updatepp() and updateboltedpp()
	powerpc/64: Fix atomic64_inc_not_zero() to return an int
	powerpc: Fix emulation of mcrf in emulate_step()
	powerpc: Fix emulation of mfocrf in emulate_step()
	powerpc/asm: Mark cr0 as clobbered in mftb()
	powerpc/mm/radix: Properly clear process table entry
	af_key: Fix sadb_x_ipsecrequest parsing
	PCI: Work around poweroff & suspend-to-RAM issue on Macbook Pro 11
	PCI: rockchip: Use normal register bank for config accessors
	PCI/PM: Restore the status of PCI devices across hibernation
	ipvs: SNAT packet replies only for NATed connections
	xhci: fix 20000ms port resume timeout
	xhci: Fix NULL pointer dereference when cleaning up streams for removed host
	xhci: Bad Ethernet performance plugged in ASM1042A host
	mxl111sf: Fix driver to use heap allocate buffers for USB messages
	usb: storage: return on error to avoid a null pointer dereference
	USB: cdc-acm: add device-id for quirky printer
	usb: renesas_usbhs: fix usbhsc_resume() for !USBHSF_RUNTIME_PWCTRL
	usb: renesas_usbhs: gadget: disable all eps when the driver stops
	md: don't use flush_signals in userspace processes
	x86/xen: allow userspace access during hypercalls
	cx88: Fix regression in initial video standard setting
	libnvdimm, btt: fix btt_rw_page not returning errors
	libnvdimm: fix badblock range handling of ARS range
	ext2: Don't clear SGID when inheriting ACLs
	Raid5 should update rdev->sectors after reshape
	s390/syscalls: Fix out of bounds arguments access
	drm/amd/amdgpu: Return error if initiating read out of range on vram
	drm/radeon/ci: disable mclk switching for high refresh rates (v2)
	drm/radeon: Fix eDP for single-display iMac10,1 (v2)
	ipmi: use rcu lock around call to intf->handlers->sender()
	ipmi:ssif: Add missing unlock in error branch
	xfs: Don't clear SGID when inheriting ACLs
	f2fs: sanity check size of nat and sit cache
	f2fs: Don't clear SGID when inheriting ACLs
	drm/ttm: Fix use-after-free in ttm_bo_clean_mm
	ovl: drop CAP_SYS_RESOURCE from saved mounter's credentials
	vfio: Fix group release deadlock
	vfio: New external user group/file match
	nvme-rdma: remove race conditions from IB signalling
	ftrace: Fix uninitialized variable in match_records()
	MIPS: Fix mips_atomic_set() retry condition
	MIPS: Fix mips_atomic_set() with EVA
	MIPS: Negate error syscall return in trace
	ubifs: Don't leak kernel memory to the MTD
	ACPI / EC: Drop EC noirq hooks to fix a regression
	Revert "ACPI / EC: Enable event freeze mode..." to fix a regression
	x86/acpi: Prevent out of bound access caused by broken ACPI tables
	x86/ioapic: Pass the correct data to unmask_ioapic_irq()
	MIPS: Fix MIPS I ISA /proc/cpuinfo reporting
	MIPS: Save static registers before sysmips
	MIPS: Actually decode JALX in `__compute_return_epc_for_insn'
	MIPS: Fix unaligned PC interpretation in `compute_return_epc'
	MIPS: math-emu: Prevent wrong ISA mode instruction emulation
	MIPS: Send SIGILL for BPOSGE32 in `__compute_return_epc_for_insn'
	MIPS: Rename `sigill_r6' to `sigill_r2r6' in `__compute_return_epc_for_insn'
	MIPS: Send SIGILL for linked branches in `__compute_return_epc_for_insn'
	MIPS: Send SIGILL for R6 branches in `__compute_return_epc_for_insn'
	MIPS: Fix a typo: s/preset/present/ in r2-to-r6 emulation error message
	Input: i8042 - fix crash at boot time
	IB/iser: Fix connection teardown race condition
	IB/core: Namespace is mandatory input for address resolution
	sunrpc: use constant time memory comparison for mac
	NFS: only invalidate dentrys that are clearly invalid.
	udf: Fix deadlock between writeback and udf_setsize()
	target: Fix COMPARE_AND_WRITE caw_sem leak during se_cmd quiesce
	iser-target: Avoid isert_conn->cm_id dereference in isert_login_recv_done
	perf annotate: Fix broken arrow at row 0 connecting jmp instruction to its target
	Revert "perf/core: Drop kernel samples even though :u is specified"
	staging: rtl8188eu: add TL-WN722N v2 support
	staging: comedi: ni_mio_common: fix AO timer off-by-one regression
	staging: sm750fb: avoid conflicting vesafb
	staging: lustre: ko2iblnd: check copy_from_iter/copy_to_iter return code
	ceph: fix race in concurrent readdir
	RDMA/core: Initialize port_num in qp_attr
	drm/mst: Fix error handling during MST sideband message reception
	drm/mst: Avoid dereferencing a NULL mstb in drm_dp_mst_handle_up_req()
	drm/mst: Avoid processing partially received up/down message transactions
	mlx5: Avoid that mlx5_ib_sg_to_klms() overflows the klms[] array
	hfsplus: Don't clear SGID when inheriting ACLs
	ovl: fix random return value on mount
	acpi/nfit: Fix memory corruption/Unregister mce decoder on failure
	of: device: Export of_device_{get_modalias, uvent_modalias} to modules
	spmi: Include OF based modalias in device uevent
	reiserfs: Don't clear SGID when inheriting ACLs
	PM / Domains: defer dev_pm_domain_set() until genpd->attach_dev succeeds if present
	tracing: Fix kmemleak in instance_rmdir
	alarmtimer: don't rate limit one-shot timers
	Linux 4.9.40

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2017-07-27 15:24:43 -07:00
Greg Hackmann
91af5f04cd alarmtimer: don't rate limit one-shot timers
Commit ff86bf0c65 ("alarmtimer: Rate limit periodic intervals") sets a
minimum bound on the alarm timer interval.  This minimum bound shouldn't
be applied if the interval is 0.  Otherwise, one-shot timers will be
converted into periodic ones.

Fixes: ff86bf0c65 ("alarmtimer: Rate limit periodic intervals")
Reported-by: Ben Fennema <fennema@google.com>
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Cc: stable@vger.kernel.org
Cc: John Stultz <john.stultz@linaro.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27 15:08:08 -07:00
Greg Kroah-Hartman
75d78c7eda Merge 4.9.35 into android-4.9
Changes in 4.9.35
	clk: sunxi-ng: a31: Correct lcd1-ch1 clock register offset
	xen/blkback: fix disconnect while I/Os in flight
	xen-blkback: don't leak stack data via response ring
	ALSA: firewire-lib: Fix stall of process context at packet error
	ALSA: pcm: Don't treat NULL chmap as a fatal error
	fs/exec.c: account for argv/envp pointers
	powerpc/perf: Fix oops when kthread execs user process
	autofs: sanity check status reported with AUTOFS_DEV_IOCTL_FAIL
	lib/cmdline.c: fix get_options() overflow while parsing ranges
	perf/x86/intel: Add 1G DTLB load/store miss support for SKL
	KVM: s390: gaccess: fix real-space designation asce handling for gmap shadows
	KVM: PPC: Book3S HV: Preserve userspace HTM state properly
	KVM: PPC: Book3S HV: Context-switch EBB registers properly
	CIFS: Improve readdir verbosity
	cxgb4: notify uP to route ctrlq compl to rdma rspq
	HID: Add quirk for Dell PIXART OEM mouse
	signal: Only reschedule timers on signals timers have sent
	powerpc/kprobes: Pause function_graph tracing during jprobes handling
	powerpc/64s: Handle data breakpoints in Radix mode
	Input: i8042 - add Fujitsu Lifebook AH544 to notimeout list
	brcmfmac: add parameter to pass error code in firmware callback
	brcmfmac: use firmware callback upon failure to load
	brcmfmac: unbind all devices upon failure in firmware callback
	time: Fix clock->read(clock) race around clocksource changes
	time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting
	arm64/vdso: Fix nsec handling for CLOCK_MONOTONIC_RAW
	target: Fix kref->refcount underflow in transport_cmd_finish_abort
	iscsi-target: Fix delayed logout processing greater than SECONDS_FOR_LOGOUT_COMP
	iscsi-target: Reject immediate data underflow larger than SCSI transfer length
	drm/radeon: add a PX quirk for another K53TK variant
	drm/radeon: add a quirk for Toshiba Satellite L20-183
	drm/amdgpu/atom: fix ps allocation size for EnableDispPowerGating
	drm/amdgpu: adjust default display clock
	rxrpc: Fix several cases where a padded len isn't checked in ticket decode
	of: Add check to of_scan_flat_dt() before accessing initial_boot_params
	mtd: spi-nor: fix spansion quad enable
	usb: gadget: f_fs: avoid out of bounds access on comp_desc
	rt2x00: avoid introducing a USB dependency in the rt2x00lib module
	net: phy: Initialize mdio clock at probe function
	dmaengine: bcm2835: Fix cyclic DMA period splitting
	spi: double time out tolerance
	net: phy: fix marvell phy status reading
	jump label: fix passing kbuild_cflags when checking for asm goto support
	brcmfmac: fix uninitialized warning in brcmf_usb_probe_phase2()
	Linux 4.9.35

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2017-06-29 14:26:07 +02:00
John Stultz
a53bfdda06 time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting
commit 3d88d56c58 upstream.

Due to how the MONOTONIC_RAW accumulation logic was handled,
there is the potential for a 1ns discontinuity when we do
accumulations. This small discontinuity has for the most part
gone un-noticed, but since ARM64 enabled CLOCK_MONOTONIC_RAW
in their vDSO clock_gettime implementation, we've seen failures
with the inconsistency-check test in kselftest.

This patch addresses the issue by using the same sub-ns
accumulation handling that CLOCK_MONOTONIC uses, which avoids
the issue for in-kernel users.

Since the ARM64 vDSO implementation has its own clock_gettime
calculation logic, this patch reduces the frequency of errors,
but failures are still seen. The ARM64 vDSO will need to be
updated to include the sub-nanosecond xtime_nsec values in its
calculation for this issue to be completely fixed.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Daniel Mentz <danielmentz@google.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Link: http://lkml.kernel.org/r/1496965462-20003-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-29 13:00:30 +02:00
John Stultz
02a37ccd63 time: Fix clock->read(clock) race around clocksource changes
commit ceea5e3771 upstream.

In tests, which excercise switching of clocksources, a NULL
pointer dereference can be observed on AMR64 platforms in the
clocksource read() function:

u64 clocksource_mmio_readl_down(struct clocksource *c)
{
	return ~(u64)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
}

This is called from the core timekeeping code via:

	cycle_now = tkr->read(tkr->clock);

tkr->read is the cached tkr->clock->read() function pointer.
When the clocksource is changed then tkr->clock and tkr->read
are updated sequentially. The code above results in a sequential
load operation of tkr->read and tkr->clock as well.

If the store to tkr->clock hits between the loads of tkr->read
and tkr->clock, then the old read() function is called with the
new clock pointer. As a consequence the read() function
dereferences a different data structure and the resulting 'reg'
pointer can point anywhere including NULL.

This problem was introduced when the timekeeping code was
switched over to use struct tk_read_base. Before that, it was
theoretically possible as well when the compiler decided to
reload clock in the code sequence:

     now = tk->clock->read(tk->clock);

Add a helper function which avoids the issue by reading
tk_read_base->clock once into a local variable clk and then issue
the read function via clk->read(clk). This guarantees that the
read() function always gets the proper clocksource pointer handed
in.

Since there is now no use for the tkr.read pointer, this patch
also removes it, and to address stopping the fast timekeeper
during suspend/resume, it introduces a dummy clocksource to use
rather then just a dummy read function.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Daniel Mentz <danielmentz@google.com>
Link: http://lkml.kernel.org/r/1496965462-20003-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-29 13:00:30 +02:00
Greg Kroah-Hartman
7172a93a70 Merge 4.9.34 into android-4.9
Changes in 4.9.34
	fs: pass on flags in compat_writev
	configfs: Fix race between create_link and configfs_rmdir
	can: gs_usb: fix memory leak in gs_cmd_reset()
	ila_xlat: add missing hash secret initialization
	cpufreq: conservative: Allow down_threshold to take values from 1 to 10
	vb2: Fix an off by one error in 'vb2_plane_vaddr'
	mac80211: don't look at the PM bit of BAR frames
	mac80211/wpa: use constant time memory comparison for MACs
	drm/amdgpu: Fix overflow of watermark calcs at > 4k resolutions.
	drm/i915: Fix GVT-g PVINFO version compatibility check
	usb: musb: dsps: keep VBUS on for host-only mode
	mac80211: fix CSA in IBSS mode
	mac80211: fix packet statistics for fast-RX
	mac80211: fix IBSS presp allocation size
	mac80211: strictly check mesh address extension mode
	mac80211: fix dropped counter in multiqueue RX
	mac80211: don't send SMPS action frame in AP mode when not needed
	drm/mediatek: fix mtk_hdmi_setup_vendor_specific_infoframe mistake
	drm/vc4: Fix OOPSes from trying to cache a partially constructed BO.
	serial: efm32: Fix parity management in 'efm32_uart_console_get_options()'
	serial: sh-sci: Fix late enablement of AUTORTS
	x86/mm/32: Set the '__vmalloc_start_set' flag in initmem_init()
	mfd: omap-usb-tll: Fix inverted bit use for USB TLL mode
	staging: rtl8188eu: prevent an underflow in rtw_check_beacon_data()
	staging: iio: tsl2x7x_core: Fix standard deviation calculation
	iio: st_pressure: Fix data sign
	iio: proximity: as3935: recalibrate RCO after resume
	iio: adc: ti_am335x_adc: allocating too much in probe
	IB/mlx5: Fix kernel to user leak prevention logic
	usb: gadget: udc: renesas_usb3: fix pm_runtime functions calling
	usb: gadget: udc: renesas_usb3: fix deadlock by spinlock
	usb: gadget: udc: renesas_usb3: lock for PN_ registers access
	USB: hub: fix SS max number of ports
	usb: core: fix potential memory leak in error path during hcd creation
	USB: usbip: fix nonconforming hub descriptor
	pvrusb2: reduce stack usage pvr2_eeprom_analyze()
	USB: gadget: dummy_hcd: fix hub-descriptor removable fields
	usb: r8a66597-hcd: select a different endpoint on timeout
	usb: r8a66597-hcd: decrease timeout
	ath10k: fix napi crash during rmmod when probe firmware fails
	misc: mic: double free on ioctl error path
	drivers/misc/c2port/c2port-duramar2150.c: checking for NULL instead of IS_ERR()
	usb: xhci: Fix USB 3.1 supported protocol parsing
	usb: xhci: ASMedia ASM1042A chipset need shorts TX quirk
	USB: gadget: fix GPF in gadgetfs
	USB: gadgetfs, dummy-hcd, net2280: fix locking for callbacks
	mm/memory-failure.c: use compound_head() flags for huge pages
	swap: cond_resched in swap_cgroup_prepare()
	iio: imu: inv_mpu6050: add accel lpf setting for chip >= MPU6500
	sched/core: Idle_task_exit() shouldn't use switch_mm_irqs_off()
	genirq: Release resources in __setup_irq() error path
	alarmtimer: Prevent overflow of relative timers
	usb: gadget: composite: Fix function used to free memory
	usb: dwc3: exynos fix axius clock error path to do cleanup
	MIPS: Fix bnezc/jialc return address calculation
	MIPS: .its targets depend on vmlinux
	vTPM: Fix missing NULL check
	crypto: Work around deallocated stack frame reference gcc bug on sparc.
	alarmtimer: Rate limit periodic intervals
	mm: larger stack guard gap, between vmas
	Allow stack to grow up to address space limit
	mm: fix new crash in unmapped_area_topdown()
	Linux 4.9.34

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2017-06-27 10:43:56 +02:00
Thomas Gleixner
04651048c7 alarmtimer: Rate limit periodic intervals
commit ff86bf0c65 upstream.

The alarmtimer code has another source of potentially rearming itself too
fast. Interval timers with a very samll interval have a similar CPU hog
effect as the previously fixed overflow issue.

The reason is that alarmtimers do not implement the normal protection
against this kind of problem which the other posix timer use:

  timer expires -> queue signal -> deliver signal -> rearm timer

This scheme brings the rearming under scheduler control and prevents
permanently firing timers which hog the CPU.

Bringing this scheme to the alarm timer code is a major overhaul because it
lacks all the necessary mechanisms completely.

So for a quick fix limit the interval to one jiffie. This is not
problematic in practice as alarmtimers are usually backed by an RTC for
suspend which have 1 second resolution. It could be therefor argued that
the resolution of this clock should be set to 1 second in general, but
that's outside the scope of this fix.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kostya Serebryany <kcc@google.com>
Cc: syzkaller <syzkaller@googlegroups.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Link: http://lkml.kernel.org/r/20170530211655.896767100@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-24 07:11:17 +02:00
Thomas Gleixner
8ee7f06f4d alarmtimer: Prevent overflow of relative timers
commit f4781e76f9 upstream.

Andrey reported a alartimer related RCU stall while fuzzing the kernel with
syzkaller.

The reason for this is an overflow in ktime_add() which brings the
resulting time into negative space and causes immediate expiry of the
timer. The following rearm with a small interval does not bring the timer
back into positive space due to the same issue.

This results in a permanent firing alarmtimer which hogs the CPU.

Use ktime_add_safe() instead which detects the overflow and clamps the
result to KTIME_SEC_MAX.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kostya Serebryany <kcc@google.com>
Cc: syzkaller <syzkaller@googlegroups.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Link: http://lkml.kernel.org/r/20170530211655.802921648@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-24 07:11:17 +02:00
Todd Kjos
0455ac9d3c Merge branch 'upstream-linux-4.9.y' into android-4.9 2017-02-23 14:29:44 -08:00
Sergey Senozhatsky
215d4d62cc timekeeping: Use deferred printk() in debug code
commit f222449c9d upstream.

We cannot do printk() from tk_debug_account_sleep_time(), because
tk_debug_account_sleep_time() is called under tk_core seq lock.
The reason why printk() is unsafe there is that console_sem may
invoke scheduler (up()->wake_up_process()->activate_task()), which,
in turn, can return back to timekeeping code, for instance, via
get_time()->ktime_get(), deadlocking the system on tk_core seq lock.

[   48.950592] ======================================================
[   48.950622] [ INFO: possible circular locking dependency detected ]
[   48.950622] 4.10.0-rc7-next-20170213+ #101 Not tainted
[   48.950622] -------------------------------------------------------
[   48.950622] kworker/0:0/3 is trying to acquire lock:
[   48.950653]  (tk_core){----..}, at: [<c01cc624>] retrigger_next_event+0x4c/0x90
[   48.950683]
               but task is already holding lock:
[   48.950683]  (hrtimer_bases.lock){-.-...}, at: [<c01cc610>] retrigger_next_event+0x38/0x90
[   48.950714]
               which lock already depends on the new lock.

[   48.950714]
               the existing dependency chain (in reverse order) is:
[   48.950714]
               -> #5 (hrtimer_bases.lock){-.-...}:
[   48.950744]        _raw_spin_lock_irqsave+0x50/0x64
[   48.950775]        lock_hrtimer_base+0x28/0x58
[   48.950775]        hrtimer_start_range_ns+0x20/0x5c8
[   48.950775]        __enqueue_rt_entity+0x320/0x360
[   48.950805]        enqueue_rt_entity+0x2c/0x44
[   48.950805]        enqueue_task_rt+0x24/0x94
[   48.950836]        ttwu_do_activate+0x54/0xc0
[   48.950836]        try_to_wake_up+0x248/0x5c8
[   48.950836]        __setup_irq+0x420/0x5f0
[   48.950836]        request_threaded_irq+0xdc/0x184
[   48.950866]        devm_request_threaded_irq+0x58/0xa4
[   48.950866]        omap_i2c_probe+0x530/0x6a0
[   48.950897]        platform_drv_probe+0x50/0xb0
[   48.950897]        driver_probe_device+0x1f8/0x2cc
[   48.950897]        __driver_attach+0xc0/0xc4
[   48.950927]        bus_for_each_dev+0x6c/0xa0
[   48.950927]        bus_add_driver+0x100/0x210
[   48.950927]        driver_register+0x78/0xf4
[   48.950958]        do_one_initcall+0x3c/0x16c
[   48.950958]        kernel_init_freeable+0x20c/0x2d8
[   48.950958]        kernel_init+0x8/0x110
[   48.950988]        ret_from_fork+0x14/0x24
[   48.950988]
               -> #4 (&rt_b->rt_runtime_lock){-.-...}:
[   48.951019]        _raw_spin_lock+0x40/0x50
[   48.951019]        rq_offline_rt+0x9c/0x2bc
[   48.951019]        set_rq_offline.part.2+0x2c/0x58
[   48.951049]        rq_attach_root+0x134/0x144
[   48.951049]        cpu_attach_domain+0x18c/0x6f4
[   48.951049]        build_sched_domains+0xba4/0xd80
[   48.951080]        sched_init_smp+0x68/0x10c
[   48.951080]        kernel_init_freeable+0x160/0x2d8
[   48.951080]        kernel_init+0x8/0x110
[   48.951080]        ret_from_fork+0x14/0x24
[   48.951110]
               -> #3 (&rq->lock){-.-.-.}:
[   48.951110]        _raw_spin_lock+0x40/0x50
[   48.951141]        task_fork_fair+0x30/0x124
[   48.951141]        sched_fork+0x194/0x2e0
[   48.951141]        copy_process.part.5+0x448/0x1a20
[   48.951171]        _do_fork+0x98/0x7e8
[   48.951171]        kernel_thread+0x2c/0x34
[   48.951171]        rest_init+0x1c/0x18c
[   48.951202]        start_kernel+0x35c/0x3d4
[   48.951202]        0x8000807c
[   48.951202]
               -> #2 (&p->pi_lock){-.-.-.}:
[   48.951232]        _raw_spin_lock_irqsave+0x50/0x64
[   48.951232]        try_to_wake_up+0x30/0x5c8
[   48.951232]        up+0x4c/0x60
[   48.951263]        __up_console_sem+0x2c/0x58
[   48.951263]        console_unlock+0x3b4/0x650
[   48.951263]        vprintk_emit+0x270/0x474
[   48.951293]        vprintk_default+0x20/0x28
[   48.951293]        printk+0x20/0x30
[   48.951324]        kauditd_hold_skb+0x94/0xb8
[   48.951324]        kauditd_thread+0x1a4/0x56c
[   48.951324]        kthread+0x104/0x148
[   48.951354]        ret_from_fork+0x14/0x24
[   48.951354]
               -> #1 ((console_sem).lock){-.....}:
[   48.951385]        _raw_spin_lock_irqsave+0x50/0x64
[   48.951385]        down_trylock+0xc/0x2c
[   48.951385]        __down_trylock_console_sem+0x24/0x80
[   48.951385]        console_trylock+0x10/0x8c
[   48.951416]        vprintk_emit+0x264/0x474
[   48.951416]        vprintk_default+0x20/0x28
[   48.951416]        printk+0x20/0x30
[   48.951446]        tk_debug_account_sleep_time+0x5c/0x70
[   48.951446]        __timekeeping_inject_sleeptime.constprop.3+0x170/0x1a0
[   48.951446]        timekeeping_resume+0x218/0x23c
[   48.951477]        syscore_resume+0x94/0x42c
[   48.951477]        suspend_enter+0x554/0x9b4
[   48.951477]        suspend_devices_and_enter+0xd8/0x4b4
[   48.951507]        enter_state+0x934/0xbd4
[   48.951507]        pm_suspend+0x14/0x70
[   48.951507]        state_store+0x68/0xc8
[   48.951538]        kernfs_fop_write+0xf4/0x1f8
[   48.951538]        __vfs_write+0x1c/0x114
[   48.951538]        vfs_write+0xa0/0x168
[   48.951568]        SyS_write+0x3c/0x90
[   48.951568]        __sys_trace_return+0x0/0x10
[   48.951568]
               -> #0 (tk_core){----..}:
[   48.951599]        lock_acquire+0xe0/0x294
[   48.951599]        ktime_get_update_offsets_now+0x5c/0x1d4
[   48.951629]        retrigger_next_event+0x4c/0x90
[   48.951629]        on_each_cpu+0x40/0x7c
[   48.951629]        clock_was_set_work+0x14/0x20
[   48.951660]        process_one_work+0x2b4/0x808
[   48.951660]        worker_thread+0x3c/0x550
[   48.951660]        kthread+0x104/0x148
[   48.951690]        ret_from_fork+0x14/0x24
[   48.951690]
               other info that might help us debug this:

[   48.951690] Chain exists of:
                 tk_core --> &rt_b->rt_runtime_lock --> hrtimer_bases.lock

[   48.951721]  Possible unsafe locking scenario:

[   48.951721]        CPU0                    CPU1
[   48.951721]        ----                    ----
[   48.951721]   lock(hrtimer_bases.lock);
[   48.951751]                                lock(&rt_b->rt_runtime_lock);
[   48.951751]                                lock(hrtimer_bases.lock);
[   48.951751]   lock(tk_core);
[   48.951782]
                *** DEADLOCK ***

[   48.951782] 3 locks held by kworker/0:0/3:
[   48.951782]  #0:  ("events"){.+.+.+}, at: [<c0156590>] process_one_work+0x1f8/0x808
[   48.951812]  #1:  (hrtimer_work){+.+...}, at: [<c0156590>] process_one_work+0x1f8/0x808
[   48.951843]  #2:  (hrtimer_bases.lock){-.-...}, at: [<c01cc610>] retrigger_next_event+0x38/0x90
[   48.951843]   stack backtrace:
[   48.951873] CPU: 0 PID: 3 Comm: kworker/0:0 Not tainted 4.10.0-rc7-next-20170213+
[   48.951904] Workqueue: events clock_was_set_work
[   48.951904] [<c0110208>] (unwind_backtrace) from [<c010c224>] (show_stack+0x10/0x14)
[   48.951934] [<c010c224>] (show_stack) from [<c04ca6c0>] (dump_stack+0xac/0xe0)
[   48.951934] [<c04ca6c0>] (dump_stack) from [<c019b5cc>] (print_circular_bug+0x1d0/0x308)
[   48.951965] [<c019b5cc>] (print_circular_bug) from [<c019d2a8>] (validate_chain+0xf50/0x1324)
[   48.951965] [<c019d2a8>] (validate_chain) from [<c019ec18>] (__lock_acquire+0x468/0x7e8)
[   48.951995] [<c019ec18>] (__lock_acquire) from [<c019f634>] (lock_acquire+0xe0/0x294)
[   48.951995] [<c019f634>] (lock_acquire) from [<c01d0ea0>] (ktime_get_update_offsets_now+0x5c/0x1d4)
[   48.952026] [<c01d0ea0>] (ktime_get_update_offsets_now) from [<c01cc624>] (retrigger_next_event+0x4c/0x90)
[   48.952026] [<c01cc624>] (retrigger_next_event) from [<c01e4e24>] (on_each_cpu+0x40/0x7c)
[   48.952056] [<c01e4e24>] (on_each_cpu) from [<c01cafc4>] (clock_was_set_work+0x14/0x20)
[   48.952056] [<c01cafc4>] (clock_was_set_work) from [<c015664c>] (process_one_work+0x2b4/0x808)
[   48.952087] [<c015664c>] (process_one_work) from [<c0157774>] (worker_thread+0x3c/0x550)
[   48.952087] [<c0157774>] (worker_thread) from [<c015d644>] (kthread+0x104/0x148)
[   48.952087] [<c015d644>] (kthread) from [<c0107830>] (ret_from_fork+0x14/0x24)

Replace printk() with printk_deferred(), which does not call into
the scheduler.

Fixes: 0bf43f15db ("timekeeping: Prints the amounts of time spent during suspend")
Reported-and-tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170215044332.30449-1-sergey.senozhatsky@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-23 17:44:36 +01:00
Dmitry Shmidt
cd08287396 Merge tag 'v4.9.6' into android-4.9
This is the 4.9.6 stable release

Change-Id: I318df4b9d706d50c13fe3969d734117c25fc94bc
2017-01-31 13:55:27 -08:00
Joel Fernandes
72408a6328 UPSTREAM: timekeeping: Add a fast and NMI safe boot clock
This boot clock can be used as a tracing clock and will account for
suspend time.

To keep it NMI safe since we're accessing from tracing, we're not using a
separate timekeeper with updates to monotonic clock and boot offset
protected with seqlocks. This has the following minor side effects:

(1) Its possible that a timestamp be taken after the boot offset is updated
but before the timekeeper is updated. If this happens, the new boot offset
is added to the old timekeeping making the clock appear to update slightly
earlier:
   CPU 0                                        CPU 1
   timekeeping_inject_sleeptime64()
   __timekeeping_inject_sleeptime(tk, delta);
                                                timestamp();
   timekeeping_update(tk, TK_CLEAR_NTP...);

(2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be
partially updated.  Since the tk->offs_boot update is a rare event, this
should be a rare occurrence which postprocessing should be able to handle.

Bug: b/33184060

Change-Id: If79be2ed9d7a25ac39805b1fd81743026fc96575
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-01-27 13:55:47 -08:00
Thomas Gleixner
cf365b1173 tick/broadcast: Prevent NULL pointer dereference
commit c1a9eeb938 upstream.

When a disfunctional timer, e.g. dummy timer, is installed, the tick core
tries to setup the broadcast timer.

If no broadcast device is installed, the kernel crashes with a NULL pointer
dereference in tick_broadcast_setup_oneshot() because the function has no
sanity check.

Reported-by: Mason <slash.tmp@free.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Richard Cochran <rcochran@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Cc: Sebastian Frias <sf84@laposte.net>
Cc: Thibaud Cornic <thibaud_cornic@sigmadesigns.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Link: http://lkml.kernel.org/r/1147ef90-7877-e4d2-bb2b-5c4fa8d3144b@free.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-12 11:39:45 +01:00
Thomas Gleixner
ca22975afa timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversion
commit 9c1645727b upstream.

The clocksource delta to nanoseconds conversion is using signed math, but
the delta is unsigned. This makes the conversion space smaller than
necessary and in case of a multiplication overflow the conversion can
become negative. The conversion is done with scaled math:

    s64 nsec_delta = ((s64)clkdelta * clk->mult) >> clk->shift;

Shifting a signed integer right obvioulsy preserves the sign, which has
interesting consequences:

 - Time jumps backwards

 - __iter_div_u64_rem() which is used in one of the calling code pathes
   will take forever to piecewise calculate the seconds/nanoseconds part.

This has been reported by several people with different scenarios:

David observed that when stopping a VM with a debugger:

 "It was essentially the stopped by debugger case.  I forget exactly why,
  but the guest was being explicitly stopped from outside, it wasn't just
  scheduling lag.  I think it was something in the vicinity of 10 minutes
  stopped."

 When lifting the stop the machine went dead.

The stopped by debugger case is not really interesting, but nevertheless it
would be a good thing not to die completely.

But this was also observed on a live system by Liav:

 "When the OS is too overloaded, delta will get a high enough value for the
  msb of the sum delta * tkr->mult + tkr->xtime_nsec to be set, and so
  after the shift the nsec variable will gain a value similar to
  0xffffffffff000000."

Unfortunately this has been reintroduced recently with commit 6bd58f09e1
("time: Add cycles to nanoseconds translation"). It had been fixed a year
ago already in commit 35a4933a89 ("time: Avoid signed overflow in
timekeeping_get_ns()").

Though it's not surprising that the issue has been reintroduced because the
function itself and the whole call chain uses s64 for the result and the
propagation of it. The change in this recent commit is subtle:

   s64 nsec;

-  nsec = (d * m + n) >> s:
+  nsec = d * m + n;
+  nsec >>= s;

d being type of cycle_t adds another level of obfuscation.

This wouldn't have happened if the previous change to unsigned computation
would have made the 'nsec' variable u64 right away and a follow up patch
had cleaned up the whole call chain.

There have been patches submitted which basically did a revert of the above
patch leaving everything else unchanged as signed. Back to square one. This
spawned a admittedly pointless discussion about potential users which rely
on the unsigned behaviour until someone pointed out that it had been fixed
before. The changelogs of said patches added further confusion as they made
finally false claims about the consequences for eventual users which expect
signed results.

Despite delta being cycle_t, aka. u64, it's very well possible to hand in
a signed negative value and the signed computation will happily return the
correct result. But nobody actually sat down and analyzed the code which
was added as user after the propably unintended signed conversion.

Though in sensitive code like this it's better to analyze it proper and
make sure that nothing relies on this than hunting the subtle wreckage half
a year later. After analyzing all call chains it stands that no caller can
hand in a negative value (which actually would work due to the s64 cast)
and rely on the signed math to do the right thing.

Change the conversion function to unsigned math. The conversion of all call
chains is done in a follow up patch.

This solves the starvation issue, which was caused by the negative result,
but it does not solve the underlying problem. It merily procrastinates
it. When the timekeeper update is deferred long enough that the unsigned
multiplication overflows, then time going backwards is observable again.

It does neither solve the issue of clocksources with a small counter width
which will wrap around possibly several times and cause random time stamps
to be generated. But those are usually not found on systems used for
virtualization, so this is likely a non issue.

I took the liberty to claim authorship for this simply because
analyzing all callsites and writing the changelog took substantially
more time than just making the simple s/s64/u64/ change and ignore the
rest.

Fixes: 6bd58f09e1 ("time: Add cycles to nanoseconds translation")
Reported-by: David Gibson <david@gibson.dropbear.id.au>
Reported-by: Liav Rehana <liavr@mellanox.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Parit Bhargava <prarit@redhat.com>
Cc: Laurent Vivier <lvivier@redhat.com>
Cc: "Christopher S. Hall" <christopher.s.hall@intel.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20161208204228.688545601@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-09 08:32:17 +01:00
Thomas Gleixner
6bad6bccf2 timers: Prevent base clock corruption when forwarding
When a timer is enqueued we try to forward the timer base clock. This
mechanism has two issues:

1) Forwarding a remote base unlocked

The forwarding function is called from get_target_base() with the current
timer base lock held. But if the new target base is a different base than
the current base (can happen with NOHZ, sigh!) then the forwarding is done
on an unlocked base. This can lead to corruption of base->clk.

Solution is simple: Invoke the forwarding after the target base is locked.

2) Possible corruption due to jiffies advancing

This is similar to the issue in get_net_timer_interrupt() which was fixed
in the previous patch. jiffies can advance between check and assignement
and therefore advancing base->clk beyond the next expiry value.

So we need to read jiffies into a local variable once and do the checks and
assignment with the local copy.

Fixes: a683f390b93f("timers: Forward the wheel clock whenever possible")
Reported-by: Ashton Holmes <scoopta@gmail.com>
Reported-by: Michael Thayer <michael.thayer@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Michal Necasek <michal.necasek@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: knut.osmundsen@oracle.com
Cc: stable@vger.kernel.org
Cc: stern@rowland.harvard.edu
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161022110552.253640125@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-25 16:32:50 +02:00
Thomas Gleixner
041ad7bc75 timers: Prevent base clock rewind when forwarding clock
Ashton and Michael reported, that kernel versions 4.8 and later suffer from
USB timeouts which are caused by the timer wheel rework.

This is caused by a bug in the base clock forwarding mechanism, which leads
to timers expiring early. The scenario which leads to this is:

run_timers()
  while (jiffies >= base->clk) {
    collect_expired_timers();
    base->clk++;
    expire_timers();
  }          

So base->clk = jiffies + 1. Now the cpu goes idle:

idle()
  get_next_timer_interrupt()
    nextevt = __next_time_interrupt();
    if (time_after(nextevt, base->clk))
       	base->clk = jiffies;

jiffies has not advanced since run_timers(), so this assignment effectively
decrements base->clk by one.

base->clk is the index into the timer wheel arrays. So let's assume the
following state after the base->clk increment in run_timers():

 jiffies = 0
 base->clk = 1

A timer gets enqueued with an expiry delta of 63 ticks (which is the case
with the USB timeout and HZ=250) so the resulting bucket index is:

  base->clk + delta = 1 + 63 = 64

The timer goes into the first wheel level. The array size is 64 so it ends
up in bucket 0, which is correct as it takes 63 ticks to advance base->clk
to index into bucket 0 again.

If the cpu goes idle before jiffies advance, then the bug in the forwarding
mechanism sets base->clk back to 0, so the next invocation of run_timers()
at the next tick will index into bucket 0 and therefore expire the timer 62
ticks too early.

Instead of blindly setting base->clk to jiffies we must make the forwarding
conditional on jiffies > base->clk, but we cannot use jiffies for this as
we might run into the following issue:

  if (time_after(jiffies, base->clk) {
    if (time_after(nextevt, base->clk))
       base->clk = jiffies;

jiffies can increment between the check and the assigment far enough to
advance beyond nextevt. So we need to use a stable value for checking.

get_next_timer_interrupt() has the basej argument which is the jiffies
value snapshot taken in the calling code. So we can just that.

Thanks to Ashton for bisecting and providing trace data!

Fixes: a683f390b9 ("timers: Forward the wheel clock whenever possible")
Reported-by: Ashton Holmes <scoopta@gmail.com>
Reported-by: Michael Thayer <michael.thayer@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Michal Necasek <michal.necasek@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: knut.osmundsen@oracle.com
Cc: stable@vger.kernel.org
Cc: stern@rowland.harvard.edu
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161022110552.175308322@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-25 16:32:50 +02:00
Thomas Gleixner
4da9152a43 timers: Lock base for same bucket optimization
Linus stumbled over the unlocked modification of the timer expiry value in
mod_timer() which is an optimization for timers which stay in the same
bucket - due to the bucket granularity - despite their expiry time getting
updated.

The optimization itself still makes sense even if we take the lock, because
in case that the bucket stays the same, we avoid the pointless
queue/enqueue dance.

Make the check and the modification of timer->expires protected by the base
lock and shuffle the remaining code around so we can keep the lock held
when we actually have to requeue the timer to a different bucket.

Fixes: f00c0afdfa ("timers: Implement optimization for same expiry time in mod_timer()")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1610241711220.4983@nanos
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
2016-10-25 16:27:39 +02:00
Thomas Gleixner
b831275a35 timers: Plug locking race vs. timer migration
Linus noticed that lock_timer_base() lacks a READ_ONCE() for accessing the
timer flags. As a consequence the compiler is allowed to reload the flags
between the initial check for TIMER_MIGRATION and the following timer base
computation and the spin lock of the base.

While this has not been observed (yet), we need to make sure that it never
happens.

Fixes: 0eeda71bc3 ("timer: Replace timer base by a cpu index")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1610241711220.4983@nanos
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
2016-10-25 16:27:39 +02:00
Tobias Klauser
54e23845e9 alarmtimer: Remove unused but set variable
Remove the set but unused variable base in alarm_clock_get to fix the
following warning when building with 'W=1':

  kernel/time/alarmtimer.c: In function ‘alarm_timer_create’:
  kernel/time/alarmtimer.c:545:21: warning: variable ‘base’ set but not used [-Wunused-but-set-variable]

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20161017094702.10873-1-tklauser@distanz.ch
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-17 11:59:37 +02:00
Linus Torvalds
9ffc66941d Merge tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull gcc plugins update from Kees Cook:
 "This adds a new gcc plugin named "latent_entropy". It is designed to
  extract as much possible uncertainty from a running system at boot
  time as possible, hoping to capitalize on any possible variation in
  CPU operation (due to runtime data differences, hardware differences,
  SMP ordering, thermal timing variation, cache behavior, etc).

  At the very least, this plugin is a much more comprehensive example
  for how to manipulate kernel code using the gcc plugin internals"

* tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  latent_entropy: Mark functions with __latent_entropy
  gcc-plugins: Add latent_entropy plugin
2016-10-15 10:03:15 -07:00
Emese Revfy
0766f788eb latent_entropy: Mark functions with __latent_entropy
The __latent_entropy gcc attribute can be used only on functions and
variables.  If it is on a function then the plugin will instrument it for
gathering control-flow entropy. If the attribute is on a variable then
the plugin will initialize it with random contents.  The variable must
be an integer, an integer array type or a structure with integer fields.

These specific functions have been selected because they are init
functions (to help gather boot-time entropy), are called at unpredictable
times, or they have variable loops, each of which provide some level of
latent entropy.

Signed-off-by: Emese Revfy <re.emese@gmail.com>
[kees: expanded commit message]
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-10-10 14:51:45 -07:00
John Stultz
58bfea9532 timekeeping: Fix __ktime_get_fast_ns() regression
In commit 27727df240 ("Avoid taking lock in NMI path with
CONFIG_DEBUG_TIMEKEEPING"), I changed the logic to open-code
the timekeeping_get_ns() function, but I forgot to include
the unit conversion from cycles to nanoseconds, breaking the
function's output, which impacts users like perf.

This results in bogus perf timestamps like:
 swapper     0 [000]   253.427536:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.426573:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.426687:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.426800:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.426905:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427022:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427127:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427239:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427346:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   254.427463:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]   255.426572:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])

Instead of more reasonable expected timestamps like:
 swapper     0 [000]    39.953768:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.064839:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.175956:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.287103:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.398217:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.509324:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.620437:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.731546:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.842654:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    40.953772:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])
 swapper     0 [000]    41.064881:  111111111 cpu-clock:  ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms])

Add the proper use of timekeeping_delta_to_ns() to convert
the cycle delta to nanoseconds as needed.

Thanks to Brendan and Alexei for finding this quickly after
the v4.8 release. Unfortunately the problematic commit has
landed in some -stable trees so they'll need this fix as
well.

Many apologies for this mistake. I'll be looking to add a
perf-clock sanity test to the kselftest timers tests soon.

Fixes: 27727df240 "timekeeping: Avoid taking lock in NMI path with CONFIG_DEBUG_TIMEKEEPING"
Reported-by: Brendan Gregg <bgregg@netflix.com>
Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Tested-and-reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable <stable@vger.kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1475636148-26539-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-05 15:44:46 +02:00
Wanpeng Li
57ccdf449f tick/nohz: Prevent stopping the tick on an offline CPU
can_stop_full_tick() has no check for offline cpus. So it allows to stop
the tick on an offline cpu from the interrupt return path, which is wrong
and subsequently makes irq_work_needs_cpu() warn about being called for an
offline cpu.

Commit f7ea0fd639 ("tick: Don't invoke tick_nohz_stop_sched_tick() if
the cpu is offline") added prevention for can_stop_idle_tick(), but forgot
to do the same in can_stop_full_tick(). Add it.

[ tglx: Massaged changelog ]

Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1473245473-4463-1-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-13 17:53:52 +02:00
Ingo Molnar
950d8381d9 Merge branch 'linus' into timers/core, to refresh the branch
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-08 14:05:16 +02:00
Wanpeng Li
08d0725992 tick/nohz: Fix softlockup on scheduler stalls in kvm guest
tick_nohz_start_idle() is prevented to be called if the idle tick can't 
be stopped since commit 1f3b0f8243 ("tick/nohz: Optimize nohz idle 
enter"). As a result, after suspend/resume the host machine, full dynticks 
kvm guest will softlockup:

 NMI watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [swapper/0:0]
 Call Trace:
  default_idle+0x31/0x1a0
  arch_cpu_idle+0xf/0x20
  default_idle_call+0x2a/0x50
  cpu_startup_entry+0x39b/0x4d0
  rest_init+0x138/0x140
  ? rest_init+0x5/0x140
  start_kernel+0x4c1/0x4ce
  ? set_init_arg+0x55/0x55
  ? early_idt_handler_array+0x120/0x120
  x86_64_start_reservations+0x24/0x26
  x86_64_start_kernel+0x142/0x14f

In addition, cat /proc/stat | grep cpu in guest or host:

cpu  398 16 5049 15754 5490 0 1 46 0 0
cpu0 206 5 450 0 0 0 1 14 0 0
cpu1 81 0 3937 3149 1514 0 0 9 0 0
cpu2 45 6 332 6052 2243 0 0 11 0 0
cpu3 65 2 328 6552 1732 0 0 11 0 0

The idle and iowait states are weird 0 for cpu0(housekeeping). 

The bug is present in both guest and host kernels, and they both have 
cpu0's idle and iowait states issue, however, host kernel's suspend/resume 
path etc will touch watchdog to avoid the softlockup.

- The watchdog will not be touched in tick_nohz_stop_idle path (need be 
  touched since the scheduler stall is expected) if idle_active flags are 
  not detected.
- The idle and iowait states will not be accounted when exit idle loop 
  (resched or interrupt) if idle start time and idle_active flags are 
  not set. 

This patch fixes it by reverting commit 1f3b0f8243 since can't stop 
idle tick doesn't mean can't be idle.

Fixes: 1f3b0f8243 ("tick/nohz: Optimize nohz idle enter")
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Sanjeev Yadav<sanjeev.yadav@spreadtrum.com>
Cc: Gaurav Jindal<gaurav.jindal@spreadtrum.com>
Cc: stable@vger.kernel.org
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/r/1472798303-4154-1-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-02 10:25:40 +02:00
Vegard Nossum
979515c564 time: Avoid undefined behaviour in ktime_add_safe()
I ran into this:

    ================================================================================
    UBSAN: Undefined behaviour in kernel/time/hrtimer.c:310:16
    signed integer overflow:
    9223372036854775807 + 50000 cannot be represented in type 'long long int'
    CPU: 2 PID: 4798 Comm: trinity-c2 Not tainted 4.8.0-rc1+ #91
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
     0000000000000000 ffff88010ce6fb88 ffffffff82344740 0000000041b58ab3
     ffffffff84f97a20 ffffffff82344694 ffff88010ce6fbb0 ffff88010ce6fb60
     000000000000c350 ffff88010ce6f968 dffffc0000000000 ffffffff857bc320
    Call Trace:
     [<ffffffff82344740>] dump_stack+0xac/0xfc
     [<ffffffff82344694>] ? _atomic_dec_and_lock+0xc4/0xc4
     [<ffffffff8242df78>] ubsan_epilogue+0xd/0x8a
     [<ffffffff8242e6b4>] handle_overflow+0x202/0x23d
     [<ffffffff8242e4b2>] ? val_to_string.constprop.6+0x11e/0x11e
     [<ffffffff8236df71>] ? timerqueue_add+0x151/0x410
     [<ffffffff81485c48>] ? hrtimer_start_range_ns+0x3b8/0x1380
     [<ffffffff81795631>] ? memset+0x31/0x40
     [<ffffffff8242e6fd>] __ubsan_handle_add_overflow+0xe/0x10
     [<ffffffff81488ac9>] hrtimer_nanosleep+0x5d9/0x790
     [<ffffffff814884f0>] ? hrtimer_init_sleeper+0x80/0x80
     [<ffffffff813a9ffb>] ? __might_sleep+0x5b/0x260
     [<ffffffff8148be10>] common_nsleep+0x20/0x30
     [<ffffffff814906c7>] SyS_clock_nanosleep+0x197/0x210
     [<ffffffff81490530>] ? SyS_clock_getres+0x150/0x150
     [<ffffffff823c7113>] ? __this_cpu_preempt_check+0x13/0x20
     [<ffffffff8162ef60>] ? __context_tracking_exit.part.3+0x30/0x1b0
     [<ffffffff81490530>] ? SyS_clock_getres+0x150/0x150
     [<ffffffff81007bd3>] do_syscall_64+0x1b3/0x4b0
     [<ffffffff845f85aa>] entry_SYSCALL64_slow_path+0x25/0x25
    ================================================================================

Add a new ktime_add_unsafe() helper which doesn't check for overflow, but
doesn't throw a UBSAN warning when it does overflow either.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-08-31 14:43:36 -07:00
Vegard Nossum
469e857f37 time: Avoid undefined behaviour in timespec64_add_safe()
I ran into this:

    ================================================================================
    UBSAN: Undefined behaviour in kernel/time/time.c:783:2
    signed integer overflow:
    5273 + 9223372036854771711 cannot be represented in type 'long int'
    CPU: 0 PID: 17363 Comm: trinity-c0 Not tainted 4.8.0-rc1+ #88
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org
    04/01/2014
     0000000000000000 ffff88011457f8f0 ffffffff82344f50 0000000041b58ab3
     ffffffff84f98080 ffffffff82344ea4 ffff88011457f918 ffff88011457f8c8
     ffff88011457f8e0 7fffffffffffefff ffff88011457f6d8 dffffc0000000000
    Call Trace:
     [<ffffffff82344f50>] dump_stack+0xac/0xfc
     [<ffffffff82344ea4>] ? _atomic_dec_and_lock+0xc4/0xc4
     [<ffffffff8242f4c8>] ubsan_epilogue+0xd/0x8a
     [<ffffffff8242fc04>] handle_overflow+0x202/0x23d
     [<ffffffff8242fa02>] ? val_to_string.constprop.6+0x11e/0x11e
     [<ffffffff823c7837>] ? debug_smp_processor_id+0x17/0x20
     [<ffffffff8131b581>] ? __sigqueue_free.part.13+0x51/0x70
     [<ffffffff8146d4e0>] ? rcu_is_watching+0x110/0x110
     [<ffffffff8242fc4d>] __ubsan_handle_add_overflow+0xe/0x10
     [<ffffffff81476ef8>] timespec64_add_safe+0x298/0x340
     [<ffffffff81476c60>] ? timespec_add_safe+0x330/0x330
     [<ffffffff812f7990>] ? wait_noreap_copyout+0x1d0/0x1d0
     [<ffffffff8184bf18>] poll_select_set_timeout+0xf8/0x170
     [<ffffffff8184be20>] ? poll_schedule_timeout+0x2b0/0x2b0
     [<ffffffff813aa9bb>] ? __might_sleep+0x5b/0x260
     [<ffffffff833c8a87>] __sys_recvmmsg+0x107/0x790
     [<ffffffff833c8980>] ? SyS_recvmsg+0x20/0x20
     [<ffffffff81486378>] ? hrtimer_start_range_ns+0x3b8/0x1380
     [<ffffffff845f8bfb>] ? _raw_spin_unlock_irqrestore+0x3b/0x60
     [<ffffffff8148bcea>] ? do_setitimer+0x39a/0x8e0
     [<ffffffff813aa9bb>] ? __might_sleep+0x5b/0x260
     [<ffffffff833c9110>] ? __sys_recvmmsg+0x790/0x790
     [<ffffffff833c91e9>] SyS_recvmmsg+0xd9/0x160
     [<ffffffff833c9110>] ? __sys_recvmmsg+0x790/0x790
     [<ffffffff823c7853>] ? __this_cpu_preempt_check+0x13/0x20
     [<ffffffff8162f680>] ? __context_tracking_exit.part.3+0x30/0x1b0
     [<ffffffff833c9110>] ? __sys_recvmmsg+0x790/0x790
     [<ffffffff81007bd3>] do_syscall_64+0x1b3/0x4b0
     [<ffffffff845f936a>] entry_SYSCALL64_slow_path+0x25/0x25
    ================================================================================

Line 783 is this:

783         set_normalized_timespec64(&res, lhs.tv_sec + rhs.tv_sec,
784                         lhs.tv_nsec + rhs.tv_nsec);

In other words, since lhs.tv_sec and rhs.tv_sec are both time64_t, this
is a signed addition which will cause undefined behaviour on overflow.

Note that this is not currently a huge concern since the kernel should be
built with -fno-strict-overflow by default, but could be a problem in the
future, a problem with older compilers, or other compilers than gcc.

The easiest way to avoid the overflow is to cast one of the arguments to
unsigned (so the addition will be done using unsigned arithmetic).

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-08-31 14:43:35 -07:00
Ruchi Kandoi
0bf43f15db timekeeping: Prints the amounts of time spent during suspend
In addition to keeping a histogram of suspend times, also
print out the time spent in suspend to dmesg.

This helps to keep track of suspend time while debugging using
kernel logs.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
[jstultz: Tweaked commit message]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-08-31 14:43:34 -07:00
Kyle Walker
36374583f9 clocksource: Defer override invalidation unless clock is unstable
Clocksources don't get the VALID_FOR_HRES flag until they have been
checked by a watchdog. However, when using an override, the
clocksource_select logic will clear the override value if the
clocksource is not marked VALID_FOR_HRES during that inititial check.
When using the boot arguments clocksource=<foo>, this selection can
run before the watchdog, and can cause the override to be incorrectly
cleared.

To address this condition, the override_name is only invalidated for
unstable clocksources. Otherwise, the override is left intact until after
the watchdog has validated the clocksource as stable/unstable.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Kyle Walker <kwalker@redhat.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-08-31 14:43:33 -07:00
Pratyush Patel
b4d90e9f1e hrtimer: Spelling fixes
Fix a minor spelling error.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Pratyush Patel <pratyushpatel.1995@gmail.com>
[jstultz: Added commit message]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-08-31 14:43:20 -07:00
John Stultz
a4f8f6667f timekeeping: Cap array access in timekeeping_debug
It was reported that hibernation could fail on the 2nd attempt, where the
system hangs at hibernate() -> syscore_resume() -> i8237A_resume() ->
claim_dma_lock(), because the lock has already been taken.

However there is actually no other process would like to grab this lock on
that problematic platform.

Further investigation showed that the problem is triggered by setting
/sys/power/pm_trace to 1 before the 1st hibernation.

Since once pm_trace is enabled, the rtc becomes unmeaningful after suspend,
and meanwhile some BIOSes would like to adjust the 'invalid' RTC (e.g, smaller
than 1970) to the release date of that motherboard during POST stage, thus
after resumed, it may seem that the system had a significant long sleep time
which is a completely meaningless value.

Then in timekeeping_resume -> tk_debug_account_sleep_time, if the bit31 of the
sleep time happened to be set to 1, fls() returns 32 and we add 1 to
sleep_time_bin[32], which causes an out of bounds array access and therefor
memory being overwritten.

As depicted by System.map:
0xffffffff81c9d080 b sleep_time_bin
0xffffffff81c9d100 B dma_spin_lock
the dma_spin_lock.val is set to 1, which caused this problem.

This patch adds a sanity check in tk_debug_account_sleep_time()
to ensure we don't index past the sleep_time_bin array.

[jstultz: Problem diagnosed and original patch by Chen Yu, I've solved the
 issue slightly differently, but borrowed his excelent explanation of the
 issue here.]

Fixes: 5c83545f24 "power: Add option to log time spent in suspend"
Reported-by: Janek Kozicki <cosurgi@gmail.com>
Reported-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: linux-pm@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xunlei Pang <xpang@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: stable <stable@vger.kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Link: http://lkml.kernel.org/r/1471993702-29148-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-08-24 09:34:32 +02:00
John Stultz
27727df240 timekeeping: Avoid taking lock in NMI path with CONFIG_DEBUG_TIMEKEEPING
When I added some extra sanity checking in timekeeping_get_ns() under
CONFIG_DEBUG_TIMEKEEPING, I missed that the NMI safe __ktime_get_fast_ns()
method was using timekeeping_get_ns().

Thus the locking added to the debug checks broke the NMI-safety of
__ktime_get_fast_ns().

This patch open-codes the timekeeping_get_ns() logic for
__ktime_get_fast_ns(), so can avoid any deadlocks in NMI.

Fixes: 4ca22c2648 "timekeeping: Add warnings when overflows or underflows are observed"
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: stable <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1471993702-29148-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-08-24 09:34:31 +02:00
Chris Metcalf
46c8f0b077 timers: Fix get_next_timer_interrupt() computation
The tick_nohz_stop_sched_tick() routine is not properly
canceling the sched timer when nothing is pending, because
get_next_timer_interrupt() is no longer returning KTIME_MAX in
that case.  This causes periodic interrupts when none are needed.

When determining the next interrupt time, we first use
__next_timer_interrupt() to get the first expiring timer in the
timer wheel.  If no timer is found, we return the base clock value
plus NEXT_TIMER_MAX_DELTA to indicate there is no timer in the
timer wheel.

Back in get_next_timer_interrupt(), we set the "expires" value
by converting the timer wheel expiry (in ticks) to a nsec value.
But we don't want to do this if the timer wheel expiry value
indicates no timer; we want to return KTIME_MAX.

Prior to commit 500462a9de ("timers: Switch to a non-cascading
wheel") we checked base->active_timers to see if any timers
were active, and if not, we didn't touch the expiry value and so
properly returned KTIME_MAX.  Now we don't have active_timers.

To fix this, we now just check the timer wheel expiry value to
see if it is "now + NEXT_TIMER_MAX_DELTA", and if it is, we don't
try to compute a new value based on it, but instead simply let the
KTIME_MAX value in expires remain.

Fixes: 500462a9de "timers: Switch to a non-cascading wheel"
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/1470688147-22287-1-git-send-email-cmetcalf@mellanox.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-08-09 09:31:55 +02:00
Linus Torvalds
a6408f6cb6 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp hotplug updates from Thomas Gleixner:
 "This is the next part of the hotplug rework.

   - Convert all notifiers with a priority assigned

   - Convert all CPU_STARTING/DYING notifiers

     The final removal of the STARTING/DYING infrastructure will happen
     when the merge window closes.

  Another 700 hundred line of unpenetrable maze gone :)"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  timers/core: Correct callback order during CPU hot plug
  leds/trigger/cpu: Move from CPU_STARTING to ONLINE level
  powerpc/numa: Convert to hotplug state machine
  arm/perf: Fix hotplug state machine conversion
  irqchip/armada: Avoid unused function warnings
  ARC/time: Convert to hotplug state machine
  clocksource/atlas7: Convert to hotplug state machine
  clocksource/armada-370-xp: Convert to hotplug state machine
  clocksource/exynos_mct: Convert to hotplug state machine
  clocksource/arm_global_timer: Convert to hotplug state machine
  rcu: Convert rcutree to hotplug state machine
  KVM/arm/arm64/vgic-new: Convert to hotplug state machine
  smp/cfd: Convert core to hotplug state machine
  x86/x2apic: Convert to CPU hotplug state machine
  profile: Convert to hotplug state machine
  timers/core: Convert to hotplug state machine
  hrtimer: Convert to hotplug state machine
  x86/tboot: Convert to hotplug state machine
  arm64/armv8 deprecated: Convert to hotplug state machine
  hwtracing/coresight-etm4x: Convert to hotplug state machine
  ...
2016-07-29 13:55:30 -07:00
Linus Torvalds
55392c4c06 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
 "This update provides the following changes:

   - The rework of the timer wheel which addresses the shortcomings of
     the current wheel (cascading, slow search for next expiring timer,
     etc).  That's the first major change of the wheel in almost 20
     years since Finn implemted it.

   - A large overhaul of the clocksource drivers init functions to
     consolidate the Device Tree initialization

   - Some more Y2038 updates

   - A capability fix for timerfd

   - Yet another clock chip driver

   - The usual pile of updates, comment improvements all over the place"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (130 commits)
  tick/nohz: Optimize nohz idle enter
  clockevents: Make clockevents_subsys static
  clocksource/drivers/time-armada-370-xp: Fix return value check
  timers: Implement optimization for same expiry time in mod_timer()
  timers: Split out index calculation
  timers: Only wake softirq if necessary
  timers: Forward the wheel clock whenever possible
  timers/nohz: Remove pointless tick_nohz_kick_tick() function
  timers: Optimize collect_expired_timers() for NOHZ
  timers: Move __run_timers() function
  timers: Remove set_timer_slack() leftovers
  timers: Switch to a non-cascading wheel
  timers: Reduce the CPU index space to 256k
  timers: Give a few structs and members proper names
  hlist: Add hlist_is_singular_node() helper
  signals: Use hrtimer for sigtimedwait()
  timers: Remove the deprecated mod_timer_pinned() API
  timers, net/ipv4/inet: Initialize connection request timers as pinned
  timers, drivers/tty/mips_ejtag: Initialize the poll timer as pinned
  timers, drivers/tty/metag_da: Initialize the poll timer as pinned
  ...
2016-07-25 20:43:12 -07:00
Linus Torvalds
25a0dc4be8 Merge tag 'staging-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging and IIO driver updates from Greg KH:
 "Here is the big Staging and IIO driver update for 4.8-rc1.

  We ended up adding more code than removing, again, but it's not all
  that bad.  Lots of cleanups all over the staging tree, and new IIO
  drivers, full details in the shortlog.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (417 commits)
  drivers:iio:accel:mma8452: removed unwanted return statements
  drivers:iio:accel:mma8452: added cleanup provision in case of failure.
  iio: Add iio.git tree to MAINTAINERS
  iio:st_pressure: clean useless static channel initializers
  iio:st_pressure:lps22hb: temperature support
  iio:st_pressure:lps22hb: open drain support
  iio:st_pressure: temperature triggered buffering
  iio:st_pressure: document sampling gains
  iio:st_pressure: align storagebits on power of 2
  iio:st_sensors: align on storagebits boundaries
  staging:iio:lis3l02dq drop separate driver
  iio: accel: st_accel: Add lis3l02dq support
  iio: adc: add missing of_node references to iio_dev
  iio: adc: ti-ads1015: add indio_dev->dev.of_node reference
  iio: potentiometer: Fix typo in Kconfig
  iio: potentiometer: mcp4531: Add device tree binding
  iio: potentiometer: mcp4531: Add device tree binding documentation
  iio: potentiometer: mcp4531: Add support for MCP454x, MCP456x, MCP464x and MCP466x
  iio:imu:mpu6050: icm20608 initial support
  iio: adc: max1363: Add device tree binding
  ...
2016-07-24 16:55:23 -07:00
Gaurav Jindal
1f3b0f8243 tick/nohz: Optimize nohz idle enter
tick_nohz_start_idle is called before checking whether the idle tick can be
stopped. If the tick cannot be stopped, calling tick_nohz_start_idle() is
pointless and just wasting CPU cycles.

Only invoke tick_nohz_start_idle() when can_stop_idle_tick() returns true. A
short one minute observation of the effect on ARM64 shows a reduction of calls
by 1.5% thus optimizing the idle entry sequence.

[tglx: Massaged changelog ]

Co-developed-by: Sanjeev Yadav<sanjeev.yadav@spreadtrum.com>
Signed-off-by: Gaurav Jindal<gaurav.jindal@spreadtrum.com>
Link: http://lkml.kernel.org/r/20160714120416.GB21099@gaurav.jindal@spreadtrum.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-07-19 13:48:24 +02:00
Ben Dooks
775be50626 clockevents: Make clockevents_subsys static
The clockevents_subsys struct is used for sysfs support and
is not declared or used outside the file it is defined in.
Fix the following warning by making it static:

kernel/time/clockevents.c:648:17: warning: symbol 'clockevents_subsys' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Cc: linux-kernel@lists.codethink.co.uk
Link: http://lkml.kernel.org/r/1466178974-7105-1-git-send-email-ben.dooks@codethink.co.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-07-19 10:48:06 +02:00
Richard Cochran
24f73b9971 timers/core: Convert to hotplug state machine
When tearing down, call timers_dead_cpu() before notify_dead().
There is a hidden dependency between:

 - timers
 - block multiqueue
 - rcutree

If timers_dead_cpu() comes later than blk_mq_queue_reinit_notify()
that latter function causes a RCU stall.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153337.566790058@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-15 10:41:42 +02:00
Thomas Gleixner
27590dc17b hrtimer: Convert to hotplug state machine
Split out the clockevents callbacks instead of piggybacking them on
hrtimers.

This gets rid of a POST_DEAD user. See commit:

  54e88fad22 ("sched: Make sure timers have migrated before killing the migration_thread")

We just move the callback state to the proper place in the state machine.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153337.485419196@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-15 10:41:37 +02:00