30 Dec, 2020

2 commits

  • Changes in 5.10.4
    hwmon: (k10temp) Remove support for displaying voltage and current on Zen CPUs
    drm/gma500: fix double free of gma_connector
    iio: adc: at91_adc: add Kconfig dep on the OF symbol and remove of_match_ptr()
    drm/aspeed: Fix Kconfig warning & subsequent build errors
    drm/mcde: Fix handling of platform_get_irq() error
    drm/tve200: Fix handling of platform_get_irq() error
    arm64: dts: renesas: hihope-rzg2-ex: Drop rxc-skew-ps from ethernet-phy node
    arm64: dts: renesas: cat875: Remove rxc-skew-ps from ethernet-phy node
    soc: renesas: rmobile-sysc: Fix some leaks in rmobile_init_pm_domains()
    soc: mediatek: Check if power domains can be powered on at boot time
    arm64: dts: mediatek: mt8183: fix gce incorrect mbox-cells value
    arm64: dts: ipq6018: update the reserved-memory node
    arm64: dts: qcom: sc7180: Fix one forgotten interconnect reference
    soc: qcom: geni: More properly switch to DMA mode
    Revert "i2c: i2c-qcom-geni: Fix DMA transfer race"
    RDMA/bnxt_re: Set queue pair state when being queried
    rtc: pcf2127: fix pcf2127_nvmem_read/write() returns
    RDMA/bnxt_re: Fix entry size during SRQ create
    selinux: fix error initialization in inode_doinit_with_dentry()
    ARM: dts: aspeed-g6: Fix the GPIO memory size
    ARM: dts: aspeed: s2600wf: Fix VGA memory region location
    RDMA/core: Fix error return in _ib_modify_qp()
    RDMA/rxe: Compute PSN windows correctly
    x86/mm/ident_map: Check for errors from ident_pud_init()
    ARM: p2v: fix handling of LPAE translation in BE mode
    RDMA/rtrs-clt: Remove destroy_con_cq_qp in case route resolving failed
    RDMA/rtrs-clt: Missing error from rtrs_rdma_conn_established
    RDMA/rtrs-srv: Don't guard the whole __alloc_srv with srv_mutex
    x86/apic: Fix x2apic enablement without interrupt remapping
    ASoC: qcom: fix unsigned int bitwidth compared to less than zero
    sched/deadline: Fix sched_dl_global_validate()
    sched: Reenable interrupts in do_sched_yield()
    drm/amdgpu: fix incorrect enum type
    crypto: talitos - Endianess in current_desc_hdr()
    crypto: talitos - Fix return type of current_desc_hdr()
    crypto: inside-secure - Fix sizeof() mismatch
    ASoC: sun4i-i2s: Fix lrck_period computation for I2S justified mode
    drm/msm: Add missing stub definition
    ARM: dts: aspeed: tiogapass: Remove vuart
    drm/amdgpu: fix build_coefficients() argument
    powerpc/64: Set up a kernel stack for secondaries before cpu_restore()
    spi: img-spfi: fix reference leak in img_spfi_resume
    f2fs: call f2fs_get_meta_page_retry for nat page
    RDMA/mlx5: Fix corruption of reg_pages in mlx5_ib_rereg_user_mr()
    perf test: Use generic event for expand_libpfm_events()
    drm/msm/dp: DisplayPort PHY compliance tests fixup
    drm/msm/dsi_pll_7nm: restore VCO rate during restore_state
    drm/msm/dsi_pll_10nm: restore VCO rate during restore_state
    drm/msm/dpu: fix clock scaling on non-sc7180 board
    spi: spi-mem: fix reference leak in spi_mem_access_start
    scsi: aacraid: Improve compat_ioctl handlers
    pinctrl: core: Add missing #ifdef CONFIG_GPIOLIB
    ASoC: pcm: DRAIN support reactivation
    drm/bridge: tpd12s015: Fix irq registering in tpd12s015_probe
    crypto: arm64/poly1305-neon - reorder PAC authentication with SP update
    crypto: arm/aes-neonbs - fix usage of cbc(aes) fallback
    crypto: caam - fix printing on xts fallback allocation error path
    selinux: fix inode_doinit_with_dentry() LABEL_INVALID error handling
    nl80211/cfg80211: fix potential infinite loop
    spi: stm32: fix reference leak in stm32_spi_resume
    bpf: Fix tests for local_storage
    x86/mce: Correct the detection of invalid notifier priorities
    drm/edid: Fix uninitialized variable in drm_cvt_modes()
    ath11k: Initialize complete alpha2 for regulatory change
    ath11k: Fix number of rules in filtered ETSI regdomain
    ath11k: fix wmi init configuration
    brcmfmac: Fix memory leak for unpaired brcmf_{alloc/free}
    arm64: dts: exynos: Include common syscon restart/poweroff for Exynos7
    arm64: dts: exynos: Correct psci compatible used on Exynos7
    drm/panel: simple: Add flags to boe_nv133fhm_n61
    Bluetooth: Fix null pointer dereference in hci_event_packet()
    Bluetooth: Fix: LL PRivacy BLE device fails to connect
    Bluetooth: hci_h5: fix memory leak in h5_close
    spi: stm32-qspi: fix reference leak in stm32 qspi operations
    spi: spi-ti-qspi: fix reference leak in ti_qspi_setup
    spi: mt7621: fix missing clk_disable_unprepare() on error in mt7621_spi_probe
    spi: tegra20-slink: fix reference leak in slink ops of tegra20
    spi: tegra20-sflash: fix reference leak in tegra_sflash_resume
    spi: tegra114: fix reference leak in tegra spi ops
    spi: bcm63xx-hsspi: fix missing clk_disable_unprepare() on error in bcm63xx_hsspi_resume
    spi: imx: fix reference leak in two imx operations
    ASoC: qcom: common: Fix refcounting in qcom_snd_parse_of()
    ath11k: Handle errors if peer creation fails
    mwifiex: fix mwifiex_shutdown_sw() causing sw reset failure
    drm/msm/a6xx: Clear shadow on suspend
    drm/msm/a5xx: Clear shadow on suspend
    firmware: tegra: fix strncpy()/strncat() confusion
    drm/msm/dp: return correct connection status after suspend
    drm/msm/dp: skip checking LINK_STATUS_UPDATED bit
    drm/msm/dp: do not notify audio subsystem if sink doesn't support audio
    selftests/run_kselftest.sh: fix dry-run typo
    selftest/bpf: Add missed ip6ip6 test back
    ASoC: wm8994: Fix PM disable depth imbalance on error
    ASoC: wm8998: Fix PM disable depth imbalance on error
    spi: sprd: fix reference leak in sprd_spi_remove
    virtiofs fix leak in setup
    ASoC: arizona: Fix a wrong free in wm8997_probe
    RDMa/mthca: Work around -Wenum-conversion warning
    ASoC: SOF: Intel: fix Kconfig dependency for SND_INTEL_DSP_CONFIG
    arm64: dts: ti: k3-am65*/j721e*: Fix unit address format error for dss node
    MIPS: BCM47XX: fix kconfig dependency bug for BCM47XX_BCMA
    drm/amdgpu: fix compute queue priority if num_kcq is less than 4
    soc: ti: omap-prm: Do not check rstst bit on deassert if already deasserted
    crypto: Kconfig - CRYPTO_MANAGER_EXTRA_TESTS requires the manager
    crypto: qat - fix status check in qat_hal_put_rel_rd_xfer()
    firmware: arm_scmi: Fix missing destroy_workqueue()
    drm/udl: Fix missing error code in udl_handle_damage()
    staging: greybus: codecs: Fix reference counter leak in error handling
    staging: gasket: interrupt: fix the missed eventfd_ctx_put() in gasket_interrupt.c
    scripts: kernel-doc: Restore anonymous enum parsing
    drm/amdkfd: Put ACPI table after using it
    ionic: use mc sync for multicast filters
    ionic: flatten calls to ionic_lif_rx_mode
    ionic: change set_rx_mode from_ndo to can_sleep
    media: tm6000: Fix sizeof() mismatches
    media: platform: add missing put_device() call in mtk_jpeg_clk_init()
    media: mtk-vcodec: add missing put_device() call in mtk_vcodec_init_dec_pm()
    media: mtk-vcodec: add missing put_device() call in mtk_vcodec_release_dec_pm()
    media: mtk-vcodec: add missing put_device() call in mtk_vcodec_init_enc_pm()
    media: v4l2-fwnode: Return -EINVAL for invalid bus-type
    media: v4l2-fwnode: v4l2_fwnode_endpoint_parse caller must init vep argument
    media: ov5640: fix support of BT656 bus mode
    media: staging: rkisp1: cap: fix runtime PM imbalance on error
    media: cedrus: fix reference leak in cedrus_start_streaming
    media: platform: add missing put_device() call in mtk_jpeg_probe() and mtk_jpeg_remove()
    media: venus: core: change clk enable and disable order in resume and suspend
    media: venus: core: vote for video-mem path
    media: venus: core: vote with average bandwidth and peak bandwidth as zero
    RDMA/cma: Add missing error handling of listen_id
    ASoC: meson: fix COMPILE_TEST error
    spi: dw: fix build error by selecting MULTIPLEXER
    scsi: core: Fix VPD LUN ID designator priorities
    media: venus: put dummy vote on video-mem path after last session release
    media: solo6x10: fix missing snd_card_free in error handling case
    video: fbdev: atmel_lcdfb: fix return error code in atmel_lcdfb_of_init()
    mmc: sdhci: tegra: fix wrong unit with busy_timeout
    drm/omap: dmm_tiler: fix return error code in omap_dmm_probe()
    drm/meson: Free RDMA resources after tearing down DRM
    drm/meson: Unbind all connectors on module removal
    drm/meson: dw-hdmi: Register a callback to disable the regulator
    drm/meson: dw-hdmi: Ensure that clocks are enabled before touching the TOP registers
    ASoC: intel: SND_SOC_INTEL_KEEMBAY should depend on ARCH_KEEMBAY
    iommu/vt-d: include conditionally on CONFIG_INTEL_IOMMU_SVM
    Input: ads7846 - fix race that causes missing releases
    Input: ads7846 - fix integer overflow on Rt calculation
    Input: ads7846 - fix unaligned access on 7845
    bus: mhi: core: Remove double locking from mhi_driver_remove()
    bus: mhi: core: Fix null pointer access when parsing MHI configuration
    usb/max3421: fix return error code in max3421_probe()
    spi: mxs: fix reference leak in mxs_spi_probe
    selftests/bpf: Fix broken riscv build
    powerpc: Avoid broken GCC __attribute__((optimize))
    powerpc/feature: Fix CPU_FTRS_ALWAYS by removing CPU_FTRS_GENERIC_32
    ARM: dts: tacoma: Fix node vs reg mismatch for flash memory
    Revert "powerpc/pseries/hotplug-cpu: Remove double free in error path"
    powerpc/powernv/sriov: fix unsigned int win compared to less than zero
    mfd: htc-i2cpld: Add the missed i2c_put_adapter() in htcpld_register_chip_i2c()
    mfd: MFD_SL28CPLD should depend on ARCH_LAYERSCAPE
    mfd: stmfx: Fix dev_err_probe() call in stmfx_chip_init()
    mfd: cpcap: Fix interrupt regression with regmap clear_ack
    EDAC/mce_amd: Use struct cpuinfo_x86.cpu_die_id for AMD NodeId
    scsi: ufs: Avoid to call REQ_CLKS_OFF to CLKS_OFF
    scsi: ufs: Fix clkgating on/off
    rcu: Allow rcu_irq_enter_check_tick() from NMI
    rcu,ftrace: Fix ftrace recursion
    rcu/tree: Defer kvfree_rcu() allocation to a clean context
    crypto: crypto4xx - Replace bitwise OR with logical OR in crypto4xx_build_pd
    crypto: omap-aes - Fix PM disable depth imbalance in omap_aes_probe
    crypto: sun8i-ce - fix two error path's memory leak
    spi: fix resource leak for drivers without .remove callback
    drm/meson: dw-hdmi: Disable clocks on driver teardown
    drm/meson: dw-hdmi: Enable the iahb clock early enough
    PCI: Disable MSI for Pericom PCIe-USB adapter
    PCI: brcmstb: Initialize "tmp" before use
    soc: ti: knav_qmss: fix reference leak in knav_queue_probe
    soc: ti: Fix reference imbalance in knav_dma_probe
    drivers: soc: ti: knav_qmss_queue: Fix error return code in knav_queue_probe
    soc: qcom: initialize local variable
    arm64: dts: qcom: sm8250: correct compatible for sm8250-mtp
    arm64: dts: qcom: msm8916-samsung-a2015: Disable muic i2c pin bias
    Input: omap4-keypad - fix runtime PM error handling
    clk: meson: Kconfig: fix dependency for G12A
    staging: mfd: hi6421-spmi-pmic: fix error return code in hi6421_spmi_pmic_probe()
    ath11k: Fix the rx_filter flag setting for peer rssi stats
    RDMA/cxgb4: Validate the number of CQEs
    soundwire: Fix DEBUG_LOCKS_WARN_ON for uninitialized attribute
    pinctrl: sunxi: fix irq bank map for the Allwinner A100 pin controller
    memstick: fix a double-free bug in memstick_check
    ARM: dts: at91: sam9x60: add pincontrol for USB Host
    ARM: dts: at91: sama5d4_xplained: add pincontrol for USB Host
    ARM: dts: at91: sama5d3_xplained: add pincontrol for USB Host
    mmc: pxamci: Fix error return code in pxamci_probe
    brcmfmac: fix error return code in brcmf_cfg80211_connect()
    orinoco: Move context allocation after processing the skb
    qtnfmac: fix error return code in qtnf_pcie_probe()
    rsi: fix error return code in rsi_reset_card()
    cw1200: fix missing destroy_workqueue() on error in cw1200_init_common
    dmaengine: mv_xor_v2: Fix error return code in mv_xor_v2_probe()
    arm64: dts: qcom: sdm845: Limit ipa iommu streams
    leds: netxbig: add missing put_device() call in netxbig_leds_get_of_pdata()
    leds: lp50xx: Fix an error handling path in 'lp50xx_probe_dt()'
    leds: turris-omnia: check for LED_COLOR_ID_RGB instead LED_COLOR_ID_MULTI
    arm64: tegra: Fix DT binding for IO High Voltage entry
    RDMA/cma: Fix deadlock on &lock in rdma_cma_listen_on_all() error unwind
    soundwire: qcom: Fix build failure when slimbus is module
    drm/imx/dcss: fix rotations for Vivante tiled formats
    media: siano: fix memory leak of debugfs members in smsdvb_hotplug
    platform/x86: mlx-platform: Remove PSU EEPROM from default platform configuration
    platform/x86: mlx-platform: Remove PSU EEPROM from MSN274x platform configuration
    arm64: dts: qcom: sc7180: limit IPA iommu streams
    RDMA/hns: Only record vlan info for HIP08
    RDMA/hns: Fix missing fields in address vector
    RDMA/hns: Avoid setting loopback indicator when smac is same as dmac
    serial: 8250-mtk: Fix reference leak in mtk8250_probe
    samples: bpf: Fix lwt_len_hist reusing previous BPF map
    media: imx214: Fix stop streaming
    mips: cdmm: fix use-after-free in mips_cdmm_bus_discover
    media: max2175: fix max2175_set_csm_mode() error code
    slimbus: qcom-ngd-ctrl: Avoid sending power requests without QMI
    RDMA/core: Track device memory MRs
    drm/mediatek: Use correct aliases name for ovl
    HSI: omap_ssi: Don't jump to free ID in ssi_add_controller()
    ARM: dts: Remove non-existent i2c1 from 98dx3236
    arm64: dts: armada-3720-turris-mox: update ethernet-phy handle name
    power: supply: bq25890: Use the correct range for IILIM register
    arm64: dts: rockchip: Set dr_mode to "host" for OTG on rk3328-roc-cc
    power: supply: max17042_battery: Fix current_{avg,now} hiding with no current sense
    power: supply: axp288_charger: Fix HP Pavilion x2 10 DMI matching
    power: supply: bq24190_charger: fix reference leak
    genirq/irqdomain: Don't try to free an interrupt that has no mapping
    arm64: dts: ls1028a: fix ENETC PTP clock input
    arm64: dts: ls1028a: fix FlexSPI clock input
    arm64: dts: freescale: sl28: combine SPI MTD partitions
    phy: tegra: xusb: Fix usb_phy device driver field
    arm64: dts: qcom: c630: Polish i2c-hid devices
    arm64: dts: qcom: c630: Fix pinctrl pins properties
    PCI: Bounds-check command-line resource alignment requests
    PCI: Fix overflow in command-line resource alignment requests
    PCI: iproc: Fix out-of-bound array accesses
    PCI: iproc: Invalidate correct PAXB inbound windows
    arm64: dts: meson: fix spi-max-frequency on Khadas VIM2
    arm64: dts: meson-sm1: fix typo in opp table
    soc: amlogic: canvas: add missing put_device() call in meson_canvas_get()
    scsi: hisi_sas: Fix up probe error handling for v3 hw
    scsi: pm80xx: Do not sleep in atomic context
    spi: spi-fsl-dspi: Use max_native_cs instead of num_chipselect to set SPI_MCR
    ARM: dts: at91: at91sam9rl: fix ADC triggers
    RDMA/hns: Fix 0-length sge calculation error
    RDMA/hns: Bugfix for calculation of extended sge
    mailbox: arm_mhu_db: Fix mhu_db_shutdown by replacing kfree with devm_kfree
    soundwire: master: use pm_runtime_set_active() on add
    platform/x86: dell-smbios-base: Fix error return code in dell_smbios_init
    ASoC: Intel: Boards: tgl_max98373: update TDM slot_width
    media: max9271: Fix GPIO enable/disable
    media: rdacm20: Enable GPIO1 explicitly
    media: i2c: imx219: Selection compliance fixes
    ath11k: Don't cast ath11k_skb_cb to ieee80211_tx_info.control
    ath11k: Reset ath11k_skb_cb before setting new flags
    ath11k: Fix an error handling path
    ath10k: Fix the parsing error in service available event
    ath10k: Fix an error handling path
    ath10k: Release some resources in an error handling path
    SUNRPC: rpc_wake_up() should wake up tasks in the correct order
    NFSv4.2: condition READDIR's mask for security label based on LSM state
    SUNRPC: xprt_load_transport() needs to support the netid "rdma6"
    NFSv4: Fix the alignment of page data in the getdeviceinfo reply
    net: sunrpc: Fix 'snprintf' return value check in 'do_xprt_debugfs'
    lockd: don't use interval-based rebinding over TCP
    NFS: switch nfsiod to be an UNBOUND workqueue.
    selftests/seccomp: Update kernel config
    vfio-pci: Use io_remap_pfn_range() for PCI IO memory
    hwmon: (ina3221) Fix PM usage counter unbalance in ina3221_write_enable
    f2fs: fix double free of unicode map
    media: tvp5150: Fix wrong return value of tvp5150_parse_dt()
    media: saa7146: fix array overflow in vidioc_s_audio()
    powerpc/perf: Fix crash with is_sier_available when pmu is not set
    powerpc/64: Fix an EMIT_BUG_ENTRY in head_64.S
    powerpc/xmon: Fix build failure for 8xx
    powerpc/perf: Fix to update radix_scope_qual in power10
    powerpc/perf: Update the PMU group constraints for l2l3 events in power10
    powerpc/perf: Fix the PMU group constraints for threshold events in power10
    clocksource/drivers/orion: Add missing clk_disable_unprepare() on error path
    clocksource/drivers/cadence_ttc: Fix memory leak in ttc_setup_clockevent()
    clocksource/drivers/ingenic: Fix section mismatch
    clocksource/drivers/riscv: Make RISCV_TIMER depends on RISCV_SBI
    arm64: mte: fix prctl(PR_GET_TAGGED_ADDR_CTRL) if TCF0=NONE
    iio: hrtimer-trigger: Mark hrtimer to expire in hard interrupt context
    libbpf: Sanitise map names before pinning
    ARM: dts: at91: sam9x60ek: remove bypass property
    ARM: dts: at91: sama5d2: map securam as device
    scripts: kernel-doc: fix parsing function-like typedefs
    bpf: Fix bpf_put_raw_tracepoint()'s use of __module_address()
    selftests/bpf: Fix invalid use of strncat in test_sockmap
    pinctrl: falcon: add missing put_device() call in pinctrl_falcon_probe()
    soc: rockchip: io-domain: Fix error return code in rockchip_iodomain_probe()
    arm64: dts: rockchip: Fix UART pull-ups on rk3328
    memstick: r592: Fix error return in r592_probe()
    MIPS: Don't round up kernel sections size for memblock_add()
    mt76: mt7663s: fix a possible ple quota underflow
    mt76: mt7915: set fops_sta_stats.owner to THIS_MODULE
    mt76: set fops_tx_stats.owner to THIS_MODULE
    mt76: dma: fix possible deadlock running mt76_dma_cleanup
    net/mlx5: Properly convey driver version to firmware
    mt76: fix memory leak if device probing fails
    mt76: fix tkip configuration for mt7615/7663 devices
    ASoC: jz4740-i2s: add missed checks for clk_get()
    ASoC: q6afe-clocks: Add missing parent clock rate
    dm ioctl: fix error return code in target_message
    ASoC: cros_ec_codec: fix uninitialized memory read
    ASoC: atmel: mchp-spdifrx needs COMMON_CLK
    ASoC: qcom: fix QDSP6 dependencies, attempt #3
    phy: mediatek: allow compile-testing the hdmi phy
    phy: renesas: rcar-gen3-usb2: disable runtime pm in case of failure
    memory: ti-emif-sram: only build for ARMv7
    memory: jz4780_nemc: Fix potential NULL dereference in jz4780_nemc_probe()
    drm/msm: a5xx: Make preemption reset case reentrant
    drm/msm: add IOMMU_SUPPORT dependency
    clocksource/drivers/arm_arch_timer: Use stable count reader in erratum sne
    clocksource/drivers/arm_arch_timer: Correct fault programming of CNTKCTL_EL1.EVNTI
    cpufreq: ap806: Add missing MODULE_DEVICE_TABLE
    cpufreq: highbank: Add missing MODULE_DEVICE_TABLE
    cpufreq: mediatek: Add missing MODULE_DEVICE_TABLE
    cpufreq: qcom: Add missing MODULE_DEVICE_TABLE
    cpufreq: st: Add missing MODULE_DEVICE_TABLE
    cpufreq: sun50i: Add missing MODULE_DEVICE_TABLE
    cpufreq: loongson1: Add missing MODULE_ALIAS
    cpufreq: scpi: Add missing MODULE_ALIAS
    cpufreq: vexpress-spc: Add missing MODULE_ALIAS
    cpufreq: imx: fix NVMEM_IMX_OCOTP dependency
    macintosh/adb-iop: Always wait for reply message from IOP
    macintosh/adb-iop: Send correct poll command
    staging: bcm2835: fix vchiq_mmal dependencies
    staging: greybus: audio: Fix possible leak free widgets in gbaudio_dapm_free_controls
    spi: dw: Fix error return code in dw_spi_bt1_probe()
    Bluetooth: btusb: Add the missed release_firmware() in btusb_mtk_setup_firmware()
    Bluetooth: btmtksdio: Add the missed release_firmware() in mtk_setup_firmware()
    Bluetooth: sco: Fix crash when using BT_SNDMTU/BT_RCVMTU option
    block/rnbd-clt: Dynamically alloc buffer for pathname & blk_symlink_name
    block/rnbd: fix a null pointer dereference on dev->blk_symlink_name
    Bluetooth: btusb: Fix detection of some fake CSR controllers with a bcdDevice val of 0x0134
    platform/x86: intel-vbtn: Fix SW_TABLET_MODE always reporting 1 on some HP x360 models
    adm8211: fix error return code in adm8211_probe()
    mtd: spi-nor: sst: fix BPn bits for the SST25VF064C
    mtd: spi-nor: ignore errors in spi_nor_unlock_all()
    mtd: spi-nor: atmel: remove global protection flag
    mtd: spi-nor: atmel: fix unlock_all() for AT25FS010/040
    arm64: dts: meson: g12b: odroid-n2: fix PHY deassert timing requirements
    arm64: dts: meson: fix PHY deassert timing requirements
    ARM: dts: meson: fix PHY deassert timing requirements
    arm64: dts: meson: g12a: x96-max: fix PHY deassert timing requirements
    arm64: dts: meson: g12b: w400: fix PHY deassert timing requirements
    clk: fsl-sai: fix memory leak
    scsi: qedi: Fix missing destroy_workqueue() on error in __qedi_probe
    scsi: pm80xx: Fix error return in pm8001_pci_probe()
    scsi: iscsi: Fix inappropriate use of put_device()
    seq_buf: Avoid type mismatch for seq_buf_init
    scsi: fnic: Fix error return code in fnic_probe()
    platform/x86: mlx-platform: Fix item counter assignment for MSN2700, MSN24xx systems
    platform/x86: mlx-platform: Fix item counter assignment for MSN2700/ComEx system
    ARM: 9030/1: entry: omit FP emulation for UND exceptions taken in kernel mode
    powerpc/pseries/hibernation: drop pseries_suspend_begin() from suspend ops
    powerpc/pseries/hibernation: remove redundant cacheinfo update
    powerpc/powermac: Fix low_sleep_handler with CONFIG_VMAP_STACK
    drm/mediatek: avoid dereferencing a null hdmi_phy on an error message
    ASoC: amd: change clk_get() to devm_clk_get() and add missed checks
    coresight: remove broken __exit annotations
    ASoC: max98390: Fix error codes in max98390_dsm_init()
    powerpc/mm: sanity_check_fault() should work for all, not only BOOK3S
    usb: ehci-omap: Fix PM disable depth umbalance in ehci_hcd_omap_probe
    usb: oxu210hp-hcd: Fix memory leak in oxu_create
    speakup: fix uninitialized flush_lock
    nfsd: Fix message level for normal termination
    NFSD: Fix 5 seconds delay when doing inter server copy
    nfs_common: need lock during iterate through the list
    x86/kprobes: Restore BTF if the single-stepping is cancelled
    scsi: qla2xxx: Fix FW initialization error on big endian machines
    scsi: qla2xxx: Fix N2N and NVMe connect retry failure
    platform/chrome: cros_ec_spi: Don't overwrite spi::mode
    misc: pci_endpoint_test: fix return value of error branch
    bus: fsl-mc: add back accidentally dropped error check
    bus: fsl-mc: fix error return code in fsl_mc_object_allocate()
    fsi: Aspeed: Add mutex to protect HW access
    s390/cio: fix use-after-free in ccw_device_destroy_console
    iwlwifi: dbg-tlv: fix old length in is_trig_data_contained()
    iwlwifi: mvm: hook up missing RX handlers
    erofs: avoid using generic_block_bmap
    clk: renesas: r8a779a0: Fix R and OSC clocks
    can: m_can: m_can_config_endisable(): remove double clearing of clock stop request bit
    powerpc/sstep: Emulate prefixed instructions only when CPU_FTR_ARCH_31 is set
    powerpc/sstep: Cover new VSX instructions under CONFIG_VSX
    slimbus: qcom: fix potential NULL dereference in qcom_slim_prg_slew()
    ALSA: hda/hdmi: fix silent stream for first playback to DP
    RDMA/core: Do not indicate device ready when device enablement fails
    RDMA/uverbs: Fix incorrect variable type
    remoteproc/mediatek: change MT8192 CFG register base
    remoteproc/mtk_scp: surround DT device IDs with CONFIG_OF
    remoteproc: q6v5-mss: fix error handling in q6v5_pds_enable
    remoteproc: qcom: fix reference leak in adsp_start
    remoteproc: qcom: pas: fix error handling in adsp_pds_enable
    remoteproc: k3-dsp: Fix return value check in k3_dsp_rproc_of_get_memories()
    remoteproc: qcom: Fix potential NULL dereference in adsp_init_mmio()
    remoteproc/mediatek: unprepare clk if scp_before_load fails
    clk: qcom: gcc-sc7180: Use floor ops for sdcc clks
    clk: tegra: Fix duplicated SE clock entry
    mtd: rawnand: gpmi: fix reference count leak in gpmi ops
    mtd: rawnand: meson: Fix a resource leak in init
    mtd: rawnand: gpmi: Fix the random DMA timeout issue
    samples/bpf: Fix possible hang in xdpsock with multiple threads
    fs: Handle I_DONTCACHE in iput_final() instead of generic_drop_inode()
    extcon: max77693: Fix modalias string
    crypto: atmel-i2c - select CONFIG_BITREVERSE
    mac80211: don't set set TDLS STA bandwidth wider than possible
    mac80211: fix a mistake check for rx_stats update
    ASoC: wm_adsp: remove "ctl" from list on error in wm_adsp_create_control()
    irqchip/alpine-msi: Fix freeing of interrupts on allocation error path
    irqchip/ti-sci-inta: Fix printing of inta id on probe success
    irqchip/ti-sci-intr: Fix freeing of irqs
    dmaengine: ti: k3-udma: Correct normal channel offset when uchan_cnt is not 0
    RDMA/hns: Limit the length of data copied between kernel and userspace
    RDMA/hns: Normalization the judgment of some features
    RDMA/hns: Do shift on traffic class when using RoCEv2
    gpiolib: irq hooks: fix recursion in gpiochip_irq_unmask
    ath11k: Fix incorrect tlvs in scan start command
    irqchip/qcom-pdc: Fix phantom irq when changing between rising/falling
    watchdog: armada_37xx: Add missing dependency on HAS_IOMEM
    watchdog: sirfsoc: Add missing dependency on HAS_IOMEM
    watchdog: sprd: remove watchdog disable from resume fail path
    watchdog: sprd: check busy bit before new loading rather than after that
    watchdog: Fix potential dereferencing of null pointer
    ubifs: Fix error return code in ubifs_init_authentication()
    um: Monitor error events in IRQ controller
    um: tty: Fix handling of close in tty lines
    um: chan_xterm: Fix fd leak
    sunrpc: fix xs_read_xdr_buf for partial pages receive
    RDMA/mlx5: Fix MR cache memory leak
    RDMA/cma: Don't overwrite sgid_attr after device is released
    nfc: s3fwrn5: Release the nfc firmware
    drm: mxsfb: Silence -EPROBE_DEFER while waiting for bridge
    powerpc/perf: Fix Threshold Event Counter Multiplier width for P10
    powerpc/ps3: use dma_mapping_error()
    perf test: Fix metric parsing test
    drm/amdgpu: fix regression in vbios reservation handling on headless
    mm/gup: reorganize internal_get_user_pages_fast()
    mm/gup: prevent gup_fast from racing with COW during fork
    mm/gup: combine put_compound_head() and unpin_user_page()
    mm: memcg/slab: fix return of child memcg objcg for root memcg
    mm: memcg/slab: fix use after free in obj_cgroup_charge
    mm/rmap: always do TTU_IGNORE_ACCESS
    sparc: fix handling of page table constructor failure
    mm/vmalloc: Fix unlock order in s_stop()
    mm/vmalloc.c: fix kasan shadow poisoning size
    mm,memory_failure: always pin the page in madvise_inject_error
    hugetlb: fix an error code in hugetlb_reserve_pages()
    mm: don't wake kswapd prematurely when watermark boosting is disabled
    proc: fix lookup in /proc/net subdirectories after setns(2)
    checkpatch: fix unescaped left brace
    s390/test_unwind: fix CALL_ON_STACK tests
    lan743x: fix rx_napi_poll/interrupt ping-pong
    ice, xsk: clear the status bits for the next_to_use descriptor
    i40e, xsk: clear the status bits for the next_to_use descriptor
    net: dsa: qca: ar9331: fix sleeping function called from invalid context bug
    dpaa2-eth: fix the size of the mapped SGT buffer
    net: bcmgenet: Fix a resource leak in an error handling path in the probe functin
    net: mscc: ocelot: Fix a resource leak in the error handling path of the probe function
    net: allwinner: Fix some resources leak in the error handling path of the probe and in the remove function
    block/rnbd-clt: Get rid of warning regarding size argument in strlcpy
    block/rnbd-clt: Fix possible memleak
    NFS/pNFS: Fix a typo in ff_layout_resend_pnfs_read()
    net: korina: fix return value
    devlink: use _BITUL() macro instead of BIT() in the UAPI header
    libnvdimm/label: Return -ENXIO for no slot in __blk_label_update
    powerpc/32s: Fix cleanup_cpu_mmu_context() compile bug
    watchdog: qcom: Avoid context switch in restart handler
    watchdog: coh901327: add COMMON_CLK dependency
    clk: ti: Fix memleak in ti_fapll_synth_setup
    pwm: zx: Add missing cleanup in error path
    pwm: lp3943: Dynamically allocate PWM chip base
    pwm: imx27: Fix overflow for bigger periods
    pwm: sun4i: Remove erroneous else branch
    io_uring: cancel only requests of current task
    tools build: Add missing libcap to test-all.bin target
    perf record: Fix memory leak when using '--user-regs=?' to list registers
    qlcnic: Fix error code in probe
    nfp: move indirect block cleanup to flower app stop callback
    vdpa/mlx5: Use write memory barrier after updating CQ index
    virtio_ring: Cut and paste bugs in vring_create_virtqueue_packed()
    virtio_net: Fix error code in probe()
    virtio_ring: Fix two use after free bugs
    vhost scsi: fix error return code in vhost_scsi_set_endpoint()
    epoll: check for events when removing a timed out thread from the wait queue
    clk: bcm: dvp: Add MODULE_DEVICE_TABLE()
    clk: at91: sama7g5: fix compilation error
    clk: at91: sam9x60: remove atmel,osc-bypass support
    clk: s2mps11: Fix a resource leak in error handling paths in the probe function
    clk: sunxi-ng: Make sure divider tables have sentinel
    clk: vc5: Use "idt,voltage-microvolt" instead of "idt,voltage-microvolts"
    kconfig: fix return value of do_error_if()
    powerpc/boot: Fix build of dts/fsl
    powerpc/smp: Add __init to init_big_cores()
    ARM: 9044/1: vfp: use undef hook for VFP support detection
    ARM: 9036/1: uncompress: Fix dbgadtb size parameter name
    perf probe: Fix memory leak when synthesizing SDT probes
    io_uring: fix racy IOPOLL flush overflow
    io_uring: cancel reqs shouldn't kill overflow list
    Smack: Handle io_uring kernel thread privileges
    proc mountinfo: make splice available again
    io_uring: fix io_cqring_events()'s noflush
    io_uring: fix racy IOPOLL completions
    io_uring: always let io_iopoll_complete() complete polled io
    vfio/pci: Move dummy_resources_list init in vfio_pci_probe()
    vfio/pci/nvlink2: Do not attempt NPU2 setup on POWER8NVL NPU
    media: gspca: Fix memory leak in probe
    io_uring: fix io_wqe->work_list corruption
    io_uring: fix 0-iov read buffer select
    io_uring: hold uring_lock while completing failed polled io in io_wq_submit_work()
    io_uring: fix ignoring xa_store errors
    io_uring: fix double io_uring free
    io_uring: make ctx cancel on exit targeted to actual ctx
    media: sunxi-cir: ensure IR is handled when it is continuous
    media: netup_unidvb: Don't leak SPI master in probe error path
    media: ipu3-cio2: Remove traces of returned buffers
    media: ipu3-cio2: Return actual subdev format
    media: ipu3-cio2: Serialise access to pad format
    media: ipu3-cio2: Validate mbus format in setting subdev format
    media: ipu3-cio2: Make the field on subdev format V4L2_FIELD_NONE
    Input: cyapa_gen6 - fix out-of-bounds stack access
    ALSA: hda/ca0132 - Change Input Source enum strings.
    ACPI: NFIT: Fix input validation of bus-family
    PM: ACPI: PCI: Drop acpi_pm_set_bridge_wakeup()
    Revert "ACPI / resources: Use AE_CTRL_TERMINATE to terminate resources walks"
    ACPI: PNP: compare the string length in the matching_id()
    ALSA: hda: Fix regressions on clear and reconfig sysfs
    ALSA: hda/ca0132 - Fix AE-5 rear headphone pincfg.
    ALSA: hda/realtek: make bass spk volume adjustable on a yoga laptop
    ALSA: hda/realtek - Enable headset mic of ASUS X430UN with ALC256
    ALSA: hda/realtek - Enable headset mic of ASUS Q524UQK with ALC255
    ALSA: hda/realtek - Add supported for more Lenovo ALC285 Headset Button
    ALSA: pcm: oss: Fix a few more UBSAN fixes
    ALSA/hda: apply jack fixup for the Acer Veriton N4640G/N6640G/N2510G
    ALSA: hda/realtek: Add quirk for MSI-GP73
    ALSA: hda/realtek: Apply jack fixup for Quanta NL3
    ALSA: hda/realtek: Remove dummy lineout on Acer TravelMate P648/P658
    ALSA: hda/realtek - Supported Dell fixed type headset
    ALSA: usb-audio: Add VID to support native DSD reproduction on FiiO devices
    ALSA: usb-audio: Disable sample read check if firmware doesn't give back
    ALSA: usb-audio: Add alias entry for ASUS PRIME TRX40 PRO-S
    ALSA: core: memalloc: add page alignment for iram
    s390/smp: perform initial CPU reset also for SMT siblings
    s390/kexec_file: fix diag308 subcode when loading crash kernel
    s390/idle: add missing mt_cycles calculation
    s390/idle: fix accounting with machine checks
    s390/dasd: fix hanging device offline processing
    s390/dasd: prevent inconsistent LCU device data
    s390/dasd: fix list corruption of pavgroup group list
    s390/dasd: fix list corruption of lcu list
    binder: add flag to clear buffer on txn complete
    ASoC: cx2072x: Fix doubly definitions of Playback and Capture streams
    ASoC: AMD Renoir - add DMI table to avoid the ACP mic probe (broken BIOS)
    ASoC: AMD Raven/Renoir - fix the PCI probe (PCI revision)
    staging: comedi: mf6x4: Fix AI end-of-conversion detection
    z3fold: simplify freeing slots
    z3fold: stricter locking and more careful reclaim
    perf/x86/intel: Add event constraint for CYCLE_ACTIVITY.STALLS_MEM_ANY
    perf/x86/intel: Fix rtm_abort_event encoding on Ice Lake
    perf/x86/intel/lbr: Fix the return type of get_lbr_cycles()
    powerpc/perf: Exclude kernel samples while counting events in user space.
    cpufreq: intel_pstate: Use most recent guaranteed performance values
    crypto: ecdh - avoid unaligned accesses in ecdh_set_secret()
    crypto: arm/aes-ce - work around Cortex-A57/A72 silion errata
    m68k: Fix WARNING splat in pmac_zilog driver
    Documentation: seqlock: s/LOCKTYPE/LOCKNAME/g
    EDAC/i10nm: Use readl() to access MMIO registers
    EDAC/amd64: Fix PCI component registration
    cpuset: fix race between hotplug work and later CPU offline
    dyndbg: fix use before null check
    USB: serial: mos7720: fix parallel-port state restore
    USB: serial: digi_acceleport: fix write-wakeup deadlocks
    USB: serial: keyspan_pda: fix dropped unthrottle interrupts
    USB: serial: keyspan_pda: fix write deadlock
    USB: serial: keyspan_pda: fix stalled writes
    USB: serial: keyspan_pda: fix write-wakeup use-after-free
    USB: serial: keyspan_pda: fix tx-unthrottle use-after-free
    USB: serial: keyspan_pda: fix write unthrottling
    btrfs: do not shorten unpin len for caching block groups
    btrfs: update last_byte_to_unpin in switch_commit_roots
    btrfs: fix race when defragmenting leads to unnecessary IO
    ext4: fix an IS_ERR() vs NULL check
    ext4: fix a memory leak of ext4_free_data
    ext4: fix deadlock with fs freezing and EA inodes
    ext4: don't remount read-only with errors=continue on reboot
    RISC-V: Fix usage of memblock_enforce_memory_limit
    arm64: dts: ti: k3-am65: mark dss as dma-coherent
    arm64: dts: marvell: keep SMMU disabled by default for Armada 7040 and 8040
    KVM: arm64: Introduce handling of AArch32 TTBCR2 traps
    KVM: x86: reinstate vendor-agnostic check on SPEC_CTRL cpuid bits
    KVM: SVM: Remove the call to sev_platform_status() during setup
    iommu/arm-smmu: Allow implementation specific write_s2cr
    iommu/arm-smmu-qcom: Read back stream mappings
    iommu/arm-smmu-qcom: Implement S2CR quirk
    ARM: dts: pandaboard: fix pinmux for gpio user button of Pandaboard ES
    ARM: dts: at91: sama5d2: fix CAN message ram offset and size
    ARM: tegra: Populate OPP table for Tegra20 Ventana
    xprtrdma: Fix XDRBUF_SPARSE_PAGES support
    powerpc/32: Fix vmap stack - Properly set r1 before activating MMU on syscall too
    powerpc: Fix incorrect stw{, ux, u, x} instructions in __set_pte_at
    powerpc/rtas: Fix typo of ibm,open-errinjct in RTAS filter
    powerpc/bitops: Fix possible undefined behaviour with fls() and fls64()
    powerpc/feature: Add CPU_FTR_NOEXECUTE to G2_LE
    powerpc/xmon: Change printk() to pr_cont()
    powerpc/8xx: Fix early debug when SMC1 is relocated
    powerpc/mm: Fix verification of MMU_FTR_TYPE_44x
    powerpc/powernv/npu: Do not attempt NPU2 setup on POWER8NVL NPU
    powerpc/powernv/memtrace: Don't leak kernel memory to user space
    powerpc/powernv/memtrace: Fix crashing the kernel when enabling concurrently
    ovl: make ioctl() safe
    ima: Don't modify file descriptor mode on the fly
    um: Remove use of asprinf in umid.c
    um: Fix time-travel mode
    ceph: fix race in concurrent __ceph_remove_cap invocations
    SMB3: avoid confusing warning message on mount to Azure
    SMB3.1.1: remove confusing mount warning when no SPNEGO info on negprot rsp
    SMB3.1.1: do not log warning message if server doesn't populate salt
    ubifs: wbuf: Don't leak kernel memory to flash
    jffs2: Fix GC exit abnormally
    jffs2: Fix ignoring mounting options problem during remounting
    fsnotify: generalize handle_inode_event()
    inotify: convert to handle_inode_event() interface
    fsnotify: fix events reported to watching parent and child
    jfs: Fix array index bounds check in dbAdjTree
    drm/panfrost: Fix job timeout handling
    drm/panfrost: Move the GPU reset bits outside the timeout handler
    platform/x86: mlx-platform: remove an unused variable
    drm/amdgpu: only set DP subconnector type on DP and eDP connectors
    drm/amd/display: Fix memory leaks in S3 resume
    drm/dp_aux_dev: check aux_dev before use in drm_dp_aux_dev_get_by_minor()
    drm/i915: Fix mismatch between misplaced vma check and vma insert
    iio: ad_sigma_delta: Don't put SPI transfer buffer on the stack
    spi: pxa2xx: Fix use-after-free on unbind
    spi: spi-sh: Fix use-after-free on unbind
    spi: atmel-quadspi: Fix use-after-free on unbind
    spi: spi-mtk-nor: Don't leak SPI master in probe error path
    spi: ar934x: Don't leak SPI master in probe error path
    spi: davinci: Fix use-after-free on unbind
    spi: fsl: fix use of spisel_boot signal on MPC8309
    spi: gpio: Don't leak SPI master in probe error path
    spi: mxic: Don't leak SPI master in probe error path
    spi: npcm-fiu: Disable clock in probe error path
    spi: pic32: Don't leak DMA channels in probe error path
    spi: rb4xx: Don't leak SPI master in probe error path
    spi: rpc-if: Fix use-after-free on unbind
    spi: sc18is602: Don't leak SPI master in probe error path
    spi: spi-geni-qcom: Fix use-after-free on unbind
    spi: spi-qcom-qspi: Fix use-after-free on unbind
    spi: st-ssc4: Fix unbalanced pm_runtime_disable() in probe error path
    spi: synquacer: Disable clock in probe error path
    spi: mt7621: Disable clock in probe error path
    spi: mt7621: Don't leak SPI master in probe error path
    spi: atmel-quadspi: Disable clock in probe error path
    spi: atmel-quadspi: Fix AHB memory accesses
    soc: qcom: smp2p: Safely acquire spinlock without IRQs
    mtd: spinand: Fix OOB read
    mtd: parser: cmdline: Fix parsing of part-names with colons
    mtd: core: Fix refcounting for unpartitioned MTDs
    mtd: rawnand: qcom: Fix DMA sync on FLASH_STATUS register read
    mtd: rawnand: meson: fix meson_nfc_dma_buffer_release() arguments
    scsi: qla2xxx: Fix crash during driver load on big endian machines
    scsi: lpfc: Fix invalid sleeping context in lpfc_sli4_nvmet_alloc()
    scsi: lpfc: Fix scheduling call while in softirq context in lpfc_unreg_rpi
    scsi: lpfc: Re-fix use after free in lpfc_rq_buf_free()
    openat2: reject RESOLVE_BENEATH|RESOLVE_IN_ROOT
    iio: buffer: Fix demux update
    iio: adc: rockchip_saradc: fix missing clk_disable_unprepare() on error in rockchip_saradc_resume
    iio: imu: st_lsm6dsx: fix edge-trigger interrupts
    iio:light:rpr0521: Fix timestamp alignment and prevent data leak.
    iio:light:st_uvis25: Fix timestamp alignment and prevent data leak.
    iio:magnetometer:mag3110: Fix alignment and data leak issues.
    iio:pressure:mpl3115: Force alignment of buffer
    iio:imu:bmi160: Fix too large a buffer.
    iio:imu:bmi160: Fix alignment and data leak issues
    iio:adc:ti-ads124s08: Fix buffer being too long.
    iio:adc:ti-ads124s08: Fix alignment and data leak issues.
    md/cluster: block reshape with remote resync job
    md/cluster: fix deadlock when node is doing resync job
    pinctrl: sunxi: Always call chained_irq_{enter, exit} in sunxi_pinctrl_irq_handler
    clk: ingenic: Fix divider calculation with div tables
    clk: mvebu: a3700: fix the XTAL MODE pin to MPP1_9
    clk: tegra: Do not return 0 on failure
    counter: microchip-tcb-capture: Fix CMR value check
    device-dax/core: Fix memory leak when rmmod dax.ko
    dma-buf/dma-resv: Respect num_fences when initializing the shared fence list.
    driver: core: Fix list corruption after device_del()
    xen-blkback: set ring->xenblkd to NULL after kthread_stop()
    xen/xenbus: Allow watches discard events before queueing
    xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()
    xen/xenbus/xen_bus_type: Support will_handle watch callback
    xen/xenbus: Count pending messages for each watch
    xenbus/xenbus_backend: Disallow pending watch messages
    memory: jz4780_nemc: Fix an error pointer vs NULL check in probe()
    memory: renesas-rpc-if: Fix a node reference leak in rpcif_probe()
    memory: renesas-rpc-if: Return correct value to the caller of rpcif_manual_xfer()
    memory: renesas-rpc-if: Fix unbalanced pm_runtime_enable in rpcif_{enable,disable}_rpm
    libnvdimm/namespace: Fix reaping of invalidated block-window-namespace labels
    platform/x86: intel-vbtn: Allow switch events on Acer Switch Alpha 12
    tracing: Disable ftrace selftests when any tracer is running
    mt76: add back the SUPPORTS_REORDERING_BUFFER flag
    of: fix linker-section match-table corruption
    PCI: Fix pci_slot_release() NULL pointer dereference
    regulator: axp20x: Fix DLDO2 voltage control register mask for AXP22x
    remoteproc: sysmon: Ensure remote notification ordering
    thermal/drivers/cpufreq_cooling: Update cpufreq_state only if state has changed
    rtc: ep93xx: Fix NULL pointer dereference in ep93xx_rtc_read_time
    Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"
    null_blk: Fix zone size initialization
    null_blk: Fail zone append to conventional zones
    drm/edid: fix objtool warning in drm_cvt_modes()
    x86/CPU/AMD: Save AMD NodeId as cpu_die_id
    Linux 5.10.4

    Signed-off-by: Greg Kroah-Hartman
    Change-Id: I25209e79d8b9faf5382087955a29b7404bdefe38

    Greg Kroah-Hartman
     
  • [ Upstream commit 289caf5d8f6c61c6d2b7fd752a7f483cd153f182 ]

    Patch series "simplify ep_poll".

    This patch series is a followup based on the suggestions and feedback by
    Linus:
    https://lkml.kernel.org/r/CAHk-=wizk=OxUyQPbO8MS41w2Pag1kniUV5WdD5qWL-gq1kjDA@mail.gmail.com

    The first patch in the series is a fix for the epoll race in presence of
    timeouts, so that it can be cleanly backported to all affected stable
    kernels.

    The rest of the patch series simplify the ep_poll() implementation. Some
    of these simplifications result in minor performance enhancements as well.
    We have kept these changes under self tests and internal benchmarks for a
    few days, and there are minor (1-2%) performance enhancements as a result.

    This patch (of 8):

    After abc610e01c66 ("fs/epoll: avoid barrier after an epoll_wait(2)
    timeout"), we break out of the ep_poll loop upon timeout, without checking
    whether there is any new events available. Prior to that patch-series we
    always called ep_events_available() after exiting the loop.

    This can cause races and missed wakeups. For example, consider the
    following scenario reported by Guantao Liu:

    Suppose we have an eventfd added using EPOLLET to an epollfd.

    Thread 1: Sleeps for just below 5ms and then writes to an eventfd.
    Thread 2: Calls epoll_wait with a timeout of 5 ms. If it sees an
    event of the eventfd, it will write back on that fd.
    Thread 3: Calls epoll_wait with a negative timeout.

    Prior to abc610e01c66, it is guaranteed that Thread 3 will wake up either
    by Thread 1 or Thread 2. After abc610e01c66, Thread 3 can be blocked
    indefinitely if Thread 2 sees a timeout right before the write to the
    eventfd by Thread 1. Thread 2 will be woken up from
    schedule_hrtimeout_range and, with evail 0, it will not call
    ep_send_events().

    To fix this issue:
    1) Simplify the timed_out case as suggested by Linus.
    2) while holding the lock, recheck whether the thread was woken up
    after its time out has reached.

    Note that (2) is different from Linus' original suggestion: It do not set
    "eavail = ep_events_available(ep)" to avoid unnecessary contention (when
    there are too many timed-out threads and a small number of events), as
    well as races mentioned in the discussion thread.

    This is the first patch in the series so that the backport to stable
    releases is straightforward.

    Link: https://lkml.kernel.org/r/20201106231635.3528496-1-soheil.kdev@gmail.com
    Link: https://lkml.kernel.org/r/CAHk-=wizk=OxUyQPbO8MS41w2Pag1kniUV5WdD5qWL-gq1kjDA@mail.gmail.com
    Link: https://lkml.kernel.org/r/20201106231635.3528496-2-soheil.kdev@gmail.com
    Fixes: abc610e01c66 ("fs/epoll: avoid barrier after an epoll_wait(2) timeout")
    Signed-off-by: Soheil Hassas Yeganeh
    Tested-by: Guantao Liu
    Suggested-by: Linus Torvalds
    Reported-by: Guantao Liu
    Reviewed-by: Eric Dumazet
    Reviewed-by: Willem de Bruijn
    Reviewed-by: Khazhismel Kumykov
    Reviewed-by: Davidlohr Bueso
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds
    Signed-off-by: Sasha Levin

    Soheil Hassas Yeganeh
     

06 Oct, 2020

1 commit


25 Sep, 2020

1 commit


11 Sep, 2020

1 commit

  • Checking for the lack of epitems refering to the epoll we want to insert into
    is not enough; we might have an insertion of that epoll into another one that
    has already collected the set of files to recheck for excessive reverse paths,
    but hasn't gotten to creating/inserting the epitem for it.

    However, any such insertion in progress can be detected - it will update the
    generation count in our epoll when it's done looking through it for files
    to check. That gets done under ->mtx of our epoll and that allows us to
    detect that safely.

    We are *not* holding epmutex here, so the generation count is not stable.
    However, since both the update of ep->gen by loop check and (later)
    insertion into ->f_ep_link are done with ep->mtx held, we are fine -
    the sequence is
    grab epmutex
    bump loop_check_gen
    ...
    grab tep->mtx // 1
    tep->gen = loop_check_gen
    ...
    drop tep->mtx // 2
    ...
    grab tep->mtx // 3
    ...
    insert into ->f_ep_link
    ...
    drop tep->mtx // 4
    bump loop_check_gen
    drop epmutex
    and if the fastpath check in another thread happens for that
    eventpoll, it can come
    * before (1) - in that case fastpath is just fine
    * after (4) - we'll see non-empty ->f_ep_link, slow path
    taken
    * between (2) and (3) - loop_check_gen is stable,
    with ->mtx providing barriers and we end up taking slow path.

    Note that ->f_ep_link emptiness check is slightly racy - we are protected
    against insertions into that list, but removals can happen right under us.
    Not a problem - in the worst case we'll end up taking a slow path for
    no good reason.

    Signed-off-by: Al Viro

    Al Viro
     

10 Sep, 2020

2 commits


07 Sep, 2020

1 commit


02 Sep, 2020

1 commit


24 Aug, 2020

1 commit


23 Aug, 2020

2 commits

  • Signed-off-by: Al Viro

    Al Viro
     
  • When adding a new fd to an epoll, and that this new fd is an
    epoll fd itself, we recursively scan the fds attached to it
    to detect cycles, and add non-epool files to a "check list"
    that gets subsequently parsed.

    However, this check list isn't completely safe when deletions
    can happen concurrently. To sidestep the issue, make sure that
    a struct file placed on the check list sees its f_count increased,
    ensuring that a concurrent deletion won't result in the file
    disapearing from under our feet.

    Cc: stable@vger.kernel.org
    Signed-off-by: Marc Zyngier
    Signed-off-by: Al Viro

    Marc Zyngier
     

18 May, 2020

1 commit


15 May, 2020

1 commit

  • There is a possible race when ep_scan_ready_list() leaves ->rdllist and
    ->obflist empty for a short period of time although some events are
    pending. It is quite likely that ep_events_available() observes empty
    lists and goes to sleep.

    Since commit 339ddb53d373 ("fs/epoll: remove unnecessary wakeups of
    nested epoll") we are conservative in wakeups (there is only one place
    for wakeup and this is ep_poll_callback()), thus ep_events_available()
    must always observe correct state of two lists.

    The easiest and correct way is to do the final check under the lock.
    This does not impact the performance, since lock is taken anyway for
    adding a wait entry to the wait queue.

    The discussion of the problem can be found here:

    https://lore.kernel.org/linux-fsdevel/a2f22c3c-c25a-4bda-8339-a7bdaf17849e@akamai.com/

    In this patch barrierless __set_current_state() is used. This is safe
    since waitqueue_active() is called under the same lock on wakeup side.

    Short-circuit for fatal signals (i.e. fatal_signal_pending() check) is
    moved to the line just before actual events harvesting routine. This is
    fully compliant to what is said in the comment of the patch where the
    actual fatal_signal_pending() check was added: c257a340ede0 ("fs, epoll:
    short circuit fetching events if thread has been killed").

    Fixes: 339ddb53d373 ("fs/epoll: remove unnecessary wakeups of nested epoll")
    Reported-by: Jason Baron
    Reported-by: Randy Dunlap
    Signed-off-by: Roman Penyaev
    Signed-off-by: Andrew Morton
    Reviewed-by: Jason Baron
    Cc: Khazhismel Kumykov
    Cc: Alexander Viro
    Cc:
    Link: http://lkml.kernel.org/r/20200505145609.1865152-1-rpenyaev@suse.de
    Signed-off-by: Linus Torvalds

    Roman Penyaev
     

11 May, 2020

1 commit


08 May, 2020

2 commits

  • This patch does two things:

    - fixes a lost wakeup introduced by commit 339ddb53d373 ("fs/epoll:
    remove unnecessary wakeups of nested epoll")

    - improves performance for events delivery.

    The description of the problem is the following: if N (>1) threads are
    waiting on ep->wq for new events and M (>1) events come, it is quite
    likely that >1 wakeups hit the same wait queue entry, because there is
    quite a big window between __add_wait_queue_exclusive() and the
    following __remove_wait_queue() calls in ep_poll() function.

    This can lead to lost wakeups, because thread, which was woken up, can
    handle not all the events in ->rdllist. (in better words the problem is
    described here: https://lkml.org/lkml/2019/10/7/905)

    The idea of the current patch is to use init_wait() instead of
    init_waitqueue_entry().

    Internally init_wait() sets autoremove_wake_function as a callback,
    which removes the wait entry atomically (under the wq locks) from the
    list, thus the next coming wakeup hits the next wait entry in the wait
    queue, thus preventing lost wakeups.

    Problem is very well reproduced by the epoll60 test case [1].

    Wait entry removal on wakeup has also performance benefits, because
    there is no need to take a ep->lock and remove wait entry from the queue
    after the successful wakeup. Here is the timing output of the epoll60
    test case:

    With explicit wakeup from ep_scan_ready_list() (the state of the
    code prior 339ddb53d373):

    real 0m6.970s
    user 0m49.786s
    sys 0m0.113s

    After this patch:

    real 0m5.220s
    user 0m36.879s
    sys 0m0.019s

    The other testcase is the stress-epoll [2], where one thread consumes
    all the events and other threads produce many events:

    With explicit wakeup from ep_scan_ready_list() (the state of the
    code prior 339ddb53d373):

    threads events/ms run-time ms
    8 5427 1474
    16 6163 2596
    32 6824 4689
    64 7060 9064
    128 6991 18309

    After this patch:

    threads events/ms run-time ms
    8 5598 1429
    16 7073 2262
    32 7502 4265
    64 7640 8376
    128 7634 16767

    (number of "events/ms" represents event bandwidth, thus higher is
    better; number of "run-time ms" represents overall time spent
    doing the benchmark, thus lower is better)

    [1] tools/testing/selftests/filesystems/epoll/epoll_wakeup_test.c
    [2] https://github.com/rouming/test-tools/blob/master/stress-epoll.c

    Signed-off-by: Roman Penyaev
    Signed-off-by: Andrew Morton
    Reviewed-by: Jason Baron
    Cc: Khazhismel Kumykov
    Cc: Alexander Viro
    Cc: Heiher
    Cc:
    Link: http://lkml.kernel.org/r/20200430130326.1368509-2-rpenyaev@suse.de
    Signed-off-by: Linus Torvalds

    Roman Penyaev
     
  • In the event that we add to ovflist, before commit 339ddb53d373
    ("fs/epoll: remove unnecessary wakeups of nested epoll") we would be
    woken up by ep_scan_ready_list, and did no wakeup in ep_poll_callback.

    With that wakeup removed, if we add to ovflist here, we may never wake
    up. Rather than adding back the ep_scan_ready_list wakeup - which was
    resulting in unnecessary wakeups, trigger a wake-up in ep_poll_callback.

    We noticed that one of our workloads was missing wakeups starting with
    339ddb53d373 and upon manual inspection, this wakeup seemed missing to me.
    With this patch added, we no longer see missing wakeups. I haven't yet
    tried to make a small reproducer, but the existing kselftests in
    filesystem/epoll passed for me with this patch.

    [khazhy@google.com: use if/elif instead of goto + cleanup suggested by Roman]
    Link: http://lkml.kernel.org/r/20200424190039.192373-1-khazhy@google.com
    Fixes: 339ddb53d373 ("fs/epoll: remove unnecessary wakeups of nested epoll")
    Signed-off-by: Khazhismel Kumykov
    Signed-off-by: Andrew Morton
    Reviewed-by: Roman Penyaev
    Cc: Alexander Viro
    Cc: Roman Penyaev
    Cc: Heiher
    Cc: Jason Baron
    Cc:
    Link: http://lkml.kernel.org/r/20200424025057.118641-1-khazhy@google.com
    Signed-off-by: Linus Torvalds

    Khazhismel Kumykov
     

10 Apr, 2020

1 commit


08 Apr, 2020

1 commit

  • Davidlohr Bueso pointed out that when CONFIG_DEBUG_LOCK_ALLOC is set
    ep_poll_safewake() can take several non-raw spinlocks after disabling
    interrupts. Since a spinlock can block in the -rt kernel, we can't take a
    spinlock after disabling interrupts. So let's re-work how we determine
    the nesting level such that it plays nicely with the -rt kernel.

    Let's introduce a 'nests' field in struct eventpoll that records the
    current nesting level during ep_poll_callback(). Then, if we nest again
    we can find the previous struct eventpoll that we were called from and
    increase our count by 1. The 'nests' field is protected by
    ep->poll_wait.lock.

    I've also moved the visited field to reduce the size of struct eventpoll
    from 184 bytes to 176 bytes on x86_64 for !CONFIG_DEBUG_LOCK_ALLOC, which
    is typical for a production config.

    Reported-by: Davidlohr Bueso
    Signed-off-by: Jason Baron
    Signed-off-by: Andrew Morton
    Reviewed-by: Davidlohr Bueso
    Cc: Roman Penyaev
    Cc: Eric Wong
    Cc: Al Viro
    Link: http://lkml.kernel.org/r/1582739816-13167-1-git-send-email-jbaron@akamai.com
    Signed-off-by: Linus Torvalds

    Jason Baron
     

23 Mar, 2020

1 commit


22 Mar, 2020

1 commit

  • This fixes possible lost wakeup introduced by commit a218cc491420.
    Originally modifications to ep->wq were serialized by ep->wq.lock, but
    in commit a218cc491420 ("epoll: use rwlock in order to reduce
    ep_poll_callback() contention") a new rw lock was introduced in order to
    relax fd event path, i.e. callers of ep_poll_callback() function.

    After the change ep_modify and ep_insert (both are called on epoll_ctl()
    path) were switched to ep->lock, but ep_poll (epoll_wait) was using
    ep->wq.lock on wqueue list modification.

    The bug doesn't lead to any wqueue list corruptions, because wake up
    path and list modifications were serialized by ep->wq.lock internally,
    but actual waitqueue_active() check prior wake_up() call can be
    reordered with modifications of ep ready list, thus wake up can be lost.

    And yes, can be healed by explicit smp_mb():

    list_add_tail(&epi->rdlink, &ep->rdllist);
    smp_mb();
    if (waitqueue_active(&ep->wq))
    wake_up(&ep->wp);

    But let's make it simple, thus current patch replaces ep->wq.lock with
    the ep->lock for wqueue modifications, thus wake up path always observes
    activeness of the wqueue correcty.

    Fixes: a218cc491420 ("epoll: use rwlock in order to reduce ep_poll_callback() contention")
    Reported-by: Max Neunhoeffer
    Signed-off-by: Roman Penyaev
    Signed-off-by: Andrew Morton
    Tested-by: Max Neunhoeffer
    Cc: Jakub Kicinski
    Cc: Christopher Kohlhoff
    Cc: Davidlohr Bueso
    Cc: Jason Baron
    Cc: Jes Sorensen
    Cc: [5.1+]
    Link: http://lkml.kernel.org/r/20200214170211.561524-1-rpenyaev@suse.de
    References: https://bugzilla.kernel.org/show_bug.cgi?id=205933
    Bisected-by: Max Neunhoeffer
    Signed-off-by: Linus Torvalds

    Roman Penyaev
     

03 Feb, 2020

1 commit


30 Jan, 2020

2 commits


09 Dec, 2019

1 commit


05 Dec, 2019

2 commits

  • Take the case where we have:

    t0
    | (ew)
    e0
    | (et)
    e1
    | (lt)
    s0

    t0: thread 0
    e0: epoll fd 0
    e1: epoll fd 1
    s0: socket fd 0
    ew: epoll_wait
    et: edge-trigger
    lt: level-trigger

    We remove unnecessary wakeups to prevent the nested epoll that working in edge-
    triggered mode to waking up continuously.

    Test code:
    #include
    #include
    #include

    int main(int argc, char *argv[])
    {
    int sfd[2];
    int efd[2];
    struct epoll_event e;

    if (socketpair(AF_UNIX, SOCK_STREAM, 0, sfd) < 0)
    goto out;

    efd[0] = epoll_create(1);
    if (efd[0] < 0)
    goto out;

    efd[1] = epoll_create(1);
    if (efd[1] < 0)
    goto out;

    e.events = EPOLLIN;
    if (epoll_ctl(efd[1], EPOLL_CTL_ADD, sfd[0], &e) < 0)
    goto out;

    e.events = EPOLLIN | EPOLLET;
    if (epoll_ctl(efd[0], EPOLL_CTL_ADD, efd[1], &e) < 0)
    goto out;

    if (write(sfd[1], "w", 1) != 1)
    goto out;

    if (epoll_wait(efd[0], &e, 1, 0) != 1)
    goto out;

    if (epoll_wait(efd[0], &e, 1, 0) != 0)
    goto out;

    close(efd[0]);
    close(efd[1]);
    close(sfd[0]);
    close(sfd[1]);

    return 0;

    out:
    return -1;
    }

    More tests:
    https://github.com/heiher/epoll-wakeup

    Link: http://lkml.kernel.org/r/20191009060516.3577-1-r@hev.cc
    Signed-off-by: hev
    Reviewed-by: Roman Penyaev
    Cc: Al Viro
    Cc: Davide Libenzi
    Cc: Davidlohr Bueso
    Cc: Dominik Brodowski
    Cc: Eric Wong
    Cc: Jason Baron
    Cc: Sridhar Samudrala
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Heiher
     
  • Currently, ep_poll_safewake() in the CONFIG_DEBUG_LOCK_ALLOC case uses
    ep_call_nested() in order to pass the correct subclass argument to
    spin_lock_irqsave_nested(). However, ep_call_nested() adds unnecessary
    checks for epoll depth and loops that are already verified when doing
    EPOLL_CTL_ADD. This mirrors a conversion that was done for
    !CONFIG_DEBUG_LOCK_ALLOC in: commit 37b5e5212a44 ("epoll: remove
    ep_call_nested() from ep_eventpoll_poll()")

    Link: http://lkml.kernel.org/r/1567628549-11501-1-git-send-email-jbaron@akamai.com
    Signed-off-by: Jason Baron
    Reviewed-by: Roman Penyaev
    Cc: Davidlohr Bueso
    Cc: Al Viro
    Cc: Eric Wong
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jason Baron
     

21 Sep, 2019

1 commit

  • This merges Linus's tree as of commit b41dae061bbd ("Merge tag
    'xfs-5.4-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux")
    into android-mainline.

    This "early" merge makes it easier to test and handle merge conflicts
    instead of having to wait until the "end" of the merge window and handle
    all 10000+ commits at once.

    Signed-off-by: Greg Kroah-Hartman
    Change-Id: I6bebf55e5e2353f814e3c87f5033607b1ae5d812

    Greg Kroah-Hartman
     

21 Aug, 2019

1 commit

  • Add an ID and a device pointer to 'struct wakeup_source'. Use them to to
    expose wakeup sources statistics in sysfs under
    /sys/class/wakeup/wakeup/*.

    Co-developed-by: Greg Kroah-Hartman
    Signed-off-by: Greg Kroah-Hartman
    Co-developed-by: Stephen Boyd
    Signed-off-by: Stephen Boyd
    Signed-off-by: Tri Vo
    Tested-by: Kalesh Singh
    Signed-off-by: Rafael J. Wysocki

    Tri Vo
     

24 Jul, 2019

1 commit


19 Jul, 2019

1 commit

  • In the sysctl code the proc_dointvec_minmax() function is often used to
    validate the user supplied value between an allowed range. This
    function uses the extra1 and extra2 members from struct ctl_table as
    minimum and maximum allowed value.

    On sysctl handler declaration, in every source file there are some
    readonly variables containing just an integer which address is assigned
    to the extra1 and extra2 members, so the sysctl range is enforced.

    The special values 0, 1 and INT_MAX are very often used as range
    boundary, leading duplication of variables like zero=0, one=1,
    int_max=INT_MAX in different source files:

    $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l
    248

    Add a const int array containing the most commonly used values, some
    macros to refer more easily to the correct array member, and use them
    instead of creating a local one for every object file.

    This is the bloat-o-meter output comparing the old and new binary
    compiled with the default Fedora config:

    # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o
    add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164)
    Data old new delta
    sysctl_vals - 12 +12
    __kstrtab_sysctl_vals - 12 +12
    max 14 10 -4
    int_max 16 - -16
    one 68 - -68
    zero 128 28 -100
    Total: Before=20583249, After=20583085, chg -0.00%

    [mcroce@redhat.com: tipc: remove two unused variables]
    Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com
    [akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c]
    [arnd@arndb.de: proc/sysctl: make firmware loader table conditional]
    Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de
    [akpm@linux-foundation.org: fix fs/eventpoll.c]
    Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com
    Signed-off-by: Matteo Croce
    Signed-off-by: Arnd Bergmann
    Acked-by: Kees Cook
    Reviewed-by: Aaron Tomlin
    Cc: Matthew Wilcox
    Cc: Stephen Rothwell
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Matteo Croce
     

17 Jul, 2019

1 commit

  • task->saved_sigmask and ->restore_sigmask are only used in the ret-from-
    syscall paths. This means that set_user_sigmask() can save ->blocked in
    ->saved_sigmask and do set_restore_sigmask() to indicate that ->blocked
    was modified.

    This way the callers do not need 2 sigset_t's passed to set/restore and
    restore_user_sigmask() renamed to restore_saved_sigmask_unless() turns
    into the trivial helper which just calls restore_saved_sigmask().

    Link: http://lkml.kernel.org/r/20190606113206.GA9464@redhat.com
    Signed-off-by: Oleg Nesterov
    Cc: Deepa Dinamani
    Cc: Arnd Bergmann
    Cc: Jens Axboe
    Cc: Davidlohr Bueso
    Cc: Eric Wong
    Cc: Jason Baron
    Cc: Thomas Gleixner
    Cc: Al Viro
    Cc: Eric W. Biederman
    Cc: David Laight
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Oleg Nesterov
     

03 Jul, 2019

1 commit


29 Jun, 2019

1 commit

  • This is the minimal fix for stable, I'll send cleanups later.

    Commit 854a6ed56839 ("signal: Add restore_user_sigmask()") introduced
    the visible change which breaks user-space: a signal temporary unblocked
    by set_user_sigmask() can be delivered even if the caller returns
    success or timeout.

    Change restore_user_sigmask() to accept the additional "interrupted"
    argument which should be used instead of signal_pending() check, and
    update the callers.

    Eric said:

    : For clarity. I don't think this is required by posix, or fundamentally to
    : remove the races in select. It is what linux has always done and we have
    : applications who care so I agree this fix is needed.
    :
    : Further in any case where the semantic change that this patch rolls back
    : (aka where allowing a signal to be delivered and the select like call to
    : complete) would be advantage we can do as well if not better by using
    : signalfd.
    :
    : Michael is there any chance we can get this guarantee of the linux
    : implementation of pselect and friends clearly documented. The guarantee
    : that if the system call completes successfully we are guaranteed that no
    : signal that is unblocked by using sigmask will be delivered?

    Link: http://lkml.kernel.org/r/20190604134117.GA29963@redhat.com
    Fixes: 854a6ed56839a40f6b5d02a2962f48841482eec4 ("signal: Add restore_user_sigmask()")
    Signed-off-by: Oleg Nesterov
    Reported-by: Eric Wong
    Tested-by: Eric Wong
    Acked-by: "Eric W. Biederman"
    Acked-by: Arnd Bergmann
    Acked-by: Deepa Dinamani
    Cc: Michael Kerrisk
    Cc: Jens Axboe
    Cc: Davidlohr Bueso
    Cc: Jason Baron
    Cc: Thomas Gleixner
    Cc: Al Viro
    Cc: David Laight
    Cc: [5.0+]
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Oleg Nesterov
     

03 Jun, 2019

1 commit


31 May, 2019

1 commit

  • Based on 1 normalized pattern(s):

    this program is free software you can redistribute it and or modify
    it under the terms of the gnu general public license as published by
    the free software foundation either version 2 of the license or at
    your option any later version

    extracted by the scancode license scanner the SPDX license identifier

    GPL-2.0-or-later

    has been chosen to replace the boilerplate/reference in 3029 file(s).

    Signed-off-by: Thomas Gleixner
    Reviewed-by: Allison Randal
    Cc: linux-spdx@vger.kernel.org
    Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
    Signed-off-by: Greg Kroah-Hartman

    Thomas Gleixner
     

04 May, 2019

2 commits

  • Change-Id: I4380c68c3474026a42ffa9f95c525f9a563ba7a3

    Todd Kjos
     
  • Avoid waking up every thread sleeping in an epoll_wait call during
    suspend and resume by calling a freezable blocking call. Previous
    patches modified the freezer to avoid sending wakeups to threads
    that are blocked in freezable blocking calls.

    This call was selected to be converted to a freezable call because
    it doesn't hold any locks or release any resources when interrupted
    that might be needed by another freezing task or a kernel driver
    during suspend, and is a common site where idle userspace tasks are
    blocked.

    Bug: 77139736
    Bug: 120440023
    Change-Id: I848d08d28c89302fd42bbbdfa76489a474ab27bf
    [ccross: This was upstream (https://lkml.org/lkml/2013/5/6/823), but
    reverted because it reportedly caused memory corruption on
    32-bit x86 (https://patchwork.kernel.org/patch/3162301/).]
    Acked-by: Tejun Heo
    Signed-off-by: Colin Cross
    Signed-off-by: Rafael J. Wysocki

    Colin Cross
     

08 Mar, 2019

2 commits

  • The goal of this patch is to reduce contention of ep_poll_callback()
    which can be called concurrently from different CPUs in case of high
    events rates and many fds per epoll. Problem can be very well
    reproduced by generating events (write to pipe or eventfd) from many
    threads, while consumer thread does polling. In other words this patch
    increases the bandwidth of events which can be delivered from sources to
    the poller by adding poll items in a lockless way to the list.

    The main change is in replacement of the spinlock with a rwlock, which
    is taken on read in ep_poll_callback(), and then by adding poll items to
    the tail of the list using xchg atomic instruction. Write lock is taken
    everywhere else in order to stop list modifications and guarantee that
    list updates are fully completed (I assume that write side of a rwlock
    does not starve, it seems qrwlock implementation has these guarantees).

    The following are some microbenchmark results based on the test [1]
    which starts threads which generate N events each. The test ends when
    all events are successfully fetched by the poller thread:

    spinlock
    ========

    threads events/ms run-time ms
    8 6402 12495
    16 7045 22709
    32 7395 43268

    rwlock + xchg
    =============

    threads events/ms run-time ms
    8 10038 7969
    16 12178 13138
    32 13223 24199

    According to the results bandwidth of delivered events is significantly
    increased, thus execution time is reduced.

    This patch was tested with different sort of microbenchmarks and
    artificial delays (e.g. "udelay(get_random_int() & 0xff)") introduced
    in kernel on paths where items are added to lists.

    [1] https://github.com/rouming/test-tools/blob/master/stress-epoll.c

    Link: http://lkml.kernel.org/r/20190103150104.17128-5-rpenyaev@suse.de
    Signed-off-by: Roman Penyaev
    Cc: Davidlohr Bueso
    Cc: Jason Baron
    Cc: Al Viro
    Cc: "Paul E. McKenney"
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Roman Penyaev
     
  • Original comment "Activate ep->ws since epi->ws may get deactivated at
    any time" indeed sounds loud, but it is incorrect, because the path
    where we check epi->ws is a path where insert to ovflist happens, i.e.
    ep_scan_ready_list() has taken ep->mtx and waits for this callback to
    finish, thus ep_modify() (which unregisters wakeup source) waits for
    ep_scan_ready_list().

    Here in this patch I simply call ep_pm_stay_awake_rcu(), which is a bit
    extra for this path (indirectly protected by main ep->mtx, so even rcu
    is not needed), but I do not want to create another naked
    __ep_pm_stay_awake() variant only for this particular case, so rcu variant
    is just better for all the cases.

    Link: http://lkml.kernel.org/r/20190103150104.17128-4-rpenyaev@suse.de
    Signed-off-by: Roman Penyaev
    Cc: Davidlohr Bueso
    Cc: Jason Baron
    Cc: Al Viro
    Cc: "Paul E. McKenney"
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Roman Penyaev