Pull KVM updates from Paolo Bonzini:
"ARM:
- support for SVE and Pointer Authentication in guests
- PMU improvements
POWER:
- support for direct access to the POWER9 XIVE interrupt controller
- memory and performance optimizations
x86:
- support for accessing memory not backed by struct page
- fixes and refactoring
Generic:
- dirty page tracking improvements"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (155 commits)
kvm: fix compilation on aarch64
Revert "KVM: nVMX: Expose RDPMC-exiting only when guest supports PMU"
kvm: x86: Fix L1TF mitigation for shadow MMU
KVM: nVMX: Disable intercept for FS/GS base MSRs in vmcs02 when possible
KVM: PPC: Book3S: Remove useless checks in 'release' method of KVM device
KVM: PPC: Book3S HV: XIVE: Fix spelling mistake "acessing" -> "accessing"
KVM: PPC: Book3S HV: Make sure to load LPID for radix VCPUs
kvm: nVMX: Set nested_run_pending in vmx_set_nested_state after checks complete
tests: kvm: Add tests for KVM_SET_NESTED_STATE
KVM: nVMX: KVM_SET_NESTED_STATE - Tear down old EVMCS state before setting new state
tests: kvm: Add tests for KVM_CAP_MAX_VCPUS and KVM_CAP_MAX_CPU_ID
tests: kvm: Add tests to .gitignore
KVM: Introduce KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
KVM: Fix kvm_clear_dirty_log_protect off-by-(minus-)one
KVM: Fix the bitmap range to copy during clear dirty
KVM: arm64: Fix ptrauth ID register masking logic
KVM: x86: use direct accessors for RIP and RSP
KVM: VMX: Use accessors for GPRs outside of dedicated caching logic
KVM: x86: Omit caching logic for always-available GPRs
kvm, x86: Properly check whether a pfn is an MMIO or not
...
Pull more s390 updates from Martin Schwidefsky:
- Enhancements for the QDIO layer
- Remove the RCP trace event
- Avoid three build issues
- Move the defconfig to the configs directory
* tag 's390-5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390: move arch/s390/defconfig to arch/s390/configs/defconfig
s390/qdio: optimize state inspection of HW-owned SBALs
s390/qdio: use get_buf_state() in debug_get_buf_state()
s390/qdio: allow to scan all Output SBALs in one go
s390/cio: Remove tracing for rchp instruction
s390/kasan: adapt disabled_wait usage to avoid build error
latent_entropy: avoid build error when plugin cflags are not set
s390/boot: fix compiler error due to missing awk strtonum
Pull more block updates from Jens Axboe:
"This is mainly some late lightnvm changes that came in just before the
merge window, as well as fixes that have been queued up since the
initial pull request was frozen.
This contains:
- lightnvm changes, fixing race conditions, improving memory
utilization, and improving pblk compatability (Chansol, Igor,
Marcin)
- NVMe pull request with minor fixes all over the map (via Christoph)
- remove redundant error print in sata_rcar (Geert)
- struct_size() cleanup (Jackie)
- dasd CONFIG_LBADF warning fix (Ming)
- brd cond_resched() improvement (Mikulas)"
* tag 'for-5.2/block-post-20190516' of git://git.kernel.dk/linux-block: (41 commits)
block/bio-integrity: use struct_size() in kmalloc()
nvme: validate cntlid during controller initialisation
nvme: change locking for the per-subsystem controller list
nvme: trace all async notice events
nvme: fix typos in nvme status code values
nvme-fabrics: remove unused argument
nvme-multipath: avoid crash on invalid subsystem cntlid enumeration
nvme-fc: use separate work queue to avoid warning
nvme-rdma: remove redundant reference between ib_device and tagset
nvme-pci: mark expected switch fall-through
nvme-pci: add known admin effects to augument admin effects log page
nvme-pci: init shadow doorbell after each reset
brd: add cond_resched to brd_free_pages
sata_rcar: Remove ata_host_alloc() error printing
s390/dasd: fix build warning in dasd_eckd_build_cp_raw
lightnvm: pblk: use nvm_rq_to_ppa_list()
lightnvm: pblk: simplify partial read path
lightnvm: do not remove instance under global lock
lightnvm: track inflight target creations
lightnvm: pblk: recover only written metadata
...
Pull more clk framework updates from Stephen Boyd:
"One more patch to remove io.h from clk-provider.h.
We used to need this include when we had clk_readl() and clk_writel(),
but those are gone now so this patch pushes the dependency out to the
users of clk-provider.h"
* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: Remove io.h from clk-provider.h
Pull misc AFS fixes from David Howells:
"This fixes a set of miscellaneous issues in the afs filesystem,
including:
- leak of keys on file close.
- broken error handling in xattr functions.
- missing locking when updating VL server list.
- volume location server DNS lookup whereby preloaded cells may not
ever get a lookup and regular DNS lookups to maintain server lists
consume power unnecessarily.
- incorrect error propagation and handling in the fileserver
iteration code causes operations to sometimes apparently succeed.
- interruption of server record check/update side op during
fileserver iteration causes uninterruptible main operations to fail
unexpectedly.
- callback promise expiry time miscalculation.
- over invalidation of the callback promise on directories.
- double locking on callback break waking up file locking waiters.
- double increment of the vnode callback break counter.
Note that it makes some changes outside of the afs code, including:
- an extra parameter to dns_query() to allow the dns_resolver key
just accessed to be immediately invalidated. AFS is caching the
results itself, so the key can be discarded.
- an interruptible version of wait_var_event().
- an rxrpc function to allow the maximum lifespan to be set on a
call.
- a way for an rxrpc call to be marked as non-interruptible"
* tag 'afs-fixes-20190516' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Fix double inc of vnode->cb_break
afs: Fix lock-wait/callback-break double locking
afs: Don't invalidate callback if AFS_VNODE_DIR_VALID not set
afs: Fix calculation of callback expiry time
afs: Make dynamic root population wait uninterruptibly for proc_cells_lock
afs: Make some RPC operations non-interruptible
rxrpc: Allow the kernel to mark a call as being non-interruptible
afs: Fix error propagation from server record check/update
afs: Fix the maximum lifespan of VL and probe calls
rxrpc: Provide kernel interface to set max lifespan on a call
afs: Fix "kAFS: AFS vnode with undefined type 0"
afs: Fix cell DNS lookup
Add wait_var_event_interruptible()
dns_resolver: Allow used keys to be invalidated
afs: Fix afs_cell records to always have a VL server list record
afs: Fix missing lock when replacing VL server list
afs: Fix afs_xattr_get_yfs() to not try freeing an error value
afs: Fix incorrect error handling in afs_xattr_get_acl()
afs: Fix key leak in afs_release() and afs_evict_inode()
Pull ceph updates from Ilya Dryomov:
"On the filesystem side we have:
- a fix to enforce quotas set above the mount point (Luis Henriques)
- support for exporting snapshots through NFS (Zheng Yan)
- proper statx implementation (Jeff Layton). statx flags are mapped
to MDS caps, with AT_STATX_{DONT,FORCE}_SYNC taken into account.
- some follow-up dentry name handling fixes, in particular
elimination of our hand-rolled helper and the switch to __getname()
as suggested by Al (Jeff Layton)
- a set of MDS client cleanups in preparation for async MDS requests
in the future (Jeff Layton)
- a fix to sync the filesystem before remounting (Jeff Layton)
On the rbd side, work is on-going on object-map and fast-diff image
features"
* tag 'ceph-for-5.2-rc1' of git://github.com/ceph/ceph-client: (29 commits)
ceph: flush dirty inodes before proceeding with remount
ceph: fix unaligned access in ceph_send_cap_releases
libceph: make ceph_pr_addr take an struct ceph_entity_addr pointer
libceph: fix unaligned accesses in ceph_entity_addr handling
rbd: don't assert on writes to snapshots
rbd: client_mutex is never nested
ceph: print inode number in __caps_issued_mask debugging messages
ceph: just call get_session in __ceph_lookup_mds_session
ceph: simplify arguments and return semantics of try_get_cap_refs
ceph: fix comment over ceph_drop_caps_for_unlink
ceph: move wait for mds request into helper function
ceph: have ceph_mdsc_do_request call ceph_mdsc_submit_request
ceph: after an MDS request, do callback and completions
ceph: use pathlen values returned by set_request_path_attr
ceph: use __getname/__putname in ceph_mdsc_build_path
ceph: use ceph_mdsc_build_path instead of clone_dentry_name
ceph: fix potential use-after-free in ceph_mdsc_build_path
ceph: dump granular cap info in "caps" debugfs file
ceph: make iterate_session_caps a public symbol
ceph: fix NULL pointer deref when debugging is enabled
...
Pull thermal management updates from Zhang Rui:
- Remove the 'module' Kconfig option for thermal subsystem framework
because the thermal framework are required to be ready as early as
possible to avoid overheat at boot time (Daniel Lezcano)
- Fix a bug that thermal framework pokes disabled thermal zones upon
resume (Wei Wang)
- A couple of cleanups and trivial fixes on int340x thermal drivers
(Srinivas Pandruvada, Zhang Rui, Sumeet Pawnikar)
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
drivers: thermal: processor_thermal: Downgrade error message
mlxsw: Remove obsolete dependency on THERMAL=m
hwmon/drivers/core: Simplify complex dependency
thermal/drivers/core: Fix typo in the option name
thermal/drivers/core: Remove depends on THERMAL in Kconfig
thermal/drivers/core: Remove module unload code
thermal/drivers/core: Remove the module Kconfig's option
thermal: core: skip update disabled thermal zones after suspend
thermal: make device_register's type argument const
thermal: intel: int340x: processor_thermal_device: simplify to get driver data
thermal/int3403_thermal: favor _TMP instead of PTYP
Pull device mapper updates from Mike Snitzer:
- Improve DM snapshot target's scalability by using finer grained
locking. Requires some list_bl interface improvements.
- Add ability for DM integrity to use a bitmap mode, that tracks
regions where data and metadata are out of sync, instead of using a
journal.
- Improve DM thin provisioning target to not write metadata changes to
disk if the thin-pool and associated thin devices are merely
activated but not used. This avoids metadata corruption due to
concurrent activation of thin devices across different OS instances
(e.g. split brain scenarios, which ultimately would be avoided if
proper device filters were used -- but not having proper filtering
has proven a very common configuration mistake)
- Fix missing call to path selector type->end_io in DM multipath. This
fixes reported performance problems due to inaccurate path selector
IO accounting causing an imbalance of IO (e.g. avoiding issuing IO to
particular path due to it seemingly being heavily used).
- Fix bug in DM cache metadata's loading of its discard bitset that
could lead to all cache blocks being discarded if the very first
cache block was discarded (thankfully in practice the first cache
block is generally in use; be it FS superblock, partition table, disk
label, etc).
- Add testing-only DM dust target which simulates a device that has
failing sectors and/or read failures.
- Fix a DM init error path reference count hang that caused boot hangs
if user supplied malformed input on kernel commandline.
- Fix a couple issues with DM crypt target's logging being overly
verbose or lacking context.
- Various other small fixes to DM init, DM multipath, DM zoned, and DM
crypt.
* tag 'for-5.2/dm-changes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (42 commits)
dm: fix a couple brace coding style issues
dm crypt: print device name in integrity error message
dm crypt: move detailed message into debug level
dm ioctl: fix hang in early create error condition
dm integrity: whitespace, coding style and dead code cleanup
dm integrity: implement synchronous mode for reboot handling
dm integrity: handle machine reboot in bitmap mode
dm integrity: add a bitmap mode
dm integrity: introduce a function add_new_range_and_wait()
dm integrity: allow large ranges to be described
dm ingerity: pass size to dm_integrity_alloc_page_list()
dm integrity: introduce rw_journal_sectors()
dm integrity: update documentation
dm integrity: don't report unused options
dm integrity: don't check null pointer before kvfree and vfree
dm integrity: correctly calculate the size of metadata area
dm dust: Make dm_dust_init and dm_dust_exit static
dm dust: remove redundant unsigned comparison to less than zero
dm mpath: always free attached_handler_name in parse_path()
dm init: fix max devices/targets checks
...
It turned out that DEBUG_SLAB_LEAK is still broken even after recent
recue efforts that when there is a large number of objects like
kmemleak_object which is normal on a debug kernel,
# grep kmemleak /proc/slabinfo
kmemleak_object 2243606 3436210 ...
reading /proc/slab_allocators could easily loop forever while processing
the kmemleak_object cache and any additional freeing or allocating
objects will trigger a reprocessing. To make a situation worse,
soft-lockups could easily happen in this sitatuion which will call
printk() to allocate more kmemleak objects to guarantee an infinite
loop.
Also, since it seems no one had noticed when it was totally broken
more than 2-year ago - see the commit fcf88917dd ("slab: fix a crash
by reading /proc/slab_allocators"), probably nobody cares about it
anymore due to the decline of the SLAB. Just remove it entirely.
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull core fixes from Ingo Molnar:
"A handful of objtool updates, plus a documentation addition for
__ab_c_size()"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Fix whitelist documentation typo
objtool: Fix function fallthrough detection
objtool: Don't use ignore flag for fake jumps
overflow.h: Add comment documenting __ab_c_size()
Pull ARM SoC-related driver updates from Olof Johansson:
"Various driver updates for platforms and a couple of the small driver
subsystems we merge through our tree:
Among the larger pieces:
- Power management improvements for TI am335x and am437x (RTC
suspend/wake)
- Misc new additions for Amlogic (socinfo updates)
- ZynqMP FPGA manager
- Nvidia improvements for reset/powergate handling
- PMIC wrapper for Mediatek MT8516
- Misc fixes/improvements for ARM SCMI, TEE, NXP i.MX SCU drivers"
* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (57 commits)
soc: aspeed: fix Kconfig
soc: add aspeed folder and misc drivers
spi: zynqmp: Fix build break
soc: imx: Add generic i.MX8 SoC driver
MAINTAINERS: Update email for Qualcomm SoC maintainer
memory: tegra: Fix a typos for "fdcdwr2" mc client
Revert "ARM: tegra: Restore memory arbitration on resume from LP1 on Tegra30+"
memory: tegra: Replace readl-writel with mc_readl-mc_writel
memory: tegra: Fix integer overflow on tick value calculation
memory: tegra: Fix missed registers values latching
ARM: tegra: cpuidle: Handle tick broadcasting within cpuidle core on Tegra20/30
optee: allow to work without static shared memory
soc/tegra: pmc: Move powergate initialisation to probe
soc/tegra: pmc: Remove reset sysfs entries on error
soc/tegra: pmc: Fix reset sources and levels
soc: amlogic: meson-gx-pwrc-vpu: Add support for G12A
soc: amlogic: meson-gx-pwrc-vpu: Fix power on/off register bitmask
fpga manager: Adding FPGA Manager support for Xilinx zynqmp
dt-bindings: fpga: Add bindings for ZynqMP fpga driver
firmware: xilinx: Add fpga API's
...
Pull ARM SoC platform updates from Olof Johansson:
"SoC updates, mostly refactorings and cleanups of old legacy platforms.
Major themes this release:
- Conversion of ixp4xx to a modern platform (drivers, DT, bindings)
- Moving some of the ep93xx headers around to get it closer to
multiplatform enabled.
- Cleanups of Davinci
This also contains a few patches that were queued up as fixes before
5.1 but I didn't get sent in before release"
* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (123 commits)
ARM: debug-ll: add default address for digicolor
ARM: u300: regulator: add MODULE_LICENSE()
ARM: ep93xx: move private headers out of mach/*
ARM: ep93xx: move pinctrl interfaces into include/linux/soc
ARM: ep93xx: keypad: stop using mach/platform.h
ARM: ep93xx: move network platform data to separate header
ARM: stm32: add AMBA support for stm32 family
MAINTAINERS: update arch/arm/mach-davinci
ARM: rockchip: add missing of_node_put in rockchip_smp_prepare_pmu
ARM: dts: Add queue manager and NPE to the IXP4xx DTSI
soc: ixp4xx: qmgr: Add DT probe code
soc: ixp4xx: qmgr: Add DT bindings for IXP4xx qmgr
soc: ixp4xx: npe: Add DT probe code
soc: ixp4xx: Add DT bindings for IXP4xx NPE
soc: ixp4xx: qmgr: Pass resources
soc: ixp4xx: Remove unused functions
soc: ixp4xx: Uninline several functions
soc: ixp4xx: npe: Pass addresses as resources
ARM: ixp4xx: Turn the QMGR into a platform device
ARM: ixp4xx: Turn the NPE into a platform device
...
Pull thermal soc updates from Eduardo Valentin:
- thermal core has a new devm_* API for registering cooling devices. I
took the entire series, that is why you see changes on drivers/hwmon
in this pull (Guenter Roeck)
- rockchip thermal driver gains support to PX30 SoC (Elaine Zhang)
- the generic-adc thermal driver now considers the lookup table DT
property as optional (Jean-Francois Dagenais)
- Refactoring of tsens thermal driver (Amit Kucheria)
- Cleanups on cpu cooling driver (Daniel Lezcano)
- broadcom thermal driver dropped support to ACPI (Srinath Mannam)
- tegra thermal driver gains support to OC hw throttle and GPU throtle
(Wei Ni)
- Fixes in several thermal drivers.
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal: (59 commits)
hwmon: (pwm-fan) Use devm_thermal_of_cooling_device_register
hwmon: (npcm750-pwm-fan) Use devm_thermal_of_cooling_device_register
hwmon: (mlxreg-fan) Use devm_thermal_of_cooling_device_register
hwmon: (gpio-fan) Use devm_thermal_of_cooling_device_register
hwmon: (aspeed-pwm-tacho) Use devm_thermal_of_cooling_device_register
thermal: rcar_gen3_thermal: Fix to show correct trip points number
thermal: rcar_thermal: update calculation formula for R-Car Gen3 SoCs
thermal: cpu_cooling: Actually trace CPU load in thermal_power_cpu_get_power
thermal: rockchip: Support the PX30 SoC in thermal driver
dt-bindings: rockchip-thermal: Support the PX30 SoC compatible
thermal: rockchip: fix up the tsadc pinctrl setting error
thermal: broadcom: Remove ACPI support
thermal: Fix build error of missing devm_ioremap_resource on UM
thermal/drivers/cpu_cooling: Remove pointless field
thermal/drivers/cpu_cooling: Add Software Package Data Exchange (SPDX)
thermal/drivers/cpu_cooling: Fixup the header and copyright
thermal/drivers/cpu_cooling: Remove pointless test in power2state()
thermal: rcar_gen3_thermal: disable interrupt in .remove
thermal: rcar_gen3_thermal: fix interrupt type
thermal: Introduce devm_thermal_of_cooling_device_register
...
Merge in a few pending fixes from pre-5.1 that didn't get sent in:
MAINTAINERS: update arch/arm/mach-davinci
ARM: dts: ls1021: Fix SGMII PCS link remaining down after PHY disconnect
ARM: dts: imx6q-logicpd: Reduce inrush current on USBH1
ARM: dts: imx6q-logicpd: Reduce inrush current on start
ARM: dts: imx: Fix the AR803X phy-mode
ARM: dts: sun8i: a33: Reintroduce default pinctrl muxing
arm64: dts: allwinner: a64: Rename hpvcc-supply to cpvdd-supply
ARM: sunxi: fix a leaked reference by adding missing of_node_put
ARM: sunxi: fix a leaked reference by adding missing of_node_put
Signed-off-by: Olof Johansson <olof@lixom.net>
Pull power supply and reset updates from Sebastian Reichel:
"Core:
- Add over-current health state
- Add standard, adaptive and custom charge types
- Add new properties for start/end charge threshold
New Drivers / Hardware:
- UCS1002 Programmable USB Port Power Controller
- Ingenic JZ47xx Battery Fuel Gauge
- AXP20x USB Power: Add AXP813 support
- AT91 poweroff: Add SAM9X60 support
- OLPC battery: Add XO-1.5 and XO-1.75 support
Misc Changes:
- syscon-reboot: support mask property
- AXP288 fuel gauge: Blacklist ACEPC T8/T11. Looks like some vendor
thought it's a good idea to build a desktop system with a fuel
gauge, that slowly "discharges"...
- cpcap-battery: Fix calculation errors
- misc fixes"
* tag 'for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply: (54 commits)
power: supply: olpc_battery: force the le/be casts
power: supply: ucs1002: Fix build error without CONFIG_REGULATOR
power: supply: ucs1002: Fix wrong return value checking
power: supply: Add driver for Microchip UCS1002
dt-bindings: power: supply: Add bindings for Microchip UCS1002
power: supply: core: Add POWER_SUPPLY_HEALTH_OVERCURRENT constant
power: supply: core: fix clang -Wunsequenced
power: supply: core: Add missing documentation for CHARGE_CONTROL_* properties
power: supply: core: Add CHARGE_CONTROL_{START_THRESHOLD,END_THRESHOLD} properties
power: supply: core: Add Standard, Adaptive, and Custom charge types
power: supply: axp288_fuel_gauge: Add ACEPC T8 and T11 mini PCs to the blacklist
power: supply: bq27xxx_battery: Notify also about status changes
power: supply: olpc_battery: Have the framework register sysfs files for us
power: supply: olpc_battery: Add OLPC XO 1.75 support
power: supply: olpc_battery: Avoid using platform_info
power: supply: olpc_battery: Use devm_power_supply_register()
power: supply: olpc_battery: Move priv data to a struct
power: supply: olpc_battery: Use DT to get battery version
x86/platform/olpc: Use a correct version when making up a battery node
x86/platform/olpc: Trivial code move in DT fixup
...
Pull nfsd updates from Bruce Fields:
"This consists mostly of nfsd container work:
Scott Mayhew revived an old api that communicates with a userspace
daemon to manage some on-disk state that's used to track clients
across server reboots. We've been using a usermode_helper upcall for
that, but it's tough to run those with the right namespaces, so a
daemon is much friendlier to container use cases.
Trond fixed nfsd's handling of user credentials in user namespaces. He
also contributed patches that allow containers to support different
sets of NFS protocol versions.
The only remaining container bug I'm aware of is that the NFS reply
cache is shared between all containers. If anyone's aware of other
gaps in our container support, let me know.
The rest of this is miscellaneous bugfixes"
* tag 'nfsd-5.2' of git://linux-nfs.org/~bfields/linux: (23 commits)
nfsd: update callback done processing
locks: move checks from locks_free_lock() to locks_release_private()
nfsd: fh_drop_write in nfsd_unlink
nfsd: allow fh_want_write to be called twice
nfsd: knfsd must use the container user namespace
SUNRPC: rsi_parse() should use the current user namespace
SUNRPC: Fix the server AUTH_UNIX userspace mappings
lockd: Pass the user cred from knfsd when starting the lockd server
SUNRPC: Temporary sockets should inherit the cred from their parent
SUNRPC: Cache the process user cred in the RPC server listener
nfsd: Allow containers to set supported nfs versions
nfsd: Add custom rpcbind callbacks for knfsd
SUNRPC: Allow further customisation of RPC program registration
SUNRPC: Clean up generic dispatcher code
SUNRPC: Add a callback to initialise server requests
SUNRPC/nfs: Fix return value for nfs4_callback_compound()
nfsd: handle legacy client tracking records sent by nfsdcld
nfsd: re-order client tracking method selection
nfsd: keep a tally of RECLAIM_COMPLETE operations when using nfsdcld
nfsd: un-deprecate nfsdcld
...
Pull tracing updates from Steven Rostedt:
"The major changes in this tracing update includes:
- Removal of non-DYNAMIC_FTRACE from 32bit x86
- Removal of mcount support from x86
- Emulating a call from int3 on x86_64, fixes live kernel patching
- Consolidated Tracing Error logs file
Minor updates:
- Removal of klp_check_compiler_support()
- kdb ftrace dumping output changes
- Accessing and creating ftrace instances from inside the kernel
- Clean up of #define if macro
- Introduction of TRACE_EVENT_NOP() to disable trace events based on
config options
And other minor fixes and clean ups"
* tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
x86: Hide the int3_emulate_call/jmp functions from UML
livepatch: Remove klp_check_compiler_support()
ftrace/x86: Remove mcount support
ftrace/x86_32: Remove support for non DYNAMIC_FTRACE
tracing: Simplify "if" macro code
tracing: Fix documentation about disabling options using trace_options
tracing: Replace kzalloc with kcalloc
tracing: Fix partial reading of trace event's id file
tracing: Allow RCU to run between postponed startup tests
tracing: Fix white space issues in parse_pred() function
tracing: Eliminate const char[] auto variables
ring-buffer: Fix mispelling of Calculate
tracing: probeevent: Fix to make the type of $comm string
tracing: probeevent: Do not accumulate on ret variable
tracing: uprobes: Re-enable $comm support for uprobe events
ftrace/x86_64: Emulate call function while updating in breakpoint handler
x86_64: Allow breakpoints to emulate call instructions
x86_64: Add gap to int3 to allow for call emulation
tracing: kdb: Allow ftdump to skip all but the last few entries
tracing: Add trace_total_entries() / trace_total_entries_cpu()
...
PPC KVM update for 5.2
* Support for guests to access the new POWER9 XIVE interrupt controller
hardware directly, reducing interrupt latency and overhead for guests.
* In-kernel implementation of the H_PAGE_INIT hypercall.
* Reduce memory usage of sparsely-populated IOMMU tables.
* Several bug fixes.
Second PPC KVM update for 5.2
* Fix a bug, fix a spelling mistake, remove some useless code.
Add wait_var_event_interruptible() to allow interruptible waits for events.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Allow used DNS resolver keys to be invalidated after use if the caller is
doing its own caching of the results. This reduces the amount of resources
required.
Fix AFS to invalidate DNS results to kill off permanent failure records
that get lodged in the resolver keyring and prevent future lookups from
happening.
Fixes: 0a5143f2f8 ("afs: Implement VL server rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
Pull more power management updates from Rafael Wysocki:
"These fix a recent regression causing kernels built with CONFIG_PM
unset to crash on systems that support the Performance and Energy Bias
Hint (EPB), clean up the cpufreq core and some users of transition
notifiers and introduce a new power domain flag into the generic power
domains framework (genpd).
Specifics:
- Fix recent regression causing kernels built with CONFIG_PM unset to
crash on systems that support the Performance and Energy Bias Hint
(EPB) by avoiding to compile the EPB-related code depending on
CONFIG_PM when it is unset (Rafael Wysocki).
- Clean up the transition notifier invocation code in the cpufreq
core and change some users of cpufreq transition notifiers
accordingly (Viresh Kumar).
- Change MAINTAINERS to cover the schedutil governor as part of
cpufreq (Viresh Kumar).
- Simplify cpufreq_init_policy() to avoid redundant computations (Yue
Hu).
- Add explanatory comment to the cpufreq core (Rafael Wysocki).
- Introduce a new flag, GENPD_FLAG_RPM_ALWAYS_ON, to the generic
power domains (genpd) framework along with the first user of it
(Leonard Crestez)"
* tag 'pm-5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
soc: imx: gpc: Use GENPD_FLAG_RPM_ALWAYS_ON for ERR009619
PM / Domains: Add GENPD_FLAG_RPM_ALWAYS_ON flag
cpufreq: Update MAINTAINERS to include schedutil governor
cpufreq: Don't find governor for setpolicy drivers in cpufreq_init_policy()
cpufreq: Explain the kobject_put() in cpufreq_policy_alloc()
cpufreq: Call transition notifier only once for each policy
x86: intel_epb: Take CONFIG_PM into account
* pm-cpufreq:
cpufreq: Update MAINTAINERS to include schedutil governor
cpufreq: Don't find governor for setpolicy drivers in cpufreq_init_policy()
cpufreq: Explain the kobject_put() in cpufreq_policy_alloc()
cpufreq: Call transition notifier only once for each policy
* pm-domains:
soc: imx: gpc: Use GENPD_FLAG_RPM_ALWAYS_ON for ERR009619
PM / Domains: Add GENPD_FLAG_RPM_ALWAYS_ON flag
Pull more rdma updates from Jason Gunthorpe:
"This is being sent to get a fix for the gcc 9.1 build warnings, and
I've also pulled in some bug fix patches that were posted in the last
two weeks.
- Avoid the gcc 9.1 warning about overflowing a union member
- Fix the wrong callback type for a single response netlink to doit
- Bug fixes from more usage of the mlx5 devx interface"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
net/mlx5: Set completion EQs as shared resources
IB/mlx5: Verify DEVX general object type correctly
RDMA/core: Change system parameters callback from dumpit to doit
RDMA: Directly cast the sockaddr union to sockaddr
Merge more updates from Andrew Morton:
- a couple of hotfixes
- almost all of the rest of MM
- lib/ updates
- binfmt_elf updates
- autofs updates
- quite a lot of misc fixes and updates
- reiserfs, fatfs
- signals
- exec
- cpumask
- rapidio
- sysctl
- pids
- eventfd
- gcov
- panic
- pps
- gdb script updates
- ipc updates
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (126 commits)
mm: memcontrol: fix NUMA round-robin reclaim at intermediate level
mm: memcontrol: fix recursive statistics correctness & scalabilty
mm: memcontrol: move stat/event counting functions out-of-line
mm: memcontrol: make cgroup stats and events query API explicitly local
drivers/virt/fsl_hypervisor.c: prevent integer overflow in ioctl
drivers/virt/fsl_hypervisor.c: dereferencing error pointers in ioctl
mm, memcg: rename ambiguously named memory.stat counters and functions
arch: remove <asm/sizes.h> and <asm-generic/sizes.h>
treewide: replace #include <asm/sizes.h> with #include <linux/sizes.h>
fs/block_dev.c: Remove duplicate header
fs/cachefiles/namei.c: remove duplicate header
include/linux/sched/signal.h: replace `tsk' with `task'
fs/coda/psdev.c: remove duplicate header
ipc: do cyclic id allocation for the ipc object.
ipc: conserve sequence numbers in ipcmni_extend mode
ipc: allow boot time extension of IPCMNI from 32k to 16M
ipc/mqueue: optimize msg_get()
ipc/mqueue: remove redundant wq task assignment
ipc: prevent lockup on alloc_msg and free_msg
scripts/gdb: print cached rate in lx-clk-summary
...
Right now, when somebody needs to know the recursive memory statistics
and events of a cgroup subtree, they need to walk the entire subtree and
sum up the counters manually.
There are two issues with this:
1. When a cgroup gets deleted, its stats are lost. The state counters
should all be 0 at that point, of course, but the events are not.
When this happens, the event counters, which are supposed to be
monotonic, can go backwards in the parent cgroups.
2. During regular operation, we always have a certain number of lazily
freed cgroups sitting around that have been deleted, have no tasks,
but have a few cache pages remaining. These groups' statistics do not
change until we eventually hit memory pressure, but somebody
watching, say, memory.stat on an ancestor has to iterate those every
time.
This patch addresses both issues by introducing recursive counters at
each level that are propagated from the write side when stats change.
Upward propagation happens when the per-cpu caches spill over into the
local atomic counter. This is the same thing we do during charge and
uncharge, except that the latter uses atomic RMWs, which are more
expensive; stat changes happen at around the same rate. In a sparse
file test (page faults and reclaim at maximum CPU speed) with 5 cgroup
nesting levels, perf shows __mod_memcg_page state at ~1%.
Link: http://lkml.kernel.org/r/20190412151507.2769-4-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: memcontrol: memory.stat cost & correctness".
The cgroup memory.stat file holds recursive statistics for the entire
subtree. The current implementation does this tree walk on-demand
whenever the file is read. This is giving us problems in production.
1. The cost of aggregating the statistics on-demand is high. A lot of
system service cgroups are mostly idle and their stats don't change
between reads, yet we always have to check them. There are also always
some lazily-dying cgroups sitting around that are pinned by a handful
of remaining page cache; the same applies to them.
In an application that periodically monitors memory.stat in our
fleet, we have seen the aggregation consume up to 5% CPU time.
2. When cgroups die and disappear from the cgroup tree, so do their
accumulated vm events. The result is that the event counters at
higher-level cgroups can go backwards and confuse some of our
automation, let alone people looking at the graphs over time.
To address both issues, this patch series changes the stat
implementation to spill counts upwards when the counters change.
The upward spilling is batched using the existing per-cpu cache. In a
sparse file stress test with 5 level cgroup nesting, the additional cost
of the flushing was negligible (a little under 1% of CPU at 100% CPU
utilization, compared to the 5% of reading memory.stat during regular
operation).
This patch (of 4):
memcg_page_state(), lruvec_page_state(), memcg_sum_events() are
currently returning the state of the local memcg or lruvec, not the
recursive state.
In practice there is a demand for both versions, although the callers
that want the recursive counts currently sum them up by hand.
Per default, cgroups are considered recursive entities and generally we
expect more users of the recursive counters, with the local counts being
special cases. To reflect that in the name, add a _local suffix to the
current implementations.
The following patch will re-incarnate these functions with recursive
semantics, but with an O(1) implementation.
[hannes@cmpxchg.org: fix bisection hole]
Link: http://lkml.kernel.org/r/20190417160347.GC23013@cmpxchg.org
Link: http://lkml.kernel.org/r/20190412151507.2769-2-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I spent literally an hour trying to work out why an earlier version of
my memory.events aggregation code doesn't work properly, only to find
out I was calling memcg->events instead of memcg->memory_events, which
is fairly confusing.
This naming seems in need of reworking, so make it harder to do the
wrong thing by using vmevents instead of events, which makes it more
clear that these are vm counters rather than memcg-specific counters.
There are also a few other inconsistent names in both the percpu and
aggregated structs, so these are all cleaned up to be more coherent and
easy to understand.
This commit contains code cleanup only: there are no logic changes.
[akpm@linux-foundation.org: fix it for preceding changes]
Link: http://lkml.kernel.org/r/20190208224319.GA23801@chrisdown.name
Signed-off-by: Chris Down <chris@chrisdown.name>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rewrite, based on the patch from Waiman Long:
The mixing in of a sequence number into the IPC IDs is probably to avoid
ID reuse in userspace as much as possible. With ipcmni_extend mode, the
number of usable sequence numbers is greatly reduced leading to higher
chance of ID reuse.
To address this issue, we need to conserve the sequence number space as
much as possible. Right now, the sequence number is incremented for
every new ID created. In reality, we only need to increment the
sequence number when new allocated ID is not greater than the last one
allocated. It is in such case that the new ID may collide with an
existing one. This is being done irrespective of the ipcmni mode.
In order to avoid any races, the index is first allocated and then the
pointer is replaced.
Changes compared to the initial patch:
- Handle failures from idr_alloc().
- Avoid that concurrent operations can see the wrong sequence number.
(This is achieved by using idr_replace()).
- IPCMNI_SEQ_SHIFT is not a constant, thus renamed to
ipcmni_seq_shift().
- IPCMNI_SEQ_MAX is not a constant, thus renamed to ipcmni_seq_max().
Link: http://lkml.kernel.org/r/20190329204930.21620-2-longman@redhat.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When kernel panic happens, it will first print the panic call stack,
then the ending msg like:
[ 35.743249] ---[ end Kernel panic - not syncing: Fatal exception
[ 35.749975] ------------[ cut here ]------------
The above message are very useful for debugging.
But if system is configured to not reboot on panic, say the
"panic_timeout" parameter equals 0, it will likely print out many noisy
message like WARN() call stack for each and every CPU except the panic
one, messages like below:
WARNING: CPU: 1 PID: 280 at kernel/sched/core.c:1198 set_task_cpu+0x183/0x190
Call Trace:
<IRQ>
try_to_wake_up
default_wake_function
autoremove_wake_function
__wake_up_common
__wake_up_common_lock
__wake_up
wake_up_klogd_work_func
irq_work_run_list
irq_work_tick
update_process_times
tick_sched_timer
__hrtimer_run_queues
hrtimer_interrupt
smp_apic_timer_interrupt
apic_timer_interrupt
For people working in console mode, the screen will first show the panic
call stack, but immediately overridden by these noisy extra messages,
which makes debugging much more difficult, as the original context gets
lost on screen.
Also these noisy messages will confuse some users, as I have seen many bug
reporters posted the noisy message into bugzilla, instead of the real
panic call stack and context.
Adding a flag "suppress_printk" which gets set in panic() to avoid those
noisy messages, without changing current kernel behavior that both panic
blinking and sysrq magic key can work as is, suggested by Petr Mladek.
To verify this, make sure kernel is not configured to reboot on panic and
in console
# echo c > /proc/sysrq-trigger
to see if console only prints out the panic call stack.
Link: http://lkml.kernel.org/r/1551430186-24169-1-git-send-email-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Suggested-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
struct linux_binprm::buf is the first field and it is exactly 128 bytes
in size. It means that on x86_64 all accesses to other fields will go
though [r64 + disp32] addressing mode which is 3 bytes bloatier than
[r64 + disp8] addressing mode. Given that accesses to other fields
outnumber accesses to ->buf, move it down.
Space savings (x86_64 defconfig):
more on distro configs because LSMs actively dereference "bprm"
but do not care about first 128 bytes of the executable itself.
add/remove: 0/0 grow/shrink: 0/24 up/down: 0/-492 (-492)
Function old new delta
selinux_bprm_committing_creds 552 549 -3
finalize_exec 94 91 -3
__audit_log_bprm_fcaps 283 280 -3
__audit_bprm 39 36 -3
perf_trace_sched_process_exec 347 341 -6
install_exec_creds 105 99 -6
cap_bprm_set_creds.cold 60 54 -6
would_dump 137 128 -9
load_script 637 628 -9
bprm_change_interp 61 52 -9
trace_event_raw_event_sched_process_exec 260 250 -10
search_binary_handler 255 240 -15
remove_arg_zero 295 277 -18
free_bprm 119 101 -18
prepare_binprm 379 360 -19
setup_new_exec 336 315 -21
flush_old_exec 1638 1617 -21
copy_strings.isra 746 724 -22
setup_arg_pages 559 530 -29
load_misc_binary 1151 1118 -33
selinux_bprm_set_creds 792 753 -39
load_elf_binary 11111 11072 -39
cap_bprm_set_creds 1496 1454 -42
__do_execve_file.isra 2395 2286 -109
Link: http://lkml.kernel.org/r/20190421165025.GA26843@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ror32 implementation (word >> shift) | (word << (32 - shift) has
undefined behaviour if shift is outside the [1, 31] range. Similarly
for the 64 bit variants. Most callers pass a compile-time constant
(naturally in that range), but there's an UBSAN report that these may
actually be called with a shift count of 0.
Instead of special-casing that, we can make them DTRT for all values of
shift while also avoiding UB. For some reason, this was already partly
done for rol32 (which was well-defined for [0, 31]). gcc 8 recognizes
these patterns as rotates, so for example
__u32 rol32(__u32 word, unsigned int shift)
{
return (word << (shift & 31)) | (word >> ((-shift) & 31));
}
compiles to
0000000000000020 <rol32>:
20: 89 f8 mov %edi,%eax
22: 89 f1 mov %esi,%ecx
24: d3 c0 rol %cl,%eax
26: c3 retq
Older compilers unfortunately do not do as well, but this only affects
the small minority of users that don't pass constants.
Due to integer promotions, ro[lr]8 were already well-defined for shifts
in [0, 8], and ro[lr]16 were mostly well-defined for shifts in [0, 16]
(only mostly - u16 gets promoted to _signed_ int, so if bit 15 is set,
word << 16 is undefined). For consistency, update those as well.
Link: http://lkml.kernel.org/r/20190410211906.2190-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reported-by: Ido Schimmel <idosch@mellanox.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Cc: Vadim Pasternak <vadimp@mellanox.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rather than a fixed-size array of pending sorted runs, use the ->prev
links to keep track of things. This reduces stack usage, eliminates
some ugly overflow handling, and reduces the code size.
Also:
* merge() no longer needs to handle NULL inputs, so simplify.
* The same applies to merge_and_restore_back_links(), which is renamed
to the less ponderous merge_final(). (It's a static helper function,
so we don't need a super-descriptive name; comments will do.)
* Document the actual return value requirements on the (*cmp)()
function; some callers are already using this feature.
x86-64 code size 1086 -> 739 bytes (-347)
(Yes, I see checkpatch complaining about no space after comma in
"__attribute__((nonnull(2,3,4,5)))". Checkpatch is wrong.)
Feedback from Rasmus Villemoes, Andy Shevchenko and Geert Uytterhoeven.
[akpm@linux-foundation.org: remove __pure usage due to mysterious warning]
Link: http://lkml.kernel.org/r/f63c410e0ff76009c9b58e01027e751ff7fdb749.1552704200.git.lkml@sdf.org
Signed-off-by: George Spelvin <lkml@sdf.org>
Acked-by: Andrey Abramov <st5pub@yandex.ru>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Daniel Wagner <daniel.wagner@siemens.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Don Mullis <don.mullis@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The "WITH Linux-syscall-note" should be added to headers exported to the
user-space.
Some kernel-space headers have "WITH Linux-syscall-note", which seems a
mistake.
[1] arch/x86/include/asm/hyperv-tlfs.h
Commit 5a48580322 ("x86/hyper-v: move hyperv.h out of uapi") moved
this file out of uapi, but missed to update the SPDX License tag.
[2] include/asm-generic/shmparam.h
Commit 76ce2a80a2 ("Rename include/{uapi => }/asm-generic/shmparam.h
really") moved this file out of uapi, but missed to update the SPDX
License tag.
[3] include/linux/qcom-geni-se.h
Commit eddac5af06 ("soc: qcom: Add GENI based QUP Wrapper driver")
added this file, but I do not see a good reason why its license tag must
include "WITH Linux-syscall-note".
Link: http://lkml.kernel.org/r/1554196104-3522-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The select() implementation is carefully tuned to put a sensible amount
of data on the stack for holding a copy of the user space fd_set, but
not too large to risk overflowing the kernel stack.
When building a 32-bit kernel with clang, we need a little more space
than with gcc, which often triggers a warning:
fs/select.c:619:5: error: stack frame size of 1048 bytes in function 'core_sys_select' [-Werror,-Wframe-larger-than=]
int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
I experimentally found that for 32-bit ARM, reducing the maximum stack
usage by 64 bytes keeps us reliably under the warning limit again.
Link: http://lkml.kernel.org/r/20190307090146.1874906-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: Randomize free memory", v10.
This patch (of 3):
Randomization of the page allocator improves the average utilization of
a direct-mapped memory-side-cache. Memory side caching is a platform
capability that Linux has been previously exposed to in HPC
(high-performance computing) environments on specialty platforms. In
that instance it was a smaller pool of high-bandwidth-memory relative to
higher-capacity / lower-bandwidth DRAM. Now, this capability is going
to be found on general purpose server platforms where DRAM is a cache in
front of higher latency persistent memory [1].
Robert offered an explanation of the state of the art of Linux
interactions with memory-side-caches [2], and I copy it here:
It's been a problem in the HPC space:
http://www.nersc.gov/research-and-development/knl-cache-mode-performance-coe/
A kernel module called zonesort is available to try to help:
https://software.intel.com/en-us/articles/xeon-phi-software
and this abandoned patch series proposed that for the kernel:
https://lkml.kernel.org/r/20170823100205.17311-1-lukasz.daniluk@intel.com
Dan's patch series doesn't attempt to ensure buffers won't conflict, but
also reduces the chance that the buffers will. This will make performance
more consistent, albeit slower than "optimal" (which is near impossible
to attain in a general-purpose kernel). That's better than forcing
users to deploy remedies like:
"To eliminate this gradual degradation, we have added a Stream
measurement to the Node Health Check that follows each job;
nodes are rebooted whenever their measured memory bandwidth
falls below 300 GB/s."
A replacement for zonesort was merged upstream in commit cc9aec03e5
("x86/numa_emulation: Introduce uniform split capability"). With this
numa_emulation capability, memory can be split into cache sized
("near-memory" sized) numa nodes. A bind operation to such a node, and
disabling workloads on other nodes, enables full cache performance.
However, once the workload exceeds the cache size then cache conflicts
are unavoidable. While HPC environments might be able to tolerate
time-scheduling of cache sized workloads, for general purpose server
platforms, the oversubscribed cache case will be the common case.
The worst case scenario is that a server system owner benchmarks a
workload at boot with an un-contended cache only to see that performance
degrade over time, even below the average cache performance due to
excessive conflicts. Randomization clips the peaks and fills in the
valleys of cache utilization to yield steady average performance.
Here are some performance impact details of the patches:
1/ An Intel internal synthetic memory bandwidth measurement tool, saw a
3X speedup in a contrived case that tries to force cache conflicts.
The contrived cased used the numa_emulation capability to force an
instance of the benchmark to be run in two of the near-memory sized
numa nodes. If both instances were placed on the same emulated they
would fit and cause zero conflicts. While on separate emulated nodes
without randomization they underutilized the cache and conflicted
unnecessarily due to the in-order allocation per node.
2/ A well known Java server application benchmark was run with a heap
size that exceeded cache size by 3X. The cache conflict rate was 8%
for the first run and degraded to 21% after page allocator aging. With
randomization enabled the rate levelled out at 11%.
3/ A MongoDB workload did not observe measurable difference in
cache-conflict rates, but the overall throughput dropped by 7% with
randomization in one case.
4/ Mel Gorman ran his suite of performance workloads with randomization
enabled on platforms without a memory-side-cache and saw a mix of some
improvements and some losses [3].
While there is potentially significant improvement for applications that
depend on low latency access across a wide working-set, the performance
may be negligible to negative for other workloads. For this reason the
shuffle capability defaults to off unless a direct-mapped
memory-side-cache is detected. Even then, the page_alloc.shuffle=0
parameter can be specified to disable the randomization on those systems.
Outside of memory-side-cache utilization concerns there is potentially
security benefit from randomization. Some data exfiltration and
return-oriented-programming attacks rely on the ability to infer the
location of sensitive data objects. The kernel page allocator, especially
early in system boot, has predictable first-in-first out behavior for
physical pages. Pages are freed in physical address order when first
onlined.
Quoting Kees:
"While we already have a base-address randomization
(CONFIG_RANDOMIZE_MEMORY), attacks against the same hardware and
memory layouts would certainly be using the predictability of
allocation ordering (i.e. for attacks where the base address isn't
important: only the relative positions between allocated memory).
This is common in lots of heap-style attacks. They try to gain
control over ordering by spraying allocations, etc.
I'd really like to see this because it gives us something similar
to CONFIG_SLAB_FREELIST_RANDOM but for the page allocator."
While SLAB_FREELIST_RANDOM reduces the predictability of some local slab
caches it leaves vast bulk of memory to be predictably in order allocated.
However, it should be noted, the concrete security benefits are hard to
quantify, and no known CVE is mitigated by this randomization.
Introduce shuffle_free_memory(), and its helper shuffle_zone(), to perform
a Fisher-Yates shuffle of the page allocator 'free_area' lists when they
are initially populated with free memory at boot and at hotplug time. Do
this based on either the presence of a page_alloc.shuffle=Y command line
parameter, or autodetection of a memory-side-cache (to be added in a
follow-on patch).
The shuffling is done in terms of CONFIG_SHUFFLE_PAGE_ORDER sized free
pages where the default CONFIG_SHUFFLE_PAGE_ORDER is MAX_ORDER-1 i.e. 10,
4MB this trades off randomization granularity for time spent shuffling.
MAX_ORDER-1 was chosen to be minimally invasive to the page allocator
while still showing memory-side cache behavior improvements, and the
expectation that the security implications of finer granularity
randomization is mitigated by CONFIG_SLAB_FREELIST_RANDOM. The
performance impact of the shuffling appears to be in the noise compared to
other memory initialization work.
This initial randomization can be undone over time so a follow-on patch is
introduced to inject entropy on page free decisions. It is reasonable to
ask if the page free entropy is sufficient, but it is not enough due to
the in-order initial freeing of pages. At the start of that process
putting page1 in front or behind page0 still keeps them close together,
page2 is still near page1 and has a high chance of being adjacent. As
more pages are added ordering diversity improves, but there is still high
page locality for the low address pages and this leads to no significant
impact to the cache conflict rate.
[1]: https://itpeernetwork.intel.com/intel-optane-dc-persistent-memory-operating-modes/
[2]: https://lkml.kernel.org/r/AT5PR8401MB1169D656C8B5E121752FC0F8AB120@AT5PR8401MB1169.NAMPRD84.PROD.OUTLOOK.COM
[3]: https://lkml.org/lkml/2018/10/12/309
[dan.j.williams@intel.com: fix shuffle enable]
Link: http://lkml.kernel.org/r/154943713038.3858443.4125180191382062871.stgit@dwillia2-desk3.amr.corp.intel.com
[cai@lca.pw: fix SHUFFLE_PAGE_ALLOCATOR help texts]
Link: http://lkml.kernel.org/r/20190425201300.75650-1-cai@lca.pw
Link: http://lkml.kernel.org/r/154899811738.3165233.12325692939590944259.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Robert Elliott <elliott@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Psi monitor aims to provide a low-latency short-term pressure detection
mechanism configurable by users. It allows users to monitor psi metrics
growth and trigger events whenever a metric raises above user-defined
threshold within user-defined time window.
Time window and threshold are both expressed in usecs. Multiple psi
resources with different thresholds and window sizes can be monitored
concurrently.
Psi monitors activate when system enters stall state for the monitored
psi metric and deactivate upon exit from the stall state. While system
is in the stall state psi signal growth is monitored at a rate of 10
times per tracking window. Min window size is 500ms, therefore the min
monitoring interval is 50ms. Max window size is 10s with monitoring
interval of 1s.
When activated psi monitor stays active for at least the duration of one
tracking window to avoid repeated activations/deactivations when psi
signal is bouncing.
Notifications to the users are rate-limited to one per tracking window.
Link: http://lkml.kernel.org/r/20190319235619.260832-8-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
