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9799 commits

Author SHA1 Message Date
David Keitel
f2b1fed1bd Merge remote-tracking branch 'lsk-44/linux-linaro-lsk-v4.4' into 44rc2
* lsk-44/linux-linaro-lsk-v4.4:
  Linux 4.4.3
  modules: fix modparam async_probe request
  module: wrapper for symbol name.
  itimers: Handle relative timers with CONFIG_TIME_LOW_RES proper
  posix-timers: Handle relative timers with CONFIG_TIME_LOW_RES proper
  timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper
  prctl: take mmap sem for writing to protect against others
  xfs: log mount failures don't wait for buffers to be released
  Revert "xfs: clear PF_NOFREEZE for xfsaild kthread"
  xfs: inode recovery readahead can race with inode buffer creation
  libxfs: pack the agfl header structure so XFS_AGFL_SIZE is correct
  ovl: setattr: check permissions before copy-up
  ovl: root: copy attr
  ovl: check dentry positiveness in ovl_cleanup_whiteouts()
  ovl: use a minimal buffer in ovl_copy_xattr
  ovl: allow zero size xattr
  futex: Drop refcount if requeue_pi() acquired the rtmutex
  devm_memremap_release(): fix memremap'd addr handling
  ipc/shm: handle removed segments gracefully in shm_mmap()
  intel_scu_ipcutil: underflow in scu_reg_access()
  mm,thp: khugepaged: call pte flush at the time of collapse
  dump_stack: avoid potential deadlocks
  radix-tree: fix oops after radix_tree_iter_retry
  drivers/hwspinlock: fix race between radix tree insertion and lookup
  radix-tree: fix race in gang lookup
  MAINTAINERS: return arch/sh to maintained state, with new maintainers
  memcg: only free spare array when readers are done
  numa: fix /proc/<pid>/numa_maps for hugetlbfs on s390
  fs/hugetlbfs/inode.c: fix bugs in hugetlb_vmtruncate_list()
  scripts/bloat-o-meter: fix python3 syntax error
  dma-debug: switch check from _text to _stext
  m32r: fix m32104ut_defconfig build fail
  xhci: Fix list corruption in urb dequeue at host removal
  Revert "xhci: don't finish a TD if we get a short-transfer event mid TD"
  iommu/vt-d: Clear PPR bit to ensure we get more page request interrupts
  iommu/vt-d: Fix 64-bit accesses to 32-bit DMAR_GSTS_REG
  iommu/vt-d: Fix mm refcounting to hold mm_count not mm_users
  iommu/amd: Correct the wrong setting of alias DTE in do_attach
  iommu/vt-d: Don't skip PCI devices when disabling IOTLB
  Input: vmmouse - fix absolute device registration
  string_helpers: fix precision loss for some inputs
  Input: i8042 - add Fujitsu Lifebook U745 to the nomux list
  Input: elantech - mark protocols v2 and v3 as semi-mt
  mm: fix regression in remap_file_pages() emulation
  mm: replace vma_lock_anon_vma with anon_vma_lock_read/write
  mm: fix mlock accouting
  libnvdimm: fix namespace object confusion in is_uuid_busy()
  mm: soft-offline: check return value in second __get_any_page() call
  perf kvm record/report: 'unprocessable sample' error while recording/reporting guest data
  KVM: PPC: Fix ONE_REG AltiVec support
  KVM: PPC: Fix emulation of H_SET_DABR/X on POWER8
  KVM: arm/arm64: Fix reference to uninitialised VGIC
  arm64: dma-mapping: fix handling of devices registered before arch_initcall
  ARM: OMAP2+: Fix ppa_zero_params and ppa_por_params for rodata
  ARM: OMAP2+: Fix save_secure_ram_context for rodata
  ARM: OMAP2+: Fix l2dis_3630 for rodata
  ARM: OMAP2+: Fix l2_inv_api_params for rodata
  ARM: OMAP2+: Fix wait_dll_lock_timed for rodata
  ARM: dts: at91: sama5d4ek: add phy address and IRQ for macb0
  ARM: dts: at91: sama5d4 xplained: fix phy0 IRQ type
  ARM: dts: at91: sama5d4: fix instance id of DBGU
  ARM: dts: at91: sama5d4 xplained: properly mux phy interrupt
  ARM: dts: omap5-board-common: enable rtc and charging of backup battery
  ARM: dts: Fix omap5 PMIC control lines for RTC writes
  ARM: dts: Fix wl12xx missing clocks that cause hangs
  ARM: nomadik: fix up SD/MMC DT settings
  ARM: 8517/1: ICST: avoid arithmetic overflow in icst_hz()
  ARM: 8519/1: ICST: try other dividends than 1
  arm64: mm: avoid calling apply_to_page_range on empty range
  ARM: mvebu: remove duplicated regulator definition in Armada 388 GP
  powerpc/ioda: Set "read" permission when "write" is set
  powerpc/powernv: Fix stale PE primary bus
  powerpc/eeh: Fix stale cached primary bus
  powerpc/eeh: Fix PE location code
  SUNRPC: Fixup socket wait for memory
  udf: Check output buffer length when converting name to CS0
  udf: Prevent buffer overrun with multi-byte characters
  udf: limit the maximum number of indirect extents in a row
  pNFS/flexfiles: Fix an XDR encoding bug in layoutreturn
  nfs: Fix race in __update_open_stateid()
  pNFS/flexfiles: Fix an Oopsable typo in ff_mirror_match_fh()
  NFS: Fix attribute cache revalidation
  cifs: fix erroneous return value
  cifs_dbg() outputs an uninitialized buffer in cifs_readdir()
  cifs: fix race between call_async() and reconnect()
  cifs: Ratelimit kernel log messages
  iio: inkern: fix a NULL dereference on error
  iio: pressure: mpl115: fix temperature offset sign
  iio: light: acpi-als: Report data as processed
  iio: dac: mcp4725: set iio name property in sysfs
  iio: add IIO_TRIGGER dependency to STK8BA50
  iio: add HAS_IOMEM dependency to VF610_ADC
  iio-light: Use a signed return type for ltr501_match_samp_freq()
  iio:adc:ti_am335x_adc Fix buffered mode by identifying as software buffer.
  iio: adis_buffer: Fix out-of-bounds memory access
  scsi: fix soft lockup in scsi_remove_target() on module removal
  SCSI: Add Marvell Console to VPD blacklist
  scsi_dh_rdac: always retry MODE SELECT on command lock violation
  drivers/scsi/sg.c: mark VMA as VM_IO to prevent migration
  SCSI: fix crashes in sd and sr runtime PM
  iscsi-target: Fix potential dead-lock during node acl delete
  scsi: add Synology to 1024 sector blacklist
  klist: fix starting point removed bug in klist iterators
  tracepoints: Do not trace when cpu is offline
  tracing: Fix freak link error caused by branch tracer
  perf tools: tracepoint_error() can receive e=NULL, robustify it
  tools lib traceevent: Fix output of %llu for 64 bit values read on 32 bit machines
  ptrace: use fsuid, fsgid, effective creds for fs access checks
  Btrfs: fix direct IO requests not reporting IO error to user space
  Btrfs: fix hang on extent buffer lock caused by the inode_paths ioctl
  Btrfs: fix page reading in extent_same ioctl leading to csum errors
  Btrfs: fix invalid page accesses in extent_same (dedup) ioctl
  btrfs: properly set the termination value of ctx->pos in readdir
  Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()"
  Btrfs: fix fitrim discarding device area reserved for boot loader's use
  btrfs: handle invalid num_stripes in sys_array
  ext4: don't read blocks from disk after extents being swapped
  ext4: fix potential integer overflow
  ext4: fix scheduling in atomic on group checksum failure
  serial: omap: Prevent DoS using unprivileged ioctl(TIOCSRS485)
  serial: 8250_pci: Add Intel Broadwell ports
  tty: Add support for PCIe WCH382 2S multi-IO card
  pty: make sure super_block is still valid in final /dev/tty close
  pty: fix possible use after free of tty->driver_data
  staging/speakup: Use tty_ldisc_ref() for paste kworker
  phy: twl4030-usb: Fix unbalanced pm_runtime_enable on module reload
  phy: twl4030-usb: Relase usb phy on unload
  ALSA: seq: Fix double port list deletion
  ALSA: seq: Fix leak of pool buffer at concurrent writes
  ALSA: pcm: Fix rwsem deadlock for non-atomic PCM stream
  ALSA: hda - Cancel probe work instead of flush at remove
  x86/mm: Fix vmalloc_fault() to handle large pages properly
  x86/uaccess/64: Handle the caching of 4-byte nocache copies properly in __copy_user_nocache()
  x86/uaccess/64: Make the __copy_user_nocache() assembly code more readable
  x86/mm/pat: Avoid truncation when converting cpa->numpages to address
  x86/mm: Fix types used in pgprot cacheability flags translations
  Linux 4.4.2
  HID: multitouch: fix input mode switching on some Elan panels
  mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress
  zsmalloc: fix migrate_zspage-zs_free race condition
  zram: don't call idr_remove() from zram_remove()
  zram: try vmalloc() after kmalloc()
  zram/zcomp: use GFP_NOIO to allocate streams
  rtlwifi: rtl8821ae: Fix 5G failure when EEPROM is incorrectly encoded
  rtlwifi: rtl8821ae: Fix errors in parameter initialization
  crypto: marvell/cesa - fix test in mv_cesa_dev_dma_init()
  crypto: atmel-sha - remove calls of clk_prepare() from atomic contexts
  crypto: atmel-sha - fix atmel_sha_remove()
  crypto: algif_skcipher - Do not set MAY_BACKLOG on the async path
  crypto: algif_skcipher - Do not dereference ctx without socket lock
  crypto: algif_skcipher - Do not assume that req is unchanged
  crypto: user - lock crypto_alg_list on alg dump
  EVM: Use crypto_memneq() for digest comparisons
  crypto: algif_hash - wait for crypto_ahash_init() to complete
  crypto: shash - Fix has_key setting
  crypto: chacha20-ssse3 - Align stack pointer to 64 bytes
  crypto: caam - make write transactions bufferable on PPC platforms
  crypto: algif_skcipher - sendmsg SG marking is off by one
  crypto: algif_skcipher - Load TX SG list after waiting
  crypto: crc32c - Fix crc32c soft dependency
  crypto: algif_skcipher - Fix race condition in skcipher_check_key
  crypto: algif_hash - Fix race condition in hash_check_key
  crypto: af_alg - Forbid bind(2) when nokey child sockets are present
  crypto: algif_skcipher - Remove custom release parent function
  crypto: algif_hash - Remove custom release parent function
  crypto: af_alg - Allow af_af_alg_release_parent to be called on nokey path
  ahci: Intel DNV device IDs SATA
  libata: disable forced PORTS_IMPL for >= AHCI 1.3
  crypto: algif_skcipher - Add key check exception for cipher_null
  crypto: skcipher - Add crypto_skcipher_has_setkey
  crypto: algif_hash - Require setkey before accept(2)
  crypto: hash - Add crypto_ahash_has_setkey
  crypto: algif_skcipher - Add nokey compatibility path
  crypto: af_alg - Add nokey compatibility path
  crypto: af_alg - Fix socket double-free when accept fails
  crypto: af_alg - Disallow bind/setkey/... after accept(2)
  crypto: algif_skcipher - Require setkey before accept(2)
  sched: Fix crash in sched_init_numa()
  ext4 crypto: add missing locking for keyring_key access
  iommu/io-pgtable-arm: Ensure we free the final level on teardown
  tty: Fix unsafe ldisc reference via ioctl(TIOCGETD)
  tty: Retry failed reopen if tty teardown in-progress
  tty: Wait interruptibly for tty lock on reopen
  n_tty: Fix unsafe reference to "other" ldisc
  usb: xhci: apply XHCI_PME_STUCK_QUIRK to Intel Broxton-M platforms
  usb: xhci: handle both SSIC ports in PME stuck quirk
  usb: phy: msm: fix error handling in probe.
  usb: cdc-acm: send zero packet for intel 7260 modem
  usb: cdc-acm: handle unlinked urb in acm read callback
  USB: option: fix Cinterion AHxx enumeration
  USB: serial: option: Adding support for Telit LE922
  USB: cp210x: add ID for IAI USB to RS485 adaptor
  USB: serial: ftdi_sio: add support for Yaesu SCU-18 cable
  usb: hub: do not clear BOS field during reset device
  USB: visor: fix null-deref at probe
  USB: serial: visor: fix crash on detecting device without write_urbs
  ASoC: rt5645: fix the shift bit of IN1 boost
  saa7134-alsa: Only frees registered sound cards
  ALSA: dummy: Implement timer backend switching more safely
  ALSA: hda - Fix bad dereference of jack object
  ALSA: hda - Fix speaker output from VAIO AiO machines
  Revert "ALSA: hda - Fix noise on Gigabyte Z170X mobo"
  ALSA: hda - Fix static checker warning in patch_hdmi.c
  ALSA: hda - Add fixup for Mac Mini 7,1 model
  ALSA: timer: Fix race between stop and interrupt
  ALSA: timer: Fix wrong instance passed to slave callbacks
  ALSA: timer: Fix race at concurrent reads
  ALSA: timer: Fix link corruption due to double start or stop
  ALSA: timer: Fix leftover link at closing
  ALSA: timer: Code cleanup
  ALSA: seq: Fix lockdep warnings due to double mutex locks
  ALSA: seq: Fix race at closing in virmidi driver
  ALSA: seq: Fix yet another races among ALSA timer accesses
  ASoC: dpcm: fix the BE state on hw_free
  ALSA: pcm: Fix potential deadlock in OSS emulation
  ALSA: hda/realtek - Support Dell headset mode for ALC225
  ALSA: hda/realtek - Support headset mode for ALC225
  ALSA: hda/realtek - New codec support of ALC225
  ALSA: rawmidi: Fix race at copying & updating the position
  ALSA: rawmidi: Remove kernel WARNING for NULL user-space buffer check
  ALSA: rawmidi: Make snd_rawmidi_transmit() race-free
  ALSA: seq: Degrade the error message for too many opens
  ALSA: seq: Fix incorrect sanity check at snd_seq_oss_synth_cleanup()
  ALSA: dummy: Disable switching timer backend via sysfs
  ALSA: compress: Disable GET_CODEC_CAPS ioctl for some architectures
  ALSA: hda - disable dynamic clock gating on Broxton before reset
  ALSA: Add missing dependency on CONFIG_SND_TIMER
  ALSA: bebob: Use a signed return type for get_formation_index
  ALSA: usb-audio: avoid freeing umidi object twice
  ALSA: usb-audio: Add native DSD support for PS Audio NuWave DAC
  ALSA: usb-audio: Fix OPPO HA-1 vendor ID
  ALSA: usb-audio: Add quirk for Microsoft LifeCam HD-6000
  ALSA: usb-audio: Fix TEAC UD-501/UD-503/NT-503 usb delay
  hrtimer: Handle remaining time proper for TIME_LOW_RES
  md/raid: only permit hot-add of compatible integrity profiles
  media: i2c: Don't export ir-kbd-i2c module alias
  parisc: Fix __ARCH_SI_PREAMBLE_SIZE
  parisc: Protect huge page pte changes with spinlocks
  printk: do cond_resched() between lines while outputting to consoles
  tracing/stacktrace: Show entire trace if passed in function not found
  tracing: Fix stacktrace skip depth in trace_buffer_unlock_commit_regs()
  PCI: Fix minimum allocation address overwrite
  PCI: host: Mark PCIe/PCI (MSI) IRQ cascade handlers as IRQF_NO_THREAD
  mtd: nand: assign reasonable default name for NAND drivers
  wlcore/wl12xx: spi: fix NULL pointer dereference (Oops)
  wlcore/wl12xx: spi: fix oops on firmware load
  ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanup
  ocfs2/dlm: ignore cleaning the migration mle that is inuse
  ALSA: hda - Implement loopback control switch for Realtek and other codecs
  block: fix bio splitting on max sectors
  base/platform: Fix platform drivers with no probe callback
  HID: usbhid: fix recursive deadlock
  ocfs2: NFS hangs in __ocfs2_cluster_lock due to race with ocfs2_unblock_lock
  block: split bios to max possible length
  NFSv4.1/pnfs: Fixup an lo->plh_block_lgets imbalance in layoutreturn
  crypto: sun4i-ss - add missing statesize
  Linux 4.4.1
  arm64: kernel: fix architected PMU registers unconditional access
  arm64: kernel: enforce pmuserenr_el0 initialization and restore
  arm64: mm: ensure that the zero page is visible to the page table walker
  arm64: Clear out any singlestep state on a ptrace detach operation
  powerpc/module: Handle R_PPC64_ENTRY relocations
  scripts/recordmcount.pl: support data in text section on powerpc
  powerpc: Make {cmp}xchg* and their atomic_ versions fully ordered
  powerpc: Make value-returning atomics fully ordered
  powerpc/tm: Check for already reclaimed tasks
  batman-adv: Drop immediate orig_node free function
  batman-adv: Drop immediate batadv_hard_iface free function
  batman-adv: Drop immediate neigh_ifinfo free function
  batman-adv: Drop immediate batadv_neigh_node free function
  batman-adv: Drop immediate batadv_orig_ifinfo free function
  batman-adv: Avoid recursive call_rcu for batadv_nc_node
  batman-adv: Avoid recursive call_rcu for batadv_bla_claim
  team: Replace rcu_read_lock with a mutex in team_vlan_rx_kill_vid
  net/mlx5_core: Fix trimming down IRQ number
  bridge: fix lockdep addr_list_lock false positive splat
  ipv6: update skb->csum when CE mark is propagated
  net: bpf: reject invalid shifts
  phonet: properly unshare skbs in phonet_rcv()
  dwc_eth_qos: Fix dma address for multi-fragment skbs
  bonding: Prevent IPv6 link local address on enslaved devices
  net: preserve IP control block during GSO segmentation
  udp: disallow UFO for sockets with SO_NO_CHECK option
  net: pktgen: fix null ptr deref in skb allocation
  sched,cls_flower: set key address type when present
  tcp_yeah: don't set ssthresh below 2
  ipv6: tcp: add rcu locking in tcp_v6_send_synack()
  net: sctp: prevent writes to cookie_hmac_alg from accessing invalid memory
  vxlan: fix test which detect duplicate vxlan iface
  unix: properly account for FDs passed over unix sockets
  xhci: refuse loading if nousb is used
  usb: core: lpm: fix usb3_hardware_lpm sysfs node
  USB: cp210x: add ID for ELV Marble Sound Board 1
  rtlwifi: fix memory leak for USB device
  ASoC: compress: Fix compress device direction check
  ASoC: wm5110: Fix PGA clear when disabling DRE
  ALSA: timer: Handle disconnection more safely
  ALSA: hda - Flush the pending probe work at remove
  ALSA: hda - Fix missing module loading with model=generic option
  ALSA: hda - Fix bass pin fixup for ASUS N550JX
  ALSA: control: Avoid kernel warnings from tlv ioctl with numid 0
  ALSA: hrtimer: Fix stall by hrtimer_cancel()
  ALSA: pcm: Fix snd_pcm_hw_params struct copy in compat mode
  ALSA: seq: Fix snd_seq_call_port_info_ioctl in compat mode
  ALSA: hda - Add fixup for Dell Latitidue E6540
  ALSA: timer: Fix double unlink of active_list
  ALSA: timer: Fix race among timer ioctls
  ALSA: hda - fix the headset mic detection problem for a Dell laptop
  ALSA: timer: Harden slave timer list handling
  ALSA: usb-audio: Fix mixer ctl regression of Native Instrument devices
  ALSA: hda - Fix white noise on Dell Latitude E5550
  ALSA: seq: Fix race at timer setup and close
  ALSA: usb-audio: Avoid calling usb_autopm_put_interface() at disconnect
  ALSA: seq: Fix missing NULL check at remove_events ioctl
  ALSA: hda - Fixup inverted internal mic for Lenovo E50-80
  ALSA: usb: Add native DSD support for Oppo HA-1
  x86/mm: Improve switch_mm() barrier comments
  x86/mm: Add barriers and document switch_mm()-vs-flush synchronization
  x86/boot: Double BOOT_HEAP_SIZE to 64KB
  x86/reboot/quirks: Add iMac10,1 to pci_reboot_dmi_table[]
  kvm: x86: Fix vmwrite to SECONDARY_VM_EXEC_CONTROL
  KVM: x86: correctly print #AC in traces
  KVM: x86: expose MSR_TSC_AUX to userspace
  x86/xen: don't reset vcpu_info on a cancelled suspend
  KEYS: Fix keyring ref leak in join_session_keyring()

Conflicts:
	arch/arm64/kernel/perf_event.c
	drivers/scsi/sd.c
	sound/core/compress_offload.c

Change-Id: I9f77fe42aaae249c24cd6e170202110ab1426878
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
2016-03-23 20:51:00 -07:00
Se Wang (Patrick) Oh
1ee3c679cd mm: slub: call kasan_alloc_pages before freeing pages in slub
KASan marks slub objects as redzone and free and the bitmasks for
that region are not cleared until the pages are freed. When
CONFIG_PAGE_POISONING is enabled, as the pages still have special
bitmasks, KAsan report arises during pages poisoning. So mark the
pages as alloc status before poisoning the pages.
==================================================================
BUG: KASan: use after free in memset+0x24/0x44 at addr ffffffc0bb628000
Write of size 4096 by task kworker/u8:0/6
page:ffffffbacc51d900 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected
Call trace:
[<ffffffc00008c010>] dump_backtrace+0x0/0x250
[<ffffffc00008c270>] show_stack+0x10/0x1c
[<ffffffc001b6f9e4>] dump_stack+0x74/0xfc
[<ffffffc0002debf4>] kasan_report_error+0x2b0/0x408
[<ffffffc0002dee28>] kasan_report+0x34/0x40
[<ffffffc0002de240>] __asan_storeN+0x15c/0x168
[<ffffffc0002de47c>] memset+0x20/0x44
[<ffffffc0002d77bc>] kernel_map_pages+0x2e8/0x384
[<ffffffc000266458>] free_pages_prepare+0x340/0x3a0
[<ffffffc0002694cc>] __free_pages_ok+0x20/0x12c
[<ffffffc00026a698>] __free_pages+0x34/0x44
[<ffffffc00026ab3c>] __free_kmem_pages+0x8/0x14
[<ffffffc0002dc3fc>] kfree+0x114/0x254
[<ffffffc000b05748>] devres_free+0x48/0x5c
[<ffffffc000b05824>] devres_destroy+0x10/0x28
[<ffffffc000b05958>] devm_kfree+0x1c/0x3c
Memory state around the buggy address:
 ffffffc0bb627f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffc0bb627f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 >ffffffc0bb628000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                    ^
 ffffffc0bb628080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffffffc0bb628100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
BUG: KASan: use after free in memset+0x24/0x44 at addr ffffffc0bb2fe000
Write of size 4096 by task swapper/0/1
page:ffffffbacc4fdec0 count:0 mapcount:0 mapping:          (null) index:0xffffffc0bb2fe6a0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected
Call trace:
[<ffffffc00008c010>] dump_backtrace+0x0/0x250
[<ffffffc00008c270>] show_stack+0x10/0x1c
[<ffffffc001b6f9e4>] dump_stack+0x74/0xfc
[<ffffffc0002debf4>] kasan_report_error+0x2b0/0x408
[<ffffffc0002dee28>] kasan_report+0x34/0x40
[<ffffffc0002de240>] __asan_storeN+0x15c/0x168
[<ffffffc0002de47c>] memset+0x20/0x44
[<ffffffc0002d77bc>] kernel_map_pages+0x2e8/0x384
[<ffffffc000266458>] free_pages_prepare+0x340/0x3a0
[<ffffffc0002694cc>] __free_pages_ok+0x20/0x12c
[<ffffffc00026a698>] __free_pages+0x34/0x44
[<ffffffc0002d9c98>] __free_slab+0x15c/0x178
[<ffffffc0002d9d14>] discard_slab+0x60/0x6c
[<ffffffc0002dc034>] __slab_free+0x320/0x340
[<ffffffc0002dc224>] kmem_cache_free+0x1d0/0x25c
[<ffffffc0003bb608>] kernfs_put+0x2a0/0x3d8
Memory state around the buggy address:
 ffffffc0bb2fdf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffffffc0bb2fdf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffffffc0bb2fe000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
                   ^
 fffffc0bb2fe080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffffffc0bb2fe100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Change-Id: Id963b9439685f94a022dcdd60b59aaf126610387
Signed-off-by: Se Wang (Patrick) Oh <sewango@codeaurora.org>
[satyap: trivial merge conflict resolution]
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>
2016-03-22 11:10:45 -07:00
Andrey Ryabinin
788349f659 UBSAN: run-time undefined behavior sanity checker
UBSAN uses compile-time instrumentation to catch undefined behavior
(UB).  Compiler inserts code that perform certain kinds of checks before
operations that could cause UB.  If check fails (i.e.  UB detected)
__ubsan_handle_* function called to print error message.

So the most of the work is done by compiler.  This patch just implements
ubsan handlers printing errors.

GCC has this capability since 4.9.x [1] (see -fsanitize=undefined
option and its suboptions).
However GCC 5.x has more checkers implemented [2].
Article [3] has a bit more details about UBSAN in the GCC.

[1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
[2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
[3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/

Issues which UBSAN has found thus far are:

Found bugs:

 * out-of-bounds access - 97840cb67f ("netfilter: nfnetlink: fix
   insufficient validation in nfnetlink_bind")

undefined shifts:

 * d48458d4a7 ("jbd2: use a better hash function for the revoke
   table")

 * 10632008b9 ("clockevents: Prevent shift out of bounds")

 * 'x << -1' shift in ext4 -
   http://lkml.kernel.org/r/<5444EF21.8020501@samsung.com>

 * undefined rol32(0) -
   http://lkml.kernel.org/r/<1449198241-20654-1-git-send-email-sasha.levin@oracle.com>

 * undefined dirty_ratelimit calculation -
   http://lkml.kernel.org/r/<566594E2.3050306@odin.com>

 * undefined roundown_pow_of_two(0) -
   http://lkml.kernel.org/r/<1449156616-11474-1-git-send-email-sasha.levin@oracle.com>

 * [WONTFIX] undefined shift in __bpf_prog_run -
   http://lkml.kernel.org/r/<CACT4Y+ZxoR3UjLgcNdUm4fECLMx2VdtfrENMtRRCdgHB2n0bJA@mail.gmail.com>

   WONTFIX here because it should be fixed in bpf program, not in kernel.

signed overflows:

 * 32a8df4e0b ("sched: Fix odd values in effective_load()
   calculations")

 * mul overflow in ntp -
   http://lkml.kernel.org/r/<1449175608-1146-1-git-send-email-sasha.levin@oracle.com>

 * incorrect conversion into rtc_time in rtc_time64_to_tm() -
   http://lkml.kernel.org/r/<1449187944-11730-1-git-send-email-sasha.levin@oracle.com>

 * unvalidated timespec in io_getevents() -
   http://lkml.kernel.org/r/<CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com>

 * [NOTABUG] signed overflow in ktime_add_safe() -
   http://lkml.kernel.org/r/<CACT4Y+aJ4muRnWxsUe1CMnA6P8nooO33kwG-c8YZg=0Xc8rJqw@mail.gmail.com>

[akpm@linux-foundation.org: fix unused local warning]
[akpm@linux-foundation.org: fix __int128 build woes]
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yury Gribov <y.gribov@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-repo: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/
Git-commit: c6d308534aef6c99904bf5862066360ae067abc4
[tsoni@codeaurora.org: trivial merge conflict resolution]
CRs-Fixed: 969533
Change-Id: I048b9936b1120e0d375b7932c59de78d8ef8f411
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
[satyap@codeaurora.org: trivial merge conflict resolution]
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>
2016-03-22 11:09:57 -07:00
Susheel Khiani
793d80f988 mm: Update is_vmalloc_addr to account for vmalloc savings
is_vmalloc_addr currently assumes that all vmalloc addresses
exist between VMALLOC_START and VMALLOC_END. This may not be
the case when interleaving vmalloc and lowmem. Update the
is_vmalloc_addr to properly check for this.

Correspondingly we need to ensure that VMALLOC_TOTAL accounts
for all the vmalloc regions when CONFIG_ENABLE_VMALLOC_SAVING
is enabled.

Change-Id: I5def3d6ae1a4de59ea36f095b8c73649a37b1f36
Signed-off-by: Susheel Khiani <skhiani@codeaurora.org>
2016-03-22 11:03:59 -07:00
Susheel Khiani
c064333eac msm: Allow lowmem to be non contiguous and mixed
Currently on 32 bit systems, virtual space above
PAGE_OFFSET is reserved for direct mapped lowmem
and part of virtual address space is reserved for
vmalloc. We want to optimize such as to have as
much direct mapped memory as possible since there is
penalty for mapping/unmapping highmem. Now, we may
have an image that is expected to have a lifetime of
the entire system and is reserved in physical region
that would be part of direct mapped lowmem. The
physical memory which is thus reserved is never used
by Linux. This means that even though the system is
not actually accessing the  virtual memory
corresponding to the reserved physical memory, we
are still losing that portion of direct mapped lowmem
space.

So by allowing lowmem to be non contiguous we can
give this unused virtual address space of reserved
region back for use in vmalloc.

Change-Id: I980b3dfafac71884dcdcb8cd2e4a6363cde5746a
Signed-off-by: Susheel Khiani <skhiani@codeaurora.org>
2016-03-22 11:03:58 -07:00
Susheel Khiani
7215a1cfee msm: Increase the kernel virtual area to include lowmem
Even though lowmem is accounted for in vmalloc space,
allocation comes only from the region bounded by
VMALLOC_START and VMALLOC_END. The kernel virtual area
can now allocate from any unmapped region starting
from PAGE_OFFSET.

Change-Id: I291b9eb443d3f7445fd979bd7b09e9241ff22ba3
Signed-off-by: Neeti Desai <neetid@codeaurora.org>
Signed-off-by: Susheel Khiani <skhiani@codeaurora.org>
2016-03-22 11:03:56 -07:00
Vinayak Menon
8dd433c495 mm: showmem: make the notifiers atomic
There are places in kernel like the lowmemorykiller which
invokes show_mem_call_notifiers from an atomic context.
So move from a blocking notifier to atomic. At present
the notifier callbacks does not call sleeping functions,
but it should be made sure, it does not happen in future also.

Change-Id: I9668e67463ab8a6a60be55dbc86b88f45be8b041
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-03-22 11:03:55 -07:00
Vinayak Menon
3086328d5f mm: page-writeback: fix page state calculation in throttle_vm_writeout
It was found that a number of tasks were blocked in the reclaim path
(throttle_vm_writeout) for seconds, because of vmstat_diff not being
synced in time. Fix that by adding a new function
global_page_state_snapshot.

Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Change-Id: Iec167635ad724a55c27bdbd49eb8686e7857216c
2016-03-22 11:03:54 -07:00
Vinayak Menon
d487a9f1f7 mm: compaction: fix the page state calculation in too_many_isolated
Commit "mm: vmscan: fix the page state calculation in too_many_isolated"
fixed an issue where a number of tasks were blocked in reclaim path
for seconds, because of vmstat_diff not being synced in time.
A similar problem can happen in isolate_migratepages_block, where
similar calculation is performed. This patch fixes that.

Change-Id: Ie74f108ef770da688017b515fe37faea6f384589
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-03-22 11:03:54 -07:00
Vinayak Menon
910a8bd108 mm: vmpressure: account allocstalls only on higher pressures
At present any vmpressure value is scaled up if the pages are
reclaimed through direct reclaim. This can result in false
vmpressure values. Consider a case where a device is booted up
and most of the memory is occuppied by file pages. kswapd will
make sure that high watermark is maintained. Now when a sudden
huge allocation request comes in, the system will definitely
have to get into direct reclaims. The vmpressures can be very low,
but because of allocstall accounting logic even these low values
will be scaled to values nearing 100. This can result in
unnecessary LMK kills for example. So define a tunable threshold
for vmpressure above which the allocstalls will be accounted.

CRs-fixed: 893699
Change-Id: Idd7c6724264ac89f1f68f2e9d70a32390ffca3e5
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-03-22 11:03:53 -07:00
Vinayak Menon
e5ce54a9cb mm: swap: don't delay swap free for fast swap devices
There are couple of issues with swapcache usage when ZRAM is used
as swap device.
1) Kernel does a swap readahead which can be around 6 to 8 pages
depending on total ram, which is not required for zram since
accesses are fast.
2) Kernel delays the freeing up of swapcache expecting a later hit,
which again is useless in the case of zram.
3) This is not related to swapcache, but zram usage itself.
As mentioned in (2) kernel delays freeing of swapcache, but along with
that it delays zram compressed page free also. i.e. there can be 2 copies,
though one is compressed.

This patch addresses these issues using two new flags
QUEUE_FLAG_FAST and SWP_FAST, to indicate that accesses to the device
will be fast and cheap, and instructs the swap layer to free up
swap space agressively, and not to do read ahead.

Change-Id: I5d2d5176a5f9420300bb2f843f6ecbdb25ea80e4
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-03-22 11:03:52 -07:00
Vinayak Menon
0a8bf43567 mm: vmpressure: scale pressure based on reclaim context
The existing calculation of vmpressure takes into account only
the ratio of reclaimed to scanned pages, but not the time spent
or the difficulty in reclaiming those pages. For e.g. when there
are quite a number of file pages in the system, an allocation
request can be satisfied by reclaiming the file pages alone. If
such a reclaim is successful, the vmpressure value will remain low
irrespective of the time spent by the reclaim code to free up the
file pages. With a feature like lowmemorykiller, killing a task
can be faster than reclaiming the file pages alone. So if the
vmpressure values reflect the reclaim difficulty level, clients
can make a decision based on that, for e.g. to kill a task early.

This patch monitors the number of pages scanned in the direct
reclaim path and scales the vmpressure level according to that.

Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Change-Id: I6e643d29a9a1aa0814309253a8b690ad86ec0b13
2016-03-22 11:03:51 -07:00
Vinayak Menon
fb880fe5d1 mm: vmpressure: allow in-kernel clients to subscribe for events
Currently, vmpressure is tied to memcg and its events are
available only to userspace clients. This patch removes
the dependency on CONFIG_MEMCG and adds a mechanism for
in-kernel clients to subscribe for vmpressure events (in
fact raw vmpressure values are delivered instead of vmpressure
levels, to provide clients more flexibility to take actions
on custom pressure levels which are not currently defined
by vmpressure module).

Change-Id: I38010f166546e8d7f12f5f355b5dbfd6ba04d587
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-03-22 11:03:50 -07:00
Liam Mark
a886f65ded mm/Kconfig: support forcing allocators to return ZONE_DMA memory
Add a new config item, CONFIG_FORCE_ALLOC_FROM_DMA_ZONE, which
can be used to optionally force certain allocators to always
return memory from ZONE_DMA.

This option helps ensure that clients who require ZONE_DMA
memory are always using ZONE_DMA memory.

Change-Id: Id2d36214307789f27aa775c2bef2dab5047c4ff0
Signed-off-by: Liam Mark <lmark@codeaurora.org>
2016-03-22 11:03:49 -07:00
Vignesh Radhakrishnan
12471ac6f8 kmemleak : Make kmemleak_stack_scan optional using config
Currently we have kmemleak_stack_scan enabled by default.
This can hog the cpu with pre-emption disabled for a long
time starving other tasks.

Make this optional at compile time, since if required
we can always write to sysfs entry and enable this option.

Change-Id: Ie30447861c942337c7ff25ac269b6025a527e8eb
Signed-off-by: Vignesh Radhakrishnan <vigneshr@codeaurora.org>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
2016-03-22 11:03:47 -07:00
Se Wang (Patrick) Oh
ab5d4ae2e4 mm: switch KASan hook calling order in page alloc/free path
When CONFIG_PAGE_POISONING is enabled, the pages are poisoned
after setting free page in KASan Shadow memory and KASan reports
the read after free warning. The same thing happens in the allocation
path. So change the order of calling KASan_alloc/free API so that
pages poisoning happens when the pages are in alloc status in KASan
shadow memory.
following is the KASan report for reference.
==================================================================
BUG: KASan: use after free in memset+0x24/0x44 at addr ffffffc000000000
Write of size 4096 by task swapper/0
page:ffffffbac5000000 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x0()
page dumped because: kasan: bad access detected
CPU: 0 PID: 0 Comm: swapper Not tainted 3.18.0-g5a4a5d5-07242-g6938a8b-dirty #1
Hardware name: Qualcomm Technologies, Inc. MSM 8996 v2 + PMI8994 MTP (DT)
Call trace:
[<ffffffc000089ea4>] dump_backtrace+0x0/0x1c4
[<ffffffc00008a078>] show_stack+0x10/0x1c
[<ffffffc0010ecfd8>] dump_stack+0x74/0xc8
[<ffffffc00020faec>] kasan_report_error+0x2b0/0x408
[<ffffffc00020fd20>] kasan_report+0x34/0x40
[<ffffffc00020f138>] __asan_storeN+0x15c/0x168
[<ffffffc00020f374>] memset+0x20/0x44
[<ffffffc0002086e0>] kernel_map_pages+0x238/0x2a8
[<ffffffc0001ba738>] free_pages_prepare+0x21c/0x25c
[<ffffffc0001bc7e4>] __free_pages_ok+0x20/0xf0
[<ffffffc0001bd3bc>] __free_pages+0x34/0x44
[<ffffffc0001bd5d8>] __free_pages_bootmem+0xf4/0x110
[<ffffffc001ca9050>] free_all_bootmem+0x160/0x1f4
[<ffffffc001c97b30>] mem_init+0x70/0x1ec
[<ffffffc001c909f8>] start_kernel+0x2b8/0x4e4
[<ffffffc001c987dc>] kasan_early_init+0x154/0x160

Change-Id: Idbd3dc629be57ed55a383b069a735ae3ee7b9f05
Signed-off-by: Se Wang (Patrick) Oh <sewango@codeaurora.org>
2016-03-22 11:03:46 -07:00
Lee Susman
34144c841b mm: change initial readahead window size calculation
Change the logic which determines the initial readahead window size
such that for small requests (one page) the initial window size
will be x4 the size of the original request, regardless of the
VM_MAX_READAHEAD value. This prevents a rapid ramp-up
that could be caused due to increasing VM_MAX_READAHEAD.

Change-Id: I93d59c515d7e6c6d62348790980ff7bd4f434997
Signed-off-by: Lee Susman <lsusman@codeaurora.org>
2016-03-22 11:03:39 -07:00
Liam Mark
78ec19c5f9 mm: split_free_page ignore memory watermarks for CMA
Memory watermarks were sometimes preventing CMA allocations
in low memory.

Change-Id: I550ec987cbd6bc6dadd72b4a764df20cd0758479
Signed-off-by: Liam Mark <lmark@codeaurora.org>
2016-03-22 11:03:38 -07:00
Laura Abbott
81f6201534 mm: Don't put CMA pages on per cpu lists
CMA allocations rely on being able to migrate pages out
quickly to fulfill the allocations. Most use cases for
movable allocations meet this requirement. File system
allocations may take an unaccpetably long time to
migrate, which creates delays from CMA. Prevent CMA
pages from ending up on the per-cpu lists to avoid
code paths grabbing CMA pages on the fast path. CMA
pages can still be allocated as a fallback under tight
memory pressure.

CRs-Fixed: 452508
Change-Id: I79a28f697275a2a1870caabae53c8ea345b4b47d
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
2016-03-22 11:03:38 -07:00
Laura Abbott
e48a20a27c mm: Add is_cma_pageblock definition
Bring back the is_cma_pageblock definition for determining if a
page is CMA or not.

Change-Id: I39fd546e22e240b752244832c79514f109c8e84b
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
2016-03-22 11:03:37 -07:00
Liam Mark
8918861861 mm: vmscan: support setting of kswapd cpu affinity
Allow the kswapd cpu affinity to be configured.
There can be power benefits on certain targets when limiting kswapd
to run only on certain cores.

CRs-fixed: 752344
Change-Id: I8a83337ff313a7e0324361140398226a09f8be0f
Signed-off-by: Liam Mark <lmark@codeaurora.org>
[imaund@codeaurora.org: Resolved trivial context conflicts.]
Signed-off-by: Ian Maund <imaund@codeaurora.org>
2016-03-22 11:03:36 -07:00
Vinayak Menon
90863369e5 mm: vmscan: lock page on swap error in pageout
A workaround was added ealier to move a page to active
list if swapping to devices like zram fails. But this
can result in try_to_free_swap being called from
shrink_page_list, without a properly locked page.
Lock the page when we indicate to activate a page
in pageout().
Add a check to ensure that error is on swap, and
clear the error flag before moving the page to
active list.

CRs-fixed: 760049
Change-Id: I77a8bbd6ed13efdec943298fe9448412feeac176
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-03-22 11:03:35 -07:00
Liam Mark
8a94faffd0 mm: vmscan: support complete shrinker reclaim
Ensure that shrinkers are given the option to completely drop
their caches even when their caches are smaller than the batch size.

This change helps improve memory headroom by ensuring that under
significant memory pressure shrinkers can drop all of their caches.

This change only attempts to more aggressively call the shrinkers
during background memory reclaim, inorder to avoid hurting the
perforamnce of direct memory reclaim.

Change-Id: I8dbc29c054add639e4810e36fd2c8a063e5c52f3
Signed-off-by: Liam Mark <lmark@codeaurora.org>
2016-03-22 11:03:33 -07:00
David Keitel
747b0dceae mm: slub: panic for object and slab errors
If the SLUB_DEBUG_PANIC_ON Kconfig option is
selected, also panic for object and slab
errors to allow capturing relevant debug
data.

Change-Id: Idc582ef48d3c0d866fa89cf8660ff0a5402f7e15
Signed-off-by: David Keitel <dkeitel@codeaurora.org>
2016-03-22 11:03:32 -07:00
David Keitel
a31c7a448b defconfig: 8994: enable CONFIG_DEBUG_SLUB_PANIC_ON
Add the DEBUG_SLUB_PANIC_ON option to KCONFIG preventing
the existing defconfig option from being overwritten
by make config.

This will induce a panic if slab debug catches corruptions
within the padding of a given object.

The intention here is to induce collection of data
immediately after the corruption is detected with
the goal to catch the possible source of the corruption.

Change-Id: Ide0102d0761022c643a761989360ae5c853870a8
Signed-off-by: David Keitel <dkeitel@codeaurora.org>
[imaund@codeaurora.org: Resolved trivial merge conflicts.]
Signed-off-by: Ian Maund <imaund@codeaurora.org>
[lmark@codeaurora.org: ensure change does not create
 arch/arm64/configs/msm8994_defconfig file]
Signed-off-by: Liam Mark <lmark@codeaurora.org>
2016-03-22 11:03:31 -07:00
Abhimanyu Garg
4f98dec419 KSM: Start KSM by default
Strat running KSM by default at device bootup.

Change-Id: I7926c529ea42675f4279bffaf149a0cf1080d61b
Signed-off-by: Abhimanyu Garg <agarg@codeaurora.org>
2016-03-22 11:03:30 -07:00
Liam Mark
71edb92d82 mm, oom: make dump_tasks public
Allow other functions to dump the list of tasks.
Useful for when debugging memory leaks.

Change-Id: I76c33a118a9765b4c2276e8c76de36399c78dbf6
Signed-off-by: Liam Mark <lmark@codeaurora.org>
2016-03-22 11:03:30 -07:00
Laura Abbott
1fe8bfe88a ksm: Add showmem notifier
KSM is yet another framework which may obfuscate some memory
problems. Use the showmem notifier to show how KSM is being
used to give some insight into potential issues or non-issues.

Change-Id: If82405dc33f212d085e6847f7c511fd4d0a32a10
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
2016-03-22 11:03:28 -07:00
David Keitel
c5eff6c321 mm: slub: Panic instead of restoring corrupted bytes
Resiliency of slub was added for production systems in an
attempt to restore corruptions and allow production environments
to continue to run.

In debug setups, this may no be desirable. Thus rather than
attempting to restore corrupted bytes in poisoned zones, panic
to attempt to catch more context of what was going on in the
system at the time.

Add the CONFIG_SLUB_DEBUG_PANIC_ON defconfig option to allow
debug builds to turn on this panic option.

Change-Id: I01763e8eea40a4544e9b7e48c4e4d40840b6c82d
Signed-off-by: David Keitel <dkeitel@codeaurora.org>
2016-03-22 11:03:27 -07:00
Chintan Pandya
9ec1d6c8e5 ksm: Provide support to use deferred timers for scanner thread
KSM thread to scan pages is getting schedule on definite timeout.
That wakes up CPU from idle state and hence may affect the power
consumption. Provide an optional support to use deferred timer
which suites low-power use-cases.

To enable deferred timers,
$ echo 1 > /sys/kernel/mm/ksm/deferred_timer

Change-Id: I07fe199f97fe1f72f9a9e1b0b757a3ac533719e8
Signed-off-by: Chintan Pandya <cpandya@codeaurora.org>
2016-03-22 11:03:27 -07:00
Liam Mark
585690954e mm: vmscan: support equal reclaim for anon and file pages
When performing memory reclaim support treating anonymous and
file backed pages equally.

Swapping anonymous pages out to memory can be efficient enough
to justify treating anonymous and file backed pages equally.

CRs-Fixed: 648984
Change-Id: I6315b8557020d1e27a34225bb9cefbef1fb43266
Signed-off-by: Liam Mark <lmark@codeaurora.org>
2016-03-22 11:03:26 -07:00
Olav Haugan
80370b5f59 mm: vmscan: Move pages that fail swapout to LRU active list
Move pages that fail swapout to the LRU active list to reduce
pressure on swap device when swapping out is already failing.
This helps when using a pseudo swap device such as zram which
starts failing when memory is low.

Change-Id: Ib136cd0a744378aa93d837a24b9143ee818c80b3
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
2016-03-22 11:03:25 -07:00
Laura Abbott
a7470fb452 mm: Remove __init annotations from free_bootmem_late
free_bootmem_late is currently set up to only be used in init
functions. Some clients need to use this function past initcalls.
The functions themselves have no restrictions on being used later
minus the __init annotations so remove the annotation.

Change-Id: I7c7e15cf2780a8843ebb4610da5b633c9abb0b3d
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
[abhimany@codeaurora.org: resolve minor conflict
and remove __init from nobootmem.c]
Signed-off-by: Abhimanyu Kapur <abhimany@codeaurora.org>
2016-03-22 11:03:23 -07:00
Laura Abbott
8f13b60413 mm: Mark free pages as read only
Drivers have a tendency to scribble on everything, including free
pages. Make life easier by marking free pages as read only when
on the buddy list and re-marking as read/write when allocating.

Change-Id: I978ed2921394919917307b9c99217fdc22f82c59
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
(cherry picked from commit 752f5aecb0511c4d661dce2538c723675c1e6449)
2016-03-22 11:03:20 -07:00
Laura Abbott
416cca9db2 mm: Add notifier framework for showing memory
There are many drivers in the kernel which can hold on
to lots of memory. It can be useful to dump out all those
drivers at key points in the kernel. Introduct a notifier
framework for dumping this information. When the notifiers
are called, drivers can dump out the state of any memory
they may be using.

Change-Id: Ifb2946964bf5d072552dd56d8d6dfdd794af6d84
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
2016-03-22 11:03:15 -07:00
Stephen Boyd
75defbf367 memblock: Add memblock_overlaps_memory()
Add a new function, memblock_overlaps_memory(), to check if a
region overlaps with a memory bank. This will be used by
peripheral loader code to detect when kernel memory would be
overwritten.

Change-Id: I851f8f416a0f36e85c0e19536b5209f7d4bd431c
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
(cherry picked from commit cc2753448d9f2adf48295f935a7eee36023ba8d3)
Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
2016-03-22 11:03:13 -07:00
Vineet Gupta
edfde263bd mm,thp: khugepaged: call pte flush at the time of collapse
commit 6a6ac72fd6ea32594b316513e1826c3f6db4cc93 upstream.

This showed up on ARC when running LMBench bw_mem tests as Overlapping
TLB Machine Check Exception triggered due to STLB entry (2M pages)
overlapping some NTLB entry (regular 8K page).

bw_mem 2m touches a large chunk of vaddr creating NTLB entries.  In the
interim khugepaged kicks in, collapsing the contiguous ptes into a
single pmd.  pmdp_collapse_flush()->flush_pmd_tlb_range() is called to
flush out NTLB entries for the ptes.  This for ARC (by design) can only
shootdown STLB entries (for pmd).  The stray NTLB entries cause the
overlap with the subsequent STLB entry for collapsed page.  So make
pmdp_collapse_flush() call pte flush interface not pmd flush.

Note that originally all thp flush call sites in generic code called
flush_tlb_range() leaving it to architecture to implement the flush for
pte and/or pmd.  Commit 12ebc1581a changed this by calling a new
opt-in API flush_pmd_tlb_range() which made the semantics more explicit
but failed to distinguish the pte vs pmd flush in generic code, which is
what this patch fixes.

Note that ARC can fixed w/o touching the generic pmdp_collapse_flush()
by defining a ARC version, but that defeats the purpose of generic
version, plus sementically this is the right thing to do.

Fixes STAR 9000961194: LMBench on AXS103 triggering duplicate TLB
exceptions with super pages

Fixes: 12ebc1581a ("mm,thp: introduce flush_pmd_tlb_range")
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25 12:01:23 -08:00
Martijn Coenen
ececa3ebe2 memcg: only free spare array when readers are done
commit 6611d8d76132f86faa501de9451a89bf23fb2371 upstream.

A spare array holding mem cgroup threshold events is kept around to make
sure we can always safely deregister an event and have an array to store
the new set of events in.

In the scenario where we're going from 1 to 0 registered events, the
pointer to the primary array containing 1 event is copied to the spare
slot, and then the spare slot is freed because no events are left.
However, it is freed before calling synchronize_rcu(), which means
readers may still be accessing threshold->primary after it is freed.

Fixed by only freeing after synchronize_rcu().

Signed-off-by: Martijn Coenen <maco@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25 12:01:22 -08:00
Kirill A. Shutemov
d1f8217a9a mm: fix regression in remap_file_pages() emulation
commit 48f7df329474b49d83d0dffec1b6186647f11976 upstream.

Grazvydas Ignotas has reported a regression in remap_file_pages()
emulation.

Testcase:
	#define _GNU_SOURCE
	#include <assert.h>
	#include <stdlib.h>
	#include <stdio.h>
	#include <sys/mman.h>

	#define SIZE    (4096 * 3)

	int main(int argc, char **argv)
	{
		unsigned long *p;
		long i;

		p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE,
				MAP_SHARED | MAP_ANONYMOUS, -1, 0);
		if (p == MAP_FAILED) {
			perror("mmap");
			return -1;
		}

		for (i = 0; i < SIZE / 4096; i++)
			p[i * 4096 / sizeof(*p)] = i;

		if (remap_file_pages(p, 4096, 0, 1, 0)) {
			perror("remap_file_pages");
			return -1;
		}

		if (remap_file_pages(p, 4096 * 2, 0, 1, 0)) {
			perror("remap_file_pages");
			return -1;
		}

		assert(p[0] == 1);

		munmap(p, SIZE);

		return 0;
	}

The second remap_file_pages() fails with -EINVAL.

The reason is that remap_file_pages() emulation assumes that the target
vma covers whole area we want to over map.  That assumption is broken by
first remap_file_pages() call: it split the area into two vma.

The solution is to check next adjacent vmas, if they map the same file
with the same flags.

Fixes: c8d78c1823 ("mm: replace remap_file_pages() syscall with emulation")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Grazvydas Ignotas <notasas@gmail.com>
Tested-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25 12:01:21 -08:00
Konstantin Khlebnikov
413aab16bc mm: replace vma_lock_anon_vma with anon_vma_lock_read/write
commit 12352d3cae2cebe18805a91fab34b534d7444231 upstream.

Sequence vma_lock_anon_vma() - vma_unlock_anon_vma() isn't safe if
anon_vma appeared between lock and unlock.  We have to check anon_vma
first or call anon_vma_prepare() to be sure that it's here.  There are
only few users of these legacy helpers.  Let's get rid of them.

This patch fixes anon_vma lock imbalance in validate_mm().  Write lock
isn't required here, read lock is enough.

And reorders expand_downwards/expand_upwards: security_mmap_addr() and
wrapping-around check don't have to be under anon vma lock.

Link: https://lkml.kernel.org/r/CACT4Y+Y908EjM2z=706dv4rV6dWtxTLK9nFg9_7DhRMLppBo2g@mail.gmail.com
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25 12:01:21 -08:00
Kirill A. Shutemov
918a2c388e mm: fix mlock accouting
commit 7162a1e87b3e380133dadc7909081bb70d0a7041 upstream.

Tetsuo Handa reported underflow of NR_MLOCK on munlock.

Testcase:

    #include <stdio.h>
    #include <stdlib.h>
    #include <sys/mman.h>

    #define BASE ((void *)0x400000000000)
    #define SIZE (1UL << 21)

    int main(int argc, char *argv[])
    {
        void *addr;

        system("grep Mlocked /proc/meminfo");
        addr = mmap(BASE, SIZE, PROT_READ | PROT_WRITE,
                MAP_ANONYMOUS | MAP_PRIVATE | MAP_LOCKED | MAP_FIXED,
                -1, 0);
        if (addr == MAP_FAILED)
            printf("mmap() failed\n"), exit(1);
        munmap(addr, SIZE);
        system("grep Mlocked /proc/meminfo");
        return 0;
    }

It happens on munlock_vma_page() due to unfortunate choice of nr_pages
data type:

    __mod_zone_page_state(zone, NR_MLOCK, -nr_pages);

For unsigned int nr_pages, implicitly casted to long in
__mod_zone_page_state(), it becomes something around UINT_MAX.

munlock_vma_page() usually called for THP as small pages go though
pagevec.

Let's make nr_pages signed int.

Similar fixes in 6cdb18ad98 ("mm/vmstat: fix overflow in
mod_zone_page_state()") used `long' type, but `int' here is OK for a
count of the number of sub-pages in a huge page.

Fixes: ff6a6da60b ("mm: accelerate munlock() treatment of THP pages")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Michel Lespinasse <walken@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25 12:01:21 -08:00
Naoya Horiguchi
bd55913cf2 mm: soft-offline: check return value in second __get_any_page() call
commit d96b339f453997f2f08c52da3f41423be48c978f upstream.

I saw the following BUG_ON triggered in a testcase where a process calls
madvise(MADV_SOFT_OFFLINE) on thps, along with a background process that
calls migratepages command repeatedly (doing ping-pong among different
NUMA nodes) for the first process:

   Soft offlining page 0x60000 at 0x700000600000
   __get_any_page: 0x60000 free buddy page
   page:ffffea0001800000 count:0 mapcount:-127 mapping:          (null) index:0x1
   flags: 0x1fffc0000000000()
   page dumped because: VM_BUG_ON_PAGE(atomic_read(&page->_count) == 0)
   ------------[ cut here ]------------
   kernel BUG at /src/linux-dev/include/linux/mm.h:342!
   invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
   Modules linked in: cfg80211 rfkill crc32c_intel serio_raw virtio_balloon i2c_piix4 virtio_blk virtio_net ata_generic pata_acpi
   CPU: 3 PID: 3035 Comm: test_alloc_gene Tainted: G           O    4.4.0-rc8-v4.4-rc8-160107-1501-00000-rc8+ #74
   Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
   task: ffff88007c63d5c0 ti: ffff88007c210000 task.ti: ffff88007c210000
   RIP: 0010:[<ffffffff8118998c>]  [<ffffffff8118998c>] put_page+0x5c/0x60
   RSP: 0018:ffff88007c213e00  EFLAGS: 00010246
   Call Trace:
     put_hwpoison_page+0x4e/0x80
     soft_offline_page+0x501/0x520
     SyS_madvise+0x6bc/0x6f0
     entry_SYSCALL_64_fastpath+0x12/0x6a
   Code: 8b fc ff ff 5b 5d c3 48 89 df e8 b0 fa ff ff 48 89 df 31 f6 e8 c6 7d ff ff 5b 5d c3 48 c7 c6 08 54 a2 81 48 89 df e8 a4 c5 01 00 <0f> 0b 66 90 66 66 66 66 90 55 48 89 e5 41 55 41 54 53 48 8b 47
   RIP  [<ffffffff8118998c>] put_page+0x5c/0x60
    RSP <ffff88007c213e00>

The root cause resides in get_any_page() which retries to get a refcount
of the page to be soft-offlined.  This function calls
put_hwpoison_page(), expecting that the target page is putback to LRU
list.  But it can be also freed to buddy.  So the second check need to
care about such case.

Fixes: af8fae7c08 ("mm/memory-failure.c: clean up soft_offline_page()")
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25 12:01:21 -08:00
Jann Horn
969624b7c1 ptrace: use fsuid, fsgid, effective creds for fs access checks
commit caaee6234d05a58c5b4d05e7bf766131b810a657 upstream.

By checking the effective credentials instead of the real UID / permitted
capabilities, ensure that the calling process actually intended to use its
credentials.

To ensure that all ptrace checks use the correct caller credentials (e.g.
in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS
flag), use two new flags and require one of them to be set.

The problem was that when a privileged task had temporarily dropped its
privileges, e.g.  by calling setreuid(0, user_uid), with the intent to
perform following syscalls with the credentials of a user, it still passed
ptrace access checks that the user would not be able to pass.

While an attacker should not be able to convince the privileged task to
perform a ptrace() syscall, this is a problem because the ptrace access
check is reused for things in procfs.

In particular, the following somewhat interesting procfs entries only rely
on ptrace access checks:

 /proc/$pid/stat - uses the check for determining whether pointers
     should be visible, useful for bypassing ASLR
 /proc/$pid/maps - also useful for bypassing ASLR
 /proc/$pid/cwd - useful for gaining access to restricted
     directories that contain files with lax permissions, e.g. in
     this scenario:
     lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar
     drwx------ root root /root
     drwxr-xr-x root root /root/foobar
     -rw-r--r-- root root /root/foobar/secret

Therefore, on a system where a root-owned mode 6755 binary changes its
effective credentials as described and then dumps a user-specified file,
this could be used by an attacker to reveal the memory layout of root's
processes or reveal the contents of files he is not allowed to access
(through /proc/$pid/cwd).

[akpm@linux-foundation.org: fix warning]
Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25 12:01:16 -08:00
Tetsuo Handa
fe5c164ef3 mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress
commit 564e81a57f9788b1475127012e0fd44e9049e342 upstream.

Jan Stancek has reported that system occasionally hanging after "oom01"
testcase from LTP triggers OOM.  Guessing from a result that there is a
kworker thread doing memory allocation and the values between "Node 0
Normal free:" and "Node 0 Normal:" differs when hanging, vmstat is not
up-to-date for some reason.

According to commit 373ccbe592 ("mm, vmstat: allow WQ concurrency to
discover memory reclaim doesn't make any progress"), it meant to force
the kworker thread to take a short sleep, but it by error used
schedule_timeout(1).  We missed that schedule_timeout() in state
TASK_RUNNING doesn't do anything.

Fix it by using schedule_timeout_uninterruptible(1) which forces the
kworker thread to take a short sleep in order to make sure that vmstat
is up-to-date.

Fixes: 373ccbe592 ("mm, vmstat: allow WQ concurrency to discover memory reclaim doesn't make any progress")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Cristopher Lameter <clameter@sgi.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Arkadiusz Miskiewicz <arekm@maven.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-17 12:31:06 -08:00
Junil Lee
bddaf79195 zsmalloc: fix migrate_zspage-zs_free race condition
commit c102f07ca0b04f2cb49cfc161c83f6239d17f491 upstream.

record_obj() in migrate_zspage() does not preserve handle's
HANDLE_PIN_BIT, set by find_aloced_obj()->trypin_tag(), and implicitly
(accidentally) un-pins the handle, while migrate_zspage() still performs
an explicit unpin_tag() on the that handle.  This additional explicit
unpin_tag() introduces a race condition with zs_free(), which can pin
that handle by this time, so the handle becomes un-pinned.

Schematically, it goes like this:

  CPU0                                        CPU1
  migrate_zspage
    find_alloced_obj
      trypin_tag
        set HANDLE_PIN_BIT                    zs_free()
                                                pin_tag()
  obj_malloc() -- new object, no tag
  record_obj() -- remove HANDLE_PIN_BIT           set HANDLE_PIN_BIT
  unpin_tag()  -- remove zs_free's HANDLE_PIN_BIT

The race condition may result in a NULL pointer dereference:

  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  CPU: 0 PID: 19001 Comm: CookieMonsterCl Tainted:
  PC is at get_zspage_mapping+0x0/0x24
  LR is at obj_free.isra.22+0x64/0x128
  Call trace:
     get_zspage_mapping+0x0/0x24
     zs_free+0x88/0x114
     zram_free_page+0x64/0xcc
     zram_slot_free_notify+0x90/0x108
     swap_entry_free+0x278/0x294
     free_swap_and_cache+0x38/0x11c
     unmap_single_vma+0x480/0x5c8
     unmap_vmas+0x44/0x60
     exit_mmap+0x50/0x110
     mmput+0x58/0xe0
     do_exit+0x320/0x8dc
     do_group_exit+0x44/0xa8
     get_signal+0x538/0x580
     do_signal+0x98/0x4b8
     do_notify_resume+0x14/0x5c

This patch keeps the lock bit in migration path and update value
atomically.

Signed-off-by: Junil Lee <junil0814.lee@lge.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-17 12:31:06 -08:00
dcashman
d49d88766b FROMLIST: mm: mmap: Add new /proc tunable for mmap_base ASLR.
(cherry picked from commit https://lkml.org/lkml/2015/12/21/337)

ASLR  only uses as few as 8 bits to generate the random offset for the
mmap base address on 32 bit architectures. This value was chosen to
prevent a poorly chosen value from dividing the address space in such
a way as to prevent large allocations. This may not be an issue on all
platforms. Allow the specification of a minimum number of bits so that
platforms desiring greater ASLR protection may determine where to place
the trade-off.

Bug: 24047224
Signed-off-by: Daniel Cashman <dcashman@android.com>
Signed-off-by: Daniel Cashman <dcashman@google.com>
Change-Id: Ibf9ed3d4390e9686f5cc34f605d509a20d40e6c2
2016-02-16 13:54:14 -08:00
Colin Cross
586278d78b mm: add a field to store names for private anonymous memory
Userspace processes often have multiple allocators that each do
anonymous mmaps to get memory.  When examining memory usage of
individual processes or systems as a whole, it is useful to be
able to break down the various heaps that were allocated by
each layer and examine their size, RSS, and physical memory
usage.

This patch adds a user pointer to the shared union in
vm_area_struct that points to a null terminated string inside
the user process containing a name for the vma.  vmas that
point to the same address will be merged, but vmas that
point to equivalent strings at different addresses will
not be merged.

Userspace can set the name for a region of memory by calling
prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, start, len, (unsigned long)name);
Setting the name to NULL clears it.

The names of named anonymous vmas are shown in /proc/pid/maps
as [anon:<name>] and in /proc/pid/smaps in a new "Name" field
that is only present for named vmas.  If the userspace pointer
is no longer valid all or part of the name will be replaced
with "<fault>".

The idea to store a userspace pointer to reduce the complexity
within mm (at the expense of the complexity of reading
/proc/pid/mem) came from Dave Hansen.  This results in no
runtime overhead in the mm subsystem other than comparing
the anon_name pointers when considering vma merging.  The pointer
is stored in a union with fieds that are only used on file-backed
mappings, so it does not increase memory usage.

Includes fix from Jed Davis <jld@mozilla.com> for typo in
prctl_set_vma_anon_name, which could attempt to set the name
across two vmas at the same time due to a typo, which might
corrupt the vma list.  Fix it to use tmp instead of end to limit
the name setting to a single vma at a time.

Change-Id: I9aa7b6b5ef536cd780599ba4e2fba8ceebe8b59f
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
2016-02-16 13:54:13 -08:00
Rik van Riel
f8ade3666c add extra free kbytes tunable
Add a userspace visible knob to tell the VM to keep an extra amount
of memory free, by increasing the gap between each zone's min and
low watermarks.

This is useful for realtime applications that call system
calls and have a bound on the number of allocations that happen
in any short time period.  In this application, extra_free_kbytes
would be left at an amount equal to or larger than than the
maximum number of allocations that happen in any burst.

It may also be useful to reduce the memory use of virtual
machines (temporarily?), in a way that does not cause memory
fragmentation like ballooning does.

[ccross]
Revived for use on old kernels where no other solution exists.
The tunable will be removed on kernels that do better at avoiding
direct reclaim.

Change-Id: I765a42be8e964bfd3e2886d1ca85a29d60c3bb3e
Signed-off-by: Rik van Riel<riel@redhat.com>
Signed-off-by: Colin Cross <ccross@android.com>
2016-02-16 13:54:12 -08:00
Rebecca Schultz Zavin
b0e7a582b2 mm: vmscan: Add a debug file for shrinkers
This patch adds a debugfs file called "shrinker" when read this calls
all the shrinkers in the system with nr_to_scan set to zero and prints
the result.  These results are the number of objects the shrinkers have
available and can thus be used an indication of the total memory
that would be availble to the system if a shrink occurred.

Change-Id: Ied0ee7caff3d2fc1cb4bb839aaafee81b5b0b143
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
2016-02-16 13:54:12 -08:00
Martijn Coenen
e212fc789a UPSTREAM: memcg: Only free spare array when readers are done
A spare array holding mem cgroup threshold events is kept around
to make sure we can always safely deregister an event and have an
array to store the new set of events in.

In the scenario where we're going from 1 to 0 registered events, the
pointer to the primary array containing 1 event is copied to the spare
slot, and then the spare slot is freed because no events are left.
However, it is freed before calling synchronize_rcu(), which means
readers may still be accessing threshold->primary after it is freed.

Fixed by only freeing after synchronize_rcu().

Signed-off-by: Martijn Coenen <maco@google.com>
2016-02-16 13:53:47 -08:00