Commit Graph

470 Commits

Author SHA1 Message Date
Al Viro
4d430bf85d Hang/soft lockup in d_invalidate with simultaneous calls
commit 81be24d263 upstream.

It's not hard to trigger a bunch of d_invalidate() on the same
dentry in parallel.  They end up fighting each other - any
dentry picked for removal by one will be skipped by the rest
and we'll go for the next iteration through the entire
subtree, even if everything is being skipped.  Morevoer, we
immediately go back to scanning the subtree.  The only thing
we really need is to dissolve all mounts in the subtree and
as soon as we've nothing left to do, we can just unhash the
dentry and bugger off.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-15 12:07:04 +09:00
Waiman Long
110bb8279d fs/dcache: Fix incorrect nr_dentry_unused accounting in shrink_dcache_sb()
commit 1dbd449c99 upstream.

The nr_dentry_unused per-cpu counter tracks dentries in both the LRU
lists and the shrink lists where the DCACHE_LRU_LIST bit is set.

The shrink_dcache_sb() function moves dentries from the LRU list to a
shrink list and subtracts the dentry count from nr_dentry_unused.  This
is incorrect as the nr_dentry_unused count will also be decremented in
shrink_dentry_list() via d_shrink_del().

To fix this double decrement, the decrement in the shrink_dcache_sb()
function is taken out.

Fixes: 4e717f5c10 ("list_lru: remove special case function list_lru_dispose_all."
Cc: stable@kernel.org
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-15 11:16:27 +09:00
Tetsuo Handa
7084c3296f fs/dcache.c: fix kmemcheck splat at take_dentry_name_snapshot()
[ Upstream commit 6cd00a01f0 ]

Since only dentry->d_name.len + 1 bytes out of DNAME_INLINE_LEN bytes
are initialized at __d_alloc(), we can't copy the whole size
unconditionally.

 WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff8fa27465ac50)
 636f6e66696766732e746d70000000000010000000000000020000000188ffff
  i i i i i i i i i i i i i u u u u u u u u u u i i i i i u u u u
                                  ^
 RIP: 0010:take_dentry_name_snapshot+0x28/0x50
 RSP: 0018:ffffa83000f5bdf8 EFLAGS: 00010246
 RAX: 0000000000000020 RBX: ffff8fa274b20550 RCX: 0000000000000002
 RDX: ffffa83000f5be40 RSI: ffff8fa27465ac50 RDI: ffffa83000f5be60
 RBP: ffffa83000f5bdf8 R08: ffffa83000f5be48 R09: 0000000000000001
 R10: ffff8fa27465ac00 R11: ffff8fa27465acc0 R12: ffff8fa27465ac00
 R13: ffff8fa27465acc0 R14: 0000000000000000 R15: 0000000000000000
 FS:  00007f79737ac8c0(0000) GS:ffffffff8fc30000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffff8fa274c0b000 CR3: 0000000134aa7002 CR4: 00000000000606f0
  take_dentry_name_snapshot+0x28/0x50
  vfs_rename+0x128/0x870
  SyS_rename+0x3b2/0x3d0
  entry_SYSCALL_64_fastpath+0x1a/0xa4
  0xffffffffffffffff

Link: http://lkml.kernel.org/r/201709131912.GBG39012.QMJLOVFSFFOOtH@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-12 17:26:00 +09:00
Al Viro
fd9e38e2ba make sure that __dentry_kill() always invalidates d_seq, unhashed or not
commit 4c0d7cd5c8 upstream.

RCU pathwalk relies upon the assumption that anything that changes
->d_inode of a dentry will invalidate its ->d_seq.  That's almost
true - the one exception is that the final dput() of already unhashed
dentry does *not* touch ->d_seq at all.  Unhashing does, though,
so for anything we'd found by RCU dcache lookup we are fine.
Unfortunately, we can *start* with an unhashed dentry or jump into
it.

We could try and be careful in the (few) places where that could
happen.  Or we could just make the final dput() invalidate the damn
thing, unhashed or not.  The latter is much simpler and easier to
backport, so let's do it that way.

Reported-by: "Dae R. Jeong" <threeearcat@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-12 16:46:53 +09:00
Al Viro
29e7130c1d root dentries need RCU-delayed freeing
commit 90bad5e05b upstream.

Since mountpoint crossing can happen without leaving lazy mode,
root dentries do need the same protection against having their
memory freed without RCU delay as everything else in the tree.

It's partially hidden by RCU delay between detaching from the
mount tree and dropping the vfsmount reference, but the starting
point of pathwalk can be on an already detached mount, in which
case umount-caused RCU delay has already passed by the time the
lazy pathwalk grabs rcu_read_lock().  If the starting point
happens to be at the root of that vfsmount *and* that vfsmount
covers the entire filesystem, we get trouble.

Fixes: 48a066e72d ("RCU'd vsfmounts")
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-12 16:46:50 +09:00
Greg Kroah-Hartman
9797dcb8c7 Merge 4.9.104 into android-4.9
Changes in 4.9.104
	MIPS: c-r4k: Fix data corruption related to cache coherence
	MIPS: ptrace: Expose FIR register through FP regset
	MIPS: Fix ptrace(2) PTRACE_PEEKUSR and PTRACE_POKEUSR accesses to o32 FGRs
	KVM: Fix spelling mistake: "cop_unsuable" -> "cop_unusable"
	affs_lookup(): close a race with affs_remove_link()
	aio: fix io_destroy(2) vs. lookup_ioctx() race
	ALSA: timer: Fix pause event notification
	do d_instantiate/unlock_new_inode combinations safely
	mmc: sdhci-iproc: remove hard coded mmc cap 1.8v
	mmc: sdhci-iproc: fix 32bit writes for TRANSFER_MODE register
	libata: Blacklist some Sandisk SSDs for NCQ
	libata: blacklist Micron 500IT SSD with MU01 firmware
	xen-swiotlb: fix the check condition for xen_swiotlb_free_coherent
	drm/vmwgfx: Fix 32-bit VMW_PORT_HB_[IN|OUT] macros
	IB/hfi1: Use after free race condition in send context error path
	Revert "ipc/shm: Fix shmat mmap nil-page protection"
	ipc/shm: fix shmat() nil address after round-down when remapping
	kasan: fix memory hotplug during boot
	kernel/sys.c: fix potential Spectre v1 issue
	kernel/signal.c: avoid undefined behaviour in kill_something_info
	KVM/VMX: Expose SSBD properly to guests
	KVM: s390: vsie: fix < 8k check for the itdba
	KVM: x86: Update cpuid properly when CR4.OSXAVE or CR4.PKE is changed
	kvm: x86: IA32_ARCH_CAPABILITIES is always supported
	firewire-ohci: work around oversized DMA reads on JMicron controllers
	x86/tsc: Allow TSC calibration without PIT
	NFSv4: always set NFS_LOCK_LOST when a lock is lost.
	ALSA: hda - Use IS_REACHABLE() for dependency on input
	kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl
	netfilter: ipv6: nf_defrag: Pass on packets to stack per RFC2460
	tracing/hrtimer: Fix tracing bugs by taking all clock bases and modes into account
	PCI: Add function 1 DMA alias quirk for Marvell 9128
	Input: psmouse - fix Synaptics detection when protocol is disabled
	i40iw: Zero-out consumer key on allocate stag for FMR
	tools lib traceevent: Simplify pointer print logic and fix %pF
	perf callchain: Fix attr.sample_max_stack setting
	tools lib traceevent: Fix get_field_str() for dynamic strings
	perf record: Fix failed memory allocation for get_cpuid_str
	iommu/vt-d: Use domain instead of cache fetching
	dm thin: fix documentation relative to low water mark threshold
	net: stmmac: dwmac-meson8b: fix setting the RGMII TX clock on Meson8b
	net: stmmac: dwmac-meson8b: propagate rate changes to the parent clock
	nfs: Do not convert nfs_idmap_cache_timeout to jiffies
	watchdog: sp5100_tco: Fix watchdog disable bit
	kconfig: Don't leak main menus during parsing
	kconfig: Fix automatic menu creation mem leak
	kconfig: Fix expr_free() E_NOT leak
	mac80211_hwsim: fix possible memory leak in hwsim_new_radio_nl()
	ipmi/powernv: Fix error return code in ipmi_powernv_probe()
	Btrfs: set plug for fsync
	btrfs: Fix out of bounds access in btrfs_search_slot
	Btrfs: fix scrub to repair raid6 corruption
	btrfs: fail mount when sb flag is not in BTRFS_SUPER_FLAG_SUPP
	HID: roccat: prevent an out of bounds read in kovaplus_profile_activated()
	fm10k: fix "failed to kill vid" message for VF
	device property: Define type of PROPERTY_ENRTY_*() macros
	jffs2: Fix use-after-free bug in jffs2_iget()'s error handling path
	powerpc/numa: Use ibm,max-associativity-domains to discover possible nodes
	powerpc/numa: Ensure nodes initialized for hotplug
	RDMA/mlx5: Avoid memory leak in case of XRCD dealloc failure
	ntb_transport: Fix bug with max_mw_size parameter
	gianfar: prevent integer wrapping in the rx handler
	tcp_nv: fix potential integer overflow in tcpnv_acked
	kvm: Map PFN-type memory regions as writable (if possible)
	ocfs2: return -EROFS to mount.ocfs2 if inode block is invalid
	ocfs2/acl: use 'ip_xattr_sem' to protect getting extended attribute
	ocfs2: return error when we attempt to access a dirty bh in jbd2
	mm/mempolicy: fix the check of nodemask from user
	mm/mempolicy: add nodes_empty check in SYSC_migrate_pages
	asm-generic: provide generic_pmdp_establish()
	sparc64: update pmdp_invalidate() to return old pmd value
	mm: thp: use down_read_trylock() in khugepaged to avoid long block
	mm: pin address_space before dereferencing it while isolating an LRU page
	mm/fadvise: discard partial page if endbyte is also EOF
	openvswitch: Remove padding from packet before L3+ conntrack processing
	IB/ipoib: Fix for potential no-carrier state
	drm/nouveau/pmu/fuc: don't use movw directly anymore
	netfilter: ipv6: nf_defrag: Kill frag queue on RFC2460 failure
	x86/power: Fix swsusp_arch_resume prototype
	firmware: dmi_scan: Fix handling of empty DMI strings
	ACPI: processor_perflib: Do not send _PPC change notification if not ready
	ACPI / scan: Use acpi_bus_get_status() to initialize ACPI_TYPE_DEVICE devs
	bpf: fix selftests/bpf test_kmod.sh failure when CONFIG_BPF_JIT_ALWAYS_ON=y
	MIPS: generic: Fix machine compatible matching
	MIPS: TXx9: use IS_BUILTIN() for CONFIG_LEDS_CLASS
	xen-netfront: Fix race between device setup and open
	xen/grant-table: Use put_page instead of free_page
	RDS: IB: Fix null pointer issue
	arm64: spinlock: Fix theoretical trylock() A-B-A with LSE atomics
	proc: fix /proc/*/map_files lookup
	cifs: silence compiler warnings showing up with gcc-8.0.0
	bcache: properly set task state in bch_writeback_thread()
	bcache: fix for allocator and register thread race
	bcache: fix for data collapse after re-attaching an attached device
	bcache: return attach error when no cache set exist
	tools/libbpf: handle issues with bpf ELF objects containing .eh_frames
	bpf: fix rlimit in reuseport net selftest
	vfs/proc/kcore, x86/mm/kcore: Fix SMAP fault when dumping vsyscall user page
	locking/qspinlock: Ensure node->count is updated before initialising node
	irqchip/gic-v3: Ignore disabled ITS nodes
	cpumask: Make for_each_cpu_wrap() available on UP as well
	irqchip/gic-v3: Change pr_debug message to pr_devel
	ARC: Fix malformed ARC_EMUL_UNALIGNED default
	ptr_ring: prevent integer overflow when calculating size
	libata: Fix compile warning with ATA_DEBUG enabled
	selftests: pstore: Adding config fragment CONFIG_PSTORE_RAM=m
	selftests: memfd: add config fragment for fuse
	ARM: OMAP2+: timer: fix a kmemleak caused in omap_get_timer_dt
	ARM: OMAP3: Fix prm wake interrupt for resume
	ARM: OMAP1: clock: Fix debugfs_create_*() usage
	ibmvnic: Free RX socket buffer in case of adapter error
	iwlwifi: mvm: fix security bug in PN checking
	iwlwifi: mvm: always init rs with 20mhz bandwidth rates
	NFC: llcp: Limit size of SDP URI
	rxrpc: Work around usercopy check
	mac80211: round IEEE80211_TX_STATUS_HEADROOM up to multiple of 4
	mac80211: fix a possible leak of station stats
	mac80211: fix calling sleeping function in atomic context
	mac80211: Do not disconnect on invalid operating class
	md raid10: fix NULL deference in handle_write_completed()
	drm/exynos: g2d: use monotonic timestamps
	drm/exynos: fix comparison to bitshift when dealing with a mask
	locking/xchg/alpha: Add unconditional memory barrier to cmpxchg()
	md: raid5: avoid string overflow warning
	kernel/relay.c: limit kmalloc size to KMALLOC_MAX_SIZE
	powerpc/bpf/jit: Fix 32-bit JIT for seccomp_data access
	s390/cio: fix ccw_device_start_timeout API
	s390/cio: fix return code after missing interrupt
	s390/cio: clear timer when terminating driver I/O
	PKCS#7: fix direct verification of SignerInfo signature
	ARM: OMAP: Fix dmtimer init for omap1
	smsc75xx: fix smsc75xx_set_features()
	regulatory: add NUL to request alpha2
	integrity/security: fix digsig.c build error with header file
	locking/xchg/alpha: Fix xchg() and cmpxchg() memory ordering bugs
	x86/topology: Update the 'cpu cores' field in /proc/cpuinfo correctly across CPU hotplug operations
	mac80211: drop frames with unexpected DS bits from fast-rx to slow path
	arm64: fix unwind_frame() for filtered out fn for function graph tracing
	macvlan: fix use-after-free in macvlan_common_newlink()
	kvm: fix warning for CONFIG_HAVE_KVM_EVENTFD builds
	fs: dcache: Avoid livelock between d_alloc_parallel and __d_add
	fs: dcache: Use READ_ONCE when accessing i_dir_seq
	md: fix a potential deadlock of raid5/raid10 reshape
	md/raid1: fix NULL pointer dereference
	batman-adv: fix packet checksum in receive path
	batman-adv: invalidate checksum on fragment reassembly
	netfilter: ebtables: convert BUG_ONs to WARN_ONs
	batman-adv: Ignore invalid batadv_iv_gw during netlink send
	batman-adv: Ignore invalid batadv_v_gw during netlink send
	batman-adv: Fix netlink dumping of BLA claims
	batman-adv: Fix netlink dumping of BLA backbones
	nvme-pci: Fix nvme queue cleanup if IRQ setup fails
	clocksource/drivers/fsl_ftm_timer: Fix error return checking
	ceph: fix dentry leak when failing to init debugfs
	ARM: orion5x: Revert commit 4904dbda41.
	qrtr: add MODULE_ALIAS macro to smd
	r8152: fix tx packets accounting
	virtio-gpu: fix ioctl and expose the fixed status to userspace.
	dmaengine: rcar-dmac: fix max_chunk_size for R-Car Gen3
	bcache: fix kcrashes with fio in RAID5 backend dev
	ip6_tunnel: fix IFLA_MTU ignored on NEWLINK
	sit: fix IFLA_MTU ignored on NEWLINK
	ARM: dts: NSP: Fix amount of RAM on BCM958625HR
	powerpc/boot: Fix random libfdt related build errors
	gianfar: Fix Rx byte accounting for ndev stats
	net/tcp/illinois: replace broken algorithm reference link
	nvmet: fix PSDT field check in command format
	xen/pirq: fix error path cleanup when binding MSIs
	drm/sun4i: Fix dclk_set_phase
	Btrfs: send, fix issuing write op when processing hole in no data mode
	selftests/powerpc: Skip the subpage_prot tests if the syscall is unavailable
	KVM: PPC: Book3S HV: Fix VRMA initialization with 2MB or 1GB memory backing
	iwlwifi: mvm: fix TX of CCMP 256
	watchdog: f71808e_wdt: Fix magic close handling
	watchdog: sbsa: use 32-bit read for WCV
	batman-adv: Fix multicast packet loss with a single WANT_ALL_IPV4/6 flag
	e1000e: Fix check_for_link return value with autoneg off
	e1000e: allocate ring descriptors with dma_zalloc_coherent
	ia64/err-inject: Use get_user_pages_fast()
	RDMA/qedr: Fix kernel panic when running fio over NFSoRDMA
	RDMA/qedr: Fix iWARP write and send with immediate
	IB/mlx4: Fix corruption of RoCEv2 IPv4 GIDs
	IB/mlx4: Include GID type when deleting GIDs from HW table under RoCE
	IB/mlx5: Fix an error code in __mlx5_ib_modify_qp()
	fbdev: Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in sbusfb_ioctl_helper().
	fsl/fman: avoid sleeping in atomic context while adding an address
	net: qcom/emac: Use proper free methods during TX
	net: smsc911x: Fix unload crash when link is up
	IB/core: Fix possible crash to access NULL netdev
	xen: xenbus: use put_device() instead of kfree()
	arm64: Relax ARM_SMCCC_ARCH_WORKAROUND_1 discovery
	dmaengine: mv_xor_v2: Fix clock resource by adding a register clock
	netfilter: ebtables: fix erroneous reject of last rule
	bnxt_en: Check valid VNIC ID in bnxt_hwrm_vnic_set_tpa().
	workqueue: use put_device() instead of kfree()
	ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmtu
	sunvnet: does not support GSO for sctp
	drm/imx: move arming of the vblank event to atomic_flush
	net: Fix vlan untag for bridge and vlan_dev with reorder_hdr off
	batman-adv: fix header size check in batadv_dbg_arp()
	batman-adv: Fix skbuff rcsum on packet reroute
	vti4: Don't count header length twice on tunnel setup
	vti4: Don't override MTU passed on link creation via IFLA_MTU
	perf/cgroup: Fix child event counting bug
	brcmfmac: Fix check for ISO3166 code
	kbuild: make scripts/adjust_autoksyms.sh robust against timestamp races
	RDMA/ucma: Correct option size check using optlen
	RDMA/qedr: fix QP's ack timeout configuration
	RDMA/qedr: Fix rc initialization on CNQ allocation failure
	mm/mempolicy.c: avoid use uninitialized preferred_node
	mm, thp: do not cause memcg oom for thp
	selftests: ftrace: Add probe event argument syntax testcase
	selftests: ftrace: Add a testcase for string type with kprobe_event
	selftests: ftrace: Add a testcase for probepoint
	batman-adv: fix multicast-via-unicast transmission with AP isolation
	batman-adv: fix packet loss for broadcasted DHCP packets to a server
	ARM: 8748/1: mm: Define vdso_start, vdso_end as array
	net: qmi_wwan: add BroadMobi BM806U 2020:2033
	perf/x86/intel: Fix linear IP of PEBS real_ip on Haswell and later CPUs
	llc: properly handle dev_queue_xmit() return value
	builddeb: Fix header package regarding dtc source links
	mm/kmemleak.c: wait for scan completion before disabling free
	net: Fix untag for vlan packets without ethernet header
	net: mvneta: fix enable of all initialized RXQs
	sh: fix debug trap failure to process signals before return to user
	nvme: don't send keep-alives to the discovery controller
	x86/pgtable: Don't set huge PUD/PMD on non-leaf entries
	x86/mm: Do not forbid _PAGE_RW before init for __ro_after_init
	fs/proc/proc_sysctl.c: fix potential page fault while unregistering sysctl table
	swap: divide-by-zero when zero length swap file on ssd
	sr: get/drop reference to device in revalidate and check_events
	Force log to disk before reading the AGF during a fstrim
	cpufreq: CPPC: Initialize shared perf capabilities of CPUs
	dp83640: Ensure against premature access to PHY registers after reset
	mm/ksm: fix interaction with THP
	mm: fix races between address_space dereference and free in page_evicatable
	Btrfs: bail out on error during replay_dir_deletes
	Btrfs: fix NULL pointer dereference in log_dir_items
	btrfs: Fix possible softlock on single core machines
	ocfs2/dlm: don't handle migrate lockres if already in shutdown
	sched/rt: Fix rq->clock_update_flags < RQCF_ACT_SKIP warning
	KVM: VMX: raise internal error for exception during invalid protected mode state
	fscache: Fix hanging wait on page discarded by writeback
	sparc64: Make atomic_xchg() an inline function rather than a macro.
	net: bgmac: Fix endian access in bgmac_dma_tx_ring_free()
	btrfs: tests/qgroup: Fix wrong tree backref level
	Btrfs: fix copy_items() return value when logging an inode
	btrfs: fix lockdep splat in btrfs_alloc_subvolume_writers
	rxrpc: Fix Tx ring annotation after initial Tx failure
	rxrpc: Don't treat call aborts as conn aborts
	xen/acpi: off by one in read_acpi_id()
	drivers: macintosh: rack-meter: really fix bogus memsets
	ACPI: acpi_pad: Fix memory leak in power saving threads
	powerpc/mpic: Check if cpu_possible() in mpic_physmask()
	m68k: set dma and coherent masks for platform FEC ethernets
	parisc/pci: Switch LBA PCI bus from Hard Fail to Soft Fail mode
	hwmon: (nct6775) Fix writing pwmX_mode
	powerpc/perf: Prevent kernel address leak to userspace via BHRB buffer
	powerpc/perf: Fix kernel address leak via sampling registers
	tools/thermal: tmon: fix for segfault
	selftests: Print the test we're running to /dev/kmsg
	net/mlx5: Protect from command bit overflow
	ath10k: Fix kernel panic while using worker (ath10k_sta_rc_update_wk)
	cxgb4: Setup FW queues before registering netdev
	ima: Fallback to the builtin hash algorithm
	virtio-net: Fix operstate for virtio when no VIRTIO_NET_F_STATUS
	arm: dts: socfpga: fix GIC PPI warning
	cpufreq: cppc_cpufreq: Fix cppc_cpufreq_init() failure path
	zorro: Set up z->dev.dma_mask for the DMA API
	bcache: quit dc->writeback_thread when BCACHE_DEV_DETACHING is set
	ACPICA: Events: add a return on failure from acpi_hw_register_read
	ACPICA: acpi: acpica: fix acpi operand cache leak in nseval.c
	cxgb4: Fix queue free path of ULD drivers
	i2c: mv64xxx: Apply errata delay only in standard mode
	KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use
	perf top: Fix top.call-graph config option reading
	perf stat: Fix core dump when flag T is used
	IB/core: Honor port_num while resolving GID for IB link layer
	regulator: gpio: Fix some error handling paths in 'gpio_regulator_probe()'
	spi: bcm-qspi: fIX some error handling paths
	MIPS: ath79: Fix AR724X_PLL_REG_PCIE_CONFIG offset
	PCI: Restore config space on runtime resume despite being unbound
	ipmi_ssif: Fix kernel panic at msg_done_handler
	powerpc: Add missing prototype for arch_irq_work_raise()
	f2fs: fix to check extent cache in f2fs_drop_extent_tree
	perf/core: Fix perf_output_read_group()
	drm/panel: simple: Fix the bus format for the Ontat panel
	hwmon: (pmbus/max8688) Accept negative page register values
	hwmon: (pmbus/adm1275) Accept negative page register values
	perf/x86/intel: Properly save/restore the PMU state in the NMI handler
	cdrom: do not call check_disk_change() inside cdrom_open()
	perf/x86/intel: Fix large period handling on Broadwell CPUs
	perf/x86/intel: Fix event update for auto-reload
	arm64: dts: qcom: Fix SPI5 config on MSM8996
	soc: qcom: wcnss_ctrl: Fix increment in NV upload
	gfs2: Fix fallocate chunk size
	x86/devicetree: Initialize device tree before using it
	x86/devicetree: Fix device IRQ settings in DT
	ALSA: vmaster: Propagate slave error
	dmaengine: pl330: fix a race condition in case of threaded irqs
	dmaengine: rcar-dmac: Check the done lists in rcar_dmac_chan_get_residue()
	enic: enable rq before updating rq descriptors
	hwrng: stm32 - add reset during probe
	dmaengine: qcom: bam_dma: get num-channels and num-ees from dt
	net: stmmac: ensure that the device has released ownership before reading data
	net: stmmac: ensure that the MSS desc is the last desc to set the own bit
	cpufreq: Reorder cpufreq_online() error code path
	PCI: Add function 1 DMA alias quirk for Marvell 88SE9220
	udf: Provide saner default for invalid uid / gid
	ARM: dts: bcm283x: Fix probing of bcm2835-i2s
	audit: return on memory error to avoid null pointer dereference
	rcu: Call touch_nmi_watchdog() while printing stall warnings
	pinctrl: sh-pfc: r8a7796: Fix MOD_SEL register pin assignment for SSI pins group
	MIPS: Octeon: Fix logging messages with spurious periods after newlines
	drm/rockchip: Respect page offset for PRIME mmap calls
	x86/apic: Set up through-local-APIC mode on the boot CPU if 'noapic' specified
	perf tests: Use arch__compare_symbol_names to compare symbols
	perf report: Fix memory corruption in --branch-history mode --branch-history
	selftests/net: fixes psock_fanout eBPF test case
	netlabel: If PF_INET6, check sk_buff ip header version
	regmap: Correct comparison in regmap_cached
	ARM: dts: imx7d: cl-som-imx7: fix pinctrl_enet
	ARM: dts: porter: Fix HDMI output routing
	regulator: of: Add a missing 'of_node_put()' in an error handling path of 'of_regulator_match()'
	pinctrl: msm: Use dynamic GPIO numbering
	kdb: make "mdr" command repeat
	Linux 4.9.104

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-05-30 13:19:56 +02:00
Will Deacon
527ed41ff2 fs: dcache: Use READ_ONCE when accessing i_dir_seq
[ Upstream commit 8cc07c808c ]

i_dir_seq is subject to concurrent modification by a cmpxchg or
store-release operation, so ensure that the relaxed access in
d_alloc_parallel uses READ_ONCE.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30 07:50:30 +02:00
Will Deacon
bcefedb87c fs: dcache: Avoid livelock between d_alloc_parallel and __d_add
[ Upstream commit 015555fd4d ]

If d_alloc_parallel runs concurrently with __d_add, it is possible for
d_alloc_parallel to continuously retry whilst i_dir_seq has been
incremented to an odd value by __d_add:

CPU0:
__d_add
	n = start_dir_add(dir);
		cmpxchg(&dir->i_dir_seq, n, n + 1) == n

CPU1:
d_alloc_parallel
retry:
	seq = smp_load_acquire(&parent->d_inode->i_dir_seq) & ~1;
	hlist_bl_lock(b);
		bit_spin_lock(0, (unsigned long *)b); // Always succeeds

CPU0:
	__d_lookup_done(dentry)
		hlist_bl_lock
			bit_spin_lock(0, (unsigned long *)b); // Never succeeds

CPU1:
	if (unlikely(parent->d_inode->i_dir_seq != seq)) {
		hlist_bl_unlock(b);
		goto retry;
	}

Since the simple bit_spin_lock used to implement hlist_bl_lock does not
provide any fairness guarantees, then CPU1 can starve CPU0 of the lock
and prevent it from reaching end_dir_add(dir), therefore CPU1 cannot
exit its retry loop because the sequence number always has the bottom
bit set.

This patch resolves the livelock by not taking hlist_bl_lock in
d_alloc_parallel if the sequence counter is odd, since any subsequent
masked comparison with i_dir_seq will fail anyway.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Naresh Madhusudana <naresh.madhusudana@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30 07:50:30 +02:00
Al Viro
2d2d3f1ee7 do d_instantiate/unlock_new_inode combinations safely
commit 1e2e547a93 upstream.

For anything NFS-exported we do _not_ want to unlock new inode
before it has grown an alias; original set of fixes got the
ordering right, but missed the nasty complication in case of
lockdep being enabled - unlock_new_inode() does
	lockdep_annotate_inode_mutex_key(inode)
which can only be done before anyone gets a chance to touch
->i_mutex.  Unfortunately, flipping the order and doing
unlock_new_inode() before d_instantiate() opens a window when
mkdir can race with open-by-fhandle on a guessed fhandle, leading
to multiple aliases for a directory inode and all the breakage
that follows from that.

	Correct solution: a new primitive (d_instantiate_new())
combining these two in the right order - lockdep annotate, then
d_instantiate(), then the rest of unlock_new_inode().  All
combinations of d_instantiate() with unlock_new_inode() should
be converted to that.

Cc: stable@kernel.org	# 2.6.29 and later
Tested-by: Mike Marshall <hubcap@omnibond.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30 07:50:16 +02:00
Greg Kroah-Hartman
8683408f8e Merge 4.9.94 into android-4.9
Changes in 4.9.94
	qed: Fix overriding of supported autoneg value.
	cfg80211: make RATE_INFO_BW_20 the default
	md/raid5: make use of spin_lock_irq over local_irq_disable + spin_lock
	rtc: snvs: fix an incorrect check of return value
	x86/asm: Don't use RBP as a temporary register in csum_partial_copy_generic()
	x86/mm/kaslr: Use the _ASM_MUL macro for multiplication to work around Clang incompatibility
	ovl: persistent inode numbers for upper hardlinks
	NFSv4.1: RECLAIM_COMPLETE must handle NFS4ERR_CONN_NOT_BOUND_TO_SESSION
	x86/boot: Declare error() as noreturn
	IB/srpt: Fix abort handling
	IB/srpt: Avoid that aborting a command triggers a kernel warning
	af_key: Fix slab-out-of-bounds in pfkey_compile_policy.
	mac80211: bail out from prep_connection() if a reconfig is ongoing
	bna: Avoid reading past end of buffer
	qlge: Avoid reading past end of buffer
	ubi: fastmap: Fix slab corruption
	ipmi_ssif: unlock on allocation failure
	net: cdc_ncm: Fix TX zero padding
	net: ethernet: ti: cpsw: adjust cpsw fifos depth for fullduplex flow control
	lockd: fix lockd shutdown race
	drivers/misc/vmw_vmci/vmci_queue_pair.c: fix a couple integer overflow tests
	pidns: disable pid allocation if pid_ns_prepare_proc() is failed in alloc_pid()
	s390: move _text symbol to address higher than zero
	net/mlx4_en: Avoid adding steering rules with invalid ring
	qed: Correct doorbell configuration for !4Kb pages
	NFSv4.1: Work around a Linux server bug...
	CIFS: silence lockdep splat in cifs_relock_file()
	perf/callchain: Force USER_DS when invoking perf_callchain_user()
	blk-mq: NVMe 512B/4K+T10 DIF/DIX format returns I/O error on dd with split op
	net: qca_spi: Fix alignment issues in rx path
	netxen_nic: set rcode to the return status from the call to netxen_issue_cmd
	mdio: mux: Correct mdio_mux_init error path issues
	Input: elan_i2c - check if device is there before really probing
	Input: elantech - force relative mode on a certain module
	KVM: PPC: Book3S PR: Check copy_to/from_user return values
	irqchip/mbigen: Fix the clear register offset calculation
	vmxnet3: ensure that adapter is in proper state during force_close
	mm, vmstat: Remove spurious WARN() during zoneinfo print
	SMB2: Fix share type handling
	bus: brcmstb_gisb: Use register offsets with writes too
	bus: brcmstb_gisb: correct support for 64-bit address output
	PowerCap: Fix an error code in powercap_register_zone()
	iio: pressure: zpa2326: report interrupted case as failure
	ARM: dts: imx53-qsrb: Pulldown PMIC IRQ pin
	staging: wlan-ng: prism2mgmt.c: fixed a double endian conversion before calling hfa384x_drvr_setconfig16, also fixes relative sparse warning
	clk: renesas: rcar-gen2: Fix PLL0 on R-Car V2H and E2
	x86/tsc: Provide 'tsc=unstable' boot parameter
	powerpc/modules: If mprofile-kernel is enabled add it to vermagic
	ARM: dts: imx6qdl-wandboard: Fix audio channel swap
	i2c: mux: reg: put away the parent i2c adapter on probe failure
	arm64: perf: Ignore exclude_hv when kernel is running in HYP
	mdio: mux: fix device_node_continue.cocci warnings
	ipv6: avoid dad-failures for addresses with NODAD
	async_tx: Fix DMA_PREP_FENCE usage in do_async_gen_syndrome()
	KVM: arm: Restore banked registers and physical timer access on hyp_panic()
	KVM: arm64: Restore host physical timer access on hyp_panic()
	usb: dwc3: keystone: check return value
	btrfs: fix incorrect error return ret being passed to mapping_set_error
	ata: libahci: properly propagate return value of platform_get_irq()
	ipmr: vrf: Find VIFs using the actual device
	uio: fix incorrect memory leak cleanup
	neighbour: update neigh timestamps iff update is effective
	arp: honour gratuitous ARP _replies_
	ARM: dts: rockchip: fix rk322x i2s1 pinctrl error
	usb: chipidea: properly handle host or gadget initialization failure
	pxa_camera: fix module remove codepath for v4l2 clock
	USB: ene_usb6250: fix first command execution
	net: x25: fix one potential use-after-free issue
	USB: ene_usb6250: fix SCSI residue overwriting
	serial: 8250: omap: Disable DMA for console UART
	serial: sh-sci: Fix race condition causing garbage during shutdown
	net/wan/fsl_ucc_hdlc: fix unitialized variable warnings
	net/wan/fsl_ucc_hdlc: fix incorrect memory allocation
	fsl/qe: add bit description for SYNL register for GUMR
	sh_eth: Use platform device for printing before register_netdev()
	mlxsw: spectrum: Avoid possible NULL pointer dereference
	scsi: csiostor: fix use after free in csio_hw_use_fwconfig()
	powerpc/mm: Fix virt_addr_valid() etc. on 64-bit hash
	ath5k: fix memory leak on buf on failed eeprom read
	selftests/powerpc: Fix TM resched DSCR test with some compilers
	xfrm: fix state migration copy replay sequence numbers
	ASoC: simple-card: fix mic jack initialization
	iio: hi8435: avoid garbage event at first enable
	iio: hi8435: cleanup reset gpio
	iio: light: rpr0521 poweroff for probe fails
	ext4: handle the rest of ext4_mb_load_buddy() ENOMEM errors
	md-cluster: fix potential lock issue in add_new_disk
	ARM: davinci: da8xx: Create DSP device only when assigned memory
	ray_cs: Avoid reading past end of buffer
	net/wan/fsl_ucc_hdlc: fix muram allocation error
	leds: pca955x: Correct I2C Functionality
	perf/core: Fix error handling in perf_event_alloc()
	sched/numa: Use down_read_trylock() for the mmap_sem
	gpio: crystalcove: Do not write regular gpio registers for virtual GPIOs
	net/mlx5: Tolerate irq_set_affinity_hint() failures
	selinux: do not check open permission on sockets
	block: fix an error code in add_partition()
	mlx5: fix bug reading rss_hash_type from CQE
	net: ieee802154: fix net_device reference release too early
	libceph: NULL deref on crush_decode() error path
	perf report: Fix off-by-one for non-activation frames
	netfilter: ctnetlink: fix incorrect nf_ct_put during hash resize
	pNFS/flexfiles: missing error code in ff_layout_alloc_lseg()
	ASoC: rsnd: SSI PIO adjust to 24bit mode
	scsi: bnx2fc: fix race condition in bnx2fc_get_host_stats()
	fix race in drivers/char/random.c:get_reg()
	ext4: fix off-by-one on max nr_pages in ext4_find_unwritten_pgoff()
	ARM64: PCI: Fix struct acpi_pci_root_ops allocation failure path
	tcp: better validation of received ack sequences
	net: move somaxconn init from sysctl code
	Input: elan_i2c - clear INT before resetting controller
	bonding: Don't update slave->link until ready to commit
	cpuhotplug: Link lock stacks for hotplug callbacks
	PCI/msi: fix the pci_alloc_irq_vectors_affinity stub
	KVM: X86: Fix preempt the preemption timer cancel
	KVM: nVMX: Fix handling of lmsw instruction
	net: llc: add lock_sock in llc_ui_bind to avoid a race condition
	drm/msm: Take the mutex before calling msm_gem_new_impl
	i40iw: Fix sequence number for the first partial FPDU
	i40iw: Correct Q1/XF object count equation
	ARM: dts: ls1021a: add "fsl,ls1021a-esdhc" compatible string to esdhc node
	thermal: power_allocator: fix one race condition issue for thermal_instances list
	perf probe: Add warning message if there is unexpected event name
	l2tp: fix missing print session offset info
	rds; Reset rs->rs_bound_addr in rds_add_bound() failure path
	ACPI / video: Default lcd_only to true on Win8-ready and newer machines
	net/mlx4_en: Change default QoS settings
	VFS: close race between getcwd() and d_move()
	PM / devfreq: Fix potential NULL pointer dereference in governor_store
	hwmon: (ina2xx) Make calibration register value fixed
	media: videobuf2-core: don't go out of the buffer range
	ASoC: Intel: Skylake: Disable clock gating during firmware and library download
	ASoC: Intel: cht_bsw_rt5645: Analog Mic support
	scsi: libiscsi: Allow sd_shutdown on bad transport
	scsi: mpt3sas: Proper handling of set/clear of "ATA command pending" flag.
	irqchip/gic-v3: Fix the driver probe() fail due to disabled GICC entry
	ACPI: EC: Fix debugfs_create_*() usage
	mac80211: Fix setting TX power on monitor interfaces
	vfb: fix video mode and line_length being set when loaded
	gpio: label descriptors using the device name
	IB/rdmavt: Allocate CQ memory on the correct node
	blk-mq: fix race between updating nr_hw_queues and switching io sched
	backlight: tdo24m: Fix the SPI CS between transfers
	pinctrl: baytrail: Enable glitch filter for GPIOs used as interrupts
	ASoC: Intel: sst: Fix the return value of 'sst_send_byte_stream_mrfld()'
	rt2x00: do not pause queue unconditionally on error path
	wl1251: check return from call to wl1251_acx_arp_ip_filter
	hdlcdrv: Fix divide by zero in hdlcdrv_ioctl
	x86/efi: Disable runtime services on kexec kernel if booted with efi=old_map
	netfilter: conntrack: don't call iter for non-confirmed conntracks
	HID: i2c: Call acpi_device_fix_up_power for ACPI-enumerated devices
	ovl: filter trusted xattr for non-admin
	powerpc/[booke|4xx]: Don't clobber TCR[WP] when setting TCR[DIE]
	dmaengine: imx-sdma: Handle return value of clk_prepare_enable
	backlight: Report error on failure
	arm64: futex: Fix undefined behaviour with FUTEX_OP_OPARG_SHIFT usage
	net/mlx5: avoid build warning for uniprocessor
	cxgb4: FW upgrade fixes
	cxgb4: Fix netdev_features flag
	rtc: m41t80: fix SQW dividers override when setting a date
	i40evf: fix merge error in older patch
	rtc: opal: Handle disabled TPO in opal_get_tpo_time()
	rtc: interface: Validate alarm-time before handling rollover
	SUNRPC: ensure correct error is reported by xs_tcp_setup_socket()
	net: freescale: fix potential null pointer dereference
	clk: at91: fix clk-generated parenting
	drm/sun4i: Ignore the generic connectors for components
	dt-bindings: display: sun4i: Add allwinner,tcon-channel property
	mtd: nand: gpmi: Fix gpmi_nand_init() error path
	mtd: nand: check ecc->total sanity in nand_scan_tail
	KVM: SVM: do not zero out segment attributes if segment is unusable or not present
	clk: scpi: fix return type of __scpi_dvfs_round_rate
	clk: Fix __set_clk_rates error print-string
	powerpc/spufs: Fix coredump of SPU contexts
	drm/amdkfd: NULL dereference involving create_process()
	ath10k: add BMI parameters to fix calibration from DT/pre-cal
	perf trace: Add mmap alias for s390
	qlcnic: Fix a sleep-in-atomic bug in qlcnic_82xx_hw_write_wx_2M and qlcnic_82xx_hw_read_wx_2M
	arm64: kernel: restrict /dev/mem read() calls to linear region
	mISDN: Fix a sleep-in-atomic bug
	net: phy: micrel: Restore led_mode and clk_sel on resume
	RDMA/iw_cxgb4: Avoid touch after free error in ARP failure handlers
	RDMA/hfi1: fix array termination by appending NULL to attr array
	drm/omap: fix tiled buffer stride calculations
	powerpc/8xx: fix mpc8xx_get_irq() return on no irq
	cxgb4: fix incorrect cim_la output for T6
	Fix serial console on SNI RM400 machines
	bio-integrity: Do not allocate integrity context for bio w/o data
	ip6_tunnel: fix traffic class routing for tunnels
	skbuff: return -EMSGSIZE in skb_to_sgvec to prevent overflow
	macsec: check return value of skb_to_sgvec always
	sit: reload iphdr in ipip6_rcv
	net/mlx4: Fix the check in attaching steering rules
	net/mlx4: Check if Granular QoS per VF has been enabled before updating QP qos_vport
	perf header: Set proper module name when build-id event found
	perf report: Ensure the perf DSO mapping matches what libdw sees
	iwlwifi: mvm: fix firmware debug restart recording
	watchdog: f71808e_wdt: Add F71868 support
	iwlwifi: mvm: Fix command queue number on d0i3 flow
	iwlwifi: tt: move ucode_loaded check under mutex
	iwlwifi: pcie: only use d0i3 in suspend/resume if system_pm is set to d0i3
	iwlwifi: fix min API version for 7265D, 3168, 8000 and 8265
	tags: honor COMPILED_SOURCE with apart output directory
	ARM: dts: qcom: ipq4019: fix i2c_0 node
	e1000e: fix race condition around skb_tstamp_tx()
	igb: fix race condition with PTP_TX_IN_PROGRESS bits
	cxl: Unlock on error in probe
	cx25840: fix unchecked return values
	mceusb: sporadic RX truncation corruption fix
	net: phy: avoid genphy_aneg_done() for PHYs without clause 22 support
	ARM: imx: Add MXC_CPU_IMX6ULL and cpu_is_imx6ull
	nvme-pci: fix multiple ctrl removal scheduling
	nvme: fix hang in remove path
	KVM: nVMX: Update vmcs12->guest_linear_address on nested VM-exit
	e1000e: Undo e1000e_pm_freeze if __e1000_shutdown fails
	perf/core: Correct event creation with PERF_FORMAT_GROUP
	sched/deadline: Use the revised wakeup rule for suspending constrained dl tasks
	MIPS: mm: fixed mappings: correct initialisation
	MIPS: mm: adjust PKMAP location
	MIPS: kprobes: flush_insn_slot should flush only if probe initialised
	ARM: dts: armadillo800eva: Split LCD mux and gpio
	Fix loop device flush before configure v3
	net: emac: fix reset timeout with AR8035 phy
	perf tools: Decompress kernel module when reading DSO data
	perf tests: Decompress kernel module before objdump
	skbuff: only inherit relevant tx_flags
	xen: avoid type warning in xchg_xen_ulong
	X.509: Fix error code in x509_cert_parse()
	pinctrl: meson-gxbb: remove non-existing pin GPIOX_22
	coresight: Fix reference count for software sources
	coresight: tmc: Configure DMA mask appropriately
	stmmac: fix ptp header for GMAC3 hw timestamp
	geneve: add missing rx stats accounting
	crypto: omap-sham - buffer handling fixes for hashing later
	crypto: omap-sham - fix closing of hash with separate finalize call
	bnx2x: Allow vfs to disable txvlan offload
	sctp: fix recursive locking warning in sctp_do_peeloff
	net: fec: Add a fec_enet_clear_ethtool_stats() stub for CONFIG_M5272
	sparc64: ldc abort during vds iso boot
	iio: magnetometer: st_magn_spi: fix spi_device_id table
	net: ena: fix rare uncompleted admin command false alarm
	net: ena: fix race condition between submit and completion admin command
	net: ena: add missing return when ena_com_get_io_handlers() fails
	net: ena: add missing unmap bars on device removal
	net: ena: disable admin msix while working in polling mode
	clk: meson: meson8b: add compatibles for Meson8 and Meson8m2
	Bluetooth: Send HCI Set Event Mask Page 2 command only when needed
	cpuidle: dt: Add missing 'of_node_put()'
	ACPICA: OSL: Add support to exclude stdarg.h
	ACPICA: Events: Add runtime stub support for event APIs
	ACPICA: Disassembler: Abort on an invalid/unknown AML opcode
	s390/dasd: fix hanging safe offline
	vxlan: dont migrate permanent fdb entries during learn
	hsr: fix incorrect warning
	selftests: kselftest_harness: Fix compile warning
	drm/vc4: Fix resource leak in 'vc4_get_hang_state_ioctl()' in error handling path
	bcache: stop writeback thread after detaching
	bcache: segregate flash only volume write streams
	scsi: libsas: fix memory leak in sas_smp_get_phy_events()
	scsi: libsas: fix error when getting phy events
	scsi: libsas: initialize sas_phy status according to response of DISCOVER
	blk-mq: fix kernel oops in blk_mq_tag_idle()
	tty: n_gsm: Allow ADM response in addition to UA for control dlci
	EDAC, mv64x60: Fix an error handling path
	cxgb4vf: Fix SGE FL buffer initialization logic for 64K pages
	sdhci: Advertise 2.0v supply on SDIO host controller
	Input: goodix - disable IRQs while suspended
	mtd: mtd_oobtest: Handle bitflips during reads
	perf tools: Fix copyfile_offset update of output offset
	ipsec: check return value of skb_to_sgvec always
	rxrpc: check return value of skb_to_sgvec always
	virtio_net: check return value of skb_to_sgvec always
	virtio_net: check return value of skb_to_sgvec in one more location
	random: use lockless method of accessing and updating f->reg_idx
	clk: at91: fix clk-generated compilation
	arp: fix arp_filter on l3slave devices
	ipv6: the entire IPv6 header chain must fit the first fragment
	net: fix possible out-of-bound read in skb_network_protocol()
	net/ipv6: Fix route leaking between VRFs
	net/ipv6: Increment OUTxxx counters after netfilter hook
	netlink: make sure nladdr has correct size in netlink_connect()
	net/sched: fix NULL dereference in the error path of tcf_bpf_init()
	pptp: remove a buggy dst release in pptp_connect()
	r8169: fix setting driver_data after register_netdev
	sctp: do not leak kernel memory to user space
	sctp: sctp_sockaddr_af must check minimal addr length for AF_INET6
	sky2: Increase D3 delay to sky2 stops working after suspend
	vhost: correctly remove wait queue during poll failure
	vlan: also check phy_driver ts_info for vlan's real device
	bonding: fix the err path for dev hwaddr sync in bond_enslave
	bonding: move dev_mc_sync after master_upper_dev_link in bond_enslave
	bonding: process the err returned by dev_set_allmulti properly in bond_enslave
	net: fool proof dev_valid_name()
	ip_tunnel: better validate user provided tunnel names
	ipv6: sit: better validate user provided tunnel names
	ip6_gre: better validate user provided tunnel names
	ip6_tunnel: better validate user provided tunnel names
	vti6: better validate user provided tunnel names
	net/mlx5e: Sync netdev vxlan ports at open
	net/sched: fix NULL dereference in the error path of tunnel_key_init()
	net/sched: fix NULL dereference on the error path of tcf_skbmod_init()
	net/mlx4_en: Fix mixed PFC and Global pause user control requests
	vhost: validate log when IOTLB is enabled
	route: check sysctl_fib_multipath_use_neigh earlier than hash
	team: move dev_mc_sync after master_upper_dev_link in team_port_add
	vhost_net: add missing lock nesting notation
	net/mlx4_core: Fix memory leak while delete slave's resources
	strparser: Fix sign of err codes
	net sched actions: fix dumping which requires several messages to user space
	vrf: Fix use after free and double free in vrf_finish_output
	Revert "xhci: plat: Register shutdown for xhci_plat"
	Linux 4.9.94

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-04-14 15:40:56 +02:00
NeilBrown
3aa66ba53e VFS: close race between getcwd() and d_move()
[ Upstream commit 61647823aa ]

d_move() will call __d_drop() and then __d_rehash()
on the dentry being moved.  This creates a small window
when the dentry appears to be unhashed.  Many tests
of d_unhashed() are made under ->d_lock and so are safe
from racing with this window, but some aren't.
In particular, getcwd() calls d_unlinked() (which calls
d_unhashed()) without d_lock protection, so it can race.

This races has been seen in practice with lustre, which uses d_move() as
part of name lookup.  See:
   https://jira.hpdd.intel.com/browse/LU-9735
It could race with a regular rename(), and result in ENOENT instead
of either the 'before' or 'after' name.

The race can be demonstrated with a simple program which
has two threads, one renaming a directory back and forth
while another calls getcwd() within that directory: it should never
fail, but does.  See:
  https://patchwork.kernel.org/patch/9455345/

We could fix this race by taking d_lock and rechecking when
d_unhashed() reports true.  Alternately when can remove the window,
which is the approach this patch takes.

___d_drop() is introduce which does *not* clear d_hash.pprev
so the dentry still appears to be hashed.  __d_drop() calls
___d_drop(), then clears d_hash.pprev.
__d_move() now uses ___d_drop() and only clears d_hash.pprev
when not rehashing.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-13 19:48:09 +02:00
Greg Kroah-Hartman
960923fdc2 Merge 4.9.89 into android-4.9
Changes in 4.9.89
	blkcg: fix double free of new_blkg in blkcg_init_queue
	Input: tsc2007 - check for presence and power down tsc2007 during probe
	perf stat: Issue a HW watchdog disable hint
	staging: speakup: Replace BUG_ON() with WARN_ON().
	staging: wilc1000: add check for kmalloc allocation failure.
	HID: reject input outside logical range only if null state is set
	drm: qxl: Don't alloc fbdev if emulation is not supported
	ARM: dts: r8a7791: Remove unit-address and reg from integrated cache
	ARM: dts: r8a7792: Remove unit-address and reg from integrated cache
	ARM: dts: r8a7793: Remove unit-address and reg from integrated cache
	ARM: dts: r8a7794: Remove unit-address and reg from integrated cache
	arm64: dts: r8a7796: Remove unit-address and reg from integrated cache
	drm/sun4i: Fix up error path cleanup for master bind function
	drm/sun4i: Set drm_crtc.port to the underlying TCON's output port node
	ath10k: fix a warning during channel switch with multiple vaps
	drm/sun4i: Fix TCON clock and regmap initialization sequence
	PCI/MSI: Stop disabling MSI/MSI-X in pci_device_shutdown()
	selinux: check for address length in selinux_socket_bind()
	x86/mm: Make mmap(MAP_32BIT) work correctly
	perf sort: Fix segfault with basic block 'cycles' sort dimension
	x86/mce: Handle broadcasted MCE gracefully with kexec
	eventpoll.h: fix epoll event masks
	i40e: Acquire NVM lock before reads on all devices
	i40e: fix ethtool to get EEPROM data from X722 interface
	perf tools: Make perf_event__synthesize_mmap_events() scale
	ARM: brcmstb: Enable ZONE_DMA for non 64-bit capable peripherals
	drivers: net: xgene: Fix hardware checksum setting
	drivers: net: phy: xgene: Fix mdio write
	drivers: net: xgene: Fix wrong logical operation
	drivers: net: xgene: Fix Rx checksum validation logic
	drm: Defer disabling the vblank IRQ until the next interrupt (for instant-off)
	ath10k: disallow DFS simulation if DFS channel is not enabled
	ath10k: fix fetching channel during potential radar detection
	usb: misc: lvs: fix race condition in disconnect handling
	ARM: bcm2835: Enable missing CMA settings for VC4 driver
	net: ethernet: bgmac: Allow MAC address to be specified in DTB
	netem: apply correct delay when rate throttling
	x86/mce: Init some CPU features early
	omapfb: dss: Handle return errors in dss_init_ports()
	perf probe: Fix concat_probe_trace_events
	perf probe: Return errno when not hitting any event
	HID: clamp input to logical range if no null state
	net/8021q: create device with all possible features in wanted_features
	ARM: dts: Adjust moxart IRQ controller and flags
	qed: Always publish VF link from leading hwfn
	s390/topology: fix typo in early topology code
	zd1211rw: fix NULL-deref at probe
	batman-adv: handle race condition for claims between gateways
	of: fix of_device_get_modalias returned length when truncating buffers
	solo6x10: release vb2 buffers in solo_stop_streaming()
	x86/boot/32: Defer resyncing initial_page_table until per-cpu is set up
	scsi: fnic: Fix for "Number of Active IOs" in fnicstats becoming negative
	scsi: ipr: Fix missed EH wakeup
	media: i2c/soc_camera: fix ov6650 sensor getting wrong clock
	timers, sched_clock: Update timeout for clock wrap
	sysrq: Reset the watchdog timers while displaying high-resolution timers
	Input: qt1070 - add OF device ID table
	sched: act_csum: don't mangle TCP and UDP GSO packets
	PCI: hv: Properly handle PCI bus remove
	PCI: hv: Lock PCI bus on device eject
	ASoC: rcar: ssi: don't set SSICR.CKDV = 000 with SSIWSR.CONT
	spi: omap2-mcspi: poll OMAP2_MCSPI_CHSTAT_RXS for PIO transfer
	tcp: sysctl: Fix a race to avoid unexpected 0 window from space
	dmaengine: imx-sdma: add 1ms delay to ensure SDMA channel is stopped
	usb: dwc3: make sure UX_EXIT_PX is cleared
	ARM: dts: bcm2835: add index to the ethernet alias
	perf annotate: Fix a bug following symbolic link of a build-id file
	perf buildid: Do not assume that readlink() returns a null terminated string
	i40e/i40evf: Fix use after free in Rx cleanup path
	scsi: be2iscsi: Check tag in beiscsi_mccq_compl_wait
	driver: (adm1275) set the m,b and R coefficients correctly for power
	bonding: make speed, duplex setting consistent with link state
	mm: Fix false-positive VM_BUG_ON() in page_cache_{get,add}_speculative()
	ALSA: firewire-lib: add a quirk of packet without valid EOH in CIP format
	ARM: dts: r8a7794: Add DU1 clock to device tree
	ARM: dts: r8a7794: Correct clock of DU1
	ARM: dts: silk: Correct clock of DU1
	blk-throttle: make sure expire time isn't too big
	regulator: core: Limit propagation of parent voltage count and list
	perf trace: Handle unpaired raw_syscalls:sys_exit event
	f2fs: relax node version check for victim data in gc
	drm/ttm: never add BO that failed to validate to the LRU list
	bonding: refine bond_fold_stats() wrap detection
	PCI: Apply Cavium ACS quirk only to CN81xx/CN83xx/CN88xx devices
	powerpc/mm/hugetlb: Filter out hugepage size not supported by page table layout
	braille-console: Fix value returned by _braille_console_setup
	drm/vmwgfx: Fixes to vmwgfx_fb
	vxlan: vxlan dev should inherit lowerdev's gso_max_size
	NFC: nfcmrvl: Include unaligned.h instead of access_ok.h
	NFC: nfcmrvl: double free on error path
	NFC: pn533: change order of free_irq and dev unregistration
	ARM: dts: r7s72100: fix ethernet clock parent
	ARM: dts: r8a7790: Correct parent of SSI[0-9] clocks
	ARM: dts: r8a7791: Correct parent of SSI[0-9] clocks
	ARM: dts: r8a7793: Correct parent of SSI[0-9] clocks
	powerpc: Avoid taking a data miss on every userspace instruction miss
	net: hns: Correct HNS RSS key set function
	net/faraday: Add missing include of of.h
	qed: Fix TM block ILT allocation
	rtmutex: Fix PI chain order integrity
	printk: Correctly handle preemption in console_unlock()
	drm: rcar-du: Handle event when disabling CRTCs
	ARM: dts: koelsch: Correct clock frequency of X2 DU clock input
	reiserfs: Make cancel_old_flush() reliable
	ASoC: rt5677: Add OF device ID table
	IB/hfi1: Check for QSFP presence before attempting reads
	ALSA: firewire-digi00x: add support for console models of Digi00x series
	ALSA: firewire-digi00x: handle all MIDI messages on streaming packets
	fm10k: correctly check if interface is removed
	EDAC, altera: Fix peripheral warnings for Cyclone5
	scsi: ses: don't get power status of SES device slot on probe
	qed: Correct MSI-x for storage
	apparmor: Make path_max parameter readonly
	iommu/iova: Fix underflow bug in __alloc_and_insert_iova_range
	kvm/svm: Setup MCG_CAP on AMD properly
	kvm: nVMX: Disallow userspace-injected exceptions in guest mode
	video: ARM CLCD: fix dma allocation size
	drm/radeon: Fail fb creation from imported dma-bufs.
	drm/amdgpu: Fail fb creation from imported dma-bufs. (v2)
	drm/rockchip: vop: Enable pm domain before vop_initial
	i40e: only register client on iWarp-capable devices
	coresight: Fixes coresight DT parse to get correct output port ID.
	lkdtm: turn off kcov for lkdtm_rodata_do_nothing:
	tty: amba-pl011: Fix spurious TX interrupts
	serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off
	MIPS: BPF: Quit clobbering callee saved registers in JIT code.
	MIPS: BPF: Fix multiple problems in JIT skb access helpers.
	MIPS: r2-on-r6-emu: Fix BLEZL and BGTZL identification
	MIPS: r2-on-r6-emu: Clear BLTZALL and BGEZALL debugfs counters
	v4l: vsp1: Prevent multiple streamon race commencing pipeline early
	v4l: vsp1: Register pipe with output WPF
	regulator: isl9305: fix array size
	md/raid6: Fix anomily when recovering a single device in RAID6.
	md.c:didn't unlock the mddev before return EINVAL in array_size_store
	powerpc/nohash: Fix use of mmu_has_feature() in setup_initial_memory_limit()
	usb: dwc2: Make sure we disconnect the gadget state
	usb: gadget: dummy_hcd: Fix wrong power status bit clear/reset in dummy_hub_control()
	perf evsel: Return exact sub event which failed with EPERM for wildcards
	iwlwifi: mvm: fix RX SKB header size and align it properly
	drivers/perf: arm_pmu: handle no platform_device
	perf inject: Copy events when reordering events in pipe mode
	net: fec: add phy-reset-gpios PROBE_DEFER check
	perf session: Don't rely on evlist in pipe mode
	vfio/powerpc/spapr_tce: Enforce IOMMU type compatibility check
	vfio/spapr_tce: Check kzalloc() return when preregistering memory
	scsi: sg: check for valid direction before starting the request
	scsi: sg: close race condition in sg_remove_sfp_usercontext()
	ALSA: hda: Add Geminilake id to SKL_PLUS
	kprobes/x86: Fix kprobe-booster not to boost far call instructions
	kprobes/x86: Set kprobes pages read-only
	pwm: tegra: Increase precision in PWM rate calculation
	clk: qcom: msm8996: Fix the vfe1 powerdomain name
	Bluetooth: Avoid bt_accept_unlink() double unlinking
	Bluetooth: 6lowpan: fix delay work init in add_peer_chan()
	mac80211_hwsim: use per-interface power level
	ath10k: fix compile time sanity check for CE4 buffer size
	wil6210: fix protection against connections during reset
	wil6210: fix memory access violation in wil_memcpy_from/toio_32
	perf stat: Fix bug in handling events in error state
	mwifiex: Fix invalid port issue
	drm/edid: set ELD connector type in drm_edid_to_eld()
	video/hdmi: Allow "empty" HDMI infoframes
	HID: elo: clear BTN_LEFT mapping
	iwlwifi: mvm: rs: don't override the rate history in the search cycle
	clk: meson: gxbb: fix wrong clock for SARADC/SANA
	ARM: dts: exynos: Correct Trats2 panel reset line
	sched: Stop switched_to_rt() from sending IPIs to offline CPUs
	sched: Stop resched_cpu() from sending IPIs to offline CPUs
	test_firmware: fix setting old custom fw path back on exit
	net: ieee802154: adf7242: Fix bug if defined DEBUG
	net: xfrm: allow clearing socket xfrm policies.
	mtd: nand: fix interpretation of NAND_CMD_NONE in nand_command[_lp]()
	net: thunderx: Set max queue count taking XDP_TX into account
	ARM: dts: am335x-pepper: Fix the audio CODEC's reset pin
	ARM: dts: omap3-n900: Fix the audio CODEC's reset pin
	mtd: nand: ifc: update bufnum mask for ver >= 2.0.0
	userns: Don't fail follow_automount based on s_user_ns
	leds: pm8058: Silence pointer to integer size warning
	power: supply: ab8500_charger: Fix an error handling path
	power: supply: ab8500_charger: Bail out in case of error in 'ab8500_charger_init_hw_registers()'
	ath10k: update tdls teardown state to target
	scsi: ses: don't ask for diagnostic pages repeatedly during probe
	pwm: stmpe: Fix wrong register offset for hwpwm=2 case
	clk: qcom: msm8916: fix mnd_width for codec_digcodec
	mwifiex: cfg80211: do not change virtual interface during scan processing
	ath10k: fix invalid STS_CAP_OFFSET_MASK
	tools/usbip: fixes build with musl libc toolchain
	spi: sun6i: disable/unprepare clocks on remove
	bnxt_en: Don't print "Link speed -1 no longer supported" messages.
	scsi: core: scsi_get_device_flags_keyed(): Always return device flags
	scsi: devinfo: apply to HP XP the same flags as Hitachi VSP
	scsi: dh: add new rdac devices
	media: vsp1: Prevent suspending and resuming DRM pipelines
	media: cpia2: Fix a couple off by one bugs
	veth: set peer GSO values
	drm/amdkfd: Fix memory leaks in kfd topology
	powerpc/modules: Don't try to restore r2 after a sibling call
	agp/intel: Flush all chipset writes after updating the GGTT
	mac80211_hwsim: enforce PS_MANUAL_POLL to be set after PS_ENABLED
	mac80211: remove BUG() when interface type is invalid
	ASoC: nuc900: Fix a loop timeout test
	ipvlan: add L2 check for packets arriving via virtual devices
	rcutorture/configinit: Fix build directory error message
	locking/locktorture: Fix num reader/writer corner cases
	ima: relax requiring a file signature for new files with zero length
	net: hns: Some checkpatch.pl script & warning fixes
	x86/boot/32: Fix UP boot on Quark and possibly other platforms
	x86/cpufeatures: Add Intel PCONFIG cpufeature
	selftests/x86/entry_from_vm86: Exit with 1 if we fail
	selftests/x86: Add tests for User-Mode Instruction Prevention
	selftests/x86: Add tests for the STR and SLDT instructions
	selftests/x86/entry_from_vm86: Add test cases for POPF
	x86/vm86/32: Fix POPF emulation
	x86/speculation, objtool: Annotate indirect calls/jumps for objtool on 32-bit kernels
	x86/speculation: Remove Skylake C2 from Speculation Control microcode blacklist
	x86/mm: Fix vmalloc_fault to use pXd_large
	parisc: Handle case where flush_cache_range is called with no context
	ALSA: pcm: Fix UAF in snd_pcm_oss_get_formats()
	ALSA: hda - Revert power_save option default value
	ALSA: seq: Fix possible UAF in snd_seq_check_queue()
	ALSA: seq: Clear client entry before deleting else at closing
	drm/amdgpu: fix prime teardown order
	drm/amdgpu/dce: Don't turn off DP sink when disconnected
	fs: Teach path_connected to handle nfs filesystems with multiple roots.
	lock_parent() needs to recheck if dentry got __dentry_kill'ed under it
	fs/aio: Add explicit RCU grace period when freeing kioctx
	fs/aio: Use RCU accessors for kioctx_table->table[]
	irqchip/gic-v3-its: Ensure nr_ites >= nr_lpis
	scsi: sg: fix SG_DXFER_FROM_DEV transfers
	scsi: sg: fix static checker warning in sg_is_valid_dxfer
	scsi: sg: only check for dxfer_len greater than 256M
	btrfs: alloc_chunk: fix DUP stripe size handling
	btrfs: Fix use-after-free when cleaning up fs_devs with a single stale device
	scsi: qla2xxx: Fix extraneous ref on sp's after adapter break
	USB: gadget: udc: Add missing platform_device_put() on error in bdc_pci_probe()
	usb: dwc3: Fix GDBGFIFOSPACE_TYPE values
	usb: gadget: bdc: 64-bit pointer capability check
	Linux 4.9.89

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-03-22 09:54:47 +01:00
Al Viro
05f16fe9ae lock_parent() needs to recheck if dentry got __dentry_kill'ed under it
commit 3b82140963 upstream.

In case when dentry passed to lock_parent() is protected from freeing only
by the fact that it's on a shrink list and trylock of parent fails, we
could get hit by __dentry_kill() (and subsequent dentry_kill(parent))
between unlocking dentry and locking presumed parent.  We need to recheck
that dentry is alive once we lock both it and parent *and* postpone
rcu_read_unlock() until after that point.  Otherwise we could return
a pointer to struct dentry that already is rcu-scheduled for freeing, with
->d_lock held on it; caller's subsequent attempt to unlock it can end
up with memory corruption.

Cc: stable@vger.kernel.org # 3.12+, counting backports
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22 09:18:00 +01:00
Greg Kroah-Hartman
e6b0c64f6f Merge 4.9.41 into android-4.9
Changes in 4.9.41
	af_key: Add lock to key dump
	pstore: Make spinlock per zone instead of global
	net: reduce skb_warn_bad_offload() noise
	jfs: Don't clear SGID when inheriting ACLs
	ALSA: fm801: Initialize chip after IRQ handler is registered
	ALSA: hda - Add missing NVIDIA GPU codec IDs to patch table
	parisc: Prevent TLB speculation on flushed pages on CPUs that only support equivalent aliases
	parisc: Extend disabled preemption in copy_user_page
	parisc: Suspend lockup detectors before system halt
	powerpc/pseries: Fix of_node_put() underflow during reconfig remove
	NFS: invalidate file size when taking a lock.
	NFSv4.1: Fix a race where CB_NOTIFY_LOCK fails to wake a waiter
	crypto: authencesn - Fix digest_null crash
	KVM: PPC: Book3S HV: Enable TM before accessing TM registers
	md/raid5: add thread_group worker async_tx_issue_pending_all
	drm/vmwgfx: Fix gcc-7.1.1 warning
	drm/nouveau/disp/nv50-: bump max chans to 21
	drm/nouveau/bar/gf100: fix access to upper half of BAR2
	KVM: PPC: Book3S HV: Restore critical SPRs to host values on guest exit
	KVM: PPC: Book3S HV: Save/restore host values of debug registers
	Revert "powerpc/numa: Fix percpu allocations to be NUMA aware"
	Staging: comedi: comedi_fops: Avoid orphaned proc entry
	drm: rcar-du: Simplify and fix probe error handling
	smp/hotplug: Move unparking of percpu threads to the control CPU
	smp/hotplug: Replace BUG_ON and react useful
	nfc: Fix hangup of RC-S380* in port100_send_ack()
	nfc: fdp: fix NULL pointer dereference
	net: phy: Do not perform software reset for Generic PHY
	isdn: Fix a sleep-in-atomic bug
	isdn/i4l: fix buffer overflow
	ath10k: fix null deref on wmi-tlv when trying spectral scan
	wil6210: fix deadlock when using fw_no_recovery option
	mailbox: always wait in mbox_send_message for blocking Tx mode
	mailbox: skip complete wait event if timer expired
	mailbox: handle empty message in tx_tick
	sched/cgroup: Move sched_online_group() back into css_online() to fix crash
	RDMA/uverbs: Fix the check for port number
	ipmi/watchdog: fix watchdog timeout set on reboot
	dentry name snapshots
	v4l: s5c73m3: fix negation operator
	pstore: Allow prz to control need for locking
	pstore: Correctly initialize spinlock and flags
	pstore: Use dynamic spinlock initializer
	net: skb_needs_check() accepts CHECKSUM_NONE for tx
	device-dax: fix sysfs duplicate warnings
	x86/mce/AMD: Make the init code more robust
	r8169: add support for RTL8168 series add-on card.
	ARM: omap2+: fixing wrong strcat for Non-NULL terminated string
	dt-bindings: power/supply: Update TPS65217 properties
	dt-bindings: input: Specify the interrupt number of TPS65217 power button
	ARM: dts: am57xx-idk: Put USB2 port in peripheral mode
	ARM: dts: n900: Mark eMMC slot with no-sdio and no-sd flags
	net/mlx5: Disable RoCE on the e-switch management port under switchdev mode
	ipv6: Should use consistent conditional judgement for ip6 fragment between __ip6_append_data and ip6_finish_output
	net/mlx4_core: Use-after-free causes a resource leak in flow-steering detach
	net/mlx4: Remove BUG_ON from ICM allocation routine
	net/mlx4_core: Fix raw qp flow steering rules under SRIOV
	drm/msm: Ensure that the hardware write pointer is valid
	drm/msm: Put back the vaddr in submit_reloc()
	drm/msm: Verify that MSM_SUBMIT_BO_FLAGS are set
	vfio-pci: use 32-bit comparisons for register address for gcc-4.5
	irqchip/keystone: Fix "scheduling while atomic" on rt
	ASoC: tlv320aic3x: Mark the RESET register as volatile
	spi: dw: Make debugfs name unique between instances
	ASoC: nau8825: fix invalid configuration in Pre-Scalar of FLL
	irqchip/mxs: Enable SKIP_SET_WAKE and MASK_ON_SUSPEND
	openrisc: Add _text symbol to fix ksym build error
	dmaengine: ioatdma: Add Skylake PCI Dev ID
	dmaengine: ioatdma: workaround SKX ioatdma version
	l2tp: consider '::' as wildcard address in l2tp_ip6 socket lookup
	dmaengine: ti-dma-crossbar: Add some 'of_node_put()' in error path.
	usb: dwc3: omap: fix race of pm runtime with irq handler in probe
	ARM64: zynqmp: Fix W=1 dtc 1.4 warnings
	ARM64: zynqmp: Fix i2c node's compatible string
	perf probe: Fix to get correct modname from elf header
	ARM: s3c2410_defconfig: Fix invalid values for NF_CT_PROTO_*
	ACPI / scan: Prefer devices without _HID/_CID for _ADR matching
	usb: gadget: Fix copy/pasted error message
	Btrfs: use down_read_nested to make lockdep silent
	Btrfs: fix lockdep warning about log_mutex
	benet: stricter vxlan offloading check in be_features_check
	Btrfs: adjust outstanding_extents counter properly when dio write is split
	Xen: ARM: Zero reserved fields of xatp before making hypervisor call
	tools lib traceevent: Fix prev/next_prio for deadline tasks
	xfrm: Don't use sk_family for socket policy lookups
	perf tools: Install tools/lib/traceevent plugins with install-bin
	perf symbols: Robustify reading of build-id from sysfs
	video: fbdev: cobalt_lcdfb: Handle return NULL error from devm_ioremap
	vfio-pci: Handle error from pci_iomap
	arm64: mm: fix show_pte KERN_CONT fallout
	nvmem: imx-ocotp: Fix wrong register size
	net: usb: asix_devices: add .reset_resume for USB PM
	ASoC: fsl_ssi: set fifo watermark to more reliable value
	sh_eth: enable RX descriptor word 0 shift on SH7734
	ARCv2: IRQ: Call entry/exit functions for chained handlers in MCIP
	ALSA: usb-audio: test EP_FLAG_RUNNING at urb completion
	x86/platform/intel-mid: Rename 'spidev' to 'mrfld_spidev'
	perf/x86: Set pmu->module in Intel PMU modules
	ASoC: Intel: bytcr-rt5640: fix settings in internal clock mode
	HID: ignore Petzl USB headlamp
	scsi: fnic: Avoid sending reset to firmware when another reset is in progress
	scsi: snic: Return error code on memory allocation failure
	scsi: bfa: Increase requested firmware version to 3.2.5.1
	ASoC: Intel: Skylake: Release FW ctx in cleanup
	ASoC: dpcm: Avoid putting stream state to STOP when FE stream is paused
	Linux 4.9.41

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2017-08-07 14:21:32 -07:00
Al Viro
ad25f11ed2 dentry name snapshots
commit 49d31c2f38 upstream.

take_dentry_name_snapshot() takes a safe snapshot of dentry name;
if the name is a short one, it gets copied into caller-supplied
structure, otherwise an extra reference to external name is grabbed
(those are never modified).  In either case the pointer to stable
string is stored into the same structure.

dentry must be held by the caller of take_dentry_name_snapshot(),
but may be freely dropped afterwards - the snapshot will stay
until destroyed by release_dentry_name_snapshot().

Intended use:
	struct name_snapshot s;

	take_dentry_name_snapshot(&s, dentry);
	...
	access s.name
	...
	release_dentry_name_snapshot(&s);

Replaces fsnotify_oldname_...(), gets used in fsnotify to obtain the name
to pass down with event.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-06 18:59:43 -07:00
Greg Kroah-Hartman
14accea70e Merge 4.9.39 into android-4.9
Changes in 4.9.39
	xen-netfront: Rework the fix for Rx stall during OOM and network stress
	net_sched: fix error recovery at qdisc creation
	net: sched: Fix one possible panic when no destroy callback
	net/phy: micrel: configure intterupts after autoneg workaround
	ipv6: avoid unregistering inet6_dev for loopback
	net: dp83640: Avoid NULL pointer dereference.
	tcp: reset sk_rx_dst in tcp_disconnect()
	net: prevent sign extension in dev_get_stats()
	bridge: mdb: fix leak on complete_info ptr on fail path
	rocker: move dereference before free
	bpf: prevent leaking pointer via xadd on unpriviledged
	net: handle NAPI_GRO_FREE_STOLEN_HEAD case also in napi_frags_finish()
	net/mlx5: Cancel delayed recovery work when unloading the driver
	liquidio: fix bug in soft reset failure detection
	net/mlx5e: Fix TX carrier errors report in get stats ndo
	ipv6: dad: don't remove dynamic addresses if link is down
	vxlan: fix hlist corruption
	net: core: Fix slab-out-of-bounds in netdev_stats_to_stats64
	net: ipv6: Compare lwstate in detecting duplicate nexthops
	vrf: fix bug_on triggered by rx when destroying a vrf
	rds: tcp: use sock_create_lite() to create the accept socket
	brcmfmac: fix possible buffer overflow in brcmf_cfg80211_mgmt_tx()
	brcmfmac: Fix a memory leak in error handling path in 'brcmf_cfg80211_attach'
	brcmfmac: Fix glom_skb leak in brcmf_sdiod_recv_chain
	sfc: don't read beyond unicast address list
	cfg80211: Define nla_policy for NL80211_ATTR_LOCAL_MESH_POWER_MODE
	cfg80211: Validate frequencies nested in NL80211_ATTR_SCAN_FREQUENCIES
	cfg80211: Check if PMKID attribute is of expected size
	cfg80211: Check if NAN service ID is of expected size
	irqchip/gic-v3: Fix out-of-bound access in gic_set_affinity
	parisc: Report SIGSEGV instead of SIGBUS when running out of stack
	parisc: use compat_sys_keyctl()
	parisc: DMA API: return error instead of BUG_ON for dma ops on non dma devs
	parisc/mm: Ensure IRQs are off in switch_mm()
	tools/lib/lockdep: Reduce MAX_LOCK_DEPTH to avoid overflowing lock_chain/: Depth
	thp, mm: fix crash due race in MADV_FREE handling
	kernel/extable.c: mark core_kernel_text notrace
	mm/list_lru.c: fix list_lru_count_node() to be race free
	fs/dcache.c: fix spin lockup issue on nlru->lock
	checkpatch: silence perl 5.26.0 unescaped left brace warnings
	binfmt_elf: use ELF_ET_DYN_BASE only for PIE
	arm: move ELF_ET_DYN_BASE to 4MB
	arm64: move ELF_ET_DYN_BASE to 4GB / 4MB
	powerpc: move ELF_ET_DYN_BASE to 4GB / 4MB
	s390: reduce ELF_ET_DYN_BASE
	exec: Limit arg stack to at most 75% of _STK_LIM
	ARM64: dts: marvell: armada37xx: Fix timer interrupt specifiers
	vt: fix unchecked __put_user() in tioclinux ioctls
	rcu: Add memory barriers for NOCB leader wakeup
	nvmem: core: fix leaks on registration errors
	mnt: In umount propagation reparent in a separate pass
	mnt: In propgate_umount handle visiting mounts in any order
	mnt: Make propagate_umount less slow for overlapping mount propagation trees
	selftests/capabilities: Fix the test_execve test
	mm: fix overflow check in expand_upwards()
	crypto: talitos - Extend max key length for SHA384/512-HMAC and AEAD
	crypto: atmel - only treat EBUSY as transient if backlog
	crypto: sha1-ssse3 - Disable avx2
	crypto: caam - properly set IV after {en,de}crypt
	crypto: caam - fix signals handling
	Revert "sched/core: Optimize SCHED_SMT"
	sched/fair, cpumask: Export for_each_cpu_wrap()
	sched/topology: Fix building of overlapping sched-groups
	sched/topology: Optimize build_group_mask()
	sched/topology: Fix overlapping sched_group_mask
	PM / wakeirq: Convert to SRCU
	PM / QoS: return -EINVAL for bogus strings
	tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results
	kvm: vmx: Do not disable intercepts for BNDCFGS
	kvm: x86: Guest BNDCFGS requires guest MPX support
	kvm: vmx: Check value written to IA32_BNDCFGS
	kvm: vmx: allow host to access guest MSR_IA32_BNDCFGS
	4.9.39

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2017-07-21 08:55:50 +02:00
Sahitya Tummala
a9aa6522a1 fs/dcache.c: fix spin lockup issue on nlru->lock
commit b17c070fb6 upstream.

__list_lru_walk_one() acquires nlru spin lock (nlru->lock) for longer
duration if there are more number of items in the lru list.  As per the
current code, it can hold the spin lock for upto maximum UINT_MAX
entries at a time.  So if there are more number of items in the lru
list, then "BUG: spinlock lockup suspected" is observed in the below
path:

  spin_bug+0x90
  do_raw_spin_lock+0xfc
  _raw_spin_lock+0x28
  list_lru_add+0x28
  dput+0x1c8
  path_put+0x20
  terminate_walk+0x3c
  path_lookupat+0x100
  filename_lookup+0x6c
  user_path_at_empty+0x54
  SyS_faccessat+0xd0
  el0_svc_naked+0x24

This nlru->lock is acquired by another CPU in this path -

  d_lru_shrink_move+0x34
  dentry_lru_isolate_shrink+0x48
  __list_lru_walk_one.isra.10+0x94
  list_lru_walk_node+0x40
  shrink_dcache_sb+0x60
  do_remount_sb+0xbc
  do_emergency_remount+0xb0
  process_one_work+0x228
  worker_thread+0x2e0
  kthread+0xf4
  ret_from_fork+0x10

Fix this lockup by reducing the number of entries to be shrinked from
the lru list to 1024 at once.  Also, add cond_resched() before
processing the lru list again.

Link: http://marc.info/?t=149722864900001&r=1&w=2
Link: http://lkml.kernel.org/r/1498707575-2472-1-git-send-email-stummala@codeaurora.org
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Suggested-by: Jan Kara <jack@suse.cz>
Suggested-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Alexander Polakov <apolyakov@beget.ru>
Cc: Al Viro <viro@zeniv.linux.org.uk>
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>
2017-07-21 07:42:21 +02:00
Dmitry Shmidt
cd08287396 Merge tag 'v4.9.6' into android-4.9
This is the 4.9.6 stable release

Change-Id: I318df4b9d706d50c13fe3969d734117c25fc94bc
2017-01-31 13:55:27 -08:00
Guenter Roeck
671662bd63 ANDROID: fs: Export d_absolute_path
The 0-day build bot reports the following build error, seen if SDCARD_FS
is built as module.

ERROR: "d_absolute_path" undefined!

Fixes: 84a1b7d3d3 ("Included sdcardfs source code for kernel 3.0")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Guenter Roeck <groeck@chromium.org>
2017-01-27 13:54:55 -08:00
Eric W. Biederman
1a62a0f765 mnt: Protect the mountpoint hashtable with mount_lock
commit 3895dbf898 upstream.

Protecting the mountpoint hashtable with namespace_sem was sufficient
until a call to umount_mnt was added to mntput_no_expire.  At which
point it became possible for multiple calls of put_mountpoint on
the same hash chain to happen on the same time.

Kristen Johansen <kjlx@templeofstupid.com> reported:
> This can cause a panic when simultaneous callers of put_mountpoint
> attempt to free the same mountpoint.  This occurs because some callers
> hold the mount_hash_lock, while others hold the namespace lock.  Some
> even hold both.
>
> In this submitter's case, the panic manifested itself as a GP fault in
> put_mountpoint() when it called hlist_del() and attempted to dereference
> a m_hash.pprev that had been poisioned by another thread.

Al Viro observed that the simple fix is to switch from using the namespace_sem
to the mount_lock to protect the mountpoint hash table.

I have taken Al's suggested patch moved put_mountpoint in pivot_root
(instead of taking mount_lock an additional time), and have replaced
new_mountpoint with get_mountpoint a function that does the hash table
lookup and addition under the mount_lock.   The introduction of get_mounptoint
ensures that only the mount_lock is needed to manipulate the mountpoint
hashtable.

d_set_mounted is modified to only set DCACHE_MOUNTED if it is not
already set.  This allows get_mountpoint to use the setting of
DCACHE_MOUNTED to ensure adding a struct mountpoint for a dentry
happens exactly once.

Fixes: ce07d891a0 ("mnt: Honor MNT_LOCKED when detaching mounts")
Reported-by: Krister Johansen <kjlx@templeofstupid.com>
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19 20:18:03 +01:00
Linus Torvalds
fe64f3283f Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Assorted cleanups and fixes.

  In the "trivial API change" department - ->d_compare() losing 'parent'
  argument"

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  cachefiles: Fix race between inactivating and culling a cache object
  9p: use clone_fid()
  9p: fix braino introduced in "9p: new helper - v9fs_parent_fid()"
  vfs: make dentry_needs_remove_privs() internal
  vfs: remove file_needs_remove_privs()
  vfs: fix deadlock in file_remove_privs() on overlayfs
  get rid of 'parent' argument of ->d_compare()
  cifs, msdos, vfat, hfs+: don't bother with parent in ->d_compare()
  affs ->d_compare(): don't bother with ->d_inode
  fold _d_rehash() and __d_rehash() together
  fold dentry_rcuwalk_invalidate() into its only remaining caller
2016-08-07 10:01:14 -04:00
Linus Torvalds
835c92d43b Merge branch 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull qstr constification updates from Al Viro:
 "Fairly self-contained bunch - surprising lot of places passes struct
  qstr * as an argument when const struct qstr * would suffice; it
  complicates analysis for no good reason.

  I'd prefer to feed that separately from the assorted fixes (those are
  in #for-linus and with somewhat trickier topology)"

* 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  qstr: constify instances in adfs
  qstr: constify instances in lustre
  qstr: constify instances in f2fs
  qstr: constify instances in ext2
  qstr: constify instances in vfat
  qstr: constify instances in procfs
  qstr: constify instances in fuse
  qstr constify instances in fs/dcache.c
  qstr: constify instances in nfs
  qstr: constify instances in ocfs2
  qstr: constify instances in autofs4
  qstr: constify instances in hfs
  qstr: constify instances in hfsplus
  qstr: constify instances in logfs
  qstr: constify dentry_init_security
2016-08-06 09:49:02 -04:00
Al Viro
6fa67e7075 get rid of 'parent' argument of ->d_compare()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-31 16:37:25 -04:00
Al Viro
15d3c589f6 fold _d_rehash() and __d_rehash() together
The only place where we feed to __d_rehash() something other than
d_hash(dentry->d_name.hash) is __d_move(), where we give it d_hash
of another dentry.  Postpone rehashing until we'd switched the
names and we are rid of that exception, along with the need to
keep _d_rehash() and __d_rehash() separate.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-29 17:45:21 -04:00
Al Viro
d614146d18 fold dentry_rcuwalk_invalidate() into its only remaining caller
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-29 17:28:58 -04:00
Linus Torvalds
6784725ab0 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "Assorted cleanups and fixes.

  Probably the most interesting part long-term is ->d_init() - that will
  have a bunch of followups in (at least) ceph and lustre, but we'll
  need to sort the barrier-related rules before it can get used for
  really non-trivial stuff.

  Another fun thing is the merge of ->d_iput() callers (dentry_iput()
  and dentry_unlink_inode()) and a bunch of ->d_compare() ones (all
  except the one in __d_lookup_lru())"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
  fs/dcache.c: avoid soft-lockup in dput()
  vfs: new d_init method
  vfs: Update lookup_dcache() comment
  bdev: get rid of ->bd_inodes
  Remove last traces of ->sync_page
  new helper: d_same_name()
  dentry_cmp(): use lockless_dereference() instead of smp_read_barrier_depends()
  vfs: clean up documentation
  vfs: document ->d_real()
  vfs: merge .d_select_inode() into .d_real()
  unify dentry_iput() and dentry_unlink_inode()
  binfmt_misc: ->s_root is not going anywhere
  drop redundant ->owner initializations
  ufs: get rid of redundant checks
  orangefs: constify inode_operations
  missed comment updates from ->direct_IO() prototype change
  file_inode(f)->i_mapping is f->f_mapping
  trim fsnotify hooks a bit
  9p: new helper - v9fs_parent_fid()
  debugfs: ->d_parent is never NULL or negative
  ...
2016-07-28 12:59:05 -07:00
Linus Torvalds
554828ee0d Merge branch 'salted-string-hash'
This changes the vfs dentry hashing to mix in the parent pointer at the
_beginning_ of the hash, rather than at the end.

That actually improves both the hash and the code generation, because we
can move more of the computation to the "static" part of the dcache
setup, and do less at lookup runtime.

It turns out that a lot of other hash users also really wanted to mix in
a base pointer as a 'salt' for the hash, and so the slightly extended
interface ends up working well for other cases too.

Users that want a string hash that is purely about the string pass in a
'salt' pointer of NULL.

* merge branch 'salted-string-hash':
  fs/dcache.c: Save one 32-bit multiply in dcache lookup
  vfs: make the string hashes salt the hash
2016-07-28 12:26:31 -07:00
Wei Fang
47be61845c fs/dcache.c: avoid soft-lockup in dput()
We triggered soft-lockup under stress test which
open/access/write/close one file concurrently on more than
five different CPUs:

WARN: soft lockup - CPU#0 stuck for 11s! [who:30631]
...
[<ffffffc0003986f8>] dput+0x100/0x298
[<ffffffc00038c2dc>] terminate_walk+0x4c/0x60
[<ffffffc00038f56c>] path_lookupat+0x5cc/0x7a8
[<ffffffc00038f780>] filename_lookup+0x38/0xf0
[<ffffffc000391180>] user_path_at_empty+0x78/0xd0
[<ffffffc0003911f4>] user_path_at+0x1c/0x28
[<ffffffc00037d4fc>] SyS_faccessat+0xb4/0x230

->d_lock trylock may failed many times because of concurrently
operations, and dput() may execute a long time.

Fix this by replacing cpu_relax() with cond_resched().
dput() used to be sleepable, so make it sleepable again
should be safe.

Cc: <stable@vger.kernel.org>
Signed-off-by: Wei Fang <fangwei1@huawei.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-24 16:37:16 -04:00
Miklos Szeredi
285b102d3b vfs: new d_init method
Allow filesystem to initialize dentry at allocation time.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-24 16:36:29 -04:00
Al Viro
17648b871d Merge branch 'test.d_iput' into work.misc 2016-07-24 16:36:04 -04:00
Al Viro
9aba36dea5 qstr constify instances in fs/dcache.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-20 23:30:06 -04:00
Al Viro
b223f4e215 Merge branch 'd_real' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into work.misc 2016-06-30 23:34:49 -04:00
Al Viro
d4c91a8f7e new helper: d_same_name()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-30 23:30:44 -04:00
He Kuang
ae0a843c74 dentry_cmp(): use lockless_dereference() instead of smp_read_barrier_depends()
lockless_dereference() was added which can be used in place of
hard-coding smp_read_barrier_depends().

Signed-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-30 23:30:35 -04:00
Al Viro
c074cefcc0 Merge branch 'for-linus' into work.misc 2016-06-30 23:30:06 -04:00
Miklos Szeredi
2d902671ce vfs: merge .d_select_inode() into .d_real()
The two methods essentially do the same: find the real dentry/inode
belonging to an overlay dentry.  The difference is in the usage:

vfs_open() uses ->d_select_inode() and expects the function to perform
copy-up if necessary based on the open flags argument.

file_dentry() uses ->d_real() passing in the overlay dentry as well as the
underlying inode.

vfs_rename() uses ->d_select_inode() but passes zero flags.  ->d_real()
with a zero inode would have worked just as well here.

This patch merges the functionality of ->d_select_inode() into ->d_real()
by adding an 'open_flags' argument to the latter.

[Al Viro] Make the signature of d_real() match that of ->d_real() again.
And constify the inode argument, while we are at it.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-06-30 08:53:27 +02:00
Al Viro
e7d6ef9790 fix idiotic braino in d_alloc_parallel()
Check for d_unhashed() while searching in in-lookup hash was absolutely
wrong.  Worse, it masked a deadlock on dget() done under bitlock that
nests inside ->d_lock.  Thanks to J. R. Okajima for spotting it.

Spotted-by: "J. R. Okajima" <hooanon05g@gmail.com>
Wearing-brown-paperbag: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-20 10:07:42 -04:00
George Spelvin
703b5faf22 fs/dcache.c: Save one 32-bit multiply in dcache lookup
Noe that we're mixing in the parent pointer earlier, we
don't need to use hash_32() to mix its bits.  Instead, we can
just take the msbits of the hash value directly.

For those applications which use the partial_name_hash(),
move the multiply to end_name_hash.

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-11 14:57:56 -07:00
Linus Torvalds
8387ff2577 vfs: make the string hashes salt the hash
We always mixed in the parent pointer into the dentry name hash, but we
did it late at lookup time.  It turns out that we can simplify that
lookup-time action by salting the hash with the parent pointer early
instead of late.

A few other users of our string hashes also wanted to mix in their own
pointers into the hash, and those are updated to use the same mechanism.

Hash users that don't have any particular initial salt can just use the
NULL pointer as a no-salt.

Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-10 20:21:46 -07:00
Al Viro
ba65dc5ef1 much milder d_walk() race
d_walk() relies upon the tree not getting rearranged under it without
rename_lock being touched.  And we do grab rename_lock around the
places that change the tree topology.  Unfortunately, branch reordering
is just as bad from d_walk() POV and we have two places that do it
without touching rename_lock - one in handling of cursors (for ramfs-style
directories) and another in autofs.  autofs one is a separate story; this
commit deals with the cursors.
	* mark cursor dentries explicitly at allocation time
	* make __dentry_kill() leave ->d_child.next pointing to the next
non-cursor sibling, making sure that it won't be moved around unnoticed
before the parent is relocked on ascend-to-parent path in d_walk().
	* make d_walk() skip cursors explicitly; strictly speaking it's
not necessary (all callbacks we pass to d_walk() are no-ops on cursors),
but it makes analysis easier.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-10 11:32:47 -04:00
Al Viro
3d56c25e3b fix d_walk()/non-delayed __d_free() race
Ascend-to-parent logics in d_walk() depends on all encountered child
dentries not getting freed without an RCU delay.  Unfortunately, in
quite a few cases it is not true, with hard-to-hit oopsable race as
the result.

Fortunately, the fix is simiple; right now the rule is "if it ever
been hashed, freeing must be delayed" and changing it to "if it
ever had a parent, freeing must be delayed" closes that hole and
covers all cases the old rule used to cover.  Moreover, pipes and
sockets remain _not_ covered, so we do not introduce RCU delay in
the cases which are the reason for having that delay conditional
in the first place.

Cc: stable@vger.kernel.org # v3.2+ (and watch out for __d_materialise_dentry())
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-07 21:26:55 -04:00
Al Viro
550dce01dd unify dentry_iput() and dentry_unlink_inode()
There is a lot of duplication between dentry_unlink_inode() and dentry_iput().
The only real difference is that dentry_unlink_inode() bumps ->d_seq and
dentry_iput() doesn't.  The argument of the latter is known to have been
unhashed, so anybody who might've found it in RCU lookup would already be
doomed to a ->d_seq mismatch.  And we want to avoid pointless smp_rmb() there.

This patch makes dentry_unlink_inode() bump ->d_seq only for hashed dentries.
It's safe (d_delete() calls that sucker only if we are holding the only
reference to dentry, so rehash is not going to happen) and it allows
to use dentry_unlink_inode() in __dentry_kill() and get rid of dentry_iput().

The interesting question here is profiling; it *is* a hot path, and extra
conditional jumps in there might or might not be painful.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-29 20:28:22 -04:00
Al Viro
affda48410 trim fsnotify hooks a bit
fsnotify_d_move()/__fsnotify_d_instantiate()/__fsnotify_update_dcache_flags()
are identical to each other, regardless of the config.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-29 18:35:12 -04:00
Linus Torvalds
7e0fb73c52 Merge branch 'hash' of git://ftp.sciencehorizons.net/linux
Pull string hash improvements from George Spelvin:
 "This series does several related things:

   - Makes the dcache hash (fs/namei.c) useful for general kernel use.

     (Thanks to Bruce for noticing the zero-length corner case)

   - Converts the string hashes in <linux/sunrpc/svcauth.h> to use the
     above.

   - Avoids 64-bit multiplies in hash_64() on 32-bit platforms.  Two
     32-bit multiplies will do well enough.

   - Rids the world of the bad hash multipliers in hash_32.

     This finishes the job started in commit 689de1d6ca ("Minimal
     fix-up of bad hashing behavior of hash_64()")

     The vast majority of Linux architectures have hardware support for
     32x32-bit multiply and so derive no benefit from "simplified"
     multipliers.

     The few processors that do not (68000, h8/300 and some models of
     Microblaze) have arch-specific implementations added.  Those
     patches are last in the series.

   - Overhauls the dcache hash mixing.

     The patch in commit 0fed3ac866 ("namei: Improve hash mixing if
     CONFIG_DCACHE_WORD_ACCESS") was an off-the-cuff suggestion.
     Replaced with a much more careful design that's simultaneously
     faster and better.  (My own invention, as there was noting suitable
     in the literature I could find.  Comments welcome!)

   - Modify the hash_name() loop to skip the initial HASH_MIX().  This
     would let us salt the hash if we ever wanted to.

   - Sort out partial_name_hash().

     The hash function is declared as using a long state, even though
     it's truncated to 32 bits at the end and the extra internal state
     contributes nothing to the result.  And some callers do odd things:

      - fs/hfs/string.c only allocates 32 bits of state
      - fs/hfsplus/unicode.c uses it to hash 16-bit unicode symbols not bytes

   - Modify bytemask_from_count to handle inputs of 1..sizeof(long)
     rather than 0..sizeof(long)-1.  This would simplify users other
     than full_name_hash"

  Special thanks to Bruce Fields for testing and finding bugs in v1.  (I
  learned some humbling lessons about "obviously correct" code.)

  On the arch-specific front, the m68k assembly has been tested in a
  standalone test harness, I've been in contact with the Microblaze
  maintainers who mostly don't care, as the hardware multiplier is never
  omitted in real-world applications, and I haven't heard anything from
  the H8/300 world"

* 'hash' of git://ftp.sciencehorizons.net/linux:
  h8300: Add <asm/hash.h>
  microblaze: Add <asm/hash.h>
  m68k: Add <asm/hash.h>
  <linux/hash.h>: Add support for architecture-specific functions
  fs/namei.c: Improve dcache hash function
  Eliminate bad hash multipliers from hash_32() and  hash_64()
  Change hash_64() return value to 32 bits
  <linux/sunrpc/svcauth.h>: Define hash_str() in terms of hashlen_string()
  fs/namei.c: Add hashlen_string() function
  Pull out string hash to <linux/stringhash.h>
2016-05-28 16:15:25 -07:00
George Spelvin
fcfd2fbf22 fs/namei.c: Add hashlen_string() function
We'd like to make more use of the highly-optimized dcache hash functions
throughout the kernel, rather than have every subsystem create its own,
and a function that hashes basic null-terminated strings is required
for that.

(The name is to emphasize that it returns both hash and length.)

It's actually useful in the dcache itself, specifically d_alloc_name().
Other uses in the next patch.

full_name_hash() is also tweaked to make it more generally useful:
1) Take a "char *" rather than "unsigned char *" argument, to
   be consistent with hash_name().
2) Handle zero-length inputs.  If we want more callers, we don't want
   to make them worry about corner cases.

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
2016-05-28 15:42:50 -04:00
Linus Torvalds
9e17632c0a Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs cleanups from Al Viro:
 "Assorted cleanups and fixes all over the place"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  coredump: only charge written data against RLIMIT_CORE
  coredump: get rid of coredump_params->written
  ecryptfs_lookup(): try either only encrypted or plaintext name
  ecryptfs: avoid multiple aliases for directories
  bpf: reject invalid names right in ->lookup()
  __d_alloc(): treat NULL name as QSTR("/", 1)
  mtd: switch ubi_open_volume_path() to vfs_stat()
  mtd: switch open_mtd_by_chdev() to use of vfs_stat()
2016-05-18 11:51:59 -07:00
Al Viro
9902af79c0 parallel lookups: actual switch to rwsem
ta-da!

The main issue is the lack of down_write_killable(), so the places
like readdir.c switched to plain inode_lock(); once killable
variants of rwsem primitives appear, that'll be dealt with.

lockdep side also might need more work

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:49:28 -04:00
Al Viro
d9171b9345 parallel lookups machinery, part 4 (and last)
If we *do* run into an in-lookup match, we need to wait for it to
cease being in-lookup.  Fortunately, we do have unused space in
in-lookup dentries - d_lru is never looked at until it stops being
in-lookup.

So we can stash a pointer to wait_queue_head from stack frame of
the caller of ->lookup().  Some precautions are needed while
waiting, but it's not that hard - we do hold a reference to dentry
we are waiting for, so it can't go away.  If it's found to be
in-lookup the wait_queue_head is still alive and will remain so
at least while ->d_lock is held.  Moreover, the condition we
are waiting for becomes true at the same point where everything
on that wq gets woken up, so we can just add ourselves to the
queue once.

d_alloc_parallel() gets a pointer to wait_queue_head_t from its
caller; lookup_slow() adjusted, d_add_ci() taught to use
d_alloc_parallel() if the dentry passed to it happens to be
in-lookup one (i.e. if it's been called from the parallel lookup).

That's pretty much it - all that remains is to switch ->i_mutex
to rwsem and have lookup_slow() take it shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:49:27 -04:00
Al Viro
94bdd655ca parallel lookups machinery, part 3
We will need to be able to check if there is an in-lookup
dentry with matching parent/name.  Right now it's impossible,
but as soon as start locking directories shared such beasts
will appear.

Add a secondary hash for locating those.  Hash chains go through
the same space where d_alias will be once it's not in-lookup anymore.
Search is done under the same bitlock we use for modifications -
with the primary hash we can rely on d_rehash() into the wrong
chain being the worst that could happen, but here the pointers are
buggered once it's removed from the chain.  On the other hand,
the chains are not going to be long and normally we'll end up
adding to the chain anyway.  That allows us to avoid bothering with
->d_lock when doing the comparisons - everything is stable until
removed from chain.

New helper: d_alloc_parallel().  Right now it allocates, verifies
that no hashed and in-lookup matches exist and adds to in-lookup
hash.

Returns ERR_PTR() for error, hashed match (in the unlikely case it's
been found) or new dentry.  In-lookup matches trigger BUG() for
now; that will change in the next commit when we introduce waiting
for ongoing lookup to finish.  Note that in-lookup matches won't be
possible until we actually go for shared locking.

lookup_slow() switched to use of d_alloc_parallel().

Again, these commits are separated only for making it easier to
review.  All this machinery will start doing something useful only
when we go for shared locking; it's just that the combination is
too large for my taste.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:49:27 -04:00
Al Viro
84e710da2a parallel lookups machinery, part 2
We'll need to verify that there's neither a hashed nor in-lookup
dentry with desired parent/name before adding to in-lookup set.

One possible solution would be to hold the parent's ->d_lock through
both checks, but while the in-lookup set is relatively small at any
time, dcache is not.  And holding the parent's ->d_lock through
something like __d_lookup_rcu() would suck too badly.

So we leave the parent's ->d_lock alone, which means that we watch
out for the following scenario:
	* we verify that there's no hashed match
	* existing in-lookup match gets hashed by another process
	* we verify that there's no in-lookup matches and decide
that everything's fine.

Solution: per-directory kinda-sorta seqlock, bumped around the times
we hash something that used to be in-lookup or move (and hash)
something in place of in-lookup.  Then the above would turn into
	* read the counter
	* do dcache lookup
	* if no matches found, check for in-lookup matches
	* if there had been none of those either, check if the
counter has changed; repeat if it has.

The "kinda-sorta" part is due to the fact that we don't have much spare
space in inode.  There is a spare word (shared with i_bdev/i_cdev/i_pipe),
so the counter part is not a problem, but spinlock is a different story.

We could use the parent's ->d_lock, and it would be less painful in
terms of contention, for __d_add() it would be rather inconvenient to
grab; we could do that (using lock_parent()), but...

Fortunately, we can get serialization on the counter itself, and it
might be a good idea in general; we can use cmpxchg() in a loop to
get from even to odd and smp_store_release() from odd to even.

This commit adds the counter and updating logics; the readers will be
added in the next commit.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:49:26 -04:00