Neil Horman
2d8bff1269
netpoll: Close race condition between poll_one_napi and napi_disable ...
Drivers might call napi_disable while not holding the napi instance poll_lock.
In those instances, its possible for a race condition to exist between
poll_one_napi and napi_disable. That is to say, poll_one_napi only tests the
NAPI_STATE_SCHED bit to see if there is work to do during a poll, and as such
the following may happen:
CPU0 CPU1
ndo_tx_timeout napi_poll_dev
napi_disable poll_one_napi
test_and_set_bit (ret 0)
test_bit (ret 1)
reset adapter napi_poll_routine
If the adapter gets a tx timeout without a napi instance scheduled, its possible
for the adapter to think it has exclusive access to the hardware (as the napi
instance is now scheduled via the napi_disable call), while the netpoll code
thinks there is simply work to do. The result is parallel hardware access
leading to corrupt data structures in the driver, and a crash.
Additionaly, there is another, more critical race between netpoll and
napi_disable. The disabled napi state is actually identical to the scheduled
state for a given napi instance. The implication being that, if a napi instance
is disabled, a netconsole instance would see the napi state of the device as
having been scheduled, and poll it, likely while the driver was dong something
requiring exclusive access. In the case above, its fairly clear that not having
the rings in a state ready to be polled will cause any number of crashes.
The fix should be pretty easy. netpoll uses its own bit to indicate that that
the napi instance is in a state of being serviced by netpoll (NAPI_STATE_NPSVC).
We can just gate disabling on that bit as well as the sched bit. That should
prevent netpoll from conducting a napi poll if we convert its set bit to a
test_and_set_bit operation to provide mutual exclusion
Change notes:
V2)
Remove a trailing whtiespace
Resubmit with proper subject prefix
V3)
Clean up spacing nits
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: jmaxwell@redhat.com
Tested-by: jmaxwell@redhat.com
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-23 14:32:50 -07:00
Revert "uart: pl011: Add support to ZTE ZX296702 uart"
2015-09-04 09:14:20 -07:00
bcma: switch GPIO portions to use GPIOLIB_IRQCHIP
2015-08-18 09:08:47 +03:00
ARM: SoC driver updates for v4.3
2015-09-01 13:00:04 -07:00
fsl /bestcomm
Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
2015-09-04 15:49:32 -07:00
ARM:
2015-09-10 16:42:49 -07:00
sound updates for 4.3-rc1
2015-09-04 11:46:02 -07:00
Changes for 4.3
2015-09-09 08:33:31 -07:00
Changes for 4.3
2015-09-09 08:33:31 -07:00
mmc: block: skip trim for some kingston eMMCs
2015-08-27 14:50:52 +02:00
netfilter: nf_conntrack: make nf_ct_zone_dflt built-in
2015-09-02 16:32:56 -07:00
MMC core:
2015-09-08 16:33:16 -07:00
Merge remote-tracking branches 'regulator/topic/qcom-smd', 'regulator/topic/qcom-spmi', 'regulator/topic/rk808', 'regulator/topic/stub' and 'regulator/topic/tol' into regulator-next
2015-08-30 14:40:11 +01:00
ARM: SoC driver updates for v4.3
2015-09-01 13:00:04 -07:00
Changes for 4.3
2015-09-09 08:33:31 -07:00
Revert "usb: interface authorization: Introduces the default interface authorization"
2015-08-18 09:58:45 -07:00
Merge branches 'acpi-pci', 'acpi-soc', 'acpi-ec' and 'acpi-osl'
2015-09-01 03:41:19 +02:00
average: remove out-of-line implementation
2015-08-20 14:10:23 -07:00
blkcg: rename subsystem name from blkio to io
2015-08-18 15:49:18 -07:00
block: Replace SG_GAPS with new queue limits mask
2015-08-19 14:26:02 -07:00
blkcg: use CGROUP_WEIGHT_* scale for io.weight on the unified hierarchy
2015-08-18 15:49:36 -07:00
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
2015-09-03 12:28:30 -07:00
libnvdimm for 4.3:
2015-09-08 14:35:59 -07:00
Merge branch 'for-4.3-unified-base' into for-4.3
2015-08-25 14:19:29 -04:00
Merge branch 'for-4.3-unified-base' into for-4.3
2015-08-25 14:19:29 -04:00
Merge branch 'for-4.3/blkcg' of git://git.kernel.dk/linux-block
2015-09-10 18:56:14 -07:00
clk: Constify clk_hw argument to provider APIs
2015-08-24 16:49:11 -07:00
Merge branch 'pm-opp'
2015-09-01 15:52:41 +02:00
cpuidle/coupled: Remove cpuidle_device::safe_state_index
2015-08-28 15:14:54 +02:00
capabilities: ambient capabilities
2015-09-04 16:54:41 -07:00
crypto: aead - Remove CRYPTO_ALG_AEAD_NEW flag
2015-08-17 16:53:53 +08:00
dax: add huge page fault support
2015-09-08 15:35:28 -07:00
block: kill merge_bvec_fn() completely
2015-08-13 12:31:57 -06:00
Power management and ACPI material for v4.3-rc1
2015-09-01 19:45:46 -07:00
dmaengine: Stricter legacy checking in dma_request_slave_channel_compat()
2015-08-20 12:01:03 +05:30
mm: add dma_pool_zalloc() call to DMA API
2015-09-08 15:35:28 -07:00
net: fix endian check warning in etherdevice.h
2015-08-17 12:14:53 -07:00
f2fs: add annotation for space utilization of regular/inline dentry
2015-08-21 22:45:13 -07:00
fbdev: fix cea_modes array size
2015-08-20 10:20:11 +03:00
dax: move DAX-related functions to a new header
2015-09-08 15:35:28 -07:00
drivers: usb: fsl: Workaround for USB erratum-A005275
2015-08-14 16:50:36 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2015-09-05 20:34:28 -07:00
genalloc: add support of multiple gen_pools per device
2015-09-04 16:54:41 -07:00
mm: use numa_mem_id() in alloc_pages_node()
2015-09-08 15:35:28 -07:00
dax: don't use set_huge_zero_page()
2015-09-08 15:35:28 -07:00
hugetlbfs: add hugetlbfs_fallocate()
2015-09-08 15:35:28 -07:00
i2c: core: Add support for best effort block read emulation
2015-08-24 14:05:19 +02:00
mac80211: fix BIT position for TDLS WIDE extended cap
2015-08-14 17:49:53 +02:00
IGMP: Inhibit reports for local multicast groups
2015-08-28 13:28:47 -07:00
add devm_memremap_pages
2015-08-27 19:40:58 -04:00
ipmi: Don't flush messages in sender() in run-to-completion mode
2015-09-03 15:02:28 -05:00
net: ipv6 sysctl option to ignore routes when nexthop link is down
2015-08-13 21:27:19 -07:00
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-09-01 14:33:35 -07:00
Pretty much all bug fixes and clean ups for 4.3, after a lot of
2015-09-03 12:52:19 -07:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-09-01 14:04:50 -07:00
x86/kasan, mm: Introduce generic kasan_populate_zero_shadow()
2015-08-22 14:54:55 +02:00
kernfs: implement kernfs_path_len()
2015-08-18 15:49:15 -07:00
kexec: split kexec_load syscall from kexec core code
2015-09-10 13:29:01 -07:00
kmod: use system_unbound_wq instead of khelper
2015-09-10 13:29:01 -07:00
kernel/kthread.c:kthread_create_on_node(): clarify documentation
2015-09-04 16:54:41 -07:00
KVM: make halt_poll_ns per-vCPU
2015-09-06 16:27:10 +02:00
libnvdimm, pmem: direct map legacy pmem by default
2015-08-28 23:40:05 -04:00
inode: add hlist_fake to avoid the inode hash lock in evict
2015-08-17 18:39:45 -04:00
mem-hotplug: handle node hole when initializing numa_meminfo.
2015-09-08 15:35:28 -07:00
memcg: zap try_get_mem_cgroup_from_page
2015-09-10 13:29:01 -07:00
mm: ZONE_DEVICE for "device memory"
2015-08-27 19:40:58 -04:00
add microchip LAN88xx phy driver
2015-09-09 17:19:14 -07:00
mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff()
2015-09-10 13:29:01 -07:00
mm: drop __nocast from vm_flags_t definition
2015-09-08 15:35:28 -07:00
mm: introduce idle page tracking
2015-09-10 13:29:01 -07:00
libnvdimm for 4.3:
2015-09-08 14:35:59 -07:00
netpoll: Close race condition between poll_one_napi and napi_disable
2015-09-23 14:32:50 -07:00
netfilter: nf_conntrack: make nf_ct_zone_dflt built-in
2015-09-02 16:32:56 -07:00
netfilter: Define v6ops in !CONFIG_NETFILTER case.
2015-08-27 16:35:51 -07:00
netlink, mmap: fix edge-case leakages in nf queue zero-copy
2015-09-09 21:43:22 -07:00
pnfs: move common blocklayout XDR defintions to nfs4.h
2015-08-17 13:22:49 -05:00
NFS: Remove nfs_release()
2015-08-17 13:32:56 -05:00
NFS: Get suppattr_exclcreat when getting server capabilities
2015-08-27 19:45:27 -04:00
NFSv4: Express delegation limit in units of pages
2015-09-07 12:36:13 -04:00
Merge branch 'nmi' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
2015-09-08 12:28:10 -07:00
NVMe: Add nvme subsystem reset IOCTL
2015-08-18 11:56:13 -06:00
device property: check fwnode type in to_of_node()
2015-08-26 01:46:39 +02:00
of/platform: add function to populate default bus
2015-08-25 11:29:55 -05:00
PKCS#7: Add OIDs for sha224, sha284 and sha512 hash algos and use them
2015-09-01 09:59:20 +10:00
mm, oom: add description of struct oom_control
2015-09-08 15:35:28 -07:00
mm: introduce idle page tracking
2015-09-10 13:29:01 -07:00
mm, page_isolation: make set/unset_migratetype_isolate() file-local
2015-09-08 15:35:28 -07:00
mm: introduce idle page tracking
2015-09-10 13:29:01 -07:00
mm: introduce idle page tracking
2015-09-10 13:29:01 -07:00
PCI: Move ATS declarations to linux/pci.h so they're all together
2015-08-13 15:59:58 -05:00
pci: mm: add pci_pool_zalloc() call
2015-09-08 15:35:28 -07:00
[media] tw68: Move PCI vendor and device IDs to pci_ids.h
2015-08-16 13:26:01 -03:00
percpu-rwsem: introduce percpu_rwsem_release() and percpu_rwsem_acquire()
2015-08-15 13:52:10 +02:00
net: phy: Allow PHY devices to identify themselves as Ethernet switches, etc.
2015-08-31 14:48:01 -07:00
phy: fixed_phy: Add gpio to determine link up/down.
2015-08-31 14:48:02 -07:00
PM / Domains: Remove unusable governor dummies
2015-08-29 01:54:43 +02:00
x86, pmem: clarify that ARCH_HAS_PMEM_API implies PMEM mapped WB
2015-08-27 19:40:59 -04:00
include/linux/poison.h: remove not-used poison pointer macros
2015-09-10 13:29:01 -07:00
hexdump: do not print debug dumps for !CONFIG_DEBUG
2015-09-10 13:29:01 -07:00
Add a matching set of device_ functions for determining mac/phy
2015-08-13 16:58:29 -07:00
pwm: Clean up kerneldoc
2015-08-17 15:40:20 +02:00
Merge remote-tracking branches 'regmap/topic/lockdep' and 'regmap/topic/seq-delay' into regmap-next
2015-09-04 17:22:10 +01:00
reset: Add (devm_)reset_control_get stub functions
2015-09-01 09:56:58 +02:00
mm: send one IPI per CPU to TLB flush all entries after unmapping pages
2015-09-04 16:54:41 -07:00
lib: scatterlist: add sg splitting function
2015-08-24 14:28:01 -06:00
mm: defer flush of writable TLB entries
2015-09-04 16:54:41 -07:00
seq_file: provide an analogue of print_hex_dump()
2015-09-10 13:29:01 -07:00
netfilter: bridge: fix routing of bridge frames with call-iptables=1
2015-09-14 18:08:33 +02:00
slab: infrastructure for bulk object allocation and freeing
2015-09-04 16:54:41 -07:00
smpboot: allow passing the cpumask on per-cpu thread registration
2015-09-04 16:54:41 -07:00
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-09-01 08:40:25 -07:00
lib/string_helpers: rename "esc" arg to "only"
2015-09-10 13:29:01 -07:00
mm: swap: zswap: maybe_preload & refactoring
2015-09-08 15:35:28 -07:00
mm/hwpoison: fix race between soft_offline_page and unpoison_memory
2015-09-08 15:35:28 -07:00
userfaultfd: activate syscall
2015-09-04 16:54:41 -07:00
time: Introduce struct itimerspec64
2015-08-17 11:25:28 -07:00
Merge branch 'fortglx/4.3/time' of https://git.linaro.org/people/john.stultz/linux into timers/core
2015-08-20 21:13:22 +02:00
lib: introduce strncpy_from_unsafe()
2015-08-28 16:27:27 -07:00
Revert "usb: interface authorization: Declare authorized attribute"
2015-08-18 09:59:12 -07:00
userfaultfd: mcopy_atomic|mfill_zeropage: UFFDIO_COPY|UFFDIO_ZEROPAGE preparation
2015-09-04 16:54:41 -07:00
userfaultfd: waitqueue: add nr wake parameter to __wake_up_locked_key
2015-09-04 16:54:41 -07:00
kernel/watchdog: move NMI function header declarations from watchdog.h to nmi.h
2015-09-04 16:54:41 -07:00
workqueue: fix some docbook warnings
2015-08-17 15:48:24 -04:00
mm: zbud: constify the zbud_ops
2015-09-08 15:35:28 -07:00
zpool: add zpool_has_pool()
2015-09-10 13:29:01 -07:00
zsmalloc: account the number of compacted pages
2015-09-08 15:35:28 -07:00
