config USB_DWC2 tristate "DesignWare USB2 DRD Core Support" depends on HAS_DMA depends on USB || USB_GADGET depends on HAS_IOMEM help Say Y here if your system has a Dual Role Hi-Speed USB controller based on the DesignWare HSOTG IP Core. For host mode, if you choose to build the driver as dynamically linked modules, the core module will be called dwc2.ko, the PCI bus interface module (if you have a PCI bus system) will be called dwc2_pci.ko, and the platform interface module (for controllers directly connected to the CPU) will be called dwc2_platform.ko. For all modes(host, gadget and dual-role), there will be an additional module named dwc2.ko. if USB_DWC2 choice bool "DWC2 Mode Selection" default USB_DWC2_DUAL_ROLE if (USB && USB_GADGET) default USB_DWC2_HOST if (USB && !USB_GADGET) default USB_DWC2_PERIPHERAL if (!USB && USB_GADGET) config USB_DWC2_HOST bool "Host only mode" depends on USB=y || (USB_DWC2=m && USB) help The Designware USB2.0 high-speed host controller integrated into many SoCs. Select this option if you want the driver to operate in Host-only mode. comment "Gadget/Dual-role mode requires USB Gadget support to be enabled" config USB_DWC2_PERIPHERAL bool "Gadget only mode" depends on USB_GADGET=y || USB_GADGET=USB_DWC2 help The Designware USB2.0 high-speed gadget controller integrated into many SoCs. Select this option if you want the driver to operate in Peripheral-only mode. This option requires USB_GADGET to be enabled. config USB_DWC2_DUAL_ROLE bool "Dual Role mode" depends on (USB=y && USB_GADGET=y) || (USB_DWC2=m && USB && USB_GADGET) help Select this option if you want the driver to work in a dual-role mode. In this mode both host and gadget features are enabled, and the role will be determined by the cable that gets plugged-in. This option requires USB_GADGET to be enabled. endchoice config USB_DWC2_PCI tristate "DWC2 PCI" depends on PCI depends on USB_GADGET || !USB_GADGET default n select NOP_USB_XCEIV help The Designware USB2.0 PCI interface module for controllers connected to a PCI bus. config USB_DWC2_DEBUG bool "Enable Debugging Messages" help Say Y here to enable debugging messages in the DWC2 Driver. config USB_DWC2_VERBOSE bool "Enable Verbose Debugging Messages" depends on USB_DWC2_DEBUG help Say Y here to enable verbose debugging messages in the DWC2 Driver. WARNING: Enabling this will quickly fill your message log. If in doubt, say N. config USB_DWC2_TRACK_MISSED_SOFS bool "Enable Missed SOF Tracking" help Say Y here to enable logging of missed SOF events to the dmesg log. WARNING: This feature is still experimental. If in doubt, say N. config USB_DWC2_DEBUG_PERIODIC bool "Enable Debugging Messages For Periodic Transfers" depends on USB_DWC2_DEBUG || USB_DWC2_VERBOSE default y help Say N here to disable (verbose) debugging messages to be logged for periodic transfers. This allows better debugging of non-periodic transfers, but of course the debug logs will be incomplete. Note that this also disables some debug messages for which the transfer type cannot be deduced. endif 6c529ad3ce&id2=f2593cb1b29185d38db706cbcbe22ed538720ae1'>ipv4/ip_vti.c
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Diffstat (limited to 'net/ipv4/ip_vti.c')
' class='oid'>4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /net/wireless/ethtool.c
parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'net/wireless/ethtool.c')