/* * Copyright (C) 2016 Maxime Ripard * * This file is dual-licensed: you can use it either under the terms * of the GPL or the X11 license, at your option. Note that this dual * licensing only applies to this file, and not this project as a * whole. * * a) This file is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This file is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * Or, alternatively, * * b) Permission is hereby granted, free of charge, to any person * obtaining a copy of this software and associated documentation * files (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, * copy, modify, merge, publish, distribute, sublicense, and/or * sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following * conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ #ifndef _DT_BINDINGS_RST_SUN8I_A23_A33_H_ #define _DT_BINDINGS_RST_SUN8I_A23_A33_H_ #define RST_USB_PHY0 0 #define RST_USB_PHY1 1 #define RST_USB_HSIC 2 #define RST_MBUS 3 #define RST_BUS_MIPI_DSI 4 #define RST_BUS_SS 5 #define RST_BUS_DMA 6 #define RST_BUS_MMC0 7 #define RST_BUS_MMC1 8 #define RST_BUS_MMC2 9 #define RST_BUS_NAND 10 #define RST_BUS_DRAM 11 #define RST_BUS_HSTIMER 12 #define RST_BUS_SPI0 13 #define RST_BUS_SPI1 14 #define RST_BUS_OTG 15 #define RST_BUS_EHCI 16 #define RST_BUS_OHCI 17 #define RST_BUS_VE 18 #define RST_BUS_LCD 19 #define RST_BUS_CSI 20 #define RST_BUS_DE_BE 21 #define RST_BUS_DE_FE 22 #define RST_BUS_GPU 23 #define RST_BUS_MSGBOX 24 #define RST_BUS_SPINLOCK 25 #define RST_BUS_DRC 26 #define RST_BUS_SAT 27 #define RST_BUS_LVDS 28 #define RST_BUS_CODEC 29 #define RST_BUS_I2S0 30 #define RST_BUS_I2S1 31 #define RST_BUS_I2C0 32 #define RST_BUS_I2C1 33 #define RST_BUS_I2C2 34 #define RST_BUS_UART0 35 #define RST_BUS_UART1 36 #define RST_BUS_UART2 37 #define RST_BUS_UART3 38 #define RST_BUS_UART4 39 #endif /* _DT_BINDINGS_RST_SUN8I_A23_A33_H_ */ nts/xen.h
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authorDouglas Miller <dougmill@linux.vnet.ibm.com>2017-01-28 06:42:20 -0600
committerTejun Heo <tj@kernel.org>2017-01-28 07:49:42 -0500
commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch)
tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /include/trace/events/xen.h
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 'include/trace/events/xen.h')