/* * IEEE 802.15.4 interface for userspace * * Copyright 2007, 2008 Siemens AG * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation. * * This program 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. * * Written by: * Sergey Lapin * Dmitry Eremin-Solenikov */ #ifndef _AF_IEEE802154_H #define _AF_IEEE802154_H #include /* for sa_family_t */ enum { IEEE802154_ADDR_NONE = 0x0, /* RESERVED = 0x01, */ IEEE802154_ADDR_SHORT = 0x2, /* 16-bit address + PANid */ IEEE802154_ADDR_LONG = 0x3, /* 64-bit address + PANid */ }; /* address length, octets */ #define IEEE802154_ADDR_LEN 8 struct ieee802154_addr_sa { int addr_type; u16 pan_id; union { u8 hwaddr[IEEE802154_ADDR_LEN]; u16 short_addr; }; }; #define IEEE802154_PANID_BROADCAST 0xffff #define IEEE802154_ADDR_BROADCAST 0xffff #define IEEE802154_ADDR_UNDEF 0xfffe struct sockaddr_ieee802154 { sa_family_t family; /* AF_IEEE802154 */ struct ieee802154_addr_sa addr; }; /* get/setsockopt */ #define SOL_IEEE802154 0 #define WPAN_WANTACK 0 #define WPAN_SECURITY 1 #define WPAN_SECURITY_LEVEL 2 #define WPAN_SECURITY_DEFAULT 0 #define WPAN_SECURITY_OFF 1 #define WPAN_SECURITY_ON 2 #define WPAN_SECURITY_LEVEL_DEFAULT (-1) #endif next.git/'>summaryrefslogtreecommitdiff
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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/xen/arm/hypercall.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/xen/arm/hypercall.h')