/* SCTP kernel implementation * (C) Copyright IBM Corp. 2001, 2004 * Copyright (c) 1999-2000 Cisco, Inc. * Copyright (c) 1999-2001 Motorola, Inc. * Copyright (c) 2001 Intel Corp. * Copyright (c) 2001 Nokia, Inc. * Copyright (c) 2001 La Monte H.P. Yarroll * * These are the definitions needed for the sctp_ulpq type. The * sctp_ulpq is the interface between the Upper Layer Protocol, or ULP, * and the core SCTP state machine. This is the component which handles * reassembly and ordering. * * This SCTP implementation 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, or (at your option) * any later version. * * This SCTP implementation 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. * * You should have received a copy of the GNU General Public License * along with GNU CC; see the file COPYING. If not, see * . * * Please send any bug reports or fixes you make to the * email addresses: * lksctp developers * * Written or modified by: * Jon Grimm * La Monte H.P. Yarroll * Sridhar Samudrala */ #ifndef __sctp_ulpqueue_h__ #define __sctp_ulpqueue_h__ /* A structure to carry information to the ULP (e.g. Sockets API) */ struct sctp_ulpq { char pd_mode; struct sctp_association *asoc; struct sk_buff_head reasm; struct sk_buff_head lobby; }; /* Prototypes. */ struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *, struct sctp_association *); void sctp_ulpq_flush(struct sctp_ulpq *ulpq); void sctp_ulpq_free(struct sctp_ulpq *); /* Add a new DATA chunk for processing. */ int sctp_ulpq_tail_data(struct sctp_ulpq *, struct sctp_chunk *, gfp_t); /* Add a new event for propagation to the ULP. */ int sctp_ulpq_tail_event(struct sctp_ulpq *, struct sctp_ulpevent *ev); /* Renege previously received chunks. */ void sctp_ulpq_renege(struct sctp_ulpq *, struct sctp_chunk *, gfp_t); /* Perform partial delivery. */ void sctp_ulpq_partial_delivery(struct sctp_ulpq *, gfp_t); /* Abort the partial delivery. */ void sctp_ulpq_abort_pd(struct sctp_ulpq *, gfp_t); /* Clear the partial data delivery condition on this socket. */ int sctp_clear_pd(struct sock *sk, struct sctp_association *asoc); /* Skip over an SSN. */ void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn); void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *, __u32); #endif /* __sctp_ulpqueue_h__ */ /net-next.git/commit/include?id=966d2b04e070bc040319aaebfec09e0144dc3341'>include/dt-bindings/dma
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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/dt-bindings/dma
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/dt-bindings/dma')