/* * Copyright 2015, Cyril Bur, IBM Corp. * * This program 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. */ #include "basic_asm.h" #include "vsx_asm.h" #long check_vsx(vector int *r3); #This function wraps storeing VSX regs to the end of an array and a #call to a comparison function in C which boils down to a memcmp() FUNC_START(check_vsx) PUSH_BASIC_STACK(32) std r3,STACK_FRAME_PARAM(0)(sp) addi r3, r3, 16 * 12 #Second half of array bl store_vsx ld r3,STACK_FRAME_PARAM(0)(sp) bl vsx_memcmp POP_BASIC_STACK(32) blr FUNC_END(check_vsx) # int preempt_vmx(vector int *varray, int *threads_starting, # int *running); # On starting will (atomically) decrement threads_starting as a signal # that the VMX have been loaded with varray. Will proceed to check the # validity of the VMX registers while running is not zero. FUNC_START(preempt_vsx) PUSH_BASIC_STACK(512) std r3,STACK_FRAME_PARAM(0)(sp) # vector int *varray std r4,STACK_FRAME_PARAM(1)(sp) # int *threads_starting std r5,STACK_FRAME_PARAM(2)(sp) # int *running bl load_vsx nop sync # Atomic DEC ld r3,STACK_FRAME_PARAM(1)(sp) 1: lwarx r4,0,r3 addi r4,r4,-1 stwcx. r4,0,r3 bne- 1b 2: ld r3,STACK_FRAME_PARAM(0)(sp) bl check_vsx nop cmpdi r3,0 bne 3f ld r4,STACK_FRAME_PARAM(2)(sp) ld r5,0(r4) cmpwi r5,0 bne 2b 3: POP_BASIC_STACK(512) blr FUNC_END(preempt_vsx) ux/net-next.git/?h=nds-private-remove'>summaryrefslogtreecommitdiff
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authorIago Abal <mail@iagoabal.eu>2017-01-11 14:00:21 +0100
committerVinod Koul <vinod.koul@intel.com>2017-01-25 15:35:11 +0530
commit91539eb1fda2d530d3b268eef542c5414e54bf1a (patch)
tree960f5ca6342ad20837aff18aad6e8ecd7da32fd6 /sound/soc/codecs/wm8996.h
parent6610d0edf6dc7ee97e46ab3a538a565c79d26199 (diff)
dmaengine: pl330: fix double lock
The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the following double-lock bug: Double lock: 1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236; 2. call to function `pl330_release_channel' immediately after; 3. call to function `dma_pl330_rqcb' in line 1753; 4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505. I have fixed it as suggested by Marek Szyprowski. First, I have replaced `pch->lock' with `pl330->lock' in functions `pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids the double-lock by acquiring a different lock than `dma_pl330_rqcb'. NOTE that, as a result, `pl330_free_chan_resources' executes `list_splice_tail_init' on `pch->work_list' under lock `pl330->lock', whereas in the rest of the code `pch->work_list' is protected by `pch->lock'. I don't know if this may cause race conditions. Similarly `pch->cyclic' is written by `pl330_alloc_chan_resources' under `pl330->lock' but read by `pl330_tx_submit' under `pch->lock'. Second, I have removed locking from `pl330_request_channel' and `pl330_release_channel' functions. Function `pl330_request_channel' is only called from `pl330_alloc_chan_resources', so the lock is already held. Function `pl330_release_channel' is called from `pl330_free_chan_resources', which already holds the lock, and from `pl330_del'. Function `pl330_del' is called in an error path of `pl330_probe' and at the end of `pl330_remove', but I assume that there cannot be concurrent accesses to the protected data at those points. Signed-off-by: Iago Abal <mail@iagoabal.eu> Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'sound/soc/codecs/wm8996.h')