/** * \file drm_sarea.h * \brief SAREA definitions * * \author Michel Dänzer */ /* * Copyright 2002 Tungsten Graphics, Inc., Cedar Park, Texas. * All Rights Reserved. * * 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 (including the next * paragraph) 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 * TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS 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 _DRM_SAREA_H_ #define _DRM_SAREA_H_ #include "drm.h" #if defined(__cplusplus) extern "C" { #endif /* SAREA area needs to be at least a page */ #if defined(__alpha__) #define SAREA_MAX 0x2000U #elif defined(__mips__) #define SAREA_MAX 0x4000U #elif defined(__ia64__) #define SAREA_MAX 0x10000U /* 64kB */ #else /* Intel 830M driver needs at least 8k SAREA */ #define SAREA_MAX 0x2000U #endif /** Maximum number of drawables in the SAREA */ #define SAREA_MAX_DRAWABLES 256 #define SAREA_DRAWABLE_CLAIMED_ENTRY 0x80000000 /** SAREA drawable */ struct drm_sarea_drawable { unsigned int stamp; unsigned int flags; }; /** SAREA frame */ struct drm_sarea_frame { unsigned int x; unsigned int y; unsigned int width; unsigned int height; unsigned int fullscreen; }; /** SAREA */ struct drm_sarea { /** first thing is always the DRM locking structure */ struct drm_hw_lock lock; /** \todo Use readers/writer lock for drm_sarea::drawable_lock */ struct drm_hw_lock drawable_lock; struct drm_sarea_drawable drawableTable[SAREA_MAX_DRAWABLES]; /**< drawables */ struct drm_sarea_frame frame; /**< frame */ drm_context_t dummy_context; }; #ifndef __KERNEL__ typedef struct drm_sarea_drawable drm_sarea_drawable_t; typedef struct drm_sarea_frame drm_sarea_frame_t; typedef struct drm_sarea drm_sarea_t; #endif #if defined(__cplusplus) } #endif #endif /* _DRM_SAREA_H_ */ /form>
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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 /net/dccp/output.c
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 'net/dccp/output.c')