/** * Copyright (C) 2008, Creative Technology Ltd. All Rights Reserved. * * This source file is released under GPL v2 license (no other versions). * See the COPYING file included in the main directory of this source * distribution for the license terms and conditions. * * @File ctvmem.h * * @Brief * This file contains the definition of virtual memory management object * for card device. * * @Author Liu Chun * @Date Mar 28 2008 */ #ifndef CTVMEM_H #define CTVMEM_H #define CT_PTP_NUM 4 /* num of device page table pages */ #include #include #include #include /* The chip can handle the page table of 4k pages * (emu20k1 can handle even 8k pages, but we don't use it right now) */ #define CT_PAGE_SIZE 4096 #define CT_PAGE_SHIFT 12 #define CT_PAGE_MASK (~(PAGE_SIZE - 1)) #define CT_PAGE_ALIGN(addr) ALIGN(addr, CT_PAGE_SIZE) struct ct_vm_block { unsigned int addr; /* starting logical addr of this block */ unsigned int size; /* size of this device virtual mem block */ struct list_head list; }; struct snd_pcm_substream; /* Virtual memory management object for card device */ struct ct_vm { struct snd_dma_buffer ptp[CT_PTP_NUM]; /* Device page table pages */ unsigned int size; /* Available addr space in bytes */ struct list_head unused; /* List of unused blocks */ struct list_head used; /* List of used blocks */ struct mutex lock; /* Map host addr (kmalloced/vmalloced) to device logical addr. */ struct ct_vm_block *(*map)(struct ct_vm *, struct snd_pcm_substream *, int size); /* Unmap device logical addr area. */ void (*unmap)(struct ct_vm *, struct ct_vm_block *block); dma_addr_t (*get_ptp_phys)(struct ct_vm *vm, int index); }; int ct_vm_create(struct ct_vm **rvm, struct pci_dev *pci); void ct_vm_destroy(struct ct_vm *vm); #endif /* CTVMEM_H */ eef542c5414e54bf1a'>treecommitdiff
path: root/drivers/usb/gadget/udc/renesas_usb3.c
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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 /drivers/usb/gadget/udc/renesas_usb3.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 'drivers/usb/gadget/udc/renesas_usb3.c')