/* * Copyright (C) 2005 Russell King. * Data taken from include/asm-i386/serial.h * * 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. */ #include #include #include #include "8250.h" #define SERIAL8250_FOURPORT(_base, _irq) \ SERIAL8250_PORT_FLAGS(_base, _irq, UPF_FOURPORT) static struct plat_serial8250_port fourport_data[] = { SERIAL8250_FOURPORT(0x1a0, 9), SERIAL8250_FOURPORT(0x1a8, 9), SERIAL8250_FOURPORT(0x1b0, 9), SERIAL8250_FOURPORT(0x1b8, 9), SERIAL8250_FOURPORT(0x2a0, 5), SERIAL8250_FOURPORT(0x2a8, 5), SERIAL8250_FOURPORT(0x2b0, 5), SERIAL8250_FOURPORT(0x2b8, 5), { }, }; static struct platform_device fourport_device = { .name = "serial8250", .id = PLAT8250_DEV_FOURPORT, .dev = { .platform_data = fourport_data, }, }; static int __init fourport_init(void) { return platform_device_register(&fourport_device); } module_init(fourport_init); MODULE_AUTHOR("Russell King"); MODULE_DESCRIPTION("8250 serial probe module for AST Fourport cards"); MODULE_LICENSE("GPL"); vate-remove net-next plumbingsTobias Klauser
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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 /kernel/trace/bpf_trace.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 'kernel/trace/bpf_trace.c')