/********************************************************************* * * Filename: ircomm_tty.h * Version: * Description: * Status: Experimental. * Author: Dag Brattli * Created at: Sun Jun 6 23:24:22 1999 * Modified at: Fri Jan 28 13:16:57 2000 * Modified by: Dag Brattli * * Copyright (c) 1999-2000 Dag Brattli, All Rights Reserved. * * 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. * * This program 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 this program; if not, see . * ********************************************************************/ #ifndef IRCOMM_TTY_H #define IRCOMM_TTY_H #include #include #include #include /* struct tty_struct */ #include #include #include #define IRCOMM_TTY_PORTS 32 #define IRCOMM_TTY_MAGIC 0x3432 #define IRCOMM_TTY_MAJOR 161 #define IRCOMM_TTY_MINOR 0 /* This is used as an initial value to max_header_size before the proper * value is filled in (5 for ttp, 4 for lmp). This allow us to detect * the state of the underlying connection. - Jean II */ #define IRCOMM_TTY_HDR_UNINITIALISED 16 /* Same for payload size. See qos.c for the smallest max data size */ #define IRCOMM_TTY_DATA_UNINITIALISED (64 - IRCOMM_TTY_HDR_UNINITIALISED) /* * IrCOMM TTY driver state */ struct ircomm_tty_cb { irda_queue_t queue; /* Must be first */ struct tty_port port; magic_t magic; int state; /* Connect state */ struct ircomm_cb *ircomm; /* IrCOMM layer instance */ struct sk_buff *tx_skb; /* Transmit buffer */ struct sk_buff *ctrl_skb; /* Control data buffer */ /* Parameters */ struct ircomm_params settings; __u8 service_type; /* The service that we support */ int client; /* True if we are a client */ LOCAL_FLOW flow; /* IrTTP flow status */ int line; __u8 dlsap_sel; __u8 slsap_sel; __u32 saddr; __u32 daddr; __u32 max_data_size; /* Max data we can transmit in one packet */ __u32 max_header_size; /* The amount of header space we must reserve */ __u32 tx_data_size; /* Max data size of current tx_skb */ struct iriap_cb *iriap; /* Instance used for querying remote IAS */ struct ias_object* obj; void *skey; void *ckey; struct timer_list watchdog_timer; struct work_struct tqueue; /* Protect concurent access to : * o self->ctrl_skb * o self->tx_skb * Maybe other things may gain to be protected as well... * Jean II */ spinlock_t spinlock; }; void ircomm_tty_start(struct tty_struct *tty); void ircomm_tty_check_modem_status(struct ircomm_tty_cb *self); int ircomm_tty_tiocmget(struct tty_struct *tty); int ircomm_tty_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear); int ircomm_tty_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg); void ircomm_tty_set_termios(struct tty_struct *tty, struct ktermios *old_termios); #endif ion>space:mode:
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
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')