Messages in this thread | | | Date | Fri, 20 Feb 2015 19:26:59 +0100 | From | Jan Yenya Kasprzak <> | Subject | Re: [PATCH 6/7 linux-next] wan: cosa: replace current->state by set_current_state() |
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Fabian Frederick wrote: : Use helper functions to access current->state. : Direct assignments are prone to races and therefore buggy. : : current->state = TASK_RUNNING is replaced by __set_current_state() : : Thanks to Peter Zijlstra for the exact definition of the problem.
OK, thanks. Although I wonder whether real users of COSA (an ISA-based WAN card) do exist.
Acked-By: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
-Y.
: : Suggested-By: Peter Zijlstra <peterz@infradead.org> : Signed-off-by: Fabian Frederick <fabf@skynet.be> : --- : drivers/net/wan/cosa.c | 12 ++++++------ : 1 file changed, 6 insertions(+), 6 deletions(-) : : diff --git a/drivers/net/wan/cosa.c b/drivers/net/wan/cosa.c : index 83c39e2..88d121d 100644 : --- a/drivers/net/wan/cosa.c : +++ b/drivers/net/wan/cosa.c : @@ -806,21 +806,21 @@ static ssize_t cosa_read(struct file *file, : spin_lock_irqsave(&cosa->lock, flags); : add_wait_queue(&chan->rxwaitq, &wait); : while (!chan->rx_status) { : - current->state = TASK_INTERRUPTIBLE; : + set_current_state(TASK_INTERRUPTIBLE); : spin_unlock_irqrestore(&cosa->lock, flags); : schedule(); : spin_lock_irqsave(&cosa->lock, flags); : if (signal_pending(current) && chan->rx_status == 0) { : chan->rx_status = 1; : remove_wait_queue(&chan->rxwaitq, &wait); : - current->state = TASK_RUNNING; : + __set_current_state(TASK_RUNNING); : spin_unlock_irqrestore(&cosa->lock, flags); : mutex_unlock(&chan->rlock); : return -ERESTARTSYS; : } : } : remove_wait_queue(&chan->rxwaitq, &wait); : - current->state = TASK_RUNNING; : + __set_current_state(TASK_RUNNING); : kbuf = chan->rxdata; : count = chan->rxsize; : spin_unlock_irqrestore(&cosa->lock, flags); : @@ -890,14 +890,14 @@ static ssize_t cosa_write(struct file *file, : spin_lock_irqsave(&cosa->lock, flags); : add_wait_queue(&chan->txwaitq, &wait); : while (!chan->tx_status) { : - current->state = TASK_INTERRUPTIBLE; : + set_current_state(TASK_INTERRUPTIBLE); : spin_unlock_irqrestore(&cosa->lock, flags); : schedule(); : spin_lock_irqsave(&cosa->lock, flags); : if (signal_pending(current) && chan->tx_status == 0) { : chan->tx_status = 1; : remove_wait_queue(&chan->txwaitq, &wait); : - current->state = TASK_RUNNING; : + __set_current_state(TASK_RUNNING); : chan->tx_status = 1; : spin_unlock_irqrestore(&cosa->lock, flags); : up(&chan->wsem); : @@ -905,7 +905,7 @@ static ssize_t cosa_write(struct file *file, : } : } : remove_wait_queue(&chan->txwaitq, &wait); : - current->state = TASK_RUNNING; : + __set_current_state(TASK_RUNNING); : up(&chan->wsem); : spin_unlock_irqrestore(&cosa->lock, flags); : kfree(kbuf); : -- : 2.1.0
-- | Jan "Yenya" Kasprzak <kas at {fi.muni.cz - work | yenya.net - private}> | | New GPG 4096R/A45477D5 -- see http://www.fi.muni.cz/~kas/pgp-rollover.txt | | http://www.fi.muni.cz/~kas/ Journal: http://www.fi.muni.cz/~kas/blog/ | ||| "New and improved" is only really improved if it also takes backwards ||| ||| compatibility into account, rather than saying "now everybody must do ||| ||| things the new and improved - and different - way" --Linus Torvalds |||
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