| Message ID | 20181106033348.27361-1-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | dma: coh901318: Fix a double-lock bug | expand |
On Tue, Nov 6, 2018 at 4:33 AM Jia-Ju Bai <baijiaju1990@gmail.com> wrote: > The function coh901318_alloc_chan_resources() calls spin_lock_irqsave() > before calling coh901318_config(). > But coh901318_config() calls spin_lock_irqsave() again in its > definition, which may cause a double-lock bug. > > Because coh901318_config() is only called by > coh901318_alloc_chan_resources(), the bug fix is to remove the > calls to spin-lock and -unlock functions in coh901318_config(). > > Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Yours, Linus Walleij
On 06-11-18, 11:33, Jia-Ju Bai wrote: > The function coh901318_alloc_chan_resources() calls spin_lock_irqsave() > before calling coh901318_config(). > But coh901318_config() calls spin_lock_irqsave() again in its > definition, which may cause a double-lock bug. > > Because coh901318_config() is only called by > coh901318_alloc_chan_resources(), the bug fix is to remove the > calls to spin-lock and -unlock functions in coh901318_config(). Applied after fixing subsystem tag, thanks
diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c index eebaba3d9e78..fd862a478738 100644 --- a/drivers/dma/coh901318.c +++ b/drivers/dma/coh901318.c @@ -1807,8 +1807,6 @@ static int coh901318_config(struct coh901318_chan *cohc, int channel = cohc->id; void __iomem *virtbase = cohc->base->virtbase; - spin_lock_irqsave(&cohc->lock, flags); - if (param) p = param; else @@ -1828,8 +1826,6 @@ static int coh901318_config(struct coh901318_chan *cohc, coh901318_set_conf(cohc, p->config); coh901318_set_ctrl(cohc, p->ctrl_lli_last); - spin_unlock_irqrestore(&cohc->lock, flags); - return 0; }
The function coh901318_alloc_chan_resources() calls spin_lock_irqsave() before calling coh901318_config(). But coh901318_config() calls spin_lock_irqsave() again in its definition, which may cause a double-lock bug. Because coh901318_config() is only called by coh901318_alloc_chan_resources(), the bug fix is to remove the calls to spin-lock and -unlock functions in coh901318_config(). Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- drivers/dma/coh901318.c | 4 ---- 1 file changed, 4 deletions(-)