diff options
| author | Alexey Khoroshilov <khoroshilov@ispras.ru> | 2013-04-13 23:52:04 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2013-04-22 15:08:30 +0200 |
| commit | 5ddfbbb9ca2e74d4b392ccef675641babba6b7f8 (patch) | |
| tree | 8e2be3b14c057112be5d5d9fb8a708df2f06cc1e /drivers/media/pci/cx88/cx88-mpeg.c | |
| parent | [media] solo6x10: Update the encoder mode on VIDIOC_S_FMT (diff) | |
| download | linux-5ddfbbb9ca2e74d4b392ccef675641babba6b7f8.tar.xz linux-5ddfbbb9ca2e74d4b392ccef675641babba6b7f8.zip | |
[media] cx88: Fix unsafe locking in suspend-resume
Legacy PCI suspend-resume handlers are called with interrupts enabled.
But cx8800_suspend/cx8800_resume and
cx8802_suspend_common/cx8802_resume_common use spin_lock/spin_unlock
functions to acquire dev->slock, while the same lock is acquired in the
corresponding irq-handlers: cx8800_irq and cx8802_irq.
That means a deadlock is possible if an interrupt happens while suspend
or resume owns the lock. The patch replaces spin_lock/spin_unlock with
spin_lock_irqsave/spin_unlock_irqrestore.
Found by Linux Driver Verification project (linuxtesting.org).
[mchehab@redhat.com: Fix CodingStyle]
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/pci/cx88/cx88-mpeg.c')
| -rw-r--r-- | drivers/media/pci/cx88/cx88-mpeg.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/media/pci/cx88/cx88-mpeg.c b/drivers/media/pci/cx88/cx88-mpeg.c index c9d3182f79d5..2d3507eb4897 100644 --- a/drivers/media/pci/cx88/cx88-mpeg.c +++ b/drivers/media/pci/cx88/cx88-mpeg.c @@ -532,16 +532,17 @@ static int cx8802_suspend_common(struct pci_dev *pci_dev, pm_message_t state) { struct cx8802_dev *dev = pci_get_drvdata(pci_dev); struct cx88_core *core = dev->core; + unsigned long flags; /* stop mpeg dma */ - spin_lock(&dev->slock); + spin_lock_irqsave(&dev->slock, flags); if (!list_empty(&dev->mpegq.active)) { dprintk( 2, "suspend\n" ); printk("%s: suspend mpeg\n", core->name); cx8802_stop_dma(dev); del_timer(&dev->mpegq.timeout); } - spin_unlock(&dev->slock); + spin_unlock_irqrestore(&dev->slock, flags); /* FIXME -- shutdown device */ cx88_shutdown(dev->core); @@ -558,6 +559,7 @@ static int cx8802_resume_common(struct pci_dev *pci_dev) { struct cx8802_dev *dev = pci_get_drvdata(pci_dev); struct cx88_core *core = dev->core; + unsigned long flags; int err; if (dev->state.disabled) { @@ -584,12 +586,12 @@ static int cx8802_resume_common(struct pci_dev *pci_dev) cx88_reset(dev->core); /* restart video+vbi capture */ - spin_lock(&dev->slock); + spin_lock_irqsave(&dev->slock, flags); if (!list_empty(&dev->mpegq.active)) { printk("%s: resume mpeg\n", core->name); cx8802_restart_queue(dev,&dev->mpegq); } - spin_unlock(&dev->slock); + spin_unlock_irqrestore(&dev->slock, flags); return 0; } |