On Thu, Nov 28, 2019 at 08:18:30AM +0000, Anton Ivanov wrote:
>
>
> On 28/11/2019 08:06, Dan Carpenter wrote:
> > On Thu, Nov 28, 2019 at 02:01:47AM +0000, Wei Yongjun wrote:
> > > A spin lock is taken here so we should use GFP_ATOMIC.
> > >
> > > Fixes: 9807019a62dc ("um: Loadable BPF "Firmware" for vector drivers")
> > > Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
> > > ---
> > > arch/um/drivers/vector_kern.c | 4 ++--
> > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/arch/um/drivers/vector_kern.c b/arch/um/drivers/vector_kern.c
> > > index 92617e16829e..6ff0065a271d 100644
> > > --- a/arch/um/drivers/vector_kern.c
> > > +++ b/arch/um/drivers/vector_kern.c
> > > @@ -1402,7 +1402,7 @@ static int vector_net_load_bpf_flash(struct net_device *dev,
> > > kfree(vp->bpf->filter);
> > > vp->bpf->filter = NULL;
> > > } else {
> > > - vp->bpf = kmalloc(sizeof(struct sock_fprog), GFP_KERNEL);
> > > + vp->bpf = kmalloc(sizeof(struct sock_fprog), GFP_ATOMIC);
> > > if (vp->bpf == NULL) {
> > > netdev_err(dev, "failed to allocate memory for firmware\n");
> > > goto flash_fail;
> > > @@ -1414,7 +1414,7 @@ static int vector_net_load_bpf_flash(struct net_device *dev,
> > > if (request_firmware(&fw, efl->data, &vdevice->pdev.dev))
> > ^^^^^^^^^^^^^^^^
> >
> > Is it really possible to call request_firmware() while holding a
> > spin_lock? I was so sure that read from the disk.
>
> Works, I tested the patch quite a few times.
>
Do you have CONFIG_DEBUG_ATOMIC_SLEEP enabled? The GFP_KERNEL calls
should have triggered a warning if so.
regards,
dan carpenter
