Hi,
> Noralf Trønnes <noralf@xxxxxxxxxxx> hat am 18. Februar 2017 um 19:34 geschrieben:
>
>
>
> Den 16.02.2017 22.20, skrev Stefan Wahren:
> > Since commit e2474541032d ("bcm2835: Fix hang for writing messages
> > larger than 16 bytes") the interrupt handler is prone to a possible
> > NULL pointer dereference. This could happen if an interrupt fires
> > before curr_msg is set by bcm2835_i2c_xfer_msg() and randomly occurs
> > on the RPi 3. Even this is an unexpected behavior the driver must
> > handle that with an error instead of a crash.
> >
> > CC: Noralf Trønnes <noralf@xxxxxxxxxxx>
> > CC: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
> > Reported-by: Peter Robinson <pbrobinson@xxxxxxxxx>
> > Fixes: e2474541032d ("bcm2835: Fix hang for writing messages larger than 16 bytes")
> > Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
> > ---
> > drivers/i2c/busses/i2c-bcm2835.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c
> > index c3436f6..10e39c8 100644
> > --- a/drivers/i2c/busses/i2c-bcm2835.c
> > +++ b/drivers/i2c/busses/i2c-bcm2835.c
> > @@ -195,7 +195,9 @@ static irqreturn_t bcm2835_i2c_isr(int this_irq, void *data)
> > }
> >
> > if (val & BCM2835_I2C_S_DONE) {
> > - if (i2c_dev->curr_msg->flags & I2C_M_RD) {
> > + if (!i2c_dev->curr_msg) {
> > + dev_err(i2c_dev->dev, "Got unexpected interrupt (from firmware?)\n");
> > + } else if (i2c_dev->curr_msg->flags & I2C_M_RD) {
> > bcm2835_drain_rxfifo(i2c_dev);
> > val = bcm2835_i2c_readl(i2c_dev, BCM2835_I2C_S);
> > }
>
> Thanks,
>
> Acked-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
>
thanks, but i would be more happier to receive feedback for patches 2 and 3.
Stefan
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