From a1acdbc55403d94ac8dddcb0311360bc6dae659f Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Tue, 23 Feb 2021 14:30:52 +0000 Subject: staging: comedi: comedi_parport: Use 16-bit 0 for interrupt data The comedi_parport driver has an "interrupt" subdevice that supports Comedi asynchronous commands, placing a value in the Comedi buffer for each interrupt. The subdevice uses Comedi's 16-bit sample format but the interrupt handler is calling `comedi_buf_write_samples()` with the address of a 32-bit integer `&s->state`. On bigendian machines, this will copy 2 bytes from the wrong end of the 32-bit integer. This isn't really a problem since `s->state` will always be 0 for this subdevice, but clean it up by using a 16-bit variable initialized to 0 to pass the value. Signed-off-by: Ian Abbott Link: https://lore.kernel.org/r/20210223143055.257402-12-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/comedi_parport.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/staging/comedi') diff --git a/drivers/staging/comedi/drivers/comedi_parport.c b/drivers/staging/comedi/drivers/comedi_parport.c index 9361b2dcf949..5338b5eea440 100644 --- a/drivers/staging/comedi/drivers/comedi_parport.c +++ b/drivers/staging/comedi/drivers/comedi_parport.c @@ -210,12 +210,13 @@ static irqreturn_t parport_interrupt(int irq, void *d) struct comedi_device *dev = d; struct comedi_subdevice *s = dev->read_subdev; unsigned int ctrl; + unsigned short val = 0; ctrl = inb(dev->iobase + PARPORT_CTRL_REG); if (!(ctrl & PARPORT_CTRL_IRQ_ENA)) return IRQ_NONE; - comedi_buf_write_samples(s, &s->state, 1); + comedi_buf_write_samples(s, &val, 1); comedi_handle_events(dev, s); return IRQ_HANDLED; -- cgit v1.2.3