Re: [PATCH] hw/pci/pci.c: Assert that pci_irq_handler() inputs are valid

[Philippe Mathieu-Daudé]

On 3/23/21 5:46 PM, Peter Maydell wrote:
> pci_irq_handler documents that it must be called with 0 <= irq_num <=
> 3 and level either 0 or 1.  Add assertions that the caller has passed
> us in valid arguments.
> 
> In particular, if a device model fails to set the PCI_INTERRUPT_PIN
> field in its config space correctly to indicate that it has an
> interrupt, and then tries to raise an interrupt (either by calling
> pci_set_irq(), or by getting a qemu_irq from pci_allocate_irq() and
> then calling qemu_set_irq() on that) we will now diagnose this device
> model bug with an assertion rather than engaging in the undefined
> behaviour of shifting by a negative number.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  hw/pci/pci.c | 3 +++
>  1 file changed, 3 insertions(+)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>