Re: [patch V2 29/31] genirq/msi: Add abuse prevention comment to msi header

Greg Kroah-Hartman
2021-12-07T08:21:43Z

On Mon, Dec 06, 2021 at 11:51:49PM +0100, Thomas Gleixner wrote:
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
> include/linux/msi.h | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> --- a/include/linux/msi.h
> +++ b/include/linux/msi.h
> @@ -2,6 +2,20 @@
> #ifndef LINUX_MSI_H
> #define LINUX_MSI_H
>
> +/*
> + * This header file contains MSI data structures and functions which are
> + * only relevant for:
> + * - Interrupt core code
> + * - PCI/MSI core code
> + * - MSI interrupt domain implementations
> + * - IOMMU, low level VFIO, NTB and other justified exceptions
> + * dealing with low level MSI details.
> + *
> + * Regular device drivers have no business with any of these functions and
> + * especially storing MSI descriptor pointers in random code is considered
> + * abuse. The only function which is relevant for drivers is msi_get_virq().
> + */
> +
> #include <linux/cpumask.h>
> #include <linux/mutex.h>
> #include <linux/list.h>
>

Ah, to be young and idealistic and hope that kernel developers read
comments in header files :)

You might want to add this to the driver-api kernel doc build?

Anyway, looks good to me:

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>