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    SubjectRe: [PATCH 2/2] msi: Add sanity check if more than MAX_DEV_MSIS MSIs are requested
    On Thu, Jun 09, 2022 at 05:38:43PM +0200, Julian Vetter wrote:
    > If a device requests more than MAX_DEV_MSIS the MSI index will collide with
    > the devid and might cause Linux to compute twice the same virtual interrupt
    > number for two different devices.
    >
    > Signed-off-by: Julian Vetter <jvetter@kalrayinc.com>
    > Reviewed-by: Yann Sionneau <ysionneau@kalrayinc.com>
    > ---
    > drivers/base/platform-msi.c | 2 ++
    > 1 file changed, 2 insertions(+)
    >
    > diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
    > index 4b0b2fe3a7ff..627d8f6b83ea 100644
    > --- a/drivers/base/platform-msi.c
    > +++ b/drivers/base/platform-msi.c
    > @@ -40,6 +40,8 @@ static irq_hw_number_t platform_msi_calc_hwirq(struct msi_desc *desc)
    > {
    > u32 devid = desc->dev->msi.data->platform_data->devid;
    >
    > + WARN_ON(desc->msi_index >= MAX_DEV_MSIS);

    So you just caused a system to reboot if you have panic-on-warn? What
    is someone supposed to do if this is ever hit? Why can't you handle it
    as an error and properly recover instead of just ignoring it?

    thanks,

    greg k-h

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