On Thu, 25 Nov 2021, Greg KH wrote:
> On Thu, Nov 25, 2021 at 12:02:34PM +0000, Lee Jones wrote:
> > Supply additional checks in order to prevent unexpected results.
> >
> > Fixes: b892bf75b2034 ("ion: Switch ion to use dma-buf")
> > Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> > ---
> > drivers/staging/android/ion/ion.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
> > index 806e9b30b9dc8..30f359faba575 100644
> > --- a/drivers/staging/android/ion/ion.c
> > +++ b/drivers/staging/android/ion/ion.c
> > @@ -509,6 +509,9 @@ static void *ion_handle_kmap_get(struct ion_handle *handle)
> > void *vaddr;
> >
> > if (handle->kmap_cnt) {
> > + if (handle->kmap_cnt + 1 < handle->kmap_cnt)
>
> What about using the nice helpers in overflow.h for this?
I haven't heard of these before.
Looks like they're not widely used.
I'll try them out and see how they go.
> > + return ERR_PTR(-EOVERFLOW);
> > +
> > handle->kmap_cnt++;
> > return buffer->vaddr;
> > }
>
> What stable kernel branch(es) is this for?
I assumed your magic scripts could determine this from the Fixes:
tag. I'll be more explicit in v2.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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