On Thu, Nov 25, 2021 at 01:03:46PM +0000, Lee Jones wrote: > On Thu, 25 Nov 2021, Greg KH wrote: > > > On Thu, Nov 25, 2021 at 12:46:23PM +0000, Lee Jones wrote: > > > 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. > > > > The fixes tag says how far back for it to go, but not where to start > > that process from :) > > What's your preferred method for identifying a start-point? > > In the [PATCH] tag or appended on to Cc: stable ... # <here>? > > I know both work, but what makes your life easier? Easiest is below the --- line say: --- This is for kernel versions X.X and older. nothing complex. thanks, greg k-h