On Tue, Dec 8, 2020 at 2:49 PM Darrick J. Wong <darrick.wong@xxxxxxxxxx> wrote: [..] > > So what's your preferred poison? > > > > 1. Corrupt random data in whatever's been mapped into the next page (which > > is what the helpers currently do) > > Please no. My assertion is that the kernel can't know it's corruption, it can only know that the driver is abusing the API. So over-copy and WARN seems better than violently regress by crashing what might have been working silently before.