On Thu, Jun 12, 2025 at 04:27:41PM +0200, Thomas Weißschuh wrote: > If the assumption is that this is most likely a kernel bug, > shouldn't it be fixed properly rather than worked around? > After all the job of a selftest is to detect bugs to be fixed.
I investigated the history for a bit and it seems likely we cannot change the kernel here. Call it an undocumented "feature". MAP_HUGETLBFS rounds up the length to some value, userspace has to figure that out and not pass incorrect lengths. The selftest is doing that wrong. > If the test is broken on ARM64 64k in general then I am also wondering how > it didn't fail before my change to the selftest harness. It got lucky and didn't overmap something important. Jason
