On Mon, Feb 17, 2025 at 02:08:00PM +0000, Ryan Roberts wrote: > A call to vmalloc_huge() may cause memory blocks to be mapped at pmd or > pud level. But it is possible to subsequently call vunmap_range() on a > sub-range of the mapped memory, which partially overlaps a pmd or pud. > In this case, vmalloc unmaps the entire pmd or pud so that the > no-overlapping portion is also unmapped. Clearly that would have a bad > outcome, but it's not something that any callers do today as far as I > can tell. So I guess it's just expected that callers will not do this. > > However, it would be useful to know if this happened in future; let's > add a warning to cover the eventuality. > > Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
