On 10/9/26 20:04, Lorenzo Stoakes (ARM) wrote: > It makes no sense for a mapping whose contents the kernel does not own to > specify that the range is MMIO. > > Prior to this patch, all in-tree drivers which did so have been updated > such that they are marked as not being mm-managed. The check WARNs and > fails the mmap for any out-of-tree driver that still sets VMA_IO_BIT > without a kernel mapping. > > No functional change intended for in-tree code. > > Reviewed-by: Zi Yan <[email protected]> > Signed-off-by: Lorenzo Stoakes (ARM) <[email protected]> > --- > mm/vma.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/mm/vma.c b/mm/vma.c > index 4f09fb98a2fd..51bdbe08bb02 100644 > --- a/mm/vma.c > +++ b/mm/vma.c > @@ -2796,6 +2796,12 @@ static int mmap_validate_vma_flags(const vma_flags_t > *flags) > return -EINVAL; > #endif > > + if (!vma_flags_test_any(flags, VMA_PFNMAP_BIT, VMA_MIXEDMAP_BIT)) { > + /* mm-managed mappings may not set VMA_IO_BIT. */ > + if (WARN_ON_ONCE(vma_flags_test(flags, VMA_IO_BIT))) > + return -EINVAL;
We do have a helper (vma_flags_is_mm_managed()) but we're not using it because of the VM_IO situation ... That's confusing ... Could we do something like testing vma_flags_is_mm_managed(), but removing the VM_IO flag from the checked flags? Then we can add a comment about VM_IO in the future getting remove from vma_flags_is_mm_managed() ... -- Cheers, David
