On Fri, Nov 29, 2024 at 5:32 PM Alice Ryhl <aliceryhl@xxxxxxxxxx> wrote: > > This adds a type called VmAreaRef which is used when referencing a vma > that you have read access to. Here, read access means that you hold > either the mmap read lock or the vma read lock (or stronger). > > Additionally, a vma_lookup method is added to the mmap read guard, which > enables you to obtain a &VmAreaRef in safe Rust code. > > This patch only provides a way to lock the mmap read lock, but a > follow-up patch also provides a way to just lock the vma read lock. > > Acked-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx> (for mm bits) > Reviewed-by: Jann Horn <jannh@xxxxxxxxxx> > Signed-off-by: Alice Ryhl <aliceryhl@xxxxxxxxxx> It looks like binder needs a way to check whether a given vma is associated with a given mm. I guess we can do that by adding a method to VmAreaRef that returns a &MmWithUser. This indicates that vma->vm_mm references an mm with non-zero mm_users whenever it's legal to have a reference to the vma. Alice
