On Tue, Oct 29, 2024 at 09:08:22AM -0700, Yang Shi wrote: > On Tue, Oct 29, 2024 at 8:52 AM Lorenzo Stoakes > <lorenzo.stoakes@xxxxxxxxxx> wrote: > > > > On Tue, Oct 29, 2024 at 08:43:04AM -0700, Yang Shi wrote: > > > > > > > > Sorry for chiming in late. This looks problematic IIUC. The patch 5/5 > > > moved arch_validate_flags() before call_mmap() as the commit log said. > > > But shmem_file() does this check: > > > mapping->a_ops == &shmem_aops > > > > > > But mapping->a_ops is not initialized until shmem_mmap(), which is > > > called by call_mmap(). > > > > > > So shmem_file() should always return false here. Did I miss something? > > > > Well firstly this is tested and works so you did miss something :) > > > > Bu shmem_mmap() is not setting mapping->a_ops, it's setting vma->vm_ops. > > > > __shmem_get_inode() and shmem_symlink() set mapping->a_ops. > > My bad, stared at "_ops", but missed "vm" prefix. And shmem_mmap() > can't touch a_ops. Sorry for the disruption. No worries, the various ops are quite confusing and precisely where what happens, I had to double check this myself... :)
