On Mon, Nov 1, 2021 at 12:32 PM Joan Lledó <jlle...@mailfence.com> wrote:
> +kern_return_t
> +memory_object_get_proxy (task_t task, const vm_offset_t address,
> + vm_prot_t max_protection, vm_offset_t len,
> + ipc_port_t *port)
> +{
> + kern_return_t err;
Super minor nitpick: this variable is typically named 'kr' or 'ret',
it would seem. 'err' is more of a userspace thing with glibc's
error_t.
> + vm_map_lock_read(task->map);
> + if (!vm_map_lookup_entry(task->map, address, &tmp_entry)) {
> + if ((entry = tmp_entry->vme_next) == vm_map_to_entry(task->map)) {
> + vm_map_unlock_read(task->map);
> + return(KERN_NO_SPACE);
> + }
> + } else {
> + entry = tmp_entry;
> + }
> +
> + /* Limit the allowed protection and range to the entry ones */
> + if (len > entry->vme_end - entry->vme_start)
> + return(KERN_INVALID_ARGUMENT);
You also need to unlock the map here.
> + pager = ipc_port_copy_send(entry->object.vm_object->pager);
> + offset = entry->offset;
> + start = 0;
> +
> + vm_map_unlock_read(task->map);
> +
> + err = memory_object_create_proxy(task->itk_space, max_protection,
> + &pager, 1,
> + &offset, 1,
> + &start, 1,
> + &len, 1, port);
> + if (err)
> + ipc_port_release_send(pager);
> +
> + return err;
Yes, this looks correct now, at least as far as I understand kernel
internals. Thank you! :)
Sergey
