Hi Greg, On 20.12.2021 09:00, Greg Kroah-Hartman wrote:
On Mon, Dec 20, 2021 at 07:47:30AM +0100, Rafał Miłecki wrote:static void nvmem_cell_entry_add(struct nvmem_cell_entry *cell) { + struct device *dev = &cell->nvmem->dev; + int err; + mutex_lock(&nvmem_mutex); list_add_tail(&cell->node, &cell->nvmem->cells); mutex_unlock(&nvmem_mutex); + + sysfs_attr_init(&cell->battr.attr); + cell->battr.attr.name = cell->name; + cell->battr.attr.mode = 0400; + cell->battr.read = nvmem_cell_attr_read; + err = sysfs_add_bin_file_to_group(&dev->kobj, &cell->battr, + nvmem_cells_group.name);Why not just use the is_bin_visible attribute instead to determine if the attribute should be shown or not instead of having to add it after-the-fact which will race with userspace and loose?
I'm sorry I really don't see how you suggest to get it done. I can use .is_bin_visible() callback indeed to respect nvmem->root_only. I don't understand addig-after-the-fact part. How is .is_bin_visible() related to adding attributes for newly created cells? Do you mean I can avoid calling sysfs_add_bin_file_to_group()? Do you recall any existing example of such solution?
