On Fri, Nov 25, 2022 at 11:19 AM Mickaël Salaün <mic@xxxxxxxxxxx> wrote: > On 24/11/2022 06:40, Greg KH wrote: > > On Wed, Nov 23, 2022 at 12:15:44PM -0800, Casey Schaufler wrote: > >> Create a struct lsm_id to contain identifying information > >> about Linux Security Modules (LSMs). At inception this contains > >> the name of the module and an identifier associated with the > >> security module. Change the security_add_hooks() interface to > >> use this structure. Change the individual modules to maintain > >> their own struct lsm_id and pass it to security_add_hooks(). > >> > >> The values are for LSM identifiers are defined in a new UAPI > >> header file linux/lsm.h. Each existing LSM has been updated to > >> include it's LSMID in the lsm_id. > >> > >> The LSM ID values are sequential, with the oldest module > >> LSM_ID_CAPABILITY being the lowest value and the existing modules > >> numbered in the order they were included in the main line kernel. > >> This is an arbitrary convention for assigning the values, but > >> none better presents itself. The value 0 is defined as being invalid. > >> The values 1-99 are reserved for any special case uses which may > >> arise in the future. > > > > What would be a "special case" that deserves a lower number? > > I don't see any meaningful use case for these reserved numbers either. > If there are some, let's put them now, otherwise we should start with 1. > Is it inspired by an existing UAPI? > Reserving 0 as invalid is good though. I haven't finished reviewing this latest patchset, but I wanted to comment on this quickly while I had a moment in front of a keyboard ... I did explain my desire and reasoning for this in a previous revision of this patchset and I still believe the reserved-for-potential-future-use to be a valid reason so I'm going to ask for this to remain. Several of you may disagree, but unless you can provide a reason why these reserved values would *seriously* break these, or potential future syscalls, I'm going to be stubborn and insist we retain a set of low-numbered reserved values. -- paul-moore.com
