Quoting Casey Schaufler (casey@xxxxxxxxxxxxxxxx): > Serge E. Hallyn wrote: > > Quoting Casey Schaufler (casey@xxxxxxxxxxxxxxxx): > >> But each can be expressed as a context, can't it? > >> > > > > A set of contexts (root_u:root_r:root_t:::system_u:system_r\ > > :system_t::...). > > > > There would be a problem if it were stored as a more > > structured type, and if the ->restore handler wanted to > > re-create an actual task_security_struct, ipc_security_struct, > > etc. So the last paragraph in the patch intro was just trying to > > explain why the intermediate layer, storing a generic string on > > the c/r object hash, needs to be there. The thing that is > > not possible is to place the actual void *security or a struct > > task_security_struct on the objhash. > > > > Right. Now why do you need a set of contexts? Because for SELinux, for instance, when checkpointing a security context for a task, we want to checkpoint the actual context, the fscreate context, the sockcreate context, keycreate context, and the task create (exec_create) context. > > ... > > > > > >>> + /* str will be alloc'ed for us by the LSM. We will free it when > >>> + * we clear out our hashtable */ > >>> > >>> > >> Why do you think that you need a copy? Sure, SELinux always gives you > >> a copy, but Smack keeps "contexts" around and making a copy is not only > >> unnecessary, but wasteful. If you free the "context" with the appropriate > >> call (security_release_secctx) you will get the "free allocated memory" > >> behavior desired by SELinux and the "do nothing" behavior of Smack. For > >> free, assuming that you also fix your Smack hook so that it works in the > >> way Smack deems "Correct". > >> > > > > Hmm, that should be doable. Mind you these are not the same as > > secctx's returned by secid_to_secctx. > > Now why is that? If they are different things, what are they? > > What is the difference between a secctx and a context? > I got a bit confused because the word "context" has been > used to refer to the thing represented by a secctx for a > long time. I know, I know, I should come up with a better name. But while an selinux context would be root_u:root_r:root_t the blob I have to checkpoint for a task would perhaps be root_u:root_r:root_t:::null:::null::null:::user_u:serge_r:serge_t:::null thanks, -serge -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@xxxxxxxxxxxxx with the words "unsubscribe selinux" without quotes as the message.
