-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Fri, 20 Jul 2012 09:37:34 +0200 Alexander Boettcher (AB) wrote:
AB> do you see any issues to extend the revoke syscall by a protection AB> domain (pd) parameter ? Currently implicitly the current protection AB> domain of the caller is used. With the extension the caller would have AB> to specify explicitly the pd where the revoke operation should apply to. Currently you don't need a PD capability to revoke capabilities from your own protection domain. And there are situations where you, rather than your parent, may want to revoke capabilities, e.g., cleaning up a receive window. If you make revoke dependent on a PD capability, the consequence is that every PD needs to hold its own PD capability. There are 5 permission bits in a PD capability, all of which currently control creation of objects. We would have to redefine those bits to make room for a "revoke" permission. The permissions of a PD capability could be used for any of the following: * creation of PD, EC, SC, PT, SM objects * revocation of memory, I/O, objects * more? How would you assign those to the available 5 bits? AB> Genode core currently revokes all memory of the client pd subject to AB> destruction. However core has no means to make sure that references to AB> kernel objects are freed which creation has been issued by the client AB> pd directly using the kernel syscalls. Additionally core can't make AB> sure to revoke any mappings of memory, i/o ports and object AB> capabilities which the client received via other channels AB> (services/sessions provided not by core). AB> AB> The same issue also applies to NUL[0], where sigma0 can't clean up the AB> object space of the vancouvers subject to destruction. AB> AB> With the remote revoke core and sigma0 in NUL would be able to make AB> sure that all user level references inside a pd subject to destruction AB> can be freed. Is destruction of a PD the only case where you see a need for remote revocation? Cheers, Udo -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEUEARECAAYFAlAJKK4ACgkQnhRzXSM7nSmAMgCdF/iJACYyuV/WG/ak8Zlc0Hxx 3zIAmPZY70Jve36SK3e5UuKeQ1s5yxg= =5aDu -----END PGP SIGNATURE----- ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Genode-main mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/genode-main
